Editing Personal rapid transit (section)

==Opposition and controversy==
Opponents to PRT schemes have expressed a number of concerns:

===Technical feasibility debate===
[[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."<ref name="vuchic">{{cite web
 | last=Vuchic | first=Vukan R
 | url=http://faculty.washington.edu/jbs/itrans/vuchic1.htm
 | title= Personal Rapid Transit: An Unrealistic System
 | date=September–October 1996
 | work = Urban Transport International (Paris), (No. 7, September/October, 1996)
 | access-date = 30 August 2017
}}</ref>

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."<ref name="vuchic"/>

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.{{citation needed|date=August 2017}}

===Regulatory concerns===
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.<ref>See the references in [[Computer-controlled Vehicle System]]</ref>

Several PRT systems have been proposed for [[California]],<ref>See [http://www.santacruzprt.com/ www.santacruzprt.com] {{Webarchive|url=https://web.archive.org/web/20110208110916/http://santacruzprt.com/ |date=2011-02-08 }}.</ref><ref>[[Skytran]] was proposed for [[Orange County, California]], by its inventor, Maliwicki, who lives in that area</ref> but the [[California Public Utilities Commission]] (CPUC) states that its rail regulations apply to PRT, and these require railway-sized headways.<ref name="cpuc.ca.gov">{{cite web|url=http://www.cpuc.ca.gov/PUC/documents/go.htm|title=We're so sorry, your page was Not Found!|url-status=dead|archive-url=https://web.archive.org/web/20091231144823/http://www.cpuc.ca.gov/PUC/documents/go.htm|archive-date=2009-12-31}}</ref> 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.<ref>California General Order 164-D, ibid. Sections 1.3,1.4</ref>

Other forms of automated transit have been approved for use in California, notably the Airtrain system at [[San Francisco International Airport|SFO]]. CPUC decided not to 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.<ref>{{cite web|url=http://docs.cpuc.ca.gov/published/Agenda_decision/22480-07.htm|title=Walker Agenda Dec - Order Concluding that Commission has Safety Jurisdiction Over SFO AirTrain}}</ref>

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 depend on both the PRT design and the municipality.

===Concerns about PRT research===
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 United States.<ref>{{cite conference
| last=Cottrell | first=Wayne D
| conference=Automated People Movers 2005: Moving to Mainstream
|title=Critical Review of the Personal Rapid Transit Literature
| publisher=ASCE
| date=May 1–4, 2005| journal = Proceedings of the 10th International Conference on Automated People Movers
| pages=1–14
| doi=10.1061/40766(174)40
| isbn=978-0-7844-0766-0
}}</ref>

===New urbanist opinion===
Several proponents of [[New Urbanism|new urbanism]], an urban design movement that advocates for [[walkability|walkable cities]], have expressed opinions on PRT.

[[Peter Calthorpe]] and [[Peter Hall (urbanist)|Sir Peter Hall]] have supported<ref>[http://www.planetizen.com/node/17760 Personal Rapid Transit for Heathrow Airport, Dubai Financial Center] from planetizen.com</ref><ref>[http://www.planning.org/lenfant/pdf/hall2005transcript.pdf Sir Peter Hall: "The Sustainable City: A Mythical Beast?" Transcript]{{dead link|date=March 2018 |bot=InternetArchiveBot |fix-attempted=yes }} from planning.org</ref> the concept, but [[James Howard Kunstler]] disagrees.<ref>{{usurped|1=[https://web.archive.org/web/20190809194514/http://kunstlercast.com/ KunstlerCast #13: Personal Transit & Green Buildings]}} from kunstlercast.com</ref>

===PRT vs. autonomous vehicles===
As the development of self-steering technology for [[autonomous car]]s and shuttles advances,<ref>{{cite web|title=5 Companies Working On Driverless Shuttles And Buses|url=https://www.cbinsights.com/research/driverless-shuttle-companies/|publisher=CB Insights|access-date=30 August 2017|date=March 30, 2017}}</ref> the guideway technology of PRT seems obsolete at first glance.  Automated operation might become feasible on existing roads too. On the other hand, PRT systems can also make use of self-steering technology and significant benefits remain from operating on a segregated route network.