Monday, August 13, 2007

Untested and unproven, you just have to build it

Mesa AZ - A Personal Rapid Transit system (PRT) is being pushed for by the creators of what is called SkyTran. It is a futuristic transit mode that utilizes small passenger pods on demand rather than running on a fixed schedule. Seeing the computer graphics of what the SkyTran system is to look like, I started humming the theme from the Jetson's.

Currently in Mesa, the city is in the midst of a long term transit analysis and exploring various transit options for the future. Supporters of the untested and futuristic concept, built by Unimodal, want it included in the analysis and as the focal point of the study. Mind you, the analysis will help steer the city's future transportation planning.

To include PRT as a focal point of the analysis is simply ludicrous. PRT systems are not designed for mass transit, period. They are incapable of handling large passenger loads and are more suited for places like universities and large company complexes with many buildings spread out over hundreds of acres.

Wild and unsubstantiated claims on the SkyTran website such as SkyTran being able to "totally eliminate commuter congestion in any city" is literally false advertising and a complete misrepresentation of the product. Another claim of "SkyTran can END road congestion, car accidents and automobile air pollution" also state the impossible.

Where are the actual studies proving these claims? Not in-house computer projections or "what we believe" press releases but the actual independently conducted case study that proves beyond a shadow of a doubt that SkyTran will totally eliminate 100% of the traffic congestion in any city? I already know the answer, there isn't any such study.

The author of the azcentral.com article, Jerry Spellman who is a volunteer coordinator for Unimodal/SkyTran (and would make a tremendously successful used car salesman), touts SkyTran as the cure-all to Mesa's transportation problems. It can make a profit that can be shared with the city, Spellman proclaims. The same claims were made about the money losing Las Vegas monorail. Unlike the Las Vegas monorail however, Spellman wants the SkyTran system as the focal point of Mesa's transportation future. An untested and unproven mode of transportation that is full of the promises of Utopia if only it can be built.

Another claim from the makers of SkyTran is that people will be traveling around at 100 mph around the city. If you sent someone in one of the passenger pods for a 4 block ride, you would not get it to 100 mph. If you did, that person would be thrown back and whipped forward as there is insufficient space for speeding up and slowing down safely. You also would have hundreds of switches and sensors along the line to allow the PRT pod to bypass stations and other pods. One tiny error in any of the millions upon millions of calculations per second the system must do or a small system glitch, as the driverless pod is whipping around the city at 100 mph, could easily spell disaster.

The SkyTran website reads like a science fiction novel. Between the wild claims being made, bashing every other mode of time proven technology and fancy computerized graphics, one gets a clear vision of how Utopia is seen through their eyes. I really had to fight to convince myself that the SkyTran site wasn't a satire site but a real site aimed at convincing people that SkyTran is the answer.

"No ongoing taxpayer subsidies needed!" exclaims Spellman in his article. "A load of bull!", I exclaim here. As with the Las Vegas monorail, more tax money will have to be pumped into it as time goes on. Simply put, SkyTran will not even remotely pay for itself yet alone bring in the big profit that Unimodal states it will. There will be no sharing of the windfall with the City of Mesa.

To pay for the operation, you will either have to charge a ridiculously high amount to ride it which will keep most people off of it (and you still won't meet the operating costs as the higher the price, the less will ride) or you'll have to be subsidized by the taxpayer. That's basic Mass Transit Economics 101 in this day and age, Jerry.

Given that SkyTran is envisioned by Spellman as the central core of Mesa's transportation system, there is no way in hell that more tax money won't have to be poured into it. Your not going to be able to have SkyTran be the core system while charging $25 a ride. Your going to have to get the price down to existing transit fares which will mean a big drain on the SkyTran finances. To make up for the loss, you'll be heading to city hall to plead for more tax money to keep the system running.

What disturbs me the most is that the SkyTran sales pitch is exactly what tax and spend politicians love to bite on. Something unproven, sure to skyrocket in price and is touting the "green" message that these politicians blindly follow like mice following the Pied Piper. If Mesa doesn't bite on the SkyTran proposal, they'll start hitting up other cities to fund their PRT folly.

If SkyTran is all that it claims, where is the test line on company property to clearly show everyone the concept in a full scale working model? So far, all I see are visions of what it should be with wild promises being made. There is a huge difference between theory and reality. So many things work in theory but in reality they fall far short. In theory, even some of the greatest blunders of mankind looked great on paper but failed miserably when unleashed on the public.

This isn't the only PRT proposal floating around either. There are a few others out there by other companies. An ongoing proposal in Minnesota as well as one in Washington state to mention two I personally am aware of. Each one sounds the same however, build it and all your transit problems will be forever solved. None have been tested nor have any been willing to build a test line completely on their own dime to prove their claims. These companies all want to place it as a central core part of the existing transportation infrastructure. As I see it, this means that they have an escape if things go wrong and can unload the responsibilities onto the government if it goes belly-up.

Mesa politicians should not even think about including such an untested and unproven concept such as SkyTran into the transportation analysis. The residents of Mesa need to make that clear to their elected officials. If built, it won't save money, it won't be safer and it definitely won't cure your transportation problems. You'll end up with an expensive white elephant that even more of your tax dollars will have to be sunk into just to keep it running.

9 comments:

A Transportation Enthusiast said...

Your comparison of PRT to the Las Vegas monorail shows how little you know about PRT. Monorail is basically elevated light rail, and bears almost no resemblence to PRT. The only similarity between monorails and PRT is that they are both elevated. Comparing PRT to monorails is like comparing trains to cars because they both have wheels.

SkyTran (and PRT in general) is an untested concept with great theoretical potential. Is it a panacea? No, of course not. Will the first implementation be problem free? No, of course not. But once you understand the technology and the mathematics, the potential upside is huge.

It's a big risk, yes, but the potential reward is also great. Contrast this to surface rail or buses - two options that are well tested and proven incapable of reducing congestion in US cities. Given the proven lack of effectiveness of other options, I'll take the high-risk-high-potential-reward of PRT any day.

One other point: the existence of a good public transit option like PRT would enhance ALL transit. Buses or even streetcars could be used during the high-demand to augment the PRT traffic, and commuters would be more apt to use them because PRT guarantees they will have service back home no matter when they leave. In turn, buses and streetcars would not be required off hours when demand is low (PRT is available 24x7), thereby reducing the cost of operating these line haul modes at times when they would be nearly empty. In effect, the existence of PRT might make rail and buses more attractive and economically feasible.

The point of all this is: if reducing congestion is the goal, then creative solutions that include a flexible option like PRT are necessary, because no existing option has ever been able to do it well (at least not in the car-centric US). And if something like a SkyTran is successful built and deployed, it enhances all public transit options.

(Personally, I prefer other systems - Vectus is my current favorite PRT effort - but I'm also intrigued by SkyTran's use of Inductrack instead of wheels...)

RDC said...

Your right that comparing the technology between PRT and the monorail is like comparing trains to cars but I wasn't comparing the technology.

I was comparing the claim that "no more tax money will have to be pumped into the line once it's built".

The Las Vegas monorail people made the same exact claim that SkyTran proponents make. That is once the initial public outlay to build the line is done, no more tax dollars will ever have to be pumped into the project since it will make money. Any extensions would be funded from the profits of the line.

Well that simply isn't the case in Las Vegas. There is no hard proof that PRT will make a profit either nor that more public money will have to be pumped into it once it's up and running.

In theory, you can make any assumption you wish to make a case. The key is the real world. In theory, the monorail was to be raking in millions of dollars with throngs of people wanting to ride but in reality it is losing millions and ridership is dwindling and never came close to meeting projections.

SkyTran claims are based more on assumptions than on fact. An example: It is assumed most people will give up their cars to ride it and thereby eliminate traffic congestion. Getting most people to give up driving will the only way you will completely eliminate traffic congestion. In theory, sure but it ain't gonna happen in the real world.

A Transportation Enthusiast said...

Yes, but you are comparing apples to oranges. The Vegas monorail is a completely different system than SkyTran or any PRT system. The vast differences between PRT and monorails make any comparison invalid.

Monorails suffer from the same problems that plague any line-haul transport mode:

(1) There is always a trade-off between service frequency and cost, so service must be cut back during off peak times. Set the frequency too high, and your costs go up as trains are running nearly empty; set it too low and passengers find a cab instead. It's a constant balancing act - and it's the single biggest weakness of line haul transit (IMO).

(2) Limited destinations and many stops - if it's not on the "line" then you have to transfer, and even if it's on the line, you have to stop at each station. PRT is quicker, more flexible, and non-stop.

(3) The infrastructure required to support trains is MUCH bulkier (read: more expensive to build) than that required to support lightweight pods.

These are 3 very significant issues that plague monorails (including the Vegas monorail) but which simply do not exist for PRT.

And, in fact, because PRT does not consume resources when it is not being used, it is much more immune to lack of ridership. If nobody rides the PRT, vehicles don't move, meaning they don't consume energy nor accumulate wear. An unused PRT system is a very small drain on operational costs. Compare this to trains and buses, which must move constantly to provide service.

One benefit of this is that PRT is available 24x7, but another hidden benefit is that fares are not so constrained by the need to fill trains or buses.

Example: if you set a bus fare too high and the buses aren't full, you lose money because the operational cost to push the bus up and down the line is the same regardless of how many are onboard. So bus fares must be low enough to make sure the buses are relatively full, but high enough to support operational costs. And in many cases, even the absolute optimal combination of service frequency and fares does not make enough to cover costs.

For PRT, you set the fare based on operational costs, and if fewer people ride, then so be it - fewer riders equates to lower operational costs anyways. Now, of course, there is somewhat of a balancing act because idle PRT operations are not completely free (and there's always the construction bonds which need to be paid off from fares), but the fact is that the need to minimize fares to attract riders is MUCH less significant for a PRT system, by virtue of its "move only on demand" characteristic. So there is much more leeway in setting the fares to ensure profits. Indeed, setting the fares relatively high at first might be a big benefit, because it would minimize the crush and maximize profits during the initial "breaking in" period - and fares could be lowered later if desired. Such an approach would be fatal for a monorail, which must always fill the moving train.

So, the monorail is more expensive to build, and provides less slower, less comprehensive, less frequent service than a PRT system would deliver, and is more susceptible to higher costs due to low ridership - so the fact that the Vegas monorail failed is really irrelevant to the PRT question...

Will PRT make money? We won't know that until one is built and we get real world data, but it is invalid to just assume it will fail just based on the failure of a completely different type of system with a completely different cost structure.

RDC said...

Actually your missing the point of the comparison completely. It is the same old tired argument that proponents love to toss out. It doesn't matter what mode it is but you always here something like "it will reduce or eliminate congestion" and/or "it'll reduce costs" based on various computer generated studies done prior to the building. In reality, it increases congestion and costs soar. Apples and oranges? It's still fruit and the comparison of the rhetoric is valid.

You really have no idea what PRT can do beside the theoretical idea of how it should work in a perfect world. To be honest, neither do I but I have experienced enough white elephants to know one when I see one. While I agree we won't really know it's real potential until something is built, I must ask why does the first test have to be the focal point of the city transit infrastructure?

Wouldn't it be better to actually build a test line like they were required to do for Skybus in Pittsburgh during the 1960's so that it could be tested and evaluated without using the city's transit infrastructure as the guinea pig for a theoretical experiment? If such a test line was done at a fair ground for example, it could prove itself as a viable transit solution with plenty of time for testing and enough people for capacity testing while not putting the transit infrastructure at risk.

To put an entire city's transit infrastructure at risk on what is still an unproven and untested product is just poor transportation management and plain insane. SkyTran is just that, untested and unproven and I don't give a rat's rear end what the theory states. Theory is not reality. What happens if it doesn't live up to the promises as often happens when theory enters reality?

Have you actually even looked at the SkyTran website and the wild claims they make? From your comments so far, it doesn't appear that you have. One claim is that it will "totally eliminate commuter congestion in any city". Come on, do you seriously believe that to be true? If so, your wearing blinders.

These wild claims on the SkyTran site are what will be used to sell SkyTran to some politician that is just itching to spend taxpayer money on a pork project.

Again, apples and oranges in your words but light rail proponents make a similar claim. At least they tone it down a bit and say "reduce congestion" rather than "totally eliminate commuter congestion". Tell me, how do SkyTran officials know it will totally eliminate congestion when they haven't gotten it off the drawing board? Computer models? Please, I can get my computer to tell me 1+1=3 if I set the parameters of the program to tell me that.

And yes, I do know the difference between PRT and other transport modes. I've also lived through and witnessed personally the Pittsburgh Skybus fiasco that was an untested and unproven technology (but at least they built a test track at a park to test it without foisting it off as part of the transit infrastructure). Many of the same claims were made back in the 60's with that as are being made today with SkyTran. Apples and oranges, I know but the comparison is still valid as it is the rhetoric being said which is being compared.

New technology doesn't always mean better technology either.

A Transportation Enthusiast said...

Well we already know that the same old transit solutions will never work. Adding roads might work for a while, until your city is totally paved over and looks like a giant cigar bar with a cloud of muck hovering overhead. Adding trains or buses will almost certainly not solve the problem, and may make it worse.

So what's your solution? At least PRT designers are trying something different, not throwing their hands up and saying "congestion and smog are part of life, deal with it or move to the country..."

Cities fear taking a risk with something like SkyTran (or PRT in general) but the fact is, they are taking just as much - or more - of a risk by doing the same old same old: highways that tear apart a city, and trains and buses that few people ride. In many ways, these "no risk no reward" solutions are actually riskier something like a SkyTran, because we already know they're not going to be able to support growth beyond a certain point.

So I'd be eager to hear what your solution would be. Certainly not more highways?

Avidor said...

Careful, if you don't agree with A.T.E., he'll pester you forever... maybe even devote an entire blog to you.

A Transportation Enthusiast said...

Hello Ken! We are having an intelligent debate here... are you ready to join in or are you still afraid to debate me? :-)

Avidor said...

No thanks... I don't debate anonymous people on the internet who say stuff like this.

A Transportation Enthusiast said...

Ah, yes, I forgot - you can dish it out but you can't take it.

C'mon, don't be afraid, Ken! I won't bite! I'll even type with one hand tied behind my back, how's that?! :-)