owned and operated by the City of St. Louis, is 11 miles northwest of downtown along highway I-70 between I-170 and I-270 in St. Louis County. It is the largest and busiest airport in the state. In 2016, when the airport had more than 255 daily departures to about 90 domestic and international locations, it served more than 15 million passengers. The airport serves as a focus hub city for Southwest Airlines; it was once a hub for Trans World Airlines and a focus-city for American Airlines and AmericanConnection. The airport has two terminals with a total of five concourses. International flights and passengers use Terminal 2, whose lower level holds the Immigration and Customs gates. Passengers can move between the terminals on complimentary buses that run continuously, or via MetroLink for a fee. It was possible to walk between the terminals until Concourse D was closed in 2008. MidAmerica St. Louis Airport is the secondary passenger airport serving the metropolitan area. Located 17 miles east of the city downtown core, the airport serves domestic passengers. Air cargo transportation is available at Lambert International and at other nearby regional airports, including MidAmerica St. Louis Airport, Spirit of St. Louis Airport, and St. Louis Downtown Airport. Port authority River transportation is available through the Port of St. Louis, which is 19.3 miles of riverbank on the Mississippi River that handles more than 32 million tons of freight annually. The Port is the second largest inland port by trip-ton miles, and the third largest by tonnage in the United States, with more than 100 docks for barges and 16 public terminals on the river. The Port Authority added two new small fire and rescue craft in 2012 and 2013. Railroad service Inter-city rail passenger train service in the city is provided by Amtrak at the Gateway Multimodal Transportation Center downtown. Amtrak trains terminating in the city include the Lincoln Service to Chicago and the Missouri River Runner to Kansas City, Missouri. St. Louis is an intermediate stop on the Texas Eagle route which provides long-distance passenger service between Chicago, San Antonio, and three days a week, to Los Angeles. St. Louis is the nation's third largest freight rail hub, moving Missouri exports such as fertilizer, gravel, crushed stone, prepared foodstuffs, fats, oils, nonmetallic mineral products, grain, alcohol, tobacco products, automobiles, and automobile parts. Freight rail service in St. Louis is provided on