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Vehicle post-impact travel distances are often available to the accident reconstructionist. Energy dissipated after impact can be significant, and it is often necessary to account for this energy. The deceleration and energy dissipation experienced by a vehicle after a collision is dependent on many variables including tire rolling resistance, engine and drive-train resistance and aerodynamic drag. New technologies that significantly modify the traditional drive train, low rolling resistance tires, and new aerodynamic body designs affect vehicle deceleration, but associated data is not widely available. Roll-out tests were performed in which speed, acceleration and position measurements were made. Vehicles tested were equipped with hybrid (gasoline-electric) and standard engines, CVT (continuously variable transmission), manual and automatic transmissions, and two wheel and four-wheel drive.

Previous studies into wheel or tire disablements have examined either the physical effects of loose lug nuts, or vehicle dynamics following a disablement. This study investigates driver perception of loose lug nuts on the left rear wheel of a sedan. Testing was conducted in which a 2002 Mercury Grand Marquis was driven at various speeds through a course which included several turns, with the lug nuts tight and loose. The vehicle was instrumented to record steering wheel acceleration, steering wheel angle, and seat cushion acceleration. The driver was videotaped from the vehicle interior and the vehicle and wheel motion was videotaped from the vehicle exterior. In the test with loose lug nuts the left rear wheel separated from the vehicle. The driver's subjective observations indicated that the condition of the loose left rear wheel was not perceivable prior to wheel loss. Physical evidence on the vehicle components and roadway is described.