Commercial Drivers' Subjective Rating of Stopping Capability of Air-Braked Vehicles 2000-01-3475
A study was conducted to examine the ability of 132 commercial drivers to evaluate the stopping capability of air-braked vehicles. A systematic approach was taken at roadside inspection sites to interview commercial drivers, check the level of adjustment of service brakes, and measure the brake torque output of heavy trucks. Spearman rank-order correlations were performed to compare basic 10-point scales that were established to rate drivers' subjective rating of stopping capability with the applied pushrod stroke of foundation brakes and braking performance. No relationship was found between drivers' subjective rating of stopping capability and brake adjustment status. In contrast a significant, yet inverse, relationship was discovered between drivers' subjective rating and vehicle deceleration rates.