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Personal rapid transit (PRT), also called podcar, is a public transport mode featuring small automated vehicles operating on a network of specially built guideways. PRT is a type of automated guideway transit (AGT), a class of system which also includes larger vehicles all the way to small subway systems. PRT vehicles are sized for individual or small group travel, typically carrying no more than 3 to 6 passengers per vehicle. Guideways are arranged in a network topology, with all stations located on sidings, and with frequent merge/diverge points. This allows for nonstop, point-to-point travel, bypassing all intermediate stations. The point-to-point service has been compared to a taxi or a horizontal lift (elevator). As of July 2013, four PRT systems are operational: The world's oldest and most extensive PRT system is in Morgantown, West Virginia. It has been in continuous operation since 1975. Colloquially known merely as 'the PRT,' West Virginia University's system moves student and visitors alike to a number of popular destinations throughout the city. Since 2010 a 10-vehicle 2getthere system has operated at Masdar City, UAE, and since 2011 a 21-vehicle Ultra PRT system has run at London Heathrow Airport. A 40-vehicle Vectus system with in-line stations officially opened in Suncheon, South Korea, in April 2014 after a year of testing.〔Masdar City and Suncheon have only two passenger stations while at Heathrow the two stations at the carpark are very close to one another. Masdar also has three freight stations.〕 Expansion of the Masdar system was cancelled just after the pilot scheme opened. Numerous other PRT systems have been proposed but not implemented, including many substantially larger than those now operating. ==Overview== Most mass transit systems move people in groups over scheduled routes. This has inherent inefficiencies.〔(【引用サイトリンク】title=An Intelligent Transportation Network System: Rationale, Attributes, Status, Economics, Benefits, and Courses of Study for Engineers and Planners )〕 For passengers, time is wasted by waiting for the next arrival, indirect routes to their destination, stopping for passengers with other destinations, and often confusing or inconsistent schedules. Slowing and accelerating large weights can undermine public transport's benefit to the environment while slowing other traffic.〔 Personal rapid transit systems attempt to eliminate these wastes by moving small groups nonstop in automated vehicles on fixed tracks. Passengers can ideally board a pod immediately upon arriving at a station, and can — with a sufficiently extensive network of tracks — take relatively direct routes to their destination without stops.〔 Perhaps most importantly, PRT systems offer many traits similar to automobiles. For example, they offer privacy and the ability to choose one's own schedule.〔 PRT may in fact allow for quicker transportation than cars during rush hour, since automated vehicles avoid unnecessary slowing. A PRT system can also transport freight. The low weight of PRT's small vehicles allows smaller guideways and support structures than mass transit systems like light rail.〔 The smaller structures translate into lower construction costs, smaller easements, and less visually obtrusive infrastructure.〔 As it stands, a city-wide deployment with many lines and closely spaced stations, as envisioned by proponents, has yet to be constructed. Past projects have failed because of financing, cost overruns, regulatory conflicts, political issues, misapplied technology, and flaws in design, engineering or review.〔 However, the theory remains active. For example, from 2002–2005, the EDICT project, sponsored by the European Union, conducted a study on the feasibility of PRT in four European cities. The study involved 12 research organizations, and concluded that PRT:〔(Moving ahead with PRT ) from ec.europa.eu〕 * would provide future cities "a highly accessible, user-responsive, environmentally friendly transport system which offers a sustainable and economic solution." * could "cover its operating costs, and provide a return which could pay for most, if not all, of its capital costs." * would provide "a level of service which is superior to that available from conventional public transport." * would be "well received by the public, both public transport and car users." The report also concluded that, despite these advantages, public authorities will not commit to building PRT because of the risks associated with being the first public implementation.〔〔(EDICT Final Report (PDF)" ) from cardiff.gov.uk〕 The PRT acronym was introduced formally in 1978 by J. Edward Anderson.〔J. Edward Anderson, ("What is Personal Rapid Transit?" ), University of Washington, 1978〕 The Advanced Transit Association (ATRA), a group which advocates the use of technological solutions to transit problems, compiled a definition in 1988 that can be seen here.〔(【引用サイトリンク】title=PRT Background )〕 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Personal rapid transit」の詳細全文を読む スポンサード リンク
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