New York to San Francisco
...is the perfect route for a proper high speed or maglev train service.
The South Korean government is planning, when their re-unification eventually occurs, a line from Seoul to Moscow. I met the chap planning it.
on Jun 4, 1876 the "Transcontinental express" did NY to SF in 83 hours, coal fired and hand stoked. Today it takes over 140. Doesn't sound like progress to me. The rail distance is something like 3,400 miles. Were that all French TGV standard it would take around 17 hours. The technology to get that below 10 hours is either known or imminent. For heavens sake, the old British Rail 225 sets from the late 1980s could do it in 22 hours, at least a few times. Virgin's Pendolinos could do it in 27, although It might take longer as I think they might have to stop for a lube break at some point!
By the time fossil fuels expire we might be very pleased to take 24 hours for a journey that would take 4 to 6 months on foot.
I'll get me coat. It probably still has a 1968 combined volume in the pocket.