When I was in early high school, I remember reading a book that was set in an alternate world in which vehicles slid along on tracks using a frictionless, perfect lubricant.
I thought it may have been a Discworld book, but I haven't been able to actually find what book it was. I'm not sure if it was a Discworld book or not.
edit: I think it was from a book that was kind of in the vein of
Red Dwarf or
Hitchiker's Guide or something similar. I liked those semi-humorous sci-fi fiction books at the time.
edit2: I think the cover also had some kind of cartoon people or animal-looking people on it, and may or may not have had a picture of one of the vehicles. Just kind of a carriage-style thing, maybe with sleds.