not intentional and I suspect that is why some of the older scenario reports mention paved roads in strange spots usually involving buildings piled on buildings.
EDIT
I made an example that maybe can be debugged. Since it's being reported in scenarios that go right back to the beginning it may have been there since day 1
It will go away when you add clear terrain to the hex that reports it but if it's the building registration hex you will lose the building. In this case, avoid piling buildings on other buildings but if you feel you have to then " tidy up" around it when you are done so yes it's "a bug" but it only seems to appear when buildings are piled together and the solution is "don't do that" but if you have to check the perimeter for reported road and clear it away with page 1 clear terrain