Hydroplaning Control on Multi-Lane Freeways

Adverse weather-induced wet pavement conditions represent a critical factor in roadway safety. This study examines the dynamic aquaplaning phenomenon along extensive, in terms of width, 4-lane freeway alignments, aiming to assess the key aquaplaning thresholds of water film thickness above the top of pavement texture (WFT) and aquaplaning speed (APS), respectively. In total, 75 4-lane freeway alignments were examined in accordance with the German (RAA, 2008) urban motorway design guidelines (EKA 3 Class). These alignments were combined with a selected range of additional parameters, based on balanced literature findings, involving pavement surface characteristics, vehicle, and user parameters, as well as various rainfall intensity rates, resulting in 6075 combinations in total. The aquaplaning assessment was conducted using the method developed by Gallaway, with the drainage path determined from the algebraic sum of the longitudinal grade and the superelevation rate within the 3D roadway geometry. The multiple linear regression analysis demonstrated high predictive accuracy for both WFT and APS parameters. The present research sought to quantitatively identify potential critical conditions associated with key roadway, user, and vehicle parameters, with the ultimate objective of supporting the development of evidence-based variable speed limits.