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M-21 Rebuilding/Roundabout Project FAQs

  • What is the timeline projection for the roundabout construction project?

    The project is scheduled to be let (bids received) in December 2028, with construction taking place approximately from April to November 2029.

  • How will pedestrians cross through the roundabout?

    MDOT is currently working on designing the roundabout, including the pedestrian crossings. The crossings will connect with the existing shared-use path along Scott Road. MDOT will continue to work with the City of St. Johns on this design.

  • Why is MDOT putting a roundabout at the M-21/Scott Road intersection?

    In the late 2010s, MDOT and the City of St. Johns had multiple discussions about the M-21/Scott Road intersection. There were concerns with speeding and visibility issues due to the geometry of the intersection. In 2021, the City of St. Johns voted to send a resolution of support to MDOT for a roundabout to be built at the intersection.

    With the support of the city, MDOT completed a scoping report for a rebuilding project along M-21, including the construction of a roundabout. Additional funding for a roundabout was secured in 2024 due to operational and safety concerns at the intersection.

    In late 2025, both the City of St. Johns and Bingham Township passed a resolution requesting MDOT to reconsider the proposed roundabout, to install a traffic signal, and to conduct a traffic study to extend the traffic control further east on M-21. MDOT has completed a comprehensive traffic study to evaluate the M-21/Scott Road intersection for signalization. This study determined that a signal would not be appropriate at this location. MDOT is continuing to evaluate measures that could be implemented to encourage reduced speeds.

    A roundabout at this intersection will improve safety and traffic flow. It will also serve as a clear gateway to St. Johns' historic downtown.

  • Why not add a traffic signal at the existing M-21/Scott Road intersection?

    This location was studied for a traffic signal, which found that a traffic signal would not be justified at this location due to low traffic volumes.

  • Will there be posted signs for reduced speed as you come up to the roundabout?

    Yes, advisory speed signs will be posted below the advance roundabout signs. Additionally, the geometry of the approach legs will require vehicles to slow down as they maneuver to and through the roundabout.

  • Will any businesses be closed due to the roundabout?

    No businesses will be closed due to this project. Access to nearby businesses will be maintained throughout construction.

  • How will this roundabout impact semi-trucks?

    The roundabout will be designed to accommodate semi-trucks. In addition to the circulating lanes, there will be a truck apron in the center island designed for interstate semi-trucks and trailers. The curb that runs along the inside of the roundabout island is a shorter-height mountable curb, which allows the rear tires of the truck's trailer to traverse onto the truck apron smoothly to minimize load shifts.

  • How will the roundabout impact traffic flow on Scott Road?

    Scott Road will experience both improved northbound and southbound traffic flow.

  • Will there be public education on how to use the roundabout?

    MDOT will provide to the township and county website links and YouTube videos for general information about roundabouts. MDOT has created a project website that will also have these links posted for the public to view. MDOT also plans to hold an open house to inform the public about the project.

  • Will there be crossing lights for pedestrians to cross the roundabout?

    No, traffic signals for pedestrian movements are not currently planned as part of this project. The department typically places enhancements for pedestrian crossings, such as laddered pavement markings with pedestrian yield signs to highlight where pedestrians are crossing.

  • Will there be enough time for pedestrians to cross through the roundabout?

    Yes, the splitter island of the approaches offers an area of refuge so that a pedestrian only needs to cross one direction of traffic at a time. Motorized traffic will be required to yield to pedestrians after they enter the crosswalk.