Asphalt and concrete are substances where a lot of heavy metals and other materials being hazardous to one's health are being "deposited". But what to do with them when concrete and asphalt have passed their life time or when they are substituted by better materials or even obsolete, e.g. due to different transportation systems no longer requiring streets? I read this question about Concrete vs Asphalt, but it aims to a different doubt trying to evaluate one against the other. My question is about long term effects.
Asphalt is already recycled extensively. Locally when repaving streets, they chip up 2-3 inches of the existing road bed, heat it, add a bit more asphalt to the mix, and repave the street.
Perhaps this is actually reuse.
Where shipping is expensive concrete is broken up, and used as aggregate to make new concrete. You don't have to ship very far before the cost favours this re-use.
(I am skeptical about roads be replaced any time soon. Even if mass transit becomes good enough that main arteries vanish in cities, I think you will need the equivalent of roads in place to build the transit systems.)