GPS Analysis

Advances in technology are providing increasingly valuable information for investigators to use when analysing motor vehicle collisions.  Today, many passenger vehicles are equipped with factory and after-market GPS receivers.  These receivers can record important data such as time, location, heading and speed.  This information is also available in many fleet vehicles, such as tractor-trailers and taxis, as well as emergency vehicles (police, fire and ambulances).


The accuracy of this information varies between different GPS receivers.  Testing by BME (“Accuracy of GPS Speed and Location Data Measured in Emergency Vehicles”) has revealed that many GPS receivers calculate speed with very small errors – less than 0.5 km/h!  All GPS receivers are unique, however, with their own idiosyncrasies.

When conducting a collision investigation, it is important to not only be aware that this information exists so that it can be preserved, but also to be aware of the accuracy and limitations of this data.


David M. Little P.Eng.