Evaluation of 2008 Mississippi 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 Mississippi. MCMIS Crash File records were matched to the Mississippi crash file to determine the nature and extent of underreporting. Overall, it appears that for 2008 Mississippi reported 38.0 percent of crash involvements that qualified for reporting to the MCMIS Crash file. About 3.0 percent of the reported cases did not meet the reporting criteria. Reporting rates were found to be related primarily to crash severity, the type of enforcement agency that covered the crash, and whether the reporting officer completed the Commercial Vehicle section of the Uniform Crash Report. Over 84 percent of fatal crashes were reported, compared with 36.4 percent of injury/transported crashes, and 35.8 percent of tow/disabled involvements. Reporting did not seem to vary significantly by truck size, but only 25 percent of “commercial” buses were reported, and less than 3 percent of school buses. Crashes covered by the State High Patrol were reported at the highest rate, though that was only 49.6 percent. Missing data rates are low for most variables. Overall, the crash report is designed to support full reporting. Most of the information necessary to identify reportable cases is available in the crash file, so a substantial improvement in the reporting rate can be achieved.