1.1 This test method covers a procedure for measuring the driving traction of passenger car and light truck tires while traveling in a straight line on snow- or ice-covered surfaces.1.2 This test method utilizes a dedicated, instrumented, four-wheel rear-wheel drive test vehicle with a specially instrumented drive axle to measure fore-aft and vertical forces acting on a single driven test tire.1.3 This test method is suitable for research and development purposes where tires are