Assessing the effectiveness of speed limit reduction in Edmonton: A case study analysis

Area of Science:

• Traffic Safety Engineering
• Urban Planning
• Transportation Policy

Background:

• Urban areas face challenges with traffic safety and driver behavior.
• Speed limits are a key factor influencing road safety outcomes.
• Edmonton, Canada, implemented a reduced default speed limit to address these concerns.

Purpose of the Study:

• To evaluate the impact of lowering the default speed limit from 50 km/h to 40 km/h on traffic safety and driver behavior in Edmonton.
• To assess the effectiveness of speed limit reduction strategies in urban environments.

Main Methods:

• A before-and-after study with a comparison group approach was used.
• Collision data was analyzed for pre-COVID, COVID, and post-implementation periods.
• Speed surveys were conducted on 219 road segments before and after the speed limit change.
• Two-sample t-tests were employed to analyze speed data.

Main Results:

• A statistically significant 25% reduction in overall collisions and a 31% reduction in injuries and fatalities were observed.
• Average and 85th percentile speeds significantly decreased, with 53% of surveyed locations showing reduced driver speeds.
• Greater speed reductions were noted on local and narrower roads compared to collector and wider roads.

Conclusions:

• Reducing the speed limit effectively lowers vehicle speeds and decreases the number of traffic collisions.
• The findings provide a framework for municipalities to assess the efficacy of speed limit reduction programs for safer roads.
• The study highlights the positive impact on road users, including drivers, pedestrians, and cyclists.