Kirston Henderson's Dual Mode System
Design "Absolutes" - 26 formulated originally in
May, 2000, 10 more in June, 2008


1. High safety levels for both users and others. All systems must be highly tolerant to most types of failures and be able to continue to operate until vehicles can be removed from the system or the system can be shut down in an orderly and safe manner. Extreme levels of safety are essential to acceptance.

2. Affordable cost to system owners and users. The system must provide the desired services at costs comparable to or below the costs of providing these services by conventional means. The system must not require significant added investment on the part of users. The cost of dualmode cars must not significantly exceed the cost of current conventional cars.

3. Pay its way without public tax support. The system must be able to operate at a profit. It must also earn sufficient revenue to recover the initial investment with a profit on a timely basis. It must not depend upon public tax funds for construction, operation or maintenance. (One major aerospace company fell into the trap of designing an automated people mover system on the assumption that it did not have to profitable,but only be lower in cost than current, money losing light rail systems. After spending millions of dollars, they were forced to abandon the project.) This is a real economics lesson!

4. Improved transportation service for all users. The system must offer significant improvements in transportation for all system uses and users. Clearly evident improvements in speed, comfort, safety, and convenience are essential for any widespread success.

5. Low environmental impact. The system must present a minimum adverse impact to air quality, noise, population disruption and land disruption. The system also must not involve any massive, light-blocking overhead structures. (In general, the public will not accept any large overhead transit system structures such as those typical previous and most currently proposed elevated rail, automated people mover, and dualmode systems.) The system approach should also avoid any requirements for U.S. Federal Government environmental impact statements, etc. The environmental impact statement process can be a major hurdle for project success in the United States!

6. Avoid or minimize use of diminishing oil reserves. The system must be capable of operation with little or no use of oil. Use of alternative energy sources is essential for any long-term success of advanced systems.

7. Provide personal automobile-equivalent service. The system must not force the general population to shift from personal automobile service to shared public, mass transit service.

8. Provide improved public mass transit service. The system must provide significantly improved public mass transit service so that it will attract more users than current systems.

9. Provide automated cargo shipment. The system must provide a fully automated means to ship cargo without need for trucks or truck drivers. Currently, large trucks are major contributors to air pollution, traffic, and conventional road deterioration. An influential transportation official recently advised the Texas Legislature to eliminate large trucks from the highways.

10. Provide fully automated, 24-hours a day service. The system must offer service at all times of the day and must not depend upon human system or vehicle operators.

11. Provide safe and full service under all weather conditions. The system must be able to operate normally under all conditions of adverse weather (except the most severe hurricanes). A system that shuts down or becomes less safe in  the presence of adverse weather is not acceptable and should not be tolerated.

12. Offer high degree of earthquake resistance. The system must be capable of being constructed so as to withstand earthquakes with minimal damage and without endangering either users or others.

13. Use readily available and affordable material. The system must be capable of being implemented without use of exotic or expensive material.

14. Avoid use of exotic, unproven technologies. The system must be implemented without development of any exotic, unproven technologies. Dependence upon significant new technology developments will doom any attempt to put an new system into place within a reasonable time span or cost.

15. Compatible with existing transportation systems. The system must be fully compatible with existent transportation systems and modes. The system cannot require major departures from public transportation methods and systems. It can not disrupt or require replacement of existing systems. Any dualmode vehicles must fit easily into present streets and roads without special provisions or assignment of traffic lanes.

16. Suitable for wide range of applications. The system must be suitable for the widest possible range of transportation applications in exactly the same form and with the same equipment. Failure to meet this requirement will doom any system to limited application and create a need for a variety of different and incompatible systems.

17. Operate with grades similar to road grades. The system must be able to be installed to operate with grades similar to those of normal roads and must not require massive earth moving projects for implementation.

18. Allow use of both system owned and user owned vehicles. The system must define a standard set of interfaces that enable use of both system owned and user owned vehicles manufactured by different vendors.

19. Capable of widespread implementation. The system must be capable of being implemented in almost any location and under the cognizance of any local, regional, or national government. Governments must not be required to develop or invoke system standards.

20. Capable of rapid installation with minimum disruption. System components must be capable of rapid installation without long or major disruptions of on-going activity or traffic. Existing traffic and activities cannot be shut down or seriously impeded to allow building of a new system.

21. Use existing road and street rights of way. The system must be capable of being installed using existent road and street rights of way with a minimum of added right of way. Any requirement to acquire large amounts of added right of way will doom any system to slow or no implementation.

22. Installed system segments immediately usable. The system design must enable system segments to be usable immediately upon installation, rather than waiting for an entire system to be put into place.

23. Avoid creation of traffic problems on conventional streets. The system must be capable of providing transitions to existent traffic and streets by distributing the exiting traffic so as not to create bottlenecks at terminal points.

24. Enable traffic buffering re-routing for problems. The system must include provisions to buffer traffic between different system lines and re-route vehicles in the event of system problems or failures.

25. Allow non-stop travel. The system must offer non-stop travel between user trip origination points and destinations and must not require change of transit modes or significant slowing of travel except in cases of shared, public
transit vehicles.

26. Fully elevated rail system. The system must be entirely elevated to assure safety from and to persons, animals, and objects on the ground surface. Elevation is also essential to enable operation in areas of heavy snowfall.

Additions, by Kirston Henderson, in June, 2008

1.  Easy and rapid emergency escape from any stalled or burning vehicle without external assistance for all passengers to an safe emergency walkway and ultimately to the ground.

2.  100% effective emergency vehicle steering even in the case of loss of complete electrical power.

3.  Fault tolerant and self-healing control systems that allow any failure to be detected and overcome to the point that the vehicle can reach a siding where it can exit the main guideway.  Such failures should be reported to central control centers where appropriate action can be taken by human monitors.

4.  Provisions to prevent any vehicle from being blown by wind from the guideway or derailing.

5.  Capability of all vehicles to operate in reverse when necessary to clear guideways in the event of some catastrophic failure of a vehicle or a section of the guideway.

6.  Guideway life of, at least, 100 years without need for maintenance that would require the guideway to be shut down for more than a very few hours. That includes that there be no need for painting or significant repairs of any sort.  Wear items should be on the vehicle rather than the guideways.

7.  Essentially silent operation to persons on the ground.

8.  Resistance of guideways to being broken or collapsing during anything other than the most severe earthquakes.

9. Provision for standby emergency power generators to enable vehicles to be moved to stations at, at least, reduced speed and one at a time if necessary,

10. Battery operated guideway controls and communication and communications within vehicles to enable emergency communications at all times between passengers in vehicles and central control center personnel.



Last modified: June 15, 2008