Updating Culvert and Storm Drain Design and Installation Methods
Authors: Catherine Earp , Rick Renna (FLDOT)
A cost effective design preference for widening roadway sections is to expand lanes to the outside with a continuous cross slope, rather than expand and slope lanes to the inside. This preference increases the water film thickness along the cross slope and raises concern regarding hydroplaning potential. FDOT and University of South Florida developed the software, HP, a hydroplaning assessment tool, to better predict hydroplaning potential using roadway parameters such as pavement type, pavement temperature, lane width, lane slope and longitudinal slope. The program has two components (1) a methodology to predict water film thickness (WFT) on the pavement being analyzed; and (2) a methodology to predict potential hydroplaning speed given the WFT determined. Hydroplaning potential is compared to the predicted driver’s speed, which is a factor of the design speed combined with the predicted driver’s speed reduction due to the visual impairment caused by a rainfall event. Predicted driver speed reductions were obtained using a driving simulator to measure driver’s response during simulated rain events. The results were calibrated to real-life driving data collected on Florida’s interstate system around the state. Analyzing the hydroplaning potential allows designers to better quantify the risk associated with wide section roadways having a continuous cross slope and decide when it would is beneficial to break the slope to decrease risk. Identification of recently approved, wider Florida typical sections with design speed restrictions will be discussed and complemented by an HP demonstration and sample problem discussion.
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How to Cite: Earp, C. & Renna, R. (2014) “Analyzing Hydroplaning Potential on Wide Roadways”, National Hydraulic Engineering Conference 2014. 1(2014).