This article originally appeared in The Free Press.

NORTH MANKATO — It’s official: roundabouts are coming to Highway 169 in Mankato-North Mankato in 2027, part of a two-year $70 million reconstruction and redesign of the area’s busiest north-south corridor.

The project is almost certain to force a closure of the highway and a resulting detour for at least part of the 2027 construction season, although the Minnesota Department of Transportation hopes to complete the second part of the project in 2028 while thru-traffic continues to flow.

The scope and anticipated disruption of the undertaking will make it one of the biggest construction projects to hit the two cities in decades. That was evident Monday night when the city councils and management teams of both Mankato and North Mankato gathered in a rare joint meeting to hear an update of MnDOT’s preliminary plans.

“It’s starting to take shape,” Mat Thibert, a project manager for MnDOT, told the municipal leaders gathered at North Mankato’s City Hall.

The Free Press reported a year ago the agency’s tentative plans for the project, including the timing and the intention to replace signalized intersections with roundabouts. But Monday night was the first time that MnDOT confirmed that a shutdown of Highway 169 would likely be necessary to complete the first season’s work.

“We do anticipate a detour,” Thibert said. “… We acknowledge that it’s going to be very impactful.”

Thibert emphasized that the agency will be looking to make the detour as short-lived as possible during the summer of 2027 and that a repeat was not expected when construction resumed in 2028.

The preliminary plan

The overall project will involve the reconstruction of Highway 169 from Riverfront Drive near West High School to Mankato’s northern city limits near the Happy Chef restaurant and the Kiwanis Recreation Area.

The 2027 portion — more than two miles long and stretching from Belgrade Avenue to Lake Street on Mankato’s north side — will bring the most dramatic changes.

Two sets of signal lights will be eliminated — at Webster Avenue in North Mankato and at Lind Street in Mankato. Lind Street, which is the intersection just south of the Highway 169-Highway 14 interchange, will be closed. The intersection’s close proximity to the interchange’s ramps was found to be a major cause of its high crash rates, according to a corridor study completed in 2021.

To improve safety and traffic flow, a roundabout will be constructed at the Webster-Highway 169 intersection, and a new intersection, also a roundabout, will be added at North River Lane near the Hiniker Pond area. The new intersection is about 800 feet south of the current Lind Street intersection.

The two roundabouts will provide access to businesses and other properties along the highway via frontage roads, including the existing North River Drive on the east side of Highway 169, and Range Street on the west side. A new street — Hiniker Parkway — will be constructed by the city of Mankato to provide improved access on the west side to help make up for the loss of the Lind Street intersection.

The 2028 project will focus on reconstruction of the pavement on the mile-plus segment from Belgrade Avenue to just south of the Riverfront Drive interchange. Preservation work will be done on a trio of bridges — the North Star Bridge over the Minnesota River and the bridges carrying Highway 169 over Riverfront Drive and over the connecting ramps between Highway 169 and North Mankato streets such as Center Street and Lookout Drive.

The second-year work is expected to be nearly as expensive as the first year, but the appearance of the corridor won’t be noticeably altered.

“When it’s completed, the public is not going to notice significant change,” Thibert said of year two.

Details pending

The size and complexity of the project is requiring years of planning, and final designs won’t be completed for the northern segment until April of 2026 — the following April for the southern segment.

While emphasizing that expectations could change as those designs are fine-tuned, Thibert provided tentative answers to questions from the council about a variety of topics.

That detour of Highway 169 in 2027? Most likely, thru-traffic will be diverted around the construction site via Highway 14, Highway 22 and Blue Earth County Road 90, he said, again emphasizing the intention to make the disruption as short in duration as possible.

MnDOT will work with the cities to provide alternate routes for local traffic to reach businesses and neighborhoods.

Although Thibert couldn’t guarantee that disruption in 2028 will be limited to lane restrictions rather than shutting down the highway, that is the current plan.

“The southern phase we’re hoping to do with the maintenance of mainline traffic and not have any detours,” he said.

Bikes and beauty

The two-year corridor study — a joint effort between MnDOT and local jurisdictions — strongly suggested that any highway improvements be accompanied by pedestrian upgrades, as well as aesthetic elements, and the project will attempt to accomplish both.

MnDOT is exploring the technical feasibility and projected cost of a grade-separated path for pedestrians looking to cross Highway 169, which has trails on each side. Thibert said the best option currently looks to be an underpass rather than a pedestrian bridge.

Civic leaders are also hoping to boost the appearance of the northern section of the Highway 169 corridor because it serves as a prominent entrance into the two cities.

Thibert said MnDOT will be looking to form a panel of community members later this year to work with a landscape architect and others to consider visual elements that can be added to the project. That team would likely look at ways to tie the corridor into natural features such as the river and the bluffs, maybe the silos mural, to create “a welcoming environment” that emphasizes what’s unique about Mankato-North Mankato.

Once options have been identified, they will be presented to the public for comment, probably in the spring of 2025.

In response to other questions from council members, Thibert said the speed limit along the corridor is expected to remain at 50 mph, although drivers will need to slow when approaching the roundabouts. And while he didn’t know if sound-barrier walls would be part of the project, a noise analysis will be done.