Evaluation of 2007 Arkansas crash data reported to the MCMIS crash file

Abstract

This report is part of a series evaluating the data reported to the Motor Carrier Management Information System (MCMIS) Crash File undertaken by the Center for National Truck and Bus Statistics at the University of Michigan Transportation Research Institute. The earlier studies showed that reporting to the MCMIS Crash File was incomplete. This report examines the factors that are associated with reporting rates for the state of Arkansas. MCMIS Crash File records were matched to the Arkansas Crash file to determine the reporting rate and factors that affect the reporting rate. Only crashes with K, A, or B injuries could be evaluated directly for completeness of reporting. Within this group, 72.5 percent of reportable cases were reported. Two independent means were developed to estimate the overall reporting rate. These resulted in estimated overall reporting rates from 48 percent to 68 percent. Reporting rates were related to crash severity, with fatal involvements most likely to be reported, than less serious crash involvements. The involvements of large trucks were more likely to be reported than those of smaller trucks or buses. Reporting rates also varied by the type of investigation agency (state police, county sheriff, or city police). Missing data rates are low for most variables. Data on hazardous materials in the crash is only available from the supplemental form, and missing data is high for the hazmat materials name and the 4-digit hazmat class.