U.S. Route 40 in Missouri

U.S. Route 40
U.S. Route 40
	US 40 highlighted in red
Route information
	Maintained by MoDOT
Existed	1926–present
Major junctions
West end	I-70 / US-24 / US-40 / US-169 in Kansas City
	I-35 in Kansas City; I-29 / I-35 / US 71 in Kansas City; I-70 in Kansas City; I-70 at Kansas City–Independence line; I-70 in Grain Valley; I-70 / I-70 BL / Route 5 in Boonville; I-70 / Route 240 near Rocheport; ; I-64 / I-70 / US 61 in Wentzville; I-44 / I-55 in St. Louis;
East end	I-55 / I-64 / US 40 in St. Louis
Location
Country	United States
State	Missouri
Counties	Jackson, Lafayette, Saline, Cooper, Howard, Boone, Callaway, Montgomery, Warren, St. Charles, St. Louis, City of St. Louis
Highway system
	United States Numbered Highway System; List; Special; Divided; Missouri State Highway System; Interstate; US; State; Supplemental;

U.S. Route 40 (US 40) in the state of Missouri is a U.S. highway that runs from Kansas City to St. Louis. Outside of Greater St. Louis, much of the route either parallels or runs along I-70. East of Wentzville in Greater St. Louis, the route runs along I-64.