“We are inventing a lot as we go. No one’s ever done this before,” he said at the Wall Street Journal’s D.LIVE conference in Laguna Beach, Calif., referring to the large-scale deployment of autonomous vehicles.

That kind of scale matters, Ammann said, because every year in U.S. 40,000 people killed in road accidents. Globally that’s 1.2 million people. And 95% of those are caused by human error, regulators say.

“If we can get to a point where we can make a significant impact on the human error part,” Ammann said. “That promise of what the technology can do and what benefit it will bring will help [explain] why the world will be a better place with this technology.”

And what about General Motors? The American automaking giant is in the business of selling cars. How does that model work when humans no longer drive them? (GM spent more than $1 billion on Cruise Automation, a startup that makes self-driving car technology, last year.) And if ride-hailing and car-sharing services like Uber and Lyft cut into the need for a privately owned vehicle?

Ammann said he isn’t worried. Rather, it’s quite the opposite. “Every year in the United States in total there are about 3 trillion vehicle miles,” he said. “Ride-sharing accounts for one-tenth of 1% of rides traveled. We’re still at the early stages…it’s very early days.”

It will be a long transition, he said. “Significant growth from a very small base,” he acknowledged. But a “big opportunity” nonetheless. By making transportation safer and lower cost, GM believes it can actually grow total vehicle miles traveled or total passenger miles traveled.

Said Ammann: “We see the future as being significantly autonomous.”