Safety Benefits of Traffic Calming

This study was conducted to determine whether there are quantifiable collision-reduction benefits that result from traffic calming. Traffic calming is typically implemented to address speeding and external traffic concerns. It is intuitively recognized that successful traffic calming would therefore result in safety benefits. This research attempted to determine whether these safety benefits are measurable and significant. Four local traffic-calming projects in the Greater Vancouver area were reviewed as part of the research. All four of the projects achieved reductions in collision frequency, severity, and the annual collision claim costs. The magnitude of these benefits varied among the projects, with an average 40 percent reduction in collision frequency and 38 percent reduction in the annual claims costs. A total of 85 case studies from Europe, Australia, and North America were reviewed to determine the safety benefits of traffic calming as measured by other jurisdictions. The international case studies in which more than five precalming collisions per year occurred were analyzed separately. In this group of 15 studies, the decrease in collision frequency ranged from 8 percent to 95 percent. The implementation of traffic calming involves participation on the part of the general public, local municipalities, and emergency response organizations. The planning, engineering, and public consultation process are all a necessary part of the process to improving neighborhood livability. The results of this research provide evidence that the safety benefits of traffic calming are both quantifiable and significant.