ST. CHARLES COUNTY, MO – October 19, 2026 (STL.News) Ramp Closing – St. Charles – Drivers traveling through St. Charles County should prepare for a significant traffic change as the Missouri Department of Transportation (MoDOT) begins a scheduled 30-day closure of the ramp connecting westbound Interstate 64 to eastbound Interstate 70.
The closure affects Exit 1B at the I-64/I-70/U.S. Route 61 interchange near Wentzville. Originally scheduled to begin October 12, the closure was postponed until Monday, October 19.
The work is part of the $600 million Improve I-70: Warrenton to Wentzville project, which includes reconstruction of the interchange and improvements to approximately 20 miles of Interstate 70.
Ramp Closing – St. Charles – How Drivers Can Avoid the Closed Ramp
MoDOT has established a detour for motorists traveling westbound on I-64 who need to access eastbound I-70.
Drivers should remain in the left lane of westbound I-64 and follow Exit 1A toward westbound I-70. They should then continue to the Route Z interchange at Exit 209, use the designated interchange to turn around, and re-enter eastbound I-70.
The detour requires motorists to travel farther west before returning east, likely adding travel time, particularly during periods of heavier traffic.
MoDOT encourages drivers to pay attention to work-zone signs, follow posted speed limits, and allow extra time for their trips.
Why the Interchange Is Being Reconstructed
The I-64/I-70/U.S. Route 61 interchange is a key connection for motorists traveling between St. Charles County, the St. Louis metropolitan area, and communities farther west.
The reconstruction is part of a broader effort to modernize Interstate 70, improve highway capacity, and address aging infrastructure.
The Warrenton-to-Wentzville project will rebuild and improve portions of the interstate corridor while adding a third travel lane in each direction.
The Improve 70 Alliance team was awarded the construction contract in November 2024, with completion anticipated by the end of 2028.
A $600 Million Investment in Interstate 70
The Warrenton-to-Wentzville improvements represent the second major construction project in Missouri’s statewide Improve I-70 Program.
The broader program is supported by $2.8 billion in state general revenue approved through Missouri’s fiscal 2024 budget.
The project aims to reconstruct, rehabilitate, and expand nearly 200 miles of Interstate 70 between Blue Springs and Wentzville, including adding a third lane in each direction.
For St. Charles County, the project matters because the I-70 corridor serves commuters, commercial traffic, freight operations, and regional travelers.
Although construction creates temporary disruptions, the planned improvements are intended to increase highway capacity and support future transportation needs.
What Commuters Should Expect
The closure could affect motorists traveling from communities along the I-64 corridor toward eastern St. Charles County and the greater St. Louis area.
Drivers who routinely use Exit 1B should become familiar with the detour before approaching the interchange.
The impact will depend on traffic conditions, time of day, and other construction activity along Interstate 70.
Because the work depends on weather, the reopening date could change. A 30-day closure beginning October 19 would extend into approximately mid-November, assuming construction proceeds as scheduled.
Motorists should also watch for temporary lane restrictions and additional work-zone changes throughout the surrounding highway corridor.
Where to Find Current Traffic Information
MoDOT provides information about active construction, road closures, and highway conditions through its traveler information system.
Drivers can check the MoDOT Traveler Information Map for road conditions and work-zone updates.
The Gateway Guide traffic system also provides traffic information for the St. Louis metropolitan area.
The department advises motorists to remain alert around construction equipment, reduce speeds when necessary, and avoid distractions while navigating work zones.
Interstate 70 Improvements Continue Through 2028
The temporary closure is one component of a multiyear infrastructure project expected to continue affecting travel through western St. Charles County.
While the 30-day ramp closure will temporarily change driving patterns, the larger project is scheduled to continue through 2028.
Drivers who depend on the interchange should prioritize understanding the detour and preparing for possible delays.
MoDOT’s latest schedule calls for the closure to begin October 19, with the ramp remaining closed for approximately 30 days, subject to weather and construction conditions.
Read Local News at STL.News
Featured articles:
