Travelers and residents faced with the ongoing Interstate 35 reconstruction through Lincoln Park in Duluth are being asked to raise their alert levels some more come Monday.
That’s when the $343 million Twin Ports Interchange reconstruction project both reaches significant milestones while also throwing drivers a curveball.
Southbound travelers on I-35 will be diverted onto a new two-lane bypass, using Lower Michigan Street. It's an alignment that will be in place for the next year.
“We’ll have a 40 mph speed limit down here, which will allow people time to process,” Pete Marthaler said earlier this week during a tour of the site. “This is a substantial change, so we want people to go slow to where it gives them time to make a decision.”
Marthaler is the Minnesota Department of Transportation's major projects manager in charge of reconstruction.
He described how the temporary southbound lanes of I-35 will serve as a 3,700-foot chute through the project, slightly more than two-thirds of a mile. The move to the new I-35 bypass comes with the closing of southbound access to the Blatnik Bridge, also ending Monday.
“After you get past Mesaba (Avenue), you’ll have two lanes coming right through here,” Marthaler said, standing in the middle of the new 5-inch asphalt surface of the bypass. “There are no options to come off. If you want to go to Wisconsin, you have to go take the Bong Bridge” — the official detour located farther south off I-35.
The Lower Michigan Street bypass is part one of two when it comes to flopping traffic in the middle of the four-year project designed for completion in spring 2024.
In two weeks, the northbound lanes of I-35 through Lincoln Park will also be closed as the project work moves closer to the bayside. Those lanes have been carrying single lanes in each direction for much of the past year. Instead, two lanes of northbound traffic will be shifted over onto what are normally the southbound lanes of I-35.
That means, for the next year, four lanes of I-35 traffic will be coursing through Lincoln Park side by side. At one point, Marthaler pointed out where the four lanes will jog together just beyond 21st Avenue West and over a temporary and newly built stretch of road extending from the bypass onto southbound I-35 proper.
“We couldn’t have one lane in each direction in the winter, that’s not a safe or viable outcome,” Marthaler said. “The most important part is we’re moving to two lanes in each direction.”
The idea to use Lower Michigan Street as a section of I-35 shaved almost a full year off of the length of the project, Marthaler said.
“Actually, it was an idea proposed by the contractor, as part of their interview process when we selected them,” Marthaler said of the joint venture between Ames Construction, of Burnsville, Minnesota, and Kraemer North America, of Plain, Wisconsin.
When the northbound lanes of I-35 close in two weeks, it'll usher in key new phases of construction.
For one, the remaining 305-foot gap between the new outlet and inlet box culvert ends of the combined Mission and Coffee creeks will be accessible and constructed.
“That’s going to be our winter work,” Marthaler said, reminding that Coffee Creek needed to be diverted to clear the way for hundreds of ground improvement columns that will be installed next spring as crews rebuild bridges and much of I-35 at ground level.
Moving Coffee Creek is why West Superior Street is currently closed for at least two more weeks, while traffic is detoured in the Lincoln Park neighborhood.
“Work that’s happening on Superior Street is due to Coffee Creek relocation,” Marthaler said. “We couldn’t guarantee the long-term viability of rebuilding those bridges over top of a 100-year-old stone arch (underground creek), so we relocated Coffee Creek out into 22nd Avenue West.”
The new creek will feature an open channel through the neighborhood, the project’s most stunning feature to date.
Having northbound lanes of I-35 closed will also give contractors more space to advance into new work. They’ll begin further structural demolition of several flyover spurs to Interstate 535 to Wisconsin and U.S. Highway 53 toward the mall. Many of these bridges and connections have been closed for weeks and months, partially demolished and go-nowhere bridges set for replacement.
Constant traffic flow on the lower part of the interstate has prevented much of the demolition that’s needed to happen.
“We’re able to get to our structural demolition this winter, and we couldn’t really get to that until we created space down there,” Marthaler said.
The northbound exits onto the Blatnik Bridge are ending in two weeks, too, meaning travelers will need to remember to take the Bong Bridge, or they’ll sail right into downtown Duluth. Marthaler said contractors would be busy this weekend changing out road signs to be ready for Monday.
The News Tribune asked Marthaler if he'd ever seen a traffic configuration such as the one about to unfold in Duluth.
"In the (Twin) Cities, you see it," he said. "They’re always flopping traffic like this."