A surrogate safety assessment of scrambled phase intersections

Traffic safety remains a top priority for policymakers and researchers, prompting numerous investigations to enhance safety for all road users, particularly pedestrians. This paper evaluates the safety impact of implementing scramble phases at intersections with a high concentration of vulnerable road users in Edmonton, Canada. The study spans three periods: prior to the scramble phase installation, immediately post-installation, and 6 months post-installation. The evaluation employs two key methodologies. Firstly, it observes the frequency of right-turn-on-red violations to assess driver behaviour. Secondly, the study investigates the frequency of serious conflicts, utilizing safety indicators such as time to collision, time difference to point of intersection, and distance between stop position and pedestrian. The findings suggest that introducing scramble phases positively impacts intersection safety, notably reducing severe conflicts and total right-turn-on-red violations. These results offer valuable insights for policymakers and researchers working towards safer urban traffic environments.