Saturday, August 15, 2009
Here’s something to think about. In this picture, the vertical blue lines represent payload capacity, something like 50 to 75 kg per line. I originally started drawing this picture to explore weight distribution of possible track compliant vehicles, but then I realized that I had better share a bit of thinking first.
The baskets (A) represent something that could be used in manufacturing or for baggage handling. It’s not PRT, but it is a possible avenue to a proving ground and test track. A successful system would be a great confidence builder for the hardware, software, and the company that installed it. Having a demonstration project (that you get paid for) seems like something worth considering. (Currently the “state-of-the-art” technology involves conveyor belts or other floor space intensive systems, with laughable forking and destination sorting technologies.)
Cargo containers (B) can be similarly used, including outdoors or across town, if necessary. Cargo can be loaded and scheduled to depart automatically, so it can travel in the middle of the night, eliminating the cost of drivers working nights or being stuck in traffic in the day and, naturally, saving gas and payroll. Cargo containers could also be programmed to take the “long way” to their destinations to reduce network congestion, (for a reduced rate, of course). These would be great for moving mail between substations, for example.
The small “pods” (C) represent what would be best for 95% of rides taken, being designed for two or less passengers. These small vehicles could be pretty fast, passenger profile permitting, and would therefore be competitive with cars for longer commutes time-wise. Although current models generally assume identical velocity, these models also assume very limited networks. It should be noted that no system will be full of vehicles 24 hours a day, and that in a more comprehensive network, routes can be dedicated to faster or slower traffic dynamically.
The full size “pods” (D) can be used for families, people with bikes, baby carriages, the disabled, people with luggage, etc. These would have the “standard,” more gentle and slower ride, and employ greater headway between vehicles. Because there are societal benefits to traveling with a bike, or traveling in groups, or enabling the disabled, etc., I think that this class of vehicle should be subsidized and be more numerous within the network than ridership statistics alone might dictate.
The last, labeled (E) is a GRT or “Group Rapid Transit” vehicle and is designed for downtown or shuttle environments. It cannot ascend or descend steep slopes, and is designed for more expensive, high capacity stations. It designed to run profitably in simple loop or “back and forth” configurations such as between airport terminals, and, most importantly, could get the first PRT compliant track built. GRT can skip stations without passengers, like a city bus, but it can also have the intelligence to coordinate with other such vehicles to match passengers and destinations. This, and their small size, compared to buses or trains, means that no passengers have to sit through more than a couple of quick stops. After more loops are completed PRT vehicles can be added as needed, and the GRT vehicles retired or converted to night delivery use. (Or perhaps they will be found to have continuing utility within the system. I am not aware of any studies involving GRT and PRT sharing track, and really have no opinion, at this time, one way or the other.)
Most people are linear thinkers. The linear thinkers among us will see all of these vehicles as a hopeless distraction. I, on the other hand, usually look forward and imagine an optimal embodiment and environment, and then backtrack from there. This enables a viewing of possible pathways to a desirable outcome that cannot be had otherwise. It’s like cheating at solving a maze by starting at the end, so if I seem to fluctuate, sometimes, between reality and sci-fi, that is the madness behind the method…I mean, “the method behind the madness.”