Air tram 14 was a 23rd century Federation air tram operated by Starfleet. It was attached to Starfleet Command on Earth.
In the 2270s, this air tram, the closest to air tram 3, was parked with its port side doors open in the Starfleet Headquarters air tram station in San Francisco. (Star Trek: The Motion Picture)
In the director's edition DVD release of the movie, air tram 14 was changed in appearance, and the hull number was no longer visible. (Look here{{dead link}} to view air tram 14's original appearance and/or here to see its revised appearance.)