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Roundabouts

US-131/M-86 roundabout at Fife Lake in MDOT's North Region.
Department of Transportation

Roundabouts

What is a roundabout?

A roundabout is a modern circular intersection design increasingly used by MDOT. Roundabouts differ from traffic circles; they are smaller and require drivers to yield to vehicles already circulating. 

Roundabouts have been proven to reduce traffic delays and overall congestion. When properly selected and designed, they can accommodate high traffic volumes, including commercial trucks and large emergency vehicles.

Roundabouts slow vehicles and reduce conflict points, lowering the risk of serious and fatal crashes, especially head‑on, left‑turn and angle collisions.

Yield signs minimize unnecessary stopping and idling, which reduces emissions, decreases delays and increases intersection capacity.

Roundabouts remove the long‑term operational and maintenance costs associated with powering and servicing traffic signals.

Roundabouts create opportunities for landscaping and green space without visual clutter from poles or wires.

Driving safely through a roundabout Video

Driving safely through a roundabout

Roundabouts are easy to navigate and safer than traditional intersections.

  • Choose your lane before entering the roundabout.
  • Yield to traffic already circulating in the roundabout.
  • Yield to pedestrians in marked crosswalks.
  • Signal your exit with your turn signal.
  • Follow posted signs and pavement markings for direction.

 Traffic inside the roundabout always moves counterclockwise.

Additional roundabout videos
An MDOT roundabout showing the vegetation in the middle.

Safety and operational benefits

Many roundabouts include vegetation or landscaping in the center for both aesthetic and practical reasons. Low‑maintenance designs reduce safety risks and long‑term costs by minimizing the need for frequent upkeep. 

  • Center landscaping blocks the glare of oncoming headlights.
  • A raised, landscaped center signals drivers to slow down and reinforces that traffic cannot travel straight through the intersection.
  • Vegetation or barriers help direct drivers’ attention to the right and left where vehicle and pedestrian movements matter.
  • Landscaping discourages pedestrians from crossing through the center of the roundabout.