AirTrain (San Francisco International Airport)

AirTrain

Company type	Public transportation
Industry	Transportation
Founded	February 24, 2003 (2003-02-24)
Headquarters	San Francisco , United States
Area served	San Francisco International Airport
Products	Automated people mover system

AirTrain is a fully automated people mover system serving San Francisco International Airport (SFO), which commenced operations on February 24, 2003. Operating continuously around the clock, it consists of two separate routes spanning a combined distance of . This complimentary transit service is financed through fees imposed on rental car users. Since the system functions outside the terminals' sterile area, passengers must undergo security screening when moving between terminals.

Lines and stations

The AirTrain network includes two lines: the Red Line and the Blue Line, each arriving approximately every four minutes. The Red Line travels clockwise in a loop around the central terminal complex, completing its circuit in roughly nine minutes. Conversely, the Blue Line runs counterclockwise along the same stops in reverse order, extending service to West Field Road, the Rental Car Center, and long-term parking areas, with a total loop time of about 25 minutes.

Station	Lines	Notes
Grand Hyatt at SFO	Red Line   Blue Line	Airport hotel
Garage A
International Terminal A
Harvey Milk Terminal 1
Terminal 2
Terminal 3
International Terminal G
Garage G / BART		Connection to Bay Area Rapid Transit
West Field Road	Blue Line	Facilities for air cargo and employee parking
Rental Car Center
Long-Term Parking

At the International Terminal, stations are situated one level above ticketing counters at both ends of the main concourse. Stations serving Terminals 1, 2, and 3 are positioned on level 5 within the domestic parking garage and are reachable via mezzanine-level skybridges near security checkpoints B, D, and F. Garage A and Garage G stations are located on level 7 of their respective garages. The long-term parking station connects through a skybridge to level 5 of its parking structure.

Technical details

Constructed by Bombardier Transportation at an investment of US $430 million, the AirTrain fleet comprises 38 Innovia APM 100 vehicles arranged in trains of up to three cars. These same models are utilized in automated people mover systems at airports including Tampa, Denver, Atlanta, Seattle-Tacoma, Houston, and Madrid. The network operates under Bombardier's Cityflo 650 Communications-based train control system, notable for being among the earliest radio-based train control implementations. All vehicles are designed for accessibility and permit passengers to bring rented baggage carts onboard.

According to the 2016 Airport Development Plan, passenger demand was projected to surpass existing capacity by 42% on the Red Line and by 87% on the Blue Line. To address this anticipated overcrowding, recommendations included procuring an additional 30 AirTrain cars, enlarging stations to accommodate four-car trains, and enhancing maintenance facilities to support a larger fleet.

History

A $15 million infill station was constructed to provide access to the Grand Hyatt hotel located at SFO airport, which commenced operations on October 7, 2019.

Initially, AirTrain did not extend service to SFO's long-term parking facility; instead, passengers relied on a complimentary shuttle bus connecting the terminals with parking areas. Service to the long-term parking garage began in May 2021 following a track extension, which replaced the shuttle buses and reduced an estimated 600,000 miles of annual bus travel.

The Harvey Milk Terminal 1 station was closed for renovations from July 2021 until it reopened on April 26, 2023, coinciding with terminal reconstruction efforts.

See also

• Airport rail link
• Oakland Airport Connector