Work beginning this week along Interstate 35 through the Lincoln Park neighborhood of Duluth will give travelers a taste of what's to come in earnest next spring.
Starting Monday, contractors will begin preparations for the $343 million Twin Ports Interchange reconstruction project by installing a series of crossover lanes through the I-35 median — one each north and south of the 27th Avenue West overpass, and a third one north of the Garfield Avenue overpass.
"The work we’re doing focuses on building the crossovers, so that we are ready for spring construction in April," Pete Marthaler, a construction manager with the Minnesota Department of Transportation's Duluth office, said.
Work early in the week will close off single lanes both north and south on Interstate 35 between the 27th Avenue West and Garfield Avenue overpasses. The single-lane closures will lift after about a month — instead of prolonged lane closures throughout the winter as MnDOT once expected.
"We said we'd have one lane in each direction through the winter, but since then we've changed our minds on that," Marthaler said. "It'll probably be for a couple weeks to a month. The contractor thinks they'll be able to open it up, and we won't have permanent lane closures."
Ames Construction, of Burnsville, Minnesota, and Kraemer Construction, of Duluth, are the primary contractors on a project expected to run until at least 2023.
The crossovers will be used beginning next April to shift traffic as necessary.
Once the crossover lanes are installed, contractors will turn their attention to the 27th Avenue West overpass. The bridge was constructed in 1966 and last rehabilitated in 1984. It's being replaced as part of the interchange project.
Project manager Pat Huston said MnDOT looked at how the bridge fit into the overall interchange project and determined that replacement now was the right thing to do in terms of economics and staging.
"If we did not replace it with this project, we'd have to go out again later and impact traffic both on 27th (Avenue) and I-35," Huston said. "With the replacement now, we will be 'one-and-done' in the project area."
The design life of new bridges similar to the 27th Avenue overpass is now 75 years, Huston added.
After the crossovers are complete, contractors will stabilize the ramps around 27th Avenue West and then begin excavating for the future bridge abutments. During excavation and demolition, temporary single-lane closures will occur to accommodate work on the project.
The ramps at 27th Avenue West will remain open, but the bridge will not be open to cross traffic.
Doing work now allows all parties to get acquainted with a project that will dominate I-35 through Lincoln Park for at least the next three years.
"We'll get the wrinkles ironed out on our working relationships before we hit major stuff in March, April and May," Marthaler said.
The Twin Ports Interchange reconstruction project is designed to make the roadway safer by eliminating left-hand exits and blind merges, while also replacing old bridge infrastructure throughout the project in order to better accommodate freight traffic.
Among the work starting next spring will be the actual reconstruction of the 27th Avenue overpass along with the installation of a four-barrel box culvert routing Miller and Coffee creeks into the St. Louis River.
Reconstruction work on the overpass is expected to be completed in June 2021. The primary detour for users of the 27th Avenue overpass will be 40th Avenue West.
By late spring 2021, I-35 will be reduced to a single lane in each direction between 27th Avenue West and Garfield Avenue until fall.
By late fall 2021, southbound I-35 traffic will be moved to Lower Michigan Street in two lanes between Garfield Avenue and 22nd Avenue West, and northbound I-35 will be diverted to the existing southbound lanes of I-35.
Two lanes of traffic in each direction will be maintained until fall 2022, when another configuration will be required.
For more on the project, visit MnDOT's project link.