This study examined the relationship between a driver's driving record while operating a private vehicle and his record while driving a commercial truck. Approximately 240,000 drivers licensed to operate tractor trailers, from the states of North Carolina and Washington, constituted the study populations. Data were collected from state driver history, citation, and crash files, and motor carrier files for the periods 1981-1982 and 1983-1984. A number of driver record variables from the first time period were found to be associated with crash involvement of drivers in commercial vehicles in the second time period.