I am not an Civil Engineer [but instead a fearful fast-crash doomer], so the following essay may have merit, or be totally assinine and unpractical.  Most experts discounted my earlier idea for using billions of steelies for Petawatt energy storage and generation.  Thus, I will leave it up to those with greater expertise to determine the validity and cost-effectiveness of my next set of wild ideas.  Perhaps it will stimulate in some clever inventor's mind an even better solution.

I don't think any TODers dispute the fact of future food relocalization as the primary source of our postPeak nutrition.  I also believe that potable water will be an extremely valuable resource, and waste from leaks will be totally unacceptable.  The first two articles in this EnergyBulletin link are excellent examples, and most experts think Global Warming will make H2O even more precious in the future.  Additionally, from the response generated from my prior postings: I detected a huge social reluctance to giving up flush toilets for humanure recycling.  Thus, I present for your Cornucopian Consideration:

Energetic Optimization by Combo Fast-tracking our postPeak Spiderwebs!

I am all in favor of TODer AlanfromBigEasy's proposals, but RRs and mass-transit will have limited reach into the permaculture countryside--the heavy steel wheel on a thick rail spiderweb with electrification just will not go everywhere desired.  The tonnage moved generates very high PSI load factors on the rails.

Yet many TODers have posted on how most roads will crumble to postPeak dust from lack of energy, heavy equipment, asphalt, and concrete to do meaningful repairs.  Recall my earlier posting where 4 Mexicans died in a shootout over filling a pothole.  So, using the precautionary principle: we should assume most roads will return to dirt, and mud when it rains.  This can be very abrasive and jarring to future PHEV's electro-mechanical innards, and bicycling in the mud is very inefficient.  

Additionally, it occurred to me that rubber tires will be extremely expensive postPeak, or even unobtainable.  Recall my much earlier posting on how bicycles were among the leading inflationary items in Zimbabwe.  I bet bicycle tires are very expensive there, too.  Most of us are familiar with flats from thorns, and the human energy input required to overcome the rolling resistance of rubber tires, too.  It won't be any easier if your bicycle is laden-down with 100lbs of permaculture produce that you are trying to get back to the urban market either.

Thus, we should expect our milgov, if they are on the ball, to require a small factory in every US town to relocalize bicycle tire manufacturing until even petrol for this is no longer possible.  Currently, I believe nearly all bicycle tires are made overseas, but postPeak China will probably reclassify this industry as a military-strategic asset, thus shutting us off from resupply.   Again, the precautionary principle should impell us to consider a better solution.  Keep reading TODers: I will shortly tie these thoughts all together!

Additionally, if we are smart: we must consider the mind-boggling amounts of the future energy and materials required when we start to replace the millions of miles of our underground utilities' infrastructure spiderweb.  For example, here in my neighborhood of the Asphalt Wonderland: water, sewage, electric, natgas, cable, and phone service is all located underground.

When energy, pipeline materials, and water was cheap, this was a logical decision.  Using heavy equipment fueled by cheap gas & diesel: it was EXTREMELY EASY for trenchers, backhoes, bulldozers, and dumptrucks to move billions of tons of dirt.  Big, long haul truckers and lifting cranes had no problem loading and delivering millions of tons of pipeline materials all across the country.  Energy-intensive concrete and asphalt, no problem when you have giant shovels, rock-crushing machines, vibratory-screen rock & sand sorters, and concrete mixers. But that was then [the front side of the Hubbert upslope].

What do we do now that energy, pipeline materials, and water will be very expensive?  Never forget that a barrel of crude = 25,000 hard physical man-hours of labor.  Can we find an easy way to quickly and easily maintain any pipeline and likewise detect a wasteful leak?

Can we economically afford to dedicate that many people to hand-digging up, replacing our aging infrastructure spiderwebs, then reshoveling the dirt back, when I think most of us will already be engaged in daily permaculture labor?  Can we even find enough people willing to do this back-breaking work, or will it take slaves @ gunpoint?  I think most of us would prefer weeding a tomato patch vs wielding a pick & shovel all day!  Can we find a partial solution to dirt roads as we remake our towns into walkable & mass-transit dense clusters?  Can we find a way to ride bicycles and drive PHEVs without postPeak rubber tires?

Perhaps we can, if my wild-ass ideas that tie these aforementioned problems all together has any engineering practicality! Keep reading please!

Just as a railroad has a standard gauge--I propose we move much of our replacement pipelines above ground as required, and establish special, reinforced gauges that are conducive to both the material transported within and the bikes or PHEVs on steel wheels that can ride atop them.

This eliminates the postPeak: hand-digging; allows easy leak-detection of water, gas, sewage, etc; simplifies maintainence & repairs & further extensions; and many or most crumbling roads can be converted to these combo pipeline-railbeds outside of the remade mass-transit towns and cities to provide the tracks for bicycles and PHEVs.

Please use your vivid imaginations for a few minutes and picture, in its spiderweb totality, what enormous networks lie underground in your location.  Most will 'mentally unearth' parallel tracks of freshwater and sewage lines that intersect at the paved intersections where the manhole covers hide their underground presence.  Move those pipes aboveground 'for real', make them extra thick & strong, then weld a thin rail on top of each as a track for bicycle or PHEVs.

Thus a postPeak town would be largely laid out in a linear, or maybe x-y axis fashion, with the high trackbed PSI gauge RRs & mass-trans on this critical 'spine'.  Then the next gauge of reduced PSI PHEV track-pipes branching out as the 'ribs' to the innermost permaculture boundaries.  The PHEVs could be very light because no suspension system is needed for handling potholes [trackbed is very smooth], and minimal rolling resistance means a smaller motor is needed.  Then, the field-workers make the next transition to the smaller, final parallel Bike track-pipes that continue outward into the permaculture and ranching hinterlands as far as economically feasible.

Depending upon the optimum town layout configuration, but still using a standardized gauge: the track-pipes could be all outgoing sewer pipes headed to the sewage treatment plant, leaching fields and/or composting areas, but the workers would be actually riding the spiderweb just as a real spider does in nature.  IMO, this is much more efficient than the workers commuting in a vehicle over the same route of the pipeline just underneath them-- you have tremendously reduced most of required dual infrastructure investment and maintenance!

Workers headed to a refinery, brewery, or biofuel plant might be riding atop track-pipes containing the raw inputs [water, or biomass-slurry, or outgoing track-pipes of ethanol, or biodiesel, even beer?.  )  But again, the workers would be actually riding the spiderweb just as a real spider does in nature.

If appropriate health and safety standards can be met: workers could even commute atop track-pipes carrying electricity from windmills, thermal & standard PV gen plants, nuke plants, and so on.  =The main point is if  standardized gauges can be set, it doesn't matter what is being transferred in the pipes.  Obviously, care must be taken so that water and sewage pipes are not joined together--paint the pipes different colors!

Even if economic conditions shift whereby eventually nothing is transported in a section of track-pipe, but the rider route is still deemed essential-- this is still cheaper, and more energy efficient than trying to build a postPeak road.

Okay TODers, I hope I tickled your synapses.  I welcome any critiques, but most of all: I hope someone has an even better multi-networked infrastructure with a lower cost-basis.  But remember: clever spiders use their single webs for food-gathering and storage, water-collection by dewdrops, and area transport.

Maybe we should become Spiderwomen & Spidermen too!

Bob Shaw in Phx,Az  Are Humans Smarter than Yeast?