Mandan first roundabout, at the intersection of Collins Ave, Old Red Trail and Hwy 1806 N, was installed in the summer of 2021. This roundabout is similar in size to the roundabout just east of Bismarck on Hwy 10 (66th Ave), and designed to handle current and anticipated traffic well into the future. Navigating a roundabout is easy. Drivers should slow down, look around, and yield to traffic already in the roundabout. The North Dakota Department of Transportation (NDDOT) recently released a video on how to drive a roundabout.

The Hwy 1806 N reconstruction project installing Mandan’s first roundabout is anticipated to be functional by early October 2021. Information on the project is available at cityofmandan.com/roadprojects.  

View NDDOT's 2021 Roundabouts Informational Video


What is a roundabout? A roundabout is a circular intersection, proven to be safer and more efficient than other types of intersections.

Roundabouts have certain essential distinguishing features:

  • Counterclockwise flow – traffic enters to the right and travels counterclockwise around a center island.
  • Entry yield control - vehicles entering the roundabout yield to traffic already circulating.
  • Low speed - curvature resulting in lower vehicle speeds (15-25 mph) throughout the roundabout.

The Federal Highway Administration identified roundabouts as a proven safety countermeasure because of their ability to substantially reduce the types of crashes that result in injury or loss of life. Roundabouts are designed to improve safety for all users, including pedestrians and bicycles. 


Roundabout rules. The intersection of Old Red Trail with Collins Ave and Hwy 1806 N was previously controlled with a four-way stop, however it could be confusing during high traffic times. Some drivers may be a little hesitant to try a roundabout. According to the NDDOT’s informational video on how to drive a roundabout, national studies show intersections using roundabout are 90% safer and more efficient than conventional intersections with traffic signals or stop signs. The NDDOT defines a roundabout as “a circular intersection where drivers travel counterclockwise around a center island.”

How to use a roundabout:

  • There are no traffic signals or stop signs.
  • There is no stopping; only yielding.
  • Drivers entering the roundabout must yield to traffic inside the roundabout.
  • The only way to exit the roundabout is to make a slight right hand turn at the desired exit. 


Benefits of a roundabout. The Federal Highway Administration indicates roundabout are a proven safety countermeasure because they can substantially reduce crashes that result in serious injury or death. Roundabouts provide many benefits including:

  • Elimination of high speed crashes;
  • Improved traffic flow;
  • Increase traffic capacity;
  • Ability to accommodate vehicles and trucks of all sizes; and
  • Increased safety for all travelers.

“Transportation focused engineers are virtually unanimous in their support of roundabouts versus four-way stops,” says City Engineering and Planning Director Justin Froseth. “In many cases they support roundabouts rather than signalization as well.”

Remember, it’s not hard to navigate a roundabout: just slow down, look around and be ready to yield to traffic already traversing the roundabout.  


Large vehicles & roundabouts. Roundabouts are designed to accommodate vehicles of all sizes, including large trucks and special purpose apparatus such as a ladder truck. They are optimized for the safety and efficiency of all users. Roundabouts feature wider entry and exit lanes for efficient movement of traffic through the roundabout; mountable aprons and curbs intended for use by vehicles with a side and/or long wheelbase; and curvature and radii that allow for easy turning movements.

Large vehicles navigate the roundabout the same way a smaller vehicle does. Remember to slow down, look around and be ready to yield.  


Pedestrians, bicycles & roundabouts. Roundabouts have 50% fewer pedestrian-vehicle conflict points than comparable stop or signal-controlled intersections. Conflicts between bicycles and vehicles are reduced as well. The lower speed used in a roundabout is associated with better yielding rates, reduced vehicle stopping distance, and lower risk of collision injury or fatality.

Pedestrians crossing a street with a roundabout intersection will cross at a shorter distance of only one direction of traffic at a time since the entering and exiting flows are separated. 

View: Pedestrians & Bikes in a Roundabout


Entering/exiting a roundabout. When entering a roundabout, drivers must yield to traffic already in the roundabout. This means only stopping to give right of way to vehicles already in the roundabout. Vehicles already in the roundabout always have the right of way. To enter the roundabout, slow down, look left for traffic already in the roundabout, stop only if it’s necessary and proceed when it’s safe to do so.

Signaling before exiting a roundabout is required. Although roundabouts may take some getting used to, the Insurance Institute for Highway Safety, indicates they reduce the number of injury crashes by 72-80% at intersections where stop signs or traffic signals once were used.

A roundabout is an intersection where traffic travels around a central island in a counterclockwise direction. When approaching a roundabout remember to:

  • Travel in a counterclockwise direction. Do not stop or pass; and
  • Yield to pedestrians and bicyclists crossing the roadway.
  • Signaling before exiting is required.  



View the Federal Highway Administration's Rules of a Roundabout

View the Federal Highway Administration's Modern Roundabouts: An Innovative Solution to Intersection Safety Concerns

View the NDDOT's How to Drive a Roundabout.