Saturday, December 12, 2009

Skytran - future transit option?

A friend on Facebook pointed out the Skytran to me recently. It's quite a fascinating concept transit system, and the Skytran home page is worth your time to check out since I really don't think I could describe it with words that do it justice.

My initial thoughts on this concept:

First, it's definitely a much better option than traditional rail mass transit. As Randal O'Toole has argued (here, for example) rail mass transit is terribly inefficient(in cost per passenger-mile) and inflexible when compared to buses, for example, and also that it primarily exists because of perverse incentives in federal mass transit funding.

Second, slightly more negative, is that NASA is the primary researcher mentioned. As much as they've come up with cool technology I'm skeptical of their ability to either meet a consumer demand or develop and implement anything as cost-effectively as a private sector R&D organization.

Third, to be a serious alternative to the private auto, the Skytran would have to be flexible in its routing (i.e. each vehicle could go to any boarding station on the metropolitan Skytran network without the rider having to transfer from one vehicle to another).

Fourth, as simple as erecting utility poles is, it's formidable and expensive to replace them all across a metro area. You'd also have to plan on making major upgrades to the local power grid to be able to supply sufficient electricity for the Skytran system. Additionally the cost of sufficient vehicles to meet demand might add a lot, though certainly not as much as the tracks themselves.

Fifth, making the vehicles available when and where they're wanted is a challenge as well. Demand for highways, parking spaces, mass transit seats, taxis, etc. - modes of transport that already exist - is an order of magnitude higher at some times of day and days of the week than others, and is also affected by predictable anomalies like sporting events and concerts. Skytran systems would have to make some tradeoff between purchasing vehicles that sit unused much of the time, or increasing waits during high demand times.

Related to that, and I think this is potentially positive, the Skytran rider could much more easily be charged based on their point of origin and time of day than a highway user or bus rider. Until point 6 takes effect...

Sixth, federal and especially local politicians would love to impose their preferences on such a system. It's not farfetched to imagine generous handouts to transit unions, arbitrary route and fare mandates/restrictions, and various costly add-ons that wouldn't be chosen in a free market.

1 comment:

  1. Obviously you think pretty deeply about mass transit. I can shed some light on your issues.
    NASA did little of the original work though they may do more in the future. None the less,
    I agree with you that NASA has both come up with some very advanced technology but they've spent a heck of a lot of our money doing it. We'd hardly call them attuned to mortal concerns on the planet. But heck, maybe its time they CHANGE and come down to earth! This is a good opportunity for them.

    "Third" A Skytran vehicle can go non-stop to any station on its network. Stations will likely have differnt spacings depending on density of riders, but stations every mile on a 1 mile grid is an economically viable architecture.

    "Foruth" yes its expensive building Skytran, its just a lot cheaper than building roads, dedicated bus routes, light rail or subway. The operating costs are also smaller than for any of those other systems. The guide3way doesn't get potholes or have to be snow-plowed in the winter. There's fewer people needed to maintain it than the other systems and less wear due to the maglev and electric motors so maintenance is lower. Electricity is 0.1KWH per vehicle mile. That is so small that its actually possible to power the system off of 2 foot wide solar panels on top of the guideway making it pretty much the only net zero energy transportation system. Even if we go to electric cars, Skytran is considerably more efficient and will use much less power than plug-in electrics. (ligher, no stop & go, more aerodynamic, more efficient regen from braking, less rolling resistance) As far as vehcile costs, they are cheaper than cars because: they're much lighter (about 300 pounds) don't require batteries, have very few moving parts, just one door, only 2 seats, don't get into accidents, etc. Also each car can be used a much higher percentage of the time than private automobiles so overall the cost of the vehicle fleet is MUCH cheaper than our fleet of private cars.
    "fifth" Yes, there are the trade-offs you mention, but the trade-offs are better than the alternative. Parking lots and wait times to get out of a major sporting event can be long no matter what you use. (err, exept watching it at home on TV!). Because SkyTran is a guideway where the cars are automatically drivin, the system can "rebalance" itself to shuttle empty cars where they're needed. Because Skytran is so efficient this "empty shuttling" isn't as expensive as cars (as in empty Taxi cabs) or buses or subway trains.

    "Sixth" This isn't really a criticism of SkyTran, every mode of travel or actually any large project anywhere is subject to the whims of policicains, unions, etc. Certainly cars, rail, planes, bikes, walking on sidewalks and boats all have been. Since Skytran is cheaper than the above transportation systems (OK walking and biking SHORT didstances is probably cheaper :-) it ought to be easier for most players to adopt it than improvements to the other transportation modes.

    The issues surrounding ANY transportation system are complex. You nor I can hope to cover them in a few paragraphs. Your skepticism is well justified and well articulated. I hope I've been as clear in answering them though I know that for conciseness sake, my answers are surely incomplete.