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This study presents a method to characterize the accuracy and precision of video-acceleration-position (VAP) devices, and presents results from testing of one such vehicle camera (“dashcam”) with global positioning system (GPS) used by taxi companies nationwide. Tests were performed in which vehicle kinematic data were recorded in a variety of real world conditions simultaneously by the VAP device, accelerometers, and a proven GPS-based speed sensing and data acquisition system. Data from the VAP device was compared to data collected by the reference instruments to assess timing, precision, and accuracy of reported parameters. Still images from the VAP video recording were compared with three dimensional laser scan data in order to analyze field of view. Several case studies are discussed, and some guidelines and cautions are provided for use of VAP data in accident reconstruction applications.

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.

Data regarding the characteristics of left turns and lane changes performed by articulated tractor semitrailer combination vehicles in urban environments are presented. Previous studies have quantified acceleration rates for tractor semitrailers travelling straight, and for automobiles making left turns, but there is a gap in the literature regarding heavy vehicle acceleration during left turns. Likewise there is a lack of published data regarding the duration of lane changes made by these vehicles at highway speeds. Left turns were studied at a four-way stop-sign controlled intersection with a high volume of heavy vehicle traffic. Markings were made on the roadway corresponding to three left turn paths of varying radii. Intervals leading up to and along the marked paths were measured and painted on the roadway. The motion of each tractor semitrailer that made the subject left turn was recorded by video.

There is a continuing debate in the scientific literature and among policy making bodies regarding the role of roof crush in the causation of rollover accident injuries. A question arising from field studies is whether the correlation between roof crush and injuries occurs because roof crush causes injuries or because roof crush is associated with accident severity, which is related to injury potential. Recent literature is reviewed to address this question. The Malibu rollover tests have been criticized for the level of “potentially injurious impacts” measured in the Hybrid III dummies used in these studies. Additionally, it has been asserted that the Hybrid III neck is excessively stiff in compression and that experimental testing with the Hybrid III produces results that are not representative of human occupant responses.