I-39/90 Expansion Project

Illinois state line to Madison, Dane and Rock counties

US 12/18 (Beltline) interchange

The following documents are in Adobe PDF PDF format.
(Note: Some files are large and may take longer to download depending on individual connection speeds. Users may need to zoom in to see details.)


The purpose of the I‐39/90 and US 12/18 (Beltline) Interchange project is to accommodate I‐39/90 traffic levels with a focus on safety issues that affect Interstate travel through the US 12/18 interchange and to ensure compatibility with the I‐39/90 Expansion Project, south of US 12/18 to the Illinois state line.

A unique traffic condition exists along I-39/90 northbound, resulting in higher traffic volumes on the ramp from US 12/18 (Madison Beltline) as compared to the northbound Interstate in the core of the interchange. This video briefly summarizes this unique condition and the potential impact that design options have on safety through the interchange.

Public Hearing

A public hearing was held on December 13, 2018 at the Ho-Chunk Nation Teejop Hocira (Community Recreation Center). View the Public Hearing Notice.

View the exhibits and handout from the Beltline interchange public hearing:


An EA was produced for this project. The EA evaluated the purpose and need of the overall project, and the environmental impacts of a number of alternatives developed during the study.

EA signed on November 13, 2018.

  • View the EA (17 MB) 
    • Note: this file does not include exhibits. To view exhibits, see the complete document below.
  • EA (complete) (49 MB)


FONSI signed May 2, 2019.

  • View FONSI
    Note: this file does not include exhibits.
Date Task
December 13, 2018 Public Hearing
January 11, 2019 Comment Period Ends
May 2019 Final Environmental Decision
2020 Begin construction in core of Beltline Interchange (minimal impacts to traffic anticipated).
2021 Complete construction of Beltline Interchange and 45-mile I-39/90 corridor to the Illinois state line.

For more information regarding the environmental documents, contact:

Steven Theisen Jennifer Grimes
I-39/90 Project Communications Manager I-39/90 Project Environmental Coordinator
steven.theisen@dot.wi.gov jennifer.grimes@dot.wi.gov