I can't find the post but there was a graph going around about the cost of transport of MAN ON A BICYCLE so I went digging in the sources and found this older article1. The machines probably need to be updated though, since this is from 1975; I would guess that cars are much more efficient nowadays.
(It would be interesting to also average the cost of mass transport over the number of people it carries, but which costs do you include for a operating whole rail system?)
-
Tucker, Vance A. “The Energetic Cost of Moving About: Walking and Running Are Extremely Inefficient Forms of Locomotion. Much Greater Efficiency Is Achieved by Birds, Fish—and Bicyclists.” American Scientist, vol. 63, no. 4, 1975, pp. 413–19. http://www.jstor.org/stable/27845576.