Travelers using the ride-hailing app Lyft can now choose to call a fully autonomous Waymo vehicle for their trips within the city of Nashville, with broader availability set to grow in the weeks ahead, Lyft said today.

The move marks the first market where Waymo vehicles are available across both the Waymo and Lyft apps.

The driverless cars are supported by a Lyft subsidiary called Flexdrive, which provides fleet management services for Waymo in Nashville, as well as for Lyft drivers nationwide.

According to San Francisco-based Lyft, riders can always decline an autonomous ride or opt out of them entirely.

Even as the company increases its use of autonomous vehicles, it says it is planning for a “human-centered autonomous future,” saying it continues to see autonomous vehicles as a supporting layer to the existing community of drivers.