The subway system in GTA III's Liberty City is one of two public transportation systems; there is also an elevated rail line, the Portland El, running exclusively in the borough of Portland Island. The subway features four stops dispersed throughout all three boroughs, serving as an interborough link. It provides convenient access to Francis International Airport with a subway station at the complex.
The Portland El and the subway are two separate, independent systems. There is no physical or official connection between the two services.
The subway system is a heavy rail rapid transit system that serves a large portion of the city. With 26 stops and 8 routes, it is largest and most complex rapid transit system in the Grand Theft Auto World.
The subway system has four main lines, in pairs:
These four lines serve all corners and boroughs of Liberty City, but do not serve the state of Alderney. Strangely, regardless of the route, the train will always be the "K" train with a destiantion of "Sundance St. STH. Slopes".