Bridges marked to come down as interchange work kicks up this week in Duluth

The moment Northlanders have been waiting for — maybe even dreading a little — arrives in waves starting later this week.

Over the next two weeks, the $343 million Twin Ports Interchange reconstruction project through Lincoln Park delivers major ramp and bridge closures, and new limits on Interstate 35 between 21st and 27th avenues west.

“This is the kickoff that starts affecting everything else,” Minnesota Department of Transportation major projects construction manager Pete Marthaler said last week. “Stuff up until now, we had space and time to do without affecting major traffic; but now that we’re where we’re at, we have to start impacting traffic in order to move ahead.”

Seven ramps are marked for demolition in 2021, and the first ones will come down in April.

Changes come fast starting Tuesday with the first ramp closure: the northbound I-35 exit onto U.S. Highway 53 toward the Miller Hill Mall.

That left-hand exit is one of the bugs the Twin Ports Interchange reconstruction project is designed to iron out. The new interchange configuration will feature only right-hand exits, and none of the neck-craning, blind merges which are nearing their extinction.

Another ramp closes Thursday, when the southbound Highway 53 ramp onto southbound I-35 and its pronounced blind merge closes for imminent demolition. The replacements for those bridges won’t come back online until fall 2023.

Marthaler assured the News Tribune that detours will be readily apparent throughout the city and neighborhood.

“There will be signed detours for every closure,” Marthaler said.

At 8 p.m. Friday, an overnight closure of the tunnels on southbound I-35 through eastern and downtown Duluth is being used to install a temporary sign for the duration of the project. It will inform southbound traffic of construction looming ahead, and is aimed at preventing slowed traffic from being rear-ended. At the other entry into the project, Thompson Hill already features signage aimed at alerting travelers.

The reconstruction project has already lived a long life in planning, and even through a one-year construction delay during the pandemic.

Expected to have final touches last until 2024, major construction should be complete near the end of 2023.

The project is designed to improve safety and freight movement, as well as replace aging, weight-restricted bridge infrastructure.

One of the project’s small marvels is that I-35 will only be reduced to single-lane traffic in both directions for one construction season.

But it’s this season.

And it’s happening in the coming days.

Starting Monday, crews will begin to configure northbound I-35 into one lane on the outside. A week later, by April 5, a single southbound lane of I-35 will be configured head-to-head with the northbound lane, separated by concrete barriers.

“Concrete barrier walls will make it safer,” Marthaler said, versus using cones to separate opposing traffic.

Ultimately, southbound traffic from downtown will have three choices — exit lanes for U.S. Interstate 535 to Superior, Highway 53 to the mall, or continued travel south on I-35.

“You’ll need to make a decision whether you want to go to Wisconsin, or up the hill, or shift over to the other lane and keep going south,” Marthaler said.

The interstate’s lanes heading south will be abandoned for the summer, opening up space for the project to grow. For instance, excavation will begin soon for the merging of Coffee and Miller creeks , near WLSSD.

On April 5, westbound I-535, coming over the Blatnik Bridge into Duluth, will have its exit onto southbound I-35 closed. It's another bridge scheduled for demolition.

“You’ll still be able to go north on I-35 coming from the Blatnik,” Marthaler said.

On April 12, Lower Michigan Street will close, and so will the intersection of 21st Avenue West and First Street for utility work related to the interchange project.

Lower Michigan Street will stay closed until fall, when it reopens as the two-lane southbound I-35 bypass. What are now the southbound lanes of I-35 will reopen in fall as twin northbound lanes, making for four lanes of interstate driving through the heart of the project.

Until then, the coming single lanes of I-35 will travel under a new 27th Avenue West Bridge, one of the first near successes of the project.

Over the weekend, more of the bridge deck girders were installed. Continued good weather could mean a concrete deck being poured sooner than anticipated. The bridge is on pace to open later this spring.

A joint venture between Ames Construction, of Burnsville, Minnesota, and Kraemer North America, of Wisconsin, is constructing the interchange project — one that's ready to swing into action.

“As far as things really affecting people’s traffic habits and traffic patterns," Marthaler said, "day by day there’s a calendar of things happening over the next two-and-a-half weeks."

MnDOT is conducting its monthly virtual public meeting to update interchange work at 12:15 p.m., Monday. To join the virtual meeting visit: dot.state.mn.us/d1/projects/twin-ports-interchange/meetings.html .

This story was updated at 8:11 p.m. July 6 to correct the name and location of contractor Kraemer North America, based in Wisconsin. It was originally posted at 2:55 p.m. March 28.