Wednesday, December 24, 2008
First of all, I wish to thank alert readers timote and Dave Smith (TO?) for their valuable contributions. (Also Transportation Enthusiast, who I have since witnessed eloquently correcting a (less-than-enlightened) anti-PRT blog.
The question of collisions at the loading zone/station is a very real one. I had originally imagined “pods” as being very small, probably just 2 seaters, as the idea of building miles of track gauged for third and forth passengers, which statistically don’t exist seemed wasteful in terms of steel, and would make the track and supports thicker and therefore more visually intrusive. There is also the matter of safety, as heavy objects obviously carry more inertia, particularly at cruising speed. At the time, however, I hadn’t given much thought to light freight usages nor traffic density control. My current thinking is that the possibility of freight delivery could be lucrative. As I have written in a soon to be published post, delivery in gridlock is an expensive fact of life for many companies. These entities might have some influence towards PRT adoption. For them bigger is better. Also claustrophobia is an issue with some people, and a little extra space and larger windows would help. Personally, a port-holed coffin sized pod is fine for me, but I’m not your average person. Anyway, as for collisions at stations, I had always thought of a total load (pod, motor, and payload) of less than 750 lbs, traveling at walking speed. This is probably one half of the actual weight I’m comptemplating now, although I am still for excluding four “large” adults. So the question is, “how slow would a (beeping) object of, say 1500 lbs. have to move to not require an expensive station infrastructure?”
My guess mix is 10 ft. per 20 seconds, with striped pavement, possibly cordoned off with chains, a low to medium volume beep-alert, and tilt/bumper sensors on the pod, so that it will cut power if it hits an obstruction that can’t be pushed with just a few pounds.
Part of the reason that open-source PRT is superior to waiting for a company to sell us the solution is that the safety decisions don’t require the overkill that we would want from a corporation whose decisions are primarily profit-based. Certain risks are assumed to exist. Sidewalks are more dangerous because they’re close to streets. So what? I have yet to see the lawsuit requiring cities to move them or demanding damages. Trains and subways and buses and, yes, PRT can’t stop on a dime. But safety parameters designed by a non-profit open-standards organization are not particularly tasty bait for litigation, and PRT could get very slow as it descends.
Finally, Happy holidays! Here is a depiction of me Photoshopped into a Santa Claus photo that went on to consider the ramifications of global warming on the Santa’s base of operations. Imagine Santa’s waterfront property. And the cats? Hey, Everyone loves cute kittens…