When I was in the Military,(80's) I used to have to cross the runway(many of times)to get to the "hot spot"(as it was called)…It was mandatory that I used the phone to call the tower and ask permission to cross both runways mid-field…they would respond with at yes it's clear or tell me to wait…and I would have to wait on the line to get the permission…then proceed across the runways and I would have to do the same to come back…I pretty sure, that the aircraft would have to ask permission to cross thru "Flight paths" to do the same if not go around the runway or flight paths