The car industry is on the verge of its biggest transformation in more than a century, with a fleet of fully self-driving cars coming “sooner than you think,” according to General Motors President Dan Ammann.

In an interview with BuzzFeed News, Ammann seemed fully on board with the technology industry’s most ambitious ideas about the future of transportation: the transition to autonomous cars, owned not by individual drivers but by operators of networks of on-demand taxis.

"It’s not often that in a business as big as the business we’re in and a company as big as ours, that you stand at a point where the whole foundation of how your business has operated for the last 100 years is up for discussion,” he said.

Ammann, who has been the number two executive at GM for just over two years, said the rise of smartphones has changed the economics of driving in ways far beyond just enabling ride-hailing apps. Our phones have become so valuable to us that being forced to look away from them has created “a significant opportunity cost for the time you spend in the car,” he said. “The time you spend driving is the time you spend not doing something else.”

Self-driving cars will also “fundamentally enable massive scale adoption of ride-share,” he said — in large part by removing the need for paid drivers. Ammann has been a board member of Lyft since GM invested half a billion dollars in the ride-hailing company this January.

“The vast majority of the cost of a ride-share ride, of a Lyft today, is the driver,” he said. “If you can take the driver out of the equation, the cost of that comes down dramatically.”

While Lyft is still definitely number two to Uber, it has been gaining share in some markets, and “once you introduce the driverless technology, the whole second phase begins," Ammann said. Uber is as aware of this as anyone and has been furiously hiring engineers specializing in robotics and artificial intelligence. Lyft, for its part, has said that it will have autonomous vehicles in 10 years.