Domain: cprt.org
Stories and comments across the archive that link to cprt.org.
Comments · 19
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Mass Transit Is Its Own EnemyI don't buy it. Mass transit sucks everywhere when compared to a well-functioning (or even rather disfunctional) system with cars. (I'm not at all pro-car, I'm just being realistic)
New York transit isn't great. It's comprehensive, and that's important. It makes it a useful system in a way that very few US transit systems are. But mere utility isn't the same as being good; we set our sites very low. But because we've gotten used to that, people think New York has great transit, because even having a choice not to have a car seems incredible.
No mass transit system is as fast as a car -- total door-to-door travel time -- unless the traffic is attrocious. Well, commuter rail might be an exception, because it's one of the most efficient forms of mass transit, but it's only so efficient because it's not at all comprehensive -- both the times it runs, and its destinations. Even faster, more modern trains are only nominally faster than cars, and the better and faster the system, the smaller the number of its destinations, causing a fractured travel experience of ever slower modes. And the fractured experience isn't just slow, it is distracting and alienating. You can bring 10 kids on one train or a bus, but you can't transfer (unless you don't mind losing a kid or two). You can carry your groceries home if you can do it on one bus, but that's about it. And that's not even taking into account the cost, which can often be quite extravagant -- it costs $10 in Chicago for a family of four to take the train or bus round trip.
Traditional mass transit is a nice option, but it only really succedes when cars fail; because they are too expensive, or traffic is too horrible, parking is not available, or you just are unable to drive. Any system that feeds off the disfunction of another -- that cannot stand on its own feet and compete favorably to a functioning competitor -- is a sad system. And that's what we have with traditional mass transit.
With that in mind, I'm not sure that Monorail is a good system. But I know LRT isn't, and Subways aren't, and buses aren't. I don't know that Monorail is significantly different from those, but at least it's an attempt instead of choosing a system proven to be a failure. (OK, they are choosing one of those too...)
Personally I have hope for PRT, which is less proven still, but at least attempts to solve the real problems that public transit faces, with a model that is closer to something that works (cars) while still having many of the benefits we look for in public transit.
Now, if Seattle were to follow the lead of these guys, they might be able to leapfrog cities like New York, without asking for an unrealistic change of geography or demographics.
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PRTI think PRT (Personal Rapid Transit: see also this Salon article) could be an excellent way to move kids about, and there's a lot of possible efficiencies when you build a public transit system that is appropriate for children. Because PRT could take children directly to their schools, it's every bit as good as a school bus, but with less time in transit, thus less fuel, no driver cost, more predictable schedules for parents, more flexibility of destination (useful when a child has more than one home)...
Of course it's still in development, and has had a hard time finding support. But then, the post asked how tech can help...
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other information pointers
Citizens For Personal Rapid Transit
Personal Rapid Transit (PRT)
Austin Citizens for Personal Rapid Transit (ACPRT)
Just to get you started....
(Slashdot wouldn't accept this one...)
Personal Rapid Transit Index Pag
http://faculty.washington.edu/~jbs/itrans/PRT / -
CPRT
Citizens for PRT is another site that may be of interest.
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CPRT.org
If anyone is interested in helping promote this system, check out
Citizens for Personal Rapid Transit.
They're based in Minneapolis, MN, but they do have links to other groups trying to get the system started in their areas.
Brian -
PRTPRT (Personal Rapid Transit) offers many of the advantages of a car (direct, no-stop transport that isn't shared), but automated. It's basically a very small (up to 3 person) train on a small elevated track.
I can understand why people balk at public transportation -- there are a lot of problems with it. It's slow and it just doesn't scale; in "good" public transit places, it's only good because traffic and parking has crippled car use.
PRT can scale better than typical public transit, when you consider both the density of service, and total trip time. Hopefully a more technical-minded crowd can get over the naive idea that big trains can necessarily carry more people. If you just consider a track with one car per second (1 person per car) -- a very conservative density -- vs. a traditional train with five minute headways, the traditional train doesn't look so hot. Especially when you consider the effort in supporting a 40 ton car (that's just one traditional train car) vs. a 1 ton PRT car (and hopefully they could get that weight down considerably as technology improves); the PRT tracks should be way cheaper, and ultimately cheaper than roads. They couldn't actually replace roads, but they could make expansion unnecessary, or even make contraction of roads possible (e.g., removing lanes), and reduce the load on roads so they don't deteriorate as quickly.
PRT is meant to work with urban areas the way they are, not just the way we wish them to be. And the technology itself doesn't require any breakthroughs, even taking into account safety issues.
Anyway, I really hope something comes of it. Some links: SkyWeb, the PRT company that's furthest along; Citizens for PRT; Advanced Transit PRT Page for a bunch of links and academic studies about PRT.
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Doesn't it seem that there is a better solution?Personal rapid transit is already being tested in some areas. It seems this solves many of the problems with the "smart car" plus gives you other gains like:
- Fewer vehicles need to be built (most people don't spend all day in the car)
- Computer route optimization (get there quicker).
- Potentially adds economy of scale to energy consumption (each vehicle doesn't need a power plant
- Potentially simpler to avoid crashes than with traditional road-based systems.
I don't know, these are only a few benefits I can think of off the top of my head. Perhaps others can think of some more.
Of course the biggest cost is in the ultra light rail infrastructure. But, how much do we spend maintaining roads, traffic lights, etc? It seems like an elevated light rail infrastructure could be made very cost effective.
Sure, it would probably start in metro areas, but it could spread to more rural areas (where I live, we soak the feds for highway dollars) and probably save money here too.
Plus, people would be less stressed from commutes. Pedestrians could once again take over city streets. And fewer senseless deaths would have to happen. Oh, yeah, and then there's the whole ecology thing.
-Peter -
Personal Rapid TransitIt is amazing to me that even guides such as this one make no mention of the potential of personal rapid transit. Sure, no one's deployed such a system yet. But...
Given a choice, what transit system would you ride?
- A train that you have to walk 2 miles to catch, you might have to wait 15 minutes for, and which averages 15 mph over your trip.
- A car 1/4 mile away, is waiting for you when you get there, and averages 30 mph over your trip.
- A PRT car that you have to walk 1/2 mile to reach, is waiting for you when you get there, and averages 40 mph over your trip.
PRT systems have almost all the advantages of a car.
- Direct point-to-point transit. No stops.
- Average speed is higher than a car, even if 3/4ths of the trip is freeway.
- No need to share space with strangers.
- The transit system waits for you, you don't wait for it.
Every non-PRT public transit system has proven itself a failure. That is, the systems fail to attract significant percentages of commuters. And, they fail to cover operating costs by huge margins, let alone recouping capital cost.
The best public transit models available suggest that PRT systems would attract a significant percentage of commuters, cover operating costs, and eventually recoup the capital costs. It's amazing to me that no one has built such a system yet.
Then again, Atlas Shrugged. The auto industry and rail industry have a pretty entrenched interest in preventing progress. Politicians want to be able to say "it's not my fault that the transit system failed. We used proven technologies." Proven to fail, but proven nonetheless...
Support your local PRT movement.
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Re:From now on, we'll all travel in TUBES!
Americans don't like mass transit because they never had good mass transit.
That's why we need PRT! I know there are at least some advocates in the Seattle area. -
personal rapid transitEvacuated tube transports have been in science fiction since the 1960's, if not earlier. They look like they may be a good idea, but it seems unlikely to me that the airlines are going to let this happen; like Hollywood, they like to protect their market, society be damned.
Note that for local transportation, the problem isn't speed but coverage. I can't realistically take public transportation to work because it would take me far too long to get to the nearest station and because trains take far too long to get to the destination (because of a lot of stops).
For local transportation, another concept makes more sense to me: Personal Rapid Transit [1], [2]. Personal Rapid Transit consists of small passenger cabins (1-3 people) that you call to the nearest station and take to the station nearest to your destination, almost like a taxi or chauffeur. And unlike evacuated tube transports, they do not require a lot of digging or construction.
And, politically, personal rapid transit seems more promising in the short term: it's something that can be done at the local level.
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Re:They are right
IMHO, the only public transit system that could be a viable alternative to cars in the US is Personal Rapid Transit.
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Too bad
Too bad they are thinking "big 1960's style public transportation". A monorail system like Personal Rapid Transit would have been so much nicer. See also here.
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PRT seems better
While ULTra can be deployed more easily for demonstrations, for city-wide deployment, Personal Rapid Transit, a wheel based monorail, seems better: it requires much less space on the ground and is probably overall cheaper. For more info, see CPRT and U. Washington.
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Re:It's not that easyI think that's another instance of confusing cause and effect. The US used to have compact cities, very similar to Germany. And to get from city to city, you could use trains (or nowadays planes).
Urban sprawl and poor land use was made possible in the US by policies that subsidized, directly and indirectly, the automobile. Geography does not have to be destiny in this case. If gas prices went up dramatically as a result of shortages and if public funding were redirected towards convenient and efficient public transportation, people would move back into the cities. It would help the environment, reduce traffic fatalities, improve communities, and result in an overall better quality of life.
Of course, there shouldn't be a sudden change in direction--doing so would be devastating. But it could be a goal for the next 30-60 years, with gradually phased in gas prices, gradual reductions in road building, and gradual changes in land use policies..
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Personal Rapid TransitIf you search for "Personal Rapid Transit" on Google, you'll come up with several excellent sites.
CPRT is an organization dedicated to promoting these kinds of transportation systems, and Taxi2000 is one commercial system being developed. The washington.edu evaluate many different systems.
Note that it is essential for these kinds of systems that cabs are small--if they hold many people, they either need to stop a lot (=longer travel times), or they waste a lot of space and resources.
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PRT = economic issues, not engineering ones
This is a concept commonly refered to as Personal Rapid Transit (PRT), a subset of Automated People Movers (APM) found at many airports. PRT has been around for a while and has somewhat fringe supporters (like me). Edward Anderson at the University of Minnesota has generated some of the most credible system designs and incorporated under Taxi2000. In fact, Raytheon developed a full test track of Anderson's concept outside of Boston; Bostonians can visit thier Marlborough, MA facility and see the future,!
The reason that PRT remains a fringe concept is related to economic challenges, not engineering ones. Although there are claims to the contrary, the general problem is that - like all public transit - PRT require a very high inital capital outlay. In dense urban areas, right-of-way costs are prohibitive. However, just as with information networks, public transit networks generate positive externalities: the larger the system, the more useful it is to everyone.
Furthermore there is little incentive to invest in expensive public works projects have prevented the testing of a fairly unproven technology. Public agencies would much rather invest in light rail systems that they have seen before than fancy driverless systems. Also, there is no conclusive proof that these decentralized systems can sustain the high corrider passenger/hour throughputs that make public transit so desirable for really dense urban areas.
Hopefully, projects like Cardiff will succeed and PRT will get recognition and legitimacy, but this is a technology that has been kicking around for a while and - as you can probably tell - is not insanely complex. As usual, economics and public policy get in the way of interesting engineering!
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I'm surprised, too.
The Segway seems like something out of a Heinlein novel; Kamen seems like a Heinlein character. And it seems like a nifty idea to me.
I have to park nearly a mile away from my first class, and I bet this'd be a heck of a fun way to get there.
On the other hand, it seems like he already did this better with the iBot. Check out those videos. Why stand when you can sit? Why lug your Segway up stairs when you could ride your iBot?
(Actually, I'm more in favor of PRT than anything else. It solves the problem of commuting AND getting around the city, plus it's Jetson-y cool to boot.)
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PRT
For that matter, we only have a half-dozen to dozen cities where local mass transict *can* be practical.
For conventional public transit, I think that is probably correct. I mean, I live in Chicago, which would probably be one of those cities, and it's still rather crappy. They are going to spend $380 million dollars renovating 6 miles of the El. That's insane. That's a tremendous waste of money.However, I don't think things are entirely lost. I really think Personal Rapid Transit could work in most US cities. The quick summary, is small cars (one to three people) running on elevated tracks (but very small tracks, since the vehicles are light), with automated navigation (which is really easy, unlike cars, because they are on tracks).
The great part is that it doesn't require any special technology. It uses wheels, electric motors, and tracks on stilts. Nothing very expensive. Only the automated navigation is slightly technologically difficult, but I think that is quite doable. Even running at 30 or 35mph, it's still far faster than other forms of public transportation when considering the total travel time (including waiting, transfering, and walking to your final destination). In Chicago, it would be faster than driving most of the time.
People are of the perception that public transit has to be high-volume to be efficient, but that's not really the case -- if you can move people in a more parallel fashion, it can be efficient on a smaller scale. In this case, you don't stop until you get to your destination, and the cars can run fairly close together.
Sadly, governments just keep putting money into light rail, which is a complete waste. I wish it wasn't so -- but it just doesn't work, it's too slow, too irregular, and doesn't get people where they want to go.
Anyway, for someone who is interested in PRT, there's information to be found at Taxi 2000 (well, that name doesn't make sense anymore, does it?) and Citizens for PRT.
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Re:But where does the electricity come from? Dooh!I agree that electic cars seem pretty far fetched, but not so much because of the energy use, but rather because of batteries. They don't work well, they aren't very reliable, they aren't efficient, and they are horrible for the environment.
Sure, carbon dioxide isn't good for the environment. Nitrogen oxide isn't good. Hydrocarbons aren't good. But none of those is anywhere as bad as the lead and other heavy metals used in batteries. If you have a car filled with batteries, there is going to be leakage, and the batteries have to be created and recycled often, and these processes aren't great for the environment either. The emissions from electric cars are small, but particularly potent.
Electrical power has great potential, but not with conventional batteries. And I haven't heard anything at all hopeful in the way of nonconventional batteries -- perhaps, in an indirect way, hydrogen power could qualify (hydrogen being created with electricity, then being used to power vehicles).
My own preference, though, is Personal Rapid Transit -- i.e, small, automated, elevated rail cars, powered off the rail.
I think a lot of the emphasis on electrical cars is because the auto industry doesn't want things to change much. Electric cars are unlikely to be economical or effective anytime soon -- all current examples are heavily subsidized -- and even if they do, the basic economics are largely like current cars. Innovative public transit is a much better solution. Buses suck, will always suck, and are no solution at all. Subways have potential in some areas, but most development has been car-based so they won't work everywhere.
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