Frictional behaviour of tyres on snow is important for vehicles. We made friction tests of rubber tread blocks, of different geometries and rubber formulations, on compacted artificial snow in a cold room using a linear tribometer. These tests show excellent agreement with outdoor vehicle tests. The friction coefficient (μ) for rubber decreases with increasing velocity because of a water layer formed by frictional heating. As glass transition temperature Tg of the rubber decreases μ increases, which correlates with the increased compliance of the rubber. At higher velocities siped tread-blocks show higher friction than blocks without sipes because of ploughing.