Paine Field in Everett, existing one that Boeing uses for new aircraft. Public uproar when Horizon tried to add 2 flights per day.
San Diego is a good example, that parking structure was permitted (and approved by the FAA) for another level. The only reason there isnt, is that the workers refused after getting scared to death building what they did.
Heathrow and Gatwick, extra runways hasnt quite set in yet with the public
These crazy scenarios with simulataneous parallel ops, reduced sep appraoch, time based sep, and other capacity strategies are here to stay, and are only going to get tighter until the 99.9% is crossed.