M-81 Roundabout, driver's perspective

A roundabout is a type of circular intersection that has been used in Europe for several decades. In recent years, MDOT has constructed several roundabouts on state trunklines and more are planned. (You can view an online demonstration on how to drive in a roundabout.)

Benefits of roundabouts
Modern roundabouts are superior to old-style traffic circles and to conventional intersections at many locations. They are designed to maximize traffic flow and safety in several ways:

• They keep traffic moving; this decreases emissions and improves fuel economy.
• They increase safety because there is no stopping in a roundabout and no left turns across opposing traffic lanes.
• They force vehicles to slow to a safe speed for the intersection.
• They can be landscaped to offer an attractive gateway into a city or other area.

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.

What is the difference between a roundabout and traffic circle?
In a traffic circle, drivers first come to a stop and then proceed according to the traffic. In a roundabout, drivers yield to traffic when entering the roundabout.

More roundabout information
Roundabout Safety Comes to America - Federal Highway Administration
Modern Roundabouts - New York Department of Transportation
Roundabouts USA