This Technical Specification describes a method for determining the wet-road skid resistance of a surface by measuring the LFCD. The method provides a measure of the wet-road skid resistance properties of a bound surface by measurement of the longitudinal friction coefficient at a fixed slip ratio of 86 % and at a controlled speed. The method has been developed for use on roads, but is also applicable to other paved areas such as airports. This Technical Specification covers the following proprietary devices: RWSNL skid resistance trailer device, which has been developed by the Rijkswaterstaat in the Netherlands. The device uses a standard PIARC smooth test tyre being dragged over a pre-wetted pavement under controlled speed conditions while its running direction is parallel to the direction of motion and perpendicular to the pavement. Several RWS skid resistance trailer devices have been manufactured under license and operate in combination with variable towing vehicles.