Abstract Manager

Speed limit reduction is a key action outlined in the City of Edmonton’s Safe Mobility Strategy 2021-2025, which is designed to accelerate our journey to Vision Zero by 2032. In August 2021, Edmonton implemented a city-wide reduction in the default speed limit from 50 km/h to 40 km/h, which included all residential local roads, the majority of residential collector roads, and arterial roads in the downtown area. Lower speeds mean greater protection for all road users and particularly those most vulnerable including pedestrians, cyclists, and users of micro-mobility. 

Edmonton conducted a comprehensive evaluation that determined the impact of the new speed limit on speeds and collisions, revealed where the new speed limit was most effective, and identified locations that would benefit from future upgrades to improve compliance. The before/after analysis included collecting speed data at 219 locations, as well as collision data across two time periods: before-implementation (August 2019 - July 2021), and after-implementation (August 2021- July 2022). 

First, the study showed the impact of the reduction:  

• Statistically significant reductions in the overall number of collisions and in injuries and fatalities by 25% and 31%, respectively.

• Statistically significant reductions in the average and 85th percentile speeds by 1.1 km/h and 1.6 km/h, respectively.

• A change in percentage of drivers travelling above 40 km/h, 50 km/h, and 60 km/h.

Second, areas where the new speed limit was most and least effective were analyzed:

• Central core neighbourhoods had higher speed reductions, lower average speeds and higher collision reductions than other neighbourhoods.

• Grid neighbourhoods also showed higher speed reductions, lower average speeds and higher collision reductions than Cul de Sac neighbourhoods.

• Drivers did not adjust their speeds immediately when moving from a higher speed limit zone to neighbourhood roads. The analysis showed that entrance to neighbourhood segments of collectors had almost double the collision risk than internal collectors.

Third, future improvements for collector roads were identified:

• Long, wide, and uninterrupted roads, popular in Cul de Sac neighbourhoods, were identified as candidates for adaptable or permanent traffic calming to support drivers to slow down.

• Entrance points to neighbourhoods will receive 40 km/h speed limit signs in addition to traffic calming to remind drivers to slow down.

Despite limited design guidance for 40 km/h, the City has innovatively tested and trialed new approaches, yielding strong results.