
One of the problems Amtrak is facing at the moment is a lack of rolling stock. The author notes that the California Zephyr was running full. It’s also running a shorter consist that it would have traditionally because of a lack of units. Increasing the length of the consist, assuming the engines can pull it, would reduce the emissions per seat. The ridership demand is there, the investment into Amtraks stock is, sadly, not.
Thanks for the informative reply and the references. Very interesting!