Why Install Roundabouts?
Roundabouts are the safest type of at-grade intersection. They create slower speeds, fewer conflict points for pedestrians and motorists, and reduced collision angles compared to STOP sign or traffic signal control. For more information, refer to Safety.
Since motorists do not always have to stop, delays and queues are usually less compared to STOP sign or traffic signal control especially at high traffic flows. For more information on their performance under heavy flows, refer to Avon and Vail.
With reduced delay, roundabouts lessen noise, air pollution and fuel consumption. This is likely to become an increasingly important consideration in the future. Roundabouts also provide opportunities for traffic calming and speed transition, as well as landscaping and gateway treatments.
When societal costs associated with crash incidence are accounted for, roundabouts are often less expensive than other intersection control alternatives. A high-capacity roundabout can reduce the need to widen adjacent roads, a significant consideration with nearby underpasses or overpasses. Increased safety means lower emergency response, health care and other societal costs. Roundabouts do not specifically require periodic maintenance like traffic signals, and there is no need to be concerned with power outages.
Roundabouts offer a more bicycle friendly experience than traditional intersections.