Montana Department of Transportation

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Active Project - Sidney Roundabout

Sidney Roundabout

Sidney Roundabout logo

Project Overview

MDT is committed to bringing the most up-to-date safety features to our roadways. In support of these efforts, MDT will be continuing construction of a roundabout located at the intersection of MT-16, MT-200, and MT-23, approximately one mile south of Sidney.

Sidney Roundabout Scene
Sidney Roundabout Scene
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Project Timeline and Cost

The project was started in July of 2017 and is expected to be complete in the summer of 2018. The total cost for this project is $4.4M, which includes the new roundabout and roadway revisions to the four legs approaching the intersection.

Impacts to the Public

Because this is a construction project, the public is asked to prepare for minor delays when traveling through the area. The public may currently expect detours and reduced speeds until construction of the roundabout is complete.

Members of the public should plan for increased travel times and can find up-to-the-minute detour and delay information at MDT Travel Conditions (under JCT of MT 16, MT 23, and MT 200).

Simple. Successful. Safe.

Through careful planning, roundabouts are designed to substantially reduce the types of crashes which result in serious injuries or fatalities. Roundabouts constructed at intersections along high-speed, two-lane rural highways reduce crashes by 68% and reduce serious injury crashes by up to 88%.

Roundabouts also improve traffic flow and reduce the amount of time you have to wait to go through the intersection. Instead of coming to a complete stop, as you would at a signal or sign, traffic slows, you yield to traffic in the circle to left, then enter the roundabout. Roundabouts are also easy for pedestrians to navigate, as they only have to cross one direction of traffic at a time.

One roundabout in Montana reduced crashes by 70% and eliminated fatalities over a five-year period.

Made with You in Mind

Roundabouts are constructed with large trucks, RVs, equipment, and horse trailers in mind. The interior section of the roundabout containing colored and patterned concrete is called a truck apron and these larger vehicles are encouraged to use the truck apron to be able to safely drive through the roundabout.

Large Loads

  • Designed to accommodate the turning movements of large trucks.
  • Roundabout design and size influenced by truck turning paths.

Multi-lane Design

  • Large trucks can use both lanes if needed.
  • Provides additional space for large loads.

Mountable Truck Apron

  • Trucks can track onto mountable apron.
  • Designed with flat slope and low height to accommodate low clearance vehicles.
  • Sufficient width for trailer turning paths.