Our National Dualmode Transportation System

By Francis Reynolds

David Gow quoted from Dual Mode, the Transportation of the Future, published in The Futurist magazine, September 2001 issue:

We will have even more private cars, yet we will avoid the problems we now have-- by using our cars in two distinct modes. The cars may be standard or specialized, depending upon the details of the system. They will be driven in the normal manner on the streets, and they will travel automatically on high-speed dedicated guideways-but their drivers won't be driving. Trips of more than several miles will be on these guideways rather than on the highways. A dualmode system will be even more "personal" than "Personal Rapid Transit," since we will be using our own cars. And it will also be more "rapid," than PRT since we won't have to walk to and from stations. We will travel from door to door as we now do, without getting out of our cars, but we will travel safer, cheaper, faster, with less stress, and with neither gasoline nor pollution.

Gow, in responding to the above, spoke of "the irresistible attractiveness of the private automobile"—then he proceeded to resist the irresistible. Good luck, David! You may be able to resist using your personal automobile, but neither you nor any other single or group of transportation reformers will succeed in reducing the number of vehicles worldwide. Private cars provide the most convenient, fastest, flexible, and most satisfying ground transportation known to mankind; and few of their owners and future owners will give them up. The beautiful fact is that we won't have to, yet transportation in the future will be much better than it is now.

The thing we do not know is when this transportation revolution will come about. It should have started a few decades ago, but unfortunately crises are required in order to motivate us as a society. Our transportation and environmental pains weren't serious enough earlier.

It has been pointed out that traffic is self-limiting. It will grow to fill the available or expanded roadways and then it will remain at a level that is just tolerable to some drivers but intolerable to others. Does this mean we should give up and build no more streets and highways? Certainly not. We should add more transportation capacity of kinds that will best satisfy the majority of commuters and travelers. And this added capacity needs to be of types that will minimize rather than worsen our serious air quality, global warming, and petroleum-depletion problems. It cannot be mainly PRT or any other form of transit, because the majority of people in most areas no longer use and will never again go back to using transit. Most forms of transit lost the major part of their markets fifty or more years ago when the automobile largely replaced them. Those who think that PRT will make transit popular enough to replace a high percentage of private cars are kidding themselves. PRT would offer privacy, and a few other advantages over existing transit systems, but it falls far short of being able to do the overall revolutionary job that our present situation demands.

Current pressures dictate that we must add more highway lanes and repair the bridges and potholes. In some areas we may need to add more buses, but in many areas the buses run nearly empty a high percentage of the time. There are no other intelligent near-term choices. By far the most logical long-term solution is a standardized national and international dualmode system. Here I would much prefer the word "immediate" rather than "long term," but we can all see that getting a national dualmode system designed, approved, financed, and built is going to take decades longer than we would like it to—dangerously longer—but there is no satisfactory alternative.

It must be an all-encompassing national dualmode system that will allow continuous trips, not just within a city and its suburbs, but from any city to any other city, or across the country. We can now stay on the same train or the same airplane for long trips. And our city streets smoothly join our highways so they do not force us to change from one vehicle to another at any time. It would make no sense to design a revolutionary future transportation system that would regress to the inconveniences and time loss of changing vehicles during a single trip.

Someone wrote that he didn't like private cars. Fine: I don't expect that person to drive one, but he should not try to take cars away from those of us who choose to use them. The things that are now wrong in the use of cars have developed because of their huge success and popularity. The automobile was invented when traffic wasn't much of a problem, most of the petroleum was still in the ground, and the words "pollution" and "global warming" were not in the news. There is nothing basically wrong with the concept of private vehicles, but the ones we now have are outdated because things have changed greatly since Benz, Daimler, Ford, and others invented these wonderful contraptions.

All inventions have a finite life span. The kerosene lamp and gaslights are all but gone, and in turn the incandescent light has lost much ground to fluorescent lights. Now it is beginning to lose still more to high-intensity LED's. It is time for a major redesign of our private vehicle system—redesign, not eliminate. It is a big mistake to assume that the concept of private vehicles is wrong just because the system we now have has become saturated. And this is a system problem; we can't work it from the standpoint of the vehicles only, or from the standpoint of the roads or guideways only. We must think big and consider all aspects if we are to come anywhere near to an optimum solution. One of those "aspects" is air transportation. The only energy sources we have for airplanes are liquid hydrocarbon fuels, and the world's petroleum resources are nearly gone. Long extension cords to power electric airplanes haven't proven to be practicable.

Very fortunately for civilization, it turns out that the right kind of dualmode system will solve or greatly reduce the severity of a surprising number of our transportation, environmental, and energy problems; a far greater number than most of us who have invented and worked upon this concept initially envisioned. For instance, maglev dualmode guideways between cities and across countries and continents might operate in the range of 200-mph (325-kph). This is a compromise between needed speed and excessive aerodynamic drag.

At such speeds the dualmode guideways would be faster than air travel for distances up to at least a thousand miles when one considers all of the non-air-time expenditures associated with flying. Dualmode will reduce air travel by a large factor as soon as it is available. And if we take our own car on the guideways we will have it to use at our destination, rather than a rental. If we fail to find a way to power airplanes without petroleum the guideways may have to take over all domestic air travel. By eliminating most of the drag, evacuated-tube guideway transportation could be far faster than existing airplanes for trips of any length; and run without petroleum and without weather problems.

Note that a dualmode system should not designed to establish or enforce public policy, any more than the streets and highways do. That is, our street and highway system accepts a huge range of legal vehicle types. As long as they obey the traffic laws and meet certain requirements such as turn signals, lights, and limits on weight and size; SUV's, motorcycles, VW Beatles, transit buses, and semi trucks may all use these facilities. Some of them may not be popular with certain other classes of travelers, but the prohibition of any class of vehicle is a matter for the politicians, the polling places, and the courts. So it must also be on the dualmode guideways.

It appears at this point that the guideway limits on vehicle size and weight will end up lower than those on the highways, but again those limits will be determined by due process during the design-phase of the national guideway system. They must not be established by some engineer's personal preferences or environmental convictions. Once built we could by law, if we wish, restrict the guideways to private vehicles only, transit only, or to freight only, or we can leave them open to all vehicle that meet the system requirements. In my mind the latter is the way it should be since multiuse will solve far more transportation problems than any single use of the guideways would.

But back to the Dualmode-Debate contributions of David S. Gow: In his My Misgivings—an Essay of 7/26/02 David gave us a chart titled My Issues with dualmode, which I will respond to below. Where I quote him I will use Italics. Mr. Gow is obviously an intelligent person, and most of his "misgivings" stem from insufficient exposure to some of the dualmode proposals that are being made. On 7/30, he entered another item titled Dual Mode Debate: Where's the public transit? That question is easy: The public transit will be an integral part of the dualmode system.

I will address that question in detail, and others in this second debate after addressing his misgivings of 7/26. Thank you for speaking up, David. Obviously dualmode transportation has not been as well understood, even to most students of advanced transportation, as many of us thought it was. Thanks for the opportunity to elaborate. Yes, there have been many types of dualmode systems proposed. These include both good ones and bad ones. The following will be based upon the type of comprehensive national dualmode system that I envision. I automatically like all people who like dualmode, but I take issue with all of them who want to emasculate this grand concept down to a "low-cost" thing that would fall far short of solving all of the problems that a proper dualmode system can and should be equipped to solve. Dualmode-guideway cost will be a political football, but it will not be an actual problem, because of the tremendous market (mostly private) there will be for guideway use. A cheap system might cost twenty-five percent less, but might attract fifty percent fewer customers. Poor economics.

David Gow wrote:

Dual Mode guideway would have to be over-engineered to allow for weight of the largest passenger vehicles.

Things should not be "over-engineered," they should be well engineered and designed with adequate capacity for a specified job. We do not need to decide at this point what maximum size of vehicle should be accommodated on the guideways. But since our national dualmode system should carry fast freight, and transit buses of reasonable capacity, the size and weight limits on the guideways will probably be larger than the largest private passenger vehicles.

A weight limit would require installation of scales at all access points, not to mention reduce the system's appeal.

With freight, light trucks, and buses larger than the largest private cars, the cars would not have to be weighed. Where weighing is required it will be done automatically during the few seconds that other entry processing is taking place.

It appears people will be expected to buy a new Dual Mode-compatible car.

Practically all of our existing cars will be worn out by the time we have a dualmode system. During the transition period, when just part of the guideways are available, our cars will still need internal combustion engines (if there is any gasoline left by then) since battery or fuel-cell cars are inadequate for highway use. New cars built during this interim period can be conventional and can use the guideways with pallets. Or they can be true dualmode: equipped for travelling on the guideways directly as well as on the streets and highways. When the guideways are largely complete most people will naturally start buying all-electric true-dualmode cars. Those who live many miles from the nearest guideway, or who use an automobile for certain types of recreation, will still need a conventional car, or need to rent one (again if there is affordable gas for them).

This means the guideway must be engineered to carry heavy, large-capacity vehicles and their cargoes. This means more time-consuming construction, more materials, and higher costs compared to PRT.

Yes; all of the above. This also means that we will have a system that will largely replace our highway system by carrying most of our surface vehicles, far faster, greener, and safer than they are now driven. By comparison PRT would be a waste of time and money because it would solve or reduce few of our many major transportation and transportation-related problems.

Over 95% of all passenger miles in the U.S. average less than 2 occupants per vehicle.

Very true, and neither you or I are going to change that significantly, because that is the way people want to travel. PRT would let us (make that "them," because I don't care to use it) continue to have only one or two occupants per vehicle, but it would make people walk in the rain and cold, or use their car to get to the PRT station. The percentage of people using PRT would be disappointing; the same as it has been on all other forms of transit since the wonderful automobile took over.

Will dualmode cars be widely produced by the automobile industry? Will the guideway manufacturer also build cars? How much capital does it take to set up an automobile manufacturing business?

Yes they will, by the millions, but they don't know it yet. The guideway organizations will not build cars; highway organizations don't build cars either. And Bonneville Power doesn't make toasters, but toasters have to be designed to use standard power. No new car companies will be required, but it will cost hundreds of millions to design and retool automobile plants to make dualmode cars. This is something they can handle; they do it every time they put out a significantly changed new model.

Why does Dual Mode bother to mimic trains by proposing the option of linking cars together into trains?

There is no need to or desire to mimic trains, and I do not wish to physically link cars together. However, running cars closely together in platoons will markedly reduce aerodynamic drag. And in a Linear-Synchronous-Motor (LSM) guideway system such as I propose, a certain type of platooning will also reduce the number of ramps required at heavy-traffic exits.

Zero headway would maximize the number of vehicles that could be handled per unit of time, but really-- how many people travel from exactly Point A to exactly Point B, at the same exact time? A disincentive of trains is the need for riders to gather together at designated locations & times and travel with others-- PRT recognizes this disincentive, does Dual Mode?

Yes indeed. In an LSM maglev dualmode guideway system, cars will travel in the order of one foot apart, yet any car from anywhere in such platoons will be able to exit at any point without slowing or otherwise disturbing other cars in the platoon. Any car in a string of cars on a highway can now exit at full speed without disturbing the others. It will be just as easy on the automatic guideways.

A person might find his Dual Mode car confined to the pavement if traveling to/through an area with an incompatible system. A national or continental Dual Mode Standard would be needed to avoid this. Good luck.

Precisely. A standardized national and international dualmode system is the only way to go. I envision seamless dualmode trips from Alaska to Brazil, and from Norway to South Africa. Good luck will help, but mostly it will take a heck of a lot of hard work by thousands of people. I think it will happen, but "When?" is the question that worries me. Every additional year will cause increasingly serious crises in traffic, fuel-depletion, global warming, and other pollution.

Talking about parking garages. … … It's a good bet they won't be free.

No, they won't be free. But that is good, because most things that are "free" actually cost us more than they would if we visibly paid for them. David brought up a number of valid points on the subject of parking. This article is getting too long, so I won't take the space to try to answer them in detail here. But the flexibility of a wisely planned dualmode system will make it possible to reduce overall parking problems. Park and ride lots will disappear for one thing. Parking at central final destinations will require less space than it now does, because automatic parking directly from the guideways will require considerably less volume per vehicle. These automatic parking systems will be private enterprise, just as parking garages off of the streets are private, not part of the guideway system.

Perhaps my biggest problem with Dual Mode is that it is not mass transit for the public, but rather private transportation that achieves high volume through automation.

David seems to suffer from the false modern thinking and teaching that "Private cars are bad so we must get rid of them; and that transit is good, so we must have more of it." I ask where we can see an example of transit of any kind having significantly solved traffic and related problems in any area that has suffered from them. Transportation problems everywhere continue to get worse, except for temporary reprieves when new lanes of highway are opened. There is nothing wrong with "private transportation that achieves high volume through automation." In my book that is exactly what we need. As to "mass transit for the public" there will be all of the dualmode transit that there is a market for, and it will be much faster than present single-mode transit.

Under Dual Mode, "why don't more people take mass transit so I can use the Dual Mode guideway?" could become a common refrain.

That won't happen, because the mass transit will also be on the guideways, and there will be plenty of room on the guideways for all of the private cars, the transit, taxis, light trucks, and fast freight. I have been writing that the each lane of 60-mph guideway of the type that I advocate would be the equivalent of twelve lanes of highway, and each lane of 200-mph guideway would equal forty lanes of guideway. The latest highway-capacity data I have from the Minnesota Department of Transportation tells me I need to amend those figures downward a bit. Doing the arithmetic, one lane of 60-mph guideway will carry the traffic of approximately ten highway lanes, and one 200-mph guideway lane will carry as much as thirty-two lanes of highway. The motorcycles, hot-rodders, house and boat trailers, and the big-rig semi trucks will have the highways mostly to them selves. All of the rest of the multi-lane highway traffic will be on one lane of guideway, with room to spare in all but a very few places.


Now responding to David Gow's 7/30/02 Dual Mode Debate: Where's the public transit?

I'll pass on the urge to debate point-by-point with Francis Reynolds, because his position is perfectly defensible as well as being internally logical. See, facts don’t bother me, where I differ is how facts are translated into policy outcomes. Perhaps we can chalk up this ongoing debate to the likelihood that Dual Mode and Personal Rapid Transit are apples & oranges strategies for dealing with congestion. Both visions work, the answer to the question of which is best is a matter of personal preference.

Facts may not bother you David; the problem is that you were unaware of some important facts concerning the type of dualmode system that I and certain others propose. You cannot provide a useful critique of something until you understand that something. The information is all in Jerry's Dualmode Debates and Dualmode sections; but you apparently haven't had time to do enough homework. The best place to look for details on my proposal is in /itrans/hilo2.htm

The "apples and oranges" saying doesn't fit, because the choice is not "either Dualmode or PRT" since PRT can be an optional subset of dualmode. We will probably have dualmode rental cars (21st-century PRT) on our dualmode guideways, but straight PRT guideways would not carry any of the other kinds of essential traffic that dualmode will. And no, it will not be a matter of personal preference; we are not debating what color to paint the living room. Dualmode and PRT are worlds apart in capability and usefulness. About all they have in common is that they both use something called a guideway, and they can both carry passengers in privacy. Dualmode is bound to win on its merits once it is understood by a broad section of the population. It is confusing and regrettable that PRT and dualmode are now often thrown into the same barrel. "One rotten apple , , , , , , ,"

However, Mr. Reynolds's vision of a dual mode world misses an important component-- what happened to the public transit? There doesn't seem to be much room for it in the Dual Mode equation. For Mr. Reynolds, the standard of service must be door-to-door, rather than convenient walking-distance-- yet the guideway system must be skeletal, with stations miles apart. This means the user MUST drive to and from the system. Shut out of Dual Mode are senior citizens, children traveling alone, and others who don't drive, can't drive, or on occasion choose not to drive.

Public transit was not missed in my dualmode planning. Dualmode can and will carry all of the transit there is a market for, and it is recognized that transit is a vital service for the significant elements of the population you mention. There will be plenty of room on the guideways for transit of all kinds. Yes, door to door is much preferable to walking. Walking is fine for recreation, but walking should be optional not required in all kinds of weather in order to get to the doctor's office. My wife and I are 82. We would gladly trade our present car for a dualmode car, but we would not leave our car at home and walk to a PRT station.

The main point you are missing is that in the coming dualmode transportation era most of the transit will also be dualmode. In street-mode these dualmode transit vehicles can take people as near to their homes as they now do, or closer if the riders and/or the rest of us wish to pay more for better transit service. But there could still be single-mode transit on the streets and highways, and single-mode transit on the dualmode guideways, if there would be a remaining market for single-mode transportation. These factors and the degree of transit subsidization if any, are social and economic problems that will not be adversely impacted by the acquisition of dualmode transportation. On the contrary, the availability of dualmode guideways in addition to the systems we now have will make many more transit options available.

David next objected to certain aspects of the RUF system. I will leave their defense to Palle Jensen, but it should be noted that RUF and my "HiLoMag" dualmode systems differ in major ways. This rebuttal applies to my own concepts. Comparing RUF and HiLoMag would be "apples and oranges." There would be no timetables and no transfers used in the dualmode system I propose, anymore than there are schedules and transfers required to use our streets and highways.

Dual Mode supporters recoil from the number of stations required by PRT, saying that the same general level of service can be provided by a less elaborate network and fewer stations further apart. But this requires someone driving at each end of the journey, whether that be the individual or a bus driver. Would PRT be more expensive? Well of course it would. But increased coverage means more users, more revenue, and therefore affordability.

Dualmode PRT (rental cars) will have infinitely greater coverage than PRT cars constrained to guideways, and will therefore provide more PRT revenue than single-mode PRT, but you are ignoreing the largest factor of all. As I recall somebody's numbers, about two percent of passenger travel is now in some form of transit, while ninety-eight percent is by private vehicles. With most of the private cars using the guideways the income will be enormous and will rapidly pay for the system and its maintenance. Drivers will pay for guideway use rather than gasoline. And do not forget that freight and other commercial traffic will also provide guideway income. PRT advocates hope that a high percentage of automobile drivers would switch to PRT. I don't think so, especially if they can have a dualmode system instead. The percentage of dualmode PRT rental cars on the guideways will be low, just as it is for existing single-mode rental cars.

In closing, may I note a possible win-win resolution to this debate: ULTra. It's being introduced as public transit PRT, but I think we all know that Martin Lowson's intention is to eventually open future ULTra networks to Dual Mode cars. Note that by the time that happens ULTra networks will already exist, designed-for-PRT, with all that implies: each system an assemblage of guideway loops, serving many stations spaced at about a half-mile. From a developmental standpoint, ULTra is in the lead. The precedent it is setting-- PRT first, Dual Mode later-- may be an example of which all of us, PRT supporter and Dual Mode supporter alike, should take note.

ULTra is a light pneumatic-tired PRT system that could never be converted to the far higher speed, traffic capacity, and weight limits necessary for the standardized urban, suburban, national and continental multiuse dualmode system that I consider essential. Most of the guideway rights-of-way could be salvaged, and that is about all. In my mind none of the other PRT and dualmode systems currently under development could be effectively expanded to an optimum standardized national system either. These current small companies are searching for niche markets, struggling financially, and have limited engineering staffs. Therefore understandably they are not able to think big and take the all-encompassing position that I am taking. I have no company, no payroll or schedules to meet, and no investors to keep satisfied; so I have nothing to lose but my sanity.

I wish I could tell you how the big-picture dualmode revolution is going to get underway. I have learned that it will be extremely difficult, and that it will take a long time, but I refuse to believe that it would be impossible. "The impossible takes a little longer." It has to be possible to "sell" the dualmode revolution concept, because there are no other adequate solutions. As many other people have noted, the problems will be largely political and sociological, not technical. But we in technical fields must make the best and most far-sighted decisions possible. Unfortunately I won't be around when the big decisions are made. All I can do is to urge the rest of you to think big, think future, and do it right.

Don't cut pennies. Would the Brooklyn Bridge still be there if the penny-pinchers had succeeded in reducing the diameter of the suspension cables? Would the Grand Coulee and Hoover Dams still be harnessing the Columbia and the Colorado if we had made them thinner to save money? One of our astronauts observed to his "cellmates" while in space, "Doesn't it give you a warm feeling to know that everything around us was designed and built by the lowest bidders?"

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Last modified: August 31, 2002