I have read the items posted on the PRT Debate page and would like to offer my views on the issues raised.
I have been aware of, and am a student of, the work of these three transportation planning and engineering giants for decades--beginning with reading their works in graduate school and until this day. In the 1970's I was in Dr. Vuchic's camp. I loved streetcars and train with a passion--energy and land efficient modes with little pollution per passenger. I was convinced that light, heavy, and commuter rail were the salvation of our cities (along with electric cars and other road vehicles burning clean fuels). I signed on with the planning department of the Chicago RTA when I completed my Ph.D. on the subject.
Then I had the good fortune to meet Dr. Anderson sometime while I was researching energy efficient transportation technologies for the U.S. DOE at Argonne National Laboratory. He convinced me that PRT was not a fringe technology but a concept with considerable merit. But I must admit, I still cannot visualize it as being used for city-wide networks, as he and others do.
Jerry Schneider and I have crossed paths professionally many times and now interact often on the Internet. Thus, because of this history, I find their point/counterpoint in the above mentioned articles quite interesting.
Vukan will be a rail advocate until the day he dies, and probably death will not slow him down since I expect I will find the ride through the pearly gates will be on LRT. Ed, a most-gifted conceptual engineer, has developed the PRT concept in micro-detail. I suggest you read his piece on the PRT debate page where he totally destroys Vukan's arguments. Ed is not the father of PRT, but he certainly is the godfather. Jerry is more balanced, but listing heavily toward PRT.
The LRT systems we have built in this country in recent decades range from moderately successful to near disasters as the ridership and farebox recovery data make it obvious. The lack of true success is due to three main factors:
--1) To save on capital costs, existing rights-of-way (often freight rail lines or freeway medians) were used where ever possible. Thus many stations are in less than optimally accessible locations (i.e., not where trip origins and destinations are).
--2) Even if the station were optimally located, a rail system serves a finite number of points called stations, and stations are often surrounded by parking lots instead of ridership generators.
--3) In moderate sized cities where recent LRT systems have been built, for most trips it is still more convenient and faster to drive. And contrary to popular belief, the road construction option to sustain driving is still highly funded.
So in my analysis of the urban transportation situation who is right, Vukan or Ed and Jerry? I think that each transportation need has to be analyzed and the proper mode chosen to meet the need in the timeframe required with minimal use of land, oil, and other valuable resources such as clean air. Doubtless, all three would agree with me. But that their analyses of what is "proper" in a given situation would differ, I am also sure.
The current and planned expansion of the light rail system in San Francisco makes sense to me; as does testing the PRT concept in Rosemont; as will significantly increasing access and egress to and from our existing rail, ferry, and express bus lines with station cars; as does the monorail connection of Newark Airport with the Northeast Corridor commuter and intercity train service; and as will dual mode in urban regions with no line-haul transit. Permit me to mention why.
In San Francisco the commuter rail line up the peninsula terminates short of the downtown. The politicians have never been, and may never be, able to agree on how to bring the line downtown. So extending the LRT to it makes sense as a second best alternative. Extending the surface streetcars to Fisherman's Wharf also makes sense from historical, tourist, and transportation viewpoints.
Rosemont is the perfect place to test the PRT concept. It is an unattractive (i.e., no potential aesthetic impacts) mid-rise, suburban, commercial development (office, restaurant, hotel, and convention center). The PRT will provide for internal circulation and also provide a feeder service to the CTA's rapid transit line.
When 80% (a BART number, but generalizable) of detraining riders walk to their destinations, rail transit is not serving much area on the destination end of the trip. Station cars can expand this area significantly, especially for reverse commutes. A significant number of commuters say they don't ride transit because they need their car during the day (17% of the 425,000 who could ride BART reported this reason first for not riding). The solution in many cases will be station cars. Yes, PRT could serve this demand, but when will it be available?
The lack of a good Newark Airport to NE Corridor connection has been an obvious gap for years. PRT advocates might argue that PRT would have been a better choice, but monorail was an off-the-shelf technology ready to meet the transportation need.
I recently studied a major commute traffic problem on I-10 freeway west of downtown Houston. I found that a dual mode solution makes sense. The rail right-of-way paralleling the freeway has been publicly acquired. A dual mode guideway system in/above that RoW and above the freeway median for certain segments is a logical first step in a dual mode network approximating Houston's ring-and-spoke freeway system. Electric cars would connect origins and destinations via local streets, but would use the dual mode guideway network for the line-haul. In a sense, this is a variation on the station car concept for urban areas without existing line-haul system. Could PRT do this? Yes, but with many more miles of guideway duplicating perfectly good local streets and many years later.
While we all agree that an analysis of appropriate alternatives is required for each application, I think there are some rules of thumb as to where each mode of transportation discussed above is most appropriate.
Urban rail systems are most appropriate where you have heavy bi-directional flows not served well via automobile or bus for many hours each day or where there are rail networks, such as in New York City. Thus they are not appropriate in most U.S. cities.
For at least the near term, PRT is appropriate for areas up to several square miles with a many-to-many (very dispersed) trip pattern. Urban campuses, such as the University of Illinois, Chicago, where the guideway will not be obtrusive, come to mind as a good place to start. The University of Minnesota in Minneapolis is, for example, too architecturally sensitive for an early system. But, dense suburban activity areas (such as Rosemont) that are bifurcated by an expressway that makes walking impossible, are appropriate.
--Station cars are appropriate for most existing urban rail stations and other urban places needing high regular access.
--Dual-mode will serve urban areas with no or little line-haul transit and very dispersed origins and destinations as Houston.
--Automated people movers (including monorails) can work well in confined areas with many-to-few origin-to-destination trips, such as amusement parks and airports.
Martin J. Bernard III is the Executive Director of the National Station Car Association. He lives and works in Oakland, California. The station car Web site may be seen at:
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Last modified: January 3, 1997