Why, After Decades, Has Personal Rapid Transit Not Yet Been Widely
by J. Edward Anderson, Ph.D., P. E.
April 19, 1997
I am frequently asked: If PRT is such a good idea and one that has been around for
decades, why hasn't it been widely accepted? There was considerable interest in PRT in the
late 1960s and early 1970s, so much that the idea caused several proposed heavy rail
projects to be stopped. Capital grants had become available for conventional rail systems
and the promoters of such systems, who had the dominant lobbying power in transit circles,
found that PRT adversely affected their plans. They therefore persuaded Congress to
eliminate the competition of a compelling new idea. But, the need for PRT could not be
eliminated, and it is now in a state of reemergence.
Early Interest in PRT
In 1964 Congress created UMTA (the Urban Mass Transportation Administration), not only
to revive dying municipal bus companies, but to fund the deployment of BART-type rapid
rail systems in cities all over the United States. Evidently the lobbyists for the status
quo did not perceive that the new organization would get involved with new systems,
and they failed to stop placement of a paragraph in the UMTA Act that directed that new
systems be studied. Of 17 studies authorized, one can still be found in libraries in
summary form . Its key conclusions are the following:
"In general, the results of our analysis made clear that, even with the most
optimistic view of what might be achieved through improvement of the existing methods of
transportation, such improvement cannot satisfy the real needs of our cities in terms of
"Computer models of cities suggest that in certain circumstances installing novel
`personal transit' systems may already be more economic than building conventional systems
such as subways."
On January 21, 1972 the New York Times  announced that the Nixon
Administration was embarking on a program "for using technology to improve our
everyday lives." The first project named was the development of a high-capacity PRT
This announcement followed:
a) Completion in 1968 of the above-mentioned studies on new personal transit systems
funded by UMTA at $500,000 each, which showed strongly positive benefits from the
deployment of PRT systems;
b) Start of federally-funded work on the Morgantown so-called
c) Reports of extensive work on PRT in many places around the world, as reported in
November 1971 at the National Conference on Personal Rapid Transit; and
d) Detailed study of PRT by a group of NASA engineers working in the Executive Office
of the President, including study of the excellent work which the Aerospace
Corporation had been doing on a small-guideway, high-capacity PRT system, which had
minimal visual impact and modest costs.
(The Aerospace Corporation had perhaps the finest group of system engineers in the
world. Their PRT work was outstanding and was so recognized by the White House, whose
initiative was directed at further development of the Aerospace PRT
In March 1973 UMTA Administrator Frank Herringer testified to the House Appropriations
Committee  that "...a high-capacity PRT could carry as many passengers as a rapid
rail system for about one quarter the capital cost."
The record of those hearings contains a quantitative comparison of PRT and
conventional rail systems that supports this statement. Herringer went on to say: "A
DOT program leading to the development of a short, one-half to one-second headway,
high-capacity PRT system will be initiated in fiscal year 1974."
The Aerospace Corporation would have led this development program.
In September 1973, after experiencing long waits at gasoline stations and being
informed in the Denver Post and the Rocky Mountain News in great detail about automated,
small-vehicle, nonstop, origin-to-destination service possible with the true PRT concept,
Denver citizens voted a one-half percent sales tax with the understanding that the result
would be the development of a PRT system for Denver.
Between 1970 and 1973, a group at the University of Minnesota, funded by the Minnesota
State Legislature, had been studying all of the PRT programs then underway throughout the
world. In December 1973 that group recommended that the Aerospace
Corporation work was the most promising and that a prototype of their system should be
tested at the Minnesota State Fairgrounds. In April 1974, after extensive hearings and
site visits, the Legislature passed an Act  that directed the Metropolitan Transit
Commission (MTC) to develop plans for a system that met the definition of PRT.
Conventional Rail Fights Back
The conventional rail community had expected that, under the UMTA Act, the federal
government would be handing out large sums of money to subsidize construction of
conventional rail transit systems in cities all across the country. To their dismay, the
promise of PRT generally, and the Aerospace system in particular, had stopped several
heavy rail proposals. Instead of recognizing the long-term advantages to their industry of
supporting the PRT initiatives, they felt that it was more in their interest to rid the
world of the competition of a new idea. In August 1974, as a result of heavy lobbying by
the suppliers and planners of conventional rail transit technology, the UMTA High-Capacity
PRT Program was turned into a harmless, poorly-funded research program that ultimately
died in the 1980's. Moreover, the design of the Morgantown system had been micro-managed
by UMTA engineers who did not understand the concept of PRT. The result was a system of
20-passenger vehicles running on an over-large guideway. It could never became a
commercially-marketable system and its high cost put a worldwide damper on the budding PRT
For its part, the Metropolitan Transit Commission (MTC) had strongly recommended that
an elevated, heavy rail system be built in the Twin Cities; nonetheless, pursuant to their
instructions from the Legislature they called for bids on development of a plan for a PRT
system. They received two bids: one from the Aerospace Corporation that reflected their
thorough work in PRT planning and design , and one from DeLeuw Cather, a transportation
consulting firm that, in addition to designing the BART system in San Francisco, had
vigorously opposed PRT in favor of conventional rail. The MTC picked DeLeuw Cather who
proceeded to develop a plan for a "PRT" system that used twenty-passenger
vehicles traveling on ten-foot-wide guideways. The economics of that design were
unfavorable, and, as a result, the Minnesota initiative died.
Meanwhile, the Denver plan was converted into a system of large, manually driven
vehicles running on rails in the street and obtaining power from an overhead wire. Such
systems had been renamed "light rail" (LRT). (Note: the Denver plan is discussed
in a book by Burke )
Since the demise of UMTA's early efforts, transportation consultants have advised city
planners to look only at "proven" systems. Because of today 's growing highway
congestion, the public has cried out that "we must do something;" and the
consultants, many of whom had lobbied against PRT, say repeatedly that that
"something" is either conventional heavy rail or, because heavy rail is so
dreadfully expensive to build, LRT, a modern version of the streetcar. What the
consultants are really saying, of course, is that they know how to design and build those
systems, never mind that they do not get enough people out of their automobiles to justify
either their huge capital costs or their continuing and substantial operating deficits.
Now that federal subsidies are beginning to dry up and people must put up their own
money to cover the capital and operating costs of conventional transit technology, the
picture is finally beginning to change, notwithstanding the lobbying efforts of the
suppliers of conventional transit technology and their consulting friends. People around
the world are once again looking seriously at PRT.
In the late 1980s, the leadership of the Northeastern Illinois Regional Transportation
Authority realized that they could not solve the transportation problems in the Chicago
Area with only conventional, or "proven," rail systems and more highways, and
that a new solution was badly needed. They became acquainted with PRT and, after
investigating widely, in April 1990 announced a program to develop a high-capacity PRT
system. After a bidding and preliminary-design process, the Raytheon Company ,
using designs developed at the University of Minnesota, was chosen to team with the RTA to
develop a prototype PRT system. Their work has now reached the test-track
stage, and the expectation is that they will have technology ready for deployment in
(Update: The test program was completed successfully, but shortly thereafter the
Raytheon Company terminated the PRT 2000 program due to a sharp cutback in the value of
its stock and other difficulties). It is now (2003) being carried forward by two
companies, one in Korea (www.prtkorea.com) and the other in the U.K. (www.yorkprt.com).
Stimulated by the Chicago initiative, planning and design studies for high-capacity
PRT systems have received governmental support in England and Sweden
, and private support in Korea . These studies posit
small-car, small-guideway designs similar to that developed at the University of
Minnesota. Together with new studies underway in the U.S. and in other countries, they
bear out the rationale underlying the Chicago project . Thus, it
looks as though the proponents of the status quo in transit technology may finally lose
their battle with the future. Conclusions reached in the new studies are most inspiring:
"PRT, after about four decades of study and some development, including over a
decade of relative neglect, should be moved back onto the public agenda for consideration
as one of the promising options for improving urban transit"
"Our recommendation is therefore clear. A PRT system provides such a broad range
of desired qualities that it should be given the highest priority in research,
development, testing and demonstration for implementation in the urban environment. Göram
Tegnér, TRANSEK, Sweden. 
"Advanced PRT systems provide a cost-effective and environmentally advantageous
solution to the problems of transport in the 21st century." Martin Lowson , Bristol University, England. 
"PRT technology offers the way to achieve our objectives while at the same time
offering enhanced urban form and improved lifestyle." Woobo
Enterprise , Inc., Seoul, Korea. 
"But even if the fuel consumption of cars is reduced by 50% in the 21st century,
they cannot compete with PRT." 
"Nationally, for well over two decades, PRT's efficiencies have been ignored
while hyper-costly and under-serving `light rail' trolleys have been standing in as the
highway's one rapid transit alternative, subways being non-competitive." 
1. William F. Hamilton and Dana K. Nance, "Systems Analysis of Urban
Transportation," Scientific American, 221:19-27(1969).
2. New York Times, January 21, 1972, page 1.
3. Hearings before a Subcommittee of the Committee on Appropriations, U.S. House of
Representatives, Ninety-third Congress, First Session, 1973, page 876.
4. An Act relating to metropolitan public transit; directing the metropolitan transit
commission to plan an automated small-vehicle fixed-guideway system; authorizing tax
levies upon property within the metropolitan transit taxing district. S.F.No. 2703,
Chapter No. 573, approved on April 11, 1974 by Governor Wendell R. Anderson. State of
Minnesota, State Capitol Building , St. Paul, Minnesota 55155.
5. "Personal Rapid Transit (PRT) : Another Option for Urban Transit?, Journal
of Advanced Transportation, 22(3):196-314(1988), a report prepared and endorsed
unanimously by 13 transit professionals.
6. Results of these and other studies will be published in a special issue of the John
Wiley journal Infrastructure, which is to be available in late April,1997.
7. Eva Gustavsson and Tomas Kĺberger, "Energy use in Personal Rapid Transit:
Building and running Personal Rapid Transit in Sweden," Journal of Advanced
8. Andrew Euston, FAIA, "Community Sustainability: Urbanization &
Infrastructure, Enterprise & Design," Office of Community Planning and
Development, U. S. Department of Housing and Urban Development, 31st Annual Federal
Workshop on Urban Environmental Design, Washington, D. C., February,1997.
Dr. J. Edward Anderson can be contacted at 5164 Rainer Pass NE, Fridley, Minnesota.
Fax: 612-586-0878; e-mail: email@example.com He
has also written a paper on the history of PRT which provides
additional detail and background on the topics and issues discussed here. His
most recent work can be seen at www.skywebexpress.com
(formerly know as Taxi 2000)
Last modified: March 19, 2004