Assessing the Impacts of Pavement Surface Condition on the Performance of Signalized Intersections

Signalized intersections are one of the most dangerous places on the road network as they carry a very high crash risk. This may be exacerbated by inadequate pavement surface condition. The main objective of this study was to assess the effect of pavement surface condition (in terms of skid resistance, roughness and rutting) at intersections and approaches on users' safety. In particular, this paper studied the change in crash frequency for numerous signalized intersections before and after surface treatment. Around one hundred sites were selected based on historical crash incident data and pavement maintenance records. Pavement condition data was extracted for these sites one year before and one year after surface treatment. For all sites, a minimum of three years crash data was used before and after treatment. Reported in this paper are the findings of an assessment of the changes in crash rates, types and severity due to surface treatment. Overall, assessment of the effect of surface treatment revealed a statistically significant reduction in crash rates of 0.49 at 95% confidence level with a p value of 0.006, based on a paired t-test. Negative binomial regression analysis was performed using pavement condition data, traffic volume and speed limit as the predictor variables of crash frequency. The results showed that both traffic volume and the interaction between traffic volume and skid resistance were significant contributors to the crash occurrence. However, for after treatment no independent variable had a significant contribution to the crash occurrence.