The Traffic Injury Research Foundation (TIRF) undertook a research project to understand the effectiveness of posted speed limit reductions in partnership with SMATS Traffic Solutions. This project was funded through Transport Canada’s Enhanced Road Safety Transfer Payment Program (ERSTPP). As cities increasingly adopt lower speed limits to enhance road safety, this research offers critical insights into where these changes are most effective and how roadway design influences driver compliance.

The study is utilizing high-resolution big data from connected vehicles, including speeds, harsh braking and acceleration. By integrating these datasets, the project is observing changes in speeding behaviours before and after the lowering of speed limits and developing:

• Predictive Speed Models: Quantifying the expected reduction in average and 85th percentile speeds based on initial conditions.
• Infrastructure Analysis: Identifying specific roadway features, such as lane width and the presence of medians, that act as barriers to effective speed management.
• Safety Performance Functions: Utilizing surrogate safety measures to identify high-risk hotspots before crashes occur.