Interstate 364 Missouri

I-364 Missouri


Missouri Highway 364 is the Page Avenue Extension, a freeway running west from Interstate 270 at Maryland Heights to I-64 through the St. Charles County suburbs. The numbering corresponds with Interstate 64 to the south, but is otherwise coincidental. No plans are in place to add Highway 364 to the Interstate Highway system.


The first phase of Highway 364 built was the Veterans Memorial Bridge over the Missouri River, which opened on December 13, 2003.1 East from the Veterans Memorial Bridge to Interstate 270, Highway 364 is officially designated as the “‘Buzz’ Westfall Memorial Highway,” which honors the former St. Louis County Chief Executive who had died before Phase I of the freeway opened.2

The freeway was lengthened west to Mid Rivers Mall Drive in St. Peters on August 30, 2012. Work on the remainder of Highway 364 west to I-64 at Lake St. Louis commenced in 2013. The roadway opened fully on November 1, 2014.3

Route Information

  • East End – Maryland Heights, MO

  • West End – Lake St. Louis

  • Mileage – 21.39

  • Cities – Lake St. Louis, O’Fallon, Dardenne Prairie, Weldon Spring, Cottleville, St. Peters, St. Charles, Maryland Heights
  • JunctionsI-64 I-270

Highway 364 Annual Average Daily Traffic (AADT)

Location Vehicles per day
I-64 to Exit 2 28,980
Exits 8B to 13 77,985
Exits 13 to 14 85,400
Exits 14 to 17 87,741
Exits 17 to 19 41,931
Exits 19 to 20 85,200

Aerial image of I-64/U.S. 40-61 at County Highway N in O’Fallon. Ramp stubs were built into the interchange for the eventual Missouri Highway 364 freeway extension. Land was also cleared for the corridor eastward, including a stretch of County N and South Outer Road 364.

 Photo Guides


  1. “Snow is Already Halting Traffic on Bridge – and it’s Not Even Open Yet.” St. Louis Post-Dispatch (MO), December 13, 2003.
  2. Dowd, Brian. Personal email. “Mo Highway notes.” November 22, 2004.
  3. “Ceremony to mark opening of Route 364/Page Phase 3.” St. Louis Post-Dispatch (MO), October 29, 2014.

Page updated February 1, 2019.