Driving and delivery versus loading

I loved this piece in the current Fortune magazine about the training of UPS drivers: "The making of a UPS driver," 11/7/07, byline Nadira A. Hira. Everything in it is fascinating, although I would have loved to know more, much more, about how the trucks are loaded and what governs package placement, other than, probably, route-delivery order. UPS has a long history and is known as a far better employer than its modern-day chief rival, which shall here go unnamed.