Districts Impacted
I-270 Gap Project
MoDOT is working to improve a three-mile section of Interstate 270 in north St. Louis County that has not been touched by either the I-270 North Project or the Chain of Rocks Bridge rebuild. The project is currently in the design phase.
The project will include the rehabilitation or replacement of:
- I-270 bridges over Route 367 (Replacement)
- I-270 bridges over Bellefontaine Road (Replacement )
- I-270 bridges over BNSF railroad (Rehabilitation)
- Dunn Road bridge over BNSF railroad (Rehabilitation)
- Lilac bridge over I-270 (Replacement )
Along with the bridge work, the project will also include the expansion of I-270 from two continuous lanes to three from Lilac to Route H (Hall St.). Signal and ADA improvements will be made at the Lilac and Bellefontaine interchanges.
The project will wrap up with the resurfacing of I-270 from Route 367 to the Chain of Rocks Bridge.
Project Milestones
The improvements are expected to be split into two different projects:
Project 1
Project lettings anticipated to begin – Spring 2026
- I-270 bridges over Route 367
- I-270 bridges over Bellefontaine Road
- Lilac Ave. bridge over I-270
- I-270 widening from Lilac Ave to Route H
Construction Anticipated to End: 2029
Project 2
Anticipated Start of Construction – Fall 2028
- Dunn Road bridge over BNSF railroad
- I-270 bridges over BNSF railroad
- I-270 and Outer Road Resurfacing from Route 367 to Route H
Construction Anticipated to End: 2030
Frequently Asked Questions
What is being done in this area?
MoDOT is rehabbing or replacing bridges that were not included in the I-270 North Design-Build project. That includes the I-270 bridges over Route 367 (Rehab or Replacement), over Bellefontaine Road (Replacement Only), over the BNSF railroad (Rehab Only) and the Lilac Bridge over I-270. The project also includes the rehab or replacement of the Dunn Road bridge over BNSF railroad, as well as the expansion of I-270 from two continuous lanes to three from Lilac to Route H. Modifications to the ramps at Lilac will also be made. Finally, the project includes culvert rehabilitation near Route AC and the resurfacing of I-270 from Route 367 to Chain of Rocks Bridge.
When will work begin?
The projects are currently scheduled to begin construction in 2026.
How long will the work take?
Construction will proceed through the 2028 construction season.
Will all the work be done at the same time?
No, it is anticipated the projects will be split into two projects with one beginning in 2026 and the other in 2028. An exact timeline of when the projects will be done will be available closer to construction beginning.
What is the cost of the project?
To complete all of the projects, the current STIP has allocated approximately $50 million. The breakdown of costs is as follows:
- $32 million is for the I-270 bridges
- $13 million is for the replacement of the Lilac interchange and the addition of a third lane on I-270
- $3 million is for resurfacing
Why wasn’t this work done with all the other construction in the area?
The work was not all done at one time due to funding constraints from both the total amount of construction dollars needed and the sources of the funding. The Chain of Rocks Bridge project was funded jointly by MoDOT and IDOT and was constructed out of sequence with the improvement of the I-270 North Design-Build project.
WHO TO CONTACT

Tabitha Locke
Title
Area Engineer, North St. Louis County
Department
St. Louis District
Contact Info
Office: (314) 453-1749
Email: Tabitha.Locke@modot.mo.gov
Office: (314) 453-1749
Email: Tabitha.Locke@modot.mo.gov

Daniel Savageau
Title
Project Manager, North St. Louis County
Contact Info
St. Louis District
Phone: 314-453-5089
Email: daniel.savageau@modot.mo.gov
St. Louis District
Phone: 314-453-5089
Email: daniel.savageau@modot.mo.gov