Road Weather Management Program
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Best Practices for Road Weather Management Version 2.0


Prediction of Wet-Pavement Skid Resistance and Hydroplaning Potential


The current means of predicting the skid resistance of a wet pavement and the speed at which hydroplaning would occur are based on empirical models or relationships derived from experimental studies. These model and relationships are applicable only for the conditions specified, and extrapolations beyond the applicability range of parameters (e.g. range of vehicle speeds, tire loads, tire inflation pressures, water-film thickness, types of tires and pavement surfaces) are not advisable. Such restrictions could be overcome by developing an analytical model derived based on theoretical considerations. An analytical model would also provide a more in-depth understanding of the relative influence of different parameters. This paper presents a three-dimensional finite-element model to predict wet-pavement skid resistance and hydroplaning speeds under different magnitudes of passenger car wheel load, tire inflation pressure, water-film thickness and vehicle speed. The analysis shows that the hydroplaning speed increases (i.e. hydroplaning risk decreases) with wheel load and tire inflation pressure, but decreases with the depth of water-film thickness. The skid resistance measured in terms of skid number decreases as the sliding wheel speed or the water-film thickness increases, but increases with the magnitude of wheel load and is affected marginally by the tire inflation pressure. Within the normal passenger car operation range of each of the parameters, the hydroplaning is affected most by tire inflation pressure, followed by water-film thickness, and is least influenced by the wheel load; while the skid resistance is most influenced by wheel sliding speed, followed by water-film thickness and wheel load and is least affected by the tire inflation pressure.


86th Transportation Research Board (TRB) Annual Meeting, National University of Singapore. For an electronic copy of this resource, please direct your request to

Date: 2007


Ong, Fwa


Pavement condition

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