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 began in May 2018 and continues through October 2019.

If you have questions or concerns about this project, please contact Jeff Schuepfer, Assistant City Engineer, at This email address is being protected from spambots. You need JavaScript enabled to view it. or 636-379-5491.

Construction Update

Important points with this stage of construction:

  • The I-70 Outer Road contractor has modified the ramps along the I-70 corridor. The two new slip ramps along East Terra have opened and the original exit ramp from westbound 70 to the Main Street/Highway K interchange were removed from service. All westbound traffic exiting I-70 for Main Street/Highway K is now exiting at the new slip ramp, just west of the TR Hughes interchange. The new on-ramp also is open near the Sonderen overpass.

    Click here to see a detailed map of the changes. (PDF)

  • Work on the south outer road also continues and should be completed in the coming weeks.

Overall Project Exhibits


Phase 2

Phase 2 Schedule (Dates are tentative)

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

  • Final Plans – December 2018
  • Bid for Construction – February 2019

Phase 2 Project Exhibits

Phase 2 Milestones Completed


Route Maps (PDFs)



Contact Engineering staff

Jeff Schuepfer, Assistant City Engineer This email address is being protected from spambots. You need JavaScript enabled to view it. 636-379-5491