Passenger rail terminology

Various terms are used for passenger rail lines and equipment-the usage of these terms differs substantially between areas:

Rapid transit

A rapid transit system is an electric railway characterized by high speed and rapid acceleration. It uses passenger railcars operating singly or in multiple unit trains on fixed rails. It operates on separate rights-of-way from which all other vehicular and foot traffic are excluded (i.e. is fully grade separated from other traffic). It uses sophisticated signaling systems, and high platform loading.

Originally, the term rapid transit was used in the 1800s to describe new forms of quick urban public transportation that had a right-of-way separated from street traffic. This set rapid transit apart from horsecars, trams, streetcars, omnibuses, and other forms of public transport.

Though the term was almost always used to describe rail transportation, other forms of transit were sometimes described by their proponents as rapid transit, including local ferries in some cases.