Identifying High Crash Signalized Intersections and Application of Highway Safety Manual Predictive Method to Reduce Crashes

Abstract

Road crash reduction depends on the precise identification of High Crash Locations (HCLs) and suggesting appropriate solutions and preventative measures. Though not all crashes are owing to defective characteristics of the roadway, a concentration of crashes at one location suggests that there may be a failure in the highway system. Identification of these HCLs can be achieved by detailed investigation of crash records, and further evaluations can then result in improvements that will decrease the number and severity of future crashes. The primary goal of this study is to identify HCLs in Duhok City and rank the signalized intersections using mathematical methods such as crash frequency method, crash rate method and critical crash rate method and identify possible treatments that reduce crashes at signalized intersections using the Highway Safety Manual. Distribution of crashes by type indicates that the rear end, angle, and sideswipe are common types of crashes that occur at these intersections. The results indicated that of intersections, Tax, Benavi 1, Benavi 2, Commerce, and Etite intersections are hazardous locations. The Highway Safety Manual (HSM) predictive method allows the design engineer in a road agency to estimate the measurable safety impacts of several design proposals and offer explanations for their design decisions. The results show that one approach/countermeasure to crash prevention may work effectively; however, a combination of approaches and/or countermeasures will have a greater impact. Furthermore, the results showed that there is a significant effect on the probable average crash frequency after all treatments applied at intersections.