Chicago Midway International Airport is a major commercial airport on the southwest side of Chicago, Illinois, located eight miles (13 km) from the Loop. Established in 1927, Midway served as Chicago's primary airport until the opening of O'Hare International Airport in 1955. Today, Midway is the second-largest airport in Chicagoland and the state of Illinois, serving 22,221,499 passengers in 2015. Traffic is currently dominated by low-cost carrier Southwest Airlines; Midway is the Dallas-based carrier's largest focus city.Originally named Chicago Municipal Airport, it was renamed to honor the Battle of Midway in 1942. The airfield is located in a square mile bounded by 55th Street, 63rd Street, Central Avenue, and Cicero Avenue, and the current terminal complex was completed in 2001. The terminal bridges Cicero Avenue and contains 43 gates with facilities for international passengers. The Stevenson Expressway (I-55) and the CTA Orange Line provide freeway and rapid transit access to the Loop.