Waymo is now providing driverless rides between Phoenix’s Sky Harbor International Airport and the city’s downtown area.

The company, owned by Google parent Alphabet, has gradually evolved its operation at the airport over the past year, offering rides to members of staff and then trusted testers, and removing a safety operator from the driver’s seat.

Now it can offer members of the public what it says will be “the only autonomous airport service of its kind in the world, available round the clock with no human driver.”

The service – which uses Jaguar i-Pace models fitted with the company’s Waymo Driver autonomous tech – is available at the 44th Street and Washington Sky Train Station and will run 24 hours a day, seven days a week. Waymo Driver uses a combination of lidar, radar and cameras to deliver automated functionality.

Airports have long been seen as a lucrative opportunity for robotaxi operators, as airport trips have traditionally represented a major portion of business for ride-hailing companies. But they can be chaotic environments that pose major challenges to autonomous vehicles, with large numbers of pedestrians, a wide mix of different vehicles and the use of restricted areas for drop-offs and pick-ups.

At the same time as announcing the breakthrough at Sky Harbor, Waymo also confirmed that it is expanding the 

service areas where members of the general public can catch fully autonomous rides in San Francisco and Phoenix.

The company was keen to point out that “Waymo remains the first and only company to offer fully autonomous trips to members of the public 24/7 and in multiple metro areas simultaneously.” 

Chief rival Cruise, a General Motors subsidiary, is currently only operating in San Francisco, although it does have the approval to charge for driverless rides there. Waymo has applied for permission to do the same but is awaiting a decision from the California Public Utilities Commission.

Currently, Waymo can drive fully autonomously – with nobody behind the wheel – across all of San Francisco at all hours of the day. The service is available to members of the public across most of the city, but only to employees and guests in the downtown area. No fares can be charged, though.

In Phoenix, meanwhile, the company is doubling its service area downtown to 41.2 square miles.

“Our progress in two of the most popular ride-hailing cities in the country is accelerating,” said Saswat Panigrahi, chief product officer at Waymo. “As we add more neighborhoods and vehicles to our service in San Francisco and Phoenix, we’re excited to bring the safety and mobility benefits of round-the-clock autonomy to more people in more places.”

Beyond Phoenix and San Francisco, Waymo has already announced that it plans to expand its service to Los Angeles, although no definitive timeframe has been confirmed.