I-70 5th St. to Rte 94

St. Charles, MO

Services Performed

Bridges, Concrete Paving, Earthwork, Drainage, and MSE Walls

Project Owner



2016 AGCMO – Keystone Award Finalist – General Contractor Transportation and Infrastructure – Project Under $25 Million

Project Overview

In February of 2016, MoDOT awarded Millstone Weber a $20.8 million contract for significant construction improvements along I-70 from Route 94 to 5th Street in St. Charles.

The project consisted of 2 bridges, 6 MSE walls, 225,000 CY of excavation, 9800 LF of pipe with structures and 84,000 SY of concrete paving. A new bridge was constructed at Fairgrounds along with a full access interchange. The existing interchange at 70/5th Street was converted to a diverging diamond. New ramps were constructed and the existing roadway was widened to accommodate the change. New one way outer roads were built between Fairgrounds and 5th Street. Also a 4th through lane was added on EB and WB I-70 at Route 94 along with reconstructing the 70/94 interchange ramps.

Construction on this fast paced project started in March of 2016. There were 3 contract milestones that had to be met: Fairgrounds could only be closed for 90 days to construct the new bridge, the Diverging Diamond interchange and all ramps at I-70/5th had to be open by Novemeber 23rd and all lanes on the project had to be open by April 22nd. Millstone Weber met the 1st two milestones and had all other roadways and ramps, except one, open by December 7th. The only ramp not open to traffic is the Fairgrounds on ramp to EB 70. It is excepted to be opened as soon as weather allows barrier wall to be slipped and striping to be completed, well before the April 22nd deadline.

The staging plans included in the construction plans could not be followed, as the tight time frame in which the contract required the work to be completed could physically not have been met. Millstone Weber came up with their own sequencing for the work in order to fit the construction in the allotted time frame of the contract, while abiding by all contractural provisions. They then worked diligently with MoDOT, the City of St. Charles and St. Charles County to mitigate any concerns to make the plan work.