“We can only drive in places that we have already built a map,” said Andrew Chatham, the software engineer who heads mapping efforts at Waymo, the self-driving technology company.

Waymo — its name drawn from the slogan “WAY forward in MObile” — operates a driverless taxi service in a Phoenix suburb, and so far, so good. Then again, it’s Phoenix, where sunshine prevails and roadways are relatively benign. “A critical part of working as well as we do is being selective in what we attempt to drive,” Mr. Chatham acknowledged to Retro Report. “We are not driving in the dense traffic of Mumbai, where you have really hairy traffic conditions. We are not yet driving in the worst blizzard that you can imagine.”

While the video focuses on technological challenges, there are societal concerns as well. For one thing, several million Americans earn a living behind the wheel, driving trucks, delivery vans, taxis, app-based cars, school buses and other vehicles. In a truly automated universe, they would have to find new ways to feed themselves and their families. Ancillary businesses from auto-repair shops to gas stations would probably be affected, too, and not necessarily for the better.