AirTrain JFK is an 8.1-mile-long (13 km) elevated people mover system and rail link serving John F. Kennedy International Airport in New York City. Its three lines and ten stations, operated by the Canadian firm Bombardier Transportation, connect the airport's six terminals with the New York City Subway in Howard Beach, Queens, and with the Long Island Rail Road and subway in Jamaica, Queens. In-depth planning for a dedicated transport system at JFK began in 1990, and construction commenced in 1998. The system opened in December 2003 after multiple delays. Since then, several improvements have been proposed for AirTrain JFK, including an extension to Manhattan. The system was originally projected to carry 4 million annual paying passengers and 8.4 million annual inter-terminal passengers, but the AirTrain has consistently exceeded these projections; in 2017, it had approximately 7.66 million paying passengers and 12.6 million inter-terminal passengers.