The reconstruction of an accident involves determining the movement of vehicles in the the few seconds leading up to the accident, the movement of the vehicle during the collision and the subsequent movement of the vehicle.
In the case of large goods vehicles, this information is recorded on the tachograph chart. The tachograph is an instrument which records time, speed, travel distance and driver work mode. Its main purpose is to enable checks to be made on the hours driven, rest periods taken and distance driven. However, when the chart is examined under a microscope, much useful accident information can be obtained. Vehicles are now commonly furnished with digital tachographs which can provide more extensive data about vehicle movments.