Promotional billboard indicating the original seven proposed LRT lines

Transit City was a plan for developing public transport in Toronto, Ontario, Canada. It was first proposed and announced by then-Toronto Mayor David Miller and Chair of the Toronto Transit Commission (TTC) Adam Giambrone on March 16, 2007. The plan called for the construction of seven new light rail lines along the streets of seven priority transit corridors, which will eventually be integrated with existing rapid transit, streetcar, and bus routes.^[1] Other transit improvements outlined in the plan included upgrading and extending the Scarborough RT line, implementing new bus rapid transit lines, and improving frequency and timing of 21 key bus routes.^[2][3][4] The plan integrated public transportation objectives outlined in the City of Toronto Official Plan, the TTC Ridership Growth Strategy and Miller's 2006 election platform.

Since the official announcement of the plan, preliminary engineering work and environmental impact assessments were done for the construction of the light rail lines.^[5] Public meetings have been held to generate community discussion. The plan was initially reported to be funded by both municipal and provincial levels of government. However, as the Government of Ontario later decided to postpone a portion of its capital funding to Transit City, which met with much public and political controversy, construction plans were changed causing longer delays in construction start dates. Construction of one of the lines began in December 2009.

On December 1, 2010, Rob Ford, who was elected mayor in the 2010 municipal election, took office saying that the first job of the new transit commission to be appointed on December 8 would be to "stop spending money on a project we don't need anymore". Ford campaigned on a platform proposing expansion of the subway system, instead of implementing light rail lines. Ford acknowledged that he will need council's support to put an end to Transit City.^[6] In early 2012, Toronto City Council voted in favour of motions to resume work on the Sheppard, Eglinton and Finch LRT lines, as well as replacing the Scarborough RT, defeating Rob Ford's campaign for subways.^[7][8] While these projects were originally proposed under Transit City, they have instead been referred to as being part of the Metrolinx "5 in 10" plan.^[9]

Projects[link]

The plan originally proposed 120 km (74.6 mi) of tram or electric light rail along seven routes. The proposed network would carry 175 million riders a year, of which 75 million would be new TTC users.^[10] The seven proposed corridors have been divided into two project priority phases: current and planned. The Metrolinx CEO, Robert Prichard recently announced that after further study, the proposed project was being scaled down, with shortened routes or deferrals to fit within the dedicated provincial funding for Transit City, not factoring in the province's March 2010 announcement that it was deferring $4 billion in funding.^[10]

The Toronto Transit Commission (TTC) was prepared to fund the entire cost of the network over a longer period of time. The highest priority was assigned to the Sheppard East, Eglinton Crosstown LRT and Etobicoke-Finch West LRT lines, as well as the revitalization of the Scarborough RT line, which was projected to be built by 2020. In addition to the mentioned lines, it was likely that some sort of link would be established between the two lines, so that they could share a single storage facility. The TTC completed the environmental impact assessments for most of these lines, the first one being completed for the Sheppard East line.^[11] The construction of this line commenced on December 2009 and is expected to be complete in 2013.^[12]

Light rail transit[link]

The following routes were to be constructed and opened by 2020. Development on the Scarborough RT line was also considered to be priority (see below).

• Sheppard East LRT: This line would run along Sheppard Avenue East from Don Mills Station via the future Sheppard East RT station on the Scarborough RT line, ending at a planned storage facility at Conlins Road, just east of Morningside Avenue. Initially, the line was to be constructed approx. 5 km further east to as far as Meadowvale Road, but that portion will be postponed as a result of the provincial funding cuts.^[13] Construction for the line began in December 2009 with official groundbreaking by Toronto Mayor David Miller. The line will be serving the Sheppard East Village, a commercial neighbourhood along Sheppard Avenue East. An extension of the line northwards to the Toronto Zoo is being considered. Under construction since 2009, the line was expected to be completed and opened in 2014, the first of the seven lines.

• Etobicoke-Finch West LRT: One running along Finch Avenue West, from Humber College North Campus to the future Finch West subway station on the Yonge–University–Spadina subway. Initially, the plan was to keep the line's eastern terminus at Finch subway station and later extend the line to Don Mills subway station, providing a continuous route with the Sheppard East LRT, but has been postponed as a result of provincial funding cuts. Construction for its current route was expected to be completed by 2019.

• Eglinton Crosstown LRT: The longest proposed corridor, at over 30 km (18.6 mi), would be along Eglinton Avenue, from Kennedy subway station in Scarborough to Jane Street. The line was initially proposed to be continue further west to Toronto Pearson International Airport, but that portion has been postponed as a result of provincial funding cuts. Between Keele Street and Laird Drive, the road has been deemed too narrow for a right-of-way, and therefore the line will run in a tunnel (with underground stations), much like the cancelled Eglinton West subway line.^[13] The currently planned route is expected to be constructed by 2020. It is the only LRT line that survived Rob Ford's cuts, albeit modified to include an extended underground section in the eastern section and the removal of the western section. The eastern underground extension was later revised back to a surface alignment in the 2012 transit vote; the western segment remains in question depending on future funding.

The following projects are currently undergoing environmental assessments and construction were to begin after 2020 and be completed by 2030 at the latest:

• Jane LRT: One running along Jane Street, from Steeles West Station on the Yonge-University-Spadina subway line (east of the Jane/Steeles intersection), connecting with the Bloor–Danforth subway at (presumably) Jane Station. This line was likely be tunnelled for about 2 km from St. Clair Avenue to Bloor Street.^[13]

• Don Mills LRT: One running along Don Mills Road from Steeles Avenue, then through Don Mills station, then through East York Centre (Overlea Boulevard), where it would then follow the Leaside Bridge to Pape Avenue, and tunnel under Pape for about 2 km to Danforth (presumably at Pape Station).^[13]

• Waterfront West LRT: One along the western waterfront. This line would run along Lake Shore Boulevard West from Long Branch GO Station eastward to the Exhibition Grounds, where it would continue eastwards along Fort York Boulevard and Bremner Street toward Union station. This route was proposed since it passes by some densely built upcoming neighbourhoods and trip generators such as the Rogers Centre and the CN Tower.^[13][14]

• Scarborough Malvern LRT: One running from Kennedy Station to the Morningside/Sheppard intersection near the Malvern neighbourhood via Eglinton Avenue East, Kingston Road and Morningside Avenue. The line would pass near the University of Toronto Scarborough (UTSC);^[13] and with Toronto being the host of the 2015 Pan American Games, it was previously believed that this line may commence much sooner since UTSC will be one of the venues of the games.^[15]

Scarborough RT[link]

Part of the Transit City project is the revitalization of the existing Scarborough RT rapid transit line. This project will extend the existing line eastwards from its present terminus at McCowan Station to three additional stops. The first proposed station will be at Bellamy Road to serve the Consilium Place business area and the second on Progress Avenue, east of Markham Road, serving Centennial College Progress Campus. The line will then curve north to Sheppard Avenue East, connecting with the Sheppard East LRT. A new environmental class assessment is being made to further continue the line north into the neighbourhood of Malvern over a former railbed just east of Markham Road. In the future, an in-fill station may be added at Brimley Road.

The existing service is approaching the end of the operational life of its ICTS fleet; as trains are no longer built to that line's specification, a replacement is needed. While an upgraded form of ICTS (Mark II Vehicles designed by Bombardier) had been considered, the current recommendation is to implement the LRT/tram technology used for Transit City to save on the fleet and track maintenance costs currently incurred by this unique-within-Toronto system. All renovations and extension constructions are to be completed by 2020. However, under Rob Ford, the renovated and extended Scarborough RT will become a part of the Eglinton Crosstown LRT instead and renamed Eglinton–Scarborough Crosstown line.

Bus rapid transit[link]

The TTC was also planning to begin six new bus rapid transit (BRT) right-of-way lines once the tramline or light rail transit construction was complete, some of which are temporary until a subway extension occurs while one of them is already in service. The proposed routes are:

• along Ellesmere Road, from Scarborough Centre station to the Durham Region.
• along Danforth Avenue and Kingston Road from Victoria Park station to the Kingston Road/Eglinton Avenue intersection, where a station will be built connecting to the future Scarborough Malvern LRT line.
• along Dundas Street, from Kipling station to Mississauga.
• along Wilson Avenue, from Wilson Station to Keele Street.
• along Yonge Street from Finch station to Richmond Hill.
• York University Busway, connecting Downsview station to York University, which began service in 2009.

The York University Busway may stop service once the Spadina subway extension to Vaughan Metropolitan Centre station is complete. Likewise, creating a BRT line on Yonge Street depends on the fate of the proposed Yonge subway extension; if the subway extension is not approved, then work on the BRT line may commence.

Funding and costs[link]

In April 2009, Finch West, Eglinton Crosstown, and the Scarborough RT upgrade and extension secured $7.2 billion in funding from the province,^[16] while the Sheppard East LRT has received $613 million in funding from the province, and $317 million in federal funding.^[17] In November 2007, the TTC provided an updated estimate of the costs of the proposal in its capital budget.^[18] The project cost to be paid by the Government of Ontario is $8.3 billion.

On June 15, 2007, the Government of Ontario announced its MoveOntario 2020 plan, that calls for a major overhaul and expansion of the Greater Toronto Area's transit systems, including the Transit City proposal, that will cost an estimated $17.5 billion in provincial and federal funding over a 12-year period.^[19] The provincial government proposes to provide two-thirds of the funds ($11.5 billion), and will ask the federal government to pay the remaining one-third ($6 billion).^[19] However, Prime Minister Stephen Harper's government is currently not committed to this spending plan.^[19] The province's $17.5 billion MoveOntario 2020 plan calls for a total number of 52 transit projects in the GTA to be funded, with 95% of the projects completed by the year 2020.^[20]

Controversy[link]

On March 25, 2010, the Ontario provincial government announced their decision to postpone $4 billion of funding to Metrolinx for the MoveOntario 2020 project, which included funding for Transit City. Toronto Mayor David Miller had expressed discontent and condemned Ontario Premier Dalton McGuinty, who had earlier promised to provide full funding for Transit City in order for it to be built before the 2015 Pan American Games in Toronto.

The initial investment was to create approximately 100,000 jobs.^[21][22] The stated reason for the decision is a $21.3 billion deficit in the 2010 provincial operating budget.^[23] Standard economic metrics, however, show that as stimulus, Transit City adds significantly to provincial tax revenues, and given the province's 50-year amortization, the plan overall reduces Ontario's annual budget deficit.^[24] This caused widespread debate, protests and criticism of premier Dalton McGuinty by politicians and local groups. As a result of the postponement, the plan has since been scaled down and expected completion dates have been further pushed back.^[25]

The delay in funding, according to Miller, meant that the priority LRT lines (Scarborough RT, Etobicoke-Finch West and Eglinton Crosstown) would not be able to meet their planned construction and opening dates; work on the Sheppard East line would proceed, however, as its construction had already begun.^[26] Despite the controversy over the funding, Metrolinx had still negotiated a deal with Bombardier Transportation for a new fleet of trams or light rail vehicles which would be used on future Transit City lines.^[27]

Since the announcement, the City of Toronto and community groups have begun a lobbying campaign to restore funding, similar to the campaign leading to the initial funding. Mayor Miller has condemned the funding delay and requested riders to contact their Members of Provincial Parliament to have the government restore the funding. Other Transit City advocates also petitioned and organized rallies to promote the immediate construction of the projects.^[28]

The Public Transit Coalition was launched by common transit riders to counter the delay in Transit City funding. On April 21, 2010, the group held an event at the Toronto City Hall Council Chambers.^[29]

Economic effect[link]

Transit City was expected to create approximately 200,000 new jobs in Ontario from $8.3 billion invested.^[30] This includes operation, construction, and economic stimulus effect of spending. Unemployment reached 9% in 2010, the GTA's highest level since 1995.^[31]

The Ontario government's promised funding for Transit City creates short-term economic growth of $12.4 billion per year,^[32] adding in the near-term 2.1% to Ontario's GDP, according to the American Public Transportation Association.^[33]

According to the Federation of Canadian Municipalities research, Transit City was to produce a first-year GDP gain of $17.3 billion, were all the money to be spent in the first year. After five years the project levels off to add $8.0 billion per year to GDP, with each $1 billion spent on transit adding 0.06% to Canada's GDP annually. This compares closely to US Congressional testimony, which shows infrastructure investment to stimulate annual GDP at a multiplier of 1.69 within one year, or $14 billion per year for Transit City.^[34] Both studies count direct impact of spending only.^[35]

In addition to this direct consequence, long-term indirect effects on business costs, productivity, and consumer spending from reduced congestion and travel costs create an additional $14.1 billion of value annually to Ontario's economy.^[30] Other indirect effects not measured are improved air quality and public health and reduced carbon emissions from extending rapid transit to 1.1 million more people.

Ontario taxes capture 12% of Ontario's GDP, meaning that Transit City's stimulus effect directly adds to Provincial tax revenue.^[36][37] Transit City's direct economic impact of $12.4 billion per year nets the Ontario treasury $1.4 billion in annual tax revenue. Indirect effects on congestion and transportation costs produce an additional $1.7 billion per year in tax revenue. Government of Canada Bonds currently offer 4% interest for a 10 year term.^[37] Transit City's $8.3 billion expansion funding, if amortized over 10 years at prevailing bond rates, cost the Province $1.2 billion per year.^[38] With Provincial tax revenues of $3.1 billion per year, Transit City easily makes up its financing cost.

Criticism[link]

In December 2010, Rob Ford, who succeeded David Miller as mayor, announced his intention to cancel key parts of Transit City, saying "we will not build any more rail tracks down the middle of our streets." However, he was open to the Eglinton Crosstown LRT, given that it is primarily underground.^[39]

The proposed Eglinton Crosstown line merged with the existing Scarborough RT to become the Eglinton–Scarborough Crosstown line.

See also[link]

• Toronto streetcar system
• Toronto subway and RT
• Downtown Relief Line

References[link]

External links[link]

• Official website
• City of Toronto Transit City Project Website

v t e Toronto Transit Commission Buses Blue Night Network Fleet Routes Wheel-Trans York University Busway Subway/RT      Bloor–Danforth      Scarborough RT      Sheppard      Yonge–University–Spadina Rolling stock Stations Signals Streetcar 501 Queen 502 Downtowner 503 Kingston Rd 504 King 505 Dundas 506 Carlton 508 Lake Shore 509 Harbourfront 510 Spadina 511 Bathurst 512 St. Clair Rolling stock Loops Light rail Sheppard East Finch West Eglinton–Scarborough Crosstown Facilities Arrow Road Bus Garage Ashbridges Bay Carhouse Birchmount Bus Garage Davisville Subway Yard Eglinton Bus Garage Greenwood Subway Yard Hillcrest Complex Lakeshore Bus Garage Malvern Bus Garage McCowan RT Yard Mount Dennis Bus Garage Queensway Bus Garage Roncesvalles Carhouse Russell Carhouse Toronto Coach Terminal Vincent Subway Yard Wilson Bus Garage and Subway Yard William McBrien Building History Williams Omnibus Bus Line Toronto Street Railway Toronto Suburban Railway Toronto Railway Toronto Civic Railways Toronto Transportation Commission Toronto Island Ferry Gray Coach Queen line Municipal Service Car Network 2011 Downtown Relief Line 1995 Russell Hill subway accident Eglinton West line 2006 wildcat strike 2008 strike Transit City Special Constable Services Miscellaneous Accessibility Communications and Information System Fares Metrolinx Obay Personnel Toronto Subway Font Italics indicate a proposed route or project under construction

An ULTra PRT vehicle on a test track.

A vehicle on WVU's Morgantown Personal Rapid Transit.

Personal rapid transit (PRT), also called podcar, is a public transportation mode featuring small automated vehicles operating on a network of specially built guide ways. 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.

In PRT designs, vehicles are sized for individual or small group travel, typically carrying no more than 3 to 6 passengers per vehicle.^[1] Guide ways are arranged in a network topology, with all stations located on sidings, and with frequent merge/diverge points. This approach 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).

PRT was a major area of study in the 1960s and 1970s. In 1975, Morgantown PRT, an experimental automated system which exhibits some (but not all) features of PRT, was opened to the public after significant construction cost overruns. Morgantown PRT remains in use today, and there have been discussions on expanding it.^[2]

A PRT system (by 2getthere) went into operation in Masdar City in the UAE in November 2010. The system has 10 passenger and 3 freight vehicles serving 2 passenger and 3 freight stations connected by 1.2 kilometers of one-way track. The system is in operation 18 hours a day, seven days a week serving the Masdar Institute of Science and Technology. Trips take about 2 and a half minutes (i.e., an average speed of roughly 12mph / 20km/h) and are presently free of charge. Average wait times are expected to be about 30 seconds.

The award winning ULTra PRT system began passenger trials at London Heathrow Airport, Terminal 5, in October 2010^[3] and opened for full passenger service 22 hours a day, 7 days a week, in May 2011. It runs between the Terminal 5 and its business parking lot, with 2.4 miles of track and 21 vehicles. Operational statistics in May 2012 demonstrate >99% reliability and an average passenger wait time over the one year period of 10 seconds. Ultra has achieved a number of awards from the London Transport Awards and the British Parking Awards.^[4][5]

A system using a system supplied by Vectus is in construction in Suncheon, South Korea. There is a commitment to a large (100,000 people per day) City PRT system using Ultra PRT technology in Amritsar, India.^{[citation needed]}

Overview[link]

Most mass transit systems move people in groups over scheduled routes. This has inherent inefficiencies.^[6] 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.^[6] 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.^[6]

Perhaps most importantly, PRT systems offer many traits similar to cars. For example, they offer privacy and the ability to choose one's own schedule.^[6] 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.^[6] The smaller structures translate into lower construction cost, smaller easements, and less visually obtrusive infrastructure.^[6]

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.^[6]

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:^[7]

• would provide future cities "a highly accessible, user-responsive, environmental 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.^[7][8]

The PRT acronym was introduced formally in 1978 by J. Edward Anderson.^[9] 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.

Existing and planned networks[link]

Currently, two PRT networks and one quasi-PRT network are operational, and several more are in the planning stage.

Designs[link]

The following table summarizes several well-known PRT designs.

• Morgantown PRT is known as a quasi-PRT system, because it lacks some PRT features such as 100% on-demand service.
  

History[link]

Origins[link]

Modern PRT concepts began around 1953 when Donn Fichter, a city transportation planner, began research on PRT and alternative transportation methods. In 1964, Fichter published a book,^[32] which proposed an automated public transit system for areas of medium to low population density. One of the key points made in the book was Fichter's belief that people would not leave their cars in favor of public transit unless the system offered flexibility and end-to-end transit times that were much better than existing systems – flexibility and performance he felt only a PRT system could provide. Several other urban and transit planners also wrote on the topic and some early experimentation followed, but PRT remained relatively unknown.

Around the same time, Edward Haltom was studying monorail systems. Haltom noticed that the time to start and stop a conventional large monorail train, like those of the Wuppertal Schwebebahn, meant that a single line could only support between 20 and 40 vehicles an hour. In order to get reasonable passenger movements on such a system, the trains had to be large enough to carry hundreds of passengers (see headway for a general discussion). This, in turn, demanded large guideways that could support the weight of these large vehicles, driving up capital costs to the point where he considered them unattractive.^[33]

Haltom turned his attention to developing a system that could operate with shorter timings, thereby allowing the individual cars to be smaller while preserving the same overall route capacity. Smaller cars would mean less weight at any given point, which meant smaller and less expensive guideways. To eliminate the backup at stations, the system used "offline" stations that allowed the mainline traffic to bypass the stopped vehicles. He designed the Monocab system using six-passenger cars suspended on wheels from an overhead guideway. Like most suspended systems, it suffered from the problem of difficult switching arrangements. Since the car rode on a rail, switching from one path to another required the rail to be moved; a slow process that limited the possible headways.^[33]

UMTA is formed[link]

By the late 1950s the problems with urban sprawl were becoming evident in the US. When cities improved roads and the transit times were lowered, suburbs developed at ever increasing distances from the city cores, and people moved out of the downtown areas. Lacking pollution control systems, the rapid rise in car ownership and the longer trips to and from work was causing significant air quality problems. Additionally, movement to the suburbs led to a flight of capital from the downtown areas, one cause of the rapid urban decay seen in the US.

Mass transit systems were one way to combat these problems. Yet during this period, the US federal government was feeding the problems by funding the development of the Interstate Highway System, while at the same time funding for mass transit was being rapidly scaled back. Public transit ridership in most cities plummeted.^[34]

In 1962, President John F. Kennedy charged the United States Congress with the task of addressing these problems. These plans came to fruition in 1964, when President Lyndon B. Johnson signed the Urban Mass Transportation Act of 1964 into law, thereby forming the Urban Mass Transportation Administration.^[35] The UMTA was set up to fund mass transit developments in the same fashion that the earlier Federal Aid Highway Act of 1956 had helped create in the Interstate Highways. That is, the UMTA would help cover the capital costs of building out new infrastructure.

PRT research starts[link]

However, planners who were aware of the PRT concept were worried that building more systems based on existing technologies would not help the problem, as Fitcher had earlier noted. Proponents suggested that systems would have to offer the flexibility of a car:

The reason for the sad state of public transit is a very basic one - the transit systems just do not offer a service which will attract people away from their automobiles. Consequently, their patronage comes very largely from those who cannot drive, either because they are too young, too old, or because they are too poor to own and operate an automobile. Look at it from the standpoint of a commuter who lives in a suburb and is trying to get to work in the central business district (CBD). If he is going to go by transit, a typical scenario might be the following: he must first walk to the closest bus stop, let us say a five or ten minute walk, and then he may have to wait up to another ten minutes, possibly in inclement weather, for the bus to arrive. When it arrives, he may have to stand unless he is lucky enough to find a seat. The bus will be caught up in street congestion and move slowly, and it will make many stops completely unrelated to his trip objective. The bus may then let him off at a terminal to a suburban train. Again he must wait, and, after boarding the train, again experience a number of stops on the way to the CBD, and possibly again he may have to stand in the aisle. He will get off at the station most convenient to his destination and possibly have to transfer again onto a distribution system. It is no wonder that in those cities where ample inexpensive parking is available, most of those who can drive do drive.^[36]

In 1966, the United States Department of Housing and Urban Development was asked to "undertake a project to study … new systems of urban transportation that will carry people and goods … speedily, safely, without polluting the air, and in a manner that will contribute to sound city planning". The resulting report was published in 1968,^[37] and proposed the development of PRT, as well as other systems such as dial-a-bus and high-speed interurban links

In the late 1960s, the Aerospace Corporation, an independent non-profit corporation set up by the US Congress, spent substantial time and money on PRT, and performed much of the early theoretical and systems analysis. However, this corporation is not allowed to sell to non-federal government customers. In 1969, members of the study team published the first widely publicized description of PRT in Scientific American.^[38] In 1978 the team also published a book.^[39]

In 1967, aerospace giant Matra started the Aramis project in Paris. After spending about 500 million francs, the project was canceled when it failed its qualification trials in November 1987. The designers tried to make Aramis work like a "virtual train," but control software issues caused cars to bump unacceptably. The project ultimately failed.^[40]

The oil crisis of 1973 made vehicle fuels more expensive, which naturally interested people in alternative transportation.

Between 1970 and 1978, Japan operated a project called Computer-controlled Vehicle System (CVS). In a full-scale test facility, 84 vehicles operated at speeds up to 60 kilometres per hour (37.3 mph) on a 4.8-kilometre (3.0 mi) guideway; one-second headways were achieved during tests. Another version of CVS was in public operation for six months from 1975–1976. This system had 12 single-mode vehicles and four dual-mode vehicles on a 1.6-kilometre (1.0 mi) track with five stations. This version carried over 800,000 passengers. CVS was cancelled when Japan's Ministry of Land, Infrastructure and Transport declared it unsafe under existing rail safety regulations, specifically in respect of braking and headway distances.

On March 23, 1973, U.S. Urban Mass Transportation Administration (UMTA) administrator Frank Herringer testified before Congress: "A DOT program leading to the development of a short, one-half to one-second headway, high-capacity PRT (HCPRT) system will be initiated in fiscal year 1974."^[41] However, this HCPRT program was diverted into a modest technology program.^{[citation needed]} According to PRT supporter J. Edward Anderson, this was "because of heavy lobbying from interests fearful of becoming irrelevant if a genuine PRT program became visible". From that time forward people interested in HCPRT were unable to obtain UMTA research funding.^[42]

In 1975, the Morgantown Personal Rapid Transit project was completed. It has five off-line stations that enable non-stop, individually programmed trips. This is a crucial characteristic of PRT. However, it is not considered a PRT system because its vehicles are too heavy and carry too many people. When it carries many people, it does not operate in a point-to-point fashion, instead running like an automated people mover from one end of the line to the other. Morgantown PRT is still in continuous operation at West Virginia University in Morgantown, West Virginia with about 15,000 riders per day (as of 2003^[update]). It successfully demonstrates automated control, but was not sold to other sites because the steam-heated track has proven too expensive.

From 1969 to 1980, Mannesmann Demag and MBB cooperated to build the Cabinentaxi urban transportation system in Germany. Together the firms formed the Cabintaxi Joint Venture. They created an extensive PRT technology that was considered fully developed by the German Government and its safety authorities. The system was to have been installed in Hamburg, but budget cuts stopped the proposed project before the start of construction. With no other potential projects on the horizon, the joint venture disbanded, and the fully developed PRT technology was never installed. Cabintaxi Corporation, a US-based company obtained the technology in 1985, and remains active in the private-sector market for transportation systems.

In the 1990s, Raytheon invested heavily in a system called PRT 2000, based on technology developed by J. Edward Anderson at the University of Minnesota. Raytheon failed to install a contracted system in Rosemont, Illinois, near Chicago, when estimated costs escalated to US$50 million per mile, allegedly due to design changes that increased the weight and cost of the system relative to Anderson's original design. In 2000, rights to the technology reverted to the University of Minnesota, and were subsequently purchased by Taxi2000.^[43][44]

In 2002, 2getthere operated 25 4-passenger "CyberCabs" at Holland's 2002 Floriade horticultural exhibition. These transported passengers along a track spiraling up to the summit of Big Spotters Hill. The track was approximately 600-metre (1,969 ft) long (one-way) and featured only two stations. The six-month operations were intended to research the public acceptance of PRT-like systems. The CyberCab as designed for the exhibition was very open. It was comparable to a Neighborhood electric vehicle, except it steered itself using magnetic guidance points embedded in the pavement.

Ford Research proposed a dual-mode system called PRISM.^[45] It would use public guideways with privately purchased but certified dual-mode vehicles. The vehicles would weigh less than 600 kg (1,323 lb). Most energy use occurs on highways, so small, elevated guideways would inductively power highway use and recharge batteries for off-guideway use. Central computers could do routing.

In January 2003, the prototype ULTra ("Urban Light Transport") system in Cardiff, Wales, was certified to carry passengers by the UK Railway Inspectorate on a 1 km (0.6 mi) test track. ULTra was selected in October 2005 by BAA plc for London's Heathrow Airport.^[46] As of September 2011, a pilot system of the Heathrow PRT is fully operational, transporting passengers from a remote parking lot to the central terminal area. Further plans call for expansion throughout the airport and the surrounding region, pending the results of the pilot phase.^[19]

In June 2006, a Korean/Swedish consortium, Vectus Ltd, started constructing a 400-metre (1,312 ft) test track in Uppsala, Sweden.^[47] This test system was presented at the 2007 PodCar City conference in Uppsala, Sweden.^[48]

The Vectus project was based on The Fornebu/Oslo PRT Project. At the time, the urban development area around Telenor's new headquarter (at the Fornebu area near Oslo) was subject to intense debates as to various more or less innovative public transport systems. The idea of a PRT came up as a possible local solution as well as a business opportunity. In 2000, The Fornebu/Oslo PRT Project started as a part of an internal educational exercise within ICT strategy innovation within Telenor ASA, a major ICT corporation. As the poster shows, the student project was later transformed into a fast working concept, technology and business development project with various industry partners and a project group of around 10. The Korean steel company POSCO joined in, and developed the project further in Uppsala, Sweden, in part through new partners, but with all essential elements from the Fornebu/Oslo PRT Project, as further industrial or governmental support found in the Oslo area vanished. The poster describes the consortium and main results from the Oslo PRT project period. Key persons in this concept development phase were - as to technology and operational features development - Ingmar Andreasson, Göteborg, Sweden, Jan Orsten, indep. traffic planner, Oslo, Alan Forster, Force Ltd, GB, and Andrew Howard, HWG Ltd, GB. Beyond the general conceptual description, the ICT systems were developed by Noventus AB and others at later stages.

In 2007, the Polish PRT system MISTER was prototyped, and permission was given to install it in two Polish cities. MISTER is a typical overhead PRT system engineered for economical aerial reuse of streets' right of ways, that still gives ground-level access to wheelchairs and freight.

System design[link]

Among the handful of prototype systems (and the larger number that exist on paper) there is a substantial diversity of design approaches, some of which are controversial.

Vehicle design[link]

Vehicle weight influences the size and cost of a system's guideways, which are in turn a major part of the capital cost of the system. Larger vehicles are more expensive to produce, require larger and more expensive guideways, and use more energy to start and stop. If vehicles are too large, point-to-point routing also becomes less economically feasible. Against this, smaller vehicles have more surface area per passenger (thus have higher total air resistance which dominates the energy cost of keeping vehicles moving at speed) and larger motors are generally more efficient than smaller ones.

The number of riders who will share a vehicle is a key unknown. In the U.S., the average private automobile carries 1.16 persons,^[49] and most industrialized countries commonly average below two people; not having to share a vehicle with strangers is a key advantage of private transport. Based on these figures, some have suggested that two passengers per vehicle (such as with UniModal), or even a single passenger per vehicle is optimum. Other designs use an auto for a model, and choose larger vehicles, making it possible to accommodate families with small children, riders with bicycles, disabled passengers with wheelchairs, or a pallet or two of freight.

Propulsion[link]

All current designs (except for the human-powered Shweeb) are powered by electricity. In order to reduce vehicle weight, power is generally transmitted via lineside conductors rather than using on-board batteries. According to the designer of Skyweb/Taxi2000, J. Edward Anderson, the lightest system is a linear induction motor (LIM) on the car, with a stationary conductive rail for both propulsion and braking. LIMs are used in a small number of rapid transit applications, but most designs use rotary motors. Most such systems retain a small on-board battery to reach the next stop after a power-failure.

ULTra uses on-board batteries, recharged at stops. This increases the safety, and reduces the complexity, cost and maintenance of the guideway. As a result, a grade-level ULTRa guideway resembles a sidewalk with curbs and is very inexpensive to construct. ULTRa resembles a small automated electric car, and uses similar components.

Switching[link]

Most designers avoid track switching, instead advocating vehicle-mounted switches or conventional steering. Those designers say that vehicle-switching permits faster switching, so vehicles can be closer together. It also simplifies the guideway, makes junctions less visually obtrusive and reduces the impact of malfunctions, because a failed switch on one vehicle is less likely to affect other vehicles. Other designers point out that track-switching simplifies the vehicles, reducing the number of small moving parts in each car. Track-switching replaces in-vehicle mechanisms with larger track-moving components, that can be designed for durability with little regard for weight or size.

Track switching greatly increases headway distance. A vehicle must wait for the previous vehicle to clear the track, for the track to switch and for the switch to be verified. If the track switching is faulty, vehicles must be able to stop before reaching the switch, and all vehicles approaching the failed junction would be affected.

Mechanical vehicle switching minimizes inter-vehicle spacing or headway distance, but it also increases the minimum distances between consecutive junctions. A mechanically switching vehicle, maneuvering between two adjacent junctions with different switch settings cannot proceed from one junction to the next. The vehicle must adopt a new switch position, and then wait for the in-vehicle switch's locking mechanism to be verified. If the vehicle switching is faulty, that vehicle must be able to stop before reaching the next switch, and all vehicles approaching the failed vehicle would be affected.

Conventional steering allows a simpler 'track' consisting only of a road surface with some form of reference for the vehicle's steering sensors. Switching would be accomplished by the vehicle following the appropriate reference line- maintaining a set distance from the left roadway edge would cause the vehicle to diverge left at a junction, for example.

Infrastructure design[link]

Simplified depiction of a possible PRT network. The blue rectangles indicate stations. The enlarged portion illustrates a station off-ramp.

Guideways[link]

There is some debate over the best type of guideway. Among the proposals are beams similar to monorails, bridge-like trusses supporting internal tracks, and cables embedded in a roadway. Most designs put the vehicle on top of the track, which reduces visual intrusion and cost as well as easing ground-level installation. An overhead track is necessarily higher, but may also be narrower.^[6] Most designs use the guideway to distribute power and data communications, including to the vehicles. The Morgantown PRT failed its cost targets because of its steam-heated track^{[citation needed]}, so most proposals plan to resist snow and ice in ways that should be less expensive.

Stations[link]

Proposals usually have stations close together, and located on side tracks so that through traffic can bypass vehicles picking up or dropping off passengers. Each station might have multiple berths, with perhaps one-third of the vehicles in a system being stored at stations waiting for passengers. Stations are envisioned to be minimalistic, without facilities such as rest rooms. For elevated stations, an elevator may be required for accessibility.

At least one system, MISTER provides wheelchair and freight access by using a cogway in the track, so that the vehicle itself can go from a grade-level stop to an overhead track.

Some designs have included substantial extra expense for the track needed to decelerate to and accelerate from stations. In at least one system, Aramis, this nearly doubled the width and cost of the required right-of-way and caused the nonstop passenger delivery concept to be abandoned. Other designs have schemes to reduce this cost, for example merging vertically to reduce the footprint.

When user demand is low, surplus vehicles could be configured to stop at empty stations at strategically placed points around the network. This enables an empty vehicle to quickly be despatched to wherever it is required, with minimal waiting time for the passenger.

Operational characteristics[link]

Headway distance[link]

Spacing of vehicles on the guideway influences the maximum passenger capacity of a track, so designers prefer smaller headway distances. Computerized control theoretically permits closer spacing than the two-second headways recommended for cars at speed, since multiple vehicles can be braked simultaneously. There are also prototypes for automatic guidance of private cars based on similar principles.

Very short headways are controversial. The UK Railway Inspectorate has evaluated the ULTra design and is willing to accept one-second headways, pending successful completion of initial operational tests at more than 2 seconds.^[50] In other jurisdictions, existing rail regulations apply to PRT systems (see CVS, above); these typically calculate headways in terms of absolute stopping distances, which would restrict capacity and make PRT systems unfeasible. No regulatory agency has yet endorsed headways below one second, although proponents believe that regulators may be willing to reduce headways as operational experience increases.^[51]

Capacity[link]

PRT is usually proposed as an alternative to rail systems, so comparisons tend to be with rail. PRT vehicles seat fewer passengers than trains and buses, and must offset this by combining higher average speeds, diverse routes, and shorter headways. Proponents assert that equivalent or higher overall capacity could be achieved by these means. Since there are no full-scale installations, capacity calculations are based on simulation and modeling.

Single line capacity[link]

With two-second headways and four-person vehicles, a single PRT line can achieve theoretical maximum capacity of 7,200 passengers per hour. However, most estimates assume that vehicles will not generally be filled to capacity, due to the point-to-point nature of PRT. At a more typical average vehicle occupancy of 1.5 persons per vehicle, the maximum capacity is 2,700 passengers per hour. Some researchers have suggested that rush hour capacity can be improved if operating policies support ridesharing.^[52]

Capacity is inversely proportional to headway. Therefore, moving from two-second headways to one-second headways would double PRT capacity. Half-second headways would quadruple capacity. Theoretical minimum PRT headways would be based on the mechanical time to engage brakes, and these are much less than a half second. Although no regulatory agency has as yet (June 2006) approved headways shorter than two seconds, researchers suggest that high capacity PRT (HCPRT) designs could operate safely at half-second headways.^[53] Using the above figures, capacities above 10,000 passengers per hour seem in reach.

In simulations of rush hour or high-traffic events, about one-third of vehicles on the guideway need to travel empty to resupply stations with vehicles in order to minimize response time. This is analogous to trains and buses travelling nearly empty on the return trip to pick up more rush hour passengers.

Grade separated light rail systems can move 15,000 passengers per hour on a fixed route, but these are usually fully grade separated systems. Street level systems typically move up to 7,500 passengers per hour. Heavy rail subways can move 50,000 passengers per hour. As with PRT, these estimates depend on having enough trains. Neither light nor heavy rail scales well for off-peak operation.

Networked PRT capacity[link]

The above discussion compares line or corridor capacity and may therefore not be relevant for a networked PRT system, where several parallel lines (or parallel components of a grid) carry traffic. In addition, Muller estimated^[54] that while PRT may need more than one guideway to match the capacity of a conventional system, the capital cost of the multiple guideways may still be less than that of the single guideway conventional system. Thus comparisons of line capacity should also consider the cost per line.

PRT systems should require much less horizontal space than existing metro systems, with individual cars being typically around 50% as wide for side-by-side seating configurations, and less than 33% as wide for single-file configurations. This is an important factor in densely populated, high-traffic areas.

Travel speed[link]

For a given peak speed, nonstop journeys are about three times as fast as those with intermediate stops. This is not just because of the time for starting and stopping. Scheduled vehicles are also slowed by boardings and exits for multiple destinations.

Therefore, a given PRT seat transports about three times as many passenger miles per day as a seat performing scheduled stops. So PRT should also reduce the number of needed seats threefold for a given number of passenger miles.

While a few PRT designs have operating speeds of 100 km/h (60 mph), and one as high as 241 km/h (150 mph),^[55] most are in the region of 40–70 km/h (25–45 mph). Rail systems generally have higher maximum speeds, typically 90–130 km/h (55–80 mph) and sometimes well in excess of 160 km/h (100 mph), but average travel speed is reduced about threefold by scheduled stops and passenger transfers.

Ridership attraction[link]

If PRT designs deliver the claimed benefit of being substantially faster than cars in areas with heavy traffic, simulations suggest that PRT could attract many more automobile drivers than other public transit systems. Standard mass transit simulations accurately predict that 2% of auto drivers will switch to trains. These same methods predict that 25% to 60% of auto drivers would switch to PRT.^{[citation needed]}

Control algorithms[link]

The typical control algorithm places vehicles in imaginary moving "slots" that go around the loops of track. Real vehicles are allocated a slot by track-side controllers. Traffic jams are prevented by placing north/south vehicles in even slots, and east/west vehicles in odd slots. At intersections, the traffic in these systems can interpenetrate without slowing.

On-board computers maintain their position by using a negative feedback loop to stay near the center of the commanded slot. Early PRT vehicles measured their position by adding up the distance using odometers, with periodic check points to compensate for cumulative errors.^[39] Next-generation GPS and radio location could measure positions as well.

Another style of control assigns a path and speed to a vehicle, after verifying that the path does not violate the safety margins of other vehicles. This permits system speeds and safety margins to be adjusted to design or operating conditions, and may use slightly less energy.^[56] The maker of the ULTra PRT system reports that testing of its control system shows lateral (side-to-side) accuracy of 1 cm, and docking accuracy better than 2 cm.

Safety[link]

Computer control eliminates errors from human drivers, so PRT designs in a controlled environment should be much safer than private motoring on roads. Most designs enclose the running gear in the guideway to prevent derailments. Grade-separated guideways would prevent conflict with pedestrians or manually controlled vehicles. Other public transit safety engineering approaches, such as redundancy and self-diagnosis of critical systems, are also included in designs.

The Morgantown system, more correctly described as an Automated Guideway Transit system (AGT), has completed 110 million passenger-miles without serious injury. According to the U.S. Department of Transportation, AGT systems as a group have higher injury rates than any other form of rail-based transit (subway, metro, light rail, or commuter rail) though still much better than ordinary buses or automobiles. More recent research by the British company ULTra PRT reported that AGT systems have a better safety than more conventional, non-automated modes.^{[citation needed]}

As with many current transit systems, personal passenger safety concerns are likely to be addressed through CCTV monitoring^{[citation needed]}, and communication with a central command center from which engineering or other assistance may be dispatched.

Energy efficiency[link]

The energy efficiency advantages claimed by PRT proponents include two basic operational characteristics of PRT: an increased average load factor; and the elimination of intermediate starting and stopping.^[57]

Average load factor, in transit systems, is the ratio of the total number of riders to the total theoretical capacity. A transit vehicle running at full capacity has a 100% load factor, while an empty vehicle has 0% load factor. If a transit vehicle spends half the time running at 100% and half the time running at 0%, the average load factor is 50%. Higher average load factor corresponds to lower energy consumption per passenger, so designers attempt to maximize this metric.

Scheduled mass transit (i.e. buses or trains,) trades off service frequency and load factor. Buses and trains must run on a predefined schedule, even during off-peak times when demand is low and vehicles are nearly empty. So to increase load factor, transportation planners try to predict times of low demand, and run reduced schedules or smaller vehicles at these times. This increases passengers' wait times. In many cities, trains and buses do not run at all at night or on weekends.

PRT vehicles, in contrast, would only move in response to demand, which places a theoretical lower bound on their average load factor. This allows 24-hour service without many of the costs of scheduled mass transit.^[58]

ULTra PRT estimates its system will consume 839 BTU per passenger mile (0.55 MJ per passenger km).^[59][60] By comparison, automobiles consume 3,496 BTU, and personal trucks consume 4,329 BTU per passenger mile.^[61]

Due to PRT's efficiency, some proponents say solar becomes a viable power source.^[62] PRT elevated structures provide a ready platform for solar collectors, therefore some proposed designs include solar power as a characteristic of their networks.

For bus and rail transit, energy usage per passenger-mile is dependent on service frequency and ridership, and can vary significantly from peak to non-peak. Therefore, aggregate statistics are used to calculate overall energy usage passenger-mile. In the US, buses consume an average of 4,318 BTU/passenger-mile, transit rail 2,750 BTU/passenger-mile, and commuter rail 2,569 BTU/passenger-mile.^[61]

Cost characteristics[link]

The initial capital costs of PRT are large, but compare favorably with those of other transportation modes. Its system design tries to pay down those costs as quickly as possible, while maximizing the useful lifetime of the project. Proponents' cost estimates in passenger mile range from the cost of a bicycle (US $0.01–0.05/passenger-mile, Unimodal) to the cost of a small motorcycle ($0.20/passenger mile, TAXI 2000), and are strongly disputed by opponents. It's agreed that PRT systems require no individual license, parking or insurance fees, and buy energy in bulk from inexpensive providers.

Most of the initial investment is in guideways. Estimates of guideway cost range from US$0.8 million (for MicroRail) to $22 million per mile, with most estimates falling in the $10m to $15m range.^[63][64] These costs may not include the purchase of rights of way or system infrastructure, such as storage and maintenance yards and control centers, and reflect unidirectional travel along one guideway, the standard form of service in current PRT proposals. Bidirectional service is normally provided by moving vehicles around the block. To reach capacities of competing systems, a system requires thousands of vehicles. Some PRT proposals incorporate these costs in their per-mile estimates.

PRT designs generally assume dual-use rights of way, for example by mounting the transit system on narrow poles on an existing street. If dedicated rights of way were required for an application, costs could be considerably higher. If tunneled, small vehicle size can reduce tunnel volume compared with that required for an automated people mover (APM). Dual mode systems would use existing roads, as well as special-purpose PRT guideways. In some designs the guideway is just a cable buried in the street (a technology proven in industrial automation). Similar technology could equally be applied to private automobiles.

A design with many modular components, mass production, driverless operation and redundant systems should in theory result in low operating costs and high reliability. Predictions of low operating cost generally depend on low operations and maintenance costs. Whether these assumptions are valid will not be known until full scale operations are commenced since reliability cannot be proven by prototype systems.

Transportation systems allocate the cost of their roads by measuring wear. PRT routes are disaggregated, and vehicles only move to carry passengers, so PRT measures wear and energy based on passengers or weight carried, rather than vehicle schedules. This brings large theoretical savings compared to trains, but appears more expensive than buses and streetcars, whose roads are subsidized by sunk, preallocated fuel taxes.

So, some planners dispute the cost-estimates of PRT when compared to light rail systems, whose costs vary widely with non-grade-separated streetcars being relatively low cost and systems involving elevated track or tunnels costing up to US$200 million per mile.

Opposition and controversy[link]

Opponents to PRT schemes have expressed a number of concerns:

Technical feasibility debate[link]

The Ohio, Kentucky, Indiana (OKI) Central Loop Report^[65] compared the Taxi 2000 PRT concept proposed by the Skyloop Committee to other transportation modes (bus, light rail and vintage trolley). In the Taxi 2000 PRT system, the Loop Study Advisory Committee identified "significant environmental, technical and potential fire and life safety concerns…" and the PRT system was "…still an unproven technology with significant questions about cost and feasibility of implementation." Skyloop contested this conclusion, arguing that Parsons Brinckerhoff changed several aspects of the system design without consulting with Taxi 2000, then rejected this modified design.^[51] Despite the report's concerns regarding the implementation obstacles of PRT, the report did conclude that compared to the other alternatives, PRT offered the most acceptable point-to-point travel times,^[66] the most reliable service levels, the highest level of frequency of service and geography coverage, and was most able to maintain schedule.^[67] The report further concluded that, compared to the other alternatives, PRT would have over 3 times the ridership of the next closest alternative, including new transit riders over 9 times higher than the next closest alternative.^[68]

Vukan R. Vuchic, Professor of Transportation Engineering at the University of Pennsylvania and a proponent of traditional forms of transit, has stated his belief that the combination of small vehicles and expensive guideway makes it highly impractical in both cities (not enough capacity) and suburbs (guideway too expensive). According to Vuchic: "...the PRT concept combines two mutually incompatible elements of these two systems: very small vehicles with complicated guideways and stations. Thus, in central cities, where heavy travel volumes could justify investment in guideways, vehicles would be far too small to meet the demand. In suburbs, where small vehicles would be ideal, the extensive infrastructure would be economically unfeasible and environmentally unacceptable."^[69]

PRT supporters claim that Vuchic's conclusions are based on flawed assumptions. PRT proponent J.E. Anderson wrote, in a rebuttal to Vuchic: "I have studied and debated with colleagues and antagonists every objection to PRT, including those presented in papers by Professor Vuchic, and find none of substance. Among those willing to be briefed in detail and to have all of their questions and concerns answered, I find great enthusiasm to see the system built."^[69]

The manufacturers of ULTra acknowledge that current forms of their system would provide insufficient capacity in high density areas such as central London, and that the investment costs for the tracks and stations are comparable to building new roads, making the current version of ULTra more suitable for suburbs and other moderate capacity applications, or as a supplementary system in larger cities.

Lessons from baggage handling[link]

There is a history of PRT style systems constructed at airports for use in moving bags from check in to x-ray and loading points for various aircraft. Some of these systems failed or had problems and this has led to conclusions that PRT systems would fail in a similar way.^[70]

More recently however there have also been some significant success stories in this area. The Bagtrax system provided by Vanderlande Industries is successfully installed at 6 airports now. These include major airports such as Schiphol Airport in Amsterdam and Terminal 5 at Heathrow Airport, London. The performance of these modern systems exceed conventional conveyor systems by far. Also the "Telebag System" is operational in 5 airports including London's Luton Airport, which handles significant volumes of traffic. The "Autover System"^[71] is another that is also used at a number of airports. At Dubai Airport for example, 31 vehicles carry 1200 pieces of luggage per hour (one piece of luggage per vehicle) from 6 origins to 24 destinations along 618 m of track making 9 loops with 16 junctions.

Regulatory concerns[link]

Possible regulatory concerns include emergency safety, headways, and accessibility for the disabled. Many jurisdictions regulate PRT systems as if they were trains. At least one successful prototype, CVS, failed deployment because it could not obtain permits from regulators.^[72]

Also, several PRT systems have been proposed for California,^[73][74] but the California Public Utilities Commission (CPUC) states that its rail regulations apply to PRT, and these require railway-sized headways.^[75][76] The degree to which CPUC would hold PRT to "light rail" and "rail fixed guideway" safety standards is not clear because it can grant particular exemptions and revise regulations.^[77]

Other forms of automated transit have been approved for use in California, notably the Airtrain system at SFO. CPUC decided to not require compliance with General Order 143-B (for light rail) since Airtrain has no on-board operators. They did require compliance with General Order 164-D which mandates a safety and security plan, as well as periodic on-site visits by an oversight committee. ^[78]

If safety or access considerations require the addition of walkways, ladders, platforms or other emergency/disabled access to or egress from PRT guideways, the size of the guideway may be increased. This may impact the feasibility of a PRT system, though the degree of impact would be highly dependent on both the particular design and the municipality involved.

Concerns about PRT research[link]

Wayne D. Cottrell of the University of Utah conducted a critical review of PRT academic literature since the 1960s. He concluded that there are several issues that would benefit from more research, including: urban integration, risks of PRT investment, bad publicity, technical problems, and competing interests from other transport modes. He suggests that these issues, "while not unsolvable, are formidable," and that the literature might be improved by better introspection and criticism of PRT. He also suggests that more government funding is essential for such research to proceed, especially in the US.^[79]

New urbanist opinion[link]

Several proponents of new urbanism, an urban design movement that advocates for walkable cities, have expressed opinions on PRT.

Peter Calthorpe and Sir Peter Hall have supported^[80][81] the concept, but James Howard Kunstler disagrees: "If we're going to replace the car why do it with something that's not only like the car, but not really as good as the car? It just seems crazy." He also referred to PRT proponents as "a particular kind of crank".^[82]

Group rapid transit[link]

Group rapid transit (GRT) is similar to personal rapid transit but with higher-occupancy vehicles and grouping of passengers with potentially different origin-destination pairs. In this respect GRT can be seen as a sort of horizontal elevator.^[83] Such systems may have fewer direct-to-destination trips than single-destination PRT but still have fewer average stops than conventional transit, acting more as an automated share taxi system than a private cab system. Such a system may have advantages over low-capacity PRT in some applications, such as where higher passenger density is required or advantageous.^[83] It is also conceivable for a GRT system to have a range of vehicle sizes to accommodate different passenger load requirements, for example at different times of day or on routes with less or more average traffic.^[83][84] Such a system may constitute an "optimal" surface transportation routing solution in terms of balancing trip time and convenience with resource efficiency.^[83]

GRT has principally been proposed as a corridor service, where it can potentially provide a travel time improvement over conventional rail or bus and can also interface with PRT systems.^[83][84] However, GRT's necessary grouping of passengers makes it much less attractive in applications with lower passenger density or where few origin-destination pairs are shared among passengers.^[84]

The same passenger grouping and destination scheduling approach is used in some advanced elevators, in the form of a destination control system.

See also[link]

• Duke University Medical Center Patient Rapid Transit, a permanently discontinued personal rapid transit system.
• Slope car

References[link]

Specific references:

External links[link]

• "Will You Commute via PRT?" (CNN) -retrieved 31 March 2011
• Systems Analysis of Urban Transportation Systems, Scientific American, 1969, 221:19–27
• advancedtransit.org—A history of PRT.
• " Personal Rapid Transit" - Book containing papers from the proceedings of the 1973 International Conference on Personal Rapid Transit (published by the University of Minnesota)