Aug. 10, 2002 SolarQuest® iNet News Service
THE TRANSPORTATION RENAISSANCE
The Personal Rapid Transit Solution,
By Edmund W F Rydell
This long awaited exposition of the history of Personal Rapid Transit (PRT) had its inception when Ed Rydell suggested to Ed Anderson that a book for the general public was overdue. Never one to overlook a volunteer, Ed Anderson et al. accepted his suggestion warmly and assigned him the task to produce it.
Transportation beyond the horse and buggy stage consists of techniques invented over a century ago. The trend has been for larger and larger vehicles requiring more and more energy, producing more and more exhaust, taking more and more space, and outgrowing their early potential. A time existed when a train ride was exciting, a ride on a bus an adventure for grand-children, even when it was fun to drive a car.
Ed Rydell differentiates two modes of transit – personal and impersonal, the first the automobile and taxicab, but also bicycle, motorcycle, rickshaw, and even jitneys. Who remembers jitneys? They were 5 – 6 passenger automobiles with semi-flexible routes allowing more personal service than our current public transit. By 1917 it is estimated that 24,000 jitneys were profitably employed by their owners and entrepreneurs. Even then railroad interests had power and jitneys were outlawed.
Impersonal transportation modes are railroads, light rail (ne trolley or street car), busses, subways, monorails, and airliners. They have fixed routes, fixed times, are caught up in the traffic they seek to alleviate, and are so slow because of their frequent stops that most cannot afford the time to ride them. The final blow is they shut down at night.
Personal transportation seeks to fulfill the needs of the traveler, which is why the auto is so successful. Were public personal transit available it would relieve the traveler so that all he need do is announce his destination leaving the route to the mode to decide and relieving him of watching for his stop. His stop will be the only stop on Personal Rapid Transit.
He proposes a wish list : non-stop, user-friendly, no waiting, no standing, available always, accessible especially for the handicapped, secure, safe, no more expensive and probably less expensive than other modes, efficient and therefore non-polluting, silent, automatic, and low capital cost.
How does PRT perform meet all of these qualifications? That is what the book is about. He introduces the pioneers starting with Haltom in the early 50’s, who may have been the first to recognize that many small cars carry more riders than large cars and that off-line stations allowed non-stop trips.
His Monocab, suspended from an overhead guideway, carried six passengers, but switching was a problem. He sold his ideas to Vero, Inc. who built a test track. In 1971 they sold Monocab to the Rohr Corporation, who built a version demonstrated at Transpo 72 at Dulles Airport. It was selected for installation in Las Vegas. Mr. Rydell refers us to Catherine Burke’s Innovation and Public Policy who “dispassionately details the sordid involvement of government agencies as well as private vested interests.” “…The Urban Mass Transit Administration has done more to discourage than encourage innovative systems.” This was the first of several assassinations of attempts at building PRT.
Rohr persevered and tried magnetic levitation and introduced the linear induction motors. The latter was a huge advance, but mag lev appears to be better for interurban than intraurban transit – time will tell. Some simplified Rohr Monocab descendents exist in automatic industrial installations.
The Aerospace Corporation, a non-profit corporation established by the Air Force, did some of the best early work. In 1967 under Dr. Jack Irving, they came up with a revolutionary innovation for urban transit incorporating all of the major concepts of a true PRT design. A one-tenth scale model was built which proved that PRT was technically feasible. This led to the decision of the Nixon administration to build the Morgantown line between the Univ. of West Virginia campuses. Unfortunately UMTA excluded the Aerospace Corporation and finally turned it over to Boeing who had no prior experience or knowledge of the requisites. The Aerospace Corporation died of inanition.
Both Morgantown and Raytheon exemplified the difficulty arising from departing from the established theory of building PRT. They grew so that their guideways became prohibitive – e.g. the Morgantown system grew from work by William Alden who conceived the idea of an on-line switch that allowed cabs to run with very short headway because when the leading cab left the guideway into the station, the following cab was unaffected. (Traffic engineers advise that we should drive 2.2 seconds behind the car ahead. PRT now is designed at fractions of seconds between cabs.) He had started with a duo-mode car but realized the difficulties with it, and had changed to a closed system. His system was chosen, but the Jet Propulsion Laboratory of NASA was chosen to be the system manager, and they abandoned Alden’s system. Raytheon demurred, but Boeing became vehicle manufacturer, and Bendix made the control system with a headway of 15 seconds for its block system. Alden’s six passenger cars at 1.6 second intervals were replaced by cars seating 8 and with 12 standing at 15 second intervals. The guideway was U-shaped, could not be plowed in a snow storm, and therefore the snow must be melted; it requires four times as much energy to melt the snow as to propel the cars. Harris Engineering designed the guideway, but the change in size of the cars made them not fit into their track, so hasty alterations were necessary -–it reminds one of the definition of a camel as being a horse designed by a committee.
Well, it has worked for thirty years, so who’s complaining. It’s just that wouldn’t it have been something were it PRT.
The second half of the book tells of the development intellectually of the engineering using computers, automatic controls, guideways with supports only 60 and maybe 90 feet apart, and headways between cabs of 0.5 and perhaps 0.25 seconds. The exciting potential is spellbinding, but reviewers of books shouldn’t spoil the ending for the prospective readers.
The Transportation Renaissance can be purchased at your local independent book store or directly from the Xlibris Corporation at 1-888-7-XLIBRIS or at www.Xlibris.com – 4326-RYDE. It is available in hard cover or paper-back.