So my answers are best guess on what I witnessed. I don't think its as easy as just showing up and driving off. All of the things sorted at the Plant level still would need to be broken down and sorted even more once it got to the local post offices. I can't say for certain who was responsible for sorting it, but I would imagine the drivers do a play a role in it before starting their daily route. There is still too much sorting that needs to be done at the street/neighborhood level. I really should know more as I am also the son of a retired Postal Exec, LoL. But that's my best guess.

As for work hours I can't speak on that from a carrier perspective. I know that clerks usually always wanted the overtime. We had goals and objectives we had to meet. If there was more mail than anticipated, we could work extra hours. Based on the carriers I talked to a lot depends on your route, and your own level of efficiency. I think they get better at it overtime. I don't know the intimate details. Its hard to explain but there are multiple unions in the post office for each job responsibility, so people were a bit sensitive when asked about their specific duties.