"Then it seems we could cut down air traffic considerably. NYC to Atalanta is only about 800 miles, if I could get there by train in four hours, a airplane would offer no time advantage.
If the difference in fuel efficiency is considerable, then maybe the US should consider building something like that?"
That is an interesting question, that I will have to go research.
I need to try to find credible numbers on the relative total-system energy required of hauling people via each method, and for hauling a ton of freight via each method.
I even wonder what the total cost of each system, say over 20yrs, would be.
(Share if you have already found such answers.)
Promptness is its own reward, if one lives by the clock instead of the sword.