parking lots and even the old buildings around here are ground up and you can see big huge piles that are just reused on the same spot as a base.

I'm quite skeptical of planned cities. They tend to miss the boat on mixed-use development -- retail on the first floor, residential above. That's a very successful urban form, and one used along avenues in most old streetcar suburbs.

Intentionally non-gridiron, non-rectilinear streets also seem ill-advised. Non-straight streets seem to increase the amount of walking required and the amount of pavement needed.

Elegant design and concept. Almost utopian, really. But a few practical issues:

1. This would be highly unpleasant if the rail was above ground.
2. How do people get into and out of the city? Does another rail line run through the central hub?
3. How is residential and commercial divided?
4. How do people have access to the green space? Is it completely cordoned off for wildlife or can it be used for agriculture, recreation, etc?
5. Where are you going to build it? The Amazon? Siberia? Mars? Most development has already happened worldwide so the infrastructure is already there. Are you going to level existing cities in order to build it? At what cost to people and resources?
6. Air travel?
7. No personal vehicles of any sort?
8. Doesn't seem to allow much variety and options for homes and public spaces.

I think the plan is very practical in a post oil world but unfortunately we probably won't have the energy resources to rebuild our cities from scratch. I wrote an undergrad thesis on the same topic back in the early 80's and a few aspects are worth expounding on.

1. The size of the subcity is both a function of the practical distance to walk to public transportation, farmland and open space (considered by some to be 7 minutes in todays society) and the appropriate scale of political entities for a local democratic government (some say 7000 is the maximum). Its interesting to note that even when preindustrial New York City exceeded a million people most of its food was grown within a seven mile radius.

2. The plan only describes uses as housing but I would assume that the blocks are mixed use, with the lower level as commercial functions, particularly in the center. The hieght of the blocks is not discribed but I would assume about a 5 story maximum to maintain a human scale and efficiency. The thickness of a building is also similar to preindustrial blocks where lighting and ventilation where from natural, not mechanical means. In this case the street and squares become defined spaces. The space between buildings become as important and defined as the buildings themselves. I explored the idea of building blocks as solar envelopes, where the intent was not to have buildings shade one another for maximum solar gain. This results in a diamond pattern of pyramids but sacrificies the strong sence of defined space between buildings.

3. The shape of the blocks in this case is a result of organic (accretive) growth, similar to most preindustrial cities but with a underlying masterplan much like Amsterdam. In Amsterdam an efficient transportation system of canals for boat traffic radiated outward as the city grew. In this case a highly efficient, quiet and above grade rail network will provides transportation beyond walking. I suspect that air travel in twenty or thirty years will become extrodinarily expensive and large airliners will become dinosaurs. Large airports will become few and far apart. Trains are the future.

If you agree with James Kunstler, and I do, the US is probably screwed. The huge investment in the spralling suburban built enviroment will become the new ghetto. Will the lawn become a permaculture garden? Can we cover roofs with solar panels cost effectively? Will we get mass transit up and running at the scale necessary? Unfortunately the energy required to maintain this infrastrucure as it wares out will probably be not be viable. Can we recycle much of it? Maybe, maybe not. Calculations posted below indicate its probably not worth recycling asphalt into energy. Can you recycle a tract home and strip mall? Hummm?

I suspect the EROEI is roughly the same as tar sands: 1.5.

The EROEI of tar sands is much higher than that - this end-is-nigh article estimates 4:1, and this anti-tar-sands article estimates 6:1.

If you want to estimate from first principles, consider that official estimates by Canada's National Energy Board are that natural gas represents the main energy input to tar sands facilities, and that current methods use an average of 0.8Mcf of natural gas per barrel (p.16-17). At 1.05GJ/Mcf for natural gas and 6.1GJ/bbl of oil, we get a ratio of about 7.3:1.

Energy other than natural gas (e.g., diesel for mining equipment) will lower that ratio some, but not particularly moreso than in similar surface-mining operations. Accordingly, estimating from first principles supports an EROEI of about 6:1. Any estimate which is less than half of that is almost certainly due to wishful thinking; I've certainly never seen a shred of support for the claims of sub-2:1 EROEI, despite following the supporting links in, for example, this story. The available data simply doesn't support those claims.

Awesome; good for you. Out of curiosity, where?

>I was chatting with one of the county guys who said that there was a brief time last year where asphalt became more expensive than concrete<

In Post Carbon Cities: Planning for Energy and Climate Uncertainty I briefly discuss how recent spikes in asphalt prices are just one example of the many unexpected price increases we're already facing as we approach peak oil (or, as some prefer, "coast through currently undulating plateau of world oil production").

Those price spikes make for an interesting case study IMO because the effects they had on local street repair and construction activities --and the repercussions for local economies-- hold some lessons for how we might respond to peak oil in general.

The discussion in the book (p 25-26) is available as an excerpt at:
http://postcarboncities.net/pcc-excerpts

Daniel Lerch

Now now, LNG, that sounds like a silly dark medieval question along the line of th e current one in Iraq of "how many oil barrels can dance on the head of a hand grenade pin".

A great candidate for moderator intervention.

That's a ridiculous thing to say. How is anyone "necessary" for the world? It seems pretty clear to me that the world got along fine for a very long time before we started fucking things up, and that happened before we numbered 2.04 billion. How'd you come to such a precise number anyway?

The comment about Christians and some Jews being necessary is even more asinine. I hope you're joking, but even if that was a (sick) joke, it wasn't funny.

How many barrels of biodiesel can be extracted from 4 billion unneeded people?

I guess it would depend on what part of the world they were from. Though this might give you a rough idea.

http://www.upi.com/NewsTrack/Quirks/2006/12/06/liposuctioned_fat_could_b...

Venoy's firm in Miami is in negotiations with a hospital to give the company about 3,000 gallons of human fat a week from liposuction operations, which the company says is enough to produce about 2,600 gallons of biodiesel fuel.

A good lesson from history is the fate of the paved Roman roads, especially in Britan. Once the paved roads were no longer needed ( the Roman army had left) and could no longer be protected and maintained (the Roman army had left) the locals gradually used the pavement stone for other purposes. I don't think there was any plan to do so, it just evolved as the stone was an easy source for whatever purposes it was required. The transportation legacy was the well built, graded and drained road beds under the pavement. These still form the basis for many roads in Europe. This will be the same legacy for many of our roads and the main benefit will be the all weather road beds beneath the pavement although it is likely that a lot of that aggregate will be mined as well for local use. If we have specific "good" ideas for the use of asphalt we should leave a note for our grand kids and great grand kids. My personal favorite is that they will find a way to melt the asphalt out of the matrix and use it for waterproofing and maybe wood preservation. Short term there will likely be sufficient liquid fossil fuels for those who can afford it and I suspect we will be too busy with other problems.
As a digression, this network of well engineered road beds may make it less likely that the railway system will be rebuilt to its former glory in North America. Most railways here were developed before the road system and were successful in competition with water transport and the rough almost impassible old military and pioneer trails. It may be cheaper to carry freight on these roads rather than rebuild railways, even if the time of travel increases. The big problems with roads here will be the bridges and snow blockage in winter. But the Australian outback is a good model. Truck trains, probably moving a lot slower then the cowboyed ones I remember on the Alice - Darwin track, and eventually fords and overflows in the stream beds might replace expensive bridges. As with the wet in the Australian NT we may hve to become seasonal or at least weather sensitive. In the Canadian north we already do that with ice roads. This won't happen in my lifetime but I suspect that our decendents will walk a little less proud upon the land.

Jon WhoEverYouAre:

> every time you fill up at the pump or go shopping at the store, you just screwed another third world country <

There it is, the big ethical elephant in the room. We pull up to the pump, flip the lever on the voting machine, fill the tank in our tank, and pay the K-street lobbyists who do everything possible to keep oil addiction alive in Amerka. And then we pretend it is the fault of government, oil companies, car companies, and those bad people who have larger vehicles than our own. Or we pretend oil consumption is not a problem at all.

That's why you are more far more likely to see me pedaling on the road than pedal-to-the-metal inside a motorized exoskeleton. I don't say it to brag; it's what I can do with my life.

And before you reply with, "Well, it's just not practical for ___ to bike..." let me say this.

No, all of the people can't bicycle some of the time, and some of the people can't bicycle any of the time. But a hell of a lot more of us could bicycle a hell of a lot more than we do!!

Hans Noeldner

everything was reused or recycled until about the end of WWII when the whole consumption machine went into hyperdrive.

A German friend tells me that in her days when a pig was slaughtered, everything was used except the squeal. I don't see any reason why civilization can't get back to a more reasonable approach to the limits of the material world.

It may be "burning the furniture," but the better question is how much do we gain (or lose) overall by doing it. Less pavement means better rainwater capture for aquifers, reduced heat island effect, more room for agriculture or uncontrolled nature. It's yet another of those matters of "externalities." How do you reward (or punish) the indirect economic impacts of an action? Recovering fuel (or a resource in general; might be useful for plastics, but then that's a whole 'nother problem) is only a part of the equation.

I'm a newbie but this stuff is really cool so here goes...

Here a site that says that the amount of recycled asphaltic concrete in the US in 2005 was 41 million metric tons and about 7-10% of the mix is bitumen. About 80% of asphalt road materials is 'reused in some manner'.
So that would be something like 5000000 tons of bitumen.

http://www.tfhrc.gov/pubrds/05jan/02.htm

I think you get about .86 barrel of syncrude for a barrel of bitumen, and 7.33 barrels is a ton leaving 31000000 barrels of 'oil' if it were all used for fuel instead of road material.

I think virgin asphalt comes mainly from refinery coke which could be made into gasoline by gasification at the rate of 2 barrels per ton of bitumen.

I don't know how many highways there are in the USA but the government says that the National Highway System contains 35 million metric tons of asphalt.

http://pubs.usgs.gov/fs/2006/3127/2006-3127.pdf

Asphalt binder is applied as a mix of bitumen and naphtha and I've seen the figure of 35% is assumed to end up evaporated over time(US EPA).

Now there's a good answer.

But I'll continue with my half-assed one anyhow.

I reckon asphalt can be burned, and will be, as parking lots are reclaimed for ag in the future. I'd expect that being in the hot sun for years, old asphalt will have fewer volatiles left.

I've been in an asphalt parking lot - a relatively new one - to observe what happens when molten lava erupts in the middle of it... that is, a 7-meter lava cone with lava pouring out of it down onto the neat yellow lines. That's no small amount of heat, but aside from some minimal blackish smoke, there was no real burning of the asphalt. There was also a 2-foot chasm that opened in the parking lot which had orange flowing lava in it, and as I had to jump over it to get to the main firepit I can note that it was damn hot, but the asphalt was entirely unaffected.... well maybe slightly chewier but not inclined to burn. As it was night, any flames would have been apparent; the methane sprites were certainly popping up everywhere like blue fairies.

It's not that uncommon to have lava go over asphalt on the big isle, most often 'chain of craters road'. I take from my observations there that asphalt is not high on the list of burnable stuff, though I suppose if you chucked it into a furnace it would give up some heat calories. Bloody few volatiles left in the old stuff though I'd reckon.

Now, getting rid of parking lots for aesthetic reasons and to farm the land - there's where the energy benefit might be found. Perhaps in the future asphalt will be burned, but in those relatively depopulated times wood and weeds will probably still be the fuel of choice, and concrete will be mined for rebar... tough job there.

It's almost certainly not worth recovering asphalt from roads and processing it into synfuels, not only as due to it's low bitument content, but also from the fact that it would be very difficult to achieve the required "economy-of-scale" in the industrial plant. The cost of a grassroots plant only increases as the 2/3 power of its throughput. That's why you'll never see a "5,000 bpd upgrading plant" ever being planned and built. About 50,000 bpd appears to be the "minimum economic size" and hardly enough asphalt could be recovered from even a large city to accomplish this.

Since it could be reasonably argued that there is (will be) far more asphalted areas than is needed in a city, it does make sense to try and determine if it could be removed and what should be done with it. Also, by "not" doing it, you would leave people to their own divices as to its use, which could include "burning it to keep warm" which would result in an environmental catastrophe.

Having said that, you would first try to use what's there "in place" by building necessary infrastructure over it. Second, if it is deemed necessary to remove it, that it should be done in an orderly and useful fashion, rather than simply "ripping it up". Perhaps a (laser?) device could be devised to cut through it like a cake, and the pieces harvested as (20 lb?) bricks.

The bricks could be hauled out of town, perhaps on a narrow gauge rail build for that purpose, to build aqueducts or who knows what else. I think the bricks could be stacked on the perifery of a geodesic dome as supports, especially if this were to start from below grade (2-6 ft). Any other ideas as how these "bricks" could be used?

Thanks Brother for one of the most germane responses to my post thus far.

Indeed the EROEI for oil recovery from asphalt might be somewhat lower than that for tar sands, but consider the enormously different environmental impacts. Removing asphalt would restore aquifers, provide additional space for CO2-sequestering plant growth, expand habitat for wildlife, etc. And replacing asphalt pavement with buildings would be far, far better than greenfield development.

Anecdotally, I removed several hundred pounds of broken-up asphalt from an abandoned cowyard a few years ago (so I could shovel the soil, break up the hardpan below, and plant a garden.) I piled the material up in a burn-pile and it made a VERY hot fire which burned for a long time. And as it burned, copious amounts of melted tar flowed out of it.

Obviously it makes far more sense to recycle asphalt - IF we choose to maintain or increase the amount of pavement on Earth. But a major shift away from Happy Motoring could reverse this - and leave us with a major surplus of the stuff. If this happens, if richer sources of oil are exhausted, and to the extent that we still need modest amounts of oil, why not use it?

"no need for anyone to drive!

no need for a lot of things, suppose I want to drive though?

Some Answers to points made above...
Asphalt is 100% recyclable. And the statistic that 80% of it is, is quite impressive, as measured by tons, Asphalt is the most recycled material in the country. Even past the other petroleum product of plastic.
In NY, There is approximately 16,000,000 tons of Asphalt produced each year, usually about 4,000,000 for the state system. An increasing number of producers are recycling at a rate of 15%.
However, the bigger concerns come from the amount of fuel used to heat one ton of asphalt. Approximately 3 gallons. That's 48 million gallons or 1.1 million barrells of fuel equivilant per year. I guess in the scheme of things thats not a very large piece of the pie. But a lot of fuel for what you get. Then another 1/2 a gallon on average to transport, place and roll each ton.

Some better options for asphalt include recycling in place, this can be done cold utilizing some specialized equipment. To date, we cannot leave a recycled surface for traffic, but a thin (1" - 1.5") asphalt overlay is all that is required over 4" of recycled material. That is far better than ripping out and replacing 5"-5.5" with new stuff. The performance is excellent on moderate to low volume roads.

Permeable concrete... Yes, there is both permeable concrete and permeable asphalt, they are designed as a system to prevent runoff and are used primarily in parking lots. To date, no one has placed a permeable pavement on a roadway because high speed traffic would cause ravelling (the stones to come out of the surface).

In my experience, when roadways are milled and replaced, the millings torn from the road are always utilized in some fashion, as shoulder backup material (instead of using mined gravel), sent to the plant to be recycled, or sold to locals for driveways and parking lots. It is not the most desirable surface. Point is, there is never a concern of getting rid of milled asphalt.

The larger concern for the near term, is the supply of asphalt binder, as more of it is being diverted to the cokers and turned into transportation fuels, now causing enormous price spikes in asphalt.

Concrete does not last much longer than asphalt, generally both remain in place for about 50 years. Some going on more now. Each one is rehabilited at about 20 years, then again at 35 years. For Concrete, a rehab is either repairs or bury it with Asphalt. Asphalt is generally patched and buried with more asphalt. Or Patched, some milled off and a thicker section placed due to increased traffic.

rough, extemely rough. oil that weighs 0.136 ton/bbl would have an api gravity of 50.6 deg. however, i dunno what gravity is appropriate for your calculation because bitumen is not oil, certainly not in situ.

If your expectation is that Americans will continue to drive two and three ton exoskeltons everywhere we go - and then park for free in surface lots - then of course the prospects for harvesting energy from asphalt are DOA. My expectations are quite different, and, fool that I am, I hope we will make more enlightened arrangements for transportation proactively rather than waiting to be forced by scarcity and the bloody costs of maintaining Amerkan empire everywhere there are fossil fuels to be wrung from Earth's crust. Oddly enough, I have this quaint expectation that humans are capable of more than merely reacting to the price of motor fuel at the filling station. Enlightenment, perhaps.

Regarding our "need" for asphalt, this series of photos cuts to the chase:

http://www.unep.org/geo/geo4/media/graphics/Zoom/2.06.jpg

When we-the-people shift to spatially modest modes of travel, and when we cease to demand our own 10-foot by 20-foot patch of lifeless Earth at our every destination, a very different world becomes possible.

How much pavement is there in the United States? An area roughly equal to 2/3ds of the state of Ohio:

http://www.sciencenews.org/articles/20040904/bob8.asp

About half is streets, roads, and highways; the other is parking lots.

So if we make our streets and roads and highways narrower again (costs of maintaining four, six, eight lanes will become too high), get rid of many space-gobbling access roads, and pull up, say, half or more of our parking lots, then we have a lot of material to work with!

You're absolutely right. Apparently most people who have commented favorably on tearing up roads have never lived in a place like Afghanistan or don't even drive on gravel very often. Road infrastructure is an integral part of prosperity. No roads, no prosperity.

There is a valid reason for tearing up asphalt, however, when state gas tax revenue is so low that a system of paved roads can no longer be maintained. Minnesota is in this situation now. Governor Pawlenty has twice vetoed a gas tax increase and prefers borrowing money to repair roads. There isn't enough money from a gas tax that has not been raised since 1988 to maintain the existing road and bridge system.

North Dakota, which never had much money, relies primarily on gravel roads. Only about 12% of the road system is paved. The rest is gravel or dirt (and there is a huge difference between the two). Gravel roads are cheaper to build and maintain than pavement.

See, I didn't actually take this proposal seriously. I considered it more of a "modest proposal" type of thing. Kind of making a point but I don't think anyone expects people to rip out asphalt to make oil!!

Calcining limestone does not boil out water. Limestone is CaCO3. Heating releases CO2 which constitutes 44% of the limestone by mass. CaCO3+heat= CaCO+CO2. The CO2 released may be even older than that released from fossil fuel.

Good grief.

Another example of a little education being dangerous. And of a man convinced against his will is of the same opinion still.

You keep harping on bunkers. Bit silly.

Bunkers will be available long after gasoline is done. It's far cheaper to make; the worst crudes make lots of it; and the efficiency of moving products long distance by ship makes it possible for shipping to bid what it takes for the hydrocarbon assuming there is any international trade. Once cars are shifted to electricity, bunkers will be real easy to get as the remaining crude is left without the current suck of gasoline/diesel engines creating rapacious demand.

Please provide a link to a Spanish refinery that is only making diesel from crude oil. If it is only being fed vegetable oils, that makes some sense. RVO-->biodiesel is logical but it's not a refinery really. Raw crude oil has a big gasoline fraction which is a pig to polymerize into diesel sized molecules. No way anyone is wasting time doing that when gasoline export markets to the USA are so easy to tap.

European refineries have been focusing on diesel for decades (since the 80's spike). It's true their gasoline surplus heads to us, especially the US East Coast.

Propane/cooking gas will only disappear from the markets for 3rd world citizens if they can find an alternative. If there is no wood, they'll find a way to pay or do without cooked food which is unlikely. The price they can pay for a small bit of cooking fuel is enough to drive cars off their roads and probably ours too.

There are very few diesel generators out there. Typically only in places with very small demand such that coal or nuke just doesn't make sense. I already pay 41 cts/kwhr. It's cheap compared to washing clothes by hand. I'd cut way back on driving long before I gave up electricity.

Fuel oil electricity generation is dying off already. About the only place left in the US that uses it is FL. With the price of Nat gas so low, they'll expand capacity to FL. And then solar/wind/other will take over. And again, people will quickly learn to reduce transportation demand to keep the lights on if that's the economic trade off they have to make. Not much need to drive to a job if there is no electricity there for computers etc.

The only sensible point in your list is cheap imported gasoline will be harder and harder to come by.

If it gets cold enough in winter and people are cold, then it will get burnt - a great consolation for you city folk in northern climes...

As with roads, I think that the most volatile components will have long ago evaporated by the time a roof is ready for replacement.

Hell, lets burn the studs too. everybody build a sod house.........