We walk. Got stuff like vertibirds, and I saw a plane fly once. Never been inside either of those, though.

[She's not the first person to express confusion over the lack of cars. He's not surprised at this point.]

About two hundred years ago, every country with nuclear weapons launched them. Whole world changed. Guessing what the missiles didn't wipe out, the radiation did. Any cars that were on the roads when the bombs fell, they're still there.