Discover a New Route to St. Charles

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I-70 at Fifth Street & Fairgrounds Improvement Project

What will the project include?

  • A Diverging Diamond Interchange at the intersection of Fifth Street and Interstate 70
  • Construction of a new one-way outer road between Fifth Street and Fairgrounds Road
  • Replacement of the Fairgrounds Road overpass
  • Full interstate access to and from Fairgrounds Road
  • A roundabout at the intersection of Fairgrounds Road and Veterans Memorial Parkway
  • The addition of a fourth through lane on eastbound and westbound I-70 under Route 94
  • New sidewalks along Fifth Street, Veterans Memorial Parkway and Fairgrounds Road
  • New bike lanes at the Fairgrounds Road overpass


Why is the project needed?

The project will help improve traffic flow, as well as access to and from Interstate 70 at the very busy Fifth Street interchange.  This will improve the overall safety of the area and provide better access to a variety of St. Charles County's top attractions, including the Ameristar Casino, Historic Main Street, and the St. Charles Convention Center.

What kind of traffic impacts will there be?

The project will require nighttime and weekend lane restrictions, as well as the narrowing of Interstate 70 in both directions. 

Other impacts will include:

  • An around-the-clock lane closure on westbound I-70 between Fifth Street and Route 94 from late March to late May
  • An around-the-clock lane closure on westbound I-70 before Fifth Street in early spring
  • An around-the clock lane closure on eastbound I-70 in early spring
  • A 120-day closure of the Fairgrounds Road bridge in late spring 2016
  • A weekend closure of 5th Street in fall 2016
  • The closure of the commuter lot at Fairgrounds and I-70 throughout the project.  The nearest commuter lot is at I-70 and Zumbehl Road.

Crews will limit impacts on holidays and large scale events such as the Festival of Little Hills.

Alternate Routes include:

The Route 370 (Discovery Bridge) and Route 364 (Veterans Memorial Bridge) are the primary alternate routes to use to avoid congestion on I-70 during the construction.  Both bridges are located within a few miles of I-70 and provide an easy alternative to get to and from St. Charles and St. Louis counties as well as in and out of the major business and shopping districts in downtown St. Charles and Earth City. 

Visit to view project information and to sign up for email updates.  MoDOT reminds motorists to slow down in work zones and avoid distractions to keep yourself and the workers safe.