I was looking at a book on graphical wayfinding for one of my classes, and stumbled upon a couple of chapters devoted to the standard Amtrak informational signage found in most NEC stations. If your local library has this book, it would be worth picking up just to see the design process. Apparently the author's design firm was engaged by Amtrak to develop the signs a few years ago.
http://search.barnesandnoble.com/Signage-a...e/9780471748915
http://search.barnesandnoble.com/Signage-a...e/9780471748915