Commercial Vehicle Braking

NTRCI’s goal in Commercial Vehicle Braking is to provide research that can improve the safety and reliability of current commercial motor vehicles (CMVs) braking systems by investigating brake performance, analysis, modeling and other technologies. Our work is both theoretical and applied to include investigating friction components in use and assessing methods of evaluating brake performance using newer automated test equipment. Reducing the disparity between the stopping distances of heavy trucks and the lighter vehicles with which they share the road continues to be one of the National Highway Traffic Safety Administration's (NHTSA) high priority areas. Current truck designs typically take between 1.5 and 2 times as far to stop as passenger cars from highway speeds. Truck brake performance has been identified as a major factor contributing to crashes involving large trucks.

Development & Evaluation of Roadside Inspection Technology using a Multiple Plate Performance Based Brake Tester (MPPBT)

Faulty brakes are cited as a contributing factor in a large portion of highway crashes that involve commercial motor vehicles. However, existing brake inspection procedures carried out by state motor vehicle safety officers are so time-consuming that they are performed on only a tiny fraction of the commercial motor vehicles that are an ever-increasing presence on the nation’s highways. more...

Field Testing & Analysis of Braking Performance of In-Service Trucks

The National Highway Traffic Safety Administration (NHTSA) is on the verge of requiring that the stopping distance of new trucks be reduced up to 30 percent below current regulations, depending on the vehicle type. However, this regulation does not address the braking performance of trucks after they have entered into service. Further, the current in-service vehicle inspection procedure, as well as the required annual inspection of commercial motor vehicles (CMVs), may be missing a critical component of braking capability, that of the effectiveness of after-market or replacement brake linings, which have a direct impact on stopping capability. Inspection procedures for CMVs cannot assess the friction available at the pad versus drum (or disc) interface, and there are no data available on the criticality to safety of this aspect of the inspection process. The objective of this project is to obtain a data set of the stopping capability of in-service CMVs. more...

Heavy Single-Unit Truck Original Equipment and Aftermarket Brake Performance Characterization in Field, Test-Track and Laboratory Environments

Reducing the disparity between the stopping distances of heavy trucks and the lighter vehicles with which they share the road continues to be one of the National Highway Traffic Safety Administration’s (NHTSA) high priority areas. Current truck designs typically take between 1.5 and 2 times as far to stop from highway speeds, as do passenger cars. Truck brake performance has been identified as a major factor contributing to crashes involving large trucks. Analysis of the 2001 Fatality Analysis Reporting System (FARS) data shows that SUTs are involved in 27% of all fatal crashes which involve large trucks (GVWR > 10,000 lbs.) more...

Integrated Braking Systems Analysis and Modeling

The National Transportation Research Center, Inc., (NTRCI) initiated research into integrated braking systems safety research to support US DOT’s objective to reduce the number of fatalities and injuries in crashes involving heavy trucks by 50 percent by 2010. This research supports efforts to decrease the stopping distances of heavy vehicles from highway speeds by 30 percent, while maintaining vehicle stability and control. more...