The driver for the small town where my office is hauls a trailer up to the truckstop by the interstate every morning, drops it out back, then does his deliveries. A crew of other UPS employees shows up in their private vehicles and delivers everything out of the trailer, then he grabs it on his way back to the depot at the end of the day. Drive past any UPS depot this time of year and you'll see a fleet of U-Haul/Ryder/Penske rental trucks. Their normally part-time box-kickers go full time around the holidays and make deliveries, and they bring in temps to load the trucks.