Abstract Manager

This presentation outlines the objectives, discoveries, and recommendations from the City of Toronto Left-Turn Calming (LTC) Pilot project. The initial part delves into the overarching Vision Zero goals, addressing left-turning collisions, and exploring various LTC installations, both quick-build and permanent. The subsequent part covers the preliminary findings and recommendations from the before-and-after evaluation.

The City Council endorsed the Vision Zero Road Safety Plan in June 2016 and its subsequent update in July 2019. This comprehensive action plan aims to reduce traffic-related fatalities and serious injuries in Toronto, prioritizing the safety of vulnerable road users, such as pedestrians, cyclists, older adults, and school-age children.

Left-turn collisions at signalized intersections constitute a significant portion of accidents in Toronto, resulting in fatalities or serious injuries for pedestrians (18%) and cyclists (8%). High-speed left turns pose a particular risk at wide suburban intersections, where drivers can gain speed while completing a left turn with a wide radius.

One initiative under Toronto's Vision Zero Road Safety Plan is the left-turn calming pilot project, designed to proactively reduce the risk of left-turn collisions at signalized intersections. Left-turn calming treatments involve quick-build materials like rubber humps/bumps and permanent fixtures such as mountable concrete islands and asphalt, strategically placed along the centerline of an intersection approach to reinforce it before the crosswalk. These treatments aim to lower turning speeds, reduce conflicts, mitigate failure-to-yield crashes, and enhance the visibility of pedestrians and cyclists.

Due to the skewed traffic volume during the pandemic, Phase one of the pilot was inconclusive. In Phase 2, which commenced in 2023, six additional intersections were treated with left turn calming. Three used temporary materials, while the remaining three employed permanent materials. Site selection was based on historical pedestrian collisions, those resulting in fatalities or serious injuries, and past In-Service Safety Reviews.

In August 2023, a before-and-after evaluation commenced to assess the effectiveness of left-turn calming in Toronto. The study included six new treatment sites and two control sites. Collected data underwent processing and transformation using Video Analytics. Three surrogate safety indicators, encompassing vehicle left-turning speed, the left-turning vehicle yield rate to pedestrians, and conflicts between vulnerable road users and vehicles in terms of post-encroachment time (PET), were employed to evaluate the effectiveness of temporary and permanent left-turn calming treatments. Recommendations for future use cases of left-turn calming will be based on the results of this before-and-after evaluation.