The traditional method used by law enforcement agencies to measure the scenes of traffic accidents is the coordinate method, which involves establishing a base line and measuring perpendicular-offset distances to points of interest. The measurements are usually taken with a 100-foot tape, or a distance-measuring wheel. In many cases, use of the coordinate method requires that traffic lanes be closed for an hour or more in order to allow the investigating officers to make the measurements needed to adequately document the accident scene. The lane closures often increase traffic delay and the risk of secondary collisions. Diagrams of the accident scenes are prepared manually from the measurements.

In recent years, some law enforcement agencies have started using total station surveying equipment to document traffic accident scenes. This system features an electronic theodolite equipped with an internal electronic distance-measuring device and a builtin microprocessor, which make it possible to automatically measure and record distances and angles to a reflector placed at the points of interest at the accident scene. The survey data are recorded in an electronic file, which is processed in the office to generate an accurate, scale diagram of the accident scene. Experience with the total station surveying system indicates that about twice as many measurements can be taken in half the time required with the conventional coordinate method. Also, it reduces the number and duration of lane closures required to measure the accident scene, which in turn reduces the delay to traffic, the potential of secondary accidents, and the risk to the investigating officers.