The bottom line here is making knowledge of the railroad widespread. There are lots of people who are potential riders who don't know the place exists. Of course, once they are there, they will need places to eat and sleep, which would be in short supply if the trains sold out every day. But we can worry about that when it seems ready to happen.
Some freelance writer needs to do a piece on the line and get it published in a big-time magazine like National Geographic. Also the A&E channel would be a candidate for some video propaganda; someone familiar with the process needs to get the ball rolling.