The first phase of construction was completed with a western terminus at Route 94 in St. Charles; the freeway opened to traffic on December 14, 2003.

Immediately after this interchange, the Veterans Memorial Bridge carries ten lanes of Route 364 over the Missouri River, where it enters St. Louis County and the Maryland Heights city limits.

The opening of the bridge increased the number of lanes across the Missouri River in the St. Louis metropolitan area from 23 to 33.

The ten-lane freeway winds through the Maryland Heights suburbs for a few miles, crossing under overpasses at Seven Pines Drive and Amiot Drive before interchanging with Bennington Place, which runs north through residential Maryland Heights and south to Fee Fee Road in Creve Coeur.

An earlier alignment, called the Green Line, bypassed Creve Coeur Lake Memorial Park and took the freeway to I-70, but it could no longer be considered due to the rapid growth of the city of St. Peters and because the park expanded in size and encroached on the proposed alignment anyway.

The committee proposed a new alignment called the Red Line and the Missouri Department of Transportation (MoDOT) authorized the project in the fall of 1986.

The United States Congress passed legislation in October 1992 authorizing the project as part of the Pipeline Safety Act of 1992.

[2] The environmental impact study was completed in November 1992, but, just before the project was to receive final clearance from the federal government, Secretary of the Interior Bruce Babbitt took office and ordered more environmental studies resulting in more land mitigation for intrusion into Creve Coeur Lake Memorial Park.

In the fall of 1995, the federal government gave the final clearance for the project 11 years after active planning began.

For nearly 27 years, the roadway was simply referred to as the Page Avenue Extension, but in February 1996 MoDOT gave the freeway an official designation of MO-364.

[3][4] Phase I included work from I-270 to Route 94 through the Creve Coeur Lake Memorial Park, but due to concerns with traffic congestion at the proposed terminus with MO-94 it was decided to extend the freeway further west along its concurrency with MO-94 to Harvester Rd.

Following the various speeches and ribbon cutting, a ceremonial first drive occurred between Upper Bottom Rd/Arena Parkway and Maryland Heights Expressway.

Completion of Phase II had originally been proposed to happen in segments with each interchange constituting a separate project.

However, the American Recovery and Reinvestment Act of 2009 accelerated that project and included funding for the segment to construct the Central School Road interchange.

The final Phase II projects including grade separated interchanges at Kisker Rd and Mid Rivers Mall Drive were approved and funded shortly thereafter.

[10][11] MoDOT, St. Charles County and local municipalities teamed together to allocate $118.2 million towards building Route 364/Page Phase 3.

The Missouri Highways and Transportation Commission approved the contract on February 6, 2013, awarding the project to the Page Constructors Joint Venture, which includes Fred Weber Inc. and Millstone-Bangert Inc (now known as Millstone Weber) along with Kolb Grading and lead designer, Parsons Transportation Group.

[15] Its high cost and debate over urban sprawl forced many St. Louis County municipalities to pass resolutions opposing the freeway.