Seat Belts & Air Bags
Occupant restrint systems such as seat belt and air bags are critical components for occupant protection and safety during a motor vehicle collision. They provide several useful and necessary functions, including:
Ridedown - extending (or softening) the impact and delta-v (change in velocity) over a greater time and/or distance for the benefit of occupants; thereby decreasing acceleration (or deceleration) and forces applied to the occupant's body.
Prevention of Partial or Full Ejection from the Vehicle
Distribution of Forces over a Larger Area & to the Stronger Anatomy of the Body
Prevention of Contact with the Vehicle Interior (E.G., steering wheel, windshield, instrument panel, doors) or other occupants
In many automobile crash cases, there are questions whether the seat belts or air bag systems performed properly or according to design criteria. In other accidents, there may be an issue raised as to whether a particular driver or passenger was wearing their seat belt.
A preserved accident vehicle may contain an abundance of visible physical evidence that helps to analyze a variety of restraint system issues regarding use, nonuse, or performance. In addition, vehicles equipped with an EDR (Event Date Recorder) may have CDR (Crash Data Retrieval) capabilities that aslo provide information regarding restraint system use and performance.