It is the latest real-world test for Waymo and follows its two-pronged approach to pushing autonomous driving by delivering people (with ride-hailing service) and goods, Waymo co-CEO Tekedra Mawakana said at Fortune’s Brainstorm Tech summit in Half Moon Bay, Calif., on Tuesday.

The service will first be limited to employees of Waymo and Safeway, which is owned by Albertsons, before opening up for other customers. 

Deliveries are not new for Waymo Via, the company’s delivery system. It has been delivering goods in Phoenix for several years in partnership with UPS, AutoNation, and even trucking company J.B. Hunt. However, San Francisco’s hills, crowded streets, and wetter weather present new challenges for Waymo Driver, the technology in the driver’s seat. 

“We don’t call it driverless, because it’s the Waymo Driver,” she said. “That’s the thing that’s taken all this time to develop and build.” 

In short, it is not just a brick on the gas pedal. 

Waymo Driver is the technology behind both Waymo Via and Waymo One, its ride-hailing service. The company doesn’t plan on making cars, but eventually it does expect to license its technology to carmakers, some of whom already are working on their own autonomous-driving systems, she said. 

Regardless, there will be plenty of room to compete. “Not everyone is going to make it,” she said. “This is really hard.” 

Waymo One has been shuttling people around Phoenix for several years and has completed nearly 100,000 rides with its fleet of a few hundred cars. That is nowhere near the demand of human-driven services Uber or Lyft, but it is winning over skeptics, Mawakana said. 

“When the most skeptical people go in the car and they come out, they say two things every time,” she said. “One, ‘Well, that was just a ride,’” and “Two, ‘The future is here.’”

Ride hailing came before deliveries because of its bigger market and the company’s commitment to improving road safety. 

“Our hypothesis is that this technology can help change people’s lives for the better,” Mawakana said.

The World Health Organization estimated that 1.35 million people around the world died in road traffic accidents in 2018. That works out roughly to a fully loaded Boeing 737-800 falling out of the sky every hour of every day every year. 

The number is far lower in the U.S.—about 32,000 a year, according to the CDC. 

Either way, “the point is that it’s too many people that won’t be at dinner tonight,” she said. 

Unlike plane crashes, though, the deaths are spread out, so countries are not forced to grapple with them as mass casualty events, which skews how societies consider their comfort with autonomous-driven cars, Mawakana said. Sometimes people like to question me on why should they be comfortable with the technology, and my question is, ‘Why are we comfortable with the deaths?’”