I agree with others on the thread that "maintenance or innovation" is a false dichotomy. In particular, I think we need innovative maintenance. For e.g., this article about new ways to fix potholes: https://www.economist.com/news/science-and-technology/217003...
interesting article and comments. one commenter points out that roads break down because of overloading (heavy trucks). another points out that, in colder countries, ice is a major problem for roads.