Originally Posted by
fairviewroad
Amtrak doesn't do this, however. Amtrak does charge different prices based on remaining availability (i.e. the "bucket" system) but this is different than arbitrarily charging different prices based on time remaining until departure, as you suggest. A train with 20 available seats is a different product, arguably, than a train with 100 available seats.
On Acela, I really think "time till departure" is part of the pricing formula, especially if it is within a few hours. Every time I have to switch trains, it's either the same fare, or I have to pay a difference. Not one time did I get a partial credit good for future travel.