This International Standard specifies the essential characteristics of a test surface intended to be used for measuring vehicle and tyre/road noise emissions. The surface design given in this International Standard: - produces consistent levels of tyre/road sound emission under a wide range of operating conditions including those appropriate to vehicle sound testing; - minimizes inter-site variation; - provides minor absorption of the vehicle sound sources; - is consistent with road-building practice. NOTE For the purposes of this International Standard, the terms noise and sound are used interchangeably.