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 Vicky Usery at 636-379-5596.

Construction Update

Important points with this stage of construction are:

  • From July 2 to July 21, the contractor plans to continue working on the north outer road. The detention basin cells will be installed and the intersection and on-ramp should start to be paved by the end of the month.
  • East Terra will be 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 T.R. Hughes Blvd. Sonderen Street will remain open over the overpass, however access to East Terra from Sonderen will be blocked off.
  • The Vine Street connection will open when the closure to the Outer Road is lifted.
  • The contractor is anticipating the North Outer Road opening by August 4.
  • Soundwall pier shafts will be starting in late July.
  • Drainage, excavation and retaining walls will be under construction on the South Outer Road in late July/early August.

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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