I-55 highlighted in red | ||||
Route information | ||||
Maintained by IDOT | ||||
Length | 294.38 mi[1] (473.76 km) | |||
NHS | Entire route | |||
Major junctions | ||||
South end | ![]() ![]() ![]() | |||
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North end | ![]() | |||
Location | ||||
Country | United States | |||
State | Illinois | |||
Counties | St. Clair, Madison, Macoupin, Montgomery, Sangamon, Logan, McLean, Livingston, Grundy, Will, DuPage, Cook | |||
Highway system | ||||
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Interstate 55 (I-55) is a major north–south Interstate Highway in the US state of Illinois that connects St. Louis, Missouri, to the Chicago metropolitan area. It enters the state from Missouri near East St. Louis, Illinois, and runs to U.S. Route 41 (US 41, Lake Shore Drive) near Downtown Chicago, where the highway ends, a distance of 294.38 miles (473.76 km).[2] The road also runs through the Illinois cities of Springfield, Bloomington, and Joliet. The section in Cook County is officially named the Stevenson Expressway, and in DuPage County its officially named the Joliet Freeway or the Will Rogers Freeway. The section from the south suburbs of Chicago to the area near Pontiac is officially named the Barack Obama Presidential Expressway after the 44th President, Barack Obama, who launched his political career from Illinois.[3]