I've been commuting by car between Philadelphia and Baltimore about one to two times a week (usually around weekends) and wanted to get thoughts on the best Amtrak options for this route.

I've rode Amtrak a handful of times over the years but my primary flyertalk experience is with United flights.

Anyway, what would be the best/cheapest way to make this trip on Amtrak? Are there monthly passes or frequent rider programs that would provide much benefit? It looks like a lot of the trains running this route (northeast regional) have restrictions in terms of bulk ride passes, etc. so I wanted to get some advice.

Thanks in advance!