A roundabout is a circular intersection that eliminates some of the conflict traffic, such as left turns, that causes crashes at traditional intersections. Traffic maneuvers around the circle in a counterclockwise direction, and then turns right onto the desired street. All traffic yields to motorists in the roundabout and left-turn movements are eliminated. When properly designed, roundabouts offer a safer alternative to the traditional intersection, resulting in fewer serious vehicle crashes.

Additional research is currently underway to explore the safety implications of roundabouts for pedestrians and bicyclists. Observations of how pedestrians and bicyclists interact with motorists at roundabouts found that there were not substantial safety problems. However, some risky behavior is observed in the following areas:


  • Exit legs: motorists exiting from the roundabout were less likely to yield to crossing pedestrians than on entry legs
  • Two-lane roundabouts: approaches with two lanes were related to higher rates of hesitation for crossing pedestrians and lower rates of yielding from motorists


  • Circulating on edge of lane: there was a greater chance of conflict with motorists for bicyclists who rode on the edge of the lane while circulating in the roundabout, rather than taking the lane
  • Wrong-way riding: bicyclists who approached the roundabout on the wrong (left) side of the street had a greater risk of conflicting with exiting motorists