Assessment of the effectiveness of proposed “Keep Right Pass Left – It’s the Law” signs on two lane rural freeways

Show simple item record Dion, F. en_US
dc.contributor Liang, Z. en_US 2008-01-22T16:45:27Z 2008-01-22T16:45:27Z 2007-12
dc.identifier 100609 en_US
dc.identifier.other UMTRI-2007-45 en_US
dc.description.abstract This study focuses on the problem of unlawful left-lane usage on non-congested two-lane rural freeways in Michigan. According to the Michigan Vehicle Code, vehicles shall remain on the right lane of two-lane sections of rural freeways when not passing other vehicles. While drivers are currently reminded of this rule by signs stating “Slower Traffic Keep Right” installed as part of the normal post-interchange sign sequence, traffic observations suggest that many motorists do not to follow this rule. As part of an effort to entice drivers to abide by existing rules, this study investigates a proposal to replace current “Slower Traffic Keep Right” signs with new explicit signs stating “Keep Right Pass Left – It’s the Law”. To assess the effectiveness of this replacement, traffic behavioral data were collected at four rural sites along I-96 in Michigan, first with the existing sign in place and then with the proposed new sign. Tube counters data were collected to compare lane-specific traffic volumes and speed distributions in the presence of each sign. Video data were further collected to obtain information about individual passing events and develop statistics about the validity of left-lane usage by individual vehicles and about left-lane vehicle groupings caused by slow moving vehicles in the freeway left lane. Results of the analyses provide no indication that replacing existing “Slower Traffic Keep Right” sings would effectively improve left-lane usage behavior on two-lane rural freeways. Depending on the sites considered, either improvements or deteriorations in left-lane behavior were observed following the sign replacement. In all cases, statistical tests further indicate that the observed changes are not statistically significant. en_US
dc.description.sponsorship Michigan Department of Transportation, Lansing, MI en_US
dc.format.extent 43 en_US
dc.format.extent 951545 bytes
dc.format.mimetype application/pdf
dc.language English en_US
dc.publisher University of Michigan, Ann Arbor, Transportation Research Institute en_US
dc.subject.other Signs/ Signals en_US
dc.subject.other Limited-Access Highways/ Controlled-Access Highways en_US
dc.subject.other Traffic Flow en_US
dc.subject.other Passing/ Overtaking en_US
dc.subject.other Motor Vehicle Codes en_US
dc.subject.other Traffic Control Devices en_US
dc.subject.other Lanes en_US
dc.subject.other Data Analysis en_US
dc.title Assessment of the effectiveness of proposed “Keep Right Pass Left – It’s the Law” signs on two lane rural freeways en_US
dc.type Technical Report en_US
dc.subject.hlbsecondlevel Transportation
dc.subject.hlbtoplevel Engineering
dc.description.bitstreamurl en_US
dc.owningcollname Transportation Research Institute (UMTRI)
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