[aposm]

All the major metro areas on the Acela corridor are also on a straight line, on significantly flatter land than Japan. Notice how the Acela never spends 10+ minute periods in long, deep tunnels under mountain ranges. The Acela primarily spends most of the trip going below 100 mph because it is operating on 100+ year old infrastructure that has only ever been upgraded piecemeal as it starts to fail.

[technothrasher]

It's always feels funny to me when taking the Acela between Boston and NYC that you go screaming along at 150mph... for a small portion of track in Rhode Island. The rest of the time you're going much slower. It's almost like, why even bother for that small section?

The Shinkansen was a very different experience when I took it.