The problems and concerns voiced by these two gentlemen are certainly serious and real enough and many good points and observations are made. However, I fail to understand how these observations support palletized dualmode as the only possible solution to our growing transportation problems, and I will certainly contest Turnbull's final point: It is not an established certainty that a dualmode system must initially be entirely pallet operating.

Originally I was preparing a rebuttal of the postulated pallet inevitability in future dualmode systems, but Francis Reynolds beat me to it with his "Dualmode and the facts of life" and I quickly abandoned any hope of improving upon his words. I can only say that I agree with almost every word written, especially on the evils of (large) interim systems as well as on the need to standardize from the outset.

The champions of palletized dualmode, in my humble view, all make the same mistake: They consider the dualmode idea mainly from a system operator’s viewpoint. R. Guadagno envisions a system optimized for lowest possible energy consumption. R. Arthur thinks guideway space could be more productively used by multiple-passenger vehicles and W. G. Turnbull believes the system should be in total control, thus should own all the operational pieces. Van Metre Lund is simply concerned that his Autran system must be revenue earning. And everyone seems to agree that transportation careerists and other bureaucrats should be allowed to decide what kind of system we will build, if any at all. Has anyone ever considered asking the potential users?

I’m not an engineer, politician, transportation careerist or possible dualmode financier. I’m merely a potential user. And this potential user will not share a vehicle with other travellers (family and friends excepted), nor will he wait in uncertainty for a pallet or other device to arrive before he can continue his trip. He will favour a system that is equally advantageous for short as well as long trips and it must be immediately available when needed. As a citizen I will oppose living next to structures (guideways) that are unnecessarily large, and I dislike the idea of bulldozing countless expensive buildings to make room for pallet-depots and/or excessively large access facilities. The price per mile for use of the system is very visible to users, so it’s an issue as well. As low as possible, thank you!

One of R. Arthur’s statements reads "the key is providing a product for which there are hundreds of millions of potential costumers." Funny that he should mention it, because this requirement is a true dualmode system's best selling point. People will not walk, will not wait and will not plan their trip in advance. They simply want to go directly from their origin to their destination, whenever they are ready and they want privacy while underway. These stringent requirements eliminate most existing as well as proposed transit systems from our positive list, leaving only two systems. Our existing road-/highway-network and any future dualmode system utilizing true dualmode cars.

Palletized dualmode will involve waiting and uncertainty for its users and could not generate "hundreds of millions of costumers." Some of the reasons why it couldn’t have already been mentioned in my earlier paper, titled "A few thoughts on palletized dualmode." It is not enough to simply state that, "the problems with palletized car ferries are not insurmountable." Well, I’m sorry but they seem to be and will likely remain so.

Considering that Francis Reynolds has already so well argued the case of true dualmode and the need for standardization, I will instead devote most of this letter to the presentation of an alternative implementation strategy for a true dualmode transportation system. A strategy that undoubtedly will cause controversy but all ideas should be considered, bearing in mind the serious transportation crisis that we face.

My proposed implementation strategy is founded on four premises, each of which will be considered in turn. The four premises are –

a) Choose technologies enabling car-manufacturers to build true-dualmode cars using already developed production practises. Also retain conventional propulsive technology, so that dualmode cars will not suffer reduced performance (speed/range) when using conventional roads.

b) Offer dualmode cars at prices equal to or (preferably) lower than conventional cars, through discriminate taxation. Taxes will be levied on conventional cars or dualmode cars will receive a tax-reduction.

c) Integrate public transit services from day one, so that guideways will be used by public vehicles, thereby easing the financing problems during the start-up phase

d) Forget about the US, at least initially. Europe will provide much more fertile soil for the dualmode transportation concept.

Commenting first on the last premise: I have in the course of this discussion on several occasions come across the idea that we need a dualmode czar to knock down bureaucratic opposition and advance the cause of dualmode. There seem to be general agreement that without a czar any proposed system would die in its infancy. The US President has been suggested as dualmode czar, but unfortunately his ears are inaccessible to us dualmode champions and they are likely to remain so. Even if he could be approached the president would be very unlikely to support a dualmode project in the present situation as it pose to many risks providing little (political) benefit in return.

In his last comments Francis Reynolds likened the dualmode project with a war-effort and it’s an useful comparison insofar that the political system in the US, with all its inertia, reacts much faster to threats than to visionary proposals. The atomic bomb was a reaction to a military threat and a fear that someone else (Germany) should manage to get it first, while the Apollo-program was a reaction to an apparent technological superiority of the Soviet Union in the days of Sputnik and Gagarin. The national pride was under attack.

So if we want to promote the dualmode idea in the US, we should create a threat to the American economy, way-of-life or national pride, where the obvious solution would be a dualmode transportation system. This threat/fear dynamics in all likelihood provides the best opportunity to advance the dualmode idea in the US. In fact, I’m convinced that the mere knowledge that several European nations were seriously contemplating building a dualmode system would be enough to secure dualmode some high-level supporters (including the President) in the US.

We all agree that a dualmode transportation system will have important societal and environmental benefits as well as provide an efficient transportation infrastructure offering economic advantages to businesses. So it is no exaggeration to say that it would be totally unacceptable for any major developed nation to do without a dualmode system if everyone else had it.

In Europe we have an entirely different political climate, where decision-makers are more accessible and more open to new ideas, especially in the smaller nations. The Scandinavian countries come to mind as do the Netherlands, where politicians are often willing to try something untested. Also the independently minded German "Bundesländer" are always fearful of being overtaken by events and would therefore also be fertile soil for a proper designed dualmode proposal.

The societal and environmental aspects of our transport infrastructure are given more consideration in Europe than is the case in the US. Much is done to reduce the number of accidents and harsh restrictions are in place to protect the environment. Taxes are levied on individual transportation (cars/fuel) to "persuade" people to drive less, buy smaller less polluting cars or to abstain from cars altogether. In this political climate would it be much less of an uphill struggle to convince people and their decision-makers that dualmode is the appropriate cure to our numerous transportation problems.

The mentioning of taxation practises in Europe leads me directly to another of the premises in my proposed implementation strategy. And I’m happy that I can include a fresh case from Denmark as an illustrative example of how dualmode cars could be made car-buyers favoured choice.

Last year the Volkswagen Company introduced their little Lupo model with an engine capable of running 100 kilometres on less than 3 litres of diesel. Unfortunately the technology enabling such low consumption is expensive, and as a consequence the eco-Lupo is very expensive compared to other cars of similar size. Here I should mention that we have very high taxes levied on cars in Denmark: "Get one – pay for three" is a common saying here. But in an amazingly short time the political will to reward the technological advances introduced by Volkswagen was secured. The taxes on the eco-Lupo and other very-low-consumption cars were reduced by one-third and there are now so many costumers waiting for their Lupo that Volkswagen will be unable to catch up for at least another year. The car offers superior technology and lower running costs at a purchase price only slightly higher than for other cars; and apparently buyers are eager to embrace new ideas under such conditions.

This example indicates that buyers, given the choice of two equally priced cars of similar performance, size, quality and so on; one being of conventional type the other with dualmode capability; would overwhelmingly opt for the dualmode car. Even if there were only a few miles of guideway available, buyers would try to secure the future value of their expensive new car, by choosing one that was equipped to utilize yet to be built guideways. Of course it would only work if buyers could be convinced that decision-makers were firmly committed to dualmode and the guideways therefore would be built. This conviction is provided through the discriminate taxation scheme, favouring dualmode cars.

Most, if not all, European nations are already demonstrating their willingness to favour certain types of cars (or fuels) and discourage others through the selective use of taxes, and it would certainly be a viable way to advance the market’s acceptance of dualmode cars even before most of the guideways were built. The many new owners of dualmode cars would soon exert an immense pressure on decision-makers to get more guideways so they can utilize the dualmode capability of their cars. So this will be a self-sustaining process, once put into motion.

The recipe is straightforward. Build a few stretches guideway, then sell a lot of dualmode cars (buyers will enthusiastically accept dualmode capability if it’s included at no extra expense) and soon the demand for more guideways would be so overwhelming that it would be impossible to ignore. Suddenly the infamous egg/chicken dilemma seems quite manageable. The answer is to let dualmode cars precede guideways, except for the initial few miles. I have to add that I believe this scheme would be very difficult, if not outright impossible, to implement in the US, given the sacred status of individual transport there, which means that any proposed tax on private cars would be immediately killed by the political establishment.

The third premise is closely interlinked with the aformentioned taxation scheme. In order to supply the many buyers eagerly embracing the "dualmode capability for free" concept with attractive and reliable dualmode cars, we will have to choose technology that minimizes the extra production cost of adding the dualmode capability. This means that radical alterations like roof-mounted suspensions, extra sets of wheels, all-electric propulsion (for road use) or adoption of MagLev (sorry, Francis) will most likely be ruled out.

The list of necessary changes to add dualmode capability to a conventional car could look something like this –

- Adopt a drive-by-wire system, so that all mechanical forces are applied through a computer. Drive-by-wire systems will be introduced anyway, dualmode or not, and are even expected to make cars cheaper

- Add a guidance system, providing safe guidance while on the guideway. The system should be simple, cheap and reliable. It could rely on front-wheel steering, magnetic forces, mechanical forces (a guide rail) or any combination thereof

- Add electric propulsion (rotary or linear) for guideway use. Again simplicity and reliability are important

- Improve tire-technology, primarily by adding devices enabling tire-conditions to be automatically monitored

- Finally add enough on-board computer-power that all functions can be monitored and controlled automatically

With clever engineering these changes could be introduced, so that our future dualmode cars would have an appearance and before-tax price almost the same as conventional cars. The dualmode cars would be built by existing car manufacturers, roll from already existing assembly lines and would be sold by existing car dealers. And after-tax prices could be lower than for conventional cars.

The last premise is not really my idea, as it has been repeatedly promoted by Palle R. Jensen for his RUF concept. The idea is to offer public transit services, running dualmode mini-busses and the like on the guideways from day one, thus a public transit company would be the very first paying costumer and user of the guideways. This has a number of beneficial effects –

- It will be more attractive for decision-makers to endorse an improved public transit system than a dualmode system simply considered to be a highway replacement.

- The necessary money could in part be diverted from public transit budgets, instead of taking it all from the highway/road budgets.

- There will be many paying users from day one, although only few of them would be using privately-owned vehicles.

- Everyone will be able to experience the "dualmode feel" first hand, simply by buying a bus ticket. This will in all likelihood convince more people to buy dualmode cars

Everything with even the slightest scent of public transit has an irrational and entirely unjustified strong backing from a large crowd of European politicians. It’s insane, but it’s also a fact of life, so why not take advantage of it. At least we could then waste tax-money on dualmode public transit instead of on conventional public transit. And the tax-money wasted on dualmode public transit would help dualmode in general attain the critical mass necessary to make individual dualmode a reality.

With this imaginary implementation strategy for a true dualmode transportation system I hope to have demonstrated, that there can be many possible ways leading to a dualmode transportation system and true dualmode is a strong and fit contender in the race. The world is a place with few certainties. W. G. Turnbull believes pallets are one of them. And R. Arthur believes it behoves us to think incrementally. Well, I believe it behoves us to think ahead. If we think too incrementally, we will only see our feet and their next step; not the trip-wires ahead of us, and we are therefore destined to stumble. Pallets, in my humble view, are trip-wires, not certainties.