Gravel roads are less expensive to build per mile, but the maintenance cost is actually "higher" when more people use them, so they tend to be replaced with pavement as populations grow in some area. That's really only true because cars use certain types of tires that run at relatively high pressure: 32 PSI for cars, 50's PSI for bigger trucks like an F-250. There are other vehicles with huge, low pressure tires that can drive around in woods or on wet sloppy fields without doing too much damage. The Russian made Sherp is one example (the tire pressure is less than 2 PSI):
From Here |
Typically, engineering or civil engineering problems reflect a narrow range of conditions and assumptions. The cost per mile calculation really does depend on the type of vehicles people drive. The type of vehicles people drive is an arbitrary historical accident. If everyone was driving Sherps instead of cars with tires that developed from bicycles and wagons, there would probably be many fewer miles of paved roads.
For most real world problems, there's no way to compute a true global maximum or minimum. This is one of the fundamental reasons central planning is such a bad idea. It's also why technocracy will fail miserably. It's also why civilizations come and go.
Coevolution is the model of nature. Everything happens all at once all the time.
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