Self-driving cars aren’t just great for delivery, highway driving, and long-haul trucking. As researchers at MIT posited in 2011, they have the potential to fill gaps in local transportation — the so-called “last mile” between destinations and public infrastructure like buses, trains, and light rail.

It’s an area of study Google spinoff Waymo intends to explore. It today announced in a Medium post that it’s partnering with the Valley Metro, the Phoenix area’s regional public transportation authority, to “[develop] mobility solutions” that leverage autonomous cars to bridge the gap between public transit and the people who use it.

Waymo hasn’t announced how it’ll eventually charge for the service, but it might be comparable in price to a ride in an Uber or Lyft. Bloomberg reports that the Waymo app currently being tested by members of the company’s Early Rider program began showing hypothetical prices recently, and that one rider’s 11.3-mile trip had an estimated cost of $19.15.

A Waymo spokesperson told Bloomberg that the prices “[do] not reflect the various pricing models under consideration,” and that they’re only meant to “solicit feedback.” In any case, there aren’t currently plans to charge Valley Metro riders.

The first phase of Waymo and the transportation authority’s partnership, which is expected to launch in August, will see customers offered rides to nearby public transportation options in Waymo’s self-driving Chrysler Pacifica minivans, which they’ll be able to hail using the company’s app.

Later this year, the program will expand to Valley Metro RideChoice travelers, whom Waymo notes are “traditionally underserved” by public transit. (RideChoice offers discounted taxi rates to seniors and people with disabilities.) During this second phase of the pilot program, the partners will embark on joint research to evaluate the service’s impact and its long-term potential.

If all goes according to plan, Waymo will extend self-driving transportation to more Valley Metro customers in the future.

“This will form the basis of joint research to evaluate the adoption of Waymo technology, its impact, and its long-term potential to enable greater access to public transit,” Google wrote. “Working together, we want to explore how self-driving vehicles could fill transportation and mobility gaps for riders across the Greater Phoenix area.”

Waymo has made quite a bit of headway in recent months. In March, it launched a logistics test that put self-driving trucks on roads in Atlanta, and in May began discussions with Fiat Chrysler around licensing its autonomous Pacificas for commercialization. And just this month, it revealed new Jaguar Land Rover vehicles that’ll join its fleet later this year.

Last week, Waymo CEO John Krafcik announced that its self-driving cars have driven 8 million miles on public roads and 5 billion miles in simulation. The company has 600 Pacifica minivans deployed on public roads, some of which are being used by the over 400 residents participating in the Early Rider program, and plans to add as many as 82,000 additional vehicles — 62,000 minivans and 20,000 Jaguar I-Paces — in the coming months.