NHTSA (National Highway Traffic Safety Administration) Heavy Duty Vehicle Brake Research Program Report No. 4 - Stopping Capability of Hydraulically Braked Vehicles. Volume 1. Technical Report

摘要

Twelve hydraulically braked trucks representing a broad range of vehicle and braking system configurations were extensively tested to determine their braking performance. Limited tests were also run on a school bus. Gross vehicle weight ratings of the test vehicles ranged from 14,800 to 46,000 lbs and most of the vehicles were equipped with 1981-82 braking systems. Five of the twelve trucks were retested with upgraded 1983-84 braking systems. Straight line stopping performance was determined utilizing a modified FMVSS No. 105 test sequence with tests added to provide 20 mph stopping distance data, wet surface stopping data, braking distribution data and booster performance data. Several of the trucks and the school bus were also tested to evaluate their controllability during braking in various types of maneuvers. These maneuvers were run on a wet sealed asphalt surface and included braking in a turn, braking in a lane change, and braking in a straight lane with a split coefficient friction surface. Some braking in a turn was also run on ice. Two of the vehicles were modified with an adjustable braking distribution system and were tested to determine stopping performance in braking and turning maneuvers as a function of braking distribution. The report presents a description of the test program and an analysis of the results. It includes descriptions of the test vehicle performance summaries and graphs; and discussions of the results.