In order to assess large truck safety, information is needed on vchicle exposure to accidents (travel) as well as on involvement in accidents. Since 1979, the University of Michigan Transportation Research Institute has collected detailed data on every fatal large truck accident in the U.S., about 5,000 cases a year. With the completion of the first comprehensivel arge truck exposure data survey, by UMTRI, we will be able to go beyond past analyses of large truck accidents. The National Truck Trip Information Survey (NTTIS) was initiated in late 1985. Data collection was completed in February 1987. For this survey the owners of over 4,000 large trucks were contacted four times over a twelve-month period (16,000 survey days) to obtain detailed information on the use of the truck on a randomly-selected survey date. The information collected includes the configuration, catgo, actual weight, and the route the truck followed. The combination of accident data with miles traveled from NTTIS will enable the calculation of fatal accident involvement rates by vehicle type, road class, etc.