Honestly, I have barely a clue to what I’m doing right now. 
(though I am slowly learning!)
The bulk of that query came from @zelonewolf 
and the modification that excludes nodes outside of the border came from mmd.
I’m unfamiliar with the permissive and destination tags, but now I’m learning about the different types of access!
We’re getting off topic here, so I decided to open Overpass Street Query for discussions on this query. 