by U. S. Department of Transportation (Author)

Each crash must have at least one in-transport motor vehicle involved. The value entered must equal the total number of in-transport motor vehicles involved in the crash. Vehicles not in- transport are not included in this variable's count. In order for a vehicle to be considered in-transport, the motor vehicle must be either (1) on the roadway or (2) in motion. This includes driverless vehicles.