The reduced delay of an roundabout intersection results in reduction in noise, air pollution and fuel consumption. This will likely 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.