Trucking accidents expert witnesses may write reports and testify on crashworthiness, truck maintenance, hours of service, and associated matters. In The Large Truck Crash Causation Study, the Federal Motor Carrier Safety Administration Office of Research and Analysis reports:
Coding Crash Causation Variables
Many variables were coded from the hundreds of data elements collected on each crash. Three key variables were coded for assessing crash risk:
* Critical Event: The action or event that put the vehicle or vehicles on a course that made the collision unavoidable. The critical event is assigned to the vehicle that took the action that made the crash inevitable.
* Critical Reason: The immediate reason for the critical event (i.e., the failure leading to the critical event). The critical reason is assigned to the vehicle coded with the critical event in the crash. It can be coded as a driver error, vehicle failure, or environmental condition (roadway or weather).
* Associated Factors: The person, vehicle, and environmental conditions present at the time of the crash. No judgment is made as to whether any factor is related to the reason for a particular crash, just whether the factor was present. The list of the many factors that can be coded provides enough information to describe the circumstances of the crash.