Mobile Lounge?

Have you ever been to Dulles Airport and encountered their freaky "Mobile Lounge" shuttle things? You follow the arrows that say "Shuttle to Concourse C," pass through a doorway expecting a long passageway leading to a train or bus, and find yourself in a large, dead-end room with several people standing around. You know something is odd, but you're not exactly sure what. And then a huge train-like vehicle parks itself just outside the window, a vehicle filled with people like you. And you think, Wait a minute: this room IS the shuttle? A few moments later the doors close and the room (18 feet high, 53 feet long) moves away from the concourse....