Evaluating the Impact of Tire Conditioning Distance on Roadway Skid Resistance

Abstract: Skid resistance is a critical factor in pavement safety, influencing the ability of vehicles to maintain control under braking and steering. Among the various devices used to measure this parameter, the Locked-Wheel Skid Tester (LWST) is the most commonly deployed due to its proven reliability and correlation with vehicular accidents. This research addresses the challenges associated with the tire conditioning distance required by ASTM standards E274, E501, and E524, which mandate that new tires be conditioned by running them on a test vehicle under normal traffic conditions for at least 200 miles at their rated load and inflation pressure before use in testing. Such extensive conditioning is often impractical for routine operations, prompting a need for a more feasible approach.

Despite thorough literature reviews and consultations with industry experts, no definitive studies directly addressed the impact of reduced conditioning distances on skid test accuracy. Discussions with tire manufacturers and an analysis of practices in various states confirmed a widespread adherence to the 200-mile standard. This gap in the literature and the uniformity of practice underscored the necessity for empirical research. Thus, the study implemented a practical investigation, testing shorter conditioning distances to determine their effect on the reliability of friction measurements.

This study presents the outcomes of these empirical tests and proposes adjustments to the current standards, aiming to align the theoretical understanding of tire behavior with operational efficiencies in pavement testing protocols.