Impact of Skid Resistance on Dry and Wet Weather Crashes

Abstract

The safety of a pavement surface can be characterized by properties such as skid resistance and texture. All pavement surfaces should be constructed and maintained such that they meet the friction demand of the roadway. Decades of research suggest that skid resistance is most critical on wet pavements; therefore, most highway safety management decisions are often made based only on wet pavement crashes. However, recent studies have found that skid resistance may also impact crash risk on pavements that are dry. Since pavements are dry more often than wet, management decisions based only on wet crashes are formulated from smaller data sets. If skid resistance also has impact on crash risk on dry pavements, then considering dry crashes in highway safety management can increase the number of crash observations, which could improve safety analysis, leading to better maintenance decisions. This study used visual and regression analyses to investigate the relationship between skid resistance and crash occurrence for both dry and wet conditions. Figures were developed to visually illustrate the crash–friction relationship. Statistical regression was used to generate crash models, and the estimated regression coefficients were used to evaluate whether there was a statistical relationship. The findings show that skid resistance influences crashes in both dry and wet conditions, but there is greater impact in wet weather.