If there are economies of scale in delivery, and certainly if mail recipients do not want multiple carriers accessing their mail boxes, it would be possible to define routes, along with their expected workload, and auction them off to the lowest bidder.
It would be possible to define routes, along with their expected workload if there are economies of scale in delivery.
A man with a black t-shirt on with adidas written across the front and a woman with a white t-shirt on and a silver bangle on her left wrist sitting next to their bike on the ground in the park eating ice cream while people enjoy themselves all around them