A modern roundabout is a circular, unsignalized intersection where entering traffic yields to motorists circulating counterclockwise around a central island. Modern roundabouts are engineered to maximize safety and reduce overall delay at an intersection.

• Safety - Roundabouts have been shown to reduce fatal and injury accidents as much as 76% in the United States.  Slower speed and the reduced number of conflict numbers is attributed to the reduction in accidents.

• Calming Effects - Roundabouts can serve to decrease aggressive driving, the roundabouts provide no red light to try to "beat,"  or opportunity to race away from the stop line after the signal finally turns green.

• Low Maintenance - Eliminated maintenance costs associated with traffic signals.

• Reduced Delay - By yielding at the entry rather than stopping and waiting for a green light, delay is  significantly reduced.

• Capacity - Intersections with a high volume of left turns are better handled by a roundabout than a multi-phased traffic signal.

• Aesthetic - A reduction in delay corresponds to a decrease in fuel consumption and air pollution.  In addition, the central island provides an opportunity to provide landscaping.

The lane design and pavement markings in a roundabout guide drivers safely through the intersection. States that have constructed roundabouts have documented measurable decreases in delay and congestion.