I-70 Traffic Flow Improvements Project

T.R. Hughes Blvd. to Woodlawn Ave.,
including the Highway K/Main Street interchange

Have you experienced congested intersections and delays on I-70 through O’Fallon? This project is working to improve the interchange at I-70 and Highway K/Main Street, relieve congestion on Highway K near I-70, help traffic flow better from T.R. Hughes Blvd through Woodlawn Avenue, and make travel safer and more efficient and improve air quality.

Over the past 10 years, traffic along the I-70 and Highway K/Main Street corridors in O’Fallon has been increasing at a dramatic rate. If this is not addressed, growth will have a significant impact on O’Fallon’s quality of life. The interchange at I-70 and Highway K/Main Street has become an even greater challenge, with the number of traffic signals causing significant backups during most of the day.

Phase 1 of this project will focus on the area from T.R. Hughes to Main/Hwy. K, which is the largest portion of the project. Phase 2 will focus on the area west of K to Woodlawn. Both phases of the project will add a new eastbound one-way south outer road between Route K/Main Street and Woodlawn and then continuing on to T.R. Hughes Blvd. Construction begins in May 2018 and continues through October 2019.

If you have questions or concerns about this project, please contact Vicky Usery at 636-379-5596.

Construction Update

Construction began in May 2018. Important points with this stage of construction are:

  • East Terra will be closed to traffic starting on June 18, 2018, and will remain closed until early August. The contractor will be installing the new slip ramp in this area. Once this area re-opens in August, East Terra will become one way only (westbound). For a detour route, drivers may utilize Veterans Memorial Parkway between Highway K and Belleau Creek. Harmony Lane will also be closed. The residents in that subdivision can still exit via Hilltop Way and drive to the east to TR Hughes Blvd.  Sonderen road will remain open over the overpass, however access to East Terra from Sonderen will be blocked off.
  • Construction on the new south outer road will be starting once the final utilities are adjusted. That work is expected to continue until late Fall 2018.
  • In July, the City’s street department will be connecting Vine Street to the Sonderen Loop road.

Other documents

Current Construction Update (PDF)


Overall Project Exhibits


Phase 2

Phase 2 Schedule (Dates are tentative)

  • Right-of-Way Acquisition – April 2018 – November 2018

  • Final Plans – November 2018
  • Bid for Construction – January 2019

Phase 2 Project Exhibits

Phase 2 Milestones Completed


Route Maps (PDFs)


Find out more about the I-70 Improvement Project through O'Fallon. 

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