Safety
The first Minnesota modern roundabout was constructed in 1995. Since then, roundabouts have been built across the state by MnDOT, counties, and cities. There is no definitive count across Minnesota, but it is likely nearing 200 roundabouts across the state on all roads. They have become an increasingly popular intersection type by traffic engineers, communities, and transportation officials.
MnDOT's 2017 study of the traffic safety at roundabouts in Minnesota (PDF) examines the safety performance of roundabouts by comparing the before construction crash rates and the after construction crash rates and traffic volume data. Overall, roundabouts are performing well when looking at the crash reduction record. Roundabouts in Minnesota have had over an 80% reduction in fatal and serious injury crashes. At the time of this report, there still has not been a multi-vehicle fatality in a roundabout in Minnesota.
Other highlights include:
- An 86% reduction in the fatal crash rate at intersections where roundabouts have been installed. This includes all roundabout types (Single Lane, Unbalanced, and full Dual Lane Roundabouts). See Pages 6-7 for more information on roundabout types.
- An 83% reduction in the serious injury crash rate at intersections where roundabouts have been installed.
- A 69% reduction in the Right Angle crash rate at intersections where Single Lane Roundabout have been installed.
- An 83% reduction in the Left Turning crash rate at intersections where Single Lane Roundabout have been installed.
- A 61% reduction in the injury crash rate at intersections where Single Lane Roundabout have been installed.
- A 42% overall reduction in the injury crash rate at intersections with all types of roundabouts.