Waymo begins offering rides via Lyft

The pilot program is limited to a Phoenix suburb.

Waymo has begun offering autonomous taxi rides via Lyft's ride-sharing app in of Phoenix.

Following an official announcement of the partnership, Waymo has now confirmed to CNBC that the pilot program has quickly kicked off in a relatively small suburb of Phoenix where Waymo had been offering rides through an invite-only program.

At this point, Waymo is only using 10 or less vehicles to serve Lyft riders within the service area. The rides are only being offered to users who choose an origin and destination within the 'geofenced' region.

Waymo is viewed as a leader in the push toward autonomous taxi services. The company is moving forward cautiously, however, with a human safety driver behind the wheel during the trail program.

The partnership between Waymo and Lyft allows the former to learn more about an established ride-sharing service while the latter gauges customer interest in autonomous vehicles. It is unclear if the companies plan to expand the partnership as Waymo expands its service into new regions in the coming years.