This International Standard specifies the essential characteristics of a test surface intended to be used formeasuring vehicle and tyre/road noise emissions.The surface design given in this International Standard will:. produce consistent levels of tyre/road sound emission under a wide range of operating conditionsincluding those appropriate to vehicle sound testing;. minimize inter-site variation;. provide negligible absorption of the vehicle sound sources;. be consistent with road-building practice.NOTE For the purposes of this international standard, the terms noise and sound are used interchangeably.