Minnesota Department of Transportation

511 Travel Info

I-535 Blatnik Bridge

Duluth, Minn. and Superior, Wis.

About this project

A rendering of the Blatnik Bridge location.

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MnDOT is working toward a future project to address concerns about the John A. Blatnik Bridge, one of two bridges that connects Duluth, Minn., to Superior, Wis. Carrying I-535 over the St. Louis Bay, the Blatnik is an important freight and commercial connection between the Twin Ports.

Jointly owned and managed by MnDOT and WisDOT, it is Minnesota’s second longest bridge and serves an average of 33,021 cars traveling between the two cities each day. MnDOT will lead the project, which will address aging infrastructure, improve safety and better accommodate oversize/overweight loads.

Read more information on the bridge.

Read more information on why Duluth has two bridges.

Project purpose

  • Significant deterioration in truss elements
  • Safety inspection is required every year, which requires lane closures for one to three weeks
  • Additional maintenance causes lane closures up to three times annually
  • Significant steel and cable repairs were required in 2016 after inspection revealed increased deterioration
  • Reactionary structural repair needed every four years
  • In June 2019, main truss span and approach spans were load posted for 40 tons and therefore can no longer accommodate overweight loads
  • Increased road user delays for scheduled bridge maintenance activities and inspections

Community survey

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Purpose and Need Statement

The purpose and need statement is part of environmental documentation, focuses on the problems and not the solutions for the project, and is used as a guide to evaluate and select alternatives. You can also view a one-page summary of the purpose and need statement. The evaluation criteria for the purpose and need statement can also be viewed. Read a summary for how comments were addressed on the purpose and need and evaluation criteria documents.

The alignment screening tech memo is a 41-page document that talks about the screening process for conceptual designs of the bridge, evaluation criteria, stages of the process and much more. Read a summary of the public feedback received and how comments were considered during this round of engagement (April-May 2021).