I mostly ride on back roads and side-streets, my city banned billboards and is very small and close enough to the woods to not feel like one. But I get what you mean.
This makes sense. City I am coming from haven't done this and the billboard/advertising agency is very close with the city mayor, meaning, all the (main) streets are littered with advertising. Everytime I come home for holidays (from a large EU city, mind you), I am overblown by just how many billboards are around. Crazy.