Passenger rail terminology
Various terms are used for passenger railway lines and equipment; the usage of these terms differs substantially between areas:
Chicago Transit Authority Chicago "L" tracks in the Chicago Loop at the Adams/Wabash station at night
A 2600 series car brings up the rear of a Red Line train (temporarily rerouted through the elevated tracks of the Chicago Loop) at Randolph/Wabash.
Parry People Mover ultra light rail on Stourbridge Town branch line
An interurban tram from the Philadelphia & Western Railroad, which survived long in the interurban business
Rapid transit or mass rapid transit (MRT), also known as metro, is a type of high-capacity public transport that is generally built in urban areas. A rapid transit system that primarily or traditionally runs below the surface may be called a subway, tube, or underground. Unlike buses or trams, rapid transit systems are railways, usually electric, that operate on an exclusive right-of-way, which cannot be accessed by pedestrians or other vehicles. They are often grade-separated in tunnels or on elevated railways.
The London Underground is the world's first and oldest rapid transit system.
The New York City Subway is the world's largest single-operator rapid transit system by number of metro stations, at 472.
A crowded Paris Métro average station platform in 2007
A station of the Guangzhou Metro in 2005