Here's the video by Ross Ching, Running On Empty, that Bill Barol referred to here a couple weeks ago. I think it's a great bit of provocative future fiction showing the vast topologies of the Los Angeles roadway infrastructure absolutely free of automotive traffic. Perhaps a sudden, massive lifestyle change has ended car use. Or a Peak Oil soft landing, or personal teleportation devices have gone mainstream, or the Rapture came and somebody lost the list of sinners and just decided to take everyone... I like to imagine this vision rolled forward 20 years when vegetation has overtaken all the useless hardscaping, no doubt matched by some Jumanji-type unleashing of large fauna across the sprawl.