Hydrological Considerations in Designing Roadways: Avoiding Hydroplaning

Abstract

Safety on highways is essential, but high water levels on lanes risk that. Drainage structures are mostly concerned with water spread at sideways and ignore the build-up flow on the surface. This study addresses whether optimizing cross slopes prevents hydroplaning. Water depths obtained using kinematic wave equation were tested against several studies for verification. Wide range of rainfall intensities and cross slopes was tested. Findings revealed that cross slope optimization for grades up to 10% prevents hydroplaning for intensities below 250mm/hr with widths up to 15m. The study shows cross slope optimization must be considered simultaneously with inlet design work.