Multiple realities(covers information from several alternate timelines)
A tram is a type of street vehicle designed for public transportation. They were common in San Francisco.
By the 23rd century, air trams, trams capable of atmospheric flight, were in common use, although the traditional street variety were also still in use. (Star Trek Into Darkness)
The Federation had their own air tram stations. Starfleet personnel were transported to Starfleet Headquarters through this method of transportation. (Star Trek: The Motion Picture)