A roundabout replaces a conventional intersection managed by traffic signals or stop signs with a one or more lane wide rotary around a center island median. Roundabout construction has accelerated nationwide, especially in neighborhood areas and with new developments. States such as Wisconsin converted a number of intersections to roundabouts to reduce crash rate numbers. The state also uses roundabouts routinely for interchange redesign, implementing the dumbbell and dog bone design in place of conventional diamonds.