Aquaplaning Tests, 1967 to 1969. Investigation of Braking Action Developed by Motor Car Wheels

摘要

The National Swedish Road Research Institute has carried out an investigation dealing with the reduction in braking action on water covered road surfaces. An account is given of the theories of friction involved in rubber and in materials which are rigid in comparison to rubber. A review of the existing theories of aquaplaning is followed by definitions of the concepts of inertial aquaplaning and viscous aquaplaning. Field tests have been carried out with a friction test vehicle constructed at the Institute. The tests have shown that the braking action on a road surface completely covered with water is substantially reduced compared to the braking action on the same surface in the merely wet condition. This decrease takes place as soon as the speed exceeds a certain definite value. The decrease in the braking action occurs at a higher speed if the pavement surface is made rougher and if the tire is provided with a more effective tread pattern. A greater effect on the braking action is produced by increasing the roughness of the road surface than by improving the tread pattern of the tire.