أنشئ حسابًا أو سجّل الدخول للانضمام إلى مجتمعك المهني.
It depends on numerous things.
I guess that in poor countries it's better that it's public, under the condition that people that are managing it, are not corrupt and incompetent.
In richer countries i guess it's better that is in private ownership, under the condition that there are law regulations, that sets the minimum for managing and maintance of roads.
