REFERENCE ROAD SURFACES FOR USE IN TIRE/ROAD NOISE MEASUREMENTS. REPRINT FROM THE 1985 INTERNATIONAL CONFERENCE ON NOISE CONTROL ENGINEERING (INTER-NOISE 85) IN MUNICH, FEDERAL REPUBLIC OF GERMANY, 18-20 SEPTEMBER 1985

The group of rapporteurs on brakes and running gear (grrf) within the ECE has established an ad-hoc group on "measurement of tire/roads noise" which recently proposed three methods for tire/road noise measurements. These methods are: a conventional coast-by method, a trailer method and a laboratory drum method. The proposal includes the specification of two reference surfaces by measurement of their macrotexture. One is designed to excite maximum high frequency noise (smooth surface) and the other to excite maximum low frequency noise (rough surface). Macrotexture should be measured by profile registration and subsequent spectral analyses where the levels in two critical octave bands are required. When the surfaces do not correspond to the nominal texture values, a correction to the noise for deviating texture is applied. The background for this problem and some information on which the proposal is based are presented in this paper. (Author/TRRL)