Evaluation of 2005 Nebraska 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 Nebraska. MCMIS Crash File records were matched to the Nebraska Crash file to determine the nature and extent of underreporting. Overall, it appears that Nebraska is reporting 86.8 percent of crash involvements that should be reported to the MCMIS Crash file. However, since Nebraska overwrites the vehicle type information on the main crash report with the configuration information from the truck/bus supplement, it is not possible to verify that all trucks and buses have been identified. Reporting rates were linearly related to crash severity, with fatal involvements most likely to be reported, and tow/disabled crashes least likely. Reporting rates also varied by the type of investigation agency (state police, county, or city police). Missing data rates are low for most variables, although were 100 percent for driver license class and GVWR class. It appears that the GVWR information is available but just not uploaded. Some inconsistencies between data reported to the MCMIS file and recorded in the Nebraska data were also noted.