ALCOHOI, AND HIGHWAY SAFETY 1978: A REVIEW OF THE STATE OF KNOWLEDGE Ralph K. Jones Kent B. Joscelyn The University of Michigan Highway Safety Research Institute Ann Arbor. Michigan 48109 January 1 978 Prepared for U. S. Department of Transportation National Highway Traffic Safety Administration Washington. D.C. 20590 Contract No. DOT-HS-5-01217 hwtlrnent i4 available to the U.S. pilblic through t hc National 'I'cc hnicid Information Service. Springfield, Virginia 22 161 ALCOHOL AND HIGHWAY SAFETY 1978: A REVIEW OF THE STATE OF KNOWLEDGE Ralph K. Jones Kent B. Joscelyn 'The University of Michigan Highway Safety Research Institute Ann Arbor, Michigan 48109 Jan u ;try 1 978 Prepared for L! . S. Department of Transportation Nationid Highway Traffic Safety Administration Washington, D.C. 20590 Contract No. DOT-HS-5-01217 The. contents 01' thi\ ~.epurt r.ellcct the 1 iewi of the air thors, who are responsible t'or. the fact\ and ilcc~~r,icy the d~ita prewnted herein. The contents do not nccc\\arily I-eflect the official ~icw\ policy of the Department of Transports- troll. Thij r-eport dot.\ not con3titute :\ jt~indard. +pecification or regulation. Thi\ doc~~rnent d itb~ r1iitc.d under the sponsorship of the Department of Tranipol-tation in the interut of information exchange. The United States Gov- ernment 'ii\Llrnei no liability it\ contents or use thereof. The United States Govcrnnient does not endorse products or manufacturers. -Tr-;~de m:in~~fiictirrers' appear herein solely because they are considered eisential to the ob-iect of thia report. Document is available to the U.S. public through the National Technical Information Service. Springfield. Virginia 22161 AI.COHOId ,AND HIGHWAY SAFt.1.Y 1078: A REVIEW Ot. i THE ST4TE OF KNOWLEDGE Tochaicoi R.port Docu~~~tuti'ka 6. Prfoming Or~ilohon 3. Roctp~mt's Catolag No. 1. R-rc Ma. High~r~y Research In\titt~te fhr l'ni\cr\it) of Michigan Huron kirkua) B B;txter Koad An11 Arhu~,. MI 48109 12. +muins A- MII a4 Adha* Final Reno1.t 2. Gar- Accemsi.n MD. 1. Adds) R,~lph E Jane\ and Kent B Jojcelyn - 9. Pwh~nq Nro 4 Mbamo I U.S. Department of Transport,~t~on I 8. Orglltxdson RW NO. UM-HSRI-78-5 10. loth Untt No. (TRAIS) Nation;ll Highuay Traffic Safety 4dni1ni\t1atron 400 .';c\cnth Street. S.W. Thi\ repoi,t prr\ent\ the ~.c\ult\ (,(.;I compreht.ns~\e re\ ic~ ;ln;ilyhi\ oI'the prohlcni ot'alcohol kind high^,^) cr,i\he\ In 1 the 1;nltcd St;ite\. Buth the n;iture of the ;ilcohol-c.~.n\h prohlem ;~nd soc~et;~l to that prohltm artb treated 1 t.p~derniologic \tt~die\. eapci-imcntal \tudlc\. ;ind ;i,~ntei.nlc;~\~~ic a1.r c\,iniincd in Ihr rebiei\ The short-t~rn1 I I'lrttl~.c ol thc alc.ohol-cr;~\h prohlem I\ plo~ectcd ;lnJ conclu\ion\ ;111d ~.ccornmend;it~on\ relatike to futiire re\ttarch and ;iction program\ ,1rc Jc\cloped. M ,~sh~ngron !O5YO Other i.cport\ pioduced ~~ndcl- IN MOST STATf- - u 0 C 60 C; x 3 2 - ? 40 - - d + Q LL 6 20 s 0 0 .04t 16- .!O+ .24+ .28t BLOOL) ALCOHOL CONCENTRATION (V WiV) Figure 2-2 shows how data from several of NHTSA's Alcohol Safety Action Projects (ASAPs) (Clark and Clark 1973: Ellingstad and Estra 1974: Florendo 1975: Krause and Thomasson 1974: Phoenix. Arizona, Office of the City Manager 1975; Rosen, Mattson and Romslo 1974; Spencer and Ferguson 1975) compare with those from [he selected studies of Figure 2-1. Available documentation on the ASAP studies does not allow a critical analysis of the validity of the data, but it is clear from several of the sources cited above that for a high percentage of fatally-injured drivers who had survived less than six hours after a crash, BAC data were often not available to the ASAP re- searchers. It seems, therefore. remarkable that there is such good agreement between the selected research studies and the ASAP findings. The range of BACs is slightly wider for the ASAPs. but the same trends are evident: many drivers were leg,tlly intoxicated before their fatal crash, and a considerable number of them had been drir,k- ing very heavily. Extensive data collected in a nationwide survey in Canada indicate that this phe- nomenon does not stop at our northern border (Traffic Injury Research Foundation of Canada 1975). In Canada during 1973, 1,006 drivers out of I, I I1 who died less than six hours after their crash were tested for BAC. It was found that 445 (44% of those tested) had BACs of. 11% wlv or greater ('Figure 2-3). Forty-nine percent had BACs exceeding the Canadian limit for legal impairment (.08% wlv). The percentages of drivers killed at given BACs fall well within the envelope described by the selected U.S. research studies shown in Figure 2- 1. The data on driver fatalities in single-vehicle crashes show even higher percentages of THE ALCOHOL-CRASH PROBLEM Figure 9-2. Percentage of drivers fat~tlly injured in crashes with BACs equal to or greater than given levels DATA FROM SEI,~CTEI) AI ~'~HoI. SAFETY ACTION PR~JECTS 0 WASHTEKAW. MICHIGAN. 1%8-1971 (Clark and Clark 1973) V1 0 SOUTH DAKOTA, 1972-1973 (Ellingstad 1974. & )( b AIKFAX, VIRGINIA. 1974 (Spencer and Ferpuson 1975) u 2 no LEGAL. I.IMIT FOR a NEW ORLEANS. 1969- 1973 (Krause and Thornasson 1974) cd DRIVING IN MOST ' a PHOENIX, 1969-1974 (Phoenix, Arizona, Office of the City 0 Manager 1975) 0 a HENNEPIN COUNTY. MINNESOTA. 1969-1973 (Rosen, A Martson. and Rornslo 1974) > 60 LOS ANGELES. 1972-1974 (Morendo 1975) 2 - 'ENVELOPE OF U.S. DATA (NON-ASAP) FROM FIGURE 2-1 > i -1 d i 40 2 5 4 8 20 0 0 .04t .OX+ .lo+ I?+ .lh+ .20+ .24+ .28+ BLOOD ALCOHOL CONCENTRATION (7r W/V) Figure 2-3. Percentage of drivers fatally injured in crashes with BACs equal to or greater than given levels CANADIAN DATA 80 CANADIAN DATA. NATIONAL SURVEY, 1973 (Traffic Injury Research Foundation of Canada 1975) CI) p! a ENVELOPE OF NON-ASAP U S. DATA, FIGURE 2-1 W > CANADIAN LIMIT FOR $ 60 "LEGAL IMPAIRMFNT" c Lr: p: 3 40 5 i 4 t- 2 20 $ 8 0 0 04+ 08 + 12+ 16+ 20 + 24+ .28+ BLOOD ALCOHOL CONCENTRATION (% WIV) .- -. - 4 ALCOHOL AND HIGHWAY SAFETY 1978 Figure 2-4. Percentage of drivers fatally injured in single vehicle crashes with BACs equal to or greater than given levels X CALIFORNIA. NEILSON. 1962- 1968 (Neilson 1969) V1 LEGAL LIMIT FOR @ WAYNE COUNTY. MICHIGAN 1967-1969 (Filkins et al. 19701 d DRIVING IN MOST STATES + CAL.IFORNIA. WALL.ER. 1960-1967 (Waller et al. 1970) ;r: > $0 0 VERMONT, 1967-1969 (Perrine, Walter, and Harris 1971) - d fl WESTCHESTER COUNTY. NEW YORK, 1950-1953 a (Haddon, and Bradess 1959) 3 LL; d 3 60 2 - ? - I d 30 d ir - - d ;~. 20 I I I I I I 1 0 .04+ OX+ lot I?+ I hi- ?Oi .?& .28+ BLOOD A1,COHOL CONCENTRATION (9 WIV) individuals with BACs above the legal limit for driving (Figure 2-4). The data for Westchester County, New York. were obtained from a study by Haddon and Bradess (1959) of single-vehicle crashes. By legal standards. 55% to 65% of the sample were too intoxicated to drive, and 35% to 54% had BACs greater than .15% wlv. Tho variations in these data are quite small except at the higher BACs. where the Vermont data show a much lower percentage of drivers than the other four studies. A wide variation exists throughout the BAC range for drivers killed in multi-vehicle crashes (Figure 2-5). The California data are quite consistent and closely grouped. The Wayne County data are generally much higher. and the Vermont data much lower, than those from either of the two California studies. The percentage of crashes invoiving illegal BACs is lower for multi-vehicle crashes than for single-vehicle crashes, but it is still impressively high at 25%' to 50%. The above figures on the BAC' distributions of fatally injured drivers apply to mot,:r vehicles in general. A recent sti~dy (Baker and Fisher 1977) of fatal motorcycle crashes in Maryland found that the BAC distributions of the motorcycle drivers were similar to those of fatally injured drivers of cars and trucks in that state. 3.2.1.2 Nonjutcrl Crushes. Since Holcomb's study, only three North American studies of nonfatal crashes have taken BAC measurements at the scene of the crash: the Toronto Study in 1951-1952 (Lucas et al. 1955), the Grand Rapids Study in 1962-1963 (Borkenstein et al. 1964), and the Huntsville Study in 1974-1975 (Farris, Malone. and Lilliefors 1976). THE ALCOHOL-CRASH PROBLEM The Toronto Study by 1,ucas and associates was conducted in Toronto, Canada, during evening hours only (i.e., from about 6:30 p.m. to 10:30 p.m.). Data were col- lected on all days of the week except Sunday during the period from December 1951 through November 1952. A total of 433 drivers involved in personal injury crashes or property damage crashes were tested. The Grand Rapids Study reported by Borkenstein and associates is the most exten- sive study of nonfatal crashes conducted to date. Its site was Grand Rapids, Michigan, and its time period was July 1962 through June 1963. BACs were taken at the scene from 5,985 drivers involved in crashes of all degrees of severity except crashes in which drivers were dead at the scene of the crash. Data were collected seven days a week, 24 hours a day. In the study conducted by Farris and ;tssociates in Huntsville, Alabama, data were also collected seven days a week. 24 hour5 a day. BACs from 596 drivers involved in personal injury crashes were taken at either the scene of the crash (about 213) or hospitals. BACs measured at hospitals were carefully monitored by a researcher to avoid biases in sampling and inaccuracies due to time delays in taking the BACs (Farris, Malone, and Lilliefors 1976). Figure 2-6 shows the BACs of drivers involved in all types of nonfatal crashes in Toronto and Grand Rapids. The Toronto data indicate about 15% of the crashed drivers were legally intoxicated by some U.S. standards (i.e., 10% wlv), but the Grand Rapids study showed only about 65? of the drivers at a BAC of ,1092 wlv or higher. One possible explanation for this difference is that the Toronto data were taken in the evening hours when drinking-driving is more frequent (see Section 4.2.2. l), while the Grand Rapids data were taken around the clock. Figure 2-5. Percentage of drivers fatally injured in multi-vehicle crashes with BACs equal to or greater than given levels RO X CALIFORNIA. WALLER, 1%0-1%7 (WaUer el al. 1970) LEGAL LIMIT FOR DRIVING V, @ WAYNE COUNTY. MICHIGAN, 1%7-1969 (Filkins et al. 1970) P? IN MOST STATES CALIFORNIA. NEILSON. 1962-1%8 (Neilson 1%9) W > VERMONT. 1967-1969 (Perrine, Wailer, and Harris 1971) - cr: 0 60 n P? 3 2 - > 40 .J d + < L L 20 0 8 1 I I I 1 I 0 J BLOOD ALCOHOL CONCENTRATION (% W/V) ALCOHOL AND HIGHWAY SAFETY I978 Figure 2-6. Percentage of drivers involved in nonfatal crashes with BACs equal to or greater than given levels 80 0 TORONTO. EVENINGS ONLY. 1951-1952 (Lucas et al. 1955) 0 GRAND RAPIDS. MICHIGAN. ALL HOURS 1962-1%3 C; (Borkenrtein el ;\I. I9641 5 > =: 1 $ 60 5; Z c, x LEGL LIMIT FOR DRIVING Z b IN MOST STATES 2 240 z c 5 'I V 5 z .- 2 -20 0 0 .04+ .OX+ (1 .I!- .Iht .?0+ .?4+ BLOOD ALACOHOI, CONCENTRATION ('7; WIV) Figure 2-7. Percentage of drivers involved in nonfatal. personal injury crashes with BACs equal to or greater than given levels + HUNTSVI L1.F.. ALAR.4MA. 1974-1975 (Farris. Malone, and ~illiefors 1976) 0 GRAND RAPIDS. MICHIGAN. 1962-1963 (Borkenstein et al. 1964) I \ LEGAL LIMIT FOR DRIVING IN MOST STATES I I O+ .04+ .08+ .12- .16+ .20+ .24+ BLOOD ALCOHOL CONCENTRATION (9% W/V) THE ALCOHOL-CRASH PROBLEM The BACs of drivers in personal injury crashes are graphed in Figure 2-7. The Hunts- ville data show that about 13% were legally intoxicated (BAC 2 .lo% wlv) and the Grand Rapids data about YV. Crashes classified as "fatals and driver injuries" (300 crashes) and "other visible injury" (404 crashes) are the basis for the Grand Rapids curve. Finally. Figure 2-8 shows the BAC measurements taken in the Grand Rapids study for 4,570 drivers involved in crashes where there were "no indications of injury," i.e., property damage crashes. Only about 55? of these were at or above BACs of. 10% wlv. Figures 2-6 and 2-7 are of interest from another standpoint. A study employing a multidisciplinary team of accident causation researchers found that impairment by alco- hol was a "prime cause" of 7% of crashes of all types that were investigated and a "prime or contributing" cause in 16% of its crashes (Joscelyn and Treat 1973). This is ro~~ghly same range of percentages that was observed at BACs of .08% wlv or greater in the two studies of crash involvement shown in Figures 2-6 and 2-7. With respect to crash culpability. a recent study found that about 40% of drivers said to be "responsible" for multiple vehicle crashes have BACs of. 10% wwiv or greater, but only 10% of the drivers deemed "not responsible" have such high BACs (Zylman 1974). A study by Waller (1977,) using data from police reports found that 92% of fatally injured Jriwrs with BACs of .lo% wiv or more were "responsible" for their crashes. By contrast. only 64% of drivers with zero BACs were found to have been responsible. The reader should note that most sti~dies of crash causation and culpability have incorporated subjective judgments into their analyses. Thus, they do not provide objec- tive proof that alcohol or any other factor actually ''caused'' or was "respons~ble" for Figure 2-8. Percentage of drivers involved in nonfatal. no injury. property damage crashes with BACs equal to or greater than a given level 0 GRAND RAPIDS. MICHIGAN. 1%2-1%3 (Borkenstein et al. 1%4) --- EXTR4POLATED LEGAL LIMIT FOR DRIVING IN MOST STATES BLOOD ALCOHOL CONCENTRATION (% WIV) 17 ALCOHOL AND HIGHWAY SAFETY 1978 crashes. While the findings of such studies may be used in broadly defining the role of alcohol in crashes, such findings cannot be used to prove that alcohol is responsible for any given percentage of crashes. 2.2.1.3 Adult Pcdcstrirrn Ftittrlitics. As is the case with driver fatalities, BAC mea- surements for pedestrian fatalities have been made by coroners or medical examiners. Thus. the same biases that plague driver fatality studies are also a threat for studies of the incidence of alcohol in pedestrian fatalities. Further, data on pedestrians may suffer from an additional bias due to the common practice among coroners of measuring BACs only of victims who were at least I5 years old. This will cause alcohol involvement to be overstated if the resulting percentages are erroneously applied to (ill pedestrian fatalities rather than to fatalities of pedestrians who are at least 15 years old. Figure 2-9 presents the known pedestrian filtiility data believed to be the least affected by measurement biases. (Two excellent studies conducted by Perrine and associates 119711 and by Haddon and associates [I9611 are not shown because of the very small sample sizes, 14 and 19 respectively, they employed.) The figure shows that 31% to 43% of the pedestrians tested had BACs exceeding .10V wlv. the legal limit for driving. Test results showed that 25% to 37% had BACs in the very high range, i.e.. greater than .I5% wlv. Data from two of the better ASAP surveys ;we in general agreement with this trend (Figure 2-10). although the Phoenix data show smaller fractions of alcohol involvement at all BACs exceeding ,1057 wlv. Figure 2-9. Percentage of adult pedestrians fatally injured in crashes with BACs equal to or greater than given levels no a :'AL.IFORhI,4. NEI12SON. 1962-l%8 (Neilson 1969) + CAL ItOKNIA. WALL-ER. 1960-1967 (Waller et al. 1970) l.E(;AL 1.1M17 FOR DRIVING; 0 WAYNh COUNTY. MICHIGAN 1967-1968 (Filkins et al. 1970) C IN MOST STATES () CANADIAN NATIONAI. SURVEY. 1973 (Traffic Injury Ov) Rejearch Foundation of Canada 197.5) 55 fi, 22 -$ ?& zc s2 40 25 ~3 s$ . i L' 20 0 I 1 I 1 I I I 0 + 04+ oxt lo+ 12+ ,161 .20+ .24+ .28+ BLOOD ALCOHOL CONCENTRATION (V WIV) THE ALCOHOL-CRASH PROBLEM Figure 2-10. Percentage of adult pedestrians fatally injured in crashes with BACs equal to or greater than given levels 0 WASHTENAW COUNTY, MICHIGAN. 1%8-1973 80 (Clark and Clark 1973) a PHOENIX. 1%9-1974 (Phoenix. Arizona, Office of the City Manager 1975) LEGAL LIMIT FOR DRIVING ENVELOPE OF NON-ASAP DATA. FIGURE 2-9 IN MOST STATES 60 DATA FROM ALCOHOL SAFETY ACTION PROJECTS 40 20 I I I I I I I O+ .04+ .OX+ .I?+ .16+ .2Ot .24+ .?8+ BLOOD ALCOHOL CONCENTRATION (9? WIV) Unfortunately. there are no published studies"' of the incidence of alcohol involve- ment in nonfatal pedestrian collisions. Meaningful analysis of this aspect of the alco- hol-crash problem must be deferred until further data become available. Another gap in research on alcohol involvement in pedestrian collisions is the lack of data describ- ing the BACs of the drivers of motor vehicles that have struck pedestrians. Such data would have the effect of raising the percentages of pedestrian collisions involving alcohol. 2.2.2 Drinking Behavior of Dri\. x 3 - z - $20 z $ w k' Q 216 - b z LL E u ? - C 12 > z - LL n >. h -4, - m Q m 2 L LL 5 3 F Q -1 W x - 0 GRAND RAPIDS, MICHIGAN. 5985 NONFATAL CRASHES (Hurst 1974) , + HUNTSVILLE. ALABAMA, 5% PERSONAL INJURY CRASHES (Farris. Malone. and Lilliefors 1976) TORONTO. 423 NONFATAL CRASHES (Hurst 1974) , NOTE: REI-ATIVE PROBABILITY OF INVOLVEMENT EPUALS 1.0 AT A BAC OF ZERO. Q - 1 / I I / 1 , 1 1 1 1 1 1 I I I / 0 / / ' /' /. .// - --' I-- . ii 0 .04 &// .OR I2 .I6 .20 , 0 BLOOD ALCOHOL CONCENTRATION (9% Wlv) -- ALCOHOL AND HIGHWAY SAFETY 1978 hol-crash problem in specific locations around the United States. Yet, despite the wide differences in the study designs and in their geographical locations and dates, the same trends have consistently been observed: Substantial fractions of the more serious crashes involve drivers whose BACs exceed the usual legal limit (3 .lo% wlv) for driving. Smaller but not negligible fractions of "minor" crashes involve drivers who are legally too intoxicated to drive. The risk of being involved in any kind of a highway crash increases rapidly as the legal BAC limit for driving is exceeded. Thus, there is ample scientific evidence to conclude that alcohol-crash is a nationwide problem. but existing data are insufficient to describe scientifically the exact nature or extent of the problem. Faced with this dilemma one can either make no further state- ments pending collection of additional data or make estimates and approximations based on existing data. This report follows the second course in the belief that a rational. if not precise, analysis of available information will be more useful than no anaiysi?. In the remainder of this section such estimates are made with respect to percentages, number. and societal costs of U .S. crashes involving alcohol. In addition, various interpretations are made about the risks such crashes present to drivers with high BACs. 2.3.1 Alc~~hol Crushes Table 2-1 summarizes the results of section 2.2.1 of this report and two other recent reviews of the epidemiology of alcohol involvement in highway crashes (Perrine 1975; Figure 1-15, Percentage of crashes eliminated if given BAC limits had not been exceLded: Hurst criteria VERMONT. FATAL CRASHES (Hurst 1974) d GRAND RAPIDS. FATAL ASD SERIOUS CRASHES (Hunt 1974) \ 0 C;R4ND R,4PIDS. ALL CRASHES (Hurst 1974) + HbNTSVIL1.E. PERSONAL INJURY CRASHES t (F;~rri\. and Lilliefors 1976) 0 .04 .OX I? .20 BAC L.IMIT ('7 U'IV) THE ALCOHOL-('RASH PROBLEM Zylman 1974). This report's-review and the Perrine review are in accord on the percent- ages of crash-involved drivers with BACs exceeding .10'% wlv. The values arrived at by Zylman (1974) fall close to midpoints of the ranges indicated by this report and the Perrine review (Perrine 1975). Unfortunately, neither the Perrine review nor the Zylman review gave estimates of alcohol involvement at other BAC levels, and the latter review considered only fatal crashes. The midpoints of the ranges of values shown in Table 2-1 have been used to develop sum? rough estimates of the national impact of alcohol-involved crashes. These values itre plotted in Figure 2-16, which shows the resulting percentages of crash-involved drivers who would have BACs exceeding the amounts shown. The curves have been used to arrive at an idea of the number of crashes and associated deaths, injuries, and damages that could be "saved" by eliminating the crashes involving the drivers whose BACs exceeded given amounts. The resulting numbers represent an upper limit to savings that could actually be achieved by any real prevention program because (a) it is inconceivable that rill such crashes could be prevented by any societally acceptable programs. and (b) persons who were removed from the higher-risk BAC categories by a prevention program would not cease being involved in crashes altogether but would, at best, only reduce their involvement to that associated with their lower BAC category. TABLE 2-1 E.,timirti~d Pcrc.c>nttrgrs oJ'Crtr.sh-ln~~ol~~~d With BACs Exceeding Given Values 7.\/11, ClYl.\ 11 All Fatal Single Vehicle Fat ill Multi-Vehicle Fatal Personal Injury Property Damage s01irc C' Th15 Report Perrlne Zylrnan This Repol t Perr~ne Lylman Th~s Perrine 7ylman Th~s Perr~ne Zylmnn4 This Report Perr~ne Zylrnan BAC. ';r, ~t-lv - . - - - - - .I0 .I5 - 40-55 29-43 40-55 - Perline 1975 Zy lmun 1974 ALCOHOL AND HIGHWAY SAFETY 1978 Figure 2-16. Esrimated percentages of U.S. crashes eliminated if all drivers with BACs exceed- ing a given amount did not crash 60 r (PEDESTRIANS EXCl.UDED) RAC LIMIT ('7 WIV) (0 The reader is cautioned against concluding, purely on the basis of epidemiologic evidence, that all such prevented crashes would have been cairsed by alcohol. The technique developed by Hurst (and described in Section 2.2.3) for calculating the maximum effectiveness of alcohol-related crash prevention programs allows ;his second factor (i.e.. reduction of the risk of crash involvement as opposed to eiimination of that risk) to be taken into account: and it results in a more realistic assessment of the costs of crashes involving drinking drivers. The only problem in using the technique for obtaining national estimates is the need for controlled studies to provide the input data. The only really valid controlled study of the most costly type of crash, the fatal crash, is the Vermont study, which was conducted in a predominantly rural setting. Neverthe- less, it should be of interest, for purposes of comparison, to develop some estimr?es based on Hurst's criteria. The basis for these estimates will be Figure 2-17, wk.:h presents smoothed versions of the curves in Figure 2-15. The curve for personal injuly crashes in Figure 2-17 is based on a composite of applicable Grand Rapids and Hunts- ville data. Figure 2-17 may be used for estimating how many crashes would be eliminated by changing the crash risk of drivers with BACs ubolae a given amount to a crash risk associated with uxactiy that BAC. For example, if one could by some means replace the crash risk of persons who drive with BACs ubo\?c .lo% wlv with the crash risk of persons who drive with BACs of clxactly .lo$? wlv. approximately 29% of all fatal crashes would be eliminated. A BAC "limit" of ,0595 w/v would eliminate some 42% of all fatal crashes, etc. a rrl 3 Z 40 Li > ;L) Z3O- v, Lr] z v, , FATAL CRASHES L h PERSONAL INJURY PROPERTY DAMAGE .OK I? .20 THE ALCOHOL-CRASH PROBLEM Fig111.e 2-17. Estimated percentages of' U.S. crashes eliminated if alcohol-related crashes were r.educed according to Hu1.5t's criteria L.\t~t,lrrti~il it? Nrrmbcr ~/'Cro.slie,s to Prc,\,enting Alc~hol-Related Crushes: 1975 .l(l C 10 I, - I_ - / ?: - y, 20 & I 'A d z L - - [I'I DF STKIANS tXC1 1 [)I Dl , - - FATAL CRASHES PL RSOIUAL. IhJLR'r PKOPLRTY D4M4GE (Pcdr.vtricrn,s E.uc,lridcd) BA C Lit~rif fr;li CI .05 and abuve I0 and ~tboce .I5 and ;ihove The Hurst criteria are discussed in section 2.2.3 of this report. Numbers are based on percentages presented in Figures 2-16 and 2-17. and 1975 accident rates (National Safety Council 1976). tiI,KST CKITEKION: Lo~~,c.rod Prohohilit,~ (-r(~.\lt 111 I ol~.c,trlrtlr Tlto.\(, Miitl~ Gil.c,tl BAC l.i,~,(,I\ Probuhility of Crcrsh In\~trl~~et~~r~nt to Zrro Ti1o.c.u Wit11 C" BA C' Lr 1,eIs ' " Proport!' 1)trnlrrgc~ (.rri S/IO,\ 965.000 62 1.000 1.trrol C't.ci.\lro\ 13.600 9.400 Futlrl Cru.vho.\ 17,900 15.200 1 1,600 Pro1 II~~/II.,Y CIYI .I 11r.s 118.800 83 .900 5.300 Persottul Injury Crushes 183.600 120.000 65,400 Property , D~tnuge Crushes 1.296.000 765,000 229.500 ALCOHOL AND HlGHWAY SAFETY I978 Table 2-2 shows the estimated number of fatal. personal injury, and property damage crashes (nonpedestrian only) that would have heen prevented in 1975 if drivers who exceeded the BAC limits shown either had not cra'shed at all or had crashed at reduced rates in accordance with Hurst's criteria. The seriousness of the alcohol-crash problem is indicated by the fact that as many as 9.400 to 15.200 Pita1 crashes, 83,900 to 120,000 personal-injury crashes. and 621.000 to 76.000 property-damage crashes would not have occurred if the legally intoxicated drivers had not crashed at all or had crashed at the reduced rates indicated for nonintoxicated drivers. Still. it cannot be stated with certainty just how many of these crashes were actually crrrlsod by alcohol. The societal costs associated with these alcohol-involved crashes may be estimated by applying cost factors developed by NHTSA (U.S. Department of Transportation 1976b). These cost factors permit one to calculate the long-term losses in societal welfare (a) to the indibidual (personal consl~mption loss. pain and suffering. assets consumption loss). (b) to society as a whole due to the distribution of resources away from welf:i~.e-/>~.odric,i~~~<~ and toward compensation for losses (medical care costs. property damage costs. legal and court resources. insurance costs). and (c) to society due to direct and indirect losse~ the productivity of those involved in crashes (Faigin 1975). The resulting societal costs art. presented in Figi~re 2-18. u.hich indicates that some $4 to $6 billion dollars in 5ociet:tl welfare losses could have been prevented in 1974 by redi~cing or preventing crashes involving illegally intoxicated drivers (BAC 2 .10q w/v). Even greater savings could ha~e realized by reducing or preventing crashes ~,ith BACs euceeding .O5Ti hi\ ($6 to $8 billion). Large savings would have been possible eben if only dri~ers the very high BACs had been prevented from crashing ($2 to $4 billion). Again. these represent the maximum possible savings that could be achieved by an) real-world alcohol-safety program and are presented only to illustrate the upper bound to the problem. 2.3.2 Ale-ohol ill Podcstritrn Colli.vio~l,\ In Table 2-3. the present report's estimates of the BACs of fatally injured adult pedestrians are compared with estimates developed in the Perrine (1975) and Zylman (1974) reviews. As was the case for BACs of drivers, there is accord among the studies for pedestrians with BAC 2 .lo% wlv. justifying the development. as in this repout, of estimations of impact which use the midpoints of ranges of values. TABLE 2-3 Estirntrtcd P(jrc.c.ntng~s od' Futully Injirrc~tl Adrilf Pct1rsj1.irrn.s With BACs E.rcrrdin,q Gillen V~lries .SO/ll lJ Present Report Perrine Zylman Pel-rine 1975 "'Zylman, Blomberg. and Preuj9t.1. 1975 THE ALCOHOL-CRASH PROBLEM Figure 1-18. Estiniated maxim~~m costs savingc in the U.S. due to prevent~ng alcohol-re- Ii~tcJ IPt.L)ESTKIAYS L'.X<'I.Cli)EI). 1975 CRASH RATES) "" '. 0 0 04 08 I 2 16 10 BAC LIMIT (% W~i'd) ALCOHOL AND HIGHWAY SAFETY I978 TABLE 2-4 Estilntrtctl Natio11~1 1)11p To Al(~o/~ol-ln~~olr~c~d Frrtalities ill 1975 Use of these percentages ~iith accident data (National Safety Council 1976) results in the finding that some 2.300 fatally in.jured adult pedestrians had B4Cs exceed- ing .lo'; w I, in 1975 (T;ihle 2-4). The costs to society of these crashes are over a half-billion dollars. It is not pos\iblc to apply Hurst's criteria to these calculations bec;it~se ot'the lack of applicable cont~.olled studies of pedestrian collisions. Also. there are insufficient data to develop any ~~set'ul of alcohol involvement in pedes- trian in,iuries which were noni'at:~l. 2.3.3 Risk of'Itl\'ol~,o~rlc~~lt C'rrr.s/lo.\ The epidemiologic studies clearly sho~v that high-BAC' drivers f'ice a much higher crash risk than low-BAC' drivers. For example. the Grand Rapids and the Vermont ~tildies indicate that illegally intoxicated drivers are six to twelve times more likely to be involved in fatal and serioi~s in,ji~ry crashes than nondrinking drivers (Figure 2-17). Dat;~ from the Toronto and Gr:lnci Rapids stildies indicate that the involvement fre- quency of illegally intoxicated driver is 1% to 3'!1 times that of nondrinkers for less serious crashes. The alcohol-crash risk could be calculi~ted for groups of drivers and nondrivers more sharply defined than those abovc.. Untbrtunately. the data for making such calculations on a national basis are so limited that the ~'esults woi~ld be little more than speculation and would probably serve more to confuse than to clarify. More will be said about the characteristics of drinking drivers in Section 4.0 of this report. 2.4 SUMM.4RY AND CONC'1,USIONS Public concern about a suspected alcohol-crash problem was expressed at least 70 years ago. and scientific investigations to determine the nature of that problem have been underway for over 40 years. A major tool for studying the role of alcohol in highway crashes is the epidemiologic study of the incidence of drinking among various population of drivers, particularly drivers who had crashed and noncrash-involved drivers who had been exposed to highway environments similar to those in which the crashes took place. Epidemiologic studies have been conducted for many years in many different loca- tions. Their objectives. designs. and executions have varied widely. for no national THE ALCOHOL-CRASH PROBLEM program has existed for rnerhodic;~lly investigating the many variables that describe the complex driver-vehicle-envi~.onment sur~.ounding highway crashes. For the most part. research ha4 proceeded in the directions ot' greatest interest to individual investigators rather than along lines that hoirld support the objectives of coordinated psograms of risk reduction. ('onversely. coordinated risk reduction programs based on a pseliminary ~~nderstunding the problem have been unablc. for the most part, to generate sufficiently rigorous data for wide application in impro\.ing ~inderstanciing. As a result, psoblem identification. the first step commonly taken in such programs, muyt he performed by piecing ropether bits i)f infornlation gleaned from many explora- tory studies necer intended for global application. Such an approach is scientifically h,., . birt necessary, if' fr~rther progress is to be made. In man) r.espect4 the picture that enicrges is semarkably consistent. Some 40-55q of all dsivcr fatalities in the sti~dies had blood alcohol concentratiunb high enor.rgh to be considered. legally. too into.iicated to drive. in most stares (i.e.. b.4C 3 .10% iiclv). An (:\en t~ighes. percentage (55--hir;) of drivers M ho were killed in single-vehicle crashes had B.4Cs of at Ieiist . lo!; M/I'. Smaller but still significant tractions of drivers involved in in~i~ir) (9- 13'f and propcrty damage crashes (CV) evere illegally intoxicated. T'hc national impact of these figures is enormous. If one assumes that the national percentages lic at the midpoint4 of the ranges stated above. then. in 1975. the following n~rnibers of crashes in~olvetl illegally intoxicated dri~ers: @ t'atal crashes: 15.700: personal in.jury crashes: 120.000; and property damage crashes: 765,000. The societal co~ts these . IOCTr wlv) than drivers who are not responsible for crashes. 3.0 ALCOHOL EFFECTS ON PEOPLE Thc~gh studies have provided strong evidence that drinking is asso- ciated with increased risk of crash involvement. they are not an appropriate tool for addressing other fundamental questions about alcohol ss a causal factor in crashes. For example, epidemiologic studies have not been able to rule out the possibility that other circumstances that just happen to be coincident kith consumption of alcohol might be more significant causal factors than is alcohol consumption. (This issue will be dis- cussed in detail in Section 4.0 of this report.) Nor can these studies indicate just how ingestion of alcohol results in impaired driving performance. Knowledge about ,the effects of alcohol on human behavior would help in determining the probability that alcohol alone (in given amounts) can sufficiently impair the driving performance of many people to be a primary causal factor in many highway crashes. For the purposes of this report, the scientific study of alcohol effects on people has been divided into three categories: * biochemistry of alcohol, physiological effects of alcohol, and behavioral effects of alcohol. The first two categories deal with the absorption and metabolism of alcohol in the human body. the measurement of alcohol presence in the body, and the acute and chronic physiological effects of alcohol on various parts of the body. This material is germane to the present re,.or.t because of the need to describe the relationship between behavior and alcohol in quantitative terms, that is, in terms of amount of alcohol consumed. It is also important to understand some of the more basic interactions between alcohol and the bodily components, especially those interactions that influence behavior. The third category of alcohol studies is of more direct interest here. It is concerned with alcohol's effects on human behavior, particularly behavior related to driving. Top- ics covered include the processes through which alcoholic intoxication is brought about, the specific site(s) of alcohol's effects in the body, and the effects of alcohol on the range of behavioral processes. Studies of alcohol influence on the simpler behavioral processes (e.g., interactions of nerves and muscles) are of special concern insofar as ALCOHOL AKD HIGHWAY SAFETY 1978 thcy rel;~tc to driving perfosm;~ncc. Studit\ c)f thc c'fi'cctl; of ;~lcohol the performance of sinii~l;~lctl i~ct~~;\l tasks ;lrc of'obvioi~~ 'The remainder of this section of the report discusses tht tindings of studies believed to be representative of some of the better research in the areas outlined above. No attempt is made at an exhaustive tseatment of the literature. which in some areas is far too extensive for a complete revie& in a document si~ch as this. However. references are presented which will enable the reader to engage. in more in-depth study of topics of particular interest. 3.1 BIOCHEMISTRY AND PHYSIOLOGICAI, EFFECTS OF ALCOHOL The active ingredient in distilled spirits. wine. and bees is ethanol, a member of a family of chemical compoi~ncis kno~n monvhydsic i~icohols. Ethanol (also called ethyl alcohol, grain alcohol. and, morc conlmonly. simply "alcohol") is simpler in chemical composition than any of the othes alcohols except one. methanol. It is soluble in water. weighs a bit less than water (specific gravity = .79) and has a lower boiling point than water (78.3"C) (Wallgren and Barry 1970: L,eake and Silverman 1971). Although alcoholic beverages appear in a great variety of colors. flavors. and bou- quets. their chief constitirents quantitatively are ethanol and water. Other components appear to have only minor pharmacological significance (Wallgren and Barry 1970: AMA Committee on Medicolegal Problems 1970). although some studies (Katkin et al. 1970) indicate that psimary :tlcohols other than ethanol (called "congeners") may in- crease risk-taking and decrease psychomotor performance. A "typical" drink (about 314 ounce of alcohol) is provided by the following amollnts of alcoholic beverages (Hall 1974): a ''shot" of distilled spirits (1'12 oz, of 100 proof alcohol). a glass of fortified wine (jll:! 07. of 209; alcohol). a larger glass of table wine (5 07.. of 12% alcohol). a pint of beer (16 oz, of 4':'n% alcohol). Alcohol is most commonly absorbed into the body through the gastrointestinal tra~ although it may also be absorbed through the membrane of other tissues. e.g., skiq. bladder, oral cavity. Absosption occurs through the simple process of diffusion-alco- hol does not have to be digested before entering the blood. When the route of absorp- tion is through the gastrointestinal tract, approximately 25% of the dose passes through the stomach wall and the remainder through the intestines (Hall 1974). The rate of absorption of alcohol, when taken orally, depends on the quantity taken, its concentration, and especially on the other contents of the gastrointestinal tract. Food delays absorption. When alcohol is taken with a heavy meal, up to six hours may be required for complete absorption (Wallgren and Barry 1970). The effect of the concen- tration of alcohol in the drink on the absorption rate is minimal for small doses but becomes noticeable at larger doses, peaking out at about 20-30% dilu:'on for doses of ALXOHOL EFFECTS ON PEOPLE ahout two to three ounces (Wullgren and Barry 1970; AMA Committee on Medicolegal Problems 1970). After absorption wirhin the body. alcohol is distributed among the organs and tissues in proportion to their fluid content. The speed with which different organs reach equili- br.ium depends upon their t~lood supply (AMA Committee on Medicolegal Problems I9iO). Organs such as the brain and liver will reach a given concentration faster than will. for example, bone. ~lcohol eliminated from the body thro~~gh combined processes of oxidation and elc<~.etion. evidence e~ists Committee on Medicolegal Problems 1970) that oxidation is by far the more important of the two. converting over 90% of the iricohol in the blood to c;trbon dioxide and water and reieasing energy in the process. 'The first step of the mt.twbolic pi-occss ~cciirs in the liver 1vher.e an enzyme helps to convert the aliohol intd ;inother chemical compound, acetaldehyde. Other tissues ~!,sist in the further metabolism of this compound (von Wartburg 1971). Re~.earche~.s found that the average rate of elimination of alcohol from the body i5 abwt .015r/r u,/v per hour (W;tllgren and Barry 1970). This rate of elimination is indcilcndent of the level of BAC except at very low concentrations (e,g., -01%). Koirghly speaking. the average person eliminates. each hour. one of the "typical" drink: described above. No practicable means of significantly acccle:.nting the elimina- iion of alcohol has been cli3r:overed yet. although some research in this area has been conducted (see section 6.2.1 ). 'These :ire many method3 of nle:~su~.ing amount of alcohol in the blood. Most of these test the blood directly. rather than some other fluid or tissue (for example, urine 01. saliva). Blood collected from a vein or from capillaries is usually preferred when a direct indication of alcohol concentration in the brain is required. Laboratory facilities are required to separate the alcohol from the blood and for the subsequent quantitative determination of the alcohol (AMA Commitree on Medicolegal Problems 1970; Dubow- ski 1977). In 1917. Bogen intrc)duced breath-alcohol analysis as a medical tool in the United Statcs (AM,4 Committee on Medicolegal Problems 1970). Since then a number of de- \ices have been developed for use both in the laboratory and in the field. Moulden and \ u'tc (1975) have reviewed techniqires and instr.uments currently in use in the U.S. Modern breath :esters cat1 he quite precise in their quantitation of breath alcohol. Tests of the Breathalyzer. :I device which uses photometric methods. were conducted over a period of nearly ZU ),eai'q and indicate high precision when compared to cali- brated devices uhich measure blood alcohol directly (AMA Committee on Medicolegal Problems 1970). Other intspensive and highly portable bseath testers are available for screzning purposes in the field where less precision is needed (Moulden and Voas 1975). More will be said (in Section 5.0) about the various types of breath alcohol testers and the problems of using them operationally in the section of this report which discusses u,ays of dealing with the drinking driver problem. Evidence of alcohol intoxication is most commonly apparent through observation of the behavioral and emotional effects of alcohol consumption. (These effects are discussed .-_ _ ALC'OHOL ANL) fllGHWAY SAFETY 1978 in some detail in Section 3.2). The gaiety of cocktail chatter. the staggering drunk, and the man who cries in his beet- are easily recognizable stereotypes of the effects of drinking. These and other behavioral and emotional effects of drinking vary among individuals and among cultures. However. there is a universal pattern of reaction to drinking, beginning with feelings of relaxation and pieasure and progressing to heightened emotionalism and disturbances in psychomotor functioning. Though these effects are the most easily ob- servable, thzy are secondary manifestations of the actions of alcohol on the human body. The primary effects of alcohol intoxication are physiological. The physiological effects of alcohol intoxication have been categorized as acute and chronic. Acute effects are short term in that they result in only temporary behavioral changes: and they do not usually result in permanent damage to the human body, though impairment of certain physiological processes may extend beyond the time when alcohol has left the body (AMA Committee on Medicolegal Problems 1970: Wolkenberg 3975). Acute effects may begin to appear very soon after the ingestion of alcoholic beverages. As the amount of alcohol in the body increases, the depressant effect of alcohol increases, and the physiological processes of the body are increasingly im- paired. The acute effects of alcohol intoxication on the human body include alterations in the functioning of the centl,;il nervous system. temporary swelling and inflamation of the liver, increased i~rinary output. increased heartbeat and blood pressure, irritation of the lining of the stomach, distortion of the water balance of the body through redistribu- tion of water. impairment of the sexual function. and restless sleep (AMA Committee on Medicolegal Problems 1970: Carroll 1970; C.S. Dept. of Health, Education and Welfare 197 1 ). The most significant of these acute physiologicai effects is the impact of alcohol intoxication on the central nervous system. The behavioral and emotional effects of alcohol consumption are caused by the depressant effects of alcohol on the brain. The measurement of BACs is really an attempt to determine, indirectly. tht amount of alcohol in the brain. Since it ih not i~sually possible or practical to extract samples of brain tissue for this measure. materials from other parts of the body are employed. 'Thus. as discussed previously. the presence of alcohol in the body is most commonly measured through chemical tests performed on samples of blood, urine. andlor breath (AMA Committee on Medico1eg;il Problems 1970). The sensory effects of alcohol consumption appear in response to very small doses of alcohol. Nystagmus, a condition involving rapid and involuntary movement of the c Je- ball from side-to-side, occurs as early as 15 minutes after ingestion of alcohol. Les:er effects occur with the other senses. Taste and smell become less acute. The use bf alcoholic beverages to lessen pain compares well with that of other analgesic sub- stances. There appears to be little effect of alcohol consumption on hearing (AMA Committee on Medicolegal Problems 1970; Levine. Greenbaum, and Notkin 1973). Just how much alcohol must be ingested for acute alcohol intoxication to occur varies from person to person. Relevant variables are body weight, contents of stomach, physical health. and the tolerance which the individual has developed to the effects of alcohol. Researchers have found that at a BAC of 0.15% wlv, at least half of their subjects show signs of gross intoxication. Many people appear to be intoxicated at lower BACs (AMA Committee on Medicolegal Problems 1970). As stated above, acute alcohol intoxication ALCOHOL EFFECTS ON PEOPLE sarely result, In permanent damage to the human body. However. it is posible for coma to result ~f a BAC of 0.40r7 w,\ i+ reached. A comatose conditian may last for 10- 12 hours before death occur, a$ u resuit of the paralysi5 of the regprratory center. The effects of the cons~rmptioil of alcoholic beverages on the human body become chsonic when large amounts of aicohol are ingested over long periods of time. .4rnong thi: possible chronic effects of heavy ;~nd sustained consirniption of alcohol are nutri- tional imbalance. reduccd \cnsitivity of the nerbous system to the effects of alcohol. withdrawal symptoms when the intake of alcohol is abruptly decreased. increased risk itrnong some gruuyj of deveioping ',ertain kinds of cancer, increased risk of heart diseitse among fiwmer- drinkcrc. sho~.ter life expectancy among heavy drinkers. mi~scle \\c.:tkness. hormonal in~bal:rnce. and sustained irritation of the mouth. esophagus. and \tonl;tct~. st. sir l t ing in impaired S~rnctioninp of the gastrointestinai trhct (Lieber 1976: U.S. Dept, of Health. Edi~catian and Welfare 1971 ; U.S. Dept, of Health. 1:ducation and Welfare 1974). Pi,olonged issitation of the gastrointestirii~l tract by alcoholic beverages. the possible pi.esence ;,I alcoholic heveriigcs of' c;ircinogenic substances. the enhancement of the eficc%ts of carcinogenic substances in those person.; who both drink and smoke. and ,;i :ohol related nutritional imtxilancc are LIII kictor.5 which mdy contribute to the increased sisk of cancer among some grcrilps (U.S. Dept. of Health. Edi~cativn and Welfare 1974). However. there are at least ~LIO of the health problems believed to resi~lt from the use of alcohol. One coi~nterindication is that mocierate drinkers appear to he less prone to heast dise~tse than either former drinkers or abstainers. A second coi~nterindication is that though heavy drinkers have a shorter life expectancy than nloderate drinkers. moderate dsinkers have longel- life expectancies than abstainers (U.S. Dept. uf Health, Education and Welfare 1974). Not all the issues related to alcohol and health have been I-esolved, as the preceding statenients reflect. Of major concern to many researchers are the effects of alcohol on the liver. These effects arc' known but not completely 1.1nderstood. Many researchers I-l-,lie~,e to be 21 direct liier toxin, and others remain convinced that it is the malni~ti rcwlting from chronic irse of alcohol rather th;m alcohol itself which leads to cisrhosi, OF the liier (1' S, ilept, of Health. Ir of intoxicated persons to i.~nderestimate their performance i~npa~rlnent been ubssr\,~eJ in some laboratory experiments (Goldberg 1943: balipr-en and Barry 19701. Why a per sot;'^ onn e;tiniate of the degrading effect of ,;!coho1 o? his performance is sornctimi.~ is,> than the actuai effect is not knowr,. Beha\/iul.al ;.ese~irch suggt:sts that the tendcncy (11' aicohol to remove inhibitions (McLelland et al. 1972) may be a factor, !-!it i'nrrAc. be other factors. Thete are indications that alcohol may impair combineci ~tensori-motor tasks (e.g., tr-ackizgi most than it impairs more intellectt~al activitm (e.g., arithmetic calculations) (Sidcil and Pless 1971 J. Experiments also suggest that one's perfo~mance in complex Str!i{ ,I-motor tasks (e.g., card sorting) is more impaired than in simpier tasks (Lewis I';'.-I:. Evidence [hat sensori-motor performance might be more impaired in light dr1nker4 by moderate amounts of alcohol than in heavy drinkers is provided by one study (Goodwin. Powell. and Stein 19731. L,aboratory experiments provide evidence that alcohol impairs both short-term and long-term memory. Earlier experiments had indicated rather small effects on short-term memory. unless the maferiai to be memorized bas conlplex (M'allgrsn and Barry 1970), but more recent research has shown much larger detrimental effects. even for less compiex materials (Ehrsnsirrg et al. 1970). Experiments with long-term memory have jhown consistently larger efrects, particularly on the retention in one state (drunk or sober) of infor4mation that was learned in another state (sober or drunk] (Walgren and Barry 1970). An extreme example of ihis effect i> toral inability to recall any events that <~c~.:urred intoxication (blackout). The exact relevance to highbay safety of these tiilt~iiig~ be stated at this time. Mosr of the research contlucted on the effects of alcohol on memory has employed alcoholics as subjects, th:: 1l;niting its general applicability. Experiments comparing alcoholics with nonalcoholic~ tend to show that both short-term and long-term memory effect\ are more pronl:uncttd among alcoholics (Weingartner and Faillace 1971a). One such stiidy (Weingarrnci. and F'aillace 1971 b) yielded the ur~expecred but highly relevant finding that aicohoilcs may be less sensitive to punishment than nonalcoholics. The nonalcoholics in this experiment had a poorer recall of words associated with punish- ment than ocher words, but the alcoholics showed no difference in recall with respect to punishment. The studies cited abo~e some clues as to how alcohol might affect driving perfor.rn:znce. Hou,ever, they do not show how the observed effects are explicitly re- lated to crashes. ALCOHOL AND HIGHK4Y SAFETY 1978 Laboratory experiments on the effects of alcohol on human behavior are useful for developing a fundamental knowledge base from which basic concepts can be formed and valuabl-e insights gained. However, they are seriously limited in their applicability to specific areas of human performance because of the difficulty of relating their ab- stract activities and conditions to those experienced in everyday life. It is difficult to understand, for example. exactly how the results of a Romberg test or an experiment in sorting playing cards conducted in a laboratory setting applies to the tasks that must be performed in driving an au~omobile on a busy expressway at night. Attempts to get more realism into experiments on the effects of alcohol on driving performance have appeared in two basic forms: using driving simulators to approximate actual driving conditions in the laboratory and using an actual vehicle on a carefully controlled driving course. While these two types of experiments provide :I closer approximation to real life driving conditions than the laboratory experiments described in Section 3.2.3, the use- fulness of the findings of these studies is limited. In simulator and closed course driving experiments the speeds which are i~chiev:tble are much lower than average highway speeds and tests last for relatively short time periods. In addition. the tests require the use of much simpler skills than required in ordinary highway driving. Further. the driver is aware he is being tested and may react differently from how he would in an actual driving situation. These limitations exist because. legally and ethically, it is not accept- able to endanger the subject by exposing him (and the public) to the dangers of driving under the influence of alcohol for extended periods of time, at high speeds and on public roads (Huntley 1974). The results of the driving sinlulator studies have been highly conflicting, leading one reviewer to observe that "there appears to be no driving behavior on which the effects of alcohol have been reported more than twice with complete consistency" (Heimstra and Struckman 1974). The authors of that study report that there was sufficient consistency among the studies to suggest that the impairment of the higher mental processes was a major contributor to reduced driving performance. This conclusion is supported by an- other simulator study that concluded that moderate amounts of alcohol impaired perfor- mance of complex, concurrent tasks more than simple tasks (Landauer and Milner 197 1). Two recent simulator studies. involving subjects with moderate BACs, indicated th;tt braking response is degraded by alcohol (Rafaelsen et al. 1973) and that persons are more likely to continue through an intersection on a yellow light after drinking (Lewis and Sarlanis 1969). In a study by Snapper (1973) on a closed course driving range, comparisons were made of the performance of light and moderate drinkers at BACs of 0.0. .05, .lo, and .15% wiv. He found that psychomotor impairment is more relevant to accident causa- tion than impaired decision-making. Snapper stated that this finding contradicts the earlier work in this area by Lewis and Sarlanis (1969). possibly because the driving task defined by them was not very sensitive to psychomotor impairment. ALCOHOL EFFEC'TS ON PEOPLE The extent to which a driving simulator is able to interject more realism into studies of ciriving perfc)rmance is not known. In comparison of the performance of experienced taxi drivers on tests of psychomotor skills. simulators used in driver training, and actual :lo u:;~y of stating these degr:tclations in terms of crash risk. Sirnuiiitor studies of beh:~vio~ to be related to driving have shou,n highly c~)nflicting results, bill jeern to indicate that one's ability to perform complex tasks is rnolc impaired by alcohol than fol simpler [asks. The relationship between simulator t'1sh4 and street driving has been se~~iously in the literature. i~'rosc.d course driving experiments indicate that the ability of many drivers to perform p.,,.king maneuvers bcsonies impaired at low BA('s (i.e.. .04C4 to -06% wlv). Closed i.iiL!i.st. driving performance itt low speeds appears to be degraded for average drinkers RACs of .OX5'( to .10V wlv, but less so for heavy drinkers. Closed course driving performance at moder:tte speeds has been shown to be impaired at BACs as low as .o~; .o-K,: Thus. there is evidence th~it some behavior that appears to be related to driving pe~.form:inse is impaired by alcohol. The cxact nature and extent of these impairments and their frequency of occurrence among different individuals at given BACs cannot be \~ii:ed. Lacking explicit relationships between the behavior studied and critical driving tasks. it cannot be said psecisely how these impairments affect one's probability of being involved in a crash. What emerges, however, is thar behavior that has been \?~~:.iicd consistently and significantly impaired in virtually all individuals as BACs i~ytproach .!O% LL'/V. persunb, p:irticirlarly lighter drinkers, have shown impair- ment at much loher BAC'c. Orlly a relative few of the heaviest drinkers appear to suffer little impairment at BACs nuch greater than .lo% wlv. 1,.0 PEOPLE WHO DRINK AND DRIVE In the preceding sections of thi5 report. data have beer, presznieii ushicil indicate, when i:ikcn toyether. that consumpticln of ;ilcohol does. in fact. imp;til. dri; ing beha\ ior and is a miijur. factor in a large ntimber of highhay cl.ashes. The foci~s this seclior: is on the heha: ;dr and charactc~.istics of people u,hose patrcrns of drinking and J!-i\~ing to cr.c.att abnornally high risk of' in\,olvement in c~.:~siies. findings which describe tat10 g.oups of drivers--drinking dri~crs in criishes and driielking drivers *lsing the 1.;!.?11s not involved in crii~hcs---ii1.c euamincd. 'Two basic types of ~.csearch activity pr.o.\ide the data used here. The firs; type is the epidemiologic study L\ hich wah 11si.d ~'xfcnsi~ely Section 2.0 to de\,ciop broad state- rnents describing the drinking-driving problem. These studies are examined in more dcr;lil in this section to provide (harpel definit~~)nc groups of drinking drivers. The ~ecund type of research acti\ity involves surveys and testing of selected groups of people in order to Ieiirn mure ;~ho~lt demographic charactei-istics. drinking and driving habits, physical and psychological attributes, and attitudes of drinking drivers. Studies ~hich to ~.el:~tc sur\ey and test data to findings from epidemiologic studies are also consider.cd here. The specific findings on pcoplc who drink and drive are preceded by a more general ~,lisi:ussiun of drinking and drinking patterns in the U.S. and eisewhere. Current statis- tics on alcohol consumption :ire provided along with some of the nore widely used definitions of types of clrinket-\. Such information i3 essentiitl to vieuirg the alcohol- crash problem in its prop,: pt., jpective. that is. within the context of the larger societal problem of which it is a r:it.:. 4.1 DRINKING AND DRINKING PATTERNS Over the last several decadec, cons~~mption alcoholic beverages has increased in the L.S.A. among member> of the drinking-age population (15 years and over). This I'he data presented below on appal.en1 consumptron of :rlcohol arc taken from publications of the Rutgers Centel of Alcohol Stt~dies. sources of pussihle error In deriving these data have been described in the Center'i annual reports of alcohol-related statistics. finding holds for distilled spirits, wine and beer and in almost every state in the Union. The pattern of increase has also resulted in an increase in the volume of absolute alcohol consumed per capita of the drinking age population. It is estimated that during 1947 the per capita consumption of absolute alcohol for the drinking age population was 2.03 gallons. During 1975 it was 2.69 gallons (Keller and Gurioli 1976). In Table 4-1, below. the figures show that in 1947. over half of the absolute alcohol consumed in the U .S. has ingested through beer drinking. The 1975 figures show that distilled spirits and wine are now in relatively more frequent use as sources of absolute alcohol. Because not every member of the drinking age population drinks, the average quantity of abso- lute alcohol consumed by the drinking (as opposed to drinking age) population is no doubt higher than these figirres reflect. TABLE 4-1 Apptrront ('onsrrrnption clf'Ahsol/rtr Alt,ohol in tkc United Stutes" 7)/11' of' -- Atrnrrcrl f'or C'upitu Consrrmption" YP~II. B(,\,c,rogc' G(r/lon \ Litrps % of All 1947 Spirits .76 2.88 37.4 Beer 16 .6 1 7.9 Winc 1.11 4.20 54.7 ,411 2.03 7.69 100.0 I975 Sp~rits 1.11 4.20 41.3 Beer .3? I .?I 11.9 W~ne 1.26 4.77 46.8 -- All -- 2.69 10.18 100.0 a. Soulxe of data: Keller ;~nd I976 b. B:i.;ed on drinking-age population (15 year\ old and over). TABLE 4-2 Apptrront Consumption c!f'Absol~ltc~ in tho United St(lf~s Otl~er Countries" Annrlrrl Per Cupitu Spir~t\ Peru Portugal U.S.A. Wine Portugal I974 Peru 1970 U.S:A. 197.5 Beer Belgium Spain U.S.A. All Portugal 1.974 Israel 1974 U.S.A. 197.5 - Highest l.owest 5th Highest Lowest 19th Highest Lowest 12th Highest 23.43 Lowest 3.25 16th 10.48 a. Soul.ce of data: Keller and Guriuli 1976. b. Ranking among 26 countrieh with respect tu annual per capita consumption of absolute alcohol in indicated beverage. c. Based on drinking-age population (I5 years old and over). PEOPLE WHO DRINK AKl) L)Hl\'E TABLE 4-3 Ratios qf' Apparent Annurrl Prr Cnpitu Con.v~imption Abso/ute Alcohol in Selected Countriesa Wine Beer 21. SOIII.!.~ of' data: Kcller ant1 (iurioli 1976. b. Ranking among 26) c.ount1.i~~ 1.e5pe;t lo irnnual per capita cunsump!iun of alcohol in indicated jIC", ,t , 1'1ge. C. Ba~ed drinking-age population (1.5 ),c;11,5 oltl ;inrl over!. Keller and Gurioli (1976) present data showing apparent consumption of absolute alcohol. per capita of populittion aged 15 years and over, for 26 selected countries. .4lmost all of these coi~ntr.ies Western and most of them are industrialized. In Tables 4-2 and 4-3, comparative data are shown for the U.S.A., the highest ranking country, and the lowest ranking country for each type of alcoholic beverage and for all alcoholic beverages. The fig~~res show that the drinking-age population in first-ranking Portugal consumes mow than twice as much absolute alcohol as the drinking age popu- lation of the U.S.A.; uhile the U.S.A.'s drinking age population consume5 more than th:..:: times as much absolute alcohol as the drinking age population of least-ranking Israel. The corresponding ratio for t'ortugiil itnd Israel is about seven to one. In the 17 of the 20 cour.'i.irs for which historical data were available, Keller and Gurioli (1976) found an inc~.case in the apparent per capita consumption of absolute alcohol over the time period beginning roughly in the mid-1930s to the early 1970s. The increases ranged from 20% Lor Switzerland to 170.9% for the Netherlands. The increase for the U.S.A, during this time period was 41.5%. 4.1.2 Puttoms of Corr.s~~mptiot~ l(~oltolic* Patterns of alcohol consumption in the U.S.A. vary among members of the drinking age population on the basis of a number of socio-cultural variables which appear to influence the reasons why people drink. the types and amounts of beverages they consume, and the settings in which the drinking occurs. Using data collected in a national survey conducted in 1964-1965. of the drinking patterns of adults (21 years and ALC'OHOL AND HIGHWAY SAFETY I978 older), Cahalan and associates (Cahalan, Cisin, and Crossley 1969) classified respon- dents into the following types of drinkers: heavy (12% of all respondents), moderate (13%). light (213%). infrequent (15%). and abstainers (32%). The data used to classify respondents described the quantity and type of alcoholic beverage consumed and the frequency of consumption of any type of alcoholic bever- age. Because the data collected were in the form of self-reports of respondents, quantity of consumption was defined, not as absolute alcohol content, but as number of drinks, whether mixed or straight. Quantity of alcoholic beverages consumed was measured by the average number of drinks consumed per occasion and by the frequency and amount by which this average was exceeded, i.e.. the variability of consumption. This system of classification lumps together people with quite disparate patterns of alcohol consumption. For example, the range of respondents classified as heavy drinkers includes both those who consume any type of alcoholic beverage three or more times a day and those who may drink only two or three times a month but consume five or six drinks during those occasions. The researchers on the Cahalan study note that a more adequate index of relative drinking behavior would more exactly measure the spacing or bunching of consumption of alcoholic beverages over time and would result in a more sensitive index of drinking behavior than an index based only on frequency and quantity of drinking (Cahalan. Cisin, and Crossley 1969). The findings of the Cahalan study and of more recent studies reveal that men and young adults drink in greater quantity and more frequently than women and older people: that among both men and women, the higher the socio-economic status the more likely they are to drink moderately and the more likely they are to drink heavily; that city dwellers drink more than residents of rural settings; and that the higher the level of education, the greater the proportion of heavy drinkers. Studies of drinking behavior among I talian. Irish, and Jewish groups reveal that social customs influence the type of alcoholic beverage usually consumed, the frequency and quantify of con- sumption, and the occasions on which drinking occurs. Most Americans usually drink in their own homes or in the homes of friends. They drink more when with friends on informal occasions than when with neighbors or colleagues on more formal occasions. The types of drinkers identified in the national survey described above were defined in strictly behavioral terms, i.e.. the amount and frequency of alcohol consumption. However. many researchers have found this type of definition to have limited useful- ness because it does not include information about the setting in which drinking occurs and about the social. psychological and physiological consequences of different drinkins patterns. This is especially true for researchers associated with social action programs which require the identification of target groups whose drinking patterns have been defined as problematic. Thest: researchers have been concerned with defining drinking behavior in terms of the social and psychological functions it serves. Researchers have been unable to reach agreement on functional definitions of significant types of drinkers and drinking patterns. Thus, there are many definitions in current use in the literature on the effects of alcohol on human behavior. Three catego- ries of drinkers are commonly of concern to researchers: the social drinker, the problem drinker, and the alcoholic. Social drinkers and problem drinkers tend to be seen as mutually exclusive categories at a given point in time. However, a single individual may PEOPLE WHO DRINK AND DRIVE be a problem drinker at one time in his life and a social drinker at other times. 'There is considerable overlap between the problem drinker and alcoholic categories. Not every problem drinker is an alcoholic, but the alcoholic is certainly a problem drinker. As presented below, the definitions of social drinkers, problem drinkers, and alcoholic illustrate what is commonly meant by the terms (Joscelyn and Jones 1971). "Social drinkers" are those whose consumption of alcohol is part of their socially defined interactions ~ith friends, neighbors, and co-workers. For the social drinker, use of alcohol enhances the occasions associated with it. Alcohol consumption in this context is both a symbol of chared feeling and. for some, a means of relaxingjust enough to be comfortable in sharing feeling. The health and social functioning of the social drinker are not impaired by his pattern of alcohol consumption. "Problem drinkers" is a term used to describe those whose pattern of alcohol con- sumption either contributes to or is symptomatic of the disruption of their relationships with family, friends, neighbors. and co-workers. Alcohol has not been identified as a cause of the problems of the drinkers in this category. It is just one element of behavior displayed by people with interpersonal problems who also drink immoderately. The "alcoholic" is a person whose nervous system has developed a tolerance to alcohol. i.e., over a period of time more and more alcohol is required to achieve a given effect. The alcoholic is likely to drink in order to cope with social interactions. Thus, he may drink before, as well as during. the party or ceremony. Yet, in spite of his priming, he fails to cope because he cannot control his drinking. He is unable to act upon evidence that he has reached a point in his consumption of alcohol at which the benefits of drinking begin rapidly to decline and drinking itself becomes a problem. For the alcoholic. however, in contrast to the problem drinker, drinking is not just one of an array of problems. The drinking patterns of alcoholics clearly contribute to problems of poor health, social disruption, and economic instability. 4.2 CHARACTERISTICS OF DRINKING DRIVERS The objective of this section of the report is to define in more detail, the nature of dl'l~king drivers and drinking-driving as a precursor to the discussion, in Sections 5.0 and 6.0, of methods for dealing with the problem. The material presented here consti- tutes the last step of the folJi,-step problem definition process described at the beginning of Section 2.0, i.e.: estimation of the number of crashes nationwide involving alcohol. determination of the involvement of drinking drivers in crashes relative to that of drivers as a whole. determination of whether any over-representation of drinking drivers among crashed drivers is due to alcohol. and further definition of drinking drivers and drinking-driving to support the develop- ment of methods for dealing with the problem. Researchers contributing to the literature on alcohol and highway safety have gener- ated a number of ways of categorizing variables for describing drinking drivers. Among these. the three categories i~sed by Perrine in his recent review (Perrine 1975) appear to be the most useful for describing the results of epidemiologic research, and will be adopted here. The first category cont~~ins that ase primarily hiog~.trp/lic.trl, including such d~mog~.i~phic us sex, age. race. etc. The second category is composed of tl~.i~ti~l~<~ such as n~~mber previous crashes, driving experience, amount of driving. inicsactions with law enforcement agencies. etc. The third category contains \,arinbles most descriptive of an individui~l's dr.inkirt~ practices, for example, quantity and frequency of intake. and type of beverage consumed. In addition. a foi~rth category of variables which have been analyzed in various psychometric st~~dies st~~dies surveys and tests have been used to measure certain psychologicill vitsiables) will be examined below. These variables are classified here ;IS pol..vontrlity irnd .st~~o.\.s Interactions between the above four categories of vasiables selative to drinking-driving are also discussed in this section (for example, ~~lcohol-related involvement of male problem drinkers who have been arrested for driving while intoxicated). Ide~~lly. woi~ld like to know two things about sub-g~,oups of drinking drivers described by these foils ciitegories of variables: ( I) the extent to which each si~b-groupcontributes the total alcohol-crash problem. (3) The :~lcohol-csash rsk (i.e.. selative probability of a crash after drinking) of each sub-group. The tis\t piece of informiltion requires statistics on the BACs of c,rtr.sh-in~qollred drivers broken do~n sufficient detail to descsibe the contribution of each variable. For example. if one wishes to detcsniine selative contributions of male drivers and female drivers to the alcohol-crash problem. then data giving the BACs ofmulrs and the BACs of ,fi~r?~trlc.s in crashes are required. Even then, such epidemiologic evidence will. as pointed out in section 2.1, be insufficient to "prove" that alcohol caused the crashes associated with any level of BAC. Behavioral studies showing the extent to which csitical driving tasks of each sub-group (for example, males and females) were degraded at each BAC would be needed to reinforce the epidemiologic data. The second piece of information (i.e., alcohol-crash risk of each sub-group) requires an additional set of statistics. the BACs of rrorlc4rns/l-inl~ol~jc~d in each sub-group. For example, to determine the alcohol-crash risk of males relative to that of females at any BAC would require roadside survey data showing percentages of male drivers arid female drivers with that BAC using the road at times and places of the crashes. In other wordj. controlled studies in sufficient detail to permit break-down of the data by sub- group would be needed. It will be seen in this section that w number of reliable epidemiologic studies can provide useful data for answering questions about the contributions of various sub- groups of drivers to the alcohol-crash problem, but that there are few controlled studies for determining the alcohol-crash risk of such drivers. In the literature, two approaches are often followed when data from controlled studies are insufficient to estimate the alcohol-crash risk of a particular sub-group of drivers. PEOPLE WHO DRINK AND DRIVE First, and most commonly. the incidence of the sub-group (or trait) among drivers in alcohol-related crashes (i.e., where drivers had been drinking) is compared to the inci- dence found among drivers in non-alcohol-related crashes or in all crashes. A second approach is to compare the incidence of the trait among drinking drivers using the roads with the incidence among non-drinking di.ive1.s using the roads. Clearly, neither of these two approaches can replace the controlled study for estimating alcohol-crash risk. Their findings can be helpful in making subjective judgments about risk, but they will never be sufficient for making explicit quantitative statements about relative probability of a crash after drinking. Moreover, even controlled studies will not provide an adequate basis for societal action against the individual, but can only be used for screening more specific target groups from the general population. Considerable care is required in interpreting the findings of studies of the characteris- tics of individuals who drink and drive. The reader is alerted to two pitfalls that are common in such interpretations. First, it is sometimes assumed that the finding that a given characteristic is associated with a higher than average alcohol-crash risk means that all individuals possessing that characteristic are high-risk drivers. A second pitfall is the assumption that different characteristics that have been found to be associated with increased alcohol-crash risk can be combined to form a composite picture of a high-risk driver and that all individuals matching that profile are high-risk drivers. Both pitfalls are to be avoided since they will lead to erroneous conclusions. No characteristic or combination of characteristics can safely be used to identify a given individual as a certain alcohol-crash threat, but can only be used for identifying the alcohol-crash risk of entire groups of drivers. Moreover, the usefulness of simplistic "profiles" for underscoring common characteristics of high-risk drivers can be out- weighed by the danger that such a profile may erroneously be assumed to describe the highest risk group of drivers as priority targets for countermeasures. In the following discussion of variables that have been used to describe drinking drivers, data on crash involvement are presented first (when available) to estimate the importance of the variable to the overall alcohol-crash problem, and to get a rough idea of the alcohol-crash risk associated with that variable. Next, available data on drivers using the road but not involved in crashes (i.e., data from roadside surveys) are pre- s~nted further refine the initial subjective estimate of alcohol-crash risk. Lastly, any data from controlled studies are provided as a final basis for assessing alcohol-crash risk. 4.2.1.1 Sex. Past research has consistently shown that males are highly overrepre- sented in drinking-driving populations, as well as among crash-involved drivers who have not been drinking. For example, the National Safety Council (1976) estimates that in 1975, some 55% of all registered drivers were male, but that 83% of drivers in fatal accidents were male. Similarly, 70% of drivers in all accidents were said to be male. The previously cited studies in California (Waller et al. 1970) and Wayne County, Michigan (Filkins et al. 1970) showed even greater percentages of males in crashes in which the drivers were fatally injured-86% and 9095, respectively. Those two studies ALSOHOL AND HIGHWAY SAFETY 1978 also found that about 90% of fatally injured drivers who had been drinking were males, compared to 8 1-8892 of those who had not been drinking. Similar results have been reported in studies of less serious crashes. For example, the Huntsville study of personal injury crashes (Farris. Malone, and Lilliefors 1976) found that 63% of all drivers in such crashes were male and 81% of all crashed drinking drivers were male. The Grand Rapids study of crashes of all types (most of which were of the less serious "property damage" variety) showed 78% of its drivers to be male and 8854 of its drinhing drivers to be male (Borkenstein et al. 1964). Roadde surveys conducted in controlled and noncontrolled studies have shown a predominance of males among both drinking and nondrinking drivers (Table 4-4). The Vermont study found that 79% of its control group of noncrashed drivers were male and 83% of those with BACs exceeding .lo% w/v were male (Perrine, Waller, and Harris 197 1 ). The Grand Rapids survey and combined results of the National Roadside Survey and the ASAP surveys showed almost identical percentages of males at BACs ap- proaching zero. but much higher percentages of males among drivers whose BACs were .OW wlv or above (Borkenstein et al. 1964; Wolfe 1975). TABLE 4-4 Porc.ct~tcrgc~ trmotrg Lolit-BAC und High-BAC Drivers in Roadside Surveys - - -- S11ri it\ BA C - - Nrguti\te 2 .lo% kt /v -. - - - -- Vermont (Perr~ne. and Harr~s 1971) 79' 83 Huntjv~lle (Farr~s. and L~ll~ctors 71' - Grand Rnp~df (Borken\tt.~n et al 1964) 78 05' Nat~on'll Roads~de Survey 79' 91 & ASAP (Wolfe 1975) -- -- - 'BAC < .O2C/; 'BAC < .03% "BAC < .OW 'BAC 3 ,089 None of the ~tudies cited above (or others which have investigated this varia )le) found any evidence to suggest that the reason for the higher incidence of male drivers in alcohol-related crashes was that males were somehow poorer drivers after drinking than females. On the contrary. data from the Grand Rapids study indicate the opposite may be true. Seventy-eight per cent of the study's crash-involved drivers were male, whereas 79% of its drivers using the road at the times and places of the crashes were male. At BACs exceeding .OH% wlv, the study found that 88% of the crash-involved drivers were male, compared to 95% male for the controls. The over-involvement of females at the higher BACs is further indicated by their higher relative probability of involvement during the Grand Rapids study. The data show that a male's crash risk at a BAC of .08% wlv was about twice his crash risk at zero BAC (Figure 4-1). The relative crash probability of females at a BAC of .O8% wlv was nine, or about 4Xtimes as high PEOPLE WHO DRINK AND DRIVE Figure 4-1. Relative probability of crash involvement of drivers, by sex, at given BAC levels MALE DRIVERS FEMALE DRIVERS BAC (% WIV) 12- P J: * lo, Q d 'd < Z - I I I I I I I I I I b Z W 8- E > f 5 6, 5 ). POINTS CALCULATED FROM t: c) GRAND RAPIDS DATA (Borkenstein et al 1%4) - m USING BAYES' RULE Q 4- 2 n. W > F: < W 2, d 0, 1 I I 0 I .04 1 .08 I2 16 .20 AL('OHO1. AiVl) HIGHWAY SAFETY 1978 as that calculated for males. The tigu're indicates that there was little difference between the relative probability of crash involvement of males and females at the lower BACs. and that. if anything, females experienced slightly less risk at such BACs. A recent study of nighttime drivers (Carlson 1972) found drinking females to be more frequently involved in crashes than drinking males, even at the lower BACs, and suggested that . inexperience with drinking may have been the cause. In short. research shows that there are far more male drivers involved in alcohol- related crashes than female drivers. This is due more to the fact that the men drive more than women (especially after drinking), than to any inherent difference between sexes in tole~xnce to alcohol. 4.2.1.2 .4gc. Many studies have investigated the effect of a driver's age on his chances of being involved in :in alcohol-related crash. The studies have consistently found that different age groups face different risks of such crashes. For example, in the study by Waller et al. (1970) of fatal crashes in California, 49% of fatally injured drivers under age 20 had been drinking, compared to 61% of those over 20. In the same study "only" 18% of fatally injured drivers under age 20 were legally intoxicated by today's standards (BAC 2 .lo% wlv), but 50% of those killed who were over 20 were intoxi- cated. The study also found that the percentage of fatally injured drivers over 60 years old who had been drinking and the percentage of such drivers who were legally intoxi- cated w1.e both considerably less than the corresponding percentage of drivers lrnder 60 yeqrs of age. These findings have been repeated again and again to various degrees in studies of all types of crashes (Borkenstein et al. 1964; Cosper and Mozersky 1968: Farris. Malone, and lailliefors 1976: Filkins et :\I. 1970: Perrine, Waller, and Harris 1971). All,of the more carefully designed and conducted studies have found the youngest and the oldest crash-involved drivers less likely to have been drinking or legally drunk than crash-in- volved drivers as a whole. Of course, the less severe the crash, the less likely it is that a given driver of any age will have been drinking or intoxicated. Studies of drivers not involved in crashes (i.e., roadside surveys) have observed the same genesal trend with regard to age. but the differences are usually more exaggerated. For example, the Vermont stirdy of drivers surveyed at times and places of fatal crashes found that 957 of drivers under 20 years of age had been drinking, compared to 14% of drivers who were older than 20. Of drivers under 20. 1.6% were legally intoxica~zd. compared to 2.257 of drivers over 20 (Perrine, Waller, and Harris 1971). The Huntsviile study of drivers using the roads at times and places of injury crashes found that about 45? of its under-20 drivers had been drinking (BAC 2 .03% wlv) but 11% of its over-20 drivers had been drinking (Farris. Malone, and Lilliefors 1976). The combined results of the National Roadside Survey and the ASAP nighttime surveys showed 6% of its under-20 drivers had BACs of :it least .05% wlv compared to 14% of drivers over the age of 20 (Wolfe 1975). Similar results with regard to drivers over 60 years of age were obtained in all of the above studies, i.e., older drivers were less likely to have been drinking than drivers as a whole (Farris. Malone, and Lilliefors 1976; Waller et al. 1970; Wolfe 1975). A totally different and unexpected finding resu Its from examination qf the probability PEOPLE WHO DRINK AND DRIC'E t'ig111.e 4-2 Relative probability of c~.ash involvement for drivers, by age NOTE: RELATIVE' PROBABILITY OF INVOL.VEMENT EQLALS 1.0 AT A BAC OF ZERO. + HUNTSVILLE (Farr~a. and L~ll~efors (BAC 3 .03"r WIC') I 0 GRAND RAPIDS (Borkenstein el al. 1%4) (BAC b . lOClc WIV) 0 I I 1 1 1 I I 1 I 1 < 18 18-19 20-24 25-34 35-44 45-54 55-64 65-69 70-74 375 AGE OF DRIVER AI.('OtiOI. AND HIGH WA Y SAFETY 1978 of a crash for drinking drivers rrlati~~~ for nondrinking drivers. Data from the Huntsville study (Farris, Malone. and Lilliefors 1976) and the Grand Rapids study (Borkenstein et al. 1964) indicate that crash risk of very young drivers is much higher after drinking than it is for drivers from other age groups (Figure 4-2). However, no increase in relative crash probability is noted for the oldest age groups except at the higher BACs. The usual reason given in the literature for the higher alcohol-crash risk faced by young drinking drivers is their relative inexperience with driving after drinking (Cnrlson 1972; Organization for Economic Cooperation and Development 1975; Voas 1974b; Zylman I972b), but there are few behavioral data on the differential effects of alcohol on various age groups to support this conclusion. Thu~. show that the youngest and oldest crash-involved drivers are less likely to have been drinking. However, when younger persons do mix drinking and driving, their risk of :I crash is higher than that of drivers as a whole. Older drivers have a higher crash risk at higller BAC.s than most other age-groups of drivers with similar BACs. In view of the epidemiologic evidence of the increased crash risk faced by young drinking drivers, it might be expected that the recent lowering of the legal drinking age in some states would be accompanied by an increase in the number of alcohol-related crashes involving young drivers in those states. Analyses of alcohol-related crashes in several states indicate that, indeed, such an effect does exist but leave some question as to the amount of the effect (Douglas. Filkins, and Clark 1974: Whitehead et al. 1975; Zylman 1976b; Smart and Schmidt 1976; Ferreira and Sicherman 1976; Douglass and Freedman 1977). 4.2.1.3 Mtrrittrl Srtrtr~.~. of alcohol involvement in fatal crashes have consis- tently shown that divorced or separated drivers who were fatally injured in such crashes were more likely to have bcen drinking or legally intoxicated than married, single. or widowed drivers. For example. the Wayne County, Michigan study of 309 fatally in- jured drivers found 87% of its divorced or separated drivers had been drinking and 73% si~rpassed legal standards of intoxication (BAC 2 .lo% wlv) (Filkins et al. 1970). By comparison. 71% of fatally injured single drivers had been drinking and 49% had BACs of . l0V wlv or higher. The California study by Waller et al, reported a similar trend (Waller et al. 1970). Although these findings indicate that divorced or separated fatally injured drivers are more likely to have been drinking than other fatally injured drivers, this group makes up a relatively small percentage of (111 fatally injured drivers. Less than 13% of the fatailv injured drinking drivers in the Wayne County study were divorced or separated com- pared to 34% who were single and 52% who were married (Filkins et al. 1970). In the California study, 17% were divorced or separated, 16% were single, and 61% were married (Waller et al. 1970). The Vermont study found that out of 18 fatally injured drivers, age 25 or older and with BACs of at least .lo% wlv, only one was "widowed, divorced. or separated," thirteen (72%) were married and four were single (Perrine, Waller. and Harris 1971). Thus, past studies indicate that married persons comprise a larger percentage of fatally injured drinking drivers than persons of other marital sta- tuses. At the same time, fatiilly injured married drivers are less likely to have been drinking or intoxicated than other drivers. PtOPLt WHO L)KINK AND LIRIC'E The Grand Rapids data on less serious crashes show many of the same trends noted above. Again, separated and divorced drivers in such crashes were more likely to have been drinking than drivers of any other marital status, but married drivers appeared most frequently among crashed drinking drivers (Borkenstein et al. 1964. Table 39). The Grand Rapids data also show that the marital statuslBAC characteristics of drivers using the road at times and places of nonfatal crashes were similar to those of drivers who were actually involved in such crashes. For example, 22q of such sepa- , rated and divorced drivers had been drinking, but only 11% of married drivers and 9% of single drivers had been drinking (Table 3-5n). Further. of all control drivers who had been drinking, 69% were married, 1857 were single, and 10'2 were separated or di- vorced (Table 4-5b). The data from the National Roadside SurveylASAP survey followed the same pat- terns as the Grand Rapids data, but showed fewer married drivers (51%) and more single drivers (33%) among its drinking drivers ('Table 4-Sb). This is very possibly an age effect because of the greater percentage of young drivers using the roads during the nighttime hours when the two nationwide surveys were conducted. The Grand Rapids data also showed that separated or divorced drivers with BACs of at least .OS% wiv had a slightly higher relative crash probability than married drivers who. in turn. had a slightly higher relative crash probability than single drivers (Figure 4-11. However. no significant differences between the three groups were found for drivers in the very low BAC range. All marital status groups showed essentially no increase in relative crash risk at BACs of .OIV wlv to .04% wlv. It is difficult to make strong statements about the effects of marital status alone on i~lcohol-crash risk because many of the studies which have investigated this effect have not attempted to account for interactions between marital status and age. Thus, it is iislrally not clear whether an observed difference in crash risk is due to marital status or age. Future research efforts can help remedy this problem by presenting their results so that the separate effects of the two variables can be analyzed. Certainly, research conducted to date does not prove that marital status is strongly related to alcohol-crash risk. TABLE 4-Sa Drinkiwg L)ri~,err cis tr Pcrcentrrgr c!f'Dri~lers Gi\.on Marital Statrrs Single Married Separated or Divorced Widowed 'Borkemtein et al. 1964. BAC greater than zero Cahalan 1970, BAC = .05% wlv or more Sorirc tJ Nutionti1 Roadside 5iin.e~ Grrrnd Rapid.\ tit~d < 9 I I I I I? 22 20 I? IS ALC'OtfOL AND HIGHWAY SAFETY I978 TABLE 4-5b Drir3er.s (!/'(I Girqen Maritcrl Sturus (1s u Percentuge c?f'All Drinking Drillers Notiont~l Roadside Sllrvey Grtr~lil Rirpid.5 and ASAP** -- -- - I X 3 3 69 5 1 10 14 3 2 - -. Rorkcnstc~n et ;\I. 1964. BAC' gl.c~~tcl. 1c1.o h'olt'c 1975. BAC = .05C4 wlv or rnorc Figure 4-3. Relative probability of crash involvement for drinking drivers by marital status GRAND RAPIDS DATA (Borkenstein et al. 1964) - +-t BAC = .018-.04% t 0 t 1 I SING1.E MARRIED SEPARATED OR DIVORCED MARITAL STATUS OF DRIVER 4.2.1.4 Oc.c,~iptrtiot~tii irlld Rat-(1. The Grand Rapids study provides the largest data base with which to study the effects of a driver's occupation and race on drinking- driving. An analysis of these data conducted by Zylman in 1972 (Zylman 1972a) found that drivers engaged in low stat~ls made up more than 51% of the drivers on the road with BACS of .OW wlv or higher. but less than 33% of all drivers on the road were in such occupations. The National Roadside SurveyIASAP Surveys of nighttime drivers $hob a similar trend: 69% of its drivers with BACs of .Iw wlv or higher were classified as blue collar workers. compared to 56% blue collar workers among all drivers PEOPLE WHO DRINK AND DRIVE stopped (Wolfe 1975). NRSIASAP data also show a larger percentage of black drivers in the high BAC group than in the group containing all drivers (15% vs. 11%). Non-white drivers of low status were particularly overrepresented among the high BAC members of the Grand Rapids control group. Low status non-whites represented less than 5% of all drivers in the control group but were 21% of control group drivers with BACs of at least .11% wlv. Also. non-whites were found to represent about 9% of all crash- involved drivers but were more than 27% of crash-involved drivers with BACs of. 15% (Borkenstein et al. 1964). The Grand Rapids data also show that the relative probability of a crash increased with BAC for all occupation statuses and races studied (Figures 4-4 and 4-5). The data do suggest that at low BACs non-whites may face a higher crash risk than whites but that the opposite may be true at high BACs. Occupational variables are closely related to age and sex, so that it is difficult to measure the extent to which the effects noted above are due to occupational status alone. The Vermont study attempted to separate these effects by limiting its analysis of occupation to control group males aged 25 to 59 (Perrine. Waller, and Harris 1971). The study found no significant difference in proportions of persons with given BACs by occupational level. All in all, there is no epidemiologic evidence of a strong relationship betwecn occupational statuslrace and alcohol-crash risk. 4.2.1.5 Educ-ution. The Grand Rapids study also collected data on the years ofeduca- tion of drivers involved in crashes and drivers using the road at times and places of crashes. The data showed that 37% (of all control group drivers (i.e., those not involved in crashes) had not completed high school but that 49% of control group drivers with BACs of at least .05% wlv had not completed high school (Borkenstein et al. 1964). The effect was reversed for drivers having more years of education. Persons who had completed high school or college were less frequent among drivers with BACs of .05% wlv or higher than among the driving population as a whole. A similar effect was found for the Grand Rapids drivers who had crashed. In addition, there was a higher percentage of the least educated drivers among the crash- involved population than among the control group drivers. This difference between the crash-involved and control groups also held true when only drinking drivers were examined. Other studies, however. ti't~s failed to show these trends so consistently. The Ver- mont study found no significant difference at all between drinking drivers and nondrink- ing drivers with respect to education (Perrine, Waller. and Harris 1971). The Huntsville study data showed that the least educated of its drivers were found more frequently among control group drivers who had been drinking, but indicated no difference in this respect among drivers who had crashed (Farris, Malone, and Lilliefors 1976). The National Roadside SurveyIASAP Survey of nighttime drivers found no great differences in educational backgrounds between drivers as a whole and drivers who had been drinking, but observed considerable differences when drivers with very high BACs (i.e., 3 .15% w/v) were compared to the group containing all drivers (Wolfe 1975). Again, it was found that the least educated drivers were more frequently represented in the drinking group (see Figure 4-6). ALCOHOL AND HIGHWAY SAFETY 1978 Figure 4-4. Relative probability of crash involvement for drinking drivers, by occupational level, at given BAC levels 6 r I 1 I I I 5 I 1 I I I 4, GRAND RAPIDS DATA (Borkenstein et al. 1%4) 0; 1 I 1 I I 0 .02+ .04+ .M+ .08+ .lo+ BAC. 9 WIV PEOPLE WHO DRINK AND DRIVE Figure levels 4-5. Relative probability of crash involvement for drinking drivers by race, 0 WHITE NON-WHITE GRAND RAPIDS DATA (Borkrn\tein ct al. 1964) 4, at given BAC 0 02 + .04+ .06+ .OR+ .I O+ B AC. '4 WIV Figure 4-6. Comparison of drivers with high BACs (. 15% wlv or more) with all drivers tested, by years of education IIRIVERS TESTED WITH BAC 3 15'; WIV ALL DRIVERS TFSTED DATA FROM NATlONAl ROADSIDE SURVEY AND ASAPS (Wolfe 1975) 0 I I I . - 4 -0 9 > - 0 > C . - , 5 s L. z s '* 3 9 M s + C 9 ? !2 !2 4 2 3 M . - !A 1 1 I I 1 z 3 9 8 0 %SO' t10 %to' NVHL t13.LV13tIE) 3V8 HLlM Stl2AltICl ClBA1OANI HSVtl3NON ti0 % Figure 4-18. Percentage of drivers who had driven a given number of miles per year: compari- sons of all drivers with drinking drivers 0 NATIONAL ROADSIDE SURVEY:ASAP: A1.L DRIVERS (Wolfe 1975) NATIONAL ROADSIDE SURVEY;ASAP: DRIVERS WITH BAC r 1W W/V (Wolfe 1975) GRAND RAPIDS ROADSIDE SURVEY: ALL DRIVERS (Borkemtein et al. 1%) GRAND RAPIDS ROADSIDE SURVEY: DRIVERS WITH BAC 2.08% WIV (Borkenstein er al. 1964) 60 - V) Czl W L 2 n L O40- & MII-ES DRIVEN PER YEAR ALCOHOL AND HIGHWAY SAFETY 1978 Figure 4-19. Percentage of drivers who had driven a given number of miles per year: comparison of crash-involved drinking drivers (BAC of -08% wlv or more) with noncrash-involved drivers Less than 1.000 1.000-5.000 5.000-IS.000 More than 15,000 ANNUAL MILEAGE L a 0 z ' 60. drivers showing nearly nine times the percentage of previously convicted drivers as the non-intoxicated drivers. Very strong relationships were also found between number of criminal convictions and BAC, and number of nondriving drunkenness convictions and BAC (Filkins et al. 1970). A ,recent study of drivers who were found to be responsible for fatal crashes in Boston noted a similar trend with respect to citations for driving under the influence of alcohol andlor for public drunkenness (Sterling-Smith 1976). Thirty-nine percent of the drivers involved in the alcohol-related crashes (BAC 2 .05% wlv) had previous cita- tions, but only 24% of the drivers in the nonalcohol-related crashes had previous citations. Of course, neither the Wayne County study nor the Boston study provides a sufficient basis (i.e., high alcohol-crash risk) for concluding that number of previous citations is somehow a causal factor in alcohol-related crashes. The findings from these and simi!..tr studies merely provide clues that must be combined with other evidence for arriving at conclusions about the importance of a trait in identifying high-risk groups. Persons who have been arrested for driving while intoxicated (DWI) or some equiva- lent offense have been the subject of considerable study as a group. One of the first of these studies was conducted in Columbus, Ohio in the early 1%0s (Shupe and Pfau 1966). The data were developed by reviewing more than 13,000 police records which described the arrestees' demographic characteristics, conditions surrounding the arrest, police officers' observations, the results of physical performance tests administered by the officers (e.g., walking, picking up coins, etc.), drinking habits, and measurements of alcohol concentration in body fluids. - 0 GROUP OF CRASH-INVOLVED DRIVERS X GROUP OF DRIVERS USING THE ROAD AT TIMES AND PLACES OF CRASHES DATA FROM GRAND RAPIDS (Borkenstein et al. 1%) 3 CJ Q W z - ;/, 40 , z W > - z n PEOPLE.' WHO DRINK AND LIRIVE Perhaps the most striking finding of the Columbus study was the common occurrence of very high BACs among the DWIs. The median BAC of the 1,450 drivers who underwent blood tests was .21% wlv, and 97% of the blood specimens yielded BACs of .lo% w/v or higher. BAC estimates from the results of 8.500 urine analyses were in general agreement with the direct measurements of BAC (Shupe and Pfau 1966). These findings suggest that enforcement action tends to be directed at drivers who are very intoxicated and applied less often to drivers who are less intoxicated but still impaired. The Columbus study found its DWIs to be predominantly male (95.4%) and white (76.7%). Non-whites, however. were overrepresented, with an arrest rate almost double' that of their incidence in the general population of Columbus at the time of the study. The median age group of the DWIs was 35 to 39 years, and nearly 17% of all DWIs were over 50 years of age. By contrast, only 0.2% were under 18 and less than I% were under 20 (Shupe and Pfau 1966). The days of the week and the times of day of DWI arrests in Columbus followed a pattern observed in other studies of drinking drivers who had crashed and in studies of drinking drivers selected at random from the traffic stream. Weekend, nighttime arrests were again the most frequent. Saturday arrests were more than twice as frequent as arrests on all other days. and the arrest rate during the hours of 8:00 p.m. to 4:00 a.m. was nearly three times that for the hours of 4:00 a.m. to 8:00 p.m. (Shupe and Pfau 1 966). Two studies have compared groups of DWls with other groups of drivers. The first (reported in 1970) analyzed the driving records of a group of 169 Detroit drivers con- victed of DUIL or DWI, and the records of 134 drivers killed in Detroit crashes (Filkins et al. 1970). The crash-involved drivers were further segregated into a "high BAC" group (BAC 2 .IS% wlv) and a "low BAC" group (BAC < .IS% wlv) for purposes of comparison. The Detroit study found that all three groups were predominantly male. The DWI group contained 98% males. The average age of the high-BAC fatality group was 36 years, compared to 44 years for the DWls. The fatally injured drivers with high BACs and the DWIs had an almost identical average number of driving violation convictions in the previous 6-112 years (about 5.5 per driver). However. fatalities with low BACs had fewer convictions (3.7 per driver) than either of the other groups. Fatally injured drivers with high BACs and DWls were also closely matched with respect to number of prior convictions for DWI, but fatally injured drivers with low BACs had many fewer DWI convictions than drivers in the other two groups. Both the high-BAC fatalities and the low-BAC fatalities had more prior speeding convictions on the average than DWIs, and the high-BAC fatalities had the highest number of such incidents. Finally, the average DWI had far more prior crashes than drivers from either of the other two groups (Filkins et al. 1970). The second comparative analysis of DWIs (reported in 1971) was conducted as a part of the Vermont study (Perrine. Waller, and Harris 1971). It found that DWIs are nearly al- ways male (98%). that most DWIs are in the 25 to 59 age group (median age 36 years), that DWls are more likely to have a low-status occupation than any other type of occupation. and that the Vermont DWI was far more likely to have been arrested on Friday, Satur- day, or Sunday than on any other day of the week. Nearly half of all arrests occurred on ALC'OHOL AND HIGHWAY SAFETY 1978 Friday and Saturday nights. As in Columbus, BACs were extremely high among the DWIs. Only one out of the 103 tested had a BAC of less than .lo% wlv, and more than one-half of the DWls had BACs of over .20% wlv (Perrine, Waller, and Harris 1971). After comparing its DWls with the other drivers, the Vermont study found that the DWls were far more likely to have had a previous citation for a traffic law violation than either fatally injured drivers or drivers using the roads at times and places of fatal crashes. However. DWls and drivers using the road did not differ significantly with respect to number of prior crashes reported (Perrine, Waller, and Harris 1971). The above-cited studies suggest. but do not prove, that drivers with prior convictions (particularly, convictions for DWI) may, as a group. have a higher alcohol-crash risk than drivers as a whole. Any stronger statement about the alcohol-crash risk of drivers with prior convictions would require reliable data from controlled studies, and such data do not exist at present. A number of studies have examined various variables which describe an individual's drinking patterns and have attempted to develop relationships between such variables and the biographical and driving variables discussed in the two preceding sections of this report. Data on drinking patterns have been derived entirely from questionnaires admin- istered in various types of interview situations, e.g.. to persons stopped during roadside surveys. to DWls identified during record searches and later contacted by interviewers, to persons being treated for alcoholism in hospitals, and to survivors of persons killed in crashes. The accuracy of such reports is, therefore, dependent on the ability of an individual to recall information and his willingness to report it accurately if it is recalled. The information sought is frequently of a highly sensitive nature (e.g.. alcohol prob- lems. fqequency of driving while intoxicated) which may create a tendency anong re- spondents to conceal 01. distort their true habits. Thus, to have any chance of obtaining scientifically meaningful data, studies on drinking patterns relative to drinking-driving must be carefully designed and executed. The skill of the interviewer is often crucial in eliciting valid responses. Most studies have not provided detailed descriptions of their research procedures, so that it is not possible to provide an assessment of them here. The reader should keep in mind the inherent limitations of research on drinking patterns when reviewing the material presented below. 4.2.3.1 F~+ec/rrrnc-y Qrrlrntit.v of'DrinXing. The Grand Rapids study was the first in this country to attempt to collect hard data on drinking habits directly from crash- involved drivers and drivers using the roads at times and places of the crashes. The data indicated that the crash-involved drivers tended to drink less frequently than the drivers who had not been involved in crashes (Table 4-6). However, the BACs of the crash- involved drivers were generally higher than the BACs of the noncrashed-involved drivers regardless of reported drinking frequency (Figure 4-20). An exception to this rule oc- curred for more frequent drinkers at low BACs. Individuals who said they drank at least on a weekly basis were actually underrepresented among crashed drivers when compared to noncrashed drivers. In fact, at any given BAC interval except the highest, the ratio of crashed drivers to control drivers decreased with increasing drinking freqllency. PEOPLE WHO DRINK AND DRIVE Figure 4-20. Ratio of percentage of crash-involved drivers to percentage of noncrash-involved drivers for given BAC, by self-reported drinking frequency - GRAND RAPIDS STUDY (Borkenste~n et al 1964) - BAC = .OS% - 07'7 - - - BAC = Olg - ,04% BAC = (Wr , 0 I I I I I 8 YEARLY MONTHLY WEEKLY THREEIWEEK DAILY SELF-REPORTED DRINKING FREQUENCY ALC'OtiOL. AND HlGtf WA Y SAFETY 1978 TABLE 4-6 A17rrrig~ Fri-'y~~enty by Crush-ln\~olved Drivers and Drivers Using the Road Idlrtu from Grontl Rupids [Borkrnsrcin cJt al. 19641) < li!etrl 1 I\ o(11 lIr?rot~tll 1/11 rrk 31n oek Darlj hon-C lash 25 7 14 X I5 I 22.9 11.2 10.4 CI :is h 29.0 IS 7 17.7 22 6 9.0 6.0 A group's crash probability. given some value of BAC. relative to the group's crash probability given a zero BAC, can also be calci~lated from the Grand Rapids data as a function of drinking frequency. The results show that at moderate BACs (.05-.07% wlv). the Grand Rapids drivers who drank more frequently faced a much lower relative crash risk than infrequent drinkers (Figure 4-21). In other words, moderate amounts of alcohol seemed to be less risky for these apparently more experienced drinkers. Fur- ther. the reli~tive crash probability for the least frequent drinkers turns out to be quite high eben at moderate BACs. An interesting trend can also be observed for the daily drinkers, who had a higher crash risk ;it the higher BACs (.08-. 10% wlv and 2 ,1057 wlv) than individuals who said they drank three times a week. In any case, a positive BAC increased the probability of a crash. regardless of drinking frequency. Hurst has also calculated the relative probability of crash as a function of drinking frequency for the Grand Rapids drivers, but used a different baseline value than was used in Figbre 4-21 (Hurst 1974). He obtained a given group's probability of a crash, given some value of BAC, relative to the probability of a crash for all drivers, given a zero BAC. His results. reproduced in Figure 4-22, show that the more frequent drinker faced a lower relative crash risk at NN~ BAC than the less frequent drinkers. In fact. the crash risk of the daily drinker at a BAC of about -08% wlv was found to be approximately the same as that of drivers as a whole at zero BAC! Nevertheless, the relative risk of all drivers (including frequent drinkers) increased with increasing BAC. Further. the trends were such as to suggest the existence of very high relative risks for even the frequent drinkers at high BACs (i.e. 3 .IS% wlv). The $0-called "Grand Rapids Dip" (i.e.. relative crash probabilities of less than one in the .OI-.04% wlv range) has been explained as a drinking frequency effect. It 1s hypothesized that the drivers with low BACs were predominantly higher frequency drinkers and that these were persons who, for some reason, were safer drivers (Hurst 1974). However, a study by Allsop (1966) in 1966 found that the dip was not statistically significant (i.e., had a fairly high probability of being due to chance alone). The Vermont study used a measure called a Quantity Frequency Index (QFI) to study the effects of drinking patterns on driving. The index was based on self-reports of the usual frequency and quantity of alcohol per sitting and the beverage which was reported to have been consumed most frequently and in largest amount (Perrine, Waller, and Harris 197 I). PEOPLE WHO DRINK AND DRIVE Figure 4-21. Relative probability of crash involvement at given BAC levels for drivers, by self-reported drinking frequency SYEARLY MONTHLY WEEKLY THREEIWEEK DAILY SELF-REPORTED DRINKING FREQUENCY 14 I! I2 II lo k z 2 u 9. > > x Z - I V1 < CL CI L n 6- i t: J - m 5- d m rY 2 4, ..T > c 3, 5 I tL z 2, 1 0 ' NOTt: RELATIVE PROBABILITY OF INVOLVEMENT EQUALS 1.0 AT BAC OF ZERO , , BAC > . l Wr W!V - , DATA FROM GRAND RAPIDS STIIIIY (Borkenslein el al. 1964) HAC = .05% - ,0751 7- BAC = .08% - .10% BAC = 01% - ,049 - I 1 I 1 I ALCOHOL AND HIGHWAY SAFETY 1978 Figure 4-22. Relative probability of crash involvement. by drinking frequency subgroups, as a function of BAC BAC (rlr WIV) 10.0 8.0 h,~) 4.0 2,0 1 .o 0.8- The interrelationships of (SF1 with numerous bi~graphical and driving variables (in- cluding BACs obtained from drivers) were analyzed in the Vermont study. It was found that the proportion of male drivers increased as QFI increased. A large proportion of teenaged drivers were found to be heavy and frequent drinkers, but QFI tended to decrease with increasing age. Further, married drivers became less frequent as QFI increased. No significant differences were observed with the occupational level of the driver. but the study found some evidence that drivers with high QFls were more likely to have frequent job changes (Perrine, Waller, and Harris 1971). A very important finding of the Vermont study was that when the reported frequency of drinking-driving is high, reported drinking is heavy and relatively frequent. It was also found that when the reported frequency of drinking-driving is low, reported drink- - SI!IaI.-REPORTED URINKIN(j FREQUtNC'Y: - Y.--..**..,Y YEARLY OR LESS f ,*y - M- --M MONTHLY ./ M ,*' / - We." 3XIWEEK 8' / x- - - X WEEKLY i - OD .,*" / 0.' / - "' / .*.* , w .J' / /' SOURCE: HURST (1974) ./'; / /. i /. ,.') / - /. ..." / Y.# / W /' , C *x .., ,.. . ..('..' / 0 .I y,*,,,,,... .*''''' .// - r-----M ./- .I .I 0 __----- - ././--W W- cc4--C _ - -x- XI- CI--- n h RELATIVE PRoRABlLlTY OF CRASH INVOLVEMENT OF COMPOSITE GROUP AT ZERO ALCOHOL EQUAL TO 1.0 PEOPLE WHO DRINK AND DRIVE ing is light and relatively infrequent (Perrine. Waller, and Harris 1971). A similar trend was noted in the National Roadside SurveyIASAP Surveys (see Figure 4-23). The data in Figure 4-23 show that the heavier the reported drinking pattern, the greater the propor- tion of drinking drivers. The consistency of the findings of these two studies provides support for using BAC measurements as an indication of drinking-driving patterns. The Vermont Study found little relationship between number of crashes or number of license suspensions and QFI. However, it was found that control drivers with higher QFls tended to have more citations for traffic violations than drivers with lower QFIs. Further analyses of drivers who had been arrested for DWI showed them to have higher QFIs as a group than deceased drivers (i.e.. drivers killed in crashes), roadblock drivers (i.e.. drivers using the roads at times and places of fatal crashes), or clear-record drivers (i.e.. drivers with no previous citations for traffic violations). (See Figure 4-24.) In the Huntsville study each driver in the crash group and in the control group was asked how many drinks he normally consumes on a single occasion. No significant difference was found between the two groups with respect to percentage of drinkers, but it was found that the crash-involved drivers who drank were slightly heavier drinkers than the control group drivers who drank. The mean number of drinks per sitting for the crash group was 3.04. compared to 2.66 for the control group (Farris, Malone, and Lilliefors 1976). The Boston study of fatally injured drivers deemed responsible for their crashes found that 39% of such drivers whose crash involved alcohol had consumed alcoholic beverages daily and 38% had consumed alcohol weekly. Only 8% were abstainers. The study also compared the long-term alcohol use patterns of this group with another group of drivers whose crashes had not involved alcohol and found the latter group much less inclined toward heavy alcohol usage than the group whose crashes had involved alcohol (Sterling-Smith 1976). Unfortunately, the validity of these findings is not known, be- cause of the manner in which data on the drinking patterns of the drivers were devel- oped, i.e., through personal interviews with relatives of the deceased drivers. 4.2.3.2 Type of Br~~erugo. indicates that the preferred beverage of both crash-involved and noncrashed drivers is, by a wide margin, beer. The Grand Rapids study (Borkenstein et a]. 1964) found 61% of its drivers preferred beer over either distilled spirits (35%) or wine (4%). The crash-involved group favored beer more than did the control group (65'"- vs. 59%). Beer drinkers were 81% of control group drivers with BACs of .08% w/v or higher The Vermont study (Perrine, Waller, and Harris 1971) found a high correlation be- tween frequent and heavy use of beer and BACs of .lo% wlv or higher. Relative to fatally injured drivers with no alcohol, over twice as many deceased drivers with high BACs were said to have drunk beer daily. The same was true of control drivers, although not quite to the same extent. Among these drivers who drank beer, 67% of DWIs and 80% of fatalities with high BACs drank it daily (Perrine 1975). The more recent National Roadside Survey/ASAP Surveys (Wolfe 1975) also showed a preference for beer among nighttime drivers interviewed in its roadside surveys. Sixty-three percent of all such drivers listed beer as their most used beverage, and 73% of drivers with BACs of at least .lo% w/v preferred beer. ALCOHOL AND HIGHWAY SAFETY 1978 Figure 4-23. Percentage of drivers who classify themselves as given drinking types, with given BAC levels 60 50 C 3 2 0 40 u C >. b i; Z - V 3" - p? n Z - V1 x L > 20 - x n Li. 0 b: 10 0 BAC 2 .05% WIV DATA FROM NATIONAL ROADSIDE SURVEY AND ASAP SURVEY (Wolfe 1975) BAC a .1Wc VERY LIGHT FAIRLY MODERATE FAIRLY HEAVY LIGHT HEAVY DRINKING TYPE-SELF CLASSIFICATION PEOPLE WHO IIKINK AND DRIVE Figure 4-24. Proportion of roadblock, clear-record, DWI, and deceased drivers with light, light- medium, medium, or heavy quantity-frequency index for preferred beverage Ir -4 DECE'ASED DRIVERS ROADBLOCK DRIVERS 60 0- - - 0 CLEAR-RECORD DRIVERS 0-- --a DWl DRIVERS LIGHT LIGHT-MEDIUM MEDIUM HEAVY QUANTITY-FREQUENCY INDEX None of the studies cited above should be interpreted as showing that beer drinkers have a greater alcohol-crash risk than other drinkers. 4.2.3.3 Place of Drit~king. The Grand Rapids and the Vermont studies found that wme two-thirds of their drivers did their drinking at home (Borkenstein et al. 1964; Perrine, Waller, and Harris 1971). In Grand Rapids, a slightly larger percentage of crash-involved drivers than control drivers drank at home (65% compared to 59%). Both studies found that only 10-1 1% drank at the home of friends and relatives. The remaining 25% or so of the drivers said they usually drank at such places as public establishments, parties, etc. In Grand Rapids, the hiL:ne; BACs occurred almost entirely among drivers who drank at home or in a public establishment. Among control group drivers (i.e., noncrash- involved) who drank at pirblic establishments. 4% had BACs of -08% wlv or higher. By contrast, only 2% of all control drivers had BACs above -08% w/v (Borkenstein et al. 1 964). Neither the Vermont study nor the Grand Rapids study shows any strong, direct relationship between place of drinking and alcohol-crash risk. 4.2.3.4 Alcoholics trrtd Problem Drit~kers. General definitions of alcoholics and so- called "problem drinkers" were given in Section 4.1.2 of this report. In reviewing the multitude of definitions (c-irca 1972) of the term "alcoholic," Joscelyn and Jones (1971) concluded that: "An alcoholic is any person who: ALCOHOL AND HIGHWAY SAFETY 1978 Chronically and habitually uses alcoholic beverages to excess, Is physiologically or psychologically dependent on alcohol, Loses the power of self-control with respect to use of alcohol, To the extent that: He becomes a menace to the public morals, health, safety, or welfare of the members of society in general. His drinking frequently or continuously interferes with his business life, social life, physical or mental health, relations with the law, or causes a continuing problem in any department of his life. Who shows prodromal signs of such development." The term "problem drinker" is usually used to describe individuals with many of the same ch~tracteristics as the alcoholic, but whose drinking problems have not progressed as far as those of the alcoholic. In a study conducted in 1967 and 1969 of the problem drinking male population in the U.S.. Cahalan and Room (1974) defined 13 specific measures of drinking-related problems: (I) /lo(r\,y intclko-frequency of drinking 5 or more drinks on an occasion or of getting "high" or "tight." (2) bing~~ intoxicated for several days at a time, (3) p.vyc~hologicu1 on alcohol to change moods, (4) lo,ss of c~ontrol-inability (or impaired ability) to abstain from drinking or inabil- ity (or impaired ability) to stop once started. (5) symptomutic* drinking behavior-items drawn from classical symptomatology of Alcoholics Anonymous, such as blackouts, skipping meals whdn drinking, sneaking drinks, (6) b~~lligerence drinking-feelings of aggressiveness, crossness, getting into fights or arguments, (7) problems ~'itlz spouse--extent to which marital functioning is disrupted by drinking behavior, (8) prohlcms with relatil'es-displeasure on the part of relatives with subject's drinking behavior, (9) problems ~lith or neighbors-loss of or harm to friendships, advice from friends or neighbors to cut down on drinking, (10) job problems-loss of promotion or job because of drinking, being advised by boss or colleagues to cut down on drinking, (1 1) police problem,^ over drinking-trouble with law about drinking behavior, in- cludes contact with law when drinking and driving, ( 12) problems with health or injuries related to drinking-physicians' warning to cut down on drinking, giving up drinking for health reasons, injuries in accidents due to drinking, (1 3) finoncia1 problems related to drinking--drinking seen by subject as harmful to his financial position. PEOPLE WHO L)KIhlK AND DRIVE For each of these types of problems. the survey respondent (males aged 21-59 years) indicated whether he currently (within the three years immediately preceding the survey) had the problem and whether he had ever had it within his lifetime. The severity of the problems was also measured. Fifty percent of the survey respondents currently had at least one of the 13 problems at a minimal level of severity. Seventy-two percent of the respondents had had at least one of the problems during his lifetime at a minimal level of severity. Thirty-six percent of the respondents currently had at least one of the problems at a high level of severity, and 55% of the respondents had had at least one of the problems at a high level of severity during his lifetime. The fact that so many people have had drinking-related problems is indicative of the pervasiveness and potenrial danger of heavy drinking in the U.S., but does not imply that individuals who have experienced only one or even a few of these problems are necessarily "problem drinkers" in the usual sense of the word. There is, in fact, a general lack of precision in defining the term "problem drinker" in the field of alcohol- highway safety, and this makes it impossible to determine the role of "problem drinkers" (i.e., individuals who have significant drinking problems but are not yet alcoholics) in highway crashes. Obviously, programs to deal with such a broadly- defined group are difficult to design, and no single approach (e.g., treatment and reha- bilitation) will be appropriate for all so-called problem drinkers. More will be said about past methods of dealing with alcoholics and problem drinkers in Section 5.3. Within the field of highway safety. personal-profile instruments have been developed which are used to screen drivers for- alcohol-related problems. A recent review has been conducted of a number of these alcohol-use assessment techniques (McBride and Stroad 1975a: McBride and Stroad 1975b). A modification of the thirteen types of problems listed above was used in an analysis of the content of selected diagnostic devices. The reviewers found that the techniques reviewed used almost all of the types of problems listed above in attempting to diagnose problem drinking. An underlying assumption of these techniques is that these problem-content areas have some real, though unknown, relationship to problem driving. The most widely used of the techniques reviewed is the HSRI Protocol, also known as the Mortimer-Filkins Test (Filkins et al. 1973). The questionnaire, interview, and scoring procedure, and variations of them. which make up this technique have been used extensively in the Alcohol Safety Action Projects (ASAPs) funded during the early 1970s by the National Hibhwity Traffic Safety Administration. The arrested driver is questioned ;;bout his health; arrest and driving history; marital, family, and work his- tory; and drinking history (Kerlan et al. 1971). The questions cover many of the 13 measures of drinking-related problems described by Cahalan and Room. The protocol recommends that persons scoring less than 40 on the test be classified as social drinkers, that persons scoring 40-49 be classified as presumptive problem drinkers, and that persons scoring greater than 50 be classified as problem drinkers. In three ASAPs in which full use was made of the HSRI Protocol, it was found that about 55% of the drivers who had been apprehended for driving while impaired (DWI) could be classified as problem drinkers (Filkins et al. 1973). In validating the HSRI Protocol, the developers used a criterion measure based on the BAC level of the DWI driver at time of arrest. previous DWI arrests and number of ALCOHOL AND HIGHWAY SAFETY 1978 previous other alcohol offenses (e.g.. drunk in public [DIP]). (This criterion measure is similar to the "problems with police" category in the classification scheme used by Cahalan and Room [I9741 and described above.) The following types of drinkers were defined in validating the HSRl Protocol: (1) social drinkers-BAC less than 0.15% wlv at time of arrest and no previous DWI or DIP arrests, (2) excessive drinkers-BAC of -15-. 19% wwiv at time of arrest or one prior DWI arrest or 1-2 DIP arrests. (3) problem drinkers-BAC of .20% wlv or more at time of arrest or 2 or more prior DWI arrests or 3 or more DIP arrests or 2 of the items used to indicate excessive drinking. Use of this criterion measure resulted in the classification as problem drinkers of more than 50% of the subjects in the samples of DWls studied, compared to 55% when the HSRI Protocol and recommended scoring rules were used. Eighty-three percent of the persons classified as problem drinkers by the criterion variable would be so classified by the HSRI Protocol following recommended scoring rules (Filkins et al. 1973). Con- versely, 17% of the persons classified as problem drinkers by the criterion variable would not be so-classified by the HSRI Protocol. Thus, even the careful criteria em- ployed in the HSRI Protocol do not permit perfect consistency in classifying drivers as problem drinkers. No one knows exactly how many alcoholics and problem drinkers there are in the United States. A figure often used is 3l/2% of the drinking age population are alcoholics and another 3lIL% are problem drinkers (Efron, Keller, and Gurioli 1974; Keller 1975). The role of persons with drinking problems in crashes (both alcohol-related and nonalcohol-related) has been the subject of much study by researchers. 1ne range of views on the role of alcoholics in crashes is illustrated by the different conclusions reached by two long-time researchers in the field. Julian A. Waller and Richard Zylman. In reviewing applicable research prior to 1965, Waller (1968) observed that alcoholic drivers in particular appeared to have nearly twice as many crashes per vehicle-mile trav- eled as do nonalcoholic drivers. Waller estimated that, in California, drivers with alcohol- ism could be involved in 41%-62% of "known drinking accidents" and concluded that "the overwhelming weight of evidence is that alcoholism plays a very substantial rille, and probably the major role, in the occurrence of traffic accidents involving the use of alcohol" (Waller 1968). In arriving at these figures, Waller classified as alcoholics drivers who were known to the Department of Motor Vehicles (DMV) as alcoholics. Conversely, drivers not known to the DMV as alcoholics were classified as non-alcoholics. Zylman, on the other hand, has stated that the role of alcoholics in crashes has been exaggerated. He cautioned against branding all alcoholics as "high risk drivers" and cited studies which indicated to him that the driving records of alcoholics were not as bad as had been stated by some. He noted that many studies had suggested that other psychological and social stress factors often interact with alcoholism to create behaviors that lead to crashes and that "the misuse of alcohol is only one manifestation of deviant behavior" (Zylman 1976a). PEOPLL' WHO L)KI/VK AN/) DRIVE In some respects, there is really little disagreement between these two views. No responsible researcher has suggested that rrll alcoholics are higher risk drivers, and it is generally accepted that the excessive use of ~tlcohol per se may not be the root cause of crashes involving alcoholic drivers. (See the following section of this report for a discus- sion of psychological and personality factors relative to alcohol-involved crashes.) Past research indicates that, for whatever reason, individuals who have been identified as alcoholics are, as a group, more frequently involved in crashes and enforcement actions than nonalcoholics as a group and that alcoholics are, therefore, a logical subject for further study. At the same time, it must be recognized that past studies do not provide an adequate basis for stating conclusively that alcohol-impairment of critical driving tasks has actu- ally c~rir.vc~d given fraction of crashes involving alcoholics or problem drinkers. This uncertainty about causation is due to a lack of controlled studies of problem drinker- drivers who have crashed and problem drinker-drivers using the roads. It is further exacerbated by a lack of behavioral studies of the impairment of driving performance of alcoholics/problem drinkers relative to other types of drinkers, and by imprecise definitions of the term "problem drinker." Past studies (including those by Waller, Zylman and others cited below) have relied on other data (e.g., driver records. accident repoi-rs prepared by police officers, etc.) to provide clues or "indicators" about the involvement of alcoholics and problem drinkers in alcohol-related crashes. One such indicator that has been studied is one that physiologists associate with excessive drinking over extended periods of time-fatty degeneration of the liver. In a study of persons fatally injured in California crashes, Waller and associates found that the proportion of persons with fatty liver changes among persons who had not been drinking was 14%-153. Among those with BACs of. 15% wlv or greater, the proportion with fatty changes was 2 1%-39%. The study also found alcohol significantly more often among persons who had previous arrests or fatty liver changes than among those with normal liver and no arrests (Waller et al. 1970). In the Wayne County, Michigan, study of highway crash fatalities, 39% of persons over 25 years old with BACs loss than . IO'ii wlv had fatty livers. compared to 50% of those over 25 with BACs of -10% wlv or greater. Four percent had cirrhotic livers and one cirrhotic male. 2 1 years old. had a BAC of .26% wlv (Filkins et al. 1970). The Vermont study performed more detailed analyses of fatty degeneration of the livers of persons killed ir; highway crashes in that the degree of such changes was also noted. The study found that persons under age IS, even with alcohol in their blood, seldom had fatty changes of the liver. Among persons of age 25 or older, the presence of alcohol was associated with greater frequency and greater severity of fatty liver. The study also found that the distribution of fatty livers among highway fatalities with zero BAC was more similar to that of persons dying in the general population than to alcohol-related highway fatalities (Perrine, Waller, and Harris 1971). It is important to note that fatty changes of the liver do not in themselves provide conclusive proof of a drinking problem in individuals whose livers have undergone such changes. The phenomenon is associated with heavy drinking, but it cannot be said that all persons who drink so heavily are also problem drinkers or alcoholics. The Grand Rapids study surveyed its control group of drivers to determine if and how ALCOHOL AND HIGHWAY SAFETY 1978 BAC was related to symptoms of problem drinking. It found that persons who reported they "got high" on a weekly basis comprised 29% of drivers with BACs of .O8% wlv or greater, but were only 6% of drivers with zero BACs. Also, 21% of drivers with BACs of .08% w/v or greater said they had drinking "problems," compared to 6% of drivers with zero BAC. Similar relationships were found between reports of hangovers and blackouts and BAC (Borkenstein et al. 1964). The University of Michigan's Highway Safety Research Institute (HSRI) analyzed the medical records, group therapy records, driving records, criminal records, and death certificates of 1,517 hospital patients diagnosed by physicians as alcoholics. The study sought to characterize alcoholic drivers who were disproportionately involved in high- way crashes and to develop methods to support early identification and rehabilitation of such drivers (Filkins et al. 1970). The HSRI study found that the crash rate for the alcoholic drivers was about twice as high as the crash rate for the same age group (26-75 years) for Michigan drivers as a whole. The higher crash rates for these alcoholic drivers were associated both with younger age (less than 46 years) and with a high rate of driving convictions unrelated to crashes. Convictions for DWI were also relatively high for the alcoholics, and the crash rate of alcoholic males was about 50% higher than the crash rate of alcoholic females. The HSRI study also found evidence to support the conclusions that there was a direct correlation between high rate of driving convictions and behavioral deviancy and that behavioral instability was associated with a high crash rate (Filkins et al. 1970). In comparing the alcoholic driver with other groups of drivers, the HSRI study found that the mean number of crashes for alcoholics was similar to that for fatally injured drivers with high BACs, but higher than the mean number of crashes for drivers as a whole and for fatalities with low BACs. Drivers convicted of DWI had a crash rate about twice that of alcoholic drivers. The alcoholic drivers had the highest mean num- ber of DWI convictions among fatally injured drivers, DWIs, and drivers as a whole (Filkins et al. 1970). Finally, the recent study of fatally injured Boston drivers said to be most responsible for their crashes found that 63% of the drivers in the alcohol-involved crashes had a history of problem drinking (Sterling-Smith 1976). Only 25% of the drivers in the nonal- coho1 involved crashes had a history of problem drinking. Of the drivers with BACs of .20% w/v or greater, 72% were said to have had known alcohol problems. As was noted previously in this report, the validity of these findings is not known because of he manner in which a history of problem drinking was determined, i.e., through interviews with relatives of the deceased drivers. In summary, there is considerable evidence to indicate that persons with severe drinking problems (particularly alcoholics) are overrepresented in alcohol-related crashes, but there is insufficient scientific basis for an accurate quantitative estimate of the overrepresentation. Such an estimate cannot be developed without data from care- fully-designed controlled studies of the incidence of such problem drinkers in alcohol- related crashes and in the population of drivers using the roads at times and places of such crashes. Behavioral studies of the impairment of performance of critical driving tasks in alcoholics and severe problem drinkers are also needed to support stronger and more quantitative statements about causation. More precise definitions of the term PEOPLE WHO DRINK AND DRIVE "problem drinker" and additional research are needed to determine the role of this broad class of drivers in alcohol-related crashes. 4.2.4 Vurinhles Describing Personcl1it.v und Exposirre to Stress Personality and stress variables associated with crash-involved behavior of drivers have been relatively difficult to define and measure. Most of the research in this subject area focuses on the general driver population, but there are a number of studies which have examined the relationships between personality traits, exposure to socio-psycho- logical stress, and the crash-involved behavior of drinking drivers (McBride and Stroad lY7Sa: McBride and Stroad 1975b; Selzer and Vinokur 1974; Selzer and Vinokur 1975). In these studies, researchers have attempted either to select problem drinkers from known problem drivers or to select problem drivers from known problem drinkers. Once this initial selection was completed, the next step was to try to identify those traits of the subgroups which appear to be most related to concurrent and/or future crash involvement. Use of the psychometric diagnostic measures developed in this research has resulted in some success in detecting problem drinkers but has not proved useful in isolating high-risk drivers from samples of problem drinkers (McBride and Stroad 1975a). 'The value of these research findings is compromised by several methodological short- comings characterizing work in this field. Many of the techniques used to measure psychological traits do not have demonstrated reliability, i.e., the capability of produc- ing the same results under similar conditions on different occasions. The Mortimer- Filkins Test (or HSRI Protocol) (Filkins et al. 1973) is an exception. This most widely used of the techniques has been reported to have moderately high reliability. Nor has predictive validity, a demonstrated relationship with future driving behavior, been es- tablished for most of these tests. In addition, many of the samples used are too small to allow reliable interpretation of findings (McBride and Stroad 1975a). Two major variables describing the alcohol usage of drivers have been defined by researchers interested in personality and stress variables. One variable tests the sub- jcst's pattern of alcohol usage over an extended time period. The other variable mea- sures BAC at a given point in time-when the driver is arrested for DWI or when a crash occurs. This long term (or historic) versus concurrent (or focal) dichotomy has been extended by some researchers to psychological variables (Finch and Smith 1970). Table 4-7 describes the major types of variables which appear in the literature on psychosocial characteristics of drinking drivers. The important conclusion to be drawn from the table is that. just as the effects of alcohol consumption on the human body may be either chronic or acute, so may the effects of exposure to stressful events be chronic or acute. The implication is that analysis of relevant data should differentiate between the contribution of the two types of effects to crash involvement of drinking drivers. Since most drinking drivers and most alcoholics do not have crashes, it is apparent that neither acute nor chronic consumption of alcohol can fully explain the overinvolvement of drinking drivers and alcoholics in certain kinds of traffic accidents. Many researchers see psychological and situational stress variables as an important causal link. ALCOHOL AND HIGHWAY SAFETY I978 TABLE 4-7 Description of Variubles Commonly Used in the Literature on Psychosoc~ial Behavior, Alcohol Consumption, and Highway Safety Psychological Situational Stress Patterns of Alcohol Consumption Driving Behavior - - -. .. - - - . - Timc Frumr - - . - - -. -- Historic* Condition~ Retc~nt or Focul Ei+ent - - - -- -- -- Per$onality, attitudes. Pre-crash emotional state characteristic pattern of response to life events . - --~ Chronic exposure to stressful so- Acute stresses occurring around cia1 situations which may lead the time of crash which may to i~hnormal behavior triggered trigger certain emotions and by certain acute patterns of behavioral eniotional states. response. -. . - . - - .. - . Patterns of alcohol consumption. BAC at time of arrest for DWI especially as related to re- or at time of crash sponse to chronic stresses and as indication of problem drinking status . . . -. - - -- -- Patterns of driving behavior. Crash involvement. traffic ust~ally past traffic violations violations indicating possible prohlem driver gtatils - - Several studies have been conducted which found significant psychological differ- ences between accident-involved drivers who were drinking and nondrinking accident- involved drivers. Pelz and Schuman (1974) found that when they looked at a subgroup of a population sample of young men in which the subjects were either stro ~gly or strongly alienated or both, the members of this subgroup were, at each age level between 16 and 24, more likely to drink or to drink heavily than the remainder of the sample. As drinking. among this subgroup rose in frequency and amount, so did rates of traffic violation and crashes. No relationship between drinking behavior and driving infractions was found for those who were neither hostile nor alienated. The authors also examined a sense of personal efficacy among this subgroup of hostile and/or alienated young men and found that when sense of personal efficacy was high, there was no additional effect on driving behavior. However, when sense of personal efficacy was low, the effect of drinking behavior on rates of violation and crashes was stronger a11d more significant statistically. It is important to'oote that the measure of alcohol con- sumption used was historic rather than focal. Another study (Sterling-Smith 1976) examined focal use of alcohol and psychological traits of fatally injured crash-involved drivers. Drivers with BACs 2 .05% w/v scored significantly higher on 7 of 16 items on a Human Factor Stress Scale than drivers with BAC's < ,0596 wlv. This scale measured stress experienced by drivers immediately prior to fatal crashes. The seven measures on which the two groups differed signi- ficantly were domestic tension, social tension, clinical depression, fatigue, excessive speed for conditions, use of alcohol resulting in a BAC > -01% w/v and use of other PEOPLE WHO DRINK AND DRIVE drugs. Another finding of this study was that drivers with BACs 3 .05% wlv scored significantly higher than drivers with BAC < .O5% wlv on 6 of 12 items on a Risk Taking Behavior Scale. The six measures on which the two groups differed significantly were having a known problem drinking history, having been known to have attempted suicide, abuse of pharmaceutical drugs, experimental or frequent use of street drugs, normally driving without restraints, and smoking marijuana. Though age and BAC level at time of crash have been identified by other researchers as variables which are highly related to fatal crash involvement, recent studies (Fisher 1976; Schmidt et al. 1972) have found certain personality characteristics-belligerence, negativism, verbal expansiveness, hyperactivity-to be related to crashes, but, at the same time, to be unrelated to focal alcohol usage among the crash-involved sample. On the other hand, age and long-term patterns of alcohol usage were related to these personality traits in the general population studied. Selzer and associates (Selzer, Vinokur, and Wilson 1977; Selzer and Barton 1977) compared selected driving, personality, and psychosocial variables of convicted male drunk drivers with those of alcoholics and individuals from the general driving popula- tion. The drunk drivers were selected from a group of individuals who were participat- ing in mandatory rehabilitation programs following conviction in Michigan. The studies found that while a large percentage (40-68%) of the drunk drivers were alcoholics, they showed significantly less psychosocial "incapacity" than the alcoholic group. However, the nonalcoholics in the drunk driver group were found to be more malajusted than drivers from the general driving population. Alcoholics, when compared to drivers as a whole, were less responsible, had less self-control, had a more external locus of control, were more depressed and suicidal. had less self-esteem, and were more paranoid and aggressive. The drunk driver group was found to be more aggressive, more depressed, less self-esteeming, less responsible, and less in control of themselves than drivers in general. Selzer and Barton (1977) concluded that the forms of psychosocial impairment that existed among both the alcoholic and non-alcoholic drunk drivers were unlikely to respond to pre-arrest educational programs, but might be responsive to post-arrest rehabilitative programs. In general, research on personality and stress variables relative to the alcohol-crash problem provides useful clues and insights for describing some characteristics of drink- ing-drivers. However, the relationships between these variables and alcohol-related crashes are not sufficiently developed for use in predicting crash risk. Great care should be taken in applying the findings of this research to operational programs dealing with the drinking-driving problem. 4.3 SUMMARY AND CONCLUSIONS Much of the research on drinking drivers employs epidemiologic methods and is, therefore, subject to the same limitations outlined previously in Section 2.0 of this report. Additional problems with this method arise as one attempts to "cut" the data finer to arrive at more detailed conclusions. One finds that few studies have sufficiently large sample sizes or sufficiently detailed presentations of their data to support much ALCOHOL AND HIGHWAY SAFETY 1978 analysis beyond the next lower level of detail to that considered in Section 2.0. Even then, there are serious difficulties in many studies because confounding effects between variables often make it impossible to determine the degree to which each separate variable is associated with an observed effect. In addition, studies which rely on self- reported information about drinking and driving habits are obviously limited by the subjects' ability and proclivity to accurately recall and report such information. Simi- larly, analyses of information collected from the records of public and private organiza- tions are constrained by the accuracy, completeness, and currency of that data. At- tempts to combine almost any kind of drinking-driving data from more than one study are complicated (and sometimes made impossible) by inconsistent definitions, proce- dures, units, etc. A particularly serious deficiency in past research is the lack of sufficiently detailed controlled studies to assess accurately the alcohol-crash risk of most sub-groups of drivers. Without such studies. it is impossible to reliably determine the degree to which drinking drivers possessing a given characteristic are more likely than other drivers to be involved in an alcohol-related crash. On the positive side, much careful and useful research has been done in spite of these problems, most of which are common to many areas of the social sciences. As with the research described elsewhere in this report, its main value lies not in providing irrefut- able proof of hypotheses about drinking-driving, but in supporting informed decision- making. Thus, the information presented above must ultimately be interpreted by the individual reader in light of individual needs and situations. The summary and com- ments presented here are intended to help support that process rather than preempt it, and are neither definitive nor exhaustive in their content. The literature indicates that both drinking and driving have increased in the past 30 years, so that it is not surprising that we have a drinking-driving problem. The annual per-capita consumption of absolute alcohol in the U.S. has risen some 33% slnce 1947. Annual consumption of absolute alcohol is now about 2.7 gallons for each person over age 15 years in the U.S., an equivalent of approximately two drinks of 100-proof distilled spirits per person per day. A disproportionate amount of this alcohol is con- sumed by some 12% of the population who are classified as heavy drinkers (including 3- 4% who are alcoholics), so that most drinkers are probably consuming less than one 100-proof drink per day. It is hard to relate these figures on gross alcohol consumption to the categories of drinking types that commonly appear in the literature. It is possible, for example, for an "average" drinker to consume his entire quota. of drinks on a Saturday night and thus become a "problem drinker" once a week. Similarly, a "heavy" drinker could spread his higher consumption of alcohol more evenly throughout the week and never become a "problem drinker" at all. Thus, the amount of alcohol consumed or average rate of consumption does not alone determine whether a person is a "social drinker" or a "problem drinker." Frequency of attaining high BACs seems a better measure of the degree to which alcohol is a disruptive influence on one's functioning in society. A host of variables have been examined to learn more about the attributes of persons whose drinking has been associated with an inordinate amount of driving dysfunctions. Among those variables classified as biographical, sex has been found to be one of the I'C'OPLE WHO DRINK AND DRIVE best differentiators of drinking drivers. Males are consistently overrepresented in all kinds of drinking driver populations and are particularly frequent among crashed drivers with high BACs (i.e., greater than -08% wlv). The preponderance of males among drinking drivers is thought to be a consequence of social customs which call for males to do most of the driving, particularly at night when most drinking-driving occurs. One study found that at high BACs, females, in fact, suffered 4 to 5 times greater crash risks than males. With respect to ccge, both the youngest and oldest persons have been found less frequently than others among drinking drivers. The youngest drivers, however, appear to have a much greater alcohol crash risk after drinking (particularly at low BACs) than persons of other age groups. Inexperience with both drinking and driving has been suggested as a reason for the higher relative involvement of young drivers in alcohol- related crashes. In one study, older drivers had higher crash risks at higher BACs than other drivers. Studies of drivers' nl~rt.ittrl sttrtr~s have shown that married persons comprise the largest percentages of drinking drivers who have crashed and of drinking drivers using the road. However, as a group, divorced and separated persons seem to combine drinking and driving more frequently and may have a higher crash risk than persons of other marital statuses. The effects of marital status on drinking-driving are often con- foilnded, in the literature, with other effects (e.g., age). There are indications that persons of "lower" occrrpational levels are overrepre- sented among drinking drivers. but these findings are not conclusive because of the confounding effects of other variables such as age and sex. Increased alcohol involve- ment among nonw~1tiro.s has been explained in one study as a socio-economic rather than a racial effect. Persons in [OM' income groups were especially overrepresented among nighttime drivers in a nationwide survey, particularly at very high BACs (i.e., greater than . I>% wlv). where they outnumbered other drivers by a factor of three to one. Less rdrrccrted persons were found more frequently among drinking drivers in some older studies, but more recent studies show less of an educational effect except at high BACs. However, there is no convincing evidence that either occupational level, race, income, or education is strongly I-elated to alcohol/crash risk. Among the many driving variables that have been studied, time of day has shown some of the strongest relationships to drinking-driving patterns. As might be expected, drinking-driving is primarily a nighttime phenomenon. Drinking drivers are found two- to-four times as often in nighttime crashes as in daytime crashes. The same trend occurs among the nighttime driving population as a whole, particularly at the higher BACs. On the other hand. one study found one's relative risk of a "run-of-the-mill" crash after drinking to be substantially less during the nighttime than during the daytime. With respect to day c?f the ~~jc~ek, crashes and drinking drivers are also more frequent on weekends than on week-days. although the effect is not nearly as great as it is for time of day. Conflicting results have been obtained with respect to the relationships between an- n~rtrl tnilenge driven and drinking driving. There are indications that persons who drive relatively infrequently may be overrepresented both among crashed drinking drivers and among drinking drivers using the roads but not involved in crashes, but these ALCOHOL AND HIGHWAY SAFETY 1978 results are not conclusive. The relative risk of a crash after drinking may also be higher for the very-low-mileage driver. The origin ofthe trip which involved the illegal drink- ing-driving is most frequently bars or taverns and other person's homes. Research suggests that drinking drivers have had slightly more previous crashes and substantially more enforcement actions against them than other drivers. Drinking drivers have been found to have on the order of 50% more prior contacts with traffic law enforcement agencies than other drivers. Particularly, persons arrested for driving ~qhile intoxicated (DWI) generally have more prior driving convictions than other persons and perhaps more prior crashes. However, because of the lack of applicable controlled studies, it cannot be said conclu- sively that DWIs have a higher alcohol-crash risk than other drivers. The driving re- cords of DWIs have been found to be similar to those of fatally injured drivers with high BACs, but DWls' prior convictions for driving offense5 are more numerous than those of either fatally injured drinking drivers or noncrashed drinking drivers. The BACs of persons arrested for DWI are nearly always at illegally high levels. DWIs are seldom female, very young, or very old. They are usually arrested during weekends and at night and are often engaged in "low status" occupations. Among those driver-characteristic variables which are classified as "drinking vari- ables," the relationships that have been found with respect to drinking frequency and q~rnntity are in many ways the most enlightening. As might be expected, crashed drivers seem generally more likely to have a higher BAC than noncrashed drivers, regardless of drinking frequency. However. the ratio of crashed drivers to noncrashed drivers (and relative crash risk) tends to decrease with increasing drinking frequency, indicating that the more experienced drinkers are somehow better able to cope with the effects of alcohol in driving. One study which investigated the combined effects of frequency and quantity on drinking driving found a higher percentage of males among drivers who reportid a high Quantity-Frequency Index (QFI). Also, many teenagers were found to have high QFIs, but QFI decreased with a person's age. Fewer married persons had high QFIs than persons of other marital statuses. Heavy drinkers were more likely than others to engage in drinking at all BACs but had no more prior crashes or license suspensions. DWls were heavier drinkers than either fatally injured drivers or drivers not involved in crashes. There were indications that crash-involved drivers were slightly heavier drinkers than other drivers and that drivers in alcohol-related crashes were heavier drinkers than drivers in nonalcohol-related crashes. Studies that have investigated the type of beverage preferred by drinking drivers agree that beer is preferred by about two to one over other beverages by drinking drivers. An especially high preference of beer has been expressed by drivers with high BACs and drivers who report that they are heavy drinkers. The place of drinking most frequently reported by drinking drivers was their own home (two out of three). About 25% said they usually drank at public establishments or at parties. The higher BACs have most frequently been found among drivers who said they drank at public establishments. Much attention has been given in the literature to the drinking-driving habits of alcoholics and problem drinkers, although many studies do not provide precise PEOPLE WHO DRINK AND DRIVE definitions of the latter term. Studies do provide evidence that persons with severe drinking problems are highly overrepresented among fatally injured drivers who have high BACs (i.e.. greater than .lo% wlv). One study found problem drinking to be highly associated with drivers found to be responsible for the crashes in which they were killed. More than half of all DWls tested in three Alcohol Safety Action Projects were found to be problem drinkers. Other research indicates that alcoholics in particular have much higher crash rates than the driving population as a whole, perhaps even twice as high. Alcoholics may also engage in drinking-driving more frequently even than DWIs, especially at the higher BACs. Studies of porsontrlity tr~ld .stress variables that may be related to drinking-driving have not been conclusive and offer little reliable information for generalizing. There is some evidence that alienated and hostile young men are more likely than others to drink frequently and heavily and to be involved in crashes and traffic law violations. Such persons who are also low in personal efficacy may run even greater risk of involvement in a traffic incident. Further evidence exists that drivers who are inordinately tense, depressed, fatigued, and given to risk-taking may be especially likely to cause serious alcohol-related crashes. Some personality characteristics that are believed to be highly associated with highway crashes in general (e.g.. belligerence, negativism, etc.) have not been found to occur more frequently in alcohol-related crashes. In summary, research shows that drivers involved in alcohol-related crashes and persons who drink and drive but have not yet crashed tend to be different from other drivers in several important respects. Understanding these differences will help in de- veloping programs to reduce societal and individual losses caused by drinking and then driving. Misinterpreting them. however, can be counterproductive and even dangerous to both society and its individual members. No characteristic discussed above or any combination of such characteristics can identify any given individual as a sure-fire perpetrator of future alcohol-related crashes. In no instance can it be said that all persons possessing certain characteristics are high-risk drivers (e.g., alcoholics, young males). The data can help to determine the gross alcohol-crash risk of entire groups of drivers, but are far more difficult to apply to individricrl drivers. 5.0 DEALING WITH THE ALCOHOL-CRASH PROBLEM Research provides strong evidence that excessive drinking plays a major role in a large number of highway crashes in the United States and has furnished many useful clues for identifying the characteristics of groups of drivers who are involved in such crashes. The desire to "do something" to reduce the frequency of these alcohol-related crashes is therefore a natural one and, in fact. occurred long before a reliable scientific basis for action was available. This section of the report examines some past efforts to deal with the alcohol-crash problem with respect to their targets. their design, and their results. 5.1 ELEMENTS OF A SYSTEMATIC APPROACH TO THE ALCOHOL-CRASH PROBLEM In reviewing efforts made prior to 1968 to reduce alcohol-crash losses, the U.S. Department of Transportation noted that although a wide variety of approaches had been tried, rarely had scientific techniques been applied either to the development of control efforts or to the measurement of their effectiveness (U.S. Department of Trans- portation 1968). In a more recent article, Voas (1975b) observed that safety programs in general have suffered from a "knee-jerk" approach to the development of countermea- sures and have resulted in hastily implemented, unplanned efforts not likely to produce an impact. A more systematic approach to the problem would incorporate the following ele- ments: Target Identification, Program Design and Operation, and Program Evaluation. As depicted in the model in Figure 5-1, the results of past programs should provide a basis for identifying a specific target for control action in a particular location and for designing and operating a new program tailored to that target. The results of the new program should then be evaluated against its objectives (stated in terms of desired effects on the target). Findings of this evaluation should be used to improve the ongoing ALCOHOL AND HIGHWAY SAFETY 1978 Figure 9- 1. Elements of an alcohol-safety program I I 1 PROGRAM PROGRAM I I I I I DESCRIBE RESULTS OF PAST PROGRAMS program, and should be used in the development and evaluation of other new programs. In the subsections which follow, the three elements are described in more detail. 5.1. I IdentiJicution of Turgots ,fiw Control Action The clear identification of that which is to be controlled is perhaps the most funda- mental element of a carefully designed control effort. In the most general sense, it is a reduction in crash "losses" that is sought, but much more specific statements are required for operational usage. If by "losses," one means fatalities, it must be stated, for example, whether such losses are to be reduced by preventing some number of alcohol-related crashes from occurring or by decreasing the number of fatalities after the crashes have occurred (e.g., through use of passive restraints or through deploy- ment of emergency medical services). It is also necessary to state at the outset whet,ier the control measures are to be directed primarily at the vehicle (e.g., designing devices to warn other drivers and pedestrians of a drunk driver), at the highway environment (e.g.. designing signs more likely to be comprehended by intoxicated drivers), or at the driver (e.g., convincing him not to drive after drinking). Further detailed definition of the target of the control action must follow, e.g., specification of the type of drinkers whose driving behavior is to be modified. Figure 5-2 shows graphically how broad categories of targets for control actions against a given type of alcohol-related crash loss may be generated. Each of the three-dimen- sional cells represents a potential target of a program to reduce alcohol-related crash losses. For example, a program could attempt to reduce the frequency of fatal crashes due to hrrmun impairment by reducing excessive drinking among soci,?l drinkers in the DEALING WITH THE ALCOHOL-CRASH PROBLEM prc-cartrsh phase. More sharply defined targets could be identified by describing the target components in more detail: for example, the amount of impairment to be reduced (stated perhaps in terms of reductions in BACs) among male social drinkers by eliminating their desive to drink excessively in the pre-crash phase. The target-generating scheme depicted in Figure 5-2 is an expansion of an approach first suggested by Haddon and Brenner in the 1960s (Haddon 1968). 5.1.2 Design crud Development of Alcohol-Safety Programs A second major element of a rational approach to the alcohol-crash problem is the design and development of the program through which control is to be accomplished. Ideally, the methods used in such a program should be matched to the target so that the chances of a satisfxtory outcome are maximized. For example, if alcohol-related cra5hes are to be reduced by controlling the frequency of heavy drinking by problem drinkers, then the means for doing this should be appropriate for problem drinkers, who are different in many respects from social drinkers. Past alcohol-safety programs may most generally be classified according to whether they were directed at drivers as a whole, at drinkers, or at drinking-drivers. Examples of programs aimed at drinkers include prohibition and various state and local measures to restrict alcohol use among sub-populations of drinkers (e.g., laws establishing the minimum age at which one may purchase liquor). Programs aimed at treating alcohol "addiction" or at educating the general public on the symptoms of alcoholism are further examples of control activities directed at a more broadly defined group of drinkers, who may or may not be drinking drivers. Examples of programs aimed specifically at drinking drivers are campaigns to enforce DWI laws and public education programs on the greater crash risk faced by drinking drivers. The present report is concerned with this latter class of programs, i.e., those which specifically address drinking drivers. For purposes of discussion and analysis of past programs, the following five categories of such programs are defined: Legal, * Health. Public Information and Education. Technological, and Systems. Legal approaches to controlling crash losses due to drinking-driving are based on a set of official rules (laws) which specify and prohibit drinking-driving behaviors believed to present unacceptably high risks to society. Failure by the driver to comply with such rules results in punishments (e.g., fines, jail sentences) which are believed to act as a deterrent to the prohibited behavior. This deterrence is accomplished, according to the theory, either through the effect of the punishment in preventing the punished parties from engaging further in drinking-driving (called special deterrence in the literature) or by preventing most or all members of a given group from engaging in drinking-driving even if they are not caught and punished (called general deterrence) (Zimring and Hawkins 1973), ALCOHOL AND HIGHWAY SAFETY I978 Figure 5-2. Components of targets of alcohol-safety programs i EVENTS DEALING WITH THE ALCOHOL-CRASH PROBLEM Hctrlth approaches are aimed at the underlying drinking problems that often exist among individuals who drive with high BACs. (Filkins et al. 1970; Waller 1%8). Various treatments and therapies are applied to such individuals in an effort to induce more moderate drinking habits or to eliminate drinking entirely (e.g., Alcoholics Anony- mous). Rehabilitation programs (e.g., DWI schools) for all types of drinking drivers are also included in this category. Pl~blic' Information and Edrrc$cltiott (PI&E) approaches attempt to reduce the inci- dence of drinking-driving by campaigns informing and educating various population groups about the nature of the problem. Such programs address drinking drivers di- rectly by attempting to get them to refrain from the practice in the future or indirectly by attempting to enlist the support of other persons in actions against drinking-driving. A TV commercial designed to motivate persons to drive an intoxicated individual home from a party is an example of the indirect approach. PI&E approaches are most commonly used in combination with other approaches (e.g.. legafi. both to inform the public about the control actions that will be undertaken and to create a climate of public support for the alcohol-safety program. T~c*hrlo/ogic*trI apply modern technology to interdicting the sequence of events leading to drinking-driving. A wide range of technologies has been suggested for such cipplications. from pharmaceuticals designed to speed up the sobering process to ds\-,ices for measuring a driver's BAC. Most past and proposed programs for dealing with the drinking driver employ two or more of the above four approaches simultaneously. Few examples of "pure" ap- proaches are documented in the literature on alcohol and highway safety. Programs which methodically employ several approaches have been called systems approaches in the literature (Voas 1975b3. As with "pure approaches," few examples of full-scale systems approaches have been documented. Determining how well the control action has worked is the third major element in a carefully designed program for dealing with the adverse effects of drinking-driving. This step is essential for designing better control programs in the future, both by identifying actions that have worked so that they may be more widely applied, and by identifying actions that have not worl.cci so that they may be either improved or discarded. Recom- mended techniques for evaluating highway safety programs (including alcohol-safety programs) are described in a recent NHTSA manual (Vilardo et al. 1975). Current practices in the evaluation of alcohol-crash programs are discussed in later subsections of the present report. It will be seen that the evaluation of alcohol-safety programs has been difficult be- cause such programs usually have not produced an easily discernible effect. 'The mea- surement of such small effects and the provision of sufficient evidence to conclude that the effects were due to the program and not to some other factor, requires the use of sophisticated research designs and statistical techniques. For a variety of technical and practical reasons. such designs and techniques have seldom been applied with the rigor and care necessary to provide a clear picture of a program's effect. As a result, it is ALCOHOL AND HIGHWAY SAFETY 1978 sometimes concluded that an effect did not occur, when, in fact, the evaluation proce- dures were not sufficiently well-designed to detect the effect. Considerable care is necessary to avoid this logical pitfall when studying the findings of evaluations on alcohol-safety programs. The elements of a systematic approach to dealing with the alcohol-crash problem are turget ident$c'ation, program design and de~qslopmen and progrum e~qalrration. Proper target identification involves the detailed specification of the population, events, and flrcators to be addressed through the contemplated control actions. Past programs di- rected at the drinking-driving population may be classified as legal, health, public inj'or- mcrtion trncl education, t~cht~ologic~ctl, approaches. Programs must be etlalu- utcd in order to estimate their impact on the problem in light of the resources expended, and in order to provide information for future applications. In the following discussion, applications of the above five approaches are described. Specific programs have been chosen to illustrate the salient features of the approach they represent. Each approach is discussed with respect to targets, actions directed at the targets, and evaluation. as applicable. 5.2 THE LEGAL APPROACH As noted above, the concept of deterrence is the basis for the legal approach to controlling the drinking driver. The premise of deterrence is simply that a behavior can be prevented by the threat of punishment. It is significant that while deterrence is one of the most fundamental and important hypotheses i~nderlying criminal law and criminal law systems, it has not been the subject of scientific investigation until relatively recent times. Thus. one cannot say with any confidence exactly how deterrence operates to accomplish its objectives. One scholar has observed that "theories of punishment are moral c,lclims as to what justifies the practice of punishment--claims as to why, morally, it shor/ld or may be used" (Hart 1957). The most consistently stated theory of deterrence is that persons contemplatin* a prohibited activity will refrain from acting if the expected pleasure derived from the activity is less than the expected unpleasantness resulting from some threatened punish- ment (Andenaes 1952). It has also been suggested that punishment may deter more subtly by helping to educate the public about societally proscribed behavior. The result of such education is the development of inhibitions against the designated behavior (Andenaes 1952: Andenaes 1966). Deterrence may help to provide needed reinforce- ment for normally law-abiding individuals who may momentarily be tempted to engage in unlawful activity (Zimring and Hawkins 1973). It has also been observed that the threat of punishment may have an opposite effect to that intended. An individual who has been denied a freedom will sometimes experi- ence reactance in the form of an increased desire to engage in the forbidden behavior DEALING WITH THE ALCOHOL-CRASH PROBLEM (Brehm 1966). and individuals who have a pathological preference for punishment obvi- ously will be encouraged rather than deterred by the threat of punishment. Studies indicate that four factors are of primary importance to the deterrence process: characteristics of the target population, nature of the behavior to be prevented, target population's knowledge of the presence of the deterrent threat, and credibility of the deterrent threat to the target population. With respect to ttrrgrt poprilation, it has been suggested that both persons who are not inclined to be concerned about the future and impulsive persons may be poor subjects for deterrent programs (Zimring and Hawkins 1973). Individual differences have been found with respect to assessment of risk of apprehension (Joscelyn and Jones 1972) and willingness to take risks (Kaiffa 1968). indicating that persons will be differen- tially affected by deterrents. Differences in attitude and social status may also affect individual response to punishment threats (Zimring and Hawkins 1973). Highly social- ized individuals may be expected to respond to a given threat in a different manner from the so-called "anti-authoritarian" personality who rejects authority in any form. Per- 'sons of relatively "high" status may be better targets for deterrent measures than persons of "low" status, because the former group may have more to lose by a punish- ment and may have more loyalty to the society that contributed to their success. I he trcrti~re (?/'the hchtr~~ior bc pre\?cntotl is believed by most researchers to be an important factor affecting public response to an intended deterrent. One writer observed that "simple common sense indicates that a threat of punishment does not play the same role in offenses as different as murder, rape, tax-evasion, shoplifting, or illegal parking" (Andenaes 1966). Another writer speculates that "the effectiveness of deter- rence varies in inverse proportion to the moral seriousness of the crime," indicating that, in some cases, other social control forces may exert a greater "deterring" influence than the threat of punishment (Morris 1951). The motivations behind a given offense are also important: for example, alcohol addiction is a powerful motivating force which may be far stronger than any societally acceptable punishment. Obviously, the turgor popriltrtion'.~ of'rhc presence oj'the deterrent threat i\ required in any program of deterrence. This requires that both the fact that the behavior is prohibited and the fact that the behavior may be punished, be communi- cated to the public. Therf. i4 also a need to advise the public that behavior such as drinking-driving is dangerous to those who engage in it. The final major factor affecting public response to deterrent programs is the credibil- ity (?/'the deterrent rhrectt to the targrt popirlutiotz. It is generally agreed that no deter- rent threat will be effective unless those persons who might engage in the prohibited behavior believe that the threat is applicable to them personally and that the threat can be enforced. This means that a law really will be enforced and that no one will be immune, and it means that it (.(in be enforced. Further, the threat offered must be of a type that would cause the potential violator sufficient unpleasantness to outweigh the positive effects of the prohibited behavior. For example, loss of social status might cause more unpleasantness for certain individuals than dollars lost through a fine or even the loss of freedom suffered in serving a short jail sentence. ALCOHOL AND HIGHWAY SAFETY 1978 In discussing general deterrent threats to drinking-driving, Voas states the above principles on credibility in terms of two major factors: the probability of apprehension and processing through the judicial system so that a penalty is imposed, and the severity of that penalty (Voas 1975b). He asserts that probability of apprehension is related to: number of arrests in relation to number of licensed drivers, number of convictions in relation to number of arrests, and level of public information provided. He emphasizes the significance of public information for general deterrence, which is directed towards people who have not yet been punished for violations and must learn about the deterrent threat indirectly (Voas 1975b). The formal means for creating the deterrent threats employed in the legal approach to controlling drinking-driving is the system of institutions that generate and enforce laws. Joscelyn and Jones (1972) have described this Traffic Law System (TLS) as a social control system which functions to maintain drinking-driving risk (as well as other high- way transportation risks) at some societally-tolerable level. In doing this, the TLS per- forms four basic functions: law generation, enforcement, adjudication and sanctioning. The lcr~. function provides a set of laws and regulations governing drink- ing-driving behavior. Ideally, such laws should be clearly related to risk and should prescribe the necessary action to reduce that risk. Specifically, they should explicitly describe the levels of alcohol impairment that are intolerable in drivers and the means to be used by the TLS in dealing with such impaired drivers. The enjbrcaement function attempts to reduce the frequency of illegal drinking-driving either through the mere presence of policemen on the highway or through actual detec- tion and apprehension of illegally impaired drivers. The adjr~dication function determines the guilt or innocence of an individual charged with a violation of a drinking-driving law. The sunctioning function creates t1.e ultimate deterrent threat of the TLS by imposing punishment on the guilty parties. Such punish- ments are intended to prevent future drunk-driving by the violator and by drivers as a whole. It is interesting that, although public perception of a threat of punishment is a basic precept of deterrence and of the legal approach, no single component exists within the TLS, nation-wide, for informing the public about that threat. Traditionally, the system has relied on the news media, word of mouth, and various informal means for commur i- cating to the public the existence of a deterrent threat. One research study has recon- mended that a new, top-level function be established at the national level to collec~ information from and to disseminate information to both the general public and mem- bers of the TLS (Joscelyn and Jones 1971). NHTSA has performed this function for jurisdictions that have been involved in its Alcohol Safety Action Project. 5.2.2 Targets of the Legal ApproacA In most documented applications of the legal approach, targets have not been sharply defined. By definition, such applications have addressed human factors in the pre-crash phase but generally have not specified which human factors were being emphasized in which portions of the pre-crash sequence of events. In a review, presented in the 1968 DEALING WITH THE ALCOHOL-CRASH PROBLEM Report on Alcohol and Highway Safety (U.S. Department of Transportation 19681, of approaches which had been used to control alcohol-crash problems, it was concluded that the lack of specific definitions of population groups had led to "the use of 'shotgun' approaches directed toward the entire population that drinks . . . " The same report observed that the law had not yet distinguished one type of drinker from another and had not developed measures to deal with drinking drivers differentially. The report went on to note that by 1968 the scientific findings on the characteristics of drinking drivers wert: beginning to be emphasized in the legal literature and quoted the following state- ment made at an international conference in 1962: "since . . . no one type of drinker is exclusively responsible for alcohol-involved motor accidents, it is likely that no one type of approach would work eqi~ally well with all of those involved" (U.S. Department of Transportation 1968). The U.S. Department of Transportation's .4lcuhol Safety Action Project (ASAP) itppei\rs 10 be the first large-scale program in the United States to recognize the basic differences among drinking drivers and to develop cont1.01 measures specifically de- signed for different population groups (Voas 1975b). It accepted the findings of research on det~rrence that neither. the threat of p~~nishment the actual suffering of punish- ment is likely to have much effect on drinking drivers who have lost control of their drinkiiig. It reasoned that strictly legal approaches should be directed only at social drinkers whose motivations are more amenable to control by legal threats (Voas 197%). At almost the same time ASAP was being initiated, TLS officials in Chicago had conclirded, on the basis of :I local survey, that the social drinker was actually responsi- ble for most alcohol-related crashes. A program designed to deter social drinkers by the threat of "stern" enforcement was implemented hut was discontinued after seven months of operation. Foreign programs employing the legal approach have generally made no deliberate attempt to deal differentially with various categories of drinking drivers, even in recent years. For example. legal approiiches in Europe. Australia, and Canada have been targeted at all types of alcohol-impaired drivers. who were defined most typically (though not always) in terms of BAC (Birrell 1975: Carr, Goldberg, and Farbar 1975; Ro5s 1973; Ross 1975). 5.2.3 Appli(,(itio~/,s r110 ls~,voi' As stated above. the foj I, ai mechanism for applying the legal approach is the Traffic Law System (TLS) which generittcs and enforces applicable laws and then applies legal sanctions against those individuals it has found guilty of violating the laws. The nature of TLS activities relevant to controlling alcohol-crash losses is discussed below. Activi- ties of agencies that have been involved in various aspects ofpirhlic, informution related specifically to deterrence are also discussed. 5.2.3.1 LIII\> In the United States, laws about drinking-driving are gener- ated by state governments but may be supplemented or duplicated by local governments (Joscelyn and Jones 1971). In general, the laws attempt to proscribe risk behavior, usually in terms of what constitutes intoxication by alcohol, and to define what punish- ment (nearly always license suspension or revocation, fines, or imprisonment) may be ALCOHOL AND HIGHWAY SAFETY I978 or must be imposed against guilty parties. Laws also define the rules for enforcing. adjudicating, and imposing sanctions. At first. intoxication was described only in qualitative terms. but in 1939, Indiana enacted legislation making chemical tests admissible as evidence for prosecuting per- sons accused of driving while intoxicated (DWI). The law specified .IS% wlv as the BAC at which a driver is presumed to be "under the influence" of alcohol, but this was reduced to -10% wiv in 1971. In 1962. the Un/")rm Vrllic.1~ Codo recommended .lo% wlv as the BAC at which a driver is presumed to be intoxicated (Reese et al. 1974). Today, all states define impairment in terms of BAC measured by a chemical test. In 48 states. the Virgin Islands. and American Samoa. a driver with a BAC of -10% wlv or higher is considered to be impaired. In Idaho and Utah the maximum permissable level is .08% wlv (U.S. Department of Transportation 1974d). Some states have established more than one class of drinking-driving offenses. IJsually. one class defines impairment at ,1057 W/V IS?+ WIV BAC. and the other classes use lower values of BAC. Penalties for violation of the offense defined by the higher BAC are more severe than the lower- BAC penalties. A distinction is made in the laws as to whether the attainment of a specified BAC limit is "presumptive" or "per- sew evidence that the accused was actually impaired at the prohibited BAC. The specification of a BAC limit as presumptive allows the accused to submit evidence that he was. in fact. not impaired at the proscribed limit; or a prosecutor may produce evidence to show that a driver was. in fact. impaired at a BAC of less than that stated in the law. In states that have per se laws. driving with a BAC exceeding a given value is in itself illegal. At present. 10 states have per se laws, and nine of these states specify ,107; wlv as the legal limit. One state (Oregon) requires a BAC of at least ,1597 wlv as conclusive evidence of impairment (U.S. Department of Transportation 1975a. ch. I ). As noted. punishments specified in laws on drinking-driving commonly include fines. license suspensions, and license fc~-feitures. Typically. the laws provide for fines of up to $500. imprisonment for up to a year, and license suspensions of up to a year (Josce- lyn and Jones 1971). The suspensions are usually mandatory (Reese et al. 1974). Several states also require mandatory jail sentences for a first-offense conviction for DWI, and more than half of the states have mandatory jail sentences fur a second offense. In four states. the law allows vehicles to be impounded after conviction for DWI, and seven states provide for license plate suspensions for DWI. Numerous statutory provisions deal with the operation of the TLS in implementi~g the legal approach. For example, the manner in which chemical tests may be adminis- tered is prescribed by law. In 10 states. only breath tests are authorized; the other states authorize various combinations of breath, blood, urine. and saliva tests (U.S. Depart- ment of Transportation 1975a, ch. I). The principle of implied consent was introduced in New York in 1953 to induce people to submit to chemical tests. It states that when a person drives he implicitly consents to submit to a chemical test if asked to do so after being arrested for DWI. The principle was incorporated into the Un$)rm Vrhicale Codo in 1962 and has now been adopted by all states. Twelve states authorize a law enforcement office to administer a preliminary breath test (PBT) prior to an actual arrest, provided the rfficer has reason DEALING WITH THE ALCOHOL-CRASH PROBLEM to sr~spect that the driver is impaired by alcohol (U.S. Department of Transportation 1975a. ch. 1). Several states have attempted to expedite the processing of accused drinking drivers by passing legislation authorizing arrests to be made without a warrant, even if the police officer is not present when the offense is committed. Some states require manda- tory blood tests of drivers and adult pedestrians killed in crashes (U.S. Department of Transportation, 1975a. ch. I). Foreign countries have tended to set lower BAC limits for impairment and to specify more severe punishments for DWI than the U.S. For example, Canada's Breathalyzer legislation enacted in 1969 defined .08?+ wlv as the legal limit for BAC and authorized fines of up to $1.000 and imprisonment for periods of up to six months (Carr, Goldberg. and Farbar 1975 1. The British Road Safety Act of 1967 also limited BAC to .08% wlv and prescribed a mandatory punishment of a one-year license suspension and a fine of E 100, or imprison- ment for up to four months. or both (Ross 1973). The British Road Safety Act of 1967 also authorized a preliminary breath test when an officer had "reasonable cause" to 9uspec.t that a driver had alcohol in his body or had committed a traffic violation. or in the event of a crash. Refusal to take the test is penalized by a fine off 50. After such refi~si~l. arrest can still he made, after which the accused driver is given a second opportunity to take a test at a police station. Refusal to take the second test or a blood or urine test, is punishable as though the sample had been given and the test failed (Ross 1973: Department of the Environment 1976). All Australian states have enacted per se laws with a BAC limit of no more than .08% wlv (Birrell 1975). The state of Victoria has had a limit of .05V wlv since 1969. Norway, S~eden. Denmark all have BAC limits of ,0357 wlv and relatively strong punish- ments for violators. Likewise. the Netherlands has a BAC limit of .05% wlv, and its courts may impose a fine. imprisonment (up to three months), or license suspension (up to five years) for driving under the influence of alcohol (Van Ooijen 1977). Finland does not specify impairment in terms of BAC but provides stiff penalties, including a perma- nent revokation of license after a second offense (Ross 1975). 5.2.3.2 Enfbrc,cn~cnr. Enforcement practices in the United States, circct 1970. were reviewed by Joscelyn and .lo~les in a NHTSA-sponsored study (Joscelyn and Jones 197 1 ). Major steps dec;cri:)r d ilicluded: Detection. Apprehension, Initial observation. Decision making on further processing. Booking. Administering a BAC test. Processing refusals to submit to a BAC test, and Releasing the accused violator to await trial. The most common mode of detection was said to be officer observation of such manifestations of DWI behavior as "chronically high or low rates of speed, erratic ALCOHOL AND HIGHWAY SAFETY 1978 weaving, 'jack rabbit' starts, 'screeching' stops, and dramatic over-corrections of driv- ing errors." Apprehension of the suspected DWI (usually by pull-over) then followed. DWI arrests related to crashes were found to be uncommon because of the difficulty in determining whether an intoxicated participant was a driver or merely a passenger. DWI arrests as a result of citizen complaint were said to be less likely because of the necessity to have a motivated witness sign a complaint and have a warrant issued. It was common practice for the officer to make initial observations to help him decide if he should arrest the suspected DWI. "Field tests" involving the driver's picking up a coin, walking a straight line, etc., were commonly employed for this purpose. A recent study (Burns and Moskowitz 1977) found that, when properly given, field tests can be highly accurate in correctly classifying individuals as at or above .lo% wlv BAC. In some cases preliminary breath tests were used. but only with the driver's permission. What followed was the most critical decision in the enforcement process. The officer had to decide whether to: arrest the driver for DWI, arrest the driver for some lesser offense. or release the driver. Important factors influencing this decision were said to include: the lengthy amount of time required to "process" the suspect (often several hours). perceptions that the suspect would not be convicted or that the penalty would be too "soft." a tendency for the officer to identify with a suspect who is not believed to be really dangerous. and responsibility to remove a potential threat from the road. The net result was that often the suspect was either not charged or was charged for some lesser offense. In one jurisdiction with a population of 500.000 the arrest rate for DWI uas found to be less than 100 per year (Joscelyn and Jones 1971). Following arrest for DWI, the suspect had to be transferred to police headquarters for booking and then taken to a facility to have a BAC test administered. Typically, consid- erable paper work was involved, including the signing of a release for damage incurred in administering the test or the processing of a refusal to submit to the test, etc. AImter posting bond and sobering up, the suspect was then released to await trial (Joscelyn zild Jones 1971). Several detailed studies of the DWI enforcement process have appeared since 1970. The most comprehensive of these was conducted in late 1974 by Planning and Human Systems, Inc. (PHs) in order to obtain in-depth background information on enforcement activities in 22 jurisdictions participating in the ASAP effort (Planning and Human Systems. Inc. 1976). The study is significant because it attempts to describe actual practices rather than stated policies and is therefore directly comparable to the 1970 study. With respect to detection and apprehension of alcohol-impaired drivers, the PHS study found practices to be essentially the same as those described e,rlier by Joscelyn DEALING WITH THE ALCOHOL-CRASH PROBLEM itnd Jones. A few sites augmented their visual observations of erratic driving behavior with mechanical devices, including audio-recording. video-recording, radar, and heli- copters. One site was said to 'use stationary surveillance of drinking establishments to detect drinking drivers. The PHs study found that eleven of the 22 sites were using preliminary breath testing devices to assist in drc.ision-m(iking about whether to arrest the suspect'for DWI (Planning and Human Systems, Inc. 1976). 'Two other recent studies have investigated factors influencing a police officer's deci- sion to arrest a suspect for DWI. The first study, reported by Arthur Young and Co. in 1974 (Young & Co. 1974b). involved a survey of attitudes of police officers and supervi- sors at 16 ASAP sites. It found that an officer's personal beliefs about the nature and extent of the alcohol-crash problem affects his arrest decision, as does his tendency to identify with the su\pect; but certain operational factors, including lengthy and time- consuming processing procedures havc the most effect. Departmental factors found to be important included those affecting an officer's morale. The study found that the attitude and practices of other agencies (e.g.. Courts, prosecutor's offices) and of the community could strongly influence an officer's decision to arrest. The second study of the arrest decision was reported by Oates, also in 1974 (Oates 1974). It was concerned with the more general population of jurisdictions which were not a part of ASAP. Ele~en were deliberately chosen to represent a broad range of jirr-isdictions. Police pittrolmen. police supervisors, judicial personnel, and other officials were interviewed in order to ascertain their attitudes. The general findings were in agreement with the previous (ctudy of ASAP sites. Factors found to contribute to the decision to arrest included youth and relative inexperience of officer, his knowledge of alcohol and its effect on driving performance. his lack of a tendency to identify with a suspect. his perception that sanctions are not overly severe, his own accident involve- ment, high police mori~le and clear departmental policy on drunk-driving enforcement, and simple procedures for processing a suspect. The study found that persons from minority groups. young drivers, and female drivers tended to be arrested less frequently than others when suspected of DWI (Oates 1974). The PHs study of AS.4P enforcement procedures found post-arrest practices to be similar to those reported in 1970. A major difference at some sites was an apparent decrease in post-arrest processing time largely effected by making BAC testing more convenient, accomplished by increasing the use of breath testing devices located at the law enforcement agency (r'i:ir~i;ing and Human Systems. Inc. 1976). Studies of DWI enforcement prior to ASAP indicate relatively low levels of activity except for sporadic "crackdowns." Data from 73 jurisdictions compiled by Fennessey et al. ( 1968) indicate that a typical full-time enforcement officer made only 1.83 arrests per year for "alcohol impairment." The arrest rates varied widely among these jurisdic- tions. from a low of .02 per year to a high of 11.58 per year. Low levels of enforcement have also been observed in other jurisdictions (Joscelyn and Jones 1971; Newman, Dihrberg, and Rivo 1971; U.S. Department of Transportation 1975a, ch. 2). Borkenstein estimated that on the order of 2000 DWI violations occur for every arrest (Borkenstein 1975). a DWI violation being defined as a trip made while at a BAC of . lm w/v or more. The effect of ASAP has been to increase DWI arrests overall by a factor of two to DEALlNG WITH THE ALCOHOL-CRASH PROBLEM imposition of prescribed punishments. Three major decision pointr affecting the accom- plishment of this requirement are apparent from the preceding discussion: the decision to charge a suspected drunk driver with DWI when strong evidence exists that such it violation did occur. the decision to render a guiity decision against an individual who is guilty by legal standards, and the decision to select and apply a prescribed punishment against the guilty party. Ljocumented analyses of factors influencing thew decisions have been less formal than those referenced in the preceding section on enforcement. Factors said to inhibit a p~,osecutor from charging a suspect include a belief that conviction and punishment will nut sesult because of a "lenient" court. a belief that punishment will be too harsh. a lack of understanding of the alcohol-cr;ish problem. and a lack of sufficient resources to prepare and present case\ (Joscelyn and Jones 1971: Voas 1975b: Institute for Research in Public Safety 1972a: Wagner 1976). Similar tactors have been found to have an adverse effect on the adjudication and \anctioning functions, and the effect of overly-severe punishments is claimed by some experts to be especially serious (Joscelyn and Jones 1971). Voas listed six specific t~ainples "nullification" of the adjudicationisanctioning process by severe penalties. which caused the courts to be more likely to accept plea bargaining, less likely to convict. and less likely to impose even a mandatory sanctiot~ (Voas 1975b). The Chi- cago crackdown on drunken driving. cited by Voas, is an especially illustrative ex- iimpie. The Chicago judges agreed to impose :i 7-day jail sentence on all persons con- victed of DWI. but after six months only 557 of 6,600 drivers arrested for DWI had itctually seceived such a sentence. The operation of the ad.iudication and sanctioning process in a purely legal mode has not been subject to much quantitative analysis. Joscelyn and Jones (1971) reported case studies in two .jurisdictions that later became ASAP sites and found that nearly all of those arrested for DWI were prosecuted for DWI. Of those prosecuted. more than half were found guilty. Fines imposed were at the lower end of the range permitted by statute. and jail sentences averaged only about 1'12 weeks per conviction. License suspensions averaged about 6 months in one jurisdiction and 10 months in the other. Data from a mail survey of 344 New York State enforcement agencies, conducted by Newman. Dihrberg. and 3ivL) (1971 ). indicate that 17.6% of persons arrested for DWI in 1968 were convicted for 1lWI iifter trial. that another 17.7T pleaded guilty to DWI or some lesser offense. and that 26.35; of the cases were still pending at the end of 1968. The New York data also indicate that some 27% of those arrested were never prose- cuted for DWI. nos wese they prosecuted for any lesser offense. The data collected in a nationwide mail survey conducted in 1970 by Joscelyn et al, indicated that in most of the responding jirrisdictions. a fine was typically imposed for a DWI conviction and that ,init sentences were relatively infrequent (Joscelyn. Maickel. and Goldenbaum 1971). License suspensions were used in 58% of the jurisdictions. License revocations were imposed in 439 of the jurisdictions. Data reported by ASAP sites showed that about 54% of persons arrested for DWI were actually convicted of DWI. However, in some sites, many individuals were pur- ALCOHOL AND HIGHWAY SAFETY 1978 posely "diverted" from the legal systcm in the pre-trial phase to participate in treatment and rehabilitation programs. and this undoubtedly resulted in a lower conviction rate than could have been obtained under a purely legal approach. Some sites which did not engage in pre-trial diversion reported much higher conviction rates; for example. Denver. Vermont. and Oklahoma City had conviction rates of 66%- 81%. and 69%, respectively (U .S. Department of Transportation 1975a, ch. 4). There is evidence that the legal approach in many foreign countries has resulted in surer and more severe punishments for individuals arrested for DWI than it has in the U.S. In 1968, 70% of all persons convicted for DWI in the Netherlands received prison sentences (Farmer 1973). In Sweden. 40% of prison sentences are for DWI (Farmer 1973). In the three years following the implementation of the British Road Safety Act of 1967, conviction rates averaged more than 9OV, compared to 80% before the Act (Herrick 1973). 5.2.3.4 P,rhlic lnfi)r~?~cition. British Road Safety Act of 1967 (Sheppard 1968) is a prime example of the uue of a public information campaign to support a legal approach. The Act went into effect on October 9. 1967. A large-scale publicity program on the new legislation was launched on September 25. 1967 and ended December 31. 1967. The objectives of this campaign here to inform the public of: the BAC limit which would be considered evidence per se of intoxication. the procedures which woilld be followed by law enforcement officers in appre- hending. arresting, and testing the motorist suspected of impaired driving, the penalties associated with conviction under the new law, and the dangers to individuals and to communities of driving while impaired by alco- hol. The function fulfilled by this type of information campaign has been in,erpreted as increasing the probability of apprehension perceived by the public (Ross 1973; Wilde 1975). It is theorized that the legislation of interest is more likely effectively to deter proscribed behavior when the perception of apprehension is positively reinforced by increased enforcement of the law. The perception of apprehension was apparently increased by the Act (see section 5.4.6). and a signiticant decrease in "casualties" per 100 million vehicle units was noted (Ross 1973). However, three years after the Act was implemented, the rates bega.3 to approach their former levels. Ross (1973) attributes this decay in program effectiveness to a realization by the public that the actual probability of apprehension was mu~h lower than was at first perceived, resulting in an erosion of the deterrent effect. A more recent analysis of the Act (Department of the Environment 1976) found indications that the effects of the Act may have been more lasting among drivers in the 40-60 age group and that they wore off most rapidly among those in the under-30 age group. The analysis noted that the efforts of the PI&E campaign had continued to diminish and that, as a result, younger persons who were just reaching driving age had not been exposed to it. Breathalyzer legislation was enacted in Canada and became effective in December 1969. Enforcement of this law in Canada was followed by an increase of 50% in the DEALING WITH THE ALCOHOL-CRASH PROBLEM number of drivers tested for BAC. The introduction of the new law was accompanied by a widespread information campaign: and during the first year in which the new legislation was effective, there was also emphasis placed by federal safety agencies on motor vehicle safety standards. No significant decrease in fatal crashes was attributed to the legislation. The enactment of Breathalyzer legislation in Canada has been compared with the enactment of similar legislation in Great Britain. The British Road Safety Act of 1967 was followed by a more dramatic and lasting decrease in drunk driving than the Cana- dian legislation, even though enforcement in Great Britain was not significantly in- creased. lmportant differences bctween the two cases are: 0 Canadian police officers must have evidence of impairment before requesting a breath test; in Great Britain, the only prerequisite is evidence of drinking, moving violation, or accident involvement; 0 roadside screening tests cannot be required in Canada: they can be required in Great Britain; the Canadian public had greater familiarity with breath testing than residents of Great Britain: thus, the Canadian legislation had less "shock value" (Carr, Gold- Perg, and Farbar 1975). IP a study of the effects of a public information campaign conducted by the Vermont ASAP (Worden. Waller, and Riley 1975). the evaluation design included comparisons among the effects of an educational campaign wed alone, an educational campaign conducted in conjunction with increased enforcement of drinking-driving laus, and a control condition in which there was no educational campaign and no increase in en- forcement. The findings of this study were that the educational campaign was most effective when combined with increased enforcement and that the educational campaign when used alone had a more positive effect than no educational campaign. These findings support the interpretations (Planning and Human Systems 1976: Wilde 1975) cited above that perceived probability of apprehension and actual probability of apprehension are directly related. Public information campaigns thus appear essential in accomplishing a general deterrent effect through a legal approach. NHTSA has recogn- ILW the importance of public awareness of the threat of apprehension and has initiated a new program of research in this area. The literature provides few examples of alcohol-safety programs which have incorpo- rated an evaluation component into their overall design. Most evaluations have oc- curred after programs were completed and have been performed by researchers who did not participate in the program. Buikhuisen and his associates at Groningen University in the Netherlands, among the first to engage in these post hoc evaluations of the legal approach. found that neither severe punishments nor withdrawing drivers' licenses had any apparent effect on reducing future violations (Buikhuisen 1969; Buikhuisen 1972b). The Dutch researchers found that more than 36% of a group of DWIs were reconvicted for DWI within 10 years, despite the relatively strong sanctions that were applied (Buikhuisen 1969). ALCOHOL AND HIGHWAY SAFETY 1978 Ross has performed analyses of crash rates in the Scandinavian countries during the period of time when their increasingly severe drinking-driving legislation was being developed. Various points in the development of these laws were the subject of pre- and post-examination. No changes of significance were revealed for different types of crashes or for different types of sanctions for any of the four countries (Ross 1975). More recently, some of the Scandinavian data was subjected to economic analysis, and it was concluded that Scandinavians had been responsive to increased law enforce- ment activity (Votey 1976). The study found that "legal sanctions" strongly reinforced an individual's tendency not to drive after drinking and that the Scandinavian data suggested that both law enforcement and control of alcoholic beverage sales influence the level of crashes. In one of the better known post 110~ Ross analyzed the effect of the British Road Safety Act of 1967 (Ross 1973). He used the technique of the interrupted time series analysis, a method by which trends in accident rates can be examined over large 5tretches of time both before and after enactment of the legislation. Ross deter- mined that the 1967 law was effective for a period of three years in decreasing the rate of accident casualties. Evidence was also found that the public engaged in less drinking and driving. A pre- and post-survey of adults found that more people said they walked to drinking sites and fewer admitted to drinking and driving. In addition, among traffic fatalities, there was a smaller percentage who had illegally high BACs. Ross attributed the effectiveness of the 1967 Act to the public education campaign which led drivers to believe that the chances of their being apprehended when drinking and driving were great. After the driving public learned that there was little increased enforcement of drinking-driving laws, they adjusted their estimate of the chances of apprehension accordingly. Consequently, the effectiveness of the Act decreased (Ross 1973). There are indications that the program of drinking-driver control acconlpanying the 1974 Dutch legislation limiting BAC to .05% wlv may have had an effect similar to the British Road Safety Act. A preliminary analysis by Noordzij (1977) found a sharp decline in the percentage of drunk drivers (i.e., BAC 3 .05% wlv) using the road immediately following the introduction of the legislation, followed by a rise in drunk driving one year later. In contrast to the British Road Safety Act, the Breathalyzer legislation in Canada appeared to have little effect, even in the short term (Carr, Goldberg and Farbar 1575). The average BAC of breath-tested drivers did not change significantly after the raw became effective. During 1970, there was a decrease of 6.3% in the total number of fardl crashes, using the year 1969 as a comparison. However. in the U.S., fatal crashes declined 2. I%, though comparable legislation was not enacted. In the U .S., the so called "Chicago crackdown" in 1971 was evaluated a posteriori by Robertson et al. (Robertson, Rich, and Ross 1973), using the interrupted time series technique. They found that there was no statistically significant change in Chicago's accident rate resulting from the program. This finding held true for fatalities, DWI arrests, and DWI convictions (except for those drivers who were not tested for BAC). (There was not an implied consent law in Illinois during the program.) The change in Chicago's accident rates was seen by these researchers as part of a long-term trend. DEAI.1NCi WITH 7HE ALCOHOL-CRASH PROBLEM When Chicago's long-term trend was compared with nearby Milwaukee's, no significant differences were found. Milwaukee has a police-court system and climate which are similar to Chicago's. NHTSA's ASAP program was designed from the outset to be evaluated. It sought to assess the impact of both the overall program and its individual "countermeasures" on a variety of ultimate and intermediate program objectives. However, because ASAP employed a systems approach. simultaneously applying elements of the legal, health. public information and education, and technological approaches, it is impossible to say exactly which element. if any. was responsible for what part of the results. The best available indication of a positive effect of the legal component could appear to be a negative correlation between DWI arrest rate and crash rate. No such effect has been found by the NHTSA evaluators of ASAP. Their evaluation of 1974 operations stated: No simple relationship of enforcement and crashes has been established in the ASAP project. In several instance\, fourfold and fivefold increases in arrest have not been able to have an impact on the crash level" (U.S. Department of Transportation 1975a, ch. 2, p. 23). The NHTSA evaluators speculated that a possible explanation for this disappointing rehul: was that the target population had not perceived the increased enforcement threat or that this thseat was still not high enough. In an analysis of earlier ASAP c.nforcement data, Zylman grouped the data in a manner which suggested that nighttime fatal crashes actually increused with increasing enforcement intensity (Zylman 1975). The statistical significance of this relationship was not discussed in Zylman's analysis, and he concurred with the official (i.e., NHTSA) evaluation report's statement that "there is no evidence of a relationship between alcohol-related arrest activity and the change in level in nighttime crashes" (U.S. De- partment of Transportation 1974~). NHTSA is currently evaluating the effects of increased DWI enforcement in one local jurisdiction (Hause et al. 1977). The study is employing control groups in an attempt to measure the impact of enforcement activity on several drinking-driving variables (in- cluding drinking-related crashes). The results of the study should be helpful in under- standing how one component of the legal approach (i.e.. enforcement) affects the fre- qtlency of alcohol-related cra5hes. More research is needed to describe the effects of other TLS components (c: :.. sanctions) on the alcohol-crash problem. Thus, evaluations indicate that most past applications of the legal approach have not been effective in promoting either general or special deterrence of drinking drivers. The one program with a clear positive impact on the alcohol-crash problem, the British Road Safety Act of 1967, relied on a strong public information component to create a public perception of great risk of apprehension. In this case, perceived risk probably exceeded actual risk by a substantial amount. Actual risks of apprehension do not appear to have been sufficient in past programs to have posed much of a deterrent threat. Research suggests that a driver in the U.S. would have to commit some 200 to 2000 DWI viola- tions to be caught. After apprehension. he would still stand only a 50-50 chance of suffering no more than a relatively mild punishment. Such a threat is apparently accept- able even to most social drinkers, who are able to control their drinking. ALC'OHOL AND HlGHWAY SAFETY 1978 5.3 THE HEALTH APPROACH In recent years it has become more and more popular in the United States to regard problem drinking (including alcoholism) as a health problem rather than a crime. In 1967, the President's Commission on Law Enforcement and Administration of Justice estimated that from 40 to 49 percent of all non-traffic arrests in the U.S. were for alcohol-related offenses (President's Commission on Law Enforcement and Administra- tion of Justice 1967). The commission recommended that "drunkenness should not in ' itself be a criminal offense" and that drunkenness be taken out of the Criminal Justice System by establishing detoxification units as part of comprehensive treatment pro- grams and by coordinating and extending after care resources. The recommendations were no doubt influenced by two landmark court decisions, Easter v. District of Colum- bia (1966) and Driver v. Hinnant (1966). holding that alcoholics could not be convicted for drunkenness. The impact of these two decisions was moderated shortly thereafter (in 1968) when the Supreme Court held in Powell v. Texas (1968) that chronic alcoholics could be punished by the criminal justice system if convicted for criminal conduct which is not a characteristic and involuntary part of the disease of alcoholism. Nevertheless. advo- cates of the health approach continued to press for treatment of alcoholism rather than punishment, as evidenced by the Uniform Alcoholism and Intoxication Act promulgated in 1971 by the National Conference of Commissioners on Uniform State Laws (1973). The policy of the act was that "alcoholics and intoxicated persons may not be subject to criminal prosecution solely because of their consumption of alcoholic beverages but rather should be afforded a continuum of treatment in order that they may lead normal lives as productive members of society." The provisions of the act were first adopted in the state of Washington in 1972. and other states have since adopted part.. of it. The federal Comprehensive Alcohol Abuse and Alcoholism Prevention. Treatment, and Re- habilitation Act Amendments of 1974 authorized $13 million in federal support to those states that enacted the Uniform Alcoholism and Treatment Act (Chafetz 1975). Paralleling the movement to treat rather than punish drunkenness, some highway safety specialists were recommending a health approach for dealing with the drinking driver. At a conference in 1969, Filkins of the University of Michigan describe< the major functional elements of such an approach as case-finding, diagnosis. prescription, treatment, follow-up, and evaluation (Filkins 1969). He recommended that the le)~al system and the health system better coordinate their efforts in performing these furc- tions. Filkins also recommended that the legal system act "as the primary case-finders for the immediate future, and (it) should continue to play a prominent role in these functions" of a "combined health-legal approach." Joscelyn and Jones (1971) further developed the concept of a combined approach in their 1970 study which envisaged a Drinking-Driver Control System consisting of agencies of the Traffic Law System and an even more informal Alcoholism Control System which attempted to treat and reha- bilitate drunken drivers. Studies of the past operation of this conceptual Drinking- Driver Control System in various jurisdictions revealed a general lack of coordination among the various agencies involved and a lack of motivation to apply available re- sources and methods (Joscelyn and Jones 1971; Joscelyn and Jones 19'2). Over half of DEALING WITH THE ALCOHOL-CRASH PROBLEM jurisdictions responding to a nationwide mail survey said they attempted in some fa- shion to refer problem drinking drivers to treatment (Joscelyn, Maickel, and Golden- baum 1971). NHTSA's ASAP program followed and has placed heavy emphasis on dealing with the problem drinking driver through a coordinated, systematic, healthllegal approach (U .So Department of Transportation 19744. .4ctual implementation of the healthllegal approach has not been without its prob- lems. Some scholars have even questioned whether it is proper for the legal system to participate in non-legal modes of rehabilitation. For example, Lewis (1953) presents the argument that such involvement does not support the cause ofjustice, which is properly concerned only with whether a punishment is deserved and not with whether it will deter or cure. Rubin (1968) argued that treatment is not necessarily humane and may be an invasion of human rights. Practitioners have experienced great difficulty in applying the approach because of conflicts in the ob.iectives and roles of the legal and health institiitions involved (Aiken and Weiner 1974). 'The literature offers little evidence of large-scale applications of other case-finding tschniques for bringing drinking drivers into treatment and rehabilitation programs. Filkins has provided an extensive list of possible non-legal system techniques for identification of problem drinkers by hospitals, alcoholism treatment facilities, health care professionals. social service agencies. employers and unions, insurance under- uriters. etc. (Filkins 1969). but there is no record of any program which has employed these techniques to any large extent. Thus, for all practical purposes, health approaches to controlling drinkihg drivers have really been combined healthllegal approaches. By its very nature, the health approach is directed at controlling the precrash behav- ior of drivers. The population group dealt with is predetermined by its most common mode of entry into treatment and rehabilitation programs and is, therefore, composed of persons arrested for and, for the most part, convicted of driving while intoxicated or some similar offense. As such, nearly all members of the group will have been legally drunk (BAC 2 . IOF wlv) at the time of their arrest, and some 50 to 75 percent of them h;!~ r: been classified as problem drinkers in several studies (see Section 4.0). The re- maining 25 to 50 percent will be either heavy social drinkers or (a few) moderate or light social drinkers who rarely ccvstrme such large amounts of alcohol. Further a priori breakdowii of target populations in order to provide treatments more suitable to specific needs does not seem to have occurred as a part of any deliberate plan in most jurisdictions. The 1970 survey of court procedures for handling problem drinkers found some jurisdictions using fairly sophisticated procedures to ascertain u hether a DWI needed treatment. As a result of these procedures, an equally wide range of treatments was being "prescribed" (Joscelyn, Maickel, and Goldenbaum 1971). This suggests at least some implicit attempt to deal differentially with subgroups of the DWI population. Similarly, several of the Alcohol Safety Action Projects (AS- .4Psi which used the protocol developed by HSRl for identifying problem drinkers regularly classified individuals beyond the usual problem-drinker/social-drinker omy in order to permit more specific referrals (U.S. Department of Transportation 1975a. ch. 4). Even the prototype DWI course developed by Arizona State University ALCOHOL AND HIGHWAY SAFETY 1978 and applied in Phoenix, Arizona. over I0 years ago was used selectively by magistrates, but it is not clear exactly what criteria were followed in assigning persons to the course (Stewart and Malfetti 1970). One application of the health approach addressed a very special group consisting of airmen stationed at Lackland Air Force Base in Texas (Barmack and Payne 1961a). When found to have been involved in a crash, the airmen were required to undergo review by their squadron commanders and by a psychiatrist for possible further action. which included psychotherapy and discharge. In Holland, some DWIs were sentenced to a special prison where information on traffic safety and an opportunity for treatment were offered (Buikhuisen and Steenhuis 197 I). In summary, most applications of the health approach to the general public in the United States have explicitly addressed two major target populations: heavy drinkers (including alcoholics, problem drinkers, and heavy social drinkers) and light to moder- ate social drinkers, Implicit target groups identified retrospectively have been defined to correspond with the most appropriate treatments available. 5.3.2 Applica(~tions the Hcaltll Appro~c'h As noted above. many of the functions of the health approach to drinking-driver control in this country have often been performed and influenced by the Traffic Law System (TLS), resulting in what Filkins (1969) has appropriately described as a "com- bined healthilegal approach." Formal analyses of various operational configurations of the "systems" involved in this approach were performed in the early 1970s by other researchers (Joscelyn and Jones 1971; Joscelyn, Maickel, and Goldenbaum 1971) and have continued periodically under the ASAP program (U.S. Department of Transporta- tion 1975a; Struckman-Johnson 1976: Ellingstad 1976). These analyses suggest that in its most general form, the mode of operation of this Drinking-Driver Contro' System can be depicted as in Figure 5-3. The diagram shows that in addition to its usual functions of law generation. enforcement, adjudication, and sanctioning, the TLS takes on the public health functions of casefinding. diagnosis, and referral. The final health functions of treatment and rehabilitation are performed by another. less well-oganized societal sys- tem termed, in one study (Joscelyn and Jones 1971), the Alcoholism Control System. The nature of the functions. processes, and interfaces of various forms of this concep- tual Drinking-Driver Control System are described in the following sections. 5.3.2.1 Health-Lrgal Filnc.tions (?/'the Trcijfic. Llrw System. The initial health funciion of the TLS is that of c)~sc-finding, individuals among the general population who pose an unacceptably high risk of causing an alcohol-related crash. As in the case of the pure legal approach, TLS legislative and enforcement components have been the primary performers of the case-finding function by proscribing risky behavior in terms of laws and regulations and then arresting violators of the laws. In general, the content of these laws and the manner in which they have been enforced have not been such as to differentiate drivers according to whether they are subsequently to be dealt with through a legal approach or a health approach. For all practical purposes, problem drinker-drivers and social drinker-drivers are treated alike with respect to case-finding (see Sections 5.2.3.1 and 5.2.3.2). DEALING WITH THE ALCOHOL-CRASH PROBLEM ALCOHOL AND HIGHWAY SAFETY 1978 The diagnosis and ryfkrrtil functions are concerned with determining the nature of the problem that brought the individual into the Drinking-Driving Control System, and with specifying how the problem is to be treated (Joscelyn and Jones 1971; Joscelyn, Maickel, and Goldenbaum, 1971; U.S. Department of Transportation 197Sa). The func- tions are performed by the adjudication and sanctioning components of the Traffic Law System within the constraints provided by the body of law. The formal mechanism used by the TLS is the probation system through which an individual is offered treatment in exchange for a less severe andlor a suspended sanction. Little (1970) has used the term "coercive volunteerism" to describe this judicial use of the probation power. Referral to medical treatment by direct sentencing is not authorized in any state, but several states authorize civil commitment for chronic alcoholics (Reese et al. 1974). The approach has seldom been used in dealing with problem drinking-drivers (Joscelyn and Jones 1971: Joscelyn, Maickel, and Goldenbaum 1971). By contrast, referral to non- medical rehabilitation (i.e., DWI schools) has been authorized by statutes in several states (Reese et al. 1974). An extremely wide variety of procedures and methods have been used in performing diagnosis and referral, especially since the start of ASAP. Some jurisdictions perform the two functions even before the adjudicative hearing has occurred. In these jurisdic- tions, the prosecutor plays a key role in the process, determining both the nature and the provider of the treatment. The prosecutor obtains the driver's agreement to undergo treatment andlor rehabilitation in exchange for a promise not to prosecute for the original DWI charge or. in some cases. uny charge. When all charges are dropped. "pretrial diversion" is said to have occurred, and the prosecutor performs the tradi- tional probationary function of the court. In other jurisdictions, it is more common for diagnosis and referral to occur after the adjudicative hearing. Here, the normal procedure is for the judge to perform the two functions, usually before (but sometimes after) sentencing. In a relatively small percent- age of jurisdictions, diagnosis and referral may occur during the treatment process itself, for example, while an individual is attending DWI school. Table -I illustrates the diversity of the diagnosis process among the sites which participated in ASAP. It is apparent that several of the sites used hybrid approaches or employed different approaches depending on the circumstances. The presentence ap- proach (either alone or in combination with other approaches) was by far the most common, occurring in 29 out of 35 ASAPs. A critical support function to diagnosis and referral is the provision of information for decision making. The formal means by which such information is provided is mislead- ingly called a presrntencc in\-estigution (PSI) because it was originally used in felony cases just prior to sentencing (Reese et al. 1974). Reese et al. (1974) observed the close linkage between PSIs and the Federal Probation Law of 1925 which led to statutory recognition of PSIs in the Federal Rules of Criminal Procedure in 1946. The kinds of information included in a PSI for use in drinking-driving violations vary widely. from driver records to a broad range of social, psychological, medical, and economic background information (U. Department of Transportation 1975a, ch. 4). The comprehensiveness of some PSI reports (not necessarily for DWl) has. in fact, led the American Bar Association to warn of unwarranted invasions of privacy that might DEALING WITH THE ALCOHOL-CRASH PROBLEM TABLE 5-1 S~OAJ~S Btrc,kgrolrnd In~~ostigcrtion-L>iu,yr1osis ut ASAP Sitrs P~.oj(~c,t Prctriiil Albuquerque .................... X Charlotte ....................... X Denver ........................ ...................... N;ISS;ILI County. N.Y. .............. Portland-Eugene .................. Seattle ........................ Vel'mont ....................... Washtenau County. Mich. ........... B~~ltimore X Boston ........................ ...................... C'olumbus. Ga. ................... X I;, ' . ............... 'ill fax County. Va. X ............ Indianapolis ..................... ..................... X 1.incoln ....................... Tampa ........................ .................. X Neu Orlean\ .................... ................... Phoenix ....................... X Portland. Me. ................... X Pulaski County. Ark. .............. X Richland County. S.C. ............. X S~rn Antonio ................... South Ditk<~t>t Wichita ........................ X Delauare ................... ... Idaho ........................ .............. ..................... ................... ...................... - Pt r!rntrnt r Po~t\et~trncr lrrutment Soul.ce: U.S. Department ut' Transportation 19752. ch. 3, p. 7. ALCOHOL AND HIGHWAY SAFETY 1978 result from delving too deeply into a person's background (American Bar Association 1958). The survey of court procedures conducted in 1970 by Joscelyn et al. (1971) provides a rough idea of the level of detail of PSI information prior to ASAP. The survey found that approximately one-half of the 1778 jurisdictions polled said they used testimony from the DWI and arrest records to ascertain whether a convicted DWI needed treat- ment for a drinking problem. Some 30% stated they used information collected in court-conducted interviews with the driver and/or contacts with friends. relatives, and employer. Twenty percent said they reviewed the violator's drinking patterns. Fewer than 10% consulted social case histories. conducted medical examinations, performed psychological diagnoses, or were assisted by social workers. Nearly one-third of the respondents said they used no formal procedures. Site visits to eleven jurisdictions believed to favor the health approach to the drinking-driving problem revealed "for- mal" PSIS to be the rule. but such PSIS typically involved only an interview with a probation officer. At four sites the judge performed the PSI in a five- to ten-minute interview. Eight sites occasionally used some sort of psychiatric interview or psycho- logical test as a tool. Sources of information for diagnosis and referral at ASAP sites were listed in NHTSA's evaluation of 1974 operations as: a check of the offender's driving and criminal records for arrests and convictions involving alcohol, including BAC at the time of arrest. a check for previoos cont;sts with local health or social service agencies. a personal interview of the offender by the presentence investigator, an interview with the offender's family, friends, and employer, a written diagnostic test of problem drinking. and an in-depth medical or psychological evaluation by physicians, ps ~chologists. psychiatrists, or psychiatric social workers (U.S. Department of Transportation 1975a. ch. 5). The number of sites using each source of information or the specific data items included in the various sources was not stated. However. the evaluation report did present data which suggested that in 1973 all PSIS included record checks, that more than one-half involved personal interviews, and that about one-third included in-depth examination. The major uses of the PSI information in ASAP were to deterrr.'ne whether an individual was a "problem drinker" or a "social drinker" (U.S. Department of Transportation 1975a. ch. 4) and to aid in referral. Early in the ASAP program. NHTSA sponsored the development of a detailed proto- col for identifying problem drinking among drivers who have been arrested for DWI. The Highway Safety Research Institute of the University of Michigan was the contrac- tor and devised a two part questionnaire and accompanying procedure (Kerlan et al. 1971) that was widely used in the ASAPs. The first part of the questionnaire is self- administered while the second part is conducted by an interviewer. Both together re- quire about an hour to administer. Studies of the HSRI protocol (often called the Mortimer-Filkins test after its two principal authors) have shown it to be one of the most accurate discriminators of problem drinking drivers yet devised (Jacobson 1976). DEALING WITH TfiE ALCOHOL-CRASH PROBLEM Leas explicit gl~idance exi4t4 for making ~.cfe~.~.itls diagnosed as problem cl~.inkers. i~ltho~~gh 01' the factors influencing the selection of providers of care are ~iientioned in the HSRl protocol (Kcrliln et ul. 1971). It seems likely that the qi~bjective ,i~~(.Ignients the in\ol\cd T~.;rf'tic I,:IM System personnel have most often been the basis for mirking I.c~'cI.I-~I~s. thc hasis. in I972 and 1973. nearly 80.000 individuals entc~.ed tl.catnicnt ;lnd rchitbilitation in the ASAP projects (L1.S. Department of Trans- po~.t:rtion lc)75;1. ch. 5). This iimoi~nted to abol~t ;I third of all persons arrested for DWI and more than XO'Z of pelwns undergoing PSIS in those tho years. 5.3.2.2 7'11c~ ( 'otlr1.01 S,~..\tot?r. A full discussion of the operation of the ~c)n~t'ptt~itl Control Sy4tem" u hich pcrKorms the t~.c.trtttlont tri~d rc~llrrhilitti- tic111 t'ilnctioni i4 beyond the scope ol'the preicnt repc~t. a short summary descrip- tion i4 eiienti~~l ~~ndc.~.iti~nding approach. l';~~.ioi~s ot' tl.e;rtnic'nt i~nd rehabilitation i~gencies have appeared in the litc~.ati~r-e, itrld .lone4 ( 1971) :~nalyzed the treatment function in terms of the dift'e~.ent stage\ oftl'c.;~tments that l+el.e typically pro~ided to problem drinkers ;lnd then ileic~.ihed t he I';~cil it iei in\'ol\ ecl in ei~ch sti~gc. Four stages of treatment were defined as l.t\IlO~\ I~~~rorgc~~rc~,~ l'he p~.o~ision intenhilt medicitl care for patients si~ffer- Ing f'l.om ;~c~~te of e~celrsi~e intake and the alcohol ~,ith- d~.:i~r;rl synd~.cjme (deli~.it~m h;tIl~rcinations. etc.). Treatment i~sually re- qui~,es hospit;rli/ation 1'01. tuo or three days. the i~se t~.:tnqi~ilizers, control 01' Huid and clc~t~~olyte I)oto,\.~/ic~trtiotr ('tr~.o: The pro\,ision i)f less intensi~e care to sober up the intoxic;tted pi~ti~nt ;I one- to fo~~l.-cl:~y until the disappearance of such symptom5 as hirngo~c~ the shakes. Treatment inlolves nursing care. tranquil- izers. and an impro~ed diet. Psychological. pyschiatric, or therapeutic treatment niuy begin in thi\ itilge. u hich should result in referrals fur subsequent treatment. Ir~-Pt/tii~tlt '4 wide range of t~.eat~ncnt rehabilitation techniques in it \,i~~.iety settings. Emph:~sis is on long-term treatment such as psychiatric help and 1 ucationi~l training. Its main elements are: I. Itrtot~,si~~c~ c.:ri.cJ: hospititl treatment. 2. C'o~~~~rrli~.vc~c~,rt of nursing en\)ironment. 3, lt~totr.\i~~o for serious surfi~ce symptoms of underlying psy- chose\. 4, I~~di~~itl/ttrl short-term situation counseling or longer behav- ior-modifying therapy admini5tered by :i psychiatrist, psychologist. psy- chiatric soci:rl uorker. or counselor. 5. (;I.O/III /~.v!'c'llot/rct.(~~~j~: therapy in which small groups of patients share expe~.ienccs and problems. 6. Mi1ic.11 tlrc~.tr/~: of the patient in the daily life of the institu- tion as ;I member of it "ther:~peutic community." 7. l)ta/lg rlrc~t.ol~!~: use of drugs to control the symptoms of with- dl-:tw:~l and anxiety or to reduce the desire for alcohol. Drugs such as ALC'OHOL AND HIGHWAY SAFETY 1978 Antabuse are sometimes used for the latter purpose. cai~sing severe (but temporary) physical distress for persons who drink after taking the drug. 8. Al~~oholic*~~ tlse of mutual self-help, among peers. in maintain- ing sobriety: "treatment" provided in small group settings: no medical or psychiatric treatment provided: is not considered a substitute for profes- sional counseling or treatment: many members rely on a spiritual approach (U.S. Department of Health. Education and Welfare 1971 1. 9. Dilllr(.ti(. /~t.o.~ct~t(rtiol~.~: films. and other educational programs on alcohol. 10. Rclrtrhilirrrti~,~ cduct~tion. man~~al exercise. industrial and occupational training. vocational r.ehnbilit;rtion, and job placement. Orlt-Prrticirt Tt.crltinc~trt rriltl A/ioi.c.ot.c: Sel-\/es patients who haie not received treatment as in-patients. kind also serves I'osmel in-patients who need more help in setttsning to the gcnelxl commt~nity. l'herxpy is pro~ided in the form of counsel- ing* c:~sewo~.k, indi\ idual or group psychothe~.:ipy. Suppostive sesidential case is probided in half'-wily hut~scs. where p:~ticnts niay g~~~dually to indepen- dent life. 'The study identified eight nx!ior types of agencies offering the above tseatmcnts: gcnc'ral hospitals. mental hospit;~ls. detoxific:~tion ccnters. alcoholism treatment centers. nient:~l health centers. alcoholisnl clinic.;. psi\:~te tseutment t';~cilitics. and half-way hot~sc+. in\/olvement of' the vir~.iot~s agencieq in the foul stages of tseat- tnent M1ere summiil.ized in the manner shown in Table 5-2. TABLE 5-2 Deto\ific:ition ('enter X Alcoholi5rn Trcalrnent C'cnter Mental Ho\pital X Mental He;~lth ('enter X Alcoholim Clinic Private Trcatrnent Facility X Halfway HOLIW Source: Juscelyn. Maickel. and (ioldcnhnurn 197 1 DEALING WITH THE ALCOHOL-CRASH PROBLEM A later review of treatment modallties for problem drinking-drivers (Joscelyn, Maickel, and Goldenbaum 197 1 ) provided more detailed descriptions of treatments in use c-ircu 1970, recategorizing the treatment techniques into psychotherapy, indirect pharmacotherapy, direct pharmacotherapy, and combination therapy. A more recent review by the Department of Health, Education, and Welfare discusses later develop- ments in treating problem drinkers in general, including various group therapies (e.g., transactional analysis) and motivational theories (U.S. Department of Health, Educa- tion and Welfare 1974). The DHEW report recommends a "social-system" approach. a ccmmunity-oriented program that should "take into account the differences among the patients, as well as the interactions of the several components in the society, and systematically seek to fit the appropriate treatment to each individual." Examples of treatment and rehabilitation programs aimed specifically at problem drinking-drivers are rare in the literature. Most such programs follow an educational approach based on the archetypal Phoenix DWI course. Since its first formal session took place in 1966. the course has served as a prototype for over 400 programs in the U.S. and Canada (Malfetti 1975). Between 1966 and 1973, over 15,000 DWIs completed the course. The course consisted of four sessions at weekly intervals, each session lasting about 2% hours. The basic methods of instruction included informally structured discussion. films, reading materials, and oral and written exercises requiring self-analysis. Each session was conducted by an instructor and attended by probation officers and counse- lors with special training in alcoholism. A magistrate attended the first session only and described the relationship between the court system and the course. The counselors were present in order to assist with referrals to community agencies. Probation officers and counselors participated in discussions. Session 1 focused on the drinking driver and establishing the fact that a problem exists. A homework assignment for participants was the recording of all activities in the 12 hours preceding arrest for DWI. Session 2 focused on the influence of alcohol on driving skills. The goal of Session 3 was to define problem drinking. Each participant assessed his own drinking habits. In Session 4 actions to modify behavior were empha- sized. The outcome of this session was a description by each student of his plans to J.;ddify his behavior. Oral descriptions and discussion preceded an exercise requiring a written description (Stewart and Malfetti 1970). Over 7Wc of the near!: 49,000 persons who entered rehabilitation programs at 26 ASAP sites in 1973 attencied DWI schools (U.S. Department of Transportation 1975a. ch. 5). Twenty-seven percent of the drivers were classified as problem drinkers (prima- rily by Mortimer-Filkens tests or variants of the test) and 45% as social drinkers. The problem drinkers were referred to DWI schools less frequently and to other modes of treatment more frequently than other categories of drinkers. Forty-six percent of prob- lem drinkers entered DWI schools and 5% entered one or more other treatment modes. The most popular nonschool treatment modes for problem drinkers were short term group therapy and Alcoholics Anonymous (17% each). (See Figure 5-4). Long-term treatments (Including Alcoholics Anonymous) were provided by the available commu- nity treatment agencies (i.e., the Alcoholism Control System component of the Drink- ing-Driving Control System). The National Institute on Alcohol Abuse and Alcoholism ALCOHOL AND HIGHWAY SAFETY 1978 Figure 5-4. Use of basic treatment modalities for ASAP problem drinkers in 1973 'j; OF PROBLEM DRINKERS ENTERING REHAB. EXPOSED TO VARIOUS MODALITIES ALCOHOL GROUP CHEMO- IN- INDIV. A A SAFETY THERAPY THERAPY PATIENT THERAPY SCHOOL Source: U.S. Department of Transpurtation 1975a. ch. 5, p. 7 (NIAAA) of the U.S. Department of Health, Education, and Welfare, collaborated with ASAP by providing support to Alcoholism Centers (ACs) designed to extend and im- prove longer-term treatment of problem drinkers at ten ASAP sites (Eagleston, Ritten- house, and Towle 1974). The ACs were oriented toward outpatient care, and most of them had all modalities available, i.e., individual counseling and therapy; group coun- seling and therapy; family counseling and therapy; family services; vocational rehabili- tation; social, occupational, and recreational therapy; and medical maintenance. It was estimated that approximately 37% of all persons convicted of DWI at the ten sites during the period May, 1973. through March, 1974, were treated at the ACs (Eagleston, Rittenhouse, and Towle 1974). 5.3.3 Evaluation ofthe Hcalth Approach Few programs are known to have attempted any kind of formal evaluation of the health approach to drinking-driver control. The first known program to be evaluated occurred at Lackland Air Force Base (Barmack and Payne 1961b). Drinking-driving was characterized as sick, disturbed behavior that could lead to psychiatric evaluation and possible referral for psychotherapy which might result in a recommendation for medical discharge. Following the implementation of this program, lost-time injury accidents declined by more than 50%. After comparing accident history at Lackland with that at another Air Force base in the area and with local. state. and national experience, the researchers concluded that the decline was more likely due to the "countermeasure" rather than to a general downward trend in accidents. - -- _- DEALING WITH THE ALCOHOL-CRASH PROBLEM The only documented evaluation of a health approach program aimed at a more general population of drinking drivers occurred under the ASAP program and its 35 ASAP projects. This program attempted to estimate the effects of its individual health1 legal activities on a wide range of variables thought to be meaningful measures of the program's results. Evaluations were conducted at both the project level (i,e., the indi- vidual ASAP sites) and the program level (i.e., the sum of all sites). The diagnosis and referral functions of ASAP were evaluated with respect to their primary objective of classifying drinkers so that they would receive the most appropri- ate treatment (U.S. Department of Transportation 1975a, ch. 5; Struckman-Johnson 1976). The term "appropriate" was apparently used to describe the available treat- ment that would cause the greatest reduction in an individual's DWI violations and alcohol-related crashes in some future time period. Two criteria were used to deter- mine whether diagnosis and referral were being properly performed. The first crite- rion. termed reliability, was concerned with the consistency of a diagnosis or a refer- ral, that is, whether a given individual would always be classified and referred the same way. The second criterion, called ~~ulidity, with the correctness of a diagno- sis, that is, whether a given individual was properly placed on the social-drinkerlprob- lem-drinker spectrum and, given that placement, referred to the most "appropriate" treatment. Only six ASAP sites submitted data for analyzing the reliability of their diagnostic approaches, and three of those sites were classified by evaluators as having reliable systems (Struckman-Johnson 1976). (See Table 5-3.) Seven out of 14 sites were said to have valid diagnostic systems. The evaluators felt that no unequivocal statement could be made about the reliability or validity of diagnosis for ASAPs as a group. Three out of four reporting sites were said to have reliable referral systems, and two out of eight had valid referral systems. Again. no statement could be made about the reliability or validity of the referral process for ASAP as a whole. Further discussion of the validity of the ASAP diagnosis and referral process may be found in Struckman-Johnson and Mushill (1976). TABLE 5-3 Reliubility and Validity of Diagnosis and Rqferrul Functions ut Reporting ASAP Sites Validity . - -- - - - - - -- - Arrrmhrr Incon- Number lncon- Fun( tlon Nrlmhrr c /11.$11 or Number clusive or Rrlitrhle Unrelitrble Valrd Invalid - - - . - - - -- -- - - -- - - D~agnos~s 3 3 7 7 -- - - - - - -- -- -- - - -- Referral 3 I 6 2 - - - -. - -- -- - - -- Source: Struckman-Johnson 1976 ALCOHOL AND HIGHWAY SAFETY 1978 \ The "bottom line" of the evaluation of ASAP healthllegal applications is the determi- nation of the impact of treatment and rehabilitation activities on the subsequent drink- ing-driving behavior of individuals exposed to the various modalities offered. The DWI schools were the most commonly used modality and have also received the most atten- tion by ASAP evaluators. Seventeen project level evaluations of the school were sum- marized by Ellingstad in 1976 (Ellingstad 1976). The schools were evaluated with re- spect to their effectiveness in influencing accident involvement; re-arrest for DWI; and life changes, knowledge changes, and attitude changes relative to drinking and driving. Of the evaluations which utilized "adequate comparison groups and a statistical com- parison," none showed any positive effects on accident involvement and only one showed a positive effect on re-arrest rate (see Table 5-4, However, six indicated posi- tive effects in increasing knowledge about alcohol-safety, and four had a positive effect in changing attitudes. No relationship between knowledge 01- attitude changes and crashes was reported. No site was found to have induced "life changes" through its DWI school. TABLE 5-4 Reported Rrsirlts oj' ASAP DWI School Effecti~*enrss Which Utilizcd Adequate Compurison Groups clnd Strrtistic,ul Compcrrisons . -- ~ . .. . . . . - .. - . Mcrrs~/ro No. c!f'Siti,s Reporting No. of' Sitos R~porting ~5~f~c~ti1~rncs.r Positi\~o Effi1c.t . - No E1,idenc.e oj'EjYi1c1 - . ~ --- -~ - - Accident Involvement 0 2 Rearrest Rate I 5 Life Changes 0 I Knowledge Change 6 0 Attitude Change 4 0 - Source: Ellingstad 1976 A more recent analysis by Nichols (1977) formed substantially the same conclusions with respect to the effect of ASAP's DWI schools on knowledge, attitudes, re-arrest rate, and crash rate. Nichols also concluded that ASAP's treatment and rehabilitat.on program trs u ~*holo been effective in reducing re-arrest rates of social drinkers referred to the program, but that it had not significantly reduced the re-arrest rates of problem drinkers. The latter finding suggests that the DWI school component of ASAP's treatment and rehabilitation program may have been responsible for the ob- served effect, since social drinkers were not, as a rule, referred to non-school treatment and rehabilitation modes. A rigorous quantitative analysis of the highway safety impact of one ASAP DWI school (Nassau County. N.Y.) was conducted recently by Preusser, Ulmer, and Adams (1976). The analysis was unusual in that the drivers who attended the school were compared with another group of drivers who did not attend the school. Both groups were selected at random from individuals convicted of DWI or DWPI (Driving While DEALING WITH THE ALCOHOL-CRASH PROBLEM Ability Impaired-Alcohol). The stildy found no difference in subsequent DWI or DWAl conviction rates between the two groups and concluded that: . . . . . this program did not meet its objective of reducing the number of repeat convictions for alcohol-related driving events. Further, there is some evidence that those invited to attend the program actually experienced more reported motor vehicle accidents than the control group (p. 104). In summarizing the results of ASAP DWI schools in dealing with the alcohol-crash p~.ohlem. NHTSA concluded that the schools were causing increases in knowledge and positive attitude changes but that "there was not much convincing evidence to indicate that such schools were causing a decrease in arrest or crash involvement for clients exposed to them" (U.S. Department of Transportation 1975a. ch. 5). Research studies of the effects of the Phoenix DW I schools lead to similar conclusions (Crabb et al. 197 1 : Malfetti and Simon 1974). Effectiveness-analyses of varioirs other treatment-oriented modalities employed under ASAP were itlso assessed by Ellingstad in the 1976 study (Ellingstad 1976). The evalua- tions of the ASAP-supported short-term group therapy activities were found to offer "insuificient evidence to eithes support or challenge the efficacy of ASAP administered gr.oup therapy programs." With respect to out-patient treatment (non-ASAP sponsored) as a whole. one site out of three with adequate comparison groups reported a statistically significant decrease in repeat itrrests for DWI, and the one site that analyzed the effect of out-patient treatment on accident involvement did not employ a control group or elimi- nate alternative explanations to support its claim of a positive effect. One of the studies hhowing 1.e-arrest frequency to be unaffected by out-patient treatment used an experi- mental design employing a control group with random assignment. In analyzing the effects of treatment through Alcoholics Anonymous, one site re- ported re-arrest frequency to be significantly lower after seven months of follow-up but found no significant decrease after I8 months. The same site (Los Angeles) also per- formed a rigorous analysis of its chemotherapy (i.e., Antabuse) treatment modality and fo:.lnd a statistically significant decrease in DWI re-arrest rate among the group treated (Ellingstad 1976). NHTSA's conclusion on thc effectiveness of ASAP rehabilitation across treatment modalities was that whilc .onle positive effect might exist, no firm evidence could be offered that rehabilitation was ei'fective in reducing re-arrest and crash involvement (U.S. Department of Transportation 197Sa, ch. 5). It also found that no cor~clusions could be made about the r.oltrti\~~ of the various treatment modalities. Eagleston et al. (Eagleston. Rittenhouse, and Towle 1974) of Stanford Research Insti- tute (SRI) evaluated the ten ASAP Alcoholism Center (AC) projects sponsored by N IAAA. A number of variables were used to measure the effectiveness of the treatment program provided by the Centers. They included several indices and indicators used for making descriptive assessments of client changes; alcohol consumption: impairment in personal, social, and work-related activities: self-esteem: earnings; and re-arrest for DWI. The evaluations were based on comparisons of the following five groups of individuals: ALCOHOL AND HIGHWAY SAFETY 1978 DWls sentenced to probation only (including those receiving a sentence of jail or fine. and those receiving unconditional probation), DWls assigned to DWI school only (although they may also have received a jail sentence or fine), DWls assigned to non-AC treatment (i.e., to treatment at a non-AC facility or agency). DWls assigned to AC treatment, and Non-ASAP referred persons contacting andlor entering ACs. Unfortunately (and as noted in the SRI report) data collection problems plagued the evaluation effort, resulting in non-representat ive data from the ten sites. For example, the reported practices in assigning DWls to various treatments are based on data from only two or three sites, and, in effect. the control group (the combination of groups I and 2 above) was non-existent except for the Tampa, Florida site. In addition much of the data gathered was apparently self-reported by the clients. and is. therefore, subject to the usual limitations of such data. Thus, the general applicability of the evaluation of the various out-patient treatment modalities sponsored by NlAAA is severely limited. The evaluation nevertheless suggests that the ACs had a beneficial effect in reducing alcohol consumption and impairment. More than 92V of its clients reported drinking less than one ounce of alcohol per day six months after intake into the program. However, treatment seemed to have no positive effect in increasing self-esteem or earnings over time. The most effective treatment in reducing drinking seemed to be family counseling, followed by individual therapy. group therapy. group counseling, and medical maintenance in that order. Fragmented data and other constraints prevented any reliable analysis of the effectiveness of the ACs in reducing re-arrests for DWI ( Eagleston, Rittenhouse, and Towle 1974). Other evaluations of treatment and rehabilitation efforts have been mostlj negative. Didenko et al. (Didenko, McEachern, and Berger 1972) compared the driving records of 1306 California DWls who had received six different treatment modalities with the records of 442 DWls who had received no treatment. No significant differences in either subsequent crashes or DWI convictions were found to exist between the two groups. Blumenthal and Ross's study (1975) of 495 convicted DWls in Colorado found no significant differences in the number of subsequent drinking-driving violations or crashes among groups of drivers receiving different punishments and treatments. 5.4 PUBLIC INFORMATION AND EDUCATION APPROACHES Public information and education (PI&E) approaches (called "campaigns"' in the literature) have been used as separate and distinct "countermeasures" and in combina- tion with other approaches. In the following subsections, several examples of PI&E programs are described in terms of their targets, their methods, and their findings. The discussion is preceded by a brief description of some of the theories upon which PI&E approaches are based. LIEALING WITH THE ALC'OHOL-CRASH PROBLEM There are many theories in the alcohol-related PI&E literature, but they are difficult to assess because so few Pl&E campaigns and their underlying theories have been rigorously evaluated. A Canadian review of PI&E literature, (Kates, Peat, Marwick & Co. 1970a) described three theories of behavioral modification in use in this field. The first theory states that information reception can lead to attitudinal change which, in turn. can lead to behavioral change. The second theory sees reception of new informa- tion as leading to behavioral change which, in turn, leads to attitudinal change. The third theory predicts that reception of new information about crashes is a vicarious experience for the recipient. u hich leads to a temporary attitudinal change. The tempo- rary attitudinal change permits the recipient to engage in experimental behavior which tests directly the truth of the information received. If the information received is vali- dated by this informal experiment. long-term attitudinal change may result which, in turn. will lead to long-term behavioral change. Wilde et al. (1971). in a review of current theories and practices in road safety campaigns. stated that psychological research in other areas has shown that many behaviors are controlled bc. certain reinforcement schedules. Behaviors are difficult to influence if they are of long standing, are frequently displayed, and lead to many and immediate advantages for the individual. and when they are strongly interwoven with other habitual behav- iors (p. 38). Hyman and Sheatsley (1947) listed psychological characteristics which affect the impact of public information campaigns as follows: some people remain among the itninformed on all issues, forming a hard core which is relatively impossible to reach; degree of interest in an issue differentially motivates the willingness of people to be exposed to information: prior attitudes affect the degree to which people permit exposure; and prior attitudes result in differential changes in attitudes after exposure. The National Highway Traffic Safety Administration adopted the following standards (discussed by Wilde et al. 1197 I]) for use by the ASAPs which it sponsors: campaign messages must be instrr{~*t 5hould reach the audience in the situation in which decisions about drinking and driving are made (immediacy), should be seen by the recipient as pcr.sonul1.v rc~le,,ant, and should employ a model of the desired brha~lior (U.S. Department of Transportation 1975a, ch. 6). Clearly. the selection of appeals to motivate the target audience is critical to the design of effective PI&E campaigns. It has been theorized (Wilde et al. 197 1) that such appeals should: focus on the human need to avoid anxiety and to fulfill basic physiological and psychological needs; use fear or anxiety appeals only when accompanied by specific directions for alleviating or fulfilling needs; and ALC'OHOL AND HIGHWAY SAFETY 1978 focus on behavior that is observable to all members of the target audience so that it is pohsible that social pressures can be used to reinforce desired behavior. No known studies have attempted to verify any of the above theories when applied in the field of alcohol safety. 5.4.2 Targets of PI&E Can~ptrigns Because there is no proven relationship between exposure to information, attiti~dinal change, and behavioral change, Wilde et al. (1971) advise that PI&E road safety cam- paigns should focus directly on the behavior which is desired. The selection of a target audience for PI&E campaigns should be based on the identification of those who engage more frequently than the general driving population in the target behavior of interest. e.g.. drinking-driving behavior. Target groups may be further defined in terms of their demographic characteristics. types of trips which they make, types of vehicles driven, attitudes about driving etc. (Wilde 1977). The target group should also be defined in terms of its drinking patterns. For ex- ample, though there is evidence that the alcoholic is over-involved in traffic accidents. PI&E campaigns directed toward the alcoholic will be ineffective. Exposure to informa- tion alone has not been shown to be effective in reaching those who may be addicted to alcohol (Wilde et al. 1971). Groups may also be identified by their lack of knowledge of alcohol effects, inexperience with consumption of alcohol or inexperience in driving. Most past alcohol-safety PI&E campaigns have been directed toward the social drinker who may find himself in a situation in which he must decide how much to drink if he has to drive or. having consumed a given amount of alcohol, has to decide whether or not to drive. Few of these campaigns have defined their target groups in much detail. However, two programs are known to have conducted in-depth target analyses of non-crash-involved drivers. and their efforts in this regard are described be.~w. The first of these target definition efforts was conducted in the Vermont ASAP which used mass communications methodology recommended in the 1971 report of the Organi- sation for Economic Cooperation and Development (Wilde et al. 1971). Specifically, the Vermont ASAP used the results of a roadside survey to identify the high risk group, to determine characteristics of risky behavior indulged in by this group, to identify the type of media to which the group was normally exposed, to identify the appeals most likely to influence the group's behavior, and to evaluate the impact of the resulting campaign. The target population defined by the Vermont ASAP consisted of males 16-30 yea1 s of age (45% teenage males) who are beer drinkers, single, divorced or separated; have less than high school educations; work as laborers, operatives, farm workers, in service occupations, or are unemployed; have had one or two traffic citations in the previous three years; go to drive-in movies with other young males; listen to the radio in their cars; look at TV news; read newspapers; and go to auto races. The caveats about driver profiles stated in section 4.0 should be kept in mind when interpreting studies on target groups for PI&E campaigns. Specifically, the fact that a given driver possesses the attributes of a given target group does not necessarily mean that the driver has a high risk of an alcohol-related crash. L)~AL,IIVG WITH THE A LCOHOL-CRASH PROBLEM The data collected in the Vermont survey were also used to identify the knowledge needs of the target population, the appeals which would be most effective, and the media which would most effectively transfer the needed information to the target population. Target audiences defined by thc 35 ASAPs in the U.S. (U.S. Department of Transpor- tation 1975a, ch. 6) have included bar patrons, package store patrons. legislatures, police. physicians, youths, drinking-drivers convicted of DWI. and the general drinking- driving population. The second target definition study was sponsored by NH'TSA and conducted by Grey Adv2rtising (1975). Using a nationwide probability sample, Grey surveyed 1512 adults who were 18-55 years of age and 138 college students during June and July, 1974. This survey was preceded by an "incidenct. study" consisting of a telephone survey of a probability sample of 507 adirlts, 21-60 years of age. The purpose of this initial survey was to establish the frequency with which adult Americans are exposed to social and business situations in which alcoholic beverages are served. Findings of the Grey surveys showed that 54% of adult Americans. 18-55 years of age, participate one or most. times a month in social or business situations in which alcoholic beverages are served. The researchers ebtimate that these situations account hr 87"; of all situations conducive to dsiving after drinking. .4wsrcness of the potential drinking-driving situation was also measured in the Grey stlid\. Fifty-seven perccnt of those who participated in alcohol-related situations (ARS) diu ~iot that they had found themselves in a potential drinking-driving situation. The majority of this group did not know how to tell when others are drunk and didn't know appropriate steps to take when faced with a drinking-driving situation. When action was taken. it involved ciose friends or relatives, whether at home or in public drinking places; and it involved driving the friend or relative home rather than physically re- straining the intoxicated person. The Grey Advertising study also attempted to identify targets in terms of their expo- sure to potential drinking-driving situations and their willingness to engage in effective actions to prevent drinking-driving in those situations. Four groups of individuals were defined with respect to these and other attributes: Q sociul (.o~~fi)rtil('r~ of AKS group, 46% of ARS occasions): males and fem- ales, 20-45 years of age; well educated, higher than average income, white collar occupation; likely tc: !'!t>r to drive intoxicated friend home or to ask him to stay over or to call a taxi if it il considered socially acceptable to do so, serve food hith drinks, are modcr.ately heavy drinkers, can identify the potential DWI situa- tion and take action. crggrrssirqe ~.c.st~.tritlrr.\ (27% of ARS group, 32% of ARS occasions): males. less than 3 years of age, less well-educated than social conformers, less income; reside in the Northeastern U.S.A.; have positive attitudes towards alcohol: know less of alcohol effects, can identify potential DWI situation and take action; one-third find themselves in ARSs two or more times a week; one-half drink most often at home: are heaviest drinkers. prefer beer; friendships and affiliations are Lery important: are willing to use physical restraint with intoxicated friends who decide to drive. ALCOHOL AND HIGHWAY SAFETY 1978 cautious prrplanners (18% of ARS group. 13% of ARS occasions): female, one- third Southern; three-quarters are 35 years or more in age; anticipate and avoid DWI situations, less likely to take action after drinking, have misinformation on alcohol, know a number of problem drinkers; four-fifths drink once a week or less: two-thirds drink 3 or fewer drinks per occasion. (egal enforcers(l2% of ARS group, 9% of ARS occasions): 56% female; 40% are 35 years of age or more: 75% have annual incomes greater than $10,000: 67% have less than a college education; are likely to call police or report bars selling liquor to minors to authorities: have the greatest understanding of the role of problem drinkers in traffic fatalities; 907? are likely to take some action in potential DWI 5ituations. including the use of restraint: are likely to call police if intoxicated person is a problem drinker; are the lightest drinkers of the four groups. Grey Advertising (1975) recommended that alcohol-crash PI&E campaigns should focus on social conformers and aggressive restrainers, since these groups account for both most of the people exposed to alcohol-related situations and for most of the situations. The other groups were found to be too small, but it was stated that care should be taken to avoid alienating them. The objectives recommended include: correction of misinformation about alcohol consumption; identification of potential DWI situations; and persuading people to take appropriate action in potential DWI situations. The Lackland Air Force Base program against drinking and driving (Barmack and Payne 1961b) also used research on characteristics of the target audience in order to develop and plan their countermeasure activities. The 35 ASAPs used both roadside and household surveys to learn more about the drinking-driving patterns and knowledge needs of their target audiences. The findings of the study conducted by G,ey Advertis- ing (described above) were intended for use in the remaining ASAPs in refining definitions of target audiences and in selecting the content of PI&E campaigns (Grey Advertising, Inc. 1975). 5.4.3 Applicutions of' the PI& E Approuch Content of drinking-driving laws has been the focus for most campaigns associated with the introduction of new drinking-driving legislation. The British campaign of 1967 and the 1969 Canadian campaign were both designed to heighten awareness of the public to their rights and obligations under new legislation. The presumptive or per se BAC limit, the procediires for apprehension, arrest and charging of drinking-drivers, and the penalties associated with conviction are the major variables about which factual information was disseminated in these campaigns. Many other information campaigns conducted in the U.S.A., Canada, England and Australia have been run when, though drinking-driving laws were not new, it was determined that the public was poorly informed about the dangers of drinking and driving, had attitudes about the dangers of drinking that were not conducive to the maintenance of safe highways, or were engaging in behavior that contributed to the dangers of drinking and driving. DEALING WIT// THE ALCOHOL-CRASH PROBLEM In at least two campaigns, an attempt was made to change the social value attached to drinking-driving behavior. Development of the Lackland Air Force Base countermea- sure against drinking and driving (Barmack and Payne 1961b) involved the examination of the relevant customs and values concerning consumption of alcohol by airmen sta- tioned at the base. Researchers found that reckless driving after drinking had group tolerance and was seen as courageous and daring. Assigning a different and conflicting value to this behavior was the essential element of the Lackland countermeasure. Reck- less driving after drinking was recharacterized as sick, disturbed behavior. This recha- ractzrization was supported by the establishment of a policy requiring that airmen involved in accidents resulting in loss of duty time of 24 hours or more would be required to undergo psychiatric evaluation and possible referral for psychotherapy, which might lead to a recommendation for medical discharge. Enforcement of this policy was preceded by an educational program to inform airmen of the details of the new policy. Though it u,as not possible to isolate the impact of the educational program from the impact of other. elements of the program. the rate of accidents was reduced. An Australian campaign (1974) against drinking and driving, which began in July 1974. ~~sed approach similar to that used at Lackland Air Force Base. The campaign used the offensive word "SLOB" to describe drinking drivers. The campaign strategy was based on the social sanctioning process. The existing social climate was one in which there were frequent pressures to drink before driving. The impaired or intoxi- cated driver was sometimes treated sympathetically or with amusement. It was assumed that the drivers' desire to avoid a negative label and the resulting shame if it could not be avoided would reduce the number of drinking-drivers, The campaign focused on the susceptibility of the drinking-driver to social definitions of what is considered tasteful or appropriate behavior. (Additional information on this campaign was not available at the time of the publication of the present report.) Both the 1967 British and the 1969 Canadian campaigns also included attitudinal measures which tapped the opinions of the public about the adequacy of the new legislation to prevent or to reduce alcohol-related accidents (Ross 1973; Kates, Peat, Maruick and Co. 1970al. In the U.S.A.. the ASAPs sponsored by the National Highway Traffic Safety Admin- is~rxtion have conducted public information campaigns since 1971 (U.S. Department of Transportation 197Sa, ch. 6). Objectives for these campaigns were defined in terms of waves or phases. The tite of the first wave was to develop an awareness among the public of the dangers and consequences of drinking and driving. In the second wave, attempts were made to personalize the problem by identifying drunk drivers as friends, relatives, and acquaintances in order to counteract the tendency to see the drinking- driver as a deviant. The stimulation of social and peer group concern and the descrip- tion of specific actions which might be taken to cope with drinking drivers were objec- tives of the third wave. The fourth wave focused on specific calls for action. As stated above in Section 5.4.2. on the basis of the 1974 study by Grey Advertising (1975). recommendations for future objectives for ASAP'S PI&E campaigns were: correction of misinformation about alcohol consumption; identification of potential DWI situations: and persuading people to take appropriate action in potential DWI situations. ALCOHOL ANL) HIGHWAY SAFETY 1978 It is not clear that very many actual PI&E campaigns were explicitly based on any given psychological theory. However, the approach of ASAP appears to be consistent with the theory that information reception can lead to attitudinal change which can, in turn, lead to behavioral change. The theory that reception of new information leads to behavioral change followed by attitudinal change seems to underlie the Lackland ex- periment, the Australian "SLOB" campaign, and the British and Canadian campaigns. With respect to audience motivational theories, the Vermont ASAP (Zylman 1973a) found that a mild-fear-of-arrest appeal when combined with the presentation of useful information in a positive fashion (e.g.. how to get home safely without getting caught for DWI) was effective for increasing knowledge. The Lackland AFB experiment and the Australian "SLOB" campaign used the need for social acceptance as a central motivat- ing approach. The information campaign which is used to increase the deterrent effect of legislation also employs the fear-of-arrest approach. However, in such campaigns specifications on how to avoid arrest are not always stated in positive terms. The various ASAPs have used fear, humor, slice of life, and other approaches in their PI&E campaigns. There is little or no sound evidence of the effectiveness of these various approaches for most of the campaigns reviewed. A recent study of materials used in public information campaigns for alcohol-safety found that such materials have become more sophisticated since 1970 (Douglass and Wadleigh 1976). Themes and messages appeared to be aimed more toward specific behaviors and audiences than they had been in early campaigns, and intermediate target groups were being addressed in the more recent campaigns. Fear-arousal themes were found to have been used less frequently than before. Several measures of effectiveness have been used for PI&E campaigns (Wilde 1975): 1, reduction in the presence of alcohol in drivers involved in fatal and other crashes (regardless of fault); 2. overall reduction in average BACs in the road-using public at risk-if this also results in fewer crashes; 3. reduction in those higher BACs considered to be critical in contributory effect on crashes-if this also results in fewer crashes: 4. increase in the public's knowledge of dangers related to driving with high E AC and decrease in negative attitudes toward dangers-if this also results in fewer crashes; and 5, increase in public knowledge of drinking-driving laws, reflected in their ability to recall elements of the information campaign-if this also results in fewer crashes. Measures 4 and 5 are dependent upon the verbal responses of those interviewed, and these responses may not accurately reflect behavioral responses. The conditional phrase associated with measures 2-5 reflects the intermediacy of these measures. The ultimate measure of campaign effectiveness is the change in accident rates upon which measure 1 is based. However. measure 1 is also subject to limitations. Crashes are rare events, DEALING WITH THE ALC'OHOL-C'RASH PROBLEM especially serious crashes. Crashes are subject to marked statistical fluctuations over time and from site to site. Methods and likelihood of reporting crashes vary widely. And environmental (physical and social) factors beyond the control and, sometimes, the knowledge of researchers mav have as great an impact on crash rates as drinking and driving. Haskins (196th; 1968b; 1969: 1970). in his reviews of research on the effectiveness of mass communications safety campaigns, characterizes the model campaign as one which employs: naturalistic communications conditions: a clearly stated cause-effect relationship (this requires use of treatment and con- trol groups and pre- and post-testing); procedures and instruments of measurement which are valid and unobtrusive; and accurate implementation of soundly designed program and evaluation plans. When the measure of campaign effectiveness is reduction in accident rates, few PI&E campaigns provide evidence of effectiveness. In the British and Canadian legislationlin- formation campaigns, there was evidence of ultimate effectiveness. However, because no control gt,oups were used, it is not possible to state with any degree of confidence ttxactiy what role was played by the information campaign. In the Canadian case, there M;!~, also an increase in enforcement activity. so that interpreting the causal f~ctors the short-lived reduction in crash rates is even more problematic in this instance. An excellent evaluation design for determining campaign effectiveness was developed by the Vermont ASAP (Worden, W:iller, and Riley 1975). In geographically dispersed areas, the impact of an education campaign was compared with the impact of an educa- tion campaign used in combination with an enforcement countermeasure. A third condi- tion. in which neither education campaign nor enforcement countermeasure was em- ployed, served as the control for this study. Evaluation and program development and implementation were interdependent activities. Baseline data collected in a roadside survey were used to identify knowledge needs, appropriate appeal tactics, and media. Interim and post measures of effectiveness were also made. Other- examples of alcohol-related safety campaigns in which some attempt was made to proceed in a methodologically sound manner are the Edmonton, Alberta. Canada study (Farmer 1975; Farmer and Stroh 1973) and a study conducted in the Canadian province of Ontario pie:^ : ei al. 1975). In both instances geographically dispersed areas were designated control or treatment cities, and pre- and post-testing of campaign effects were conduc tcd. In reviewing the findings of road safety campaigns in 1971, Wilde et al. (1971) con- cluded that media campaigns cannot bring about behavioral changes and result in few significant attitudinal changes. but that such campaigns can be successful in transferring information. Other reviewers (Swinehart 1972; Swinehart and Grimm 1972) concur in this conclusion. stating that the mass media are not effective in changing attitudes or inducing action. but are good in conveying information. Any alteration of individual drinking-driving habits which results from such campaigns are seen by the reviewer as an unexpected side effect. Examination of the findings of the specific campigns cited in the subsections above reveals the conclusion of Wilde et al. (1971) to be valid. Only in ALCOHOL AND HIGHWAY SAFETY 1978 cases where media campaigns are combined with other types of countermeasures is there significant behavioral change. Thus, the 1967 British case (Sheppard 1968; Ross 1973). the case of the Lackland AFB (Barmack and Payne 1961b). and, to a lesser extent, the 1969 Canadian case (Kates, Peat, Marwick and Co. 1970a) are the three major examples of campaigns hose impact went beyond knowledge gains. The ~nadeqi~acy evaluation design and of other features of campaign development have made it difficult to determine the exact nature and extent of the impact of most alcohollhighway safety media campaigns. Pre- and post-testing is done for almost all campaigns, but very few of them use control groups. Even the British and Canadian cases did not use control groups. Members of the control group used. informally, in the case of the Lackland AFB bere not randomly selected, nor were control group mem- bers matched with members of the treatment group on any basis other than the fact that they were airmen assigned to a base in Texas as were menbers of the treatment group. The Edmonton (Farmer 1975: Farmer and Stroh 1973) and Ontario (Morton et al. 1975: Pierce et al. 1975) media campaigns used control groups which, in each case, were cities selected to match treatment cities in terms of size and of relative isolation from the media of the treatment cities. Both campaigns were successful in transferring factual information about the content4 of drinking-driving laws. The Sidney. Australia, media campaign (Freedman, Hendenon, and Wood 1975) did not use a control group, but did claim statistically significant positive changes in the public's knowledge of the role alcohol consumption plays In crashes. of the legal BAC limit, of penalties associated with DWI conv~ctions, and of the amount of alcohol which can be consumed by the average person before he reaches the legal BAC limit. In the case of the British Road Safety Act of 1967 (Ross 1973). results of public opinion surveys conducted in September 1967 and January 1968, indicated that while only 27% of a random sample of adults knew of the fixed BAC limit before the cam- paign, 39% knew of it after the campaign. The post-campaign survey indicated that 99% of drivers knew that alcohol consumption would be detected by a breath test; 95% knew that refusal could lead to arrests: and 27% correctly described disqualification as a minimum penalty, while 42% described it as a maximum penalty. A much greater proportion of Canadian drivers. 87%. than in the British case, knew that police could give tests for BAC. This percentage increased to 96% after the 1969 media campaign. Many fewer drivers, 35%. knew that even if a driver's BAC were less than .08% wlv (the Canadian legal limit), the driver could be charged with impai, ed driving. This percentage decreased to 31% after the campaign. The proportion of driv~rs who knew that the breath test was compulsory grew from 49%. pre-media campaign, to 87%. post-media campalgn (Kates, Peat. Marwick and Co. 1970a). In many of the campaigns knowledge gains were greater for women than for men (Kates. Peat, Marwick and Co. 1970a; Freedman, Henderson, and Wood 1975; Ross 1 973). In the U.S., the NHTSA sponsored ASAPs (U.S. Department of Transportation 1975a, ch. 6) focused on the following areas in their PI&E campaigns: a awareness of the drunk-driving problem and the relationship between levels of blood alcohol and the risk of a crash; DEALING' WITH THE ALCOHOL-CRASH PROBLEM public's interpretations of alcohol myths; respondent's reported perception of personal responsibility for drinking-driving behavior; and reduction of alcohol-related crashes and resultant death or injury. "In each area of concentration. substantially moie sites with public information activi- ties achieved positive results than sites without an effort" (U.S. Department of Trans- portation 1974a. ch. 6.. p. I). It should be noted that all of the ASAPs conducted other types of countermeasul-es concurrently with the PI&E campaigns and few used more than pre- and post-testing in their evaluation of campaign effectiveness. On most of the twenty-four questions asked on pre- and post-household surveys, both ASAP sites ,t,it/t PI&E campaigns and ASAP sites \tsit/~out such campaigns produced gains in knowledge. However. for each of nine of the questions, 50% or more of ASAP sites 11.itl1 PI&E campaigns produced knowledge gains, and this proportion was, at the same time, greater than the proportion of ASAP sites liithout PI&E campaign that produced such gains. The nine questions focused on the following subjects: fxtors causing the greatest number of automobile accidents: the contribution to accident causation of the social drinker v. the problem drinker: * the contribution to accident causation of the drinking-driver: recognition of the term "blood alcohol level" or "blood alcohol concentration;" the effect of having eaten on the impact of alcohol on the body; recognition of potential DWI situations; subjective probability of apprehension by police when driving under the influence of alcohol; and reported frequence of drinking and driving, a behavioral measure. To conclude, the inadequacy of existing practices in the development and evaluation of PI&E campaigns makes it difficult to determine the impacts of the campaigns on their chosen target audiences. There exists some evidence that PI&E campaigns are effective in bringing about gains in knowledge of drinking-driving laws and in knowledge of the effects of alcohol on the body and on driving skills. There is little evidence to show that PI&E campaigns change either attitudes or behavior. In the few cases in which behavio- ral change, i.e.. reductioi~ in accident rates, especially of alcohol-related accidents, occurred. PI&E campaigns were conducted in conjunction with other countermeasures. In most cases, the impact of the PI&E campaign could not be isolated from the impact of other countermeasures. In the Vermont ASAP, however, it was found that a PI&E campaign, when combined with an enforcement countermeasure, was more successful in effecting knowledge gains than a PI&E campaign used alone, which, in turn, was more successful than the control condition of no PI&E campaign and no enforcement countermeasure. Thus. research does not show that PI&E in general is ineffective, but merely indi- cates that it has not been successful in reducing crashes when used alone. There is evidence that PI&E has been effective in supporting other alcohol-safety approaches, particularly the legal approach. ALCOHOL AND HIGHWAY SAFETY 1978 5.5 TECHNOLOGICAL APPROACHES In the past, specific applications of technology to control of the drinking driver have been limited almost entirely to devices which support the legal and health approaches described in Sections 5.2 and 5.3 of this report. No purely (or even largely) technologi- cal approach has yet been tried, although several have been proposed and studied. This section of the report discusses a type of technology that has had. in its various applica- tions. the greatest impact on the alcohol-crash problem: breath-alcohol analysis. A brief description of some other possible, but untried, applications of technology is also pro- vided here. 5.5.1 Breatlt-Alc.ohol Ano1ysi.v Several excellent reviews ot' the history and state of the art of breath-alcohol analysis have appeared recently (Driessen and Bryk 1973; Harger 1974: Mason and Dubowski 1974: Mason and Dubowski 1976: Moulden and Voas 1975). Mason and Dubowski (1976) traced the science of breath-alcohol analysis back to at least as early as 1847 (in Europe) and found an American paper on the subject published in 1874. Relatively precise measurcments became po~sible in the early 1900s. The purpose of breath-alcohol testing for traffic safety purposes has been to calculate blood alcohol concentrations (BAC) from breath samples. This requires air from deep within the lungs where blood circulates through the pulmonary capillaries. Deep lung air (called "alveolar" air by physiologists) is needed because it is the only type for which brPcrth alcohol concentration can be directly related to blood alcohol concentration through a relatively straightforward application of a rule, known in physics as Henry's Law (AMA Committee on Medicolegal Problems 1970). This law states that the amount of the concentration of a gas in its lic111id phase divided by the concentration of the gas in its gtrsrorrs phase is equal to a constant at a given temperature. In the case of alcohol and blood this constant turns out to be approximately 2100 at 34"C, which means that the amount of alcohol per milliliter of blood is equal to 2100 times the amount of alcohol pel milliliter of hr.eat11. A major problem in developing operationally practical breath testing instruments for alcohol safety applications has been one of meeting the conditions imposed by Henry's Law. The earliest device used extensively in the United States (after passage of the 1939 law in Indiana admitting chemical tests of BAC as evidence) was the Drunkometer which analyzed expired air containing both alveolar air and air not in equilibrium 1 ith the capillary plasma. The analysis was based on the assumption that the fraction of alveolar air in the total sample of mixed air could be estimated by determining the amount of carbon dioxide in the sample. Later studies proved this assumption led to unacceptably inaccurate and variable estimates of BAC, and in 1969 the manual for Federal Highway Safety Programs Standard Number 8 (Alcohol in Relation to Highway Safety) required the use of "substantially alveolar" deep lung air in breath-alcohol analysis (Mason and Dubowski 1976). The reader is referred to Mason and Dubowski (1976) for a detailed discussion of current problems in breath-alcohol analysis. Moulden and Voas (1975) have classified current breath-testing devices according to their application in support of efforts to control the drinking-driver. Six basic classes of instrumentation were defined: DEALING WITH THE ALCOHOL-CRASH PROBLEM Screening Breiith Testers iSBrT), Evidential Breath Testess (EBT), Roadside Collection llevices (RCD). Passive Breath Testes5 (I'BT). Edt~cational Testers. and Alcohol Safety Interlock System\ (ASIS)::' 'The .\c,t.clcnitl~ tc.\tor.\ (SB'rs) are designed for use ir jurisdictions that permit a police officer to check :I driver's BAC prior to arrest, thus providing additional and mo1.e rcli~ible infosniation than tsaditional "field tests" for determining if an arrest shot11d be m~ide. SBTs collect expired air in a rubber balloon or some similar dc~icc pjiss the air over :in alcohol-sensitive chemic:il. Electromechanical SBTs are ,m:ill. ~~ei~sable ~tbout the size of a transister radio and employ several differ- ent tcchniqires for hensing and measusing thc amount of alcohol in a sample. The I i .S. Department of Transportation hiis field tested several types of electrome- c.ti:rnic:ii SBTs in four states that habe enacted appropriate legislation. It found that in onc j~rrisdiction nearly half of the driver-s tested indicated BACs of greater than .10% \~'v stated that most of' these individuals would have been released without tests hcc;iirse they ueve not obviously intoxicated. Asrest rates of the SBT-equipped p:itrols inc~cii~cd in one year, compared to ;in increase of only 23% for the patrols with no SH'I'). k'usther.. the :iveriige HAC of tr~.t~o.\to(l decreased from . IX(;4 wlv to . 141% ulv uhen the SHTh were trsed (Moulden and Voits 1975). i.:~.irlotrtitrl hl.c~or11 to\to~..\ iEf3'rs) Lire more accur~tte and reliable than SBTs sxnce, as the name suggests. their results mu41 be adrniscahle in court as evidence. Three basic type\ i1r.e in use. G;is chroni;itogr~aphy EBTA determine the presence of alcohol in a sample by measusing the time required for the alcohol molecules to pass through a "chr~omiitogr;~phic" Photometric EBTs measure color changes caused by iilco- hol passing through an indicator solution. Infrared EBTs pass an infrared beam through ;I breath sample and measure the change in energy transmittance caused by the alcohol. It is interesting thiit. although EBTs have been used operationally for nearly 30 years, no formal evaluation of their effectiveness in supporting legal and healthilegal objectives t8:l\ been made. They :ire now ~irch :in integral part of both approaches that it seems doirbtful that any me~iningful e\iiiluation could be performed. Rotrd,sitle c~olloc~tion ( RCIIs) are used to collect breath samples for later analy- si5 by EBTs. thus simplit') 1r.y the processing of DWls by police officers. The samples i1r.e collected either directly as :i volume of breath in a special container or by absorp- tion of the alcohol in w silicii gel, Mason and Dubow~ki ( 1976) have tabulated the results of 28 studies of the correlation between the RACs obt21ined indirectly from breath-alcohol tests and BACs obtained directly from nearly simultaneoi~s blood-alcohol tests (see 'Table 5-5). Nine different instruments, dating back to an improved version of the Drunkometer in 1956, were comparecl. The data indicate that the heath-testers typically underestimate BACs deter- The ASlS cc)ncc.pl i\ no longer hcinp congidered hy NHTSA. It has been replaced by the Drunk Driver W, ,II . nlng Syjtcm (DIIU'S). ALCOHOL AND HIGHWAY SAFETY 1978 mined from blood analysis by up to 10% or so. Thus. a BAC reading of say .lo% wlv from a breath tester would generally correspond to a reading of ,1092 ulv to .I IClc wlv from a blood tester. TABLE 5-5 BloodIBrouth Corrrlrrrion.\ Foctnd in 28 Stcidic~.\ 11,ith Nine Breath-Tc.~tinl: (19.56-1974) Drunkometer. rebreathed air Breat ha1 y zer@ AlcometerB Breathalyzer@ Breathalyzer' Breathalyzer@ Breathalyzer@ Breathalyzer@ Kitagawa-Wright Hermes syytem Drunkometer, rc- breathed air, arterial blood Breathalyzer0 vs blood Breathalyzer@ vs playma Breathalyzer@ G. C. Alco-Analyzer Alco-Tector G. C. Intoximeter@ Breathalyzer@ Breathalyzer@, re- breathed air Alcolinger Automatic Intoxilyzer Breathalyzer@ Breathalyzer@ G. C. Alco Analyzer G. C. Intoximeter@ G. C. Intoximeter@ direct analysis G. C. Intoximeter@ indium capsules lntoxilyzer G. C. Intoximeter@ Tomparisons in which the blood alcohol was less than 0.05% wlv are omitted. hData calculated from estimates made from scatter diagrams. Source: Mason and Dubowski 1976. p. 16 DEALING WITH 1HE ALCOHOL-CRASH PROBLEM The remaining three classes of breath testers have not yet been used operationally. Pnssi,,r brecrth testing devices (now called noncooperctti\~e hreutll testers) might help overcome the objection that pre-arrest breath testing is self-incriminating or constitutes illegal search or seizure. They would make a qualitative determination of breath-alcohol by "sniffing" the air around the driver and would not require the driver's cooperation. Edl~c,c~tiotlal (now called self testers) would be used by drivers to test their own breaths to determine if their BACs had reached levels indicating impairment. They could be low-cost, individual, disposable devices that could be distributed by liquor stores, schools, etc., or reusable self-breath testers that could be installed in bars, restaurants, etc. Tltr Drunk Dri~ser. Wtrrning Sysr~m has superseded the Alcohol Safety Inter- lock System (ASIS) at NHTSA. ASlS would prevent a driver from starting his car if his BAC were too high. The DDWS concept now being studied would allow the impaired driver to start his car, but would cause his lights to flash at speeds of less than 10 mph and his horn to sound intermittently at speeds above 10 mph. One way of activating the DDWS would be the drives's failure to perform a critical tracking task (CTT) which would require him to keep a needle in the center of a display by turning the steering wheel. A possible use of the DDWS would be to install it on the cars of convicted DWIs as a condition of probation. Again, neither the non-cooperative breath tester, the self tester, nor the drunk driver warning system has yet been demonstrated to be feasible for use in drinking-driving control programs (Moulden and Voas 1975). Ranges of cost-benefit ratios for several such devices were estimated by Moore et al. (1976) and presented as a function of such parameters as deterrent effect, usage rate, etc. 3.5.2 Other Technology-Oric~rztl~d Concepts Devices other than the CTT tester have been suggested for assessing alcohol impair- ment (Voas 1970). Devices that measure the driver's BAC directly were considered first, but are receiving little attention today because of the ease with which they can be defeated. A second class of devices would measure a driver's ability to perform tasks related to driving or thought to be critical in avoiding crashes. This class includes devices that would measure reaction time, coordination, steadiness, proficiency at di- vided attention tasks, and short-term memory. Such devices have been built and tested, but have not been placed Ir general use (Moulden and Voas 1975). Any of the above devices for a,,sessing impairment could be used in conjunction with other devices which might prevent an impaired driver from starting his car (e.g., ASIS) or warn other drivers of the presence of impaired drivers (e.g.. DDWS, see above discussion). Such devices might incorporate a feature that would require a driver to insert his driver's license or other identification into a reading device as a condition for passing the impairment test (Voas 1970). It has also been suggested that driving performance be continuously monitored for clues that would betray alcohol impairment (Voas 1970; Moore et al. 1976). When the continuous monitoring device indicated unacceptably high impairment, a warning signal would be given (e.g., a flashing light) or a speed governor would be activated. A similar system has been designed to prevent truck drivers from falling asleep. It measures - -. - -. ' -. ALCOHOL AND HIGHWAY SAFETY 1978 steering wheel reversals and sounds an alarm when the driver's steering performance falls below some critical level. It is conceivable that a mechanical or electronic device could be built to restrict a convicted DWI to driving only during certain specified hours. The device could use a light sensor or timing mechanism either to activate an interlock or to give a warning signal if the vehicle were being driven during restricted (e.g., nighttime) hours. Alterna- tively, an operating time recorder could be used to indicate if the vehicle had been driven during restricted hours (Moore et al. 1976). An application of pharmacological technology has been studied as a means for reduc: ing the impairing effects of alcohol. Several drugs for blocking the effects of alcohol on the central nervous system have been tested in the search for such a "sobering pill" (Noble 1974). One drug, L-dopa, had a statistically significant effect on improving the subjects' performance on a divided attention task, but induced unpleasant side effects (i.e., nausea and vomiting). Research is continuing, but no practical drug for canceling the effects of alcohol has yet been discovered. Analysis of the various technological concepts outlined in this subsection (5.5.2) indicates substantial problems in using any of them in any operational programs to reduce alcohol-related crashes. In some cases (e.g.. the sobering pill), feasibility has not been demonstrated. Devices to prevent a drunk driver from starting his car face sub- stantial public acceptability problems and are no longer being considered by NHTSA. The drinking driver may decide not to use the self tester and the cost of self testers may be too high for practical use. Continuous monitoring devices could cause rather than prevent crashes if their warning signals were to startle or upset drivers. All of these devices would run the risk of being defeated by ingenious drivers and could present substantial legal problems. None appears to be a panacea in itself, but would have to be used in combination with or in support of other approaches (Voas 1970). - - -- 5.6 THE SYSTEMS APPROACH The term systems approach, appears to have been introduced in the early 1950s to describe techniques being developed for managing large and complex aerospace pro- jects (Jones and Joscelyn 1976). Its most essential distinguishing feature is its concentra- tion on the whole problem rather than on its component parts. One of its most success- ful practitioners, Simon Ramo, described it as follows: It is an approach that insists upon looking at a problem in its entirety, taking into account all the facets, all the intertwined parameters. It is a process for understanding how they interact with one another and how these factors can be brought into proper relationship for the optimum solution of the problem. The systems approach relates the technology to the need, the social to the technological aspects; indeed, it starts by insisting on a clear understanding of exactly what the problem is and of the goals that should dominate the solution and lead to the criteria for evaluating alternative ave- nues. As the end result, the approach seeks to work out a detailed description of a specified combination of men and machines-with such concomitant assignment of function, designated use of material, and pattern of information flow that the whole DEALING WITH THE ALCOHOL-CRASH PROBLEM system represents a compatible, optimum, interconnected ensemble for achieving the performance desired (Ramo 197 1, p. 1 1 ). The systems approach has also been described as "a way of thinking about manage- ment," providing the means for arriving at the best solution to a problem through a methodical process of identification and control of its interrelated parts (Morse 1966). Rather than breaking down a problem into small pieces and solving each one indepen- dently, the systems approach attempts to address the total problem by tracing the effect of a choice or decision upon each element of a problem, and. ultimately, upon the whole problem. Some writers have proposed that the systems approach be applied to those societal problems which are more concerned with the activities and interrelationships of human beings than with the primarily technological problem. One of the first writers to suggest what amounted to a systems approach to societal problems was Sir Julian Huxley, the biologist, who perceived the evolution of a societal "brain" having a greatly increased capability for obtaining information and for planning, correlating, and flexibly con- trolling the execution of social programs (Jones and Joscelyn 1976). Simon Ramo (1971) proposed the application of the more specific tools of the aerospace systems approach as a "cure for chaos," resulting eventually in the dawning of a "golden age" when "the full application of logic, objectivity, and all the facets of science and technology (are used to) get solutions to society's problems . . . . . . 3 , The first documented application of the systems approach to the alcohol-crash prob- lem was the Joscelyn and Jones analysis of the so-called Drinking Driver Control System (Joscelyn and Jones 1971). The study used the functional analysis technique (a basic tool of the aerospace systems approach) in conjunction with standard research methods from the social sciences (e.g., survey research) to develop statements about the implicit objectives, functions, requirements, and operational modes of that " sys- tem." Rough estimates of the values of some of the variables which describe the performance and effectiveness of the system were made, and each major function was examined to determine its deficiencies and their impact on other functions and the sys!:m as a whole. A lack of conscious management of this complex system was apparent and the study recommended, among other things, that "management offices be established on the local, st~te, national levels to assist in the development and application of the concept 0.' the DWI Control System as a system, i.e., System Man- agement Offices." The study concluded that the systems approach offered "a new and potentially very valuable method of handling a problem which has, until now, proven intractable." In 1%9 the National Highway Safety Bureau (later the National Highway Traffic Safety Administration) of the U.S. Department of Transportation announced a nation- wide Alcohol Safety Action Project (ASAP) and established an Office of Alcohol Coun- termeasures to manage it. The program provided financial assistance to and coordinated the efforts of, at first, nine and, ultimately 35, individual ASAPs around the country. From the beginning ASAP embraced the systems approach, declaring that "In planning and managing an ASAP, the project director will need to use the systems approach, in order to properly integrate all of the complex aspects involved. He should consider the ALCOHOL AND HIGHWAY SAFETY 1978 project as a whole system made up of several subsystems which are related to and dependent upon each other. The project director must take these relationships and dependencies into consideration in order to maintain proper balance in the operation of the subsystems" (McKnight, Adams. and Personeus 197 1 ). No other alcohol safety program of comparable scope, depth, and size has attempted the systems approach to the degree employed in ASAP, although some jurisdictions have applied and are continuing to apply some of its concepts on their own. For this reason, the remainder of the discussion of the systems approach to drinking-driver control will be limited to ASAP. Emphasis is given to those aspects most relevant to the systems concept, rather than to the individual "countermeasures" which were dis- cussed previously in this report to illustrate other approaches. 5.6.1 ASAP Targets As noted previously in this report, ASAP was heavily oriented toward the problem drinking-driver who, it claimed, is responsible for two-thirds of the alcohol-involved traffic fatalities in the U.S. and 34% of all traffic fatalities. These figures could not be justified by the authors of this report. The figures were apparently derived from DOTS 1968 report Alcohol and Higl~rt,ay Saj'ety (U .S. Department of Transportation 1968) and have been depicted graphically in a chart which has appeared in numerous ASAP reports over the past several years (e.g., U.S. Department of Transportation 1974a; Voas 1975b). The chart also presents data from a 1971 DHEW report (U.S. Department of Health, Education and Welfare 1971) showing 21% of all American males to be "heavy" drinkers (defined as a person who drinks nearly every day, with five or more drinks per occasion at least once in a while: or uho drinks about once weekly with usually five or more drinks per occasion). One-third of these heavy drinkel ; (7% of all males) were said to be problem drinking-drivers who could only be rehabilitated by a safety program, and two-thirds were heavy social-drinking drivers who could be de- rrrrc~d by a safety program (see Figure 5-5). ASAP program personnel have cautioned against making an oversimplified distinction between problem drinking-drivers and social drinking-drivers, noting that drinking pat- terns vary over a continuum ranging from complete abstention at one end to alcoholism at the other (Voas 1975b). They, nevertheless, believed it useful to distinguish betwren problem drinkers who must drastically change a behavior over which they have little or no control. and social drinkers who need to make only a relatively minor change in their behavior. ASAP also placed emphasis on drinking drivers who drive at night and on weekends, drawing upon research which has indicated an increased incidence of alcohol-impaired drivers using the roads and involved in crashes at such times. This policy was imple- mented at most ASAP sites by fielding more police units (e.g., an enforcement task force) during the hours between 6 P.M. 4A.M., Wednesday through Saturday (U.S. Department of Transportation 1975a, ch. 2). Some ASAPs designed their enforcement efforts to intercept intoxicated drivers on main thoroughfares connecting drinking estab- lishments with residential neighborhoods, and a few sites concentrated on areas having high rates of alcohol-related crashes. DEALING WITH THE ALCOHOL-CRASH PROBLEM Figure 5-5. Alcohol Safety Action Program Concept 3-6.2 The ASAP Pro~rum The national ASAP program was an outgrowth of the Highway Safety Act of 1966, which required the Secretary of the U.S. Department of Transportation to study the relationship between alcohol and highway safety and to report the results and recommen- dations of the study to Congress (U.S. Congress 1966). The result was the 1968 report Alcohol and Highwuy Safety, which described a serious national alcohol-crash problem. On July 22, 1969. the Secretary of U.S. Department of Transportation announced a comprehensive countermeasure program to deal with that problem, and shortly there- airer, an Office of Alcohol Countermeasures (OAC) was established within the National Highway Safety Bureau (NHSB) (U .S. Department of Transportation 1970b). The NHSB's Alcohol S;lr"ety Program was to encompass three major areas, identified by the acronym IDA: Identification, Decision. and Action. First, it was to develop and implement measures for identifying problem drinkers on the roads (i.e., through en- forcement), from court records, from the records of health and social agencies, and from driver improvement courses. Next, the information identifying problem drinkers was to be used in decision-making about the nature and treatment of the drinking problem which led to drunk-driving. Finally, action would'be taken to prevent future drinking-driving. Such actions would include both punitive measures and treatment of the drinking problem. and the nature of the actions would depend on the individual driver and available alternatives (U.S. Department of Transportation 1970a). The ASAP program was established within OAC as a part of the overall IDA concept. Its ultimate goal was to "demonstrate and evaluate the feasibility, methodology, and I "Dt.TL.R" I'HE "CONTROL." THE HEAVY SOCIAL PROBLEM DRINKER DRINKER - POLICE - COCRTS 144 OC DRIVb.RS - 74 OF DRIVERS INVOI.VED IN 1- INVOLVED IN 113 OF .1tR 213 OF AIR FATAI. CRASHES C-- FATAL CRASHES f-- I ! - PL'BLIC C---- REHABILITATION 1 EDUCATION Source: Voa9 197Sb. p. 34 ALCOHOL AND HIGHWAY SAFETY 1978 impact of comprehensive, multifaceted countermeasure programs designed to reduce the incidence of alcohol as a causal factor in motor vehicle crashes" (Crittenden 1970). It also sought to evaluate systems and procedures for dealing with the problem drinking- driver and had the following specific objectives: to stimulate implementation by states and communities of successful countermea- sure programs; to provide visibility to the alcohol-crash problem and generate public support for more effective action at all levels of government; to study the effect of countermeasures applied individually and in combination on crash reduction; to evaluate cost v, effect of specific countermeasures and countermeasure combi- nations in order to establish a valid basis for resource allocation; and to document the legal, administrative, and political problems associated with countermeasure implementation (Crittenden 1970). Individual ASAP projects were to be conducted at the local level, emphasizing im- proved law enforcement, traffic court procedures, public information, and special ef- forts to counsel and assist drivers. The local activities were to be complemented by state-level efforts in driver licensing, motor vehicle registration. traffic records and legislation. Each project would be supported by about $500,000 a year in federal funds provided to a state or local governmental agency which would act as a prime contractor to the NHSB. Federal funding support would continue for three to four years after which it was hoped that full state or local funding would be provided to continue each successful project (Crittenden 1970). The NHSB would also assist the local ASAPs by providing technical assistance, by training of ASAP personnel, and by helping to de- velop an evaluation methodology. The first group of nine ASAPs began operation in 1971 (see Figure 5-6). "wenty-six additional ASAPs initiated operations in 1972. The locations were widely distributed around the U.S. and included one site in Puerto Rico (see Figure 5-7). ASAP used a combination of the legal, health, public information and education, and technological approaches in its attack on the alcohol-crash problem. It used the term "countermeasure" to describe a separate action against the "threat" imposed by the drinking driver, terms that were drawn from the aerospace and defense sectors which originated its systems approach. Eventually, five separate categories of countermeasure activities evolved (U.S. Department of Transportation 1975a): @ Enforcement, Judicial and Legislative, Presentence Investigation and Probation, Rehabilitation, and Public Information and Education. The level of activity in the various countermeasure areas is indicated by Figure 5-8, which shows planned federal expenditures for the 35 sites. The fact that the program was a demonstration effort rather than operational is indicated by the relatively large administration and evaluation components which were required to analyze and docu- ment progress and results. DEALING WITH THE ALCOHOL-CRASH PROBLEM Figure 5-6 Operational phasing of the Alcohol Safety Action Projects SITE SELECTION AND PROPOSAL DEVELOPMENT PROJECT INITIATION APPLICATION PHASE PHASE PHASE OPERATIONAL FINAL Rfti ~c'itlr BACs of' .lo% II~/V Licensed Male Drivers in 197.5 TOTAL POPULATION 16 YEARS OLD AND OLDER , 1 I I 1 1 I A,qr 16- I9 20-24 25-29 30-34 35-39 40-44 45-54 55-64 65-up Total 1940 1950 IW 1970 1980 1990 YEAR -- - - - Mule Lic,rnsrd Dri~~rrs, . - - 9.4 13.6 12.3 9.9 8.1 7.8 16.2 12.5 10.3 - 100.1 - 'Based on data from Filkins et al. 1970, Perrine, Waller. and Harris 1971; Waller et al. 1970 'Based on data from U.S. Department of Commerce 1975, U.S. Department of Transportation 1975b FUTURE L)IRECTIONS OF THE ALCOHOL-CRASH PROBLEM Figure 6-4. Targets of past approaches to the alcohol-crash problem FACTORS HIGHWAY FACTORS The Grey Advertising survey (1975) conducted in 1975 (see Section 5.4.2) is an example of one of the more recent efforts to define target audiences in a systematic and exhaustive manner. Fifty-four percent of adult Americans, 18-55 years of age, were found to participate one or more times a month in social or business situations in which alcoholic beverages are served. If, in fact, as the researchers claim, these situations account for 87% of all situations which could result in pressures to drive after drinking, the resulting definition$ of target populations for alcohol-crash-related PI&E campaigns represent a step forward in the processes of target identification and selection. bven more indirect target groups consisting of persons who manage and operate agencies that interact with drinking drivers should also be considered in future pro- grams. The ASAP progr-: i !)as addressed some of these groups (e.g., Traffic Law System personnel. including prosecutors, judges, probation personnel, and legislators) through "training" programs in alcohol safety, but a much wider spectrum of institu- tions and organizations (e.g., the health care delivery system, insurance companies, automobile manufacturers, highway designers) could be the targets of future actions. Voas (1974) has suggested that detailed "models" of the drinking-driving "process" be developed to aid in identifying productive points for interdicting the series of events that culminates in alcohol-related crashes losses. Such a model could be of even greater breadth and depth than indicated by Voas in his illustrative example (see Figure 6-5), taking into account each significant activity that must be performed and each important decision point in the process (e.g., acquiring alcohol, starting a car, etc). Further, the model need not be limited to the pre-crash phase but should be extended to cover ALC'OHOL AND HIGHWAY SAFETY I978 elements of the crash phase and post-crash phase unique to or especially important to drunk driving (e.g., protecting occupants who do not take actions to protect themselves, emergency medical services for single-vehicle crashes occurring in the early morning hours). Finally, future responses to the alcohol-crash problem should systematically search the wide range of human, vehicle, and highway environmental factors related to such crashes for targets more vulnerable to applications of current knowledge and technol- ogy. Key factors and situations that reinforce or inhibit driving after drinking should be listed and cataloged, and specific elements of driving performance that are degraded by alcohol should be identified and described. With respect to the vehicle and driver-vehi- cle interactions, design characteristics critical to alcohol safety should be studied to identify high priority targets. For example. vehicle handling, and the feedback of perfor- mance information to the driver (and other drivers) might be fruitful target areas for technological approaches. Similar opportunities exist in improving the interactions be- tween the driver, the vehicle. and the highway environment through improved highway design, more effective signs, and the removal of hazardous obstacles from the roadside. Obviously, such improvements would benefit all drivers, alcohol-impaired or not, but they would be particularly beneficial in dealing with drunk drivers. A more methodical and comprehensive approach to the definition of targets for future alcohol-safety efforts seems essential to reduce significantly the level of alcohol-related crash losses projected for the 1980's. In the short-term future, it is crucial that the problem be attacked at points that will prove the most vulnerable to current technology. and more innovative long-term responses will require the identification of new targets and new modes of attack. Reassessment and reformulation of the targets of alcohol-safety programs as sug- gested in the preceding section should help in getting better results from future pro- grams, but key issues related to the philosophy and design of such programs will have to be resolved before really substantial progress can be made. The plain fact is that past efforts have not made much of an imprint on the alcohol-crash problem, and it seems likely that this is more due to the lack of an adequate foundation for many of the approaches that have been adopted, than to improper application of well-underst od principles. The leg01 approach is the oldest and most widespread response to the problem. 1~s basic tenet is that the threat of punishment will deter people from drinking-driving. Most researchers (Zimring and Hawkins 1973; Buikhuisen 1972b) who have studied the theory of deterrence agree that the primary factors related to its successful application are (I) the characteristics of the target population group, (2) the nature and motivations of the behavior to be prevented, (3) the target population's awareness that a deterrent threat exists, and (4) the credibility of the threat to the target population (see Section 5.2.1). Scholarly discussions of these four factors are abundant in the literature, but the fundamental questions of interest to designers of alcohol-safety programs remain un- answered, namely: FUTURE DIRECTIONS OF THE ALCOHOL-('RASH PROLI1,EM ALCOHOL AN11 HIGHWAY SAFETY 1978 What specific variables are sufficient to describe target population groups and drinking-driving behavior for operational purposes? What essential information must be communicated to the target population in what way to achieve an adequate level of awareness that a deterrent threat exists? What is the nature of the deterrent threat that will achieve a given level of deterrence among a suitably defined and informed target population? The last question is particularly germane to the future of the legal approach. It generates two other very basic. but also unanswered questions, i.e.: What must the probability of detection and apprehension be? How much of what kinds of punishment should be involved? Operationally useful answers must be given to all of the above questions to support the development of more effective legal approaches to the alcohol-crash problem.* In seek- ing such answers, it may be appropriate to regard law as a hypothesis, as suggested by Reese et al. ( 1974): If law is regarded as involving the assumption that certain consequences will follow from its enactment; then its application should be regarded as a test of its validity. The results of these tests should be used to modify or support the initial hypothesis (p. A-6). Revision of past legal hypotheses on deterrence of drinking drivers is clearly in order, given the results of the programs that have attempted to apply the hypotheses. Further, in view of the relative insensitivity of alcohol-related crash losses to past levels of legal approach activity, it appears that rather substantial revisions may be required, for example, increasing apprehension rates by a factor of 10, or more. Findin, practical ways of achieving these large changes without violating fundamental human rights and without offending citizens will obviously be a great challenge to researchers and pro- gram designers. The h'crlth rrpprorrcah has relied on the legal approach as a case finder for drinking drivers needing treatment for a drinking problem they are unable to control. Thus, any improvement in the detection and apprehension capability of the enforcement compo- nent of the legal approach should benefit the health approach as well. More sharplll- focused case-finding methods for identifying target groups of problem drinking drivers (including methods not dependent on the Traffic Law Systems) would also be helpful, as would more efficient and reliable ways of diagnosing and referring patients to treatment. However, the most fundamental barrier to successful application of the health approach is the lack of effective treatment modalities for the drivers who have been identified as problem drinkers. No treatment or rehabilitation technique has been shown to reduce crash losses measurably. Thus. an approach that has correctly identified what ought to be done (i.e., to treat rather than to punish) may have failed because it could not be NHTSA has recently initiated a program of research on general deterrence as applied to the alcohol-crash problem. A thorough analysis of the British Road Safety Act of 1967 is planned as a p, rt of this program. FIJTORE DlRECTlONS OF THE ALCOHOL-CRASH PROBLEM realistically implemented. The rtate of the art of identifying and "processing" problem drinking drivers is sufficiently developed to deliver large numbers of patients to treat- ment; but existing treatment modalities have little demonstrated effectiveness. Clearly, the priority item for improving the overall effectiveness of the health approach is the development of treatment modes that work. Lacking these improvements, the health approach will play a minor role in dealing with the alcohol-crash problem of the future. The public information and education (PI&E) approach has tried to improve knowledge, attitudes. and behaviors associated with drinking driving. Its most wide- spread use has been in support of the legal approach where it has been used in an attempt to increase the public's perception of the risk of apprehension for drunk driving. In one application (the British Road Safety Act of 1967) it was believed to have played a major role in achieving a large (but short-lived) decrease in alcohol- related crash losses. This particular combination of legal and PI&E approaches is one of the few alcohol "countermeasures" that have worked. Important questions remain- ing unanswered are: why it worked in the British application, and under what condi- tlons it would work as well or better in other settings. Specifically, we need to know and understand the key ingredients for using PI&E as an effective instrument for modifying drinking-driving behavior. When this is known, then other applications of PI&E not dependent on the legal system may become possible, for example, the use of intermediate population groups to influence drinking drivers, as suggested in the preceding section. It seems paradoxical that in a technological society such as our own so little attention has been given to tec-hnologiccil crpprouc'hrs to the alcohol-crash problem. This is per- haps less due to the inavailability of the technology per se, than to the lack of under- standing of how to apply it to such a complex societal problem. For example, it appears likely that a drunk driver warning system (DDWS) could be developed for operational use in the next few years. However, such a device would probably be too expensive for installation on all cars (at least in the immediate future), requiring that it be installed only on cars used by problem drinkers. This would require (as in the case of the legal and health approaches) that the problem drinkers be identified and that the legal author- itv and process for requiring the installation of the devices be defined. After a DDWS device was installed on a driver's own car, means for preventing his use of other cars would still have to be provided. On the other hand. othct dr~vers example, a wife or a neighbor) might need to use a car with a DDWS. and provisions might have to be made to permit such usage without requiring the driver to provide a breath sample or to pass a performance test. Conceiva- bly. such a device could malfunction or a non-intoxicated person faced with an emer- gency might fail the test and be exposed to a greater risk than drunk driving. In such cases, who would be liable for any losses suffered? These and other questions will need to be resolved before the full potential of the technological approach can be realized. In the meantime, technological solution to the alcohol-crash problem will probably be more effective when used in conjunction with other approaches, for example, with a legal approach for identifying high-risk drinking drivers. Efforts to develop this technology should be continued, with the expectation that many of the present constraints affecting operational usage will be relaxed, for ALCOHOL AND HIGHWAY SAFETY 1978 example, cost, reliability, maintainability, and ability to discriminate the alcohol-im- paired drivers from other drivers. Among the approaches that have been tried to date, the systems approuch appears to offer the best hope of conquering a problem as multi-faceted and pervasive as drinking- driving. The full potential of this approach will begin to be realized when it is used as a tool for system design and engineering rather than only for system management as was the case in the ASAP program. Powerful methodologies and techniques are available for developing optimal designs of total systems and have only begun to be applied to the alcohol-crash problem (Joscelyn and Jones 1972). They should now be used to develop new configurations of drinking driver control systems derived by optimal application of current knowledge and technology to the generic functions that must be performed to minimize drunk-driving crash losses. At the same time, it must be realized that the systems approach is not a panacea or even a "countermeasure" in itself, but merely an orderly way of applying what is known to accomplish a specific set of objectives. Thus, it is ultimately limited by the "current state of knowledge" in the many disciplines that relate to the alcohol-crash problem. The systems approach cannot specify what will cure problem drinking any more than it can describe the nucleus of an atom, but it can, for example, help in incorporating known treatment methods into an overall alcohol-saf- ety program. Other approaches (and individual countermeasures) than the five noted above have been suggested and, in some cases, even implemented on a limited scale. These range from various ways of restricting the use of alcohol (e.g., raising the legal drinking age) to imposing insurance rate increases on persons convicted for DWI to impounding the vehicles of drunk drivers (Driessen and Bryk 1973). Many others will become apparent after a comprehensive analysis of potential targets as suggested in the preceding sec- tion. Further research and, where indicated, testing of new concepts shol~ld be sup- ported. At the same time, it should be remembered that these concepts will remain hypotheses until they have been validated and refined for operational usage. Premature adoption of' rlnprorlen appro(rc*hus ill neurly al~vuys be counterproductir~e and shorrld he crrqoided in denling ~ith alctohol-crasil problem of the future. 6.2.3 E\,rrlucrtion Evaluation of both new and on-going programs is a key ingredient to future progress in alcohol-safety. Without it, past misconceptions and mistakes will be perpetuatdd: with it, successful techniques can be identified, further improved, and diffused to other users. There are few examples of careful evaluations of alcohol-safety programs before ASAP. When programs or "countermeasures" were evaluated, this was done with rigor insufficient to provide a reliable basis for decision making on future programs. ASAP'S great contribution to the field of alcohol safety was to test and evaluate on a large scale and for the first time many widely held hypotheses about how to decrease alcohol- related crash losses. Even so, ASAP has fallen short of meeting what some evaluation specialists believe are minimal requirements for evaluating social programs. These evaluators believe that noth- ing short of rigorous experimental design methodologies such as those ~sed a labora- FUTURE DIREC'TIONS OF THE ALCOHOL-CRASH PROBLEIM tory setting will provide scientifically acceptable evidence of the success or failure of a program. Inevitably, this requires the use of a "control" group which matches the "treat- ment" group in every significant respect except exposure to the countermeasure. Critics of the use of control groups for evaluating social experiments argue that it is virtually impossible to define a control group that matches the treatment group so completely. They favor so-called "quasi-experimental designs," such as time series analysis. that examine the fluctuations of crash rates and other pertinent variables over suit;tbly long periods of time both before and after the introduction of the alcohol-safety program. A more recent school of thought rejects both the rigorously experimental and quasi- experimental approaches as impractical and unrealistic. Experimental research as a method for evaluating complex societal programs is viewed as largely irrelevent to real world needs, often leading to unwarranted rejections of programs whose effects cannot be proved statistically "significant." What is needed, it is claimed, is a way of organiz- ing and presenting information that will best support the practical needs of decision- makers (Edwards, Guttentag. and Snapper 1975). The science of decision theory is offered as a means for achieving this end. Thus, though evaluation is essential to improving programmatic responses to the alcohul-crash problem. no one knows for sure how it should be conducted. In the neara-term future. careful application of time-series analysis techniques seems the most practicable approach. At the same time, program designers and managers should be aware that the art of evaluation is still developing. Evaluation methodology "cults" that claim to provide sure-fire answers that exclude other approaches, and that defy com- mon sense, should be avoided. Research and testing of innovative approaches (includ- ing decision theoretic approaches) should be strongly supported. Finally. it is critical that the results of evaluations be carefully and thoughtfully analyzed before deciding on the worth of alcohol-safety programs. Past experience indicates that progress in dealing with the alcohol-crash problem will not come easily and that even relatively large expenditures of resources will often fail to produce an effect that can uneq~~ivocally attributed to the programs. In many cases. effects that seem to be the result of a particular program hill be disappointingly small and appear to be unworthy of the effort. Before rejecting such a program as "ineffective," one's original expectations should he critically reexamined to see if they were compatible with the enormous complexit), c3f the problem and with the limited knowledge and technol- ogy available to deal with that prc~blem. 6.3 SUMMARY AND CONCLUSIONS Analysis of likely trends in the factors believed to be most strongly related to the alcohol-crash problem indicates that the absolute magnitude of the problem will in- crease substantially over the next decade. However, alcohol-related crash losses as a fraction of total crash losses will remain about the same. A number of very basic obstacles will have to be surmounted to achieve any impor- tant reduction in these projected losses. First, the spectrum of possible targets of ALCOHOL AND HICIiWAY SAFETY I978 future programs must be widened to include population groups, factors, and events not previously considered in any detail. A comprehensive methodology is needed for systematically generating and screening new targets and possible and appropriate countermeasures. Second, approaches used in the past in alcohol safety programs will have to undergo fundamental changes, and new programs aimed at better defined targets will have to be developed. Specifically, further research is required to adequately define the parameters of deterrence. It is essential that one know what levels of detection and apprehension and what punishments are required to achieve given decreases in drunk driving. Of equal importance is the need to develop effective treatments for problem drinkers and to make better use of techniques developed in ASAP for using the Traffic Law System for case-finding, diagnosis, and referral. It is also important to utilize more effectively the available public information and education techniques for behavior modification, particularly in support of programs of general deterrence. A number of innovative ways of applying modern technology to the alcohol-crash problem have been conceptualized and, in some instances, actually developed and tested under operational conditions. Such devices as the Drunk Driver Warning System offer hope for the future and should be further refined, both with respect to the technol- ogy involved and with respect to the application of that technology in the various societal systems that interact with drinking drivers. Likewise, more widespread use should be made of the methodologies of the systems approach than has been made in the past in applying complex technologies to accomplish simple objectives (e.g., rapid air transport). Particularly, the systems approach should be applied to the design as well as to the management of alcohol safety programs. Finally, no progress or improvement can be sustained and diffused to other users without adequate evaluation. A systematic effort must be made to fill in the knowledge gaps in the alcohol-safety countermeasure programs sketched out above, a~~d will require a carefully designed, and rigorously implemented evaluation component. Failure to evaluate future programs will result in another decade of unanswered questions and lost opportunities. 7.0 CONCLUSIONS AND RECOMMENDATIONS This section summarizes the major conclusions and recommendations of the study. It lists the most significant findings on the present state of knowledge about: the nature and extent of the alcohol-crash problem in the United States and past responses to that problem. Recommendations relative to developing more effective future responses to the alcohol- crash problem are also stated. The section closes with some insights by the authors on the implications of the study's findings for operational agencies. 7.1 THE ALCOHOL-CRASH PROBLEM Research clearly shows that a significant alcohol-crash problem still exists in the United States. With respect to the nature and extent of that problem, it is concluded that: Nearly one-half of all fatally injured drivers in the United States were legally too intoxicated to drive (i.e., had a BAC of. 10% wlv, or more). @ Many drivers involved in less serious crashes (perhaps 5%-13%) were also legally too intoxicated to drive. More than one-third ~lf fatally injured pedestrians had BACs of ,1094 w/v or more. The number of alcohol-related crashes that are calrsed by alcohol is not known (as is the case with many other crash factors), but research indicates that: a. The risk of being involved in a serious crash is much greater at BACs over .lo% wlv than it is with no alcohol. b. Many basic behaviors related to driving are impaired in most indi- viduals at BACs of. 10% wlv or more. Driver and driving characteristics associated with a higher than average in,~ohpe- men? in alcohol-related serious crashes are: a. Male sex, b. Age of 20 to 60 years. c. Heavy drinking and sevc1.c drinking problems, d. Preference for beer over other alcoholic beverages, e. Nighttime driving habits. f. Weekend driving habits, and g. History of prior arrests for drunk driving. Driver characteristics associated with a higher than average crash risk after drink- ing a given amount are: a. Female sex. b. Youth (i.e., under 20 years old), c. Old age (i.e., over 60 years old), and d. Light drinking habits. Knowledge of driver characteristics and driving habits is useful for identifying high-risk groups. but is not sufficient to establish that any one individual with these characteristics or habits caused or will cause a crash. A wide range of research is reqiiired to improve the state of knowledge about the alcohol-crash problem. In the area of problem identification and definition, both epide- miologic and experimental studies are indicated. Critical c~pidomiologic research needs are : A nationwide controlled study to determine the alcohol-crash risk faced by vari- ous population groups at various BACs. Controlled studies of a more limited geographical scope to determine the crash risk of more sharply defined population groups, particularly groups defined by various drinking va~*iables. is critical that more be known about the alcohol- crash risk of certain groups (e.g., alcoholics) that are thought to have a high alcohol-crash in~.oll,cmcnt. In-depth clinical studies to learn more about the circumstances surro~nding hol-related crashes and the interactions of alcohol with other factors to cause crashes. E.upc~ritnrnftr1 research needs of an equally high priority are: Studies to identify relationships between elementary behaviors that can be tested in a laboratory and critical driving tasks. A coordinated experimental program on the effects of alcohol on these behavif rs. A wide spectrum of populations should be investigated in this program, ulth particular attention to groups indicated by past research to have either a h~gh alcohol-crash risk or a high alcohol-crash involvement (e.g., males, people with severe drinking problems). More realistic experiments on alcohol effects on actual driving performance. 7.2 RESPONSES TO THE ALCOHOL-CRASH PROBLEM Research and operational experience in dealing with the alcohol-crash problem indi- cate that: CONCLI'SIONS AND RECOMMENDATIONS Five approaches have most commonly been followed to control alcohol-crash losses: a. Legal. b. Health, c. Public Information and Education. d. Technological. and e. Systems. The targets of programs that have followed these approaches have usually been defined only in general terms. e.g.. all drunk drivers. social drinker-drivers, prob- lem drinker-drivers. To date only one large-scale alcohol-safety program, the British Road Safety Act of 1967, has clearly been shown to have reduced crash losses involving drinking drivers and the effects of that program were transitory. The state of knowledge about fundamental hypotheses upon which most past alcohol-safety programs have been based is totally inadequate for designing and operating effective programs, Specifically. it is not known: a. What kind and what amount of a deterrent threat is required to achieve what level of results in a specific application of the legul approach. b. What treatments are required for what classes of drivers to achieve what level of results in a specific application of the Itc~nltll approach. This lack of knowledge is not unique to the field of alcohol-safety. Efforts to apply the legal and health approaches to controlling other forms of individual and societal risk (e.g., crime, drug dependence) are also hampered by similar informa- tional deficiencies. With regard to future responses to the alcohol-crash problem. it is believed that: The absolute magnitude of the problem will increase substantially in the 1975- 1985 period, but that alcohol-related crashes as a fraction of total crashes will remain about the same. 0 A wider spectrum of targets of future alcohol-safety programs must be developed to address more relevant and responsive population groups, factors, and events. Present alcohol-safet;, plugrams should be evaluated to provide a knowledge-base for designing new programs. Future alcohol-safety programs should be carefully tested and evaluated before being placed into full-scale operation. In order to develop more effective programs for dealing with the alcohol-crash prob- lem of the future, the following research is indicated: A comprehensive analysis of targets of possible alcohol-safety programs. Studies to identify deterrent threats and treatment and rehabilitation regimens most appropriate to drinking drivers. Studies to better understand the principal elements of public information and education relative to modifying drinking-driving behavior. ALCOHOL AND HIGHWAY SAFETY 1978 Efforts to develop and refine technologies that could be used to support legal, health, and other approaches to controlling alcohol-crash losses. Barriers (e.g., legal, political, economic) to operationalizing such approaches should be tho- roughly analyzed. Research on how best to apply the systems approach to the design of alcohol- safety programs as well as to the management and evaluation of such programs. Studies to develop more appropriate techniques and methodologies for evaluating alcohol-safety programs and for applying the results of such evaluations to the design and operation of new programs. It has often been said that the most predictable outcome of a research study is the recommendation for more research. This result was inevitable in the present study because an explicit objective of our contract was to recommend "future research activi- ties that are considered likely to produce the most significant results" in reducing alcohol-crash losses. It was also hoped that an objective review of existing information on alcohol and highway safety would identify approaches that were effective in reducing the risk of crashes that could be recommended to state and local operational agencies. Regrettably, this cannot be done. There are no approaches whose efficacy has been objectively established. In part, this may be attributed to the general lack of evaluation of the effect of efforts to reduce alcohol-related crash losses. The lack of information on effectiveness can also be attributed to a general tendency at all levels of government to implement programs to deal with drinking and driving on the assumption that the par- ticular strategies chosen will work. The selection of strategies in the past has not been based on the findings of a carefully designed research and development program. This suggests that two important lessons should be drawn from the existing literature: The present efforts of state and local jurisdictions to deal with the drinking driver should be carefully evaluated. New efforts or strategies should not be implemented by state and local jurisdic- tions until an adequate foundation has been established through an objective research and development process. 7.3 INSIGHTS FOR OPERATIONAL AGENCIES It is recognized that state and local jurisdictions are faced with the immediate prob- lem of managing the risk created by the drinking driver. Decisions are being made ai:l must be made on the basis of current knowledge. Better information is certainly needed for the future, but actions must be taken now. Thus, we offer some suggestions for the present. In view of the lack of objective evidence to support recommendations, these suggestions must be understood to represent judgments of the authors flowing from the synthesis of the existing literature and our experience. They were not derived directly from objective evidence as were the prior conclusions and recommendations, but repre- sent our insights and are offered only in that context. The risk of traffic crashes from the use of alcohol in our society is a complex social phenomenon. The approaches that have been developed to manage that risk are equally CONCLUSIONS AND RECOMMENDATIONS - complex. Given the unique characteristics of many local situations, no single prescrip- tive approach can be recommended. We believe, however, that each jurisdiction should approach the problem in a systematic manner. We believe that a program to manage the risk of the drinking driver should address the following areas: Risk Identijicmtion-Information on the nature and extent of the alcohol-related crash problem within the jurisdiction should be established. This information should be made available to the public and the individuals, agencies, and institu- tions responsible for dealing with the alcohol and highway crash problem. Priorities for Resource Alloc~ation-The alcohol-related crash problem should be compared with other public safety and public health problems faced at the state and community level. Conscious decisions to allocate existing and future re- sources to the alcohol-crash problem commensurate with its relative magnitude should be made. Selection of Control Str~tegi~s-A formal method for identifying control strate- gies and selecting those most appropriate for the local situation should be estab- lished. This suggests a "systems approach" and deliberate local coordination of the involved agencies and institutions. As noted previously, specific strategies or tactics cannot be recommended on the basis of established effectiveness. Certain approaches, however, are suggested as representing the most promising now known. These include: Special Deterrent Approaches-These approaches are focused on an individ- ual who has been identified as a drinking driver. This usually occurs through law enforcement action. The use of the legal system to detect and sanction drinking drivers appears justified. The available sanctions should be sufficiently broad to deal effectively with the needs of individual cases. In particular, individuals who are clearly identified as having severe drinking problems should be referred to the health care system. (This has been de- scribed as the "healthilegal" approach.) General Deterrent Approaches-These approaches are designed to reduce the incidence of drinking-driving and are broadly targeted. For example, public information and education efforts to convey information about the risk of a crash after drinking, the risk of law enforcement action, and the prob- able sanctions-both direct and indirect (e.g., insurance costs)--st 3uld be undertaken to complement law system actions. Control System Management-Implementation of the "systems approach" sug- gested earlier requires coordination of the various elements of the drinking driver control system. In most jurisdictions many different agencies of government from the executive, legislative and judicial branches and are involved in the manage- ment of the risk of alcohol-related crashes. While appointment of an individual to "manage" this loosely knit system is not feasible, structures can be created that enhance communication and improve operating efficiency. Evaluation-The clear need for objective evaluation of present and future efforts has been stressed throughout this report. The lack of present knowledge is directly attributable to the lack of evaluation of past efforts. Evaluation must be accomplished to operate a local program effectively and to increase the general knowledge base. What is known about drinking driver behavior and accidents suggests strongly that an eval~ration program should include measurement of alcohol involvement in the general driving population as well as in the accident population. The elements identified above are believed to be necessary for programs intended to reduce the risk of alcohol-related crashes. The present "state of the knowledge" does not allow ucj to state with certainty that a program encompassing all these elements itqill be effective in reducing crash losses. Based on the current knowledge. however, we believe that such a program would be the best use of existing resources. As previously noted. introdi~ction of new approaches and new technologies should flow from a carefully structured research and development effort so that significant funds are not spent on large-scale implementation of unproven approaches. 8.0 REFERENCES Adams. A.J.; Brown. B.: Flom. M.C.; Jones. R.T.: and Jampolsky. A. 1975. 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DWI trrrest.~. National Highway Traffic Safety Administration. Technical Report. DOT-HS-801-151, Zador, P. 1976. Statistical evaluation of the effectiveness of "Alcohol Safety Action Projects." Ar~ident Anrrlysis ond Pre ~,c'~rrion 5 1-66. . 1977. A rejoinder to "A critique of the paper 'statistical evaluation of the effectiveness of Alcohol Safety Action Programs' by Johnson, et al." Ar.r,idcnt Anril~,si.s irtld Prc~~,et?tion 15-19. Zelhart. P.F.. Jr, and Schurr. B.C. 1975. Tlrr, Alhcrtrr imprririd dri1,or.c' progrtrnl . Finul report on e~.alrrrr- tiot~. Canada: Ministry of Transport. Zimring. F.E. and Hawkinh. G.J. 1973. L)c~tr~rrr~~rc Ir~grrl /Irrr,(tt it/ irimr~ i,onrr~ol. Chicago: Uni~ersity of Chicago hess. Zylman. R. 1968. Accidents, alcohol ;~nd s~ngle cause expl:~n~rtions: from the Grand Rapids study. Qiicirterly Jorirnirl r!/'Sttrtlic,\ on Alr,ohol. Supplement No. 4: 212-33. . 1971. Analysis of studies compi~ring collision-involved drivers and non-involved drivers. Jorirnril ctf Sr,fctp Rr.vcrrrc.lr 3: 116-28. . 1972a. Race and social st;itu\. Important factors in alcohol-related collisions. Paper presented at the 30th International Congress on Alcoholism ilnd Drug Dependence. Amsterdam. September 1972. . 1972h. Youth. alcohol. and collision involven~ent. In Proceedings of tllr Joint Conference on Alc,ol1ol Ahri.\c, c11td Alc olrolism. Rockville. Maryland: N;itional Institute on Alcohol Abuse and Alco- holism. . 1973a. Semantic gymnastics in alcohol-highway crash research and public information programs. In Proc,eeding.~ 0.1' Si.rtcrntlr Con,/ilr~t~c,r tllr Attleric,cln A.ssoc,iution fi)r .41itomotil,r Medicine. New York, N.Y.: Society of Automotive Engineers. Inc. -- . 197%. Time of day as a factor in collision-involvement of drunken drivers. Qurirrc~rly Jorrrt~cil of St11die.s on Ali~olrol 34: 527-29. . 1974. A critical evi~luation of the literature on "alcohol involvement" in highway deaths. Ai.c,idvtit Anulysi~ find Pr~l,rtition 163-204. . 1975. DWI enforcement programs: Why ase they not more effective? Acc,ident Analysis nnd Pre- 1,erlrion 7(3): 179-90. . 1976a. All alcoholics are high risk drivers: A myth. Jorrrnrrl c:f'Trnf;h'r, Sr!fi~ty 23(2): 7- 10. . 1976b. When it became legal to drink at 18 in Massachusetts and Maine, what happened? Polic~) Cllic~,f'43( 56-59. Zylman. R.; Blomberg. R.D.: and Preusser. D.F. 1975. A rrl,i~)~ litr~rrrtr~r~ tlte in~.ol~.rmenl trlc,ohol in podestrirrtl r ollisiot~ rr.si~ltini( tletrtl1 rind irljriry. National Highway Traffic Safety Admin- istration. Technical Report. DOT-HS-801-413. THE PRINCIPAL, INVESTIGATORS The principal investigators for thi5 project have worked together for the past ten years on research in the field of highway safety. Through this work, they developed a special interest in the role of alcohol and drugs in highway crashes and have analyzed and helped design methods for dealing with that problem. Their backgrounds and re- +earth interests are summarized briefly below. Ralph K. Jones, is president of Mid-America Research Institute, Inc., and a staff consultant to the Highway Safety Research Institute of The University of Michigan. He received his B.S. in mathematics from Drury College in 1950 and studied afterward at Wichita State University, The University of Michigan, and Purdue University. He is currently involved in research and research management in the areas of transportation, health, and safety. He has directed and participated substantively in a wide variety of NHTSA-sponsored research and demonstration projects dealing with the human com- ponent of the Highway Transportation System. Kent B. Joscelyn is head of the Policy Analysis Division of The University of Michi- gan Highway Safety Research Institute. He received a B.S. degree in physics from Union College in 1957 and a J.D. degree from Albany Law School in 1960. He is a member of the bar of the State of New York and the District of Columbia. Mr. Joscelyn is a member of numerous professional societies and advisory committees and is the editor of the international Journal c$ Criminal J~sticse. His research interests span a broad spectrum of subjef I nlatter areas related to the analysis of societal systems, including law, public safety, and systems analysis. In his present position he manages and participates in public policy research focused on transportation. health, and safety issues.