This Vehicle Accident Investigation Reference manual is intended for use at road traffic accident sites, and is designed in conjunction with the Vehicle Accident Investigation Checklist to provide guidance for the gathering of physical evidence at accident sites by personnel providing the initial response to an accident. The information that can be collected from live accident scenes, or recent accident sites, can be crucial in allowing investigators to accurately reconstruct an incident. This “physical evidence” is much more reliable than witness statements in allowing the incident to be reconstructed.