Pedestrian and Bicyclist Safety
Roundabouts have significantly lower design and operating speeds. These attributes have been linked through various research efforts to an increased willingness of drivers to yield to pedestrians. With lower speeds and more driver awareness, roundabouts are associated with a lower risk of injury or death in the event of a collision.
When a roundabout is designed properly, the driver-pedestrian interaction at the crosswalk is separated with the vehicle-vehicle interaction at the entry yield point or the exit from the circle.
Despite what you may think, many of the risks associated with signalized intersections do not exist at roundabouts. For example, the risk for pedestrian-driver conflicts are VERY great at signalized intersections, including permissive left turns, right-turn-on-red, and channelized (high speed) right turn lanes.
The pedestrian crossing distance at roundabouts is a fraction of that at a signalized intersection, and pedestrians only have to look at one direction of travel at a time. As such, the pedestrian decision-making should be greatly facilitated.
Another nice aspect of roundabouts is that they give the bicyclists a few options when it comes to navigating around one. Many states have very good experience with bicyclists at roundabouts, giving them the choice between using the sidewalk (novice cyclists) or claiming the travel lane (advanced and commuters).
Bastian J. Schroeder, Ph.D., Assistant Director, Highway Systems, Institute for Transportation Research & Education (ITRE), North Carolina State University