Buenas Dias, Mike Jensvold idea for changing taxi regulations is interesting. A friend in town from DC was surprised that grabbin' a taxi downtown yesterday would cost us more than a couple bucks for the mile or so trip. But then again he's used to grabbin' a cab because you can't count on the buses showing up on time or at all.
As for PRT demonstration, I've given this some thought. As I posted @ 4 weeks ago, PRT is essentially the same type of system as the new fancy pants baggage system installed at Denver International (DIA) in the mid 90s. The difference is the safety issue is that much more acute. The systems are essentially the same because they both involve a single car / cart that can start at any point on the system and can have a destination anywhere on the system. It's just that one carries a piece of luggage and the other carries a person. I'm not sold that a demonstration system will prove anything. As simple as the concept of PRT is to explain, the size of it makes it very complex. The baggage system at DIA has been a complete flop. This despite a mini system having been built for United's use at SFO and a larger version of SFO's built at the "new" airport in Munich. The issue for a system like that is that something that is 10 times bigger is NOT ten times more complex. It's likely thousands of times more complex. If I've got the concept right, the complexity can be seen by the number of stops on the system. The number of possible routes that can be taken from stop A to stop B, stop C to Stop A, et al. So the number of possible routes is (n-1) + (n-2) + (n-3) + ... (n-(n-1)) where n is the number of stops on a system. So 7 stops gives 28 possible routes for the computer to handle FOR EACH CAR. Note that since a system is going to be running more than one car. A system with 17 stops gives 153 route possibilities for each car. 40 stops gives 820 routes; 100 stops yields, 5,050 routes; 250 stops gives 31,375 route possibilities. I think you can see how quickly the complexity of the system grows. And as the system adds more stops, one would assume they're adding more cars. I don't know the number of nodes on the system at DIA. That baggage system had to serve 89 gates. Surely there were origination points in the terminal for every couple of ticket counters so I'll assume 25. There are 24 curbside baggage stations. I would assume another 27. That ultra crude estimate would make for 165 nodes. At peak usage, it had 3,550 cars in use on that system. So each of the 3,550 cars has @14,000 route possibilities. In comparison, if the city of Minneapolis were to implement PRT for the city with a stop every 1/3 mile, it would take about 350 stops to serve the entire city. Or to put it another way, it have about twice the number of nodes as DIA (keep in mind my estimates were crude for DIA). But that yields nearly 62,000 route possibility for each car. And how many PRT cars would be running on the system at any one time? It took 3,500 for DIA's system which had half the nodes and would be considerably than half in terms of track milage to cover. Keep in mind another element of complexity, the speed of the cars. DIA's system had a peak speed of 19MPH. Surely a larger system such as MPLS's would require a higher speed than that to compete with cars. You may say that's unfair to assume that the entire city would be covered. They're likely to role it out in smaller portions. But to not cover the entire city would defeat the purpose of PRT. It's advantage over traditional mass transit is that it can deliver people nearly doorstop to doorstop without a transfer. To do this, a PRT system has to quickly cover major parts of the city. It looses effectiveness once it becomes merely another cog in the transportation machine. I hope this helps to give some sort of ball park idea on how truly complex building a PRT system would be. And the thing is, DIA's baggage system is a flop. It failed. United Airlines is on the verge of abandoning it. DIA had to sell it to United because other airlines refused to use it. And the city of Denver to this date, 8 years after the airport opening, still owes $300 million just for the cost of the baggage systems at DIA. And here we are talking about building a system that is going to be longer, have more stops, have higher safety standards (the occasional squished bag is a different issue than having an occasional squished person. It's not an easy task at all. And I do not feel that a demonstration system proves that as a whole it can work and work well. Why should the taxpayers take on such a risk? If telecommuting becomes socially acceptable we could see a huge drop in traffic. And at that other congestion issues could be solved in the next 10 - 20 years if cars can "drive themselves". The latter is just starting with some vehicles already able to avoid crashes while cruise control is set. And the former, telecommuting, nearly has the technology in place to make it cheap and practical. Throw in emission reductions via hybrid vehicles and, further off, fuel cells and it's likely that we're nearly at the peak of the personal transportation problem. When we have a city that still needs to pay down it's existing debts that consume something like 12% of the annual budget, why take on this huge risk? Allen Graetz Lowry Hill -----Original Message----- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Barbara Lickness Sent: Wednesday, January 05, 2005 8:48 AM To: David Shove Cc: [email protected] Subject: Re: [Mpls] To PRT or not PRT The "demonstration" system you speak of has been proposed. The cost a year ago was proposed at $24 million for a 6 block stretch if I remember correctly. That's a lot of money for an unknown quantity. If the city or state would be foolish enough to endorse such an idea of a demonstration project I say do it around the chain of lakes. It would connect everyone with all the lakes and there could be an opportunity for the park board to place an ice cream stand at every station. You could put hooks on the outside to hang the bicycles on. Tracks could run down Minnehaha Creek and people could connect with bus lines all along the way. Why, I think the people living around the lakes would just love seeing a giant iron snake winding it's way past bedroom windows in the name of new technology. Or, how about Roseville? Barb Lickness Whittier ===== "Never doubt that a small group of thoughtful, committed citizens can change the world. Indeed, it's the only thing that ever has." -- Margaret Mead REMINDERS: 1. Think a member has violated the rules? Email the list manager at [EMAIL PROTECTED] before continuing it on the list. 2. Don't feed the troll! Ignore obvious flame-bait. For state and national discussions see: http://e-democracy.org/discuss.html For external forums, see: http://e-democracy.org/mninteract ________________________________ Minneapolis Issues Forum - A City-focused Civic Discussion - Mn E-Democracy Post messages to: mailto:[email protected] Subscribe, Un-subscribe, etc. at: http://e-democracy.org/mpls REMINDERS: 1. Think a member has violated the rules? Email the list manager at [EMAIL PROTECTED] before continuing it on the list. 2. Don't feed the troll! Ignore obvious flame-bait. For state and national discussions see: http://e-democracy.org/discuss.html For external forums, see: http://e-democracy.org/mninteract ________________________________ Minneapolis Issues Forum - A City-focused Civic Discussion - Mn E-Democracy Post messages to: mailto:[email protected] Subscribe, Un-subscribe, etc. at: http://e-democracy.org/mpls
