Media accounts of motor vehicle accidents in Seattle and the surrounding area frequently end with the statement “The investigation of the accident is continuing.” This statement may seem to be self-contradictory if the involved vehicles have been removed from the accident site and if debris has been cleaned up. What can be left to investigate?
The answer is “Lots.” The accident itself will leave many clues to the sequence of events that led to the collision. Evidence such as tire marks, damage to each of the vehicles, damage to signs, fences and other roadside structures and occasionally the nature of injuries suffered by occupants of the vehicles provide trained investigators with abundant evidence that can be studied and analyzed to determine the cause of the accident. These investigators, known mostly as forensic engineers, use scientific principles from mathematics, physics, chemistry, and other disciplines to reconstruct the events comprising the accident.
First steps
The investigator’s first steps require an extensive inspection of the accident site. The investigators begin by carefully noting the location of each vehicle and the location of debris from the accident. Skid marks are noted by size and location. Debris from the vehicles, such as fenders, license plates, and glass fragments are marked with symbols that help investigators determine where the piece was found.
An essential part of each investigation is the making of a photographic record of the scene as soon as possible after the accident. This record is often made using modern digital photographic equipment and techniques. Another valuable source of evidence is witness statements, both from bystanders and victims who were in the vehicles.
All of this evidence is taken by the investigator to a research facility where the vehicles can be disassembled and inspected for clues to the accident. Most forensic engineers maintain a large library of information concerning the resistance to force of automobile frames, skid resistance, and similar information. These sources can be consulted to provide a useful comparison with the crash damage suffered by the involved vehicles.
Video simulation
Perhaps the most remarkable output of this investigation is a computer simulation of the accident itself. Depending upon the software employed by the engineers, the accident can be made to repeat itself on computer screens for study by the lawyers, the judge, the jury, and other experts.
These simulations are often employed if the accident results in a court trial. A digital reconstruction of the accident that demonstrates the path of each vehicle can be very persuasive evidence that can go a long way toward establishing liability.