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About the Project

The I-80 study area is approximately 16 miles and begins at Ridge Road to the west and ends at U.S. Route 30 to the east. The corridor encompasses three counties (Kendall, Grundy and Will), and passes through six municipalities (Minooka, Channahon, Shorewood, Rockdale, Joliet and New Lenox), and consists of a diverse mixture of land uses including agricultural, residential, commercial and industrial with rural, suburban and urban characteristics. The roadway crosses four waterways (DuPage River, Rock Run Creek, Des Plaines River, and Hickory Creek), includes eight interchanges, and handles heavy truck traffic.

The I-80 Phase I Preliminary Engineering and Environmental Studies is taking a detailed look at the current and future transportation needs of the corridor. The study includes an analysis of existing roadway and bridge deficiencies, safety and capacity issues, and future transportation needs, and includes an extensive public involvement process. Illinois Department of Transportation will continue to reach out and engage stakeholders throughout the Phase I study process through a variety of opportunities and methods intended to maximize public participation in the identification of project solutions. The proposed improvements which are the subject of this study are funded in IDOT’s current Multi-year Highway Improvement Program. 

Project overview

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Where are We Now?

The I-80 Phase I Study took a detailed look at the current and future transportation needs of the corridor. The study included an analysis of existing roadway and bridge deficiencies, safety and capacity issues, and future transportation needs, and included an extensive public involvement process. The study followed the National Environmental Policy Act (NEPA) process and involved the preparation of an Environmental Assessment (EA). NEPA is a federal law that requires federally funded projects to evaluate a range of alternatives - including doing nothing, known as “No Build” - and asses the impacts of those alternatives on the environment. It also requires agencies proposing a project to consider input from the public before making a final recommendation. 

1 80 phase 1 study title

10 4 I 80 Timeline Overview Schedule

Purpose and Need

The Purpose and Need for the project was developed as part of the study. The purpose of the project is to provide an improved transportation system along I-80 from Ridge Road to U.S. Route 30 in Kendall, Grundy, and Will Counties, Illinois. This will be accomplished by addressing the following transportation needs:

  1. Improve regional and local travel and access.
  • Improve regional traffic flow, or levels of service, on I-80.
  • Improve local traffic flow, or levels of service, in ramp merge, diverge and weave sections and at ramp intersections with cross streets.
  • Improve multi-modal connections and opportunities.

  1. Improve facility condition and design.
  • Address pavement age.
  • Address problems with the outdated design of the roadways, or geometric deficiencies.
  • Address problems with the condition or outdated design of bridges, also called bridge deficiencies.
  • Address high truck volumes.

  1. Improve safety for all users.
  • Address the high amount of rear-end and sideswipe crashes due to traffic congestion on the mainline and in merge, diverge and weave areas.


The project team has held seven project working group (PWG) meetings, three public meetings, and two community meetings to gather input on transportation needs and potential solutions in the I-80 project area. In general, the input focused on reducing congestion on I-80, lengthening ramp entrance and exit areas, repairing existing pavement and bridges, upgrading the I-80 bridge over the Des Plaines River and upgrading existing interchanges.

Based on the feedback received, the project team divided the project into three components, or categories and evaluated alternatives for each:

  • Mainline
  • Bridges
  • Interchanges

The alternatives within each category listed above are compatible with the alternatives in the other categories. Therefore, alternatives in one category can be combined with alternatives in the other categories to create one, complete improvement alternative for the I-80 project.

The preliminary alternatives in each category were presented to the Project Working Group in September 2013. In general, the project stakeholders did not offer specific comments but showed support for any improvements that address local traffic and safety problems, specifically in the interchange areas. At Center Street, many people expressed a desire for a simpler interchange design that also improves the visual appeal as motorists approach downtown Joliet from the west. The bridges over the Joliet Junction Trail were also coordinated with representatives from the Forest Preserve District of Will County, who offered comments about lighting, drainage and general design of trails that will be impacted by the project. Finally, the project team presented to the Illinois River Carriers Association on January 20, 2012. No specific comments about the Des Plaines River Bridge alternatives were offered during the meeting.

The Alternatives were presented to the environmental resource agencies through the NEPA 404 merger process and all parties gave their concurrence to the Range of Alternatives to be studied further.

After further analysis by the study team, the preferred alternative was presented to the PWG at a meeting held on June 12, 2019. This information was presented to the public at Hearings held on November 6th & 7th in Joliet.

Next Steps

The team will develop a financial plan for the design and construction of the project. A Finding of No Significant Impact, also known as a FONSI, is anticipated from FHWA. Once federal approval is received the project can move into Phase II, Contract Plan Preparation or Design. Land Acquisition and a noise wall solicitation will take place during Phase II. Construction will begin once Phase II is complete.