Effects of Pavement Macrotexture Depth and Skid Resistance on Crash Severity Rates

Abstract

Preventive pavement maintenance decisions in Jordan are normally made based on factors not related to traffic safety in particular. In rare cases, especially when serious crashes occur, such maintenance may be implemented in response to a public outcry. Ideally, it would be beneficial to include frictional and macrotexture measurements. This study aims to identify road sections that are likely to experience severe crash occurrences by using threshold levels of pavement texture and skid resistance. Several road sections with significant crash experience were included in this investigation. Field measurements of Average Pavement Macrotexture Depth (APMD) and British Pendulum Number (BPN) in the wheel path were collected and analyzed. The crash history of these locations in terms of fatal and personal injury accidents was documented. The researchers introduced a crash severity rate in terms of property damage only accidents per million of vehicle miles of travel (VMT). Regression analyses at a significance level of 0.05 were attempted relating crash severity rates (CSR) to the prevailing texture depth and the measured BPN. A CSR of 2.5 property damage only accidents per million vehicle miles of travel was used in this investigation to produce threshold levels of BPN and APMD. The resulting thresholds were a BPN of 40 and APMD of 0.3 mm. The collection of periodic BPN and APMD can be used to identify potential hotspots by predicting the corresponding crash severity rate. Thus, road agencies should be able to make sound decisions regarding corrective maintenance to promote safety in a timely manner.