Roundabouts help to reduce accidents, reduce congestion and improve traffic flow, and improve air quality.
Improve safety
Roundabouts help reduce the likelihood and severity of collisions because of low travel speeds at intersections, one-way travel, and no light for drivers to try to beat.
Studies by the Insurance Institute of Highway Safety (IIHS) and Federal Highway Administration (FHWA) show that roundabouts:
- Reduce overall collisions by 37%
- Reduce injury collisions by 75%
- Reduce fatality collisions by 90%
- Reduce pedestrian collisions by 40%
Conflict points are also reduced with roundabouts compared to traditional intersections.
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Reduce congestion and improve traffic flow
Roundabouts allow for continuous flow of traffic. Drivers are not required to stop - only yield - so the intersection can handle more traffic in the same amount of time.
Studies by the FHWA have found that roundabouts can increase traffic capacity by 30 - 50% compared to traditional intersections. The IIHS also found that roundabouts contributed to an 89% reduction in traffic delays.
Improve air quality
Roundabouts can help improve air quality by lowering vehicle emissions from idling. The IIHS found that installing roundabouts instead of traffic signals or stop signs reduces carbon dioxide emissions by 23 - 34%.