When I was a cover driver some of the areas still had RR and RD numbers (RR=Rural Route and RD=Rural Delivery), which could be a nightmare. Thank goodness for the 911 conversion as all of the areas in my center are now numbered for 911. You would have an address such as RD 2, Box 360, and there would be 3 or 4 mailboxes on the side of the road with driveways branching off from there.
We still have some areas that the 911 addies have not gone into effect fully so we end up withe a mix. Most of the RR areas have card files that help alot(if they are done well). One are I cover is for two different towns, there are three boxes of cards. The driver that just left this area had done a terrific job of adding the 911 to the cards already made up, so you had it covered in two directions. There is one RR14 Box *** that is 12 miles from the front door, but once you've been there you will NEVER forget it.
While the driver wants to enjoy his day off, he does not want to come back to a bunch of lookups and send agains so check with him to see if it is OK to call him during the day.
I will only call the driver IF he/she volunteers the OK. I never ask them if it's OK to call.