Are Roundabouts Safer than Traffic-Lighted Intersections?

Roundabouts, the circular intersections where traffic flows in one direction at low speeds, might be significantly safer than traffic-lighted intersections. Converting an intersection that has traffic light into a roundabout has been found to reduce vehicle crashes with injuries or fatalities by 78%. The types of accidents that tend to cause the most injuries and fatalities are right-angle or T-bone crashes, left-turn crashes and head-on crashes. Roundabouts are designed so that all vehicles travel in the same direction, so the risk of these most-common, potentially serious crashes is decreased. A roundabout is a type of traffic circle, but not all traffic circles provide the same safety benefits, because some permit higher speeds.

More about roundabouts:

• About 50% of the world's roundabouts are in France.


• One study found that roundabouts might increase the risk of accidents involving bicyclists. About 26% of cyclist-related accidents in the study took place at roundabouts, compared with 6% at intersections that had traffic signals.


• Converting traffic-lighted intersections to roundabouts might reduce carbon monoxide emissions by as much as 29 percent by improving traffic flow efficiency and decreasing fuel consumption.