Studies show that replacing a traffic signal or stop sign with a roundabout increases traffic safety at intersections “because the roundabout’s tight circle forces drivers to slow down, and traffic flows in the same direction,” the Insurance Institute for Highway Safety (IIHS) reports.
Roundabouts (not to be confused with traffic circles or rotaries, see below) “essentially eliminate” the most dangerous types of intersection crashes – right-angle, left turn, and head-on collisions,” IIHS says. “And the low speed rear end crashes and side swipes that sometimes do occur are unlikely to result in serious injury.”
Roundabouts, which are more common in Europe than the U.S., also improve traffic flow and reduce idling, thereby reducing fuel consumption and emissions. In addition, they are safer for pedestrians.
A roundabout, like a traffic circle or rotary, is a circular intersection where drivers travel counterclockwise around a center island. But unlike a traffic circle or rotary, a roundabout has no traffic signals; drivers entering it must yield to traffic already there. Traffic circles and rotaries often have traffic signals or stop signs, and drivers entering them do not have to yield to traffic already there.
More information on roundabouts can be found at the IIHS website. A Federal Highway Administration study on roundabouts is available on its website.
