CITY OF CALGARY SPEED REDUCTION MEASURES
By: Boris Lam – Engineer-In-Training, Mobility Safety
Bio:
Boris Lam is an Engineer-in-Training specializing in Traffic Safety with the City of Calgary, bringing over three years of experience in the field. He holds a Bachelor of Science degree in Civil Engineering with a minor in Transportation from the University of Calgary. Boris joined the City of Calgary in 2022, where he focuses on enhancing traffic safety initiatives. Prior to this, he gained valuable experience through an internship with the City of Edmonton in a traffic safety role, as well as a project management position with Kettle River Contracting Ltd., where he further developed his expertise in managing projects.
Abstract:
In 2018, the City of Calgary adopted Vision Zero and, in collaboration with the Calgary Police Service, launched the Safer Mobility Plan to enhance road safety and reduce fatalities and serious injuries. A key component of the plan was the introduction of speed reduction measures, including lowering the default speed limit to 40 km/h on all unposted and residential roads in 2021. Additionally, many collector roads were assessed for speed limit reductions based on average and 85th percentile speeds, with further traffic safety measures introduced where needed. Early evaluations showed a modest but impactful reduction in speeds, contributing to improved safety, particularly for vulnerable road users like pedestrians and cyclists. This initiative aims to foster a safer, walkable, and community-oriented Calgary through ongoing road assessments, speed reductions, and the implementation of traffic calming measures.
Speed Reduction in Calgary
In 2018, the City of Calgary adopted Vision Zero. In collaboration with the Calgary Police Service, they developed the Safer Mobility Plan—a comprehensive initiative aimed at enhancing road safety for all residents. The Safer Mobility Plan focuses on minimizing fatalities and serious injuries, building safer communities, and fostering a culture of safety on Calgary’s roads.
A key element of this plan is the introduction of speed reduction measures. In 2021, Calgary lowered the default speed limit across all unposted and residential roads to 40 km/h. The city also implemented further reductions on many collector roads, based on the same criteria used for residential areas. This initiative was part of a broader city-wide assessment of Calgary's roads, which considered average and 85th percentile speeds over the past five years. Roads where the average speed was below 45 km/h and the 85th percentile speed was below 55 km/h were eligible for a reduced speed limit. By aligning speed limits with actual driving behaviour, the City anticipated higher compliance—since most drivers were already travelling below the previous 50 km/h limit in community settings.
Figure 1. Palliser Drive S.E. reduced speed limit to 40 km/h.
For collector roads where the average speeds were equal to or slightly higher than the set threshold, additional traffic safety measures were introduced. For example, along with a speed limit reduction to 40 km/h, the road geometry could be altered utilizing temporary or permanent traffic calming measures, such as curb extensions.
Figure 2. Intersection of Erin Woods Drive S.E. & Erin Park Close S.E. prior to traffic calming
Figure 3. Intersection of Erin Woods Drive S.E. & Erin Park Close S.E. with temporary traffic calming curb extensions.
Figure 4. Intersection of Erin Woods Drive S.E. & Erin Park Close S.E. converted into permanent curb extensions.
An early evaluation conducted on 16 collector roads showed a 2 km/h reduction in both the average and 85th percentile speeds. While modest, even a small reduction in speed can significantly lower the risk of fatal and serious injury collisions, particularly for pedestrians. By slowing down traffic, drivers have more time to react, improving vehicle control and reducing the severity of potential collisions. These measures not only help protect pedestrians, cyclists, and other vulnerable road users but also promote safer driving behaviours.
In conclusion, these initiatives, along with ongoing assessments, such as safety audits and public education campaigns, are designed to make Calgary’s streets safer and more walkable. By prioritizing speed reduction and implementing traffic calming measures, the Safer Mobility Plan not only improves road safety but also fosters a community-oriented, pedestrian-friendly environment.