Citation

Reust TJ, Morgan JM. Collision 2006; 1(1): 9-15.

Copyright

(Copyright © 2006, Collision Publishing)

DOI

unavailable

PMID

unavailable

Abstract

Many 1999 and newer General Motor vehicles have an event data recorder (EDR) that can record data which includes pre-event speed. The EDR is incorporated into the air bag system sensing and diagnostic module (SDM). In this study, the accuracy of the vehicle-reported speed was tested during acceleration, coasting, braking and yaw at speeds between 1 to 90 miles per hour. The accuracy was also tested during heavy acceleration, when an undersized spare tire was mounted on the drive axle and with tires having new and worn tire tread depths. The vehicle-reported speed was compared to the speed measured by a calibrated GPS speed measuring system. The results showed that the vehicle-reported speed matched well during acceleration and coasting, underestimated the speed during braking and underestimated the speed during a yaw event. Information downloaded from a SDM after an accident event can be used in conjunction with conventional methods of accident reconstruction to evaluate the event. To date, only a limited study of the SDM-reported speed accuracy has been reported.