I'm familiar with those, and I have considered it. I could not fit that in the bus I would use (I can barely fit my backpack). The train is a dicey proposition; the car config I am on this morning barely has enough space for people plus a small-ish bag. I'd be taking up a second seat if I had a folding bike. Other consists have better luggage space, though even they are optimized for moving the maximum number of people possible.