Probably the easiest thing the US could do to reduce oil usage would be to find a way to electrify freight railroad mainlines. There are only about 10,000 miles of mainline left, but they haul a staggering amount of freight over those mainlines. Electrification would allow the US to use plentiful coal or nuclear power to move stuff.
The Department of Defense has identified approximately 52,000 critical miles of trackway in the continental US. Electrification via nuclear ought to be a huge priority in this country (despite what you or I feel may feel about nukes) on those 10k of mainlines (and serious upgrades for the rest).
A site I keep bookmarked has, here, a very good photo essay of
The Alameda Corridor through Los Angeles. I recommend the accompanying article[s] and look for Youtube videos. Heavy rail takes a long, long time to do correctly. But the savings are huge!!
Very good thread. Trains are always fascinating. Or, as one man put it: Streetcars are the sign of civilization. (I should like to see the return of interurban cars. Now
there's a potential for streamlining single & double cars to link minor towns to major metro areas!
.