A: Collisions are analyzed for a wide range of reasons:
- Law enforcement has a need to determine speeds of vehicles in order to ascertain the circumstances of a collision; Who is to blame for the collision? Were any laws broken? Was the accident avoidable? They are mainly looking for the speeds, not the impact speed change.
Insurance and litigation driven investigations all have a need to determine speeds of vehicles in order to ascertain the circumstances of a collision to find out who’s responsible for damages? There is a need for speed AND impact speed change to determine responsibility AND to determine whether the injury or death from the accident ‘would be expected’ or is unique. Part of the determination of ‘what levels of deltaV do people die or get seriously injured’ comes from the statistical studies performed by the 3rd group of people who analyze collisions:
Federal, state and private researchers (NHTSA, AASHTO, etc.) all have a need to get a basic overview of the circumstances surrounding groups of accidents in order to determine where and how occupants of vehicles are getting killed and injured. Is it due to driver behavior? Vehicle design? Roadway design? Or some combination of each? Here the DeltaV plays an important role in determining trends. This helps determine possible safety measures to propose to help reduce fatalities and injuries.
- For individual collision, there is a requirement for more accuracy and so more sophisticated techniques are required and a more in-depth investigation performed.
For additional information see Accident Reconstruction Techniques and Accuracy
For a history of NHTSA NASS studies, see Review of CRASH Damage Analysis
For a presentation of more sophisticated techniques, see SMAC Computer Program