I have done this many times especially during the great recession when UPS do not want to hire new drivers. Most of the time we would deliver to the sups home town about 30 miles from the center. I would drive the package car while he drove his personal car. Usually an 8 hour day so after deliveries I would do the pick ups and drive back while he went home for the day. He also bought lunch. One of the privileges of seniority.