“We’re now beyond 20 million miles of fully self-driving, like, really self driving,” Krafcik said in an interview at a Fortune Brainstorm Tech dinner in Las Vegas during the annual CES conference. “You need to have a lot of real world experience. There’s no way to avoid that. You must have it.”

The company started life in 2009 as a Google research project known as Chauffeur. It was renamed in 2016 and got permission to start its driverless service in the Phoenix area a year later. Waymo doesn’t disclose its revenue or profitability.

The company’s driverless cars, mainly Chrysler Pacificas outfitted with special hardware and software, are currently offering a ride hailing service in Phoenix. The service has about 1,500 monthly active users there. The company also uses its autnonous fleet to make deliveries in the Phoenix area and runs self-driving heavy trucks, Krafcik says.

Krafcik, who took the top jon at Waymo in 2015, is the former CEO of Hyundai Motor America. He also headed online car pricing startup TrueCar.

Asked when the Waymo services might expand beyond Phoenix, the CEO offered few specifics. “We’re considering moving that to other cities,” he said. Waymo also has extensive experience in California, but doesn’t yet have permission to charge for rides in that state.

Waymo’s rivals include self-driving projects from Uber, Apple, and Tesla, among others. California’s Department of Motor Vehicles reported that Waymo drove the most miles of any autonomous car company in 2018, at 1.3 million, followed by GM’s Cruise unit and startups Zoox and Nuro.

For more from the CES dinner, read “Why There Are So Many Scooters in Los Angeles” by Danielle Abril.

Fortune’s annual, invite-only Brainstorm Tech conference will take place from July 13 to 15, 2020 in Aspen. For more information, click here.