Originally Posted by physioprof

Amtrak train tickets are priced dynamically like airline tickets using revenue-maximizing algorithms that are sensitive to expected/current bookings. This is in contrast to commuter railways that have static ticket prices (altho can be bifurcated into peak & off-peak). One aspect of dynamic pricing is that far-advance bookings are frequently offered only high prices, with the assumption that people booking far in advance have no time/date flexibility so will tolerate a high price to lock in what they need AND that if bookings are coming in low, there is plenty of time to lower prices later.