Development of a new analytical water film depth (WFD) prediction model for asphalt pavement drainage evaluation

Pavement drainage Evaluation is conducive to reduce hydroplaning risk. Empirical Water Film Depth (WFD) models are low accuracy and have limited application scope. This study develops an analytical WFD model by simulating the dynamic of sheet flow. Based on the field data of 10 test sites the analytical model and two empirical models are applied for WFD prediction. Refer to the field measured WFD, correlation tests are applied, and the findings include: the intervening factors on WFDs are ranked as follows rainfall intensity, pavement permeability, flow path length, flow path slope, and texture depth; the proposed analytical model is more accurate than Gallaway model and PAVDRN model. The significance is twofold. First, accumulated rainwater is involved in WFD estimation. Second, the hazardous ponding location is identified, so that pavement engineers can take remedial measures to reduce potential hydroplaning.