Sunday, November 1, 2009

57> Roads, Roads and more Roads

A note about this post… One of the problems with a blog format is that the passage of time buries old posts more and more deeply, and with them, ideas that were considered foundational. After 57 posts, how do new readers even know what I’m talking about? I am caught between trying to build on previously explored concepts and not becoming so obscure as to turn new readers away. What follows is not exactly new to some of you, but will be to many. I think it is important to try to get everyone on the same page.

PRT has been aptly described as “The Physical Internet.” (Bill James, JPods) But what really fits the bill is the present road system. They don’t call the Internet the “information super highway” for nothing. Our road system has become an amazingly pervasive network, and, coupled with cheap fossil fuel and advances in cars and highways alike, has created the most mobile population that the world has ever known. The system works so well that very few people ever consider the negative implications of continuing its expansion. Also invisible, to most of us, is its costs. In fact, the only thing that wakes us up at all is when the system breaks down.

Roads have been built on tradition, more than real analysis of transportation design requirements. Paths became trails, carts needed flatter wider trails, faster wagons needed smoother roads, then there were cars, then trucks. Now our little paths need to support 80,000 lb. vehicles and can be hundreds of feet across.

It’s not that roads are cheap. They are not cheap to plan, to fix, to clean, to patrol, to connect to, drain around, to elevate, to bank, to clear from accidents, grade for, purchase land for, license drivers for… I could go on… But the costs are so buried in established practices that we don’t even see them anymore. We can’t even imagine a world without that money leaving our collective wallets. We not only lose millions of hours each day in traffic, we perversely pay more for roads when we are stuck in gridlock, through taxes levied on the gas we are wasting. (A little footnote here: As cars become more fuel efficient, these funds for road improvements decrease. Eventually the cost savings from owning a more efficient car will need to be offset by higher taxes.)

We can’t do without a sophisticated transportation network. That Genie cannot be put back in the bottle. But the developing world (and the world at large) cannot afford to see this concrete network model unfold to its logical conclusion.

Suppose we could start all over again, but with modern technology and environmental awareness. Knowing what we know now, were we dropped onto a primeval planet, and had to build a new network from scratch, would we begin by terraforming the habitat with bulldozers and dynamite so that foot thick ribbons of concrete could connect parking lots with each other, as the preferred way to connect structures, goods and people? Wouldn’t it be cheaper both in the short term and long term to plant some pylons in the ground to support pre-fabbed sections of guideway or track? (Don’t forget the environmental impact of changing drainage patterns and the habitat segmentation that roads create.)

I acknowledge importance of truck access. It’s pretty hard to build a house without it, much less a building. Yet truck access also shapes need and development. First comes truck access, then comes deforestation. Soon to follow are deliveries of heavy, bulky materials that can only be delivered by, of course, truck. The economics of suburban sprawl are directly tied to the economics of our “physical internet”. I do not pretend that this hypothetical alternative transportation network would be equal or advantageous in all respects. We have become used to having virtually all addresses accessible by very heavy equipment, even hundreds of miles from city centers. Would the pioneer inhabitants of our brave new world choose to abandon the road paradigm altogether? I doubt it, but I can’t imagine that they would want to revisit all of the cost and effort and environmental damage that went into the present system either, were a viable alternative available. I think they would look at the road for what it is, a great way to deliver truly heavy freight beyond shipyards and train yards, but not such a great medium for a one-and-only, all pervasive “physical internet”.

So what would make a great “physical internet” in this brave new world? Four things.
1. Very cheap. (in materials, construction costs, and upkeep)
2. Very versatile (as many applications as possible within the constrains of it’s form)
3. Elevated, both to unlock the value of the land below. (economic, aesthetic, environmental) and to minimize the amount construction that needs to be done on-site.
4. Very, very efficient, meaning fast, low energy, high though-put.

There are many iterations of PRT/PAT, but the two projects currently under construction, (ATS’ Heathrow Airport and 2getthere’s Masdar City ) projects are based on the familiar concept of the road, although it is usually described as a “guideway”. I hope these companies have a firm grasp on just how poorly their "guideways" stack up, on the basis of the above-mentioned criteria, compared to other designs that have been put forth. With any luck they already have “second generation” plans in the works. At the moment one is forced to compare their systems’ performances to that of user-driven electric vehicles on a similar guideway. I acknowledge that “going electric” and reducing lane widths is a major improvement. But why not just widen bicycle paths or paint off sections of road for small electric vehicles, private and/or rented? What is the point of having vehicles do something automatically that people can do as well or better? The value of automation comes when machines can vastly out-perform their human counterparts. It would seem that weather, or pedestrians, for example, would tend to keep automated roadway based transport forever slow for safety reasons.

Every journey begins with a single step, and the people who control the money are rightly conservative, and roads are familiar and proven, so I heartily endorse these projects, and congratulate the companies for landing the contracts. The driverless automation part, though less than essential on roads, is an absolute requirement for raised thin-guideway or rail systems that need sophisticated traffic management. All PRT efforts help develop that key element, so these companies are providing a needed boost. But let’s also keep our eyes on a bigger prize – a next-generation “physical internet” that is vastly better than what we have now. Only a system that demonstrates overwhelming superiority (by the previously mentioned criteria) will have the ability, in a free market world, to significantly impact our longstanding transportation traditions within our lifetimes, and so deliver the benefits that such a system could bring to all of humanity.

4 comments:

cmfseattle said...

note that railways turn a profit. before logging trucks, there were many different methods of hauling lumber out of forests. could you design a track made out of timber? shay locomotives could climb steep grades and take water from streams.

we no longer need flanges, but we should have a smooth pathway that sits at least a few inches above ballast.

on google books, you can find a preview version of the latest APM conference papers. (not sure about the link, if you feel so inclined maybe you could piece it together) http://books.google.com/books?id=yxtIIIhHwnMC&pg=PA436&lpg=PA436&dq=How+to+Design+a+PRT+Guideway&source=bl&ots=li0yrNz-FD&sig=tVqWjR8qfxeK4faqNfpAOKlJLyQ&hl=en&ei=L_zjSoKgDpO-sgORmMywBA&sa=X&oi=book_result&ct=result&resnum=10&ved=0CC8Q6AEwCQ#v=onepage&q=How%20to%20Design%20a%20PRT%20Guideway&f=false

there are a few pages missing (copyrights). ULTra's experience with surface guideway engineering is described, beginning at p.450. basically, roads are not necessarily simpler or cheaper.

begin with the railway paradigm of two rails, but fill in the area between them (in fact, the crossties could be placed between the rails, rather than under them). but how do you transition to elevated segments (especially if they're guarded from the weather)?

seems to me, this is where dual mode would come in handy: a suspended design would avoid the need for a ramp to touch the ground. car pallet-equipped bogies could be used to pick up Smart-sized electric vehicles, while dedicated passenger cabin-equipped bogies handle the single mode trips.

i don't think most folks would want to live in tree houses. but i do think tracked eqpt. could be hauled in on low-cost, at-grade guideways.

so, back to the forest: could you build it out of timber? yes, i think that at-grade guideways could be made from ripped logs (ballasted with gravel). replacing the timber with steel shouldn't pose too much of a challenge. later, instead of four-lane arterials or big highways, suspended guideways of steel could handle longer, higher-speed trips.

Dan said...

Hi cmf….
It always surprises me how I can be, in my own mind, saying something clearly, and yet someone else can come up with a very different interpretation. I now realize that in my own mind I was not thinking of this primeval world as neither flat nor dry nor free of snow…Clearly, in the desert, for instance, the way to go would be on the ground. I also did not mean to suggest that the only options were primitive ones. I was assuming they could get stuff “spirited” in, and should have said so.
I did mean to suggest that, in a fresh start scenario, there would be complications arising from greater environmental awareness. As soon as a proposed road was mapped, the people would realize they would be altering the watersheds. If they follow modern EPA rules they would need to prevent run-off of mud during construction. They would want to look into the effect of the segmentation of habitat. If the ground was hilly and the earth was root-filled, that first bulldozed gash in the land would give pause for thought, especially considering the wholesale changes that introducing a ground based standard would create down the line. Roads are essentially bad for the environment. Period. I was just saying that there is not really any intrinsic reason why that would be the way to go. Think of the elaborate trestles of the first railroads. That, in a hilly region, is way more environmentally responsible than blasting and bulldozing through everything. In a snowy region, one has to ask if it is really worth setting up a network that requires plowing in the winter. In my part of the country we have swamps and floods. Destruction of wetlands for roads is a price that our “settlers” would want to weigh carefully. After weighing all of these costs, I think a light, elevated rail might look pretty good. No, they wouldn’t live in trees, but they would probably understand the importance of building up and not across. Someday hopefully tax codes will favor minimal footprint building and remedial landscaping.
There was a time when there where schools of dolphin numbering in the thousands right off of the New Jersey shore. There were flocks of birds that could blacken the skies for hours, and herds of bison a hundred miles long. But every generation has lower expectations than the last. Many years ago, down in Veracruz, I discovered a little dirt road that led inland, into the mountains, to beautiful jungle paradise. Monkeys, parrots, orchids, waterfalls, the works. I brought my wife there a dozen years later and it was a moonscape. Not enough grass to make a half bale of hay as far as the eye could see. Too bad they made that road…and too bad that the new generation is clueless about the loss. In Houston, we have altered our local climate with pavement.
I guess my question about what would these colonists would do is mostly rhetorical, because the more we understand the true costs of roads, the more expensive they become. The inherently reduced footprint of a raised system starts looking better and better.
BTW I left a link to my SketchUp files back in 55, I think, after your comment on collaboration… I still haven’t succeeded in uploading changes from another computer though. (I tried again today) Also I can’t find the address of a PRT/dual mode animation I liked… I don’t remember if it was from you.. It was in water-color, to music, from like, the Swedish department of transportation or something. Demonstrated platooning, was lowered to the ground with cables, or elevators, had little wheels for dual-mode.. Does this ring a bell?

cmfseattle said...

yes, that's bubbles and beams - a convenient future.

i remember a letter in the local newspaper, from about 17 years ago. it had to do with what happens if you leave a little milk in an open carton. are we like mold? is it just our nature to use up resources until we die out?

i think the key words in your veracruz example are "a little dirt road." keep in mind what it will take to build an elevated guideway: can all of the raw materials, manufacturing, delivering and constructing be done by guideway? can it be done faster and at less expense?

i wholeheartedly agree that we should have incentives in building and tax codes for sustainable efficiency. (i also think that people should be encouraged to marry someone they love, but i digress).

They can always fly away from this rain and this cold

Dan said...

Dan The Blogger is back...

Thanks for the link, cmf… That video, quite honestly, shows ideas that are quite doable, technically speaking, in an unbiased way. (not pushing a particular system) I differ from the authors in that they seem to envision a carless world. In that world they would carry around wheels and batteries and steering in the PRT vehicle for the journey after the track runs out. That would make for a heavy PRT vehicle and a bad car. In my more modest vision the woman would be picked up at the station, or would get into her own vehicle and drive home. Here in Texas, people will still be using cars 50 years from now. It’s a big place…full of pick-ups and mud.

About Mold..It is true. Humans can take over like a cancer, killing the host. Some of us will work to ensure long term viability, but, alas, there certainly is, (wince, blush) some FUNGUS AMONG US!

What I really wanted to impart is that there are consequences to standards. There is some old video depicting the first crossing roads, with two model Ts crashing because neither would yield, as they hadn’t invented the stop sign yet. It raises a point. All stop, yield signs, red lights, train crossings etc., are symptoms of moving people and goods across a shared surface, the 2 dimensional ground. That paradigm eventually creates ecological disaster. Our hypothetical settlers have clairvoyance about this, and they can start with leaving the surface of the planet alone, knowing that path will eventually create a more sustainable world. I was presuming they had the benefit of hindsight, and plenty of resources.