Waymo, the self-driving division of Alphabet, is about to put more passengers its fully driverless Chrysler Pacifica minivans. The company emailed its customers in the suburbs of Phoenix, Arizona, to let them know that “completely driverless Waymo cars are on the way.” It’s a sign that Waymo is growing confident enough in its technology to increase the frequency at which it allows passengers to ride in autonomous vehicles without a safety driver behind the wheel.

The email, which was published on Reddit and confirmed as authentic by a spokesperson, was sent to members of Waymo’s early rider program, a 400-plus cadre of suburban Arizonans who signed nondisclosure agreements with Waymo to test its self-driving cars. Waymo also operates an invite-only commercial ride-hailing service called Waymo One that includes around 1,000 people.

Waymo first demonstrated its fully driverless cars on public roads in Arizona back in 2017. Since then, it has allowed some passengers to ride in these vehicles and even released some promotional videos of these trips — though the bulk of its rides are done with a trained driver behind the wheel. The company has been very strict about the conditions under which it tests its driverless cars for obvious reasons. For example, The Verge took a ride in a fully driverless Waymo vehicle nearly two years ago, but it was on a closed course and not on public roads.

“we’ve begun to responsibly ramp up our driverless offerings.”

Waymo is widely seen as having some of the most advanced technology in the industry. So when the company launched its commercial ride-hailing service in December 2018 with safety drivers in the vehicles, some experts took that as a sign that autonomous vehicles are further away from mass adoption than previously thought. In September, Morgan Stanley slashed Waymo’s valuation by 40 percent citing challenges to rolling out self-driving cars to a wider audience.

But the company maintained that it would eventually deploy more driverless cars — when it was ready. “We’ve been testing at small scale in fully driverless mode since 2017 — with no trained human driver behind the wheel,” Waymo CEO John Krafcik said in Frankfurt recently. “And we’ve begun to responsibly ramp up our driverless offerings to riders in the Metro Phoenix area.”

In the email, Waymo says that riders who get “matched” with a driverless car will receive a notification in their Waymo app that confirms the car will be without a trained driver. “You can enjoy having the car to yourself,” the company says. If they need assistance during the ride, customers can reach out to support staff through the app or via an in-car help button.

We're glad you asked. Each of our fully driverless vehicles drives on its own and without the aid of our team via remote control support. As we ramp up our driverless offerings, we're doing so responsibly with every step we take. — Waymo (@Waymo) October 9, 2019

Riders can’t specifically request a driverless Waymo vehicle. According to a screenshot of a chat with Waymo posted on Reddit (which is proving to be quite the treasure trove of Waymo-related gossip), those matches will be randomly assigned.

(Another Reddit user posted a video recently that shows a driverless Waymo parked on the side of the road in Tempe. It wasn’t clear whether the vehicle was operating in driverless mode at the time, though in light of this email, it’s a fair bet that it was.)

Meanwhile, Waymo is branching out to new cities: the company announced recently that it would begin mapping in Florida and downtown Los Angeles.