They have a job to do. Yes, they could possibly pull in a short distance further on, but that would require the loaders to pull each bin (and return it) that much further and would delay them a bit each time. Maybe only an extra 30 seconds for each bin, but with a half dozen or more bins at each stop, that amounts to a couple of minutes. Multiply that by the number of stops on busy roads on the day’s run and you could easily be into adding several hours to their day. If you’ve ever done that job, you would understand why they do it. I just let them get on with what they have to do and write the couple of minutes’ delay off as an irrelevance (to me).