Even Shared Autonomous Vehicles Could Spell Traffic Disaster

A city full of self-driving cars might not be a city you’d want to live in. This is the nightmare vision of some transportation experts, who fear what a swarm of privately owned robot cars could do to already-congested urban roads and highways. Imagine roads jammed with “zero occupancy vehicles” circling to pick up their owners or run simple errands. The rise in overall vehicle miles-traveled (VMT) would be dizzying.

So, the logic goes, the cars must be shared: Think driver-less versions of the Ubers and Lyfts we already know and love/hate. That’s the scenario most carmakers and cities are assuming as autonomous testing grounds open up across the country, and the very first robo-shuttles lurch their way across university campuses and down public streets. (Tesla’s Elon Musk is banking on a different future, one in which there’s an ongoing role for privately owned vehicles like the kind he’s selling.)