This Technical Specification describes a method for determining the skid resistance of pavements by measurement of the longitudinal friction coefficient LFCA. The method provides a measure of the wet skid resistance properties of a bound surface by measurement of the longitudinal friction coefficient using a locked wheel trailer with a slip ratio of 100 % (locked wheel: standard), or a variable slip between 0 % to 100 % (for research measurements). Within this method the steady-state friction on a braked test wheel is measured. The test tyre is dragged over a pre-wetted pavement under controlled load and constant speed conditions while the test tyre is parallel to the direction of motion and perpendicular to the pavement. This technical specification covers the operation of the ADHERA device.