Introduction

The National Highway Traffic Safety Administration (NHTSA) reported that in 2004, 416,000 large trucks were involved in traffic crashes in the U.S., that a total of 5,190 people died (12% of all the traffic fatalities reported in 2004) and an additional 116,000 were injured in those crashes. One out of eight traffic fatalities in 2004 resulted from a collision involving a large truck. In a widely cited study by Jones and Stein (Jones I. and H. Stein, Defective Equipment and Tractor-Trailer Crash Involvement. Accident Analysis and Prevention 21:469-81, 1989), it was reported that brake defects were quite common and were found in 56% of the tractor-trailers involved in crashes. In the more recent Large Truck Crash Causation Study sponsored by DOT, it was concluded that 29.4% of all large truck crashes involved brake failure, brakes out of adjustment, or other brake related issues.

Compounding the brake defects issue even more is the fact that although original equipment (OE) brakes must comply with federal motor vehicle safety standards which specify maximum stopping distances according to vehicle weight, loading, pedal effort (with and without power assistance) and brake condition (green and burnished linings), there are no federal performance standards for aftermarket (AM) brake linings. It is typically assumed that replacement AM brake linings perform the same as or better than the OE brake linings on a vehicle. Unfortunately, there is currently no methodology or rating system available that can assure OE-equivalent brake performance from AM brake linings.