Seat reservations aren't guaranteed though and some Train Operating Companies (TOCs) don't offer seat reservations at all. Even without a seat reservation your tickets are still valid, and you can sit in any vacant unreserved seat. Sit in any vacant unreserved seat except First Class.
If overcrowding becomes intense, first class can be “declassified”, i.e. opened up to all passengers, regardless of their tickets. But there is no automatic right to occupy first class. Ad hoc declassification typically happens after other trains have been cancelled or seriously delayed.
Domestic Airline PoliciesWhile we do not permit customers to switch seats between classes, due to the fairness and safety for other customers, we do recognize that unique situations arise and we encourage any customer needing special assistance to speak with a flight attendant.
More and more airlines have been adopting upgrade auctions for otherwise-unsold premium economy, business, and first class seats.” For airlines, Keyes says the rationale is simple: upgrade auctions generate significantly more revenue for airlines than handing out upgrades for free.
Arriving at the StationPlan to arrive at the station at least 30 minutes before your train is scheduled to depart (Auto Train passengers should arrive at the station at least two hours prior to departure).
The most comfortable seat is the one all the way up front in the locomotive. Yes, some of Amtrak's trains are Superliners, and they do indeed have two levels. However, only the upper levels connect between the cars. A reserved seat is not an assigned seat.