Pavement Skid Number and Horizontal Curve Safety

Abstract

According to the National Highway Traffic Safety Administration's Fatality Analysis Report System, more than 25 percent of fatal crashes occur on horizontal curves. High Friction Surface Treatments are an innovative, cost-effective, and sustainable means of improving roadway safety, which could improve the safety of this alignment. This research involved a comprehensive review of crash data to identify the correlation between pavement skid number, roadway curvature degree, crash rate, and crash severity. The dataset showed that greater injury occurred on higher degrees of curvature, and lower skid numbers correlated to a higher percent of wet road crashes. Also, around a skid number of 55, an increase in skid number no longer resulted in decreased crash rates. The goal of this research is to use these correlations to develop Crash Modification Factor that would integrate pavement friction and horizontal curvature, to enhance the accuracy of the current Highway Safety annual performance function.