Nonprofit, independent journalism. Supported by readers.


Fixes to Duluth’s ‘can of worms’ highway interchange are underway, but finishing the whole project may hinge on federal infrastructure negotiations

Rife with blind merges and left exits, the section of I-35 that passes through Duluth has been in need of major changes for decades.

A rendering of Northbound I-35 with Highway 53 above.
A rendering of northbound I-35 with Highway 53 above.
Minnesota Department of Transportation

Whether you call it a “can of worms” or “spaghetti junction,” the Twin Ports Interchange in Duluth is on its way to becoming a little less tangled.

In Duluth, the 1,569-mile long Interstate 35 comes to its northern endpoint, an unceremonious four-way intersection, but not before it bisects Duluth’s downtown in a jumble of off-ramps and left-exits that make up the Twin Ports Interchange.

The intersection where I-35 and U.S. 53 merge in Duluth was built in the 1960s and ’70s, and serves an average of 80,000 vehicles daily, 5,320 of which are heavy commercial traffic like trucks and buses. The interchange is also a critical access point for the port of Duluth, one of the Great Lakes’ major ports.

But the TPI has been a difficult traffic situation for years. With a combination of blind merges and left exits weaving together on a confusing mix of “spaghetti strand” elevated roads, the interchange is a jumbled safety hazard.

Article continues after advertisement

“This is a high priority community project and… is supported by many,” said Rep. Pete Stauber, who represents the Eighth District in northern Minnesota. “We know that a lot of commerce runs through there, and it’s dangerous. There’s a lot of crashes on there, so the investment needs to be made.”

In 2018, the interchange received $20 million in federal funds for the project designed by the Minnesota Department of Transportation that will update the decades-old infrastructure.

Minnesota Department of Transportation
Although the main construction project is funded until its scheduled completion in 2024, MnDOT hasn’t yet allocated the funds to complete two other related projects, the Highway 53 bridge and the I-535 Garfield Avenue / Blatnik Bridge project over the St. Louis Bay. Funding for those projects could hinge on the outcome of the federal infrastructure package currently under negotiation in Washington.

Opening the can of worms

While out in the field Wednesday afternoon, TPI Project Supervisor Pat Huston said that the project, which started last fall, is really ramping up now.

“We’ve got basically three full construction seasons, all in 2021, ’22 and ’23,” Huston said. “Everything should be what we call ‘substantially complete’ the fall of ’23 and that means all the traffic movements in the interchange are back open. But we need to come back in ’24 to take care of final striping, final signing, things like that.”

Anyone who has lived in Minnesota for at least a full year knows the common refrain: Minnesota has two seasons, winter and road construction. Although Huston generally agrees, he said his team will work on this project all winter — yes, even in the freezing Duluth weather — in order to complete everything on time.

Like Stauber, who grew up in Duluth hearing about the “can of worms” and its safety issues, Huston said the interchange became part of local lore as he grew up in the Duluth area.

“As I lead and learn more about it, I think back to when it was built. It was a different time. There was more railroad, more industry and a lot more obstacles, and that’s why it is the way it is. It’s kind of fun, we’ve done a lot of outreach on this project, too.”

Article continues after advertisement

According to MnDOT, there are three main reasons for redoing the interchange: supporting oversize overweight equipment, especially loads that are going towards the port, replacing aging infrastructure and improving safety features.

“There was a left exit going northbound if you wanted to go up the hill to the mall, and that’s counterintuitive to how we drive. Most exits are on the right hand side, so that will be a right exit now,” said Pippi Mayfield, public engagement and communications director for MnDOT’s District 1, which includes Duluth. She also said eliminating blind merges will help with the current safety issues on the interchange.

The end goal of the project, according to MnDOT, is overall improving driver safety and eliminating confusion by creating an updated design, relocating all exits and entrances to the right side of the roadway, eliminating weaving and merging issues near the interchange and creating more lane continuity for I-35 through traffic.

Funding options for TPI’s future

With two major aspects of the TPI still in need of funding, MnDOT may need to look for federal funds. A lot might hinge on the passage of President Joe Biden’s infrastructure package. After state taxes, the second largest source of revenue for the Minnesota Department of Transportation is federal assistance. And MnDOT needs more funding if it hopes to finish up the projects that will complete the TPI renovation.

“The two projects, the 53 and the Garfield, they are in our CHIP,” Mayfield said. The CHIP, or Capital Highway Investment Plan, outlines the projects MnDOT hopes to tackle in the next 10 years.

The infrastructure package is still undergoing negotiations in the Senate. This comes after Biden closed infrastructure talks with Republicans last week, ending a weekslong effort to reach a deal, cutting off negotiations that had failed to persuade Republicans to accept his bid to pour $1.9 trillion into the country’s ageing infrastructure and safety net programs.

Older bridges being torn down on the Twin Ports Interchange project.
Minnesota Department of Transportation
Older bridges being torn down on the Twin Ports Interchange project.
Another bill might hold some hope for federal highway funding. The House Transportation and Infrastructure Committee advanced the $537 billion “INVEST in America Act,” a highway bill aiming to improve roads and transit projects across the country. However, the bill passed out of committee along party lines, with only two Republicans in the committee supporting it.

The full House is expected to vote on the bill the week of June 28.

Article continues after advertisement

Stauber, who serves on the House Committee on Transportation & Infrastructure and its Subcommittee on Highways and transit, did not vote in favor of the INVEST in America Act. Stauber did not mention specific funding plans to complete the “can of worms” improvements, but rather said that a lot of funding is riding on Biden’s infrastructure plan.

“The infrastructure package is incomplete and we’re still in negotiations,” Stauber said. “And we want to invest in those traditional infrastructure packages which are roads, bridges, airports, locks, dams and broadband.”