A 'rapid transit', 'underground', 'subway', 'elevated', or 'metro(politan)' system is a
railway—usually in an
urban area—with a high capacity and frequency of service, and
grade separation from other traffic. In most parts of the world these systems are known as a "metro", in
London the system is called the "Underground", in
Buenos Aires the network is called Subte, while in most of
North America and in
Glasgow,
Scotland it is a "subway".
The oldest rapid transit system in the world is the
London Underground, which opened in
1863.
[1] The two primary ways that subway tunnels are constructed are by
cut and cover and
tunnel boring.
[2] The world's most extensive urban rail systems are
Tokyo's rail network and
Osaka,
Japan.
162 cities have rapid transit systems, totaling more than 8,000 km (4,900 miles) of track and 7,000 stations.
[3] 25 cities have new systems under construction.
Definition
Rapid transit is a rail-based transportation system used within urban areas to transport people. To be considered a rapid transit system, it must meet certain criteria:
★ an ''urban'', ''electric'' mass transit ''railway'' system
★ totally ''independent'' from other traffic
★ with ''high service frequency''
[4]
Elevated versus submerged
Rapid transit systems can be elevated, on ground or underground. It is quite common for the city core network to be underground, although it varies from system to system which solution is used outside the city core.
The terms 'subway' (American)
[5] and 'underground' (Outside America)
[6] are often used to describe a rapid transit that operates solely or primarily underground. In some cities the word "subway" applies to the entire system, while in others only to those parts that are actually underground, but is commonly called "Metro". Rapid transit systems that are above street level may be called "elevated" systems in the US (often shortened to ''el'' or ''L'', as
Chicago's system is popularly referred to). In the UK, elevated systems are generally classified as
light railways such as the
Docklands Light Railway (DLR) in east London, although not all British light railways are elevated.
Uses and developments
Rapid transits are generally used in metropolitan areas to transport large numbers of people at high frequency. The extent of the rapid transit system varies greatly between cities, and there are multiple transport strategies that can take advantage of a rapid transit system. In larger metropolitan areas the underground 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 higher speeds. These trains are often more expensive, less frequent, and in some cities, operate only during
rush hour periods.
It is common for rapid transit systems to be supplemented with other systems, either
buses,
trams and/or commuter trains. Because of the high density structure of the rapid transit, short haul trips are often more easily performed with tram lines or buses. Many cities have chosen to operate a tram system in the city core with the metro expanding beyond it. A typical example of this is
Oslo that features a city core transport with trams, the metro stretching beyond the core to the city limits and commuter trains serving neighbouring boroughs.
[7] Another common strategy is to use a bus feeding system to transport people to the transit stops and use the transits to carry them to the city centre or other bus routes. Using this system highly enhances the suburban bus system, since they are not required to drive all the way to the city centre.
Vancouver utilises this strategy very efficiently.
[8]
Rapid transit is a common application of elevated railways. Some systems such as the
SkyTrain in Vancouver are primarily above ground although there are underground stations downtown
Elevated railways were a popular way to build
mass transit systems in cities around the beginning of the
twentieth century, but they have fallen out of favour. Many elevated lines were later demolished and 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[9] and the
Bangkok Skytrain;
[10] in the
United States a few such lines have been built, including the Atlanta's
MARTA,
[11] New York's
AirTrain JFK[12] and the
Las Vegas Monorail,
[13] but these are typically seen as more
futuristic, and are not representative of the overall trends in U.S. transit development, predominantly because these cities are building brand new rapid transit systems.
Integration with commuter trains
Beyond the extent of the metro, many cities use commuter trains. Many of these regional railways were first built to operate in one direction from a city centre terminus, but some have been extended across the city centre, sometimes running in tunnels. They offer suburban passengers a choice of stations and also provide useful
transportation in the city. A notable example is the
Paris RER system, where (in co-operation with the city's transit authority) several pairs of existing suburban lines running in opposite directions from the city have been extended in tunnels to join and form new routes across the city.
[14] They are provided with frequent service and, within the city, the same fares as the
Métro are charged, providing an integrated network. The Paris style system is often called
S-Bahn (in
German), Linea S or Treno Suburbano (
Italian) and
CercanÃas (
Spanish). In Europe these systems are or have often been operated by the state railway.
In some cases the rapid transit system runs to the suburbs and effectively functions as a regional rail service as well. Examples are the
San Francisco Bay Area Rapid Transit (BART)
[15] and
Washington Metrorail systems, though both are supplemented with other commuter train services. 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 carried freight, although this has become less common) and are subject to the same standards and regulations.
There are exceptions; some
London Underground lines share tracks with suburban rail services. In some cases, underground railway lines have been extended by taking over existing regional rail lines, notably parts of the Central and Northern Lines in London. (It also happens the other way round, as in the case of
East London Line.) The
Tyne and Wear Metro in the North East of England is another metro service which shares some of its tracks with suburban rail services. The extension of the system to Sunderland sees the metro sharing tracks with Northern train services between Sunderland and Pelaw.
[16]
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 of the stations are much lower than the trains' floors.
[17] In
Australia, no dedicate metro exists, but regional railways serve also within the city centres, and they operate in the city centres like metro.
In
Hong Kong (
KCR East Rail) and
São Paulo,
Brazil, metro-like frequent service is provided by electrifying existing railway lines, while continuing to share the tracks with the much less frequent intercity and freight trains. The
KCR West Rail in Hong Kong is designed to accommodate intercity and freight traffic in future, whilst at present provides only metro-like service.
[18] The
Tung Chung Line on the
MTR of Hong Kong serves between the urban centres on Hong Kong Island and Kowloon with the bedroom community of
Tung Chung, yet the service is also essentially metro.
In
South Korea, the
Seoul Subway Line 1 runs on the existing
Gyeongbu,
Gyeongin and
Gyeongwon lines of the Korean Rail (
Korail), and the subway (largely overground) shares tracks with the main line trains. In the Nationalist Republic of
Taiwan, however, the existing main line trains and stations of the
Taiwan Railway are demolished and replaced by metro lines following roughly the same routes (such as the
Tamsui Line, see or ). In
Tokyo and
Osaka, Japanese private companies operate the world's most extensive suburban railways, each with their own fare system that integrates with the entire system.
Similarities to light rail
Main articles: Light rail
Metro system of Amsterdam
There has always been some crossover between rapid transit and "lighter"
streetcar/tram systems. For example, some lines of the
Brooklyn Rapid Transit Company in
New York City were elevated in built-up areas and ran at street level, often along streets, in less crowded areas. In many German cities, such as
Hanover, the opposite applies, with
trams descending into tunnels to cross the city centre.
In the other direction,
interurban streetcars provided rapid transit-style transit from cities to suburbs and other cities, running mainly on separate
rights-of-way track (sometimes sharing tracks with
intercity rail), but using
streetcar equipment. Most interurbans have been abandoned, but some (like the
Norristown High Speed Line near
Philadelphia) have been reconstructed to rapid transit specifications.
Additionally, many streetcar/tram systems include underground and (less commonly) elevated sections, in which everything about the system except the right-of-way is built to streetcar standards. Notably, the first subway in the
United States,
Boston's
Green Line, opened in
1897 to take streetcars off downtown streets, though it did carry elevated trains from
1901 until the
Washington Street Tunnel opened. Likewise,
San Francisco's
Market Street Subway carries
Muni Metro light rail on the upper tracks and
Bay Area Rapid Transit metro trains on the lower level.
The coming of modern
light rail in the
1970s brought new crossovers. New systems were built and old streetcar/tram systems were upgraded with higher capacity and speeds, but retaining some aspects of streetcars and trams. Some systems known as ''light rail'', such as the
Docklands Light Railway in
London,
Manchester Metrolink,
Edmonton LRT, and
New York City's
AirTrain JFK, are indeed rapid transit systems but commonly described as light rail. In many Asian countries ''light rail'' also is generally used to refer to some sort of rapid transit system but not used to refer to street cars or trams. Other light-rail systems may use high platforms but otherwise run as streetcars. A few systems similar to
interurban streetcars have come back, such as
New Jersey's
River Line, which operates over freight rails for most of its trip, and along streets on one end. The
KCR Light Rail, which runs as streetcars, operates with high platforms, with some of its sections elevated or street level right-of-way, and some at ground-level by away from streets.
Importance and functions
The volume of passengers a metro train can carry is often quite high, and a metro system is often viewed as the
backbone of a large city's public transportation system. In many cities passengers beginning their journeys on a streetcar/tram, bus, or suburban rail system must finish their journey into the city center on the metro, as their first
mode of transport will terminate at a metro station to avoid congesting the city center above ground.
Budapest is a perfect example where the two more modern metro lines connect with feeder buses and trams and also with two circular streetcar/tram routes (one closer to and one further from the city center) that allow travel between suburbs and also into the centre of the city by changing onto the metro.
In some cities, the urban rail system is so comprehensive and efficient that the majority of city residents use it as their primary means of transport.
Berlin,
Hong Kong,
London,
Madrid,
Moscow,
New York City,
Paris,
Seoul and
Tokyo are such examples; these cities have the most extensive and convenient metro systems in the world. With 15 lines, the
Tokyo subway is the largest rapid transit network in the world, transporting 7 million passengers daily.
[19] The majority of suburban residents in addition to city dwellers do not own automobiles and depend on rail as the primary means of travel.
Osaka, Japan is similar to Tokyo's system except about half as large, but still has a ridership exceeding that of New York City.
In Europe, London (in 1st place) and Madrid (second) have the largest metro systems. The busiest metro system in Europe is Moscow, followed by Paris.
Due to a general low population density and a different urban plan, many cities in the
United States have very low rates of transit usage. About one in every three users of mass transit in the United States and two-thirds of the nation's rail riders live in New York
[20] (see
Transportation in New York City). Cities like
Chicago,
Boston,
Washington, D.C., and
Philadelphia also have high ridership on their networks. But other cities in the U.S. where automobiles dominate transportation needs tend to have partial and/or poorly used systems, especially in
sunbelt cities such as
Phoenix,
Los Angeles,
Atlanta,
Charlotte,
Dallas,
Las Vegas or
Houston.
[21]
Alternate uses
Most underground systems are for public transportation, but a few cities have built freight or
postal lines. One example was the
Post Office Railway, which transported mail underground between sorting offices in
London from
1927 until it was abandoned in
2003.
[22] Similarly, until the 1970s the
London Underground's Circle Line (originally the Metropolitan Railway) transported goods as well as running passenger trains. Another example was the
Chicago Tunnel Company, which had a dense grid of tunnels under downtown
Chicago.
[23] During the
Cold War an important secondary function of some underground systems was to provide shelter in case of a nuclear attack. For example, St-Petersburg and Moscow metro systems include a large number of hidden public shelters with water supply and air filtering facilities, military dormitories and bathrooms which currently belong to the Civil Defence Staff. Additionally, Russian and Soviet metros in federal cities are used for governmental telephone systems. Thus in Russia and Soviet Union subways are considered military objects and taking photographs there is prohibited.
Stations
Main articles: Metro station
Urban rail systems have often been used to showcase economic, social, and technological achievements of a nation, especially in the
Soviet Union and other Eastern European countries. With their marble walls, polished granite floors and splendid mosaics, the metro systems of
Moscow and
St. Petersburg are widely regarded as some of the most beautiful in the world. Modern metro stations in
Russia are usually still built with the same emphasis on appearance. In the former Soviet Union and in Eastern Europe metro stations were seen as a way to get art out to the public, instead of containing it for the rich. This is also part of the reason of the use of more classical art and architecture instead of the more modern, streamlined style used in the West. A lot of metros built in the USSR and Eastern European countries use quite expensive materials in the construction of the stations.
[24]
But the art also has a practical purpose, in addition to the pure aesthetic. Beautified metro systems show higher passenger numbers than other, more plain systems. A lot of cities, faced with
congestion problems, are investing large amounts of money in public transport to decrease
car use, and are faced with problems encouraging increased use of rapid transit without large
capital investment or operating costs. By using relatively small amounts on grand
architecture,
art,
cleanliness,
accessibility,
lighting and a feeling of
safety, metros can get larger amounts of passengers; usually the extra investments in
aesthetics are profitable for the metros.
[25] An example of this is in
Los Angeles where 0.5% of investments were used on art while in
Stockholm the authorities publish a
guide to the art in the stations.
[24]
Technology
Main articles: Rapid transit technology
Most rapid transit trains are
electric multiple units. Power is commonly delivered by a
third rail, or in systems without much length in tunnel, by
overhead wires, for example the
Tyne and Wear Metro in North East England. Most run on conventional steel railway tracks, although some use
rubber tires such as the
Montreal system, which relies on rubber tires to soften the effects of vibration (as the train cars are narrow) while using steel tracks to provide guidance. Crew sizes have decreased throughout history, with some modern systems now running completely unstaffed trains.
The method of
tunnel construction used varies from place to place, depending on the situation.
Cut-and-cover tunnels are constructed by digging up city streets, which are then rebuilt over the tunnel. Alternatively,
tunnel-boring machines can be used to dig deep-bore tunnels.
History
Main articles: History of Rapid transit
The first underground railway in the world was the
London Underground.
[27] London's system was proposed by Charles Pearson, as part of a city improvement plan, after the Thames Tunnel opened. After ten years of discussion, the British Parliament authorized the construction of an underground railway. Construction began in
1860 and was complete in
1863. The first trains that ran were
steam locomotives.
[28]
The first rapid transit systems in
North America were
elevated railways like
Manhattan's
Ninth Avenue Line (1868). The first underground transit line was a short piece of
Boston's
Green Line, opened in 1897, but this was a
streetcar tunnel that only carried rapid transit trains from 1901 to 1908 (when Boston's first new rapid transit tunnel opened).
In
Buenos Aires Argentina,
Line A, which opened to the public in 1913, is the oldest underground line of South America and of any Hispanic country and currently, its historic cars are still in use.
Maps and diagrams
Main articles: urban rail and metro maps
The maps of diagrams of some of the larger rapid transit systems have themselves become cultural icons with artworks, books, websites, films and TV programmes revolving round them. The most well-known of all is the
London Underground Map, but the maps of the
New York Subway, The
Paris Metro,
Chicago CTA,
Berlin U-Bahn (among others) receiving some of the most attention in the form of
clothing (
underwear,
T-Shirts &
ties seem especially popular);
board games and
puzzles;
stationery and
mousemats; shower curtains; tea-towels;
fan sites;
blogs;
works of art; official copies and contentious infringements of
copyright.
See also
★
All-four
★
Bus rapid transit
★
Light rail
★
List of rapid transit systems
★
Metrophile (A person with a devoted interest in these systems).
★
Monorail
★
Public transport
★
Rubber-tired metro
★
S-Bahn
★
Tram
★
Transit fares
★
U-Bahn
★
Urban rail transit
References
1. London, England, United Kingdom, , , , National Geographic,
2. 'Subway', 'World Book' ISBN 0-7166-0104-4
3. World Metro List
4. FAQ
5. The American Heritage Dictionary of the English Language, Fourth Edition, , , , Houghton Mifflin Company, , ISBN 0-618-08230-1
6. Definition of "Underground"
7. Lokaltog, T-banen, Trikken
8. Setp_sys_Route_Map.pdf
9. Docklands Light Railway - About DLR
10. Bangkok Mass Transit System Company Limited - BTS SkyTrain
11. MARTA - About MARTA
12. AirTrain History
13. Las Vegas Monorail - History
14. UrbanRail.Net > Métro de PARIS
15. BART Strategic Plan San Francisco Bay Area Rapid Transit District
16. Tyne & Wear Metro
17. Olympic Games 2004: five major projects for Athens
18. Hong Kong West Rail Heavy Rail Line, China
19. Tokyo transportation fact sheet
20. MTA - Transportation Network
21. Heavy Rail Transit Ridership Report American Public Transport Assosiation
22. Rail Mail Home
23. The Chicago Tunnel Company Railroad Home Page
24. Metro Arts and Architecture
25. 10 Ways to Enhance Your Community: Unleash the Power of Public Transportation
26. Metro Arts and Architecture
27. History - Introduction
28. Subway Encyclopædia Britannica online
External links
★
UrbanRail.Net (formerly called metroPlanet) – descriptions of all metro systems in the world, each with a schematic map showing all stations.
★
Monorail Society A group of monorail enthusiasts. Website has extensive resources: technical information, manufacturers, photographs, reports on current monorail systems around the world.
★
New York City Subway Resources, an extensive site that includes many photos and much information about rapid transit systems in the U.S. and worldwide, in addition to New York City.
★
rapidtransit.com, which includes links to operating companies
★
Undistorted metro network maps, all at the same scale for comparison.
★
More undistorted maps, for all of the systems of North America.
★
Metro Bits Various aspects of the world's metros.
★
NAUTF | North American Urban Transit Forum
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