Now that's impressive!!
Funny thing is, here in Ireland there are no postcodes anywhere and no road names in the countryside either.
A typical address here could be
John Smith
Ballymahon
Co Longford.
Or if the postie is lucky there will be a smaller townland so he might get
John Smith
Sciona
Ballmahon
Co Longford.
Ballymahon would have a population of about 3000 and could have 50 or more townlands over an area of 10 to 100 square miles.
When a new postman starts, he goes round with the old one for a few days to learn where everyone and everything is (addresses and maps and reality are often different, some people have 2 addresses because parish maps and official maps often don't overlap) and who to ask if they can't find someone.
When someone new moves in, the postman has to ask people he meets until he finds the house they have moved into!!
The funny thing is....... it works.
I send a lot of letters in the post for work, probably a 1000 a year, 99% get there the next day, I could count on one hand whats got lost over 10+ years and they open it and send it back to you if they really can't find the recipient (the postmaster/mistress in the local post office does this).
It might be a bit laughably old fashioned, but its a great system.