MnDOT presents selected northern-roundabout design for Highway 210 at I‑94 junction

MnDOT project manager Laurie Vanderheiter presented an overview of the Trunk Highway 210 reconstruction at the Interstate 94 west junction to the Fergus Falls City Committee of the Whole. The agency selected a northern alignment with roundabouts and a single replaced bridge to simplify the transition from four lanes to two and add pedestrian access to nearby destinations.

Vanderheiter said the project scope includes bridge replacement, Americans with Disabilities Act improvements, ramp realignments, intersection control, lighting upgrades and pavement reconstruction. “The alternative that was selected was the northern roundabout option,” Vanderheiter said, adding that all options would provide pedestrian facilities across the bridge and to the Walmart/Mabel Murphy’s intersection.

MnDOT described benefits of the northern-roundabout design as a longer merge distance on the western ramp, a flatter westbound off‑ramp approach and continuous traffic flow through roundabouts. The design eliminates one of the two existing bridge structures and replaces the eastern transition with a single bridge. Roundabout geometry was sized for a design semi and a larger control vehicle; larger vehicles would use a truck apron.

Cost participation varies by element. MnDOT will pay 100% for some state legs and for bituminous trail on the north side of the project; the city will pay for standard sidewalk on the south side unless it elects to upgrade to concrete. Vanderheiter said the overall project estimate is about $17.2 million and that the city’s current share is projected at approximately $800,000–$900,000, subject to refinement after utility cost estimates and qualification for reimbursement of certain utilities located in interstate right of way.

MnDOT said it will prepare a post‑construction maintenance agreement with the city. Under the described responsibilities, MnDOT would maintain driving lanes on Trunk Highway 210, the interstate ramps, bridge inspection, culverts, select nonroutine storm sewer items, pavement markings on MnDOT roads, ramp lighting and roundabout lighting at the western ramps. The city would remain responsible for Redwood Lane and Lincoln Avenue, routine sidewalk and trail maintenance (snow removal, sweeping and minor repairs), signs and pavement markings on local streets, and lighting power and relamping for specified roundabout and bridge lighting.

Council members asked whether the posted speed limit would change; Vanderheiter said MnDOT is not planning to change the posted 45 mph limits but that roundabouts will reduce achievable operating speeds and MnDOT could perform a post‑construction speed study. Council members also asked whether the crescent-shaped area shown in the roundabout drawing would be raised curb; Vanderheiter said that area is level pavement (pavement markings) to allow a driver who realizes they do not want to take the interstate an opportunity to merge and use the roundabout.

The city asked MnDOT to provide a cost difference for upgrading the south‑side bituminous trail to concrete; Vanderheiter said upgrading to concrete would increase the city’s cost by approximately $200,000 and that she would provide the cost comparison to City Engineer Andrew and staff.

Vanderheiter said MnDOT will evaluate tree needs after the first winter of operation and could add trees in a separate project if warranted; MnDOT does not at present practice net tree mitigation across unrelated sites in the same way it handles wetland mitigation.

No formal action was taken at the Committee of the Whole; Vanderheiter left materials and staff follow‑up items were requested by the city.