(Reuters) -Ride-hailing app Lyft and autonomous vehicle startup May Mobility will launch a pilot robotaxi service in Atlanta starting from Wednesday, the companies said, marking the partnership's first public deployment.

Customers using the standard Lyft app will be able to hail Toyota Sienna minivans retrofitted by May Mobility on routes in and around Midtown Atlanta, with fares comparable to regular rides.

The companies will start with a small fleet, with trained in-vehicle operators on board to answer questions and take control if needed.

The rollout underscores Lyft's efforts to integrate self-driving rides into its app through partners, such as Baidu in Europe and Mobileye, even as robotaxi firms race to clear regulatory hurdles and prove they can operate safely and profitably at scale.

"We'll start in the single digits of cars, move up to dozens, and over time to hundreds and thousands," Jeremy Bird, Lyft's executive vice president of driver experience told Reuters. Neither Bird nor May Mobility CEO Edwin Olson gave a timeline for expansion.

Olson said the vehicles feature a redundant drive-by-wire system and a 360-degree sensor suite combining lidar, radar and cameras.

The service will be integrated into Lyft's hybrid marketplace, allowing riders to choose an autonomous trip or a conventional ride.

The Atlanta pilot will be managed by May Mobility and not Lyft's fleet-operations backbone, Flexdrive.

Last month, Lyft convened an AV Driver Forum in Atlanta to brief drivers on the rollout, and both companies said they have engaged with local and state officials.

Among the competition, Alphabet-owned Waymo has expanded paid autonomous services in major U.S. cities, Uber has partnered with tech firms to deploy self-driving taxis globally, and Tesla launched its first robotaxi service in Austin, Texas, and a ride-hailing service in the Bay Area earlier this year.