I think we will see this when gasoline cars become a thing of the past and a heap of cancers reduce in occurrence and we put it down to reduced air pollution.
There are some parallels between the tobacco and auto/petro industry. Many north american cities had excellent tram systems, but they were torn out/abandoned for car roads under pressure from industry lobbyists in the 50-70s.
Some cities retained their tram lines (Portland, Toronto) from that era, but many did not (Chicago, Vancouver).