Self-Driving Cars Keep Tapping the Brakes

In December, Waymo LLC, the leading driverless-car company, brought out the world’s first commercial robo-taxi service. But for now, the service is only available to about 400 test families in suburban Phoenix, and each of its converted Chrysler minivans still has a person at the wheel in case anything goes awry.

“It’s a pretty glaring indication that we’re not there yet,” says Matthew Johnson-Roberson, co-director of the University of Michigan’s Ford Center for Autonomous Vehicles, who’s working with automakers to develop robot rides. Waymo, owned by Google parent Alphabet Inc. and recently valued at $250 billion by Jefferies Research LLC, declined to comment. In a blog post, Chief Executive Officer John Krafcik said the human safety drivers were at work in Arizona to make riders feel more comfortable.