NEW YORK — Waymo is allowing the general public to hitch a ride in its driverless autonomous vehicles in Phoenix, expanding a service it had been quietly offering to a select group of riders for the past year.

The service launches to the general public today. The vehicles, which will have no back-up drivers behind the wheel to take over in sticky situations, will serve an area of 50 square miles. There won’t be anyone watching remotely who can take over in an emergency and drive the car.

Before the coronavirus struck, which reduced demand for rides, Waymo was providing 1,000 to 2,000 rides in autonomous vehicles per week. Most of the rides had a backup driver behind the wheel, but 5% to 10% of the rides were fully virtual, available only to a smaller group of riders who signed non-disclosure agreements. Waymo did not disclose how many fully autonomous vehicles will be available to the public in the Phoenix area.

“We are worried about our ability to meet demand with the capabilities of the vehicle we have right now,” CEO John Krafcik said in a conference call with reporters.

Waymo is hoping to eventually expand the service into California, but does not yet have concrete expansion plans to announce, Krafcik said.

Waymo, a unit of Google parent Alphabet Inc., has been running an autonomous vehicle service with selected riders since 2018.

To help encourage safety during the pandemic, Waymo provides wipes and sanitizing gel in the car and asks riders to confirm in a checklist that they haven’t been exposed to the coronavirus. Waymo requires riders to wear masks and checks that masks are being worn using cameras inside the car. The vehicles also have an air circulation feature that helps remove germs that other riders may have introduced.

For the next several weeks, every Waymo ride in the Phoenix area will be without a backup driver. After that, Waymo will re-introduce human backup drivers behind the wheel in some of the vehicles so the company can work on expanding its service area.