Used to do a route for many years where I worked the dock sort. The route that loaded my truck was 4x10, every package was in the right place every day the main guy worked, if he didn't know an address, he would leave it on my dock shelf. I'd get to my truck, scan 200 or so packages in a few minutes, and be out the door. Problem was, when the fifth wheel or swings loaded it, it was an absolute CF. Eventually I just told the fifth and swings to just stack it all behind the truck and on the tail, was easier for me that way.