Most modern heavy trucks have some form of an event data recorder, although they are not "designed" to have them. Data can be obtained from various modules throughout the vehicle, that can give insight into speed, braking, and other factors prior to a "trigger", or an event that records data.

These events were designed to give manufacturers and mechanics an indication of what was going on in the truck when a "fault" or "diagnostic trouble code" occurred.

When applied properly, and with validation, this data can be used in collision investigations.

James Loftis is one of a few instructors who teach this application to police officers, engineers, and private investigators. James helped develop the curriculum for this training, and frequently does validation testing on various truck engines, and other modules capable of giving this data.