What is a Roundabout?

In a nutshell, a roundabout is a type of intersection where motorists are required to slow down, yield to vehicles on the left, drive around a central island, and exit onto their intended route. Roundabouts are used extensively throughout the world to reduce crashes, traffic delays, fuel consumption, air pollution, and construction costs.

The slower speed and circular design have dramatically reduced the #1 killer at conventional intersections: the high-speed head-on or broadside T-bone crash.

Entering the Roundabout

  • Decide which lane to be in before reaching the roundabout.
  • Drive slowly. Do not be in a hurry or pass vehicles ahead of you.
  • Enter the roundabout only after yielding to all of the cars on your left.
  • Drivers in the roundabout have the right-of-way.

Exiting the Roundabout

  • Continue counter-clockwise around the center island until you see your exit and signal to turn.
  • Keep in mind that both lanes can exit (see above diagram). As in a standard intersection, use the left lane to make left turns, U-turns, or straight ahead movements.
  • Drivers in the right lane should exit or go straight.
  • Always stop for pedestrians and bicycles waiting to use the crosswalks. They have the right-of-way.


All pedestrians must cross at the designated crosswalks. Although vehicles are required to stop for pedestrians, always exercise caution when crossing.


Bicyclists are encouraged to walk their bikes and use the pedestrian crosswalks. Only experienced bicyclists should ride within the roundabout. Where available, bicyclists are to use the 10-foot-wide sidewalks.

Emergency Vehicles

Do not get in the way of emergency vehicles. If you are within a roundabout when an emergency vehicle approaches, move through, exit, and then pull over.

Go to the DOT's website to see more information on the proper use of roundabouts.

Sun Prairie has 5 roundabouts; 3 located along West Main Street and 2 along O'Keeffe Avenue.

Roundabout Directions