Interstate 55 (abbreviated I-55) is an interstate highway in the central United States. Like other interstates, it is commonly referred to as I-55. Its odd number indicates that it is primarily a north-south highway. It goes from Laplace, Louisiana (some 25 miles (40 km) west of New Orleans) at Interstate 10 to Chicago, Illinois at U.S. Route 41 (Lake Shore Drive) next to McCormick Place.
In the Chicagoland area the expressway is referred to as the Adlai E. Stevenson Expressway in honor of one of Illinois' favorite sons. The general public uses both I-55 as well as "The Stevenson" to refer to this freeway in the Chicagoland metropolitan area. In the St. Louis, Missouri metropolitan area I-55 is known as the "Rosa Parks Highway" although the general public still refers to it as I-55.
The section of Interstate 55 between Chicago and St. Louis was built as a bypass for U.S. Highway 66.