Hawaii's main gateway airport, Honolulu International Airport (HNL) ranks as the 27th-busiest airport in the United States, with approximately 17.9 million passengers using the airport in 2013. Located three miles northwest of Oahu's business district, the airport serves as a hub for Hawaiian Airlines, Island Air and Mokulele Airlines. Passengers can fly non-stop between HNL and other Hawaiian islands, the mainland United States, elsewhere in North America, as well as Asia and Oceania. Honolulu Airport has four asphalt runways and two water runways, as well as three terminals: The Commuter Terminal, the Interisland Terminal and the Main Overseas Terminal. Parking is available near each of the terminals; there is also a cell phone waiting area. Ground transportation options include rental cars, taxis, buses and shuttles.