A Method for Rating the Skid Resistance and Micro/Macrotexture Characteristics of Wet Pavements

A method is developed from combined viscous-dynamic hydroplaning theory to rate the skid resistance of wet pavements in terms of pavement microtexture and macrotexture drainage coefficients derived from full-scale tire-pavement friction tests. The friction tests can be conducted using any of the conventional tire test operating modes such as braked rolling, yawed rolling, or locked-wheel sliding. Once the drainage coefficients have been established for a wet pavement surface by friction test in a particular tire operating mode, the method can be used to predict friction coefficients on the wet pavement surface for the other tire operating modes, as well as friction coefficients for different-size tires and inflation pressure conditions. The procedure for using the method is described and examples are given. The method is used to evaluate the skid resistance, microtexture, and macrotexture characteristics of 83 highway pavements in Switzerland which were tested by The Institute of Technology (ISETH) using a skiddometer (locked-wheel test mode) over a 40 to 100-km/h speed range. The results obtained are compared with British pendulum, sand patch, and outflow meter tests of pavement surface texture also performed by ISETH on the same 83 highway pavements. Comparison with experimental data shows that the method gives reasonable estimates of friction coefficient for both aircraft and automobile tires for the examples cited.