Evaluation of 2005 Arizona 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. Earlier studies showed that reporting to the MCMIS Crash File was incomplete. This report examines factors that are associated with reporting rates for the state of Arizona. MCMIS Crash File records were matched to the Arizona Crash file to determine the nature and extent of underreporting. Overall, it appears that Arizona is reporting 78.2 percent of crash involvements that should be reported to the MCMIS Crash file. Based on crash severity, the reporting rate is 93.8 percent for fatal crashes, 83.4 percent for injured/transported crashes, and 75.6 percent for towed/disabled crashes. It is possible that the number of injured/transported reportable cases is underestimated since the definition was applied in the strict sense using the medical transport variable. The reporting rate for trucks is 77.8 percent, and the rate for buses is 82.5 percent. The reporting rates for the Arizona Highway Patrol, sheriffs offices, and police departments are 82.4 percent, 79.6 percent, and 74.0 percent, respectively. It appears that 66 of the 4,411 reportable cases involved explosion or fire and only 2 of these were not reported. Of the 66 vehicles, 44 involved no injury. Missing data rates are generally low for most variables in the MCMIS Crash file, except in a few instances as noted.