Response to Comments by Hopkins Regarding a National Dualmode System with Respect to the FlexiTrain Dualmode Concept


Charl du Toit, Inventor, New Zealand

May, 2000


Thanks to Dr. Hopkins for taking the time to comment on a particular Dual-Mode concept, providing a rare perspective, and certainly giving an opportunity to sharpen arguments for a broader audience.


I would like to make use of the opportunity to highlight some of the features of FlexiTrain, which started out as a simple range extender for Electric Vehicles and has developed into a Dual-Mode transportation system. I found Dr. Hopkins’ points particularly interesting because I assume he was unaware of this technology. I have shortened his paragraphs so as to avoid repeating the entire discussion. 

…tight integration between vehicles and guideways, often also including the control system… technical evolution of each element …dependent on parallel and simultaneous modification in each system component. …the dominance of traditional aviation, highway and rail technologies is their adaptability.

FlexiTrain does not require such integration. It relies on ATIS and ITS technologies already being developed in the automotive transportation field.


Just as importantly, it does not preclude its later development into just such a guideway-based automated system. This is one element of future-proofing the system.


Within relatively modest bounds, any road vehicle can operate anywhere in the highway system…More importantly, improvements have been substantially "downward compatible,"

This neatly describes FlexiTrain vehicles. They can run individually, or “informally” platooned, on normal roads. Additionally they have use of the FlexiTrain Superhighway.


A key point is that these systems…evolve, adapt to changing needs, and incorporate technological advances in a basically incremental fashion.


A fundamental tenet of FlexiTrain is future-proofing. A vehicle must comply with certain requirements centred on the PowerBar coupling. Beyond that, development could follow wherever the automotive field goes, be it power source, in-car software or styling fashion.

A related factor is the reality of very long implementation times for physical infrastructure

A modest infrastructure investment in departure nodes is required to start the system off. Operating lanes can be demarcated for peak use and removed as required. Where demand requires, and only then, permanent lanes can be established. These would evolve into fully automatic systems.


The "system" actually comprises the investments and activities of many independent entities: the private sector, a large number of governments at all levels, and the users.

FlexiTrain extends the existing private transport paradigm. By not attempting to upset the stakeholders in the present order, it may stand a chance of acceptance. A strong feature of the system is that it can be as “private” or “public” as the particular installation demands.

It can be argued that the Internet pattern is the best model for how transportation systems are created and evolve.

FlexiTrain goes further: implementation is cheap enough to be driven top-down, or from private sector initiatives. In reality, this will be a dynamic balance struck between the desire of local authorities to improve the urban environment, and individuals to improve their personal transport.

The high speed goal also poses serious limitations on route alignments.

FlexiTrain uses existing design highway speeds and thus fits into existing town planning. It has been shown that high maximum speeds in urban environments are largely negated by the other elements of the trip total.

There's also a chicken-and-egg problem… people would have to be persuaded to buy the special vehicles that would have very limited use in most cases, and might be obsolete by the time they had guideways on which to operate

Unlike systems using major guideway infrastructure from the outset, there is not really a critical "minimum size" for the FlexiTrain system to be demonstrated. Two vehicles can do the job, although three is a practical minimum.

The high capacity … 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.

FlexiTrain has a unique capability among dual-mode systems: its destination can be radically modified while en route. This works extremely well with ITS under present development. The system will choose the “best fit” least-congested destination, based on real time, dynamic traffic modelling. Individual vehicles will be updated with destination data and likely conditions at the drop-off point, together with further routing information as required.

Think about real origins, destinations, stops made, chained trips…to get a feeling for how people actually use the transportation system.  

I found this to be the most important statement of all, given who is talking.

“Systems People” might pause and try to overcome their infatuation with a particular technology, to ask themselves why it is necessary to do what they are attempting. Thanks again to Dr. Hopkins (and Francis Reynolds, for that matter) for opening up an interesting avenue of discussion.

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Last modified: August 13, 2002