Sunday, December 20, 2009
In the last post I touched on the idea that vehicles such as ULTra could be driven by “joystick”. This idea of driving by electronic controls (as opposed to the current practice of having actual mechanical connections between the pedals, steering wheel and the engine and brakes,) is not new. The use of electrical motors and regenerative brakes starts us down that road, which leads to the “skateboard concept.” (scroll down to post 50 for a picture)
Let’s take this line of thinking a step further. If the Ultra vehicles are guided by some kind of laser system that centers them on the track (with accuracy of less than a centimeter, I understand) such a system could presumably be fitted on private, steerable cars as well. An example of a steerable car which could presumably be easily modified for the ULTra control system is this Michelin concept car. The idea is that you drive your car to a ramp (or car “elevator”) and driver control is switched off and automatic control is switched on. Voila! You are now in a fully automatic PRT system until you are dropped off.
That Michelin video raises an important point however. People are really in love with their cars. The very best selling point of this electric car seems to be its muscle. Then there is the addition of luxurious creature comforts, such as adjustable seats, high-end music, etc. It seems to me that private vehicles will always become more and more loaded with features and power until something or someone steps in to halt it. Electric vehicles, in themselves, are not without environmental costs. The electricity they use must be generated, and this, itself, generally involves combustion. The prospect of hundreds of millions of Chinese cars being recharged by way of coal (their principle source of energy) power plants is truly frightening. Coal is, of course, 100% carbon, so there is no fuel on earth that is worse for global warming. Anyway, the point is that there would need to be some kind of societal decision as to how much to limit the power and weight (and therefore luxury) of these vehicles. We can’t afford a guideway network for Hummers. Because any vehicle on the system would need to be meticulously maintained, (combined with the necessary luxury limitations noted above) perhaps some type of leasing model would be the way to go.
This scenario does not eliminate “ordinary” PRT operations. Fully automatic “taxis” could still populate the track. PRT vehicles could come down to ground level and use a special lane to get to stops which cannot be served by raised stations. This would, of course, create the same interferences with vehicular and pedestrian traffic that plague other forms of surface transportation.
The main problem with the whole idea is the same problem that plagues all supported PRT systems. All supported systems inherently discourage true point-to-point travel compared to hanging systems. If they come to the ground they interfere with other traffic and pedestrians. Ramps must be fenced off for safety and are ugly. Stations must be positioned so that ramps won’t block driveways. If elevators are used to raise the passengers or lower the vehicle, the station is considerably more expensive. This is a big deal if you consider the economics of the network. I believe that in many cities the ridership figures are such that a great percentage, maybe even most, of the city would go unserved by the PRT network unless simple “bus-stop” type boarding areas are employed. I think this is a point worth repeating. It is a very big problem if the cost of stations precludes their use in large areas of a city. PRT needs the “network effect” to fulfill its promise as a transformational technology. Of course this is just money problem. If the government wanted to switch some road funds into PRT that would be a different matter. From a business perspective though, there will always be a number of riders under which it becomes unprofitable to create local service.
For the time being I remain very wary of any system that can only take the “low hanging fruit” to market.