This paper analyzes the effect of groove dimensions (width, depth, and spacing) of transversely grooved pavement surface on hydroplaning using a three-dimensional finite-volume hydroplaning simulation model. Groove widths varying from 2 to 10 rum, groove depths from 1 to 10 nm. and center-to-center spacings from 5 to 25 mm are examined. The effectiveness of a pavement groove design against hydroplaning can be assessed by its ability to raise the hydroplaning speed, which is the vehicle speed at which hydroplaning occurs. It is found that the hydroplaning speed can be raised by increasing the groove depth and width, and decreasing the groove spacing. thereby reducing the risk of hydroplaning occurrence. Among the three groove dimensions (i.e., width, depth, and spacing), changes in groove width is found to have the most significant effect, followed by groove spacing and groove depth. This paper next proposes an analytical procedure for the design of transverse pavement grooving using the simulation model based on the concept of risks of hydroplaning. An illustration of the proposed design procedure is presented in this paper, using a wet-weather freeway vehicle speed distribution. to determine the transverse pavement grooving designs for different risk levels from 0.001% upward. The design concept also allows one to assess the hydroplaning risk level of an existing transversely grooved pavement surface or a proposed groove design, with known wet-weather traffic speed distribution and water film thickness.
