Should Dualmode Concepts Give Priority to Intercity Travel or Intrametropolitan Travel Problems?

by Jim Haugen, with a response from Bill Turnbull

Questions have been raised regarding the validity of Jim Haugen's view that Dualmode concepts
should give priority to dealing  with intercity travel rather than intraurban travel problems. Here's his response, followed by a commentary from Bill Turnbull.

1. General - For 30 some years I have seen, over and over again, nice
conceptual drawings of new systems overhead structures, with just a few
vehicles on-board, located in a pristine, park-like setting; or,
alternatively, a similar system running down the median of a freeway. Either
way, the purpose is supposedly to convince viewers that such a system will be
unobtrusive when installed. Dualmode proponents must be realistic about the huge
problems of fitting such systems into an urban setting, such as those

2. Freeways

2.1 Physical constraints

Response from Bill Turnbull

I have no serious disagreement with most of what Mr. Haugen has to say. There are difficulties, serious difficulties, associated with implementing any urban transit system, dualmode included.  I have no quarrel with that. Nevertheless, it is precisely in the great urban areas where the major problems exists.  I don't think we can walk away from that.  The problem of inter-city travel may well be approaching a crisis - the crisis of intra-urban travel is here and now.

Studies suggest that the capacity of the Los Angeles freeway system will have to be doubled in the next five decades.  It is in this context that we must view the difficulties Mr. Haugen describes.  That is, in a comparison of the relative difficulty of competing means to achieve our goals, rather than simply some absolute recitation of the obstacles.

A single dualmode line has the potential to accommodate several lanes of freeway traffic; perhaps as many as six to eight.  Implementing dual mode is not without its problems; but then, so is providing six to eight more freeway lanes.  I think it is not an unreasonable argument that a single dualmode line might be considerably less expensive than 6 to 8 freeway lanes.

I look upon the initial implementation of urban dualmode as primarily an adjunct to freeways.  And yes, I would anticipate using the median where available; and, if necessary, usurping an existing freeway lane.  The problems Mr. Haugen lists such as the requirement for under and overpasses (flyovers), merge lines, interchanges, and the necessity of separating transit vehicles from other traffic are real and must be addressed. However, I do not see these as insurmountable.  Moreover, they are not new issues to serious students of this topic.

I differ from most of my colleagues in that the pursuit of the latter requirement(separation) mandates an elevated guideway.  This may well be a requirement in many instances. To require it in all instances, without regard to specific local conditions, places an undue economic burden on any system.  We must guard against imposing any requirement arbitrarily, to be applied universally.

On one issue, I am afraid that I must disagree with Mr. Haugen completely. In his previous submission, he discusses the difficulties of installing an urban system (as he has more fully here) and then informs us that ". . . the potential service gains are, at best, trivial."

I can't imagine that a commuter stuck in freeway traffic at 15 to 20 MPH (or less) would agree that proceeding at 80 MPH (or some such number) in a hands-free, hassle-free, direct to his destination journey would constitute only a trivial improvement.  The use of electrical propulsion, thus greatly minimizing the concentration of automotive pollutants, would also seem somewhat greater than trivial. These are only two of the most important; there are others that have been discussed extensively in these and other proceedings.  Indeed, Mr. Haugen list some as they apply to inter-city travel.  They apply to urban travel as well.

In the final analysis, economics will prevail.  If, in the pursuit of solutions to our many and urgent urban transit problems, a dualmode system proves (as I believe it will) to be the economic system of choice; then the many other advantages will prevail over political objections.  This may be wishful thinking; but I, for one, believe it deserves one hell of a try.

In this connection, much was made of faulty (and over optimistic) economic projections; e.g., guideway cost per mile with little or no consideration of other costs.  While that may have been true, I see no need to continue the practice.  Estimates must be developed that describe the true costs (as best as can be determined) of a specific project, not some general considerations.  No one is served by a low-ball estimate that ultimately results in a cancellation of the project (for instance, Seattle).

I guess what strikes me most about Mr. Haugen's discussion is the overriding pessimism.  No one suggests that his very real concerns should be ignored; but perhaps, a small measure of excitement over the opportunity-to-excel might also be in order.  He does, however, offer hope.  He indicated  that he has some ideas "(biases?)" that might overcome these concerns.  I look forward, enthusiastically, to considering them.


Last modified: July 14, 2001