[shiroiuma]

Acela is indeed fast for a short stretch. But the average speed is terrible, so it's only "HSR" on a technicality. It could be serious HSR if they had control and/or ownership of the entire route and made it as good as that short section where they can hit that peak speed.

Acela is like a Formula 1 car that gets to do one quick lap on a nice racetrack, then has to take another course through bumper-to-bumper traffic for the rest of the race.

[TylerE]

You’re overstating it. The rest of the route is, except for a couple of areas around stations, a 125 limit, which is still basically double what Amtrak averages anywhere else.