WisDOT evaluates design alternatives to determine whether a signal, roundabout or other control is best suited for the location based on safety, efficiency and estimated cost.

Of the state’s 383 roundabouts, 220 are on the state trunk highway (STH) system and 163 are on local highways.


  • Are proven to reduce the number of severe injury crashes and deaths
  • Provide a good economic value
  • Reduce delay and improve traffic flow
  • Are a greener alternative with less vehicle idling, lower fuel emissions and less wasted fuel

Driving vehicles in a roundabout

  • Slow down.
  • Watch for and obey traffic signs.
  • Move into the correct lane the direction you want to travel as you approach the roundabout.
  • Yield to pedestrians and bicyclists as you enter and exit the roundabout.
  • Yield to all lanes of traffic on your left before entering.
  • Keep your speed low and stay in your lane within the roundabout (do not change lanes within the roundabout).
  • Exit carefully to your destination. Use your right-turn signal, in front of the splitter island just prior to your exit, to indicate your intention to exit.

Watch For Large Vehicles

Large Vehicles breakdown
Large Vehicles breakdown
  • 2015 Wisconsin Act 139 requires drivers at roundabouts to yield right-of-way to trucks and other large vehicles (and combinations of vehicles, such as trucks towing boats or RVs towing cars) measuring at least 40 feet long or 10 feet wide.