Assembly lines can replace a lot of that. My company has several miles to move parts. Get the part off the truck (Just in time - nothing is on the truck if we don't need it that day), attach it do the line, 30 minutes later (after going all over the factory) the guys detach it and put it in the cnc laser. Then back on that line to go to the bending operations, then off to welding, then paint, then to final assembly. Parts can be on and off a dozen times in a process that takes days.

We don't have a line like a traditional car factory final assembly because we need to be more flexible, but there are conveyors going all over. (interestingly final assembly is still pushed down the line by hand)