(covers information from several alternate timelines)
The air tram was a Federation passenger transport that was in service with Starfleet in the late 23rd century. These trams were used for transporting Starfleet personnel between air tram stations. The air tram was compartmentalized into a passenger cabin and a cockpit.
Admiral James T. Kirk was transported to Starfleet Headquarters in San Francisco aboard air tram 3 in 2273. Upon landing, the admiral met with Commander Sonak and proceeded to a meeting with Admiral Nogura. (Star Trek: The Motion Picture)