I have to wonder how much of the city overall is used for cars -- roads, highways, and the "buffer" land surrounding them (like the land in and around a highway

I have to wonder how much of the city overall is used for cars -- roads, highways, and the "buffer" land surrounding them (like the land in and around a highway interchange); parking lots and their access streets; businesses dedicated to servicing cars, like gas stations... It's probably a lot.