The Federal Highway Administration (FHWA) defines a roundabout as a type of circular intersection with yield control of entering traffic, islands on the approaches, and appropriate roadway curvature to reduce vehicle speeds.
Modern roundabouts are different from rotaries and other traffic circles. For example, roundabouts are typically smaller than the large, high-speed rotaries still in use in some parts of the country. In addition, roundabouts are typically larger than neighborhood traffic circles used to calm traffic. Also, a modern roundabout will have traffic yield rather than stop. This allows more efficient traffic flow through the intersection.
How to you use a Roundabout?
On approaching a roundabout, decide as early as possible which exit you need to take and get into the correct lane. Reduce your speed. Bicyclists are vehicles and need to share the lane at intersections. Therefore, allow bicycles to enter the roadway from any bicycle lane. The law gives pedestrians the right-of-way in a crosswalk. Yield to pedestrians waiting to cross or crossing on the approach.
Upon reaching the roundabout yield line, yield to traffic circulating from the left. Watch out for traffic already on the roundabout, especially cyclists and motorcyclists. Do not enter a roundabout when an emergency vehicle is approaching on another leg; allow queues to clear in front of the emergency vehicle.
Within a roundabout, do not stop except to avoid a collision; you have the right-of-way over entering traffic. Always keep to the right of the central island and travel in a counterclockwise direction. Maintain a slow speed upon exiting the roundabout. Always indicate your exit using your right-turn signal. Watch for and yield to pedestrians waiting to cross, or crossing the exit leg.
Why Roundabouts? Do more to improve safety with less money.
In multiple studies across the United States it has been shown that all crash types have decreased with roundabout as compared to signalized intersections. A recent study completed by our neighboring state, Wisconsin, has shown a 9% decrease in total crashes. The more severe a crash is the greater chance of injury or even death. Because speeds are low in roundabouts, when crashes do occur the consequences rarely result in injuries, while at traffic signals where speeds are higher, the severity of crashes can be fatal.
Roundabouts move traffic safely through intersections with slower speeds, fewer conflict points and easy decision making. Studies from the Insurance Institute of Highway Safety show roundabouts provide a 90% reduction in fatal crashes, a 76% reduction in injury crashes, a 30-40% reduction in pedestrian crashes and a 10% reduction in bicycle crashes.
The answer is ROUNDABOUTS.
For further information enclosed are further resources.
Government and State Resources
U.S Department of Transportation Federal Highway Administration
Federal Highway Administration - Modern Roundabouts - A Safer Choice
Insurance Institute for Highway Safety - Roundabout Video
Wisconsin Department of Transportation - Interactive How to use a Roundabout
Michigan Department of Transportation - Video How to use a Roundabout
MythBusters Test a Four way Stop Vs. a Roundabout