Basic Test Methods for Evaluating Tire Traction

The paper describes some of the basic testing methods used to evaluate the wet traction characteristics of a passenger car tire. The scope of the methods presented is limited to outdoor testing techniques, for temperatures above freezing, utilizing conventional vehicles or special towed trailers. The tests are defined in relation to the tire's singular or combined operating modes -- driving, braking, and cornering. Factors affecting test accuracy, repeatability, and correlation are reviewed, including the use of control tires. Also shown are illustrations of typical tests, test sites, and related equipment.