Samenvatting
The coefficient of friction of a tyre on a wet road consists mainly of two components: an adhesion and a hysteresis component. These components will be most effective if there is no lubricating film between the tyre and the road surface. In the contact zone this film will be penetrated by road surface asperities and expelled through grooves in the tread profile. The expulsion of water and therefore the coefficient of friction will be highly influenced by the speed of the car. Other influencing factors are the road surface drainage capacity and some tread profile factors.