Texture of road surfaces - methods of measurement, parameters evaluation and its influence on the tire/road noise

Paper presents methods and indexes of evaluation of road surfaces texture. Measurements of the texture depth (HP), the friction coefficient ^i, the mean profile depth (MPD) and the tire/road noise (CPXI) were conducted along tested surface segments. Texture profiles elaborated on the results of tests using the stylus profilometer and the stationary laser profilometer determined basis for calculation of the mean absolute profile deviations R a and the mean square profile deviations R ms . Relationships between parameters characterizing the road surface texture were established in the tests. A comparative analysis of measurement methods (MPD) using the stylus profilometer and the laser profilometers was performed. The paper presents the texture spectra of tested surfaces in the range of the wavelength from 2 to 250 mm, macrotexture and megatexture as well as for the wavelength 5 and 80 mm.