Evaluation of 2006 Wisconsin 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 Wisconsin. MCMIS Crash File records were matched to the Wisconsin Crash file to determine the nature and extent of underreporting. Overall, it appears that Wisconsin is reporting 71.0 percent of crash involvements that should be reported to the MCMIS Crash file. All of the variables needed to identify vehicles that should be reported to the MCMIS Crash file are recorded in the Wisconsin PAR file. The vehicle type variable seems to be a derived variable since there is no space for recording levels of vehicle type on the crash report form. Vehicles coded as utility trucks are not included in this evaluation because it is estimated that only 8 percent have GVWR greater than 10,000 pounds. The reporting rate for tractor combinations is close to 90 percent, but the rate for straight trucks is approximately 50 percent. Reporting rates also show a decreasing trend as crash severity decreases. The reporting rate for the towed due to disabling damage criterion is 67.6 percent. Based on agency type, the reporting rate for the state patrol is 81.5 percent. Missing data percentages in the MCMIS Crash File are generally low, except as noted for certain variables. A comparison of the vehicle configuration variable between the Wisconsin and MCMIS Crash files shows some disagreement in the coding of this variable.