Located within the secure areas of the airport, the AGTS utilizes two mile-long tunnels traveling underneath the aircraft taxiways and passing through the center on the concourse buildings. Four stations exist, serving each airside concourse (Concourses A, B, and C) and the Terminal (which serves Ground Transportation and Baggage Claim). While it is possible to walk from the main terminal to Concourse A via a pedestrian bridge over the taxiway, the train is the only way for the public to access Concourses B and C.