Alphabet Inc.’s Waymo is launching a new account type that lets teenagers hail a robotaxi and ride alone, expanding its rider base while continuing to test its service in more US cities.

Waymo, Alphabet's (NASDAQ:GOOG) (NASDAQ:GOOGL) robotaxi unit, is offering accounts for teenagers aged 14-17 to hail fully autonomous rides in Metro Phoenix, Arizona. Teens in the area can travel independently with Waymo when linked to a parent or guardian's account,

Waymo said it will offer “specially-trained Rider Support agents” during rides hailed by teens and loop in parents if needed.