In order to get well defined test conditions for tire noise, a method for characterization of the road surface with respect to tire noise generation is presented. The method implies that the power spectral density(PSD) of a measured road profile is computed for spatialfrequencies between 2 and 1000 cycles/meter (corresponding to wavelengths 1 - 500 mm). Analysis with frequency resolution corresponding to octave or thirdoctave bands is recommended.

The described method does not give a complete description of the road parameters influencing tire noise, but can be considered as an important partial solution.