Urban rail transit
Urban rail transit is an all-encompassing term for various types of local rail systems providing passenger service within and around urban or suburban areas. The set of urban rail systems can be roughly subdivided into the following categories, which sometimes overlap because some systems or lines have aspects of each.
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[edit] Urban rail transit types
[edit] Tram
A tram, streetcar or trolley system is a rail-based transit system that runs mainly or completely along streets, with relatively low capacity and frequent stops. Passengers usually board at street- or curb-level, although low-floor trams may allow level boarding. Longer-distance lines are called interurbans or radial railways. Few interurbans remain, most having been upgraded to commuter rail or abandoned .
The term "tram" is used most parts of the world. In North America, these systems are referred to as "streetcar" or "trolley" systems.
[edit] Light rail
A Light rail system is a rail-based transit system that has higher capacity and speed than a tram, but is not fully grade-separated like rapid transit. It emerged as an outgrowth of trams/streetcars. Light rail systems vary significantly in terms of speed and capacity. They range from slightly improved tram systems to systems that are essentially rapid transit with level crossings.
The term "light rail" is the most common term used, though German systems are called "Stadtbahn" (City Rail).
[edit] Rapid transit
A rapid transit, underground, subway, tube, elevated, or metro 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" which is short for "metropolitan". The term "subway" is used in many American systems as well as in Glasgow and Toronto. The system in London uses the terms "underground" and "tube". Systems in Germany are called "U-Bahn", which stands for "Untergrundbahn" (underground way). Many systems in East and Southeast Asia such as Taipei and Singapore are called MRT which stands for Mass Rapid Transit. Systems which are predominantly elevated may be referred to as "L" as in Chicago or "Skytrain", as in Bangkok and Vancouver. Other less common names include "MTR" and "T-bane".
[edit] Monorail
A Monorail is a metro with a track consisting of a single rail, as opposed to the traditional track with two parallel rails.
[edit] Commuter Rail
A commuter rail or regional rail system operates on mainline trackage which may be shared with intercity rail and freight trains. Systems tend to operate at lower frequencies than rapid transit systems, but tend travel at higher speeds and cover longer distances. Though many European and East Asian commuter rail systems operate with frequencies and rolling stock similar to that of rapid transit, they do not qualify as such because they share tracks with intercity trains.
[edit] Funicular
A Funicular is a cable-driven inclined railway that uses the weight of descending cars to help pull the ascending cars up the slope.
[edit] Classification Issues
Transit agencies' names for lines do not necessarily reflect their technical categorization. For example, Boston's Green Line is referred to as a subway, despite having street-running portions. Conversely, the Docklands Light Railway in London, Green Line in Los Angeles and some metro lines in China are referred to as "Light Rail" even though they qualify as rapid transit because they are fully grade-separated and provide a high frequency of service.
Many cities use names such as subway and elevated railway to describe their entire systems, even when they combine both methods of operation. Slightly less than half of the London Underground's tracks, for example, are actually underground; New York City's subway also combines elevated and subterranean stations, while the Chicago 'L' and Vancouver SkyTrain use tunnels to run through central areas.
[edit] Other types of services
[edit] Bus
A bus shares many characteristics with light rail and trams, but does not run on rails. Trolleybuses are buses that are powered from overhead wires. Vehicles that can travel both on rails and on roads, have been tried experimentally, but are not in common use. The term bus rapid transit is used to refer to various methods of providing faster bus services and the systems which use it have similar characteristics to light rail. Some cities experimenting with guided bus technologies, such as Nancy, have chosen to refer to them as 'trams on tyres' (rubber tyred trams) and given them tram-like appearances.
[edit] Economics of rail transit
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The examples and perspective in this article may not represent a worldwide view of the subject. Please improve this article and discuss the issue on the talk page. (December 2010) |
It is true that public rail transit provides certain benefits for a community. Economists encourage people, in addition to observing benefits, to consider the costs of urban transit as well. They agree the goals of policymakers in this situation are not often met. Some American economists claim that, contrary to popular belief, rail transit has failed to improve the environment, serve the poor, or reduce highway congestion in the United States. Economists, however, are somewhat more optimistic about rail transit's impact on economic development. But as more suburbanization occurs, central business districts decline, and people acquire more wealth a successful rail transit system might become harder to achieve in the future.[1]
According to one analysis, nine out of ten urban rail projects experience cost overrun. The average overrun was 45 percent, measured in constant prices from decision to build to project completion.[2]
[edit] See also
- List of rail transit systems in North America
- List of rail transit systems in the United States
- List of rail transit systems by type
- Passenger rail terminology
[edit] References
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This article needs additional citations for verification. Please help improve this article by adding citations to reliable sources. Unsourced material may be challenged and removed. (July 2010) |
- Flyvbjerg, B. "Cost Overruns and Demand Shortfalls in Urban Rail and Other Infrastructure," Transportation Planning and Technology, vol. 30, no. 1, February 2007, pp. 9-30.
- 1- Balaker, Ted and Cecilia Juong Kim. "Do Economists Reach a Conclusion On Rail Transit?" (Sept 2006). [2]
[edit] Further reading
- "Electric Railway Transportation," Annals of the American Academy of Political and Social Science Vol. 37, No. 1, Jan., 1911 pp1-202 online 17 articles by experts in 1911.
