Tests were devised using an Accelerated Polishing Machine and a friction measuring device, a Skid-Tester (otherwise known as the Pendulum, also manufactured and supplied by Wessex), to determine a Polished Stone Value.
These developments have resulted in a simple and inexpensive procedure to determine skid resistance in advance of a road being built. Use of the PSV tests in road construction has had a major influence in the reduction of accidents.