Reactions to National Integrated Dualmode System Critique by Dr. John Hopkins


William Bowen

May, 2000

William Bowen is working on a dualmode concept called Autobus. While there is no website devoted to a descripton of this concept, it is similar in many respects to the VMTS/Carbus webpage at the ITT website. Reviewing it would be helpful to an understanding of Bowen's response as presented below.

I agree that Dr. John Hopkins raises points that alternative transportation systems developers ignore only at their extreme peril.  The parts of his letter that describe real-life institutional and market constraints are instructive; and, I believe, accurate for the most part.  You pose the question, if he is right, "... what is the point of continuing to pursue dual mode?"

I found that a good deal of what he says supports the autobus dual mode case.  Furthermore, nothing said  raises a "deal killer" issue for autobus

My comments on his e-mail, and how it relates to autobus, are interlineated below.

Dr. Hopkins states:

Much of the thinking about innovative transportation technologies in the latter half of the 20th century has been devoted to systems that embody a tight integration between vehicles and guideways, often also including the control system.

The foregoing does not apply to autobus/carbus type systems.

In contrast, it can be argued that one major reasons for the dominance of traditional aviation, highway and rail technologies is their adaptability.  Within relatively modest bounds, any road vehicle can operate anywhere in the highway system.  Similarly for intercity and urban rail systems.  Vehicles and proulsion have changed, roads and track have changed, control system technologies have changed.  But throughout, each change has-to a remarkably large degree-been independent of the others.  More importantly,
improvements have been substantially "downward compatible,"  with new roads readily carrying old cars and trucks, and the newest vehicles operating successfully on highways constructed many decades earlier.

I agree with Dr. Hopkins on this point.  It is also a strength of the autobus system.  autobus will carry almost any standard production passenger vehicle ranging in size from Geo Metro to GM suburban without any modification whatsoever to the client vehicle.  There are only a few exceptions.  Our current design would not accommodate a Ford Excursion.  Similarly we would not carry  one of the three 15 passenger vans (Ford, Dodge or GM).  One of them is slightly more than 7 feet in height which exceeds our maximum by about 3 inches.  No special vehicles are required.

Thus the autobus dual mode transporters and our client vehicles operate on the highway system.  However, as a practical matter, we would need a portion of the capacity of a segregated, standard freeway lane.  Any HOV lane would do.  So I do not believe our requirement violates the constraint Dr. Hopkins describes.  Similarly, autobus rail transporters could operate on any available standard gauge rail line.  So, autobus is both adaptable and downward compatible.  

...In contrast, it can be argued that one major reasons for the dominance of traditional aviation, highway and rail technologies is their adaptability.  ...A key point is that these [highway and rail] systems have thus been able to evolve, adapt to changing needs, and incorporate technological advances in a basically incremental fashion.

We regard autobus as an incremental improvement to and an adaptation of the highway/automobile system.  Again, we agree with Dr. Hopkins; and we believe his point supports our case.   PRT advocates in this forum have criticized this aspect of the autobus system concept.  Apparently, we are not sufficiently revolutionary for their tastes.

 In a world characterized by rapid technical change, but also in which infrastructure and vehicle lifetimes can be many  decades, as can the time required for initial construction, this consideration becomes ever more important, since it is highly desirable to minimize the impediments to introducing beneficial changes (and the costs) wherever they arise.  A related factor is the reality of very long implementation times for physical infrastructure, which must therefore accomodate vehicle and control technologies that will inevitably change substantially before the system is even finished, to say nothing of the duration of its service life.  System economics are also affected, since infrastructure-dependent benefits will emerge only slowly, thereby reducing the motivation of vehicle owners to pay for the related vehicle technology that will offer very limited initial return.  Further, the decision process for shaping system evolution becomes very complicated.

With due respect to Dr. Hopkins, it seems to me that while his observations are correct, his thinking is muddled on the foregoing points. The reality of long implementation times is a reflection of a USDOT bureaucracy that has effectively zero ability to innovate, and has even less capability to support and foster independent innovation.  (Less than zero capability is in fact possible in this arena.)   The "decision process for shaping system evolution" is corrupt and intellectually dishonest, starting with the originating agencies (state DOT's and transit agencies) passing through consulting houses of ill repute, and on into USDOT's program administrations (FTA and FHWA).   The politics of pork drive the entire process.  Innovation and technological merit are, at best, transitory afterthoughts.

Seed money and a conceptual framework can be provided in a top down manner,

The advocates of alternative transportation systems would be delighted if this were done by USDOT.  A great deal could be accomplished with relatively modest sums.  A fraction of what USDOT poured into the ground in Los Angeles would be more than adequate.

The high capacity which should be a strength of HiLoMag will typically not be matched in urban areas by the ability of local roads to handle the traffic generated-the bottlenecks will simply to moved around, not eliminated.

Without comment upon or reference to HiLoMag specifically, we agree in general with Dr. Hopkins' point.  Any system that just moves bottlenecks around is no solution.  autobus is designed to eliminate freeway bottlenecks.  Nothing more.  Nothing less.  We are convinced that there are enough of these on suburban freeways around the country to make what we are proposing a viable, but quite specific solution.  If there are zones of persistent congestion on a freeway system with free-flow conditions someplace upstream and someplace downstream of the congested zone, autobus becomes a candidate solution.

...And if you really think about the many ways and places that cars are used, it would seem that most people would continue to want to have the functional equivalent of current vehicles, and a very large network of conventional roads would still be required.

We agree.  autobus complements the existing "very large network of conventional roads", and preserves and enhances the functionality of current vehicles.

Dr. Hopkins is obviously a very thoughtful person who brings a great deal of experience and expertise (as well as impeccable credentials) to the discussion.  I would challenge him to bring his considerable personal  resources to bear on changing the climate for innovation at Volpe and at USDOT in general.  As a former executive of a university-based, NSF-funded innovation center, I feel qualified to state that at USDOT innovation exists, hardly at all as a matter of fact, but primarily in feel good phrases found in senior political appointees' self-laudatory statements.


Last modified: May 16, 2000