Waymo, a subsidiary of Google-parent Alphabet which is developing autonomous vehicles and related services, has officially expanded its reach and is now making some of its self-driving minivans available for customers of ride-share firm Lyft.

The rides are restricted to a small area just outside of Phoenix, Arizona, where Waymo has been testing self-driving vehicles and has started its own autonomous ride-share service called Waymo One.

Waymo's limited partnership with Lyft is the latest example of the company branching out to work with more companies as it develops autonomous vehicles and services. Earlier this month, Waymo struck a deal with Nissan and Renault to build self-driving vehicles for those automakers.

By partnering with Lyft, Waymo CEO John Krafcik believes the relationship gives both companies "the opportunity to collect valuable feedback." For Waymo it will be able to better gauge how the public interacts with a self-driving vehicle. Until now, those getting rides in Waymo vehicles in the Phoenix area have been pre-screened and accepted into the Waymo early rider program.

Waymo's steady expansion comes as competitors are making their own plans to roll autonomous ride-share services. Later this year, General Motors subsidiary Cruise, is expected to unveil an autonomous ride-share service in a small area in or near San Francisco.

Uber, which dominates the ride-share industry in the U.S., is also working on its own fleet of self-driving vehicles. Earlier this month, Eric Meyhofer, the head of Uber's Advanced Technologies Group, told CNBC his company is working to deploy self-driving cars without safety drivers in limited areas. But he said Uber wants to be in "the good graces of public trust and regulatory trust" before deciding when to roll out Uber vehicles without someone behind the wheel.

Michelle Krebs, an analyst for Autotrader, believes widespread deployment of self-driving vehicles, whether in a ride-share program or elsewhere, is still years from happening.