A roundabout is a one-way, circular intersection in which traffic flows around a center island. Roundabouts are designed to meet the needs of all road users--drivers, pedestrians, pedestrians with disabilities, and bicyclists. A roundabout eliminates some of the conflicting traffic, such as left turns, which cause crashes at traditional intersections. Because roundabout traffic enters or exits only through right turns, the occurrence of severe crashes is substantially reduced. Small-angle collisions that may occur as a result of a right-hand turn are typically less severe than other types of collisions. The three safety design features of a roundabout are yield control of entering traffic; channelized approaches that deflect traffic into the proper one-way, counterclockwise flow; and geometric curvature of the circular road and angles of entry to slow the speed of vehicles. These three features are critical to the success of a roundabout because they effectively decrease driving speed to typically 48 kilometers (30 miles) per houror less.