Traffic specialist, Alaska Department of Transportation and Public Facilities, Juneau,
Associate director, Texas Transportation Institute, College Station,
Professor of civil engineering, Texas A&M University, College Station, Tex.
Pages: 16 Published: Jan 1983
A comprehensive series of experiments is reported involving a variety of full-scale highway pavements and various automobile tires. Test condition variables include vehicle speed, tread depth, water depth, and pavement inundated length.
Extensive test data are shown which define the tire forces encountered during partial and full dynamic hydroplaning as a function of the ASTM E 274 skid number. This enables an engineer to better interpret the actual friction available under specified conditions and shows vividly one reason it is so difficult to relate wet weather accident frequency to ASTM skid numbers.
In the final section of this paper 27 tests in selected water “puddles” are reported. These tests show that loss of tire/pavement contact can occur during puddle traversal and asymmetrical drag forces can develop which have the potential for precipitating a vehicle loss of control. These puddle depths range from zero on the outer edges to 28.5 mm (1 ⅛in.) in the deepest part. Drag forces up to 135 kg (300 lb) were measured.
It is illustrated that hydroplaning drag forces, in some cases coupled with loss of pavement contact due to hydroplaning, may pose a hazard to drivers who exceed a reasonable speed during wet weather.
hydroplaning, skid number, available friction, driver requirements, vehicle stability, hydrodynamic drag, tire-pavement interaction, tires
Paper ID: STP28522S