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:

  • MoDOT has closed the T.R. Hughes ramp to westbound I-70. The ramp will be relocated as part of the I-70 improvement project going on between T.R. Hughes and Route K.  The new, relocated ramp will reopen later this year. Drivers can detour around the ramp closure by either taking the I-70 North Outer Road (East Terra) to Route K or taking Mexico to Route K. Please allow yourself extra time while using these detour routes as the extra traffic could cause delays.  
  • The contractor has been diligently working on East Terra (north outer road) and the road will be open as of Wednesday, August 1 (late in the day). The newly opened road will be opened to west-bound traffic only from TR Hughes to Main Street, as this is the permanent layout. There are a couple of message boards installed along the route to help provide that notice, as well.
  • The work that the Streets Department has been doing to connect Vine Street to the Sonderen Loop road will also be opened to traffic on August 1, which will result in further improved connectivity.
  • After August 1, work will immediately shift to East Terra, just west of TR Hughes. You may have already seen construction barriers in place. This section will be worked on until November/December to build the west-bound slip ramp to exit I-70 onto East Terra Ln.
  • Work on the south outer road also continues and should be completed before the end of this year.
  • Thank you for everyone’s cooperation in mitigating the traffic this summer. We had several meetings with the Fort Zumwalt School District and Economic Development also provided helpful updates to the businesses along the corridor.

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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