ST. CHARLES COUNTY, Mo.—Commuters in St. Charles County will have another “diverging diamond” to get used to on area highways, starting with Thursday afternoon’s rush hour.

What You Need To Know

  • The $20 million project makes major improvements to the corridor between I-70 and the Route 94/Highway 364/Muegge Road interchange.

  • It features a diverging diamond format, similar to what's found along I-70 at Fifth Street and I-70 at Mid Rivers Mall Drive.
  • The project costs were split between St. Charles City, St. Charles County, the state of Missouri and the federal government, with the largest single amount ($7M) coming from St. Charles Co.

  • The project should be open to drivers in time for the Thursday afternoon rush.

Officials on Wednesday celebrated the completion of a $20 million project to add a third lane of traffic in both directions on Route 94 between Interstate 70 and the Route 94/Highway 364/Muegge Road interchange, plus a new wider Muegge Road bridge over 94.

The new interchange, with the diverging diamond format, means drivers can travel in both directions on Route 94 to northbound Muegge Road and southbound on Muegge Road to both directions of 94.

“Traditionally your’re on the right side of the bridge…you’ll be on the left side of the bridge. You won’t really notice it, it really won’t make a difference but it helps facilitate a left turn, left turn movements, it cuts down on conflict points,” said Andrew Tuerck, the Missouri Department of Transportation’s area engineer for St. Charles County.

“This is a magnificent change it’s going to help us all the way back to I-70 which is important,” St. Charles Mayor Dan Borgmeyer said. “This is a huge step in facilitiatiiong the traffic across St. Charles County and things like that.” 

The project, which broke ground in November of 2021, finished ahead of schedule by a few months. It was paid for by a combination of St. Charles, St. Charles County, state and federal funds, with the largest share being $7 million from St. Charles County.

Other diverging diamond projects in St. Charles County can be found at I-70 and Fifth St. and I-70 and Mid Rivers Mall Dr. 

Crews will be out picking up traffic cones and doing last-minute touch-ups and re-striping ahead of the expected opening to traffic Thursday afternoon.