Evaluating the Combined Effects of Friction Coefficient and Texture Depth of Asphalt Concrete Pavement on Freeway Accidents

Many studies have been conducted focusing on the effects of friction coefficient or texture depth on the highway accident risk. However, combined effects of these parameters have not been still addressed. In this research the interaction between friction coefficient, texture depth and accident rate in 30 freeway sections were examined. The accident data were gathered and an apparatus was designed to measure friction coefficient. A nonlinear regression analysis was performed and a combined exponential model was obtained. The results indicated that despite cross correlation between friction coefficient and texture depth, thess parameters have some independent effects on accident rates which can be used to decrease freeway accidents significantly.