JEFFERSON COUNTY – Jefferson County, in coordination with the Missouri Department of Transportation (MoDOT), will temporarily close the I‑55 northbound off‑ramp at Exit 170 beginning Monday, October 26, 2026.
This closure is a part of the continual construction on the Project Redbird South Phase 3 (U.S. 61 Roundabout), a Jefferson County initiative, located within MoDOT right‑of‑way.
Gershenson Construction Co., Inc., the contractor awarded the project, began Phase 3 construction this October 2026. The anticipated completion date is set for September 2027. The current phase includes construction of the new roundabout at U.S. 61 and the northbound I‑55 Exit 170 ramps, as well as updated pavement, striping, and signage. Periodic partial lane closures will continue throughout the duration of the project.
Message boards will be in place to notify drivers of the closure and any detour information. Motorists should expect delays and allow extra travel time while work is underway.
This effort is part of Jefferson County’s ongoing initiative to improve traffic flow and enhance safety along key corridors. Additional project details can be found on the Jefferson County website: https://www.jeffcomo.gov/m/newsflash/home/detail/205
For more information, please contact:
Jefferson County Public Works Department
Phone: 636‑797‑5573
Email: pworks@jeffcomo.org
Attachment: Project Redbird South Phase 3 – U.S. 61 Roundabout Schematic Layout
All work is weather-dependent. For up-to-date traffic and travel info, motorists can check MoDOT’s Traveler Information Map at http://traveler.modot.org/map/.
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