Minnesota Department of Transportation

511 Travel Info

Roundabouts

Getting through intersections safer and faster

A roundabout in rural Minnesota
A typical roundabout on a Minnesota state highway

Since the first one was installed in 1995, roundabouts have been built across the state by MnDOT, counties and cities. As of October 2024, there were more than 530 roundabouts on all roads. They have become an increasingly popular intersection type by traffic engineers, communities and transportation officials.

Why roundabouts work

In short, roundabouts are being used because they work well. A roundabout used at the right location will let drivers get through the intersection more safely and in less time. There has been an 86 percent decrease in fatal crashes, an 83 percent decrease in life-altering injury crashes and a 42 percent overall decrease in the injury crash rate at intersections with roundabouts. They handle high levels of traffic with less delay than most stop signs or signals. They slow traffic so entering and exiting are easier and more efficient, and where roundabouts replace signals, idling decreases and reduces vehicle emissions and fuel consumption by 30 percent or more.

How roundabouts work

Due to the curvature of the roundabout entry, drivers slow and check traffic coming from the left. A raised center prevents drivers from watching other traffic and only being concerned with yielding to traffic already in the circle. This prevents the intersection from "locking up," which could happen if the traffic in the roundabout had to stop for entering traffic. Pavement markings, curves at entry points, and raised islands direct traffic into a one-way counter-clockwise flow around the center island. The radius of the roundabout and the angles of entry slow the speed of all vehicles to around 15-25 mph.

  • Slow down when approaching a roundabout. For multi-lane roundabouts, get into the appropriate lane.
  • Yield to pedestrians in the crosswalk when entering and exiting the roundabout. It’s the law.
  • Yield to vehicles already in the roundabout. Merge into the traffic flow when it is safe.
  • Continue through the roundabout until you reach your exit. Do not stop or pass in a roundabout.
  • Exit the roundabout immediately if an emergency vehicle approaches and then pull over. Do not stop in the roundabout.
  • Give large trucks extra space in a roundabout. Large trucks may straddle both lanes while driving through a multi-lane roundabout or use the truck apron on the center island if needed.

  • Cross only at crosswalks and always stay on the designated walkways.
  • Never cross to the central island.
  • Cross the roundabout one approach at a time. Use the median island as a halfway point where you can check for approaching traffic.

  • Ride with traffic inside the roundabout or use the crosswalks appropriately.
  • Follow the same rules as vehicles when riding with traffic and yield when entering the roundabout. Since traffic is slower inside the roundabout, cyclists should be able to travel at or near the same speed as motorists, staying in line with the circulating traffic.

Benefits of roundabouts

Roundabouts in Minnesota have more than an 80% reduction in fatal and serious injury crashes. In 2017, MnDOT published a report studying roundabouts throughout the state since installation in the 1990s.
Highlights include:

  • An 86% reduction in the fatal crash rate at intersections where roundabouts have been installed. This includes all roundabout types (single lane, unbalanced and full dual lane roundabouts).
  • An 83% reduction in the serious injury crash rate at roundabout intersections.
  • A 69% reduction in the right-angle crash rate at intersections with single lane roundabouts.
  • An 83% reduction in the left turning crash rate at intersections with single lane roundabouts.
  • A 61% reduction in the injury crash rate at intersections with single lane roundabouts.
  • A 42% overall reduction in the injury crash rate at intersections with all types of roundabouts.

Roundabout resources