Evaluation of 2007 Minnesota 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 Minnesota. MCMIS Crash File records were matched to the Minnesota Crash file to determine the nature and extent of underreporting. Overall, it appears that Minnesota is reporting 79.9 percent of crash involvements that should be reported to the MCMIS Crash file. Reportable cases could be identified in the Minnesota data reasonably well using the coded data, with some qualification for the towed/disabled crash severity. Reporting rates were related to crash severity, with fatal or injury/transported involvements most likely to be reported, and tow/disabled crashes less likely. Reporting rates also varied by the type of vehicle, with small buses (8-15 passenger) less likely to be reported than trucks or large buses; by state of registration, with in-state vehicles less likely to be reported than out-of-state; and by the type of investigation agency (state police, county, or city police). Missing data rates are low for most variables reported to the crash file. Some inconsistencies between data reported to the MCMIS file and recorded in the Minnesota data were also noted.