The influence of road surface texture on the skid resistance under wet conditions

Abstract

Due to their influence on traffic safety, skid resistance and drainage are important surface properties of a road and their optimization and durability is still focus of ongoing research. Under wet conditions, these two characteristics are connected as a wetted road cannot provide a sufficient skid resistance without a working drainage system. The wet friction is mainly affected by the road surface geometry and the water depth. Herein, we describe a novel numerical approach to study the influence of the surface texture – mainly the microtexture – on the wet friction coefficient. This method is based on the hysteresis effect, which is the main friction force on rough surfaces under wet conditions. We therefore use an already established friction model for dry surfaces and extend its range of application by an additional consideration of water films. A drainage model has been developed to calculate the water film thickness for a given road surface and geometry (pavement surface runoff model) as systematic measurements of water film thicknesses in situ are difficult. The water depth determines the number of contact points between the pavement and the tyre. Based on three-dimensional measurements of a surface texture, the friction coefficient is calculated. By this newly developed model approach, it is possible to identify the main factors influencing wet skid resistance in regard to the pavement surface microtexture and the water film thickness.

Advancing road safety assessment with digital holography: a study on skid resistance of asphalt pavements

“…Additionally, the major function of microtexture for preventing pavement from skidding is to produce adhesion friction. The dry contact area between the tire and the pavement grows and the hydrodynamic lubricating effect between the contact interfaces decreases as the microtexture of the pavement becomes sharper, making it easier to puncture the water film in a wet state [1,2]. Therefore, road authorities regularly assess these aspects and undertake necessary maintenance measures.…”

Study on the Attenuation of Long-Term Skid Resistance of Asphalt Mixtures under Aeolian Sand Conditions

“…However, in reality, the road surface texture is inevitably affected by external environmental factors, such as rainfall, snowfall, icing, and other pollutants, and the presence of these adherents affects the friction between vehicle tires and the road surface [8,9]. Changes in climate and traffic volume have a significant impact on the pavement texture [10][11][12]; rainfall seriously affects the anti-skid performance of the pavement [13][14][15]; and the rainwater present becomes a lubricant between the tire and the pavement, with the water film producing dynamic water pressure on the wheels, so that the tire adhesion to the pavement decreases as the thickness of the film increases, leading to a greater decline in the anti-skid performance [16,17]. Under freezing conditions, ice and snow fill the road surface voids and reduce the depth of the structure, hindering the direct contact between the tires and the road surface, and the anti-skid performance is then seriously reduced [7,[18][19][20], resulting in the loss of the original stability of the vehicle braking and an increase in the braking distance, which poses a potential hazard to driving safety.…”

Assessing Surface Texture Features of Asphalt Pavement Based on Three-Dimensional Laser Scanning Technology

“…Furthermore, microtexture mainly provides an adhesion friction component for pavement skid resistance. The sharper the microtexture is, the more easily the pavement texture punctures the water film in the wet condition, which increases the dry contact area between the tire and the pavement and reduces the hydrodynamic lubrication effect between the contact interfaces [3]. The macrotexture depends on the gradation design and construction quality, while the microtexture is related to the mineral composition and crushing process of the aggregate.…”