Pavement Grooving and Vehicle Hydroplaning

This paper presents an analytical study performed to analyze the effectiveness of different pavement grooving patterns in reducing vehicle hydroplaning potential (i.e. raising hydroplaning speed). Grooves are man-made macrotexture formed in pavement surface to increase resistance to skidding and hydroplaning. In pavement engineering, the mean texture depth (MTD) is commonly adopted to characterize macrotexture and used as a controlling parameter to help ensure that sufficient skid resistance is maintained for safe traffic operations. This practice has been established based on the knowledge that pavements with better macrotexture (i.e. higher MTD) suffer less skid resistance loss as vehicle speed increases. In contrast, the exact benefits of pavement macrotexture in reducing hydroplaning potential are not well understood. This study attempts to offer some explanations by using a validated computer simulation model to analyze the variation of hydroplaning speeds on pavements having different groove patterns and depths. Three patterns of grooved surface are examined: two patterns of unidirectional flow channels, i.e. transversely grooved and longitudinally grooved surface, and grid-pattern grooved surface that has two-directional flow channels. The results show that they display different hydroplaning-related behaviors, and the relationships between MTD and hydroplaning speed for the three cases also differ. Possible causes of the differences are identified by examining the development of hydrodynamic uplift forces, and the flow characteristics of the water-film at tire-pavement interface at the onset of hydroplaning.