LRT and PRT again
I have vacillated between suspicion of and potential support for Personal Rapid Transit. I can only say for sure that PRT acts as another wedge issue that splits the left and right into mixed factions of supporters and detractors (much like the wedge issue of "ethanol as a gasoline substitute").
Based on the lawsuit between Ed Anderson and Taxi 2000 pointed out by Ken at RoadKillBill (see the "Learn why PRT is a joke" link), we will soon enough see how things shakeout in the Minneapolis PRT landscape.
In the meantime, I wish we can have a transit system like Denmark, where anyone can ride freely available bicycles to get from point A to B. This basically demonstrates the simplicity of the LRT option with the convenience of PRT. Oh to be an irresponsible bicycling youth again, with no cares about locks and flats. And cats have nothing to fear from the slow-moving clunkers.
posted by @whut at May 31, 2005
4 Comments:
Thanks for being open-minded and allowing your blog to be a forum for this issue.
I am as eager as anyone to see this PRT debate end. Please urge the media to do a fair and even-handed investigative story on the claims of Taxi 2000, the CPRT and prominent PRT proponents such as Councilman Dean Zimmermann, Sen. Michele Bachmann and Rep. Mark Olson.
The Minneapolis Star Tribune and other newspapers have the resources to find the truth. Up to now, the Star Tribune has published two puff pieces on PRT and a favorable column by Doug Grow... little more than transcribed Taxi 2000 press releases with a few sound-bites from critics. They have yet to go beyond the "he said, she said" style of reporting. They haven't even reported on the Taxi 2000 trial.
In a recent Star Tribune article by Laurie Blake, she reported that Dubai is considering a PRT system, but I can find no information on this on the web. I have found stories about Dubai investing in a $3 billion light rail system.
I think it's highly dubious that Dubai would invest in an unproven system that doesn't even have air conditioners. If the ULTra system did have air conditioning, it would suck the batteries ULTra runs on after a few minutes in the 100-plus degrees summer heat. Not to mention what a desert climate would do to the plastic shell of the Taxi 2000 pods.
Every one of the engineering problems mentioned in the OKI report and the Light Rail "Cyberspace Dream" article could be tested by independent professional engineers. Computer models, for instance could answer the question whether the slim pylons proposed by Taxi 2000 could withstand the pressure and centrifugal force of fully loaded pods lined up nose-to-nose on a curve at maximum speed. The safe headway distance problem could also be investigated using a computer simulation.
They could also talk to transportation professionals at MnDOT, Hennepin County and the City of Minneapolis. I've talked to some of them about PRT and I've yet to find one transportation engineer employed by a state, county, federal or city government who is willing to put his or her reputation on the line by proposing a PRT system for their area.
Reporters could talk to transit advocates such as Transit for Livable Communnities and the Sierra Club Northstar - neither organization approves of PRT and have resolutions opposing PRT.
They could also talk to community people and ask them if they want to have half the trees on their block cut down for a PRT guidway with a clear view into their bedroom windows.
The truth is out there.
Please write a letter to the Star Tribune and ask for an investigative report on PRT today!
Thanks again.
As this thread appears to be nearing an end, allow me to add my gratitude to Mobjectivist for allowing this forum. The more people who can get accurate information about Personal Rapid Transit, the better for those of us who support it.
To all, I urge-- PRT is not a joke! Read the arguments pro and con, and judge the facts for yourselves!
Ken wrote:
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Please urge the media to do a fair and even-handed investigative story
I couldn't agree more!
I think it's highly dubious that Dubai would invest in an unproven system that doesn't even have air conditioners.
From Skyloop.org documents describing Taxi 2000 (Skyweb):
"Compressor with motor for Air Conditioner (Delphi Auto)... 10.9 [lbs.]
...
HVAC
Ventilation system... 1... 9 [lbs.]
Electric heater... 1... 3 [lbs.]
Air conditioner... 1... 25.6 [lbs.]"
Source
Every one of the engineering problems mentioned in the OKI report and the Light Rail "Cyberspace Dream" article could be tested by independent professional engineers. Computer models, for instance could answer the question whether the slim pylons proposed by Taxi 2000 could withstand the pressure and centrifugal force of fully loaded pods lined up nose-to-nose on a curve at maximum speed. The safe headway distance problem could also be investigated using a computer simulation.
I thought Parsons Brinckerhoff, the firm that did the OKI report, were professional engineers. Too bad what PB evaluated was an imaginary, poorly designed PRT system that PB created on its own, instead of the technology OKI's Skyloop Committee actually chose, Taxi 2000. See this pdf, it's an eye-opener.
They could also talk to community people and ask them if they want to have half the trees on their block cut down for a PRT guidway with a clear view into their bedroom windows.
The scale of Light Rail's right of way and stations means MORE likelihood of cutting down trees. PRT's small dimensions and short turning radii mean it can go around obstacles such as huge, isolated trees--and homes and businesses, that under LRT would be cleared through condemnation.
Attractive, retro-styled PRT guideway supports (the basic pylon covered with decorative shells) can be created to blend into surroundings. Guideways can be run down middle of streets, between rows of trees and away from windows. If the trees are still there, and PRT is going at 25-40 mph, what is anyone going to see in anyone's windows? Besides curtains.
I am unsure whish system is better, LRT or PRT, but i can say that i think they could work together as part of an intregrated transport system, for instance with a feeder PRT taking people to commuter rail stations. It really isnt suited for the large amount of people that need to use the system at the same time like commuter trains can in rush hour. RE air conditioning on the ULTra, i did do some work experience with them as i live near, and actually a business man from the middle east was discussing AC. apperntly theyve designed it into the new model, and there will be enough battery to power it, as it picks up power t each station stopping point. dubious though whether the charge times will be long enough.
Much of the criticisms against PRT is uncalled for, the high expense of the Morgantown track was because with the 20 month deadline, the track was built before the vehicles were designed hence the track was built to support standard LRT vehicles but with tighter turn radiuses. These turn radiuses also required the vehicles to be redesigned to four wheel steering instead of the original two wheel. The expensive track of the Raytheon 2000 system was because the government appoint a pro LRT consultant to watchdog the project and they insisted that only proven propulsion components be used hence the wheels carriage, motors and rails were simply the smallest LRT versions that they could find, note the smallest LRT wheel they could find was 30 inches in diameter. Other criticisms such as a suggestion that two seconds headways would be unreasonable with a 16 second time to full stop is completely ridiculous. Automobiles currently operate with two second legislated minimum headways and have far inferior stoping ability to what has been proposed.
I like LRT, I grew up with LRT but the criticisms against PRT levied by pro LRT activists have really tilted me against those advocacy groups. There's no reason why the two technologies can't co-exist, they address different issues.
As to the technology being unproven. Conceptually, it's point to point on demand hence primitive versions do exist such as automobiles, dial-a-bus, free bicycles, and walking; PRT is simply about meeting the demand for traffic as closely as possible and as efficiently as possible. There are also communication analogs, LRT would be the jumbo packets of the ethernet protocol whereas PRT would be the small cells of the ATM protocol. There are advantages to both and they each have found their niche markets.
I do see problems with PRT. Unlike automobiles, there's no way to artificially increase demand above that required for maintenance and to meet population growth. With automobiles, there's designed obsolescence and individual ego as the vehicles are purchased by the individual consumer hence tail fins, model year vintage, and new fashionable technologies like Hybrid, FlexFuel, Electric and Hydrogen, all of which encourages the replacement of a vehicle before necessary from a practical viewpoint. PRT would be publicly owned hence does not present the same business growth model that automobiles do.
The financing is an issue as well. All the capital costs involved with PRT is associated directly with the project whereas with automobiles, the vehicles are individually financed and the expensive freeways are reactively created to address the problems arising from the popularity of automobiles. This allows for freeway costs that are orders of magnitude greater than either LRT or PRT.
Then there's the question of liability. With automobiles, the individual consumers indemnify both state and corporations by purchasing an insurance policy as mandated by law. With both LRT and PRT, the liabilities remain with the organization and with the manufacturer.
PRT is a good idea, it shouldn't be seen as a detractor from LRT but it is doubtful as to whether it can usurp the automobile.
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