The Pros and Cons of Personal Rapid Transit

by Troy Pieper

Imagine stepping into a little automated pod and being whisked to your downtown destination on an elevated rail. The concept, called Personal Rapid Transit (PRT), is meant to combine the benefits of cars and mass transit, and it is what some fiscal conservatives in the state legislature who don’t support other forms of mass transit are proposing for Minneapolis. Fridley-based Taxi 2000 Corporation is developing a PRT system, and wants to build a 2,200-square-foot Safety Certification and Training facility to test the technology, using private and public funds. Last week, House Republicans released a $683 million capital improvements package, which included $4 million in state bonds that will go to developing PRT. It is one of six bonding bills on PRT currently in the state legislature. But whether public money should go to the development of a technology that has never been proven and has, in some instances, been abandoned as a workable technology, when those dollars may better be spent on existing forms of transit, is a question some local politicians and activists wish to see addressed.

Taxi 2000 Corporation has built a prototypical 60-foot track with one three-person pod in its Fridley headquarters. The user would ride the elevated monorail by swiping a prepaid fare card, entering a destination in the computer at the station, stepping into the red pod and pressing the “go” button. It is the culmination of more than 35 years of work on PRT by Taxi 2000 CEO Dr. J. Edward Anderson, perhaps the foremost promoter of the concept in North America. He first began working on PRT in 1968 as a mechanical engineering professor at Boston Univesity. After learning about the concept and finding it to be “a hell of an interesting idea,” he assembled a team of professors from various fields and submitted a proposal to study PRT to the Urban Mass Transit Association, created by the federal government in 1966 to address the nation’s burgeoning traffic congestion problems. The association gave Anderson enough money to travel the United States examining existing transit systems. He even gave a presentation to Nixon’s science advisory council. In 1970, the Minnesota legislature gave him $50,000, which he used to run a national conference on PRT. Now private investors are responsible for the Taxi 2000 Corporation.

But Anderson wasn’t the only one advocating for PRT. Other promoters and the media touted it in the ’60s and ’70s as “an important factor in clearing up our streets and highways and cleaning up our air,” as Metropolitan magazine reported in 1972. In 1979, Samy E. G. Elias, an engineering professor at West Virginia University at Morgantown designed a system of automated, van-sized vehicles on an elevated rail that connects the university’s campuses for students and faculty. The system was built, but at a cost of $126 million, $112 million more than Elias’ estimate.

One of the advantages of PRT is its relatively low cost, promoters say. Yet, another project headed by the Northeastern Illinois Regional Transportation Authority (RTA) in the mid-1990s failed to be implemented due to high costs. “Personal Rapid Transit—Cyberspace Dream Keeps Colliding with Reality,” an article found on www.lightrailnow.org, reports that Anderson licensed his technology to Raytheon, a major military contractor, in 1993. RTA studied PRT and found a system in Rosemont Ill., a Chicago suburb, to be feasible. According to lightrailnow.org, after RTA was “lured by Raytheon’s promise of a “1.3 percent commission on any additional sales of the PRT 2000 technology, [they] bought heavily into the venture investing tens of millions of dollars in a proposed PRT system” that would connect the O’Hare airport and RTA’s Blue Line rail transit station. A November 1998 UTU Daily News Digest article reported that RTA director Valerie Jarrett said there were “unanswered questions,” such as costs exceeding Raytheon’s estimates, which the article reported had already reached a level 50 percent higher than the original estimates. RTA and Raytheon stopped work on the project in 1999, and a Spring 2000 Advanced Transit Association Newsletter reported that Lightrailnow.org related that “total public and private investment in the project came to $67 million … almost all of which was wasted” said lightrailnow.org.

Another Corporation, Advanced Transport Systems Limited (ATS), interested the Cardiff, Wales County Council in their PRT technology last year, but, according to a 2003 article on bbc.com entitled “Green Transport System Dealt Blow,” the Welsh administration voted not to give the proposed 8.8 million pounds to develop it. ATS built a test track like the one proposed by Taxi 2000, which can be seen at http://www.atsltd.co.uk/. Except for one section between two large abutments of dirt with a single support post between them, the test track is not elevated, which calls into question the strength of that post and the entire system’s design.

Wales’ Environment Minister helped publicize the PRT project, because of its “green” electric power system, while Welsh environmental organization Friends of the Earth Cymru supported the decision not to fund the project, saying in the article that the Cardiff Council “had not thought the system through thoroughly.” The leader of the Lib Dems group on the council said, “We think we should really be looking at something which is a mass transportation system. Who wants to be taking that sort of risk with public money?” Interestingly, the article also reported that the council’s annual funding was cut when census information showed Cardiff’s population “was less than at first believed,” and that the council had also asked the Welsh administration for a road into Cardiff Bay, the same destination as the proposed PRT system.

Similar to the Cardiff PRT plan, a local environmentalist City Councilmember Dean Zimmermann is pushing PRT in Minneapolis, because of the need for a green transit system. He says that all of the projects discussed in city council meetings end up in arguments about parking. He also says that PRT would compete with cars and use only one quarter of the energy per passenger mile that light real transit uses, which would help keep Minneapolis from exceeding acceptable federal air quality standards such as ground level ozone level and amount of particulate matter. Zimmermann is proposing a 31-mile, 68-station PRT network, which can be seen on the Citizens for PRT website at cprt.com. The network would connect downtown Minneapolis with several other areas of the city, as well as to the new Light Rail line at four points, including two shared Light Rail / PRT stations. The councilmember hopes to see more state support of Taxi 2000’s PRT design, because, he says, there is the potential for a new industry to begin in Minneapolis and because he believes it is the role of the state to attract private investors in that potential. Zimmermann has teamed up with Republican State Representative Mark Olson, who has historically opposed other forms of mass transit like light rail and commuter rail, to promote PRT.

Zimmermann’s party, the Green Party, is however, apparently distancing itself from Zimmermann. Annie Young of the party said, “This is not a Green Party issue; this is Dean’s project. I’m concerned about his relationship to Taxi 2000, and about the time he’s spending on the project and whether he’s meeting the needs of the people in his ward. There are potentially some good things that could come from it, and I see what the point is but I’m not sure the timing is right. There are also a lot of questions about it, like why are the Republicans so interested in it? There are a lot of good alternatives that we should be working on, and there are so many transportation needs to be addressed. I’m just not sure this is the best one.”

The April issue of the Rake reported that the Green Party’s Betsy Barnum “would like to see adequate funding for the bus system before $60 million is spent testing PRT.” Tim King writes in the article that “she wonders if people will tolerate the overhead guideways, and what happens when the system shuts down and suspends a few thousand people above Marquette?” The North Star Chapter of the Sierra Club agreed in a recent resolution to support “buses as primary feeders,” “a network LRT and commuter rail serving the Twin Cities region,” and to recognize that “businesses and academic campuses,” such as Morgantown, “may be appropriate for other technologies.” The resolution also states that fixed transit guideway is costly and difficult to site and that it “must maximize cost benefit while minimizing visual obstruction and urban forest canopy impact.” This is particularly significant, since Zimmermann has gotten many trees planted along the Midtown Greenway in his district. A part of his proposed PRT system will run through that area, in which case Zimmermann says parabolic arches will support the guideway.

One of the questions about PRT is, as Betsy Barnum said in the April Christian Science Monitor, whether people will tolerate the visual intrusion of the overhead guideways. Parabolic arches will certainly require more tolerance.

Dr. Vukan R. Vuchic, professor of Engineering at the University of Pennsylvania, has written extensively on PRT. In his book, “Transportation for Livable Cities,” he writes, “Non-conventional transit modes often attract attention because of their innovative image and exotic features. It takes considerable understanding of transportation systems to distinguish their advantageous features from the features that make them inferior to conventional modes or even, in one case (personal rapid transit, or PRT), functionally infeasible.There are entire modes that are conceptually unsound but that attract the attention of the public. Promotional efforts by some inventors, as well as the naive views of inexperienced theoreticians, often cause confusion and costly delays when cities intend to develop new transit systems.

An urban designer, Jason Haremza, wrote a comment on planetizen.com comparing PRT to a particularly insightful episode of the Simpsons in which a huckster-ish character comes to Springfield and sells the citizens a “high-tec, gee-whiz sort of transit system, which immediately falls apart, while Main Street remains cracked and broken.” He offers the solution of dedicating two lanes of roadway for LRT only, while keeping at least one lane in each direction for auto traffic. “This has been done with great success in Toronto and other cities. Many, if not most streets are wide enough for 48 feet of pavement that this simple, affordable, and efficient solution requires.” Vuchic also writes, in “Personal Rapid Transit: An Unrealistic System,” that PRT tries to combine the two mutually incompatible elements of personal service by private car and the high efficiency of rapid transit, rendering it an unfeasible concept. However, Mark Reilly wrote in a recent article in The Business Journal that, according to Catherine Burke, a professor at the University of Southern California’s School of Public Administration and the president of the Advanced Transit Association, a group that studies technologies such as PRT, “Taxi 2000 has unfairly suffered criticism because it’s so different from conventional transit systems. ‘The mass-transit people are so convinced it’s unworkable they won’t even look at the analysis, and the politicians are scared that something will go wrong,’” Burke said.

In what is perhaps the best example of the debate surrounding PRT technology, the Ohio-Kentucky-Indiana (OKI) Regional Council of Governments hired independent consultants Parsons-Brinkerhoff to evaluate Taxi 2000’s PRT proposal for a system linking the downtowns of Cincinnati, Ohio, and Covington and Newport, Northern Kentucky in what was called the Central Area Loop Study (CALS). In the year 2000, CALS’s Draft Final Report (DFR), which cost $625,000, did not recommend personal rapid transit or Taxi 2000 for adoption as the technology for the area circulator, because of “significant environmental, technical, and potential fire and life safety concerns accompanying the implementation of such a system. Many of these concerns stem from the elevated design of the system.” It raised questions “regarding engineering design, operational feasibility and cost.” Later that year, Anderson of Taxi 2000 wrote a Rebuttal to the DFR, citing Parsons Brinckerhoff”s “numerous errors and incorrect assumptions” about PRT, which were a result of their “limited experience with PRT, limited information received by them on Taxi 2000 system design and engineering which they did not ask for [and] the major mistake of acting beyond the scope of the study by attempting to re-engineer the Taxi 2000 design.” The study claimed that a sufficient amount of data to compare PRT to “more available historic data” on other forms of transit was simply not provided by Taxi 2000, implying that it was asked for.

The report stated that because Taxi 2000’s design had existed for 20 years without a viable system being implemented, it would have to conform to current regulations and standards such as those for wheelchair access. Anderson’s rebuttal reported that the 60-inch minimum diameter envelope needed for wheelchair access in the Accessibility Handbook for Transit Facilities referred to by Parsons-Brinckerhoff was only necessary in transit stations and stops, but not in vehicles themselves. The Americans with Disabilities Act specifies a minimum clear space of 48 inches by 30 inches in vehicles, with which Taxi 2000’s design is consistent. The Act does not require, Anderson reports, “wheelchairs to face forward, except in buses and vans, or to be able to execute a 360-degree turn.” Technical problems concerning the construction of the guideway, which required changes in the design that made the system more expensive were, according to Anderson’s rebuttal, because Parsons-Brinckerhoff did not use the 1991 report on Taxi 2000’s design done by Stone and Webster for the Chicago RTA. However, it seems reasonable for the OKI to want an independent evaluation on PRT done by a consultant of their choice.

Safety issues are raised in the OKI report such as fire safety, visibility hazards presented by the support columns for roadway vehicles and pedestrians (not to mention what would happen if a driver loses control of her or his vehicle near the columns) and emergency evacuation from a stationary car, since there are no walkways along the guideway in the design. Problems affecting the efficiency of the PRT system such as the length of time passengers would have to wait for a car, headway (the nose-to-nose distance vehicles traveling on the guideway) and noise created by the system, were also raised in the OKI report. The changes to the design assumed by the report made the system much more expensive (which made projected fares in the report potentially prohibitive for low-income riders), but Anderson’s rebuttal assures they are not necessary and are simply a result of a failure to follow Taxi 2000’s design. Throughout the report he writes, “Parsons Brinckerhoff assumes a worst-case scenario for PRT … It is very easy to take this position for a system that has not yet been built.” It would be just as easy, one might think, to take the opposite position, but perhaps it is not the best one when considering the safety of an unproven technology.

More superficial concerns in the report refer to the physical and visual barriers presented to buildings with windows facing the guideway at the same elevation and to “viewers of historic structures.” The guideways won’t be consistent with the character of historic neighborhoods, states the report. However, Mike Lester, the president and chief operating officer of taxi 2000 and a former employee in Texas’ oil industry, says that the guideways can be painted to look like their backgrounds. The ultramodern appearance of the vehicles, however, would not blend into a background. Anderson states in his rebuttal that, “as we have utilized new technologies for enhanced mobility, power and communications, we place less importance on the visual intrusiveness of these systems while the evolving built-environment is adapted to their presence.”

Lester also addressed other criticisms of PRT. Snow and ice falling from the guideway, for example, would be falling through the open middle of the guideway where pedestrians won’t be walking anyway. And because of the relatively few moving parts in Taxi 2000’s pod, “there wouldn’t be any system droppings like grease,” he says. The expensive designs of past projects like Raytheon’s had many more moving parts, instead of the frictionless Linear Induction Motors of Taxi 2000’s current design, which he says would require much less maintenance. And many of its parts, like the Rollerblade wheels he points out, are already mass produced, keeping the system’s cost down.

The OKI report brings up issues of personal security, as well, stating that the elevated stations “may feel isolated from normal street activity due to their location, which may make some passengers feel unsafe,” because they are more difficult for police to patrol than street level transit stops. “The possibility of an unwanted passenger entering a PRT vehicle can be problematic,” the report states. On Taxi 2000’s skwebexpress.com website, one of the “Questions and Answers About Personal Rapid Transit” is “Will you have to ride with strangers?” The answer is “No!” “If someone tries to force his way into a vehicle, a button can be pushed inside the vehicle to alert police.” Taxi 2000 also says that the shorter wait times at PRT stations leave less time for passengers to be vulnerable to acts of aggression, and the stations will be equipped with television monitors and voice communication devices. However, if a station looks dangerous to a rider as he or she approaches it in a vehicle, there is, according to the OKI report, no way to continue on to the next station, because PRT is completely automated, which “may make some users feel uneasy.”

The debate about PRT and mass transit, however, is not limited to their specific technical aspects. As the kind-faced Ed Anderson has said, “Let’s face it, it’s political. People worry that they’ve been working for years to get a train and all these guys come in with new ideas. There gets to be constituencies behind it. People think it’s either/or, buses and trains or PRT, but it would be integrated.” Local activists like Ken Avidor think otherwise. He believes that PRT is a much more complicated, multi-layered debate complete with an anti-transit layer. “The whole thing is developed to waste time. It’s a way of diverting attention away from the real question, which is roads or transit. They can argue endlessly, because PRT doesn’t exist. It’s like boxing with a ghost. Like the trees in the midtown greenway. [Anderson] just says they’ll suspend the guideway from parabolic arches. Or skyways: he says the guideway will go over them. What will the support structures for a three-story high guideway look like?”

Former Chairman of the Board of Directors of Taxi 2000, A. Sheffer “Shef” Lang, who died last year, writes on skywebexpress.com about removing rails from cities and about how the highway “sets the industry standard” for transportation. Avidor has compiled quotes from Lang on his website, http://www.roadkillbill.com/PRTisaJoke.html, in which the former chairman calls Amtrak 19th-Century technology and advocates for the privatization of mass transit. “If [the high-speed rail market] were run by a private corporation instead of by this Mickey Mouse government-supported operation, mainly Amtrak, they might be able to hang in there as a private entity and do reasonably well,” he says in a quote on http://woodrow.mpls.frb.fed.us/pubs/fedgaz/02-03/rail.cfm. On http://faculty.washington.edu/%7Ejbs/itrans/lang.htm, Lang says that there is no longer reason to let transportation decisions be made by governments, that the market could sort them out. Anderson recalls, on Taxi 2000’s website, that Lang, who was Professor of Transportation at MIT, said at a meeting in his office that “he and his colleagues had calculated that if Boston ripped up all of their rail systems and replaced them with PRT with the same line and station locations it could handle the traffic carried by the rail system at substantially lower annual cost.”

PRT critics on www.cprt.org have accused the concept of being an excuse for right-wing Republican policymakers such as Olson and the pro-highway Senator Michelle Bachman to vote for automobile infrastructure, while supporting PRT as an alternative to mass transit. The claims of conspiracy theorists resemble the actual events that brought an end to the nation’s streetcar system in the 1930s. Also documented in a PBS documentary “Taken for a Ride,” Edward R. Miller in a September 1997 issue of The Coastal Post writes that Alfred P. Sloan Jr., the president of General Motors, with the help of corporations like Firestone, Standard Oil and Mack Truck, formed the bus company National City Lines, using a figurehead of the unknown E. Roy Fitzgerald. They used “political know-how and money to influence city councils, while they paid Madison Avenue to tell the country “the trend was away from rail” [and] systematically destroyed America’s clean, electric rail systems, replacing them with their polluting diesel buses. By 1941, National City Lines owned the transportation system in over 83 American cities across the country.”

Dean Zimmermann says it is “absurd” to think that PRT has anything to do with a conspiracy against mass transit. “Every supporter of PRT,” he says, “has unique reasons to do so.” Representative Olson, who supports buses but not light rail, agrees. “It’s just a brilliant idea that is going to enhance and support existing forms of transit. How could 36 years of Anderson’s work and $30 million, plus agreements for dividends with the University of Minnesota, be defined as an effort to move us away from other forms of transit? … A conspiracy would mean that we would support PRT until other forms of transit die and then drop PRT,” which he says is ridiculous. He believes that Minnesota taking the lead in the industry of PRT would benefit the whole state, and that PRT will draw people out of their cars by their own choosing, while advocates of proven forms of transit have to work to draw support for those forms.

One of the companies working with Taxi 2000 is Short Elliot Hendrickson (SEH), a highway construction engineering firm in St. Paul, which has recently come under fire for over-billing the Minnesota Department of Transportation (MnDoT). According to a January Star Tribune article, MnDoT signed a three-year, $750,000 contract with SEH to design roads. “Two years into the contract,” the article states, the firm “tagged on an amendment for $750,000, citing the heavy workload. It was among eight SEH contracts with supplements exceeding 60 percent of their original value.”

Amendments, reports the article, are allowed by state law, but “regulators have noted that the practice can be used to skirt competitive bidding requirements.” In addition to supporting and contributing to Taxi 2000, SEH are the consultants on the 35W Access Project, a highway expansion project. An April 19th article in the Princeton Union-Eagle also reported that the general contractor with the winning bid for the engineering of an upcoming road construction project in that city bid nearly $1 million less than SEH did for the same project.

Contrary to the innovative concept and advanced technology that Taxi 2000 claims will make it a success, Michael D. Setty, a transportation consultant, and Leroy W. Demery Jr., a transport research specialist, analyst and author, published an article on planetizen.com called “Conventional Rail vs. ‘Gadgetbahnen.’” In it they contend that “U.S. transportation problems are almost always sociopolitical and economic—not technical—in nature.” For example, a severe limitation of [technologies such as PRT] is the very high cost of introducing entirely new infrastructure into urban areas, versus the relatively low cost of upgrading existing rail lines.”

They concede, as do other critics of PRT, that this specialized technology may be successful in niche markets such as airports, amusement parks or universities. The University of Minnesota helped launch Taxi 2000 in 1988 with a $100,000 patent development grant, according to a June 2002 article in Finance and Commerce. The two have an agreement that expires in 2013, under which the University’s five PRT-related patents would bring it $10,000 for each mile of guideway built and $135 for each vehicle in use. There are no plans to implement a PRT system on the University campus. Representative Frank Hornstein, DFL-Minneapolis, told MPR’s Laura McCallum on April 23 that he was “surprised to see PRT money in the bill … Where it has really seriously been studied—and that is in Cincinnati, Ohio, and Rosemont, Illinois—thorough studies done by credible public agencies, they’ve simply said that this is not viable.” Hornstein says no Minnesota city has asked the Legislature for funding for PRT, and he says it’s an unproven technology.

“I think part of the problem with this is that it has not received a lot of public scrutiny.”