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The GPS (Global Positioning System) is a navigational tool available to the public, comprising in part a network of satellites in orbit broadcasting signals to GPS receivers on earth. Due in large part to the very accurate clocks in the system, a GPS receiver that receives a number of these signals simultaneously can then establish its location on earth. Some GPS receiver models have the capability to record a history of the latitude and longitude co-ordinates at known times, and these may later be downloaded and viewed on a computer using applicable software. Effectively, this provides the equivalent of a bread crumb trail of the path taken by the receiver, although the frequency of the data points can vary substantially from one model to another, and it may not be adjustable by the user. By plotting the information on a map, the trail can be viewed and the position-time history of the vehicle may become evident.

The distance, velocity and acceleration characteristics versus time of heavy trucks for use in accident reconstruction have been the subject of studies by Grimes and others. To date, the majority of the research has been done using tractor-semitrailers equipped with standard transmissions. In recent years, as transmission technology has improved, automated and automatic transmissions are becoming popular on North American roadways. A series of tests were performed to document the acceleration characteristics of two different tractors, a 2007 Volvo VNL and a 2011 Freightliner Cascadia, both equipped with automated transmissions towing both empty and loaded semitrailers. The vehicles were instrumented with a Racelogic™ VBOX III GPS data-logging device that measured speed. Other vehicle parameters were logged using the recording software manufactured for the specific engine manufacturer.