Safety Performance of Experimental Pavement Types in California Using Before-and-After Comparisons

This study focused on safety performance of new pavement surface types. Open graded or coarse- textured roadway surfaces are advisable for high-speed, wet-weather traffic conditions. They provide drainage relief at the tire-pavement interface, reduce the steepness of the speed gradient, decrease the likelihood of hydroplaning, minimize splash and spray, reduce the glare from wet pavements, and improve high-speed skid resistance. Before-and-after comparisons using historical collision data from California Traffic Accident Surveillance and Analysis System (TASAS) were conducted to assess the safety performance of three types of experimental pavement: open- graded asphalt concrete (OGAC), groove pavement (GP), and rubberized open-graded asphalt concrete (R-OGAC) projects implemented in recent years. Because these new types of pavement surfaces are expected to improve drainage, wet pavement related collisions were considered target collisions and analyzed in the before-and-after study. Our findings indicate that resurfacing with OGAC significantly decreased the number of wet-related collisions. However, no significant conclusions were drawn from the results of resurfacing with GP and R-OGAC, due to the lack of sufficient data. While further research is needed, findings from this current study suggest that new pavement types such as OGAC can improve the safety performance of roadways.