Abstract:
Skidding on wet horizontal pavement curves is a major traffic safety
concern. Themaximum safe driving speed against skidding is an important threshold
for safe driving. However, because of the complex tire-pavement-fluid interaction
mechanism and the large number of variables involved (including curve geometric
parameters, pavement surface properties, properties of tire in motion, and water
film thickness), currently there is no practical working procedure that allows pavement
engineers to determine the maximum safe driving speed on a horizontal curve
under a given wet weather condition. This paper presents a finite element model to
predict the maximum safe driving speed on a wet curved roadway section based on
solid mechanics and hydrodynamics. The numerical simulation model was developed
and validated against experimental skid resistance values on slip angles from
0° to 90°. Based on skidding analysis, the maximum safe driving speed on a horizontal
curve is derived by comparing the available tire-pavement frictional resistance
and the required friction to prevent skidding caused by the centrifugal force of the
vehicle concerned. An illustrative case study is presented to compare the calculated
maximum safe vehicle speed with AASHTO design speed. The analysis presented
suggested that the proposed approach offers a useful tool to calculate maximum safe
speeds on in-service pavement curves for safe driving.
