Waymo’s robotaxis began carrying passengers Tuesday through parts of Atlanta in an expansion of a partnership with Uber that began earlier this year in Austin, Texas.

Waymo’s robotaxis in Atlanta will be dispatched through Uber’s app. Uber will give customers a choice to request a car operated by a human if they don’t want to take a driverless ride. The robotaxis will cover a 65-square-mile area within the Atlanta market before expanding to a larger stretch.

Waymo’s ride-hailing app is available in Phoenix, Los Angeles and a swath of the San Francisco Bay Area. Factoring in its partnership with Uber, Waymo is providing more than 250,000 paid rides per week — making it the early frontrunner in the still-nascent robotaxi market. — Associated Press