Did You Know?
The I-55 expressway begins in the state of Louisiana and continues north along the Mississippi River to St. Louis, Missouri where I-55 follows the historic Route 66 corridor into Chicago. In the Chicago Area, the interstate is formally known as the Stevenson Expressway, in memory of the former Illinois state governor, Adlai E. Stevenson. Originally it was called the Southwest Expressway, as it extended from the DuPage and Cook County Line to the northeast near the I-90/94 Dan Ryan Expressway. I-55 in Illinois was opened to traffic on September 1, 1964. In 1966, the final leg of I-55 was completed connecting to US 41, also known as Lake Shore Drive.