Blatnik Bridge between Duluth and Superior headed toward retirement, replacement

DULUTH – Ask a local for the quickest route between Duluth and Superior, Wis., and they'll probably tell you to take the high bridge. What will they say in the future? The John A. Blatnik Bridge has spanned the harbor for 60 years, but in another 10 it may be gone.

The Minnesota and Wisconsin transportation departments (MnDOT and WisDOT) will be replacing the Blatnik, or giving it a massive restoration, as it approaches the end of its intended life span.

"We are building the foundation blocks," Pat Huston, the assistant district engineer for major projects at MnDOT, said during a two-hour virtual public meeting on the project last week to update the community. But he was using a metaphor.

Construction isn't expected to begin until 2028, and plans are still taking shape. It's so early in the process that there isn't a full cost estimate yet.

"We can't estimate what we don't know we're doing," Huston said, though the agency has pegged the cost of just replacing the center span at $400 million. Minnesota and Wisconsin would split the cost of the work.

At a minimum, the next bridge would improve the structural condition, increase safety and better accommodate heavy trucks. Pedestrian and bike access, which the Blatnik currently lacks, has been identified as a "secondary" need.

The bridge carries Interstate 535 and is the second-longest in Minnesota after the Richard I. Bong Bridge — the other span connecting Duluth and Superior, which opened in 1984. The 1.5-mile Blatnik carries about 33,000 vehicles per day on average, and wear and tear has been compounding.

Inspections, typically performed every other year, are now required annually. Major work is expected every four years to keep the bridge open, with another $9 million round due in 2022. And the Blatnik hasn't been able to handle oversized trucks since 2016 — the weight limit is now 80,000 pounds — driving up fuel costs for truckers who are detoured to the Bong Bridge.

The public is being asked to weigh in with their own vision for the next bridge.

"Is having a view of the city skyline from the bridge important? Should MnDOT and WisDOT fix and rebuild within the footprint of the existing bridge, or build a new bridge adjacent to the current structure?" MnDOT said in its call for comments, which are due Tuesday.

Simply taking out the bridge and routing traffic onto the Bong is unlikely; officials pointed to the 2018 oil refinery explosion and fire in Superior as a reason it's important to have two bridges. Nearly the entire city of 26,000 was under an evacuation order at one point during the daylong blaze.

The new bridge would have a 100-year life span, officials said, and they're considering how autonomous vehicles and other technology would have to be accommodated.

The project would almost certainly change how the bridge connects to Superior. Now, interstate traffic into town is sent downhill directly onto Hammond Avenue and into a neighborhood. A stretch of Hammond, beginning at the base of the bridge, boasts the highest concentration of crashes in Superior, and the third-highest concentration in northwestern Wisconsin, according to WisDOT.

By the time construction starts, the Duluth side of the interchange will be remade. That $343 million MnDOT project is now underway and will reconfigure the tangle of interchanges known as the Can of Worms. The Twin Ports Interchange project, as it is officially known, is expected to be largely complete by the end of 2023 with more work expected before the end of the decade.

Brooks Johnson • 218-491-6496