Behind all this lurks the specter of the self-driving car--the emblem of a paradise in which all transportation, everywhere, is replaced by software that regulates, with serene efficiency, the motion of an entire civilization.. This is the vision that animates every regulatory collapse, every public-transportation failure, every taxi driver's lost livelihood. For the consumer, the system is already automated: you press a button, a car shows up, you emerge at your destination. It is, in the jargon of the Valley, "frictionless".

Eventually, they say, it will all be worth it. It doesn't seem to matter that these advances are far in the future or may never take place. Meanwhile, an actually existing concept--affordable mass transit--is being lost.