The concept of self-driving cars is beyond the idea stage...they’re already being tested on the streets near Google’s campus in California and elsewhere. And transportation tech companies like Uber and Tesla are laying the groundwork for a future where people travel around cities, and perhaps eventually the nation, in autonomous vehicles. So, what’s that going to be like? And what could it mean for the way we work, play, and live? Gabe Klein weighs in. He's the former head of the Chicago Department of Transportation and author of the new book Start-up City, which in part looks at how public policy is dealing with the advent of self-driving cars.