Currently, an envelope mailed in Williston, ND travels to Bismarck to be sorted and returned to it's destination in Williston. A payment on a water bill was mailed there, and traveled over 500 miles to go half a block away (and took 5 business days to get there). The person who mailed it, now uses the drop box on the Water Department wall, and cuts the USPS out of the equation entirely.
There is talk of moving that sorting facility to Fargo, which would add about 300 more miles to that round trip.
When I first arrived in this area in '79, they had two slots on the wall at the P.O., one for outgoing 'in town mail' and one for 'out of town mail'. Seems returning to that might be a thought.