Interstate 55 is a major Interstate Highway in the central United States. As with most Interstates that end in a five, it is a major cross-country, north–south route, connecting the Gulf of Mexico to the Great Lakes. The highway travels from LaPlace, Louisiana, at I-10 to Chicago, Illinois, at U.S. Route 41 (US 41, Lake Shore Drive), at McCormick Place.
The section of I-55 between Chicago and St. Louis was built as an alternate route for U.S. Route 66 (US 66). The Interstate crosses the Mississippi River twice: once at Memphis and again at St. Louis.