The WVU one where you mis represent it as being point to point between two campuses, there are actually about 6 main campuses it stops at a several other stops, so its a little more than just a go between two.

I'm sorry I tend to only comment negatively, but PRT doesn't even pass the whiff test.

Much like telecommuting, it's offered as a way for us to keep engaging in low-density sprawl. It's fundamentally impossible for this kind of system to serve large destinations with high loads - you'd need miles of platforms to serve a football game, for instance, or even most central business districts.

Because you're moving a vehicle, you have right-of-way costs. These costs are astronomical in an urban area - and about the same no matter what you put *in* the right-of-way, so it makes the most sense to use the space for high capacity transit.

These systems have existed, like monorail, since the 50s and 60s - in about their current form. The reasons they haven't gotten traction have nothing to do with how "green" they are - they're simply a horribly inefficient use of space. Oh, and if you dig in, you'll find most of these systems are limited to some 25mph. When you consider entry/egress times (and getting to the station), the trips you can reasonably serve at 25mph are already being served - with bicycles.

I'm sorry I tend to only comment negatively, but PRT doesn't even pass the whiff test.

Once again you fail to even try to engage your imagination, just go right for the "it sucks" comment.

It's fundamentally impossible for this kind of system to serve large destinations with high loads - you'd need miles of platforms to serve a football game, for instance, or even most central business districts.

That doesn't make any sense, since the vehicles are smaller, could be stackable, and needn't have all the moving space requirements of automobiles. You should research the possibilites of the technology (much like your narrow view of telecommuting missed obvious aspects of it that have little or no downsides and plenty of upsides) and come to understand it before passing judgment on it.

In the absence of new ideas, the old ones will persist. All your naysaying does is help perpetuate auto dependence and sprawl, even though you decry them.

Be a part of the solution and engage your imagination and positivity.

they're simply a horribly inefficient use of space

Like I said, you don't know what you're talking about. A good system has much better throughput for a given footprint than automobiles do, and if it's done well, pretty much better than any technology.

Oh, and if you dig in, you'll find most of these systems are limited to some 25mph.

So? That's not some absolute limit on the speed for such an idea.

When you consider entry/egress times (and getting to the station), the trips you can reasonably serve at 25mph are already being served - with bicycles.

The average speed of a city bus hovers around 12 mph. The average speed of all automobile traffic is 30 mph.

Most designs have them within 5 minutes walk of people. So assume a 10 mile trip on a PRT system with maximum walking time on both ends. That's 18 mph. Unless you're one heck of a bicycling athlete and you have a dedicated pathway that goes directly from where you are to that destination, there's no way you're going to average 18 mph on a bicycle over a 10 mile distance, and even if you were capable of it (which in a city situation means either running a lot of stop signs and red lights and/or going about 25-30 mph between stops), you would be soaked in sweat by the time you got there.

Fact is, regardless, almost no one is going to make that trip by bicycle, certainly not in less-than-ideal weather. That technology has been around for a century and a half and it never gets past 1 or 2% modal penetration.

The impact of any transit mode on land use depends on the accompanying land use policy. The long range outcome of PRT is that it would allow efficient rapid transit to any part of an urban area -- i.e. just about anywhere would be within walking distance of one of the small stations. Thus rapid transit -- whether LRT+PRT or all-PRT -- would be available more like a public utility, and transit mostly drops out as a planning consideration. Separating transit policy and land use policy means zoning can be done according to what makes the most sense for each neighborhood, groups of neighborhoods, and the city as a whole. Conceivably, with availability of a PRT network more areas of a city could be rezoned to be more sustainable. Just using conventional rail effectively limits such improvements to the areas in each station's rideshed.

By the way, 25mph is fast enough if you don't have to stop until you get to your destination. Thus, each PRT vehicle can make many trips per hour, and the overall network achieves high capacity.

"Much like telecommuting, it's offered as a way for us to keep engaging in low-density sprawl. "

People will look for ways to live in "low-density sprawl" because that, to them, is an attractive lifestyle and urban packing isn't.

To redesign the culture to make everyone highrise dwellers just isn't going to play.

"It's fundamentally impossible for this kind of system to serve large destinations with high loads - you'd need miles of platforms to serve a football game, for instance, or even most central business districts."

Easier to design than to design parking for full sized automobiles. Which we already do.

No reason why these 'pods' need be individually owned. Just 'rented' as needed. With good IT we can minimize the number sitting empty at any given time which would greatly cut down the required parking spaces.

Big events? Pods stop and let people off and then continue on to another customer or parked on low cost realestate.

"Because you're moving a vehicle, you have right-of-way costs. These costs are astronomical in an urban area - and about the same no matter what you put *in* the right-of-way, so it makes the most sense to use the space for high capacity transit."

These pods are high density transit compared to individual cars. And can be stuck above existing highways just like the Bangkok SkyTrain.

"These systems have existed, like monorail, since the 50s and 60s ... most .... limited to some 25mph."

Makes you point bogus does it not? Some are capable of going higher than 25mph so there is no 25mph limit on what could be built.

"When you consider entry/egress times (and getting to the station), the trips you can reasonably serve at 25mph are already being served - with bicycles."

Sorry, one does not put a family of four on a bicycle and ride across town in Chicago in winter.

Getting to/from the station. Why not individual owned pods that you can take from your garage and 'pilot' to the nearest terminal where you get on the tracks and relax until you reach your destination terminal at which point you take over active control once more?

Or get out and have your pod move on its own to a parking garage?

People want to live in detached houses with some lawn/garden space. People want to travel without having to be jambed up with people they don't know.

Might as well design systems for those desires if you want them to sell.

If anyone's interested in learning about new ideas in transportation technology, Jerry Schneider has a great site for it.

http://faculty.washington.edu/jbs/itrans/

I agree with anonymus, PRT does have merits.

If a small-medium PRT network starts operation somewhere, everyone will see its advantages and they will start sprouting all over the developed world.

The podcars.org link doesn't seem to be anything related. Is there a site you meant to direct us to?

Sorry about that extra 's' - now it's better.
Also, vectus.se
has an English-language option, though not as up to date as the Swedish.

i think this is a great idea. i would love to just get in my pod and tell the computer to take me to work or take me home. i'm sure they could find a way to make "astronomical right of way costs" work. and parking too. if u really think about it, even TRY to think about it... u'll come up with something. and if u cant, the best minds in the country can come up with something. -_-

and one reason that trolley systems and other mass transit systems have failed- car companies. gm bought up the trolley systems early on, and phased them out. if u just let the market make its own decisions, we just might get green transportation systems... hint hint, who killed the electric car.... its not cuz such systems are horribly inefficient in general. its that the evil greedy companies couldn't care less if the world burns in hell so long as they make a buck. THINK ABOUT IT. whoever made that negative comment earlier really didn't put any thought into this whatsoever.

I'm a passerby here. I often comment on PRT (aka "podcar") discussions.

Ben Shiendelman is a long time critic of both monorail and PRT. I've found that he has a fundamental misunderstanding of how PRT works. His comments above are just not correct:

"you'd need miles of platforms to serve a football game"

No, you need multiple stations. PRT stations can go anywhere - a stadium could theoretically have a station at every gate. So instead of "miles of platforms", you have, say 10 smaller, 8-pod gates spread out. around the stadium. Ben's preferred choice is light rail, so he tends to think in terms of one huge platform (which rail requires) rather than many smaller ones.

"Because you're moving a vehicle, you have right-of-way costs."

ROW costs are always a concern, but PRT consumes much less area than a train. The pods are small, guideways are slim (usually ~ 3ft wide), and stations are minimal. The only impact on the streets themselves is generally a support post every 50 feet. That's a tiny fraction compared to (say) at grade light rail, which consumes entire traffic lanes.

"These systems have existed, like monorail, since the 50s and 60s - in about their current form."

This is very deceiving. PRT has existed in theory since the 60s, but only one almost-PRT system was ever built - in Morgantown VA. That's it. It's become much more practical recently, now that technology has finally caught up to the theory.

PRT is largely untried in a real setting, which is the main reason why most cities reject it outright. The Swedes are to be admired for taking a risk on PRT. It's a good risk - the potential payback in terms of transit costs and environmental impact is huge.

"they're simply a horribly inefficient use of space."

Nonsense - it's one 3ft diameter support post every 50 feet. Are raised power line also "a horribly inefficient use of space"? Compare to 20-foot wide rail lines.

"most of these systems are limited to some 25mph. When you consider entry/egress times (and getting to the station), the trips you can reasonably serve at 25mph are already being served - with bicycles."

Nonsense. PRT is nonstop without transfers, meaning the average trip time is MUCH shorter than the average rail/bus commute. Look up average travel times for rail lines, and they almost never reach 25 mph - more like 16 mph average with all the station stops - and that doesn't include transfers.

The Swedes are doing it absolutely right, by phasing in PRT to blend with existing options. This approach allows PRT to ramp up without disrupting existing commutes. I'm a big fan of mixed-mode PRT with buses or existing rail lines, because:

(a) Existing bus/rail routes can maintain capacity as the PRT system is gradually built up.

(b) PRT can make bus/rail much more efficient, by allowing transit planners to eliminate low density routes and times. Imagine being able to run buses only at the very highest peak demand times, how much that would save in both cost and emissions. In time, as the PRT network is built up, capacity will grow in kind and the buses will be even less necessary.

I can envision a future where a well developed PRT system serves all off-peak demand and a good portion of peak demand, allowing trains and buses run the highest-demand express routes. Example: an express train linking downtown with the airport, and a PRT network filling in the gaps. Buses could provide overflow support on demand (i.e. after a ballgame). And transit becomes so highly available and ubiquitous that people leave their cars at home.

Is it a realistic future? Who knows? Only time will tell. But I admire the Swedes for taking the initiative and risk, and I truly hope they are rewarded.

Hate to say this, but nothing beats a car and nothing will. Nothing beats the freedom and convenice you get with a car. As for the fuel emissions, global warming stuff, that should take care of itself.

Mass transit vehicles suffer from some of the same problems cars do: a lot of the energy they use is consumed in moving themselves around.

Even when a 1-ton car carries 4 beefy (250 lb) passengers, only 1/3 the total weight is payload. If it carries only the driver, only 11% is payload.

I don't know what the data for a bus/trolley is, but I'm betting it's not dissimilar. Busses/trolleys, to be sufficiently convenient, must run often enough that they run only partly full nearly all the time. And they are heavy suckers.

Consider a PRT system made of lightweight materials (e.g. carbon fiber) in multiple sizes (1 person, 2 people, 4, and 8 let's say) that runs on rubber tires in ordinary but dedicated streets, guiding itself by induction along buried wires, with computer-controlled radar to control the speed and gps routing, and a 'dead-man' mechanical braking system to prevent loss-of-control accidents.

why would u even read treehugger.com if u were as narrow-minded as to say that

"Nothing beats the freedom and convenice you get with a car. As for the fuel emissions, global warming stuff, that should take care of itself."

could u be any more stupid and short-sighted?