Chicago Midway International Airport (IATA: MDW, ICAO: KMDW, FAA LID: MDW) 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 Chicago metropolitan area and the state of Illinois, serving 22,027,737 passengers in 2018. Traffic is currently dominated by low-cost carrier Southwest Airlines; Chicago is Southwest's largest focus city. Originally named Chicago Municipal Airport, it was renamed to honor the Battle of Midway. The now-defunct Midway Airlines that once serviced the airport took its name from the airport, not vice versa. The airfield is located in a square mile bounded by 55th and 63rd Streets, and Central and Cicero Avenues. The current terminal complex was completed in 2001. The terminal bridges Cicero Avenue and contains 43 gates with facilities for international passengers. Stevenson Expressway (I-55) and the CTA Orange Line provide freeway and rapid transit access to The Loop.