Waymo announced today that it's partnering with the Phoenix area's regional public transportation authority, Valley Metro, in order to explore whether self-driving vehicles are an effective way to get people to and from public transportation. Starting in August, Valley Metro employees will be able to hail a Waymo ride via the company's app for their first- and last-mile transit connections. Waymo said in its announcement that as cities grow, "the'last mile' -- how people connect to public transportation efficiently, affordably and safely -- is one of the main challenges communities struggle to solve." With its Valley Metro partnership, Waymo aims to test how autonomous vehicles can help fill those mobility gaps. Following the first phase of the partnership, Waymo will then open up its transportation service to those using Valley Metro's RideChoice service, which provides discounted rides to seniors and people with disabilities.