Dualmode-PRT Design Considerations


Walt Velona

August 24, 2000

It has been a pleasure to read the material describing your Dualmode and PRT systems. I know how much dreaming, how many sleepless nights, how many hours of hard work have gone into the creation of your individual proposals. In my view you people are the first unsung heros of the 21st century and I hope you will all be justly recognized and rewarded. May all of you remain at the forefront of this transportation revolution and become its principal builders, manufacturers, and operators. I have no wish to critique any of your work. Rather I will simply pass along a few thoughts and let you draw your own conclusions. You will note that my concerns deal more with transportation demand, transportation productivity and our ability to sell the new technology. I hope my contribution will help you to pinpoint what comes next.

I feel that now is time to reach agreement on the design of the guideway. The nation can begin building thousands of miles of guideway before the tests on the new vehicles and other concepts are completed. My hope is that all of you agree that there can be only one guideway design. Just as roads are the same for all, so will the guideways be the same for all. Traffic on the guideway will be like traffic on our roads. Thousands of businesses provide transportation service on our roads. The same process should occur on our guideways. Once the guideway configuration is selected, the question for each of you is "how can I adapt my ideas and my patents to this design?" The debate to date has focused on the defense of your own designs. I think that now, it is time to step back and broaden your view. It would be a feather in your collective caps if the agreed upon guideway design were to be presented at the Dualmode Professional Engineers Conference in October.

I wish I could say that I am totally unbiased. I cannot. I am biased toward the use of magnetic levitation. Logic, or maybe instinct, tells me that maglev is an enormous gift to mankind that must not be ignored. It represents the elimination of friction, of wear and tear, of costly maintenance, a major component of the cost equation. In economic terms it may represent one of the largest boosts in productivity ever contributed to our society by any individual invention.

When we go to the President to offer our Dualmode, one of our arguments is that we have not only doubled the life expectancy of our automobiles, our existing highways, and also the new guideways, but that we have cut our automotive maintenance bill by half. Automobiles will not wear out so quickly. They are perfectly still on the guideway, while they travel thousands of miles. Their engines and their tires will last longer. There will be few if any eighteen-wheelers to pound our highways. There are no wheels to pound the guideway. There is no frictional wear on the guideways.

All of this represents a productivity increase. We lose the benefit of this argument however, if the wheels of the auto are replaced by the wheels of the guideway. It is my hope that all of you can easily convert your proprietary wheeled systems to maglev without seriously compromising all other features of your designs.

Our single most important national objective is to quickly convince our nation to buy electric cars. As I see it, no one incentive will provide greater motivation to buy electric cars than the ability to enter a high speed guideway quickly without stopping. This is why I am absolutely convinced that the pallet must be an integral part of the electric automobile. Admittedly this will increase the cost of the auto, but perhaps under mass production its costs should be much less than ICE cars of today. It is also possible that the pallet can be a separate module that attaches to autos, and that its life time will outlast that of the auto.

I suggest that as soon as the cars enter the guideway approach lane, they are checked while in motion for credit and performance and if found wanting, they are diverted to an exit. If accepted, their engine is cut off automatically and they enter the final approach on the guideway. All that is needed is the design of an interface between electric cars and the guideway that accomplishes these functions.

I further suggest, that entrances for other vehicles, including those needing external pallets, be provided only at other and less frequent locations. I assume these latter stations will have to be manned and their numbers should be kept to a minimum. I can think of no better way to convert our nation to electricity than to give them the option of choosing between these two types of entrances unto the guideway. The electric car market will boom.

The idea of a 200 mile an hour Intercity Dualmode Guideway System is also highly attractive. However, the choice of system velocity will require careful study. More people will be attracted to the guideway as more speed is offered. But as speed rises so does the price. As price rises fewer people are attracted. At some point a particular combination of speed and price produces the maximum revenues.

This is the velocity we should use if we operate the system strictly for the operator’s profit.

However this may be one of those cases when the function of the market mechanism does not capture all the benefits of the country as a whole. Velocity not only benefits the user but also benefit other elements of our society that are not using the guideway and are not subject to its pricing structure. In essence they are getting a free benefit. I am guessing that the velocity that produces the maximum revenues, will be lower than the velocity that produces the maximum long term productivity for the nation. If I am correct, then we should adopt the faster system. However, the user should not pay the added electricity costs of the additional velocity. The added velocity was introduced to benefit the nation and should be paid by the nation by whatever fiscal tools are appropriate. Not only does the nation achieve its additional gains, but the added component of velocity shifts the demand function upward and increases usage thus furthering our goal of converting to a new energy source. That alone has side effects that benefit the nation, users and nonuser. Studies are required to give substance to my guess.

However I realize that the paying of operating costs by nonusers will be anathema to many. In that case we can use the solution suggested by Guadagno. We will build a slower system and a faster system. Let us build a 200 mile an hour 42,000 mile system generally along the Interstate Highway system Corridor. Then let us build 8,000 miles of a 300 mile an hour system that connects the distant parts of the country. The operating speed on the 42,000 mile system would be set at 120 miles per hour or whatever speed generated the maximum revenues. The operating velocity on the 8,000 mile system would be set at 240 miles per hour or whatever velocity generated the maximum revenues. Users could opt to travel the entire trip on one of the systems or a combination of both. Together the two systems should be able to capture most of the potential benefit for the country that speed can achieve.

The speed question has another interesting dimension called capacity. Our guideway is unique in that increases in velocity increase its capacity. I assume that the system velocity can be changed at will. (Am I right about this?) Thus as the guideways become congested, the congestion can be relieved by increasing the velocity. The importance of this fact is that it tells us that we should design for a higher velocity than the finally adopted system velocity. If a 200 mile an hour system is technically possible, then this is the system to build, even though we intend to operate at 120 miles per hour.

I have read the pro and con arguments for supported versus suspended vehicles and pallets and I am not sure that I have anything constructive to offer. At the moment I still favor the supported vehicle. My principal reason is that in case of a shutdown, wheels will be needed to support both the cars and the pallets. I have already argued that maglev is superior because wheels are not needed while in transit. I have to concede that wheels are needed if the guideway shuts down. My concern is that I cannot see putting wheels on a pallet mounted on top of the electric cars. My fears may be unfounded. Perhaps small diameter rollers could be placed next to the magnets. It seems to me that we should take advantage of the fact that the electric car already has wheels which will support the car and can also be used to drive off the guideway under its own power. Perhaps cars with their own pallets should ride in top of the guideway and pallets carrying cars and containers should be suspended on the guideway. Perhaps the guideway should be protected with a roof and partially open transparent sides. Then all traffic would be under partial cover.

I have one final thought. I suggest to you that the best way to become involved in the new Dualmode-PRT industry is to be involved at its beginning. This is your project. Fight for it. I believe that all of you, together should brief the next President of the United States. I have a few ideas as to what the briefing should say and I will pass them on to you, hopefully through the good graces of Jerry Schneider. But, as soon as possible you should invite urban and regional planners, transportation specialists, economists, environmental engineers, petroleum engineers and electric power engineers to this debate. Your briefings to the President and the Congress will need their input.

I have already prepared a draft of a letter to the President which I will forward to Jerry in the next few days. I will ask him to pass it along to all of you for review, revision, editing and approval. All of us should sign the letter. We have earned the right. That will be pretty much the end of my contribution to this effort. (Although later on, I may send you some numbers that might be useful in preparing the briefing.)


Last modified: August 24, 2000