From what I can tell by looking at the illustrations in the book, the passenger cars of the Polar Express may be twice as long as the 24x train base that I used. I am pretty sure I can make a single passenger car with two bases, (48x total) end-to-end, and one set of wheels at each end. Are there practical limitations to the length of a single car? (I suppose it cannot be longer than the diameter of a half circle of track, but I would be nowhere near that.)
