Abstract
This paper describes experiments and methodology employed in an attempt to develop a system for the grading of wet tire traction. Data from instrumented vehicle experiments and the University of Michigan Highway Safety Research Institute mobile tire tester are used to support the conclusions. Three tire force measures obtained with the mobile tire tester-the peak longitudinal, peak free-rolling lateral, and locked wheel longitudinal coefficients of friction- are presented. The results indicates the feasibility of defining minimum wet traction levels for various tire-road interface properties.