[Shitty-kitty]

The advatange they have is that all 4 of their major metropolitan areas are in a straight line across flat land. The enemy of high-speed is any diviations from flat and straigh. On he accela top speed can be maintained less then 40% of the trip.

[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.

[kalleboo]

Japan isn't that flat. The Tokaido Shinkansen has 70km of tunnels (12% of the route), and for the new maglev Shinkansen, they're boring 250 km of tunnels (90% of the route!)