Missouri Route 364

Route 364 begins at a cloverleaf interchange in Lake St. Louis with I-64, U.S. 40, U.S. 61 and Route N. From this point until Route 94, Route 364 is a semi-rural freeway with two lanes in each direction with a wide, grassy median between the carriageways. From I-64, the freeway turns east-southeast into Dardenne Prairie and has another interchange with Route N. From that intersection, the highway continues southeast for two miles and has a SPUI Interchange with Route K. The highway then continues several miles before entering the city limits of Cottleville. The route curves slightly to the south, crossing over a few roads and interchanging with Gutermuth Road before turning northeast toward Route 94.

Route 94 joins Route 364 through several miles of suburban developments in St. Charles County after its initial interchange. The freeway widens from just two lanes in each direction to four, and the wide, grassy median is replaced by a barrier. In St. Peters, the route interchanges with Kisker Road and Central School Road immediately after the concurrency with Route 94 begins, and then curves slightly to the northeast where it interchanges with Jungermann Road. The interchanges that take place through St. Peters and part of St. Charles utilize collector-distributor roads to the north and south of the highway, named North St. Peters Parkway and South St. Peters Parkway, respectively. The route then curves northeast, and then back towards the east before interchanging with Woodstone Drive, Harvester Road, Jungs Station Road and Heritage Crossing, all of which are accessed via St. Peters Parkway. After these intersections, the highway briefly enters the St. Charles city limits and interchanges with Route 94 and Muegge Road, marking the eastern end of the concurrency with Route 94. From there, Route 94 turns northeast into St. Charles, while Route 364 turns to the southeast towards the Missouri River.

South of the interchange with Route 94 and Muegge Road, Route 364 has a diamond interchange with Upper Bottom Road. 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.

After crossing the river, the highway descends into the floodplain southeast of the river, through which it continues southeast for a few miles before turning due east and interchanging with Route 141, which at that point is also designated as Maryland Heights Expressway.

East of the interchange with Route 141, Route 364 climbs out of the floodplain via a bridge carrying the highway over the southern tip of Creve Coeur Lake. 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. The route turns east-northeast for its final stretch before terminating at a modified cloverleaf intersection with Interstate 270.

Beyond the Interstate 270 interchange, Route 364 ends and continues as a freeway for roughly one mile signed as Route D and Page Avenue, with ramps departing for Westport Plaza Drive and Lackland Road. The freeway ends at a signalized intersection with Schuetz Road in Maryland Heights. Route D continues as an expressway for about another mile before interchanging with U.S. 67 (Lindbergh Boulevard) and becoming a road.

Route 364 spans the Missouri River with a steel through arch, suspended concrete deck bridge. Also visible in the above image is the parallel pedestrian/bike path.

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. Two major bridge structures were required, which included the Veterans Memorial Bridge and Creve Coeur Lake Memorial Park Bridge which cost $79 million and $74 million respectively. Both structures are designed to withstand seismic activity from the nearby New Madrid Fault. The total cost to construct this phase was approximately $350 million.[5]

This phase also included improvements to the Creve Coeur Lake Memorial Park. The park nearly doubled in size and an existing bike trail there was linked to the Katy Trail in St. Charles County via the Veterans Memorial Bridge. The Creve Coeur Lake was dredged and a siltation lake was added to eliminate the need for future dredging.

A ribbon cutting ceremony occurred on December 13, 2003. The ceremony was held on the eastbound lanes of the Veterans Memorial Bridge. Dignitaries that spoke included then Governor Bob Holden and Senator Christopher "Kit" Bond. Following the various speeches and ribbon cutting, a ceremonial first drive occurred between Upper Bottom Rd/Arena Parkway and Maryland Heights Expressway. Due to inclement weather, MoDOT opted to use December 13, 2003 to clear snow off the freeway and delayed opening the freeway until around 10:00 am on December 14, 2003 after the roadway was cleared.

The section of the freeway in St. Louis County has been dedicated the Buzz Westfall Memorial Freeway after former St. Louis County Executive Buzz Westfall who helped get the freeway built. Westfall died in 2003, months before the freeway opened.

A new interchange taking NB I-270 to WB MO-364 opened to traffic on July 22, 2011. This two lane ramp replaced a cumbersome cloverleaf movement which caused frequent backups on I-270.

Phase II work extended the freeway along its concurrency with Route 94 to Route N/Mid Rivers Mall Dr including a one way outer road system. Work along MO-94 from Portwest Dr to Harvester Rd was completed as part of the Phase I. This phase of construction was completed on August 30, 2012.

Completion of Phase II had originally been proposed to happen in segments with each interchange constituting a separate project. Work began on the Harvester Road interchange with grading and utility relocation in the fall of 2006.[6][7] In 2008, the Jungermann Road and Woodstone Drive interchanges had been approved, funded, and scheduled for construction in 2010. 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.[8][9]

The Harvester Road interchange opened to traffic on July 27, 2010. Phase II to Mid Rivers Mall Drive opened on August 30, 2012.[10][11]

MoDOT, St. Charles County and local municipalities teamed together to allocate $118.2 million towards building Route 364/Page Phase 3. The $118.2 million was used for purchasing property, utility relocations, design and construction. The project included building an improved connection from Page Phase 2 at Route 94 and Mid Rivers Mall Drive to I-64/US Route 40/61 at Route N. MoDOT used a Design-Build contracting process to have contractor teams compete to win the contract. 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.

Phase III extended the freeway from Mid Rivers Mall Drive/Pitman Hill Road to I-64/US-40/US-61 paralleling, but not overtaking, the existing Route N. The interchange at I-64 and Route N, which opened in October 2005, became the western terminus of the freeway upon its completion. Final approval and funding was granted in August 2011. Construction was underway from the spring of 2013 until the fall of 2014. Phase III was opened up in stages from Route 94 to I-64.[12] A segment of the highway from I-64 to Route K was opened on October 4, 2014, and the segment from Route K to Route 94/Mid Rivers Mall Drive opened on the evening of November 2, 2014.[13]

Controversy over the construction of the freeway came from several sources. The freeway's alignment would take it through the Creve Coeur Lake Memorial Park and the floodplain of the Missouri River drawing opposition from environmental groups including the Sierra Club[14] and the Missouri Coalition for the Environment.[15] Its high cost and debate over urban sprawl forced many St. Louis County municipalities to pass resolutions opposing the freeway.[16] A petition to put the freeway up for referendum was submitted in 1998, and enough signatures were collected to force a vote. On November 3, 1998, voters approved right-of-way for the freeway by a 61% margin, and construction continued.[17] In exchange, St. Louis County accepted 1,005 acres (4.07 km²) of land adjacent to the park.[18]

On February 17, 2020, work began on a new interchange with Gutermuth Road, roughly 2 miles west of the western end of Route 364's concurrency with Route 94. Situated between the Route 94/Mid Rivers Mall Drive and Route K exits, a gap that spanned nearly four miles, the new exit would provide direct connections to residential Cottleville, alleviating significant traffic burdens on roadways between those two exits. The interchange, given the exit number 6, opened on the evening of November 19, 2020.[19]

In early March 2021, construction began on slip ramps connecting Heritage Crossing.[20] The ramps will connect to westbound 364/94 and from eastbound 364/94 via North and South St. Peters Parkways, respectively.[21] The new slipramps opened on August 10, 2021.[22]

In October 2021, MoDOT awarded a contract to update the interchange between Route 364, Route 94 and Muegge Road in St. Peters, and construction began in November. The current interchange does not offer direct connection from Muegge Road to westbound Route 364/94 or to eastbound Route 94. The updated interchange aims to fix this by constructing a diverging diamond interchange at Muegge Road.[23] The new interchange was opened on June 22, 2023.[24]