Missouri Route 340

Route 340
MO 340 highlighted in red
Route information
Maintained by MoDOT
Length	19.726 mi[1] (31.746 km)
Major junctions
West end	Route 100 (Manchester Road) in Ellisville
Major intersections	I-64 / US 40 / US 61 in Chesterfield Route 141 in Chesterfield I-270 in Creve Coeur US 67 (Lindbergh Boulevard) in Creve Coeur I-170 in Olivette
East end	Ferguson Avenue in University City
Location
Country	United States
State	Missouri
Highway system
Missouri State Highway System Interstate US State Supplemental
← Route 291 → Route 350

Route 340 also called Clarkson Road or Olive Boulevard is a highway in the St. Louis metropolitan area. Its western terminus is Route 100 (Manchester Road) in Ellisville, and its eastern terminus is at an intersection with Ferguson Avenue and Olive Boulevard in University City. The stretch of Route 340 between Manchester Road and the Interstate 64 / U.S. 40 / U.S. 61 interchange is known locally as Clarkson Road. The remainder of Route 340 between this intersection and its eastern terminus is variously known as Olive Boulevard (which does not connect with Olive Street in the city of St. Louis). Route 340 ends at Ferguson Avenue in University City, but Olive Boulevard continues to Skinker Boulevard on the St. Louis city line.