we need an ethos of sacrifice for the greater good, or there will be no future, or at least not a good one.

God, I'd settle for an ethos of sufficiency rather than excess.  Enjoying what you have rather gluttony.  The good news (I think) is we are soo wasteful and gluttonous that if we just take was we need it would make a big difference without ever needing to get to sacrifice.  

Of cource this doesn't apply to the poor countries which are already in states of deprivation.  

I-70 through the mountains of Colorado is approaching gridlock even on non ski weekdays. Something has to give, but it does not seem feasible to expand the highway through the mountains.   The economies of all those mountain towns, mostly built up since the introduction of the interstate, are completely dependent upon that highway.  In this case, part of the solution has to be interstate specific. If the gas tax is to be relied upon, there is  no particular disincentive to get out of your car if your destination is say, Vail, coming from Denver.  Since long term solutions like rail won't be available for at least 20 years, wide scale bus transit must occur in order to prevent 24/7, 365 days per year gridlock. Just providing buses, even if subsidized, won't get the job done. Ergo, provide heavily subsidized buses, park and rides,  and impose heavy tolls to get people out of their automobiles.  There will still remain the problem of truck traffic which will have to wait for diversion to rail.