The National Highway Traffic Safety Administration
The National Highway Traffic Safety Administration funded the first national guidelines for the standardization training in the field of traffic accident reconstruction in 1985. This led to the establishment of Accreditation Commission for Traffic Accident Reconstruction (ACTAR), an industry accreditation group. The development meticulous accident reconstructions of motorcycle accidents helped to explain that proper helmets reduced head injuries, most motorcyclists needed more driver training to control skids, and a large percertage of motorcycle accidents involved left-turning automobiles turning in front of the oncoming motorcycle
Scene inspections and data recovery involves visiting the scene of the accident and investigating all of the vehicles involved in the collision. Investigations involve collecting evidence such as scene photographs, video of the collision, measurements of the scene, eyewitness testimony, and legal depositions. Additional factors include steering angles, braking, use of lights, turn signals, speed, acceleration, engine rpm, cruise control, and anti-lock brakes. Witnesses are interviewed during accident reconstruction, and physical evidence such as tire marks are examined. The length of a skid mark can often allow calculation of the original speed of a vehicle for example. Vehicle speeds are frequently under-estimated by a driver, so an independent estimate of speed is often essential in accidents. Inspection of the road surface is also vital.
Vehicular accident reconstruction analysis includes processing data collecting, evaluating possible hypotheses, creating models, recreating accidents, testing, and utilizing software simulations. Like many other technical activities, accident reconstruction has been revolutionized by the use of powerful, inexpensive computers and specialty software. Various types of accident reconstruction software are used to recreate crash and crime scenes and to perform other useful tasks involved in reconstructing collisions. Accident reconstruction software is regularly used by law enforcement personnel and consultants to analyze a collision and to demonstrate what occurred in an accident. Examples of types of software used by accident reconstructionists are CAD (computer aided design) programs, vehicle specification databases, momentum and energy analysis programs, collision simulators, and photogrammetry software.
After the analysis is completed, forensic engineers compile report findings, diagrams, and animations to form their expert testimony and conclusions relating to the accident. Forensic animation typically depicts all or part of an accident sequence in a video format so that non-technical parties, such as juries, can easily understand the expert's opinions regarding that event. To be physically realistic, an animation needs to be created by someone with a knowledge of physics, dynamics and engineering. When animations are used in a courtroom setting, they should be carefully scrutinized. Animation software can be easily misused, because motions which are not physically possible can be displayed. A reliable animation must be based on physical evidence and calculations which embody the laws of physics, and the animation should only be used to demonstrate in a visual fashion the underlying calculations made by the expert analyzing the case.
Motorcycle Accident Reconstruction
Motorcycle accident reconstruction is similar to other accident reconstruction techniques and relies on the same basic principles of conservation of energy and momentum as automobile accident reconstruction plus adds the specifics of motorcycle dynamics and rider control. Proper reconstruction of a motorcycle accident requires detailed knowledge of motorcycle dynamics plus knowledge of how motorcycles react to rider input. Motorcycle accident reconstruction follows reverse a chronological order of events, working from the point of rest of the motorcycle and/or rider backwards to a point in time before to the start of the accident sequence to when possible actions could have prevented the crash. Motorycle accident reconstruction relies on knowledge of the 5 phases of a motorcycle accident.