Rapid transit

:This article is about high-capacity urban rail public transit systems. For lower-order systems, see tram, light rail, bus, and bus rapid transit.

Extent

In larger metropolitan areas the metro system may extend only to the limits of the central city, or to its inner ring of suburbs, with trains making relatively frequent station stops. The outer suburbs may then be reached by a separate commuter, suburban, or regional rail network, where more widely spaced stations allow a higher speed. These trains are often more expensive and less frequent, sometimes operating only in rush hours, and sometimes for political reasons they are operated by a separate authority that tends not to cooperate with the city's transit authority.

Related Topics:
Suburb - Regional rail - Rush hour

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Many of these regional railways were first built to operate in one direction from a city-center terminus, but some have been extended across the city center, sometimes running in tunnels. By making multiple stops in the city, they can offer suburban passengers a choice of stations, and also provide useful transportation within the city. A notable example is the Paris RER system, where (in cooperation with the city's transit authority) several pairs of existing suburban lines running in opposite directions from the city have been extended in tunnel to join up and form new through routes across the city. They are provided with frequent service and, within the city, the same fares as the Métro are charged, providing an integrated network. In German-speaking countries, such a system is called an S-Bahn. In Italian-speaking countries such a system is called Linea S or Treno Suburbano.

Related Topics:
Paris - RER - Métro - German-speaking - S-Bahn - Italian-speaking

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In some cases, such as the San Francisco Bay Area Rapid Transit (BART) and Washington Metrorail systems, the rapid transit system itself runs to the suburbs and effectively functions as a regional rail service as well. Where there are separate systems, the rapid transit system is typically a self-contained service with its own dedicated tracks and stations and technologically incompatible with other railways. Suburban rail services, on the other hand, often share tracks and stations with long-distance trains (historically they were usually operated by the same company, which also owned the rails and ran freight, although this has become less common) and are subject to the same standards and regulations. There are exceptions; some London Underground lines share track with suburban rail services. In some cases, metro lines have been extended by taking over existing regional rail lines, notably the Central and Northern Lines in

Related Topics:
San Francisco - Bay Area Rapid Transit - Washington - Metrorail - London Underground

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London. The Athens Metro's Blue Line shares tracks with suburban rail services in order to connect the metro to Eleftherios Venizelos International Airport, but does not stop at the suburban rail stations because the platforms for the stations are higher than the train's floor. In Hong Kong, metro-like frequent service on the KCR East Rail to the new towns is provided by electrifying existing railway line, while continues to share part of the tracks with the much less frequent intercity and freight trains. The KCR West Rail, on the contrary, is designed to accommodate intercity and freight traffic in future, while presently provides only metro-like service.

Related Topics:
Athens Metro - Eleftherios Venizelos International Airport - Hong Kong - KCR East Rail - New towns - KCR West Rail

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Elevated railways were a popular way to build mass transit systems in cities around the turn of the twentieth century, but they have fallen out of favour and many elevated lines were later demolished, being replaced by subways or buses. Elevated rail saw something of a resurgence in the late twentieth century, with the construction of a number of new lines such as the Docklands Light Railway in London and the Vancouver SkyTrain; in the United States a few such lines have been built, including the AirTrain JFK and the Las Vegas Monorail, but these are typically seen as more futuristic, and are not representative of the overall trends in U.S. transit development.

Related Topics:
Mass transit - Twentieth century - Bus - Docklands Light Railway - London - Vancouver SkyTrain - United States - AirTrain JFK - Las Vegas Monorail - Futuristic

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