JEFFERSON COUNTY – The Missouri Department of Transportation (MoDOT) is beginning a major rehabilitation project on the I-55 Meramec River Bridge, with construction scheduled to start Tuesday, March 24.
Motorists should expect nightly lane closures on both northbound and southbound I-55 between 7 p.m. and 5 a.m. These closures are necessary for restriping operations and installation of barrier walls ahead of the traffic shift.
Crews will then shift both northbound and southbound I-55 lanes between Route 141 and Meramec Bottom Road. A minimum of four lanes will remain open in each direction by restriping and narrowing all lanes to 11 feet during this work. Additionally, during this stage of construction:
- Northbound I-55 will be reduced from five lanes to four lanes
- Southbound I-55 will maintain five lanes in a split traffic pattern:
- Two left lanes will cross over into the northbound side of the interstate
- Three right lanes will remain on the southbound side
- Portions of the median barrier will be removed to safely shift traffic.
This work is part one of a multi-phase, three-season project designed to extend the life of the bridge and improve safety for the traveling public. Work will take place over three years and includes:
- 2026: Southbound bridge deck rehabilitation
- 2027: Northbound bridge deck rehabilitation
- Spring 2028: Final bridge washing and project completion
This work will continue through July 2026, at which point traffic will be redesigned for stage two. Lane shifts will remain in place through November 2026.
For updates on this project and real-time traffic conditions, visit MoDOT’s website or follow regional traffic alerts. Interstate 55 Bridge Rehabilitation in Jefferson and St. Louis Counties | Missouri Department of Transportation
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