John A. Blatnik Bridge Replacement

The John A. Blatnik Bridge is worn out, and replacing it is now the largest public-works job in the Twin Ports. The $1.4 billion design-build project will build a new structure carrying Interstate 535 and US 53 over St. Louis Bay between Duluth, Minnesota and Superior, Wisconsin, the main freight and commuter link between the two cities.

Project Scope

The Minnesota and Wisconsin transportation departments picked Ames-Kraemer Joint Venture II to design and build the replacement, with Parsons providing design and construction oversight after handling preliminary engineering. The two states each committed $400 million toward the work, with federal bridge dollars covering the rest. Construction is slated to start in late 2026 and run through 2031. Keeping traffic and shipping moving during a multi-year build over a working bay is a big part of what the design-build team has to solve.

Why It Matters

The Blatnik carries tens of thousands of vehicles a day and ties the ports, rail, and highway freight of the western Lake Superior region together. Its condition had forced load restrictions that pushed heavy trucks onto longer detours, a daily tax on regional shippers. A new bridge lifts those limits and locks in the crossing for another 75 years. For MnDOT and WisDOT, delivering a project this size across a state line, on a design-build basis, is a coordination test as much as a construction one.

Project Team & Details