Devel-new, etc. City roads, or otherwise unowned roads, when worn out, will be mothballed, and not replaced; and it is not always readily apparent when this happens, because vehicles stuck on the worn out road will not report being stuck (only vehicles held at a stop and unable to reach the next will report no route).
There is code intended to renew unowned ways inside city borders. Unowned ways outside city borders are considered to be abandoned with nobody to look after them, and are therefore allowed to degrade. Have you found instances of degrading of unowned roads occurring inside cities?