Trucks Transporting Hazardous Materials

fmcsa.dot.gov, Oct 13, 2005

The primary crash data source for this brief is the Trucks Involved in Fatal Accidents TIFA file, compiled by the Center for National Truck Statistics at the University of Michigan Transportation Research Institute UMTRI. The TIFA file is based on the National Highway Traffic Safety Administration's NHTSA Fatality Analysis Reporting System FARS file. TIFA supplements FARS by providing a careful identification of all large trucks involved in fatal crashes, along with a detailed description of the physical configuration of the truck, including weight and length, cargo body style, cargo, and cargo spillage.

Two sources provided additional data on nonfatal crashes for this brief: the National Automotive Sampling System's General Estimates System GES file, produced by NHTSA, and the Motor Carrier Management Information System MCMIS Crash File, produced by the Federal Motor Carrier Safety Administration FMCSA. The GES file is a nationally representative sample of all police-reported crashes. The MCMIS Crash File contains State-reported data on all trucks defined as a cargo-carrying vehicle with at least two axles and six tires on the ground involved in a crash that resulted in a fatality, injury, or at least one vehicle towed from the crash scene due to disabling damage sustained in the crash.

While both GES and the MCMIS Crash File have data on fatal crashes, TIFA is a more reliable source for fatal data. GES and the MCMIS Crash File will be used here for data on nonfatal crashes. A major difference between these two files in the nonfatal area is that GES includes data on all property-damage-only PDO crashes, while MCMIS contains data on only those PDO crashes that involve a towaway-a small percentage of all PDO crashes.