Tesla workers are already hailing robotaxis as part of a test program, Musk says. But a full-blown service requires regulatory approval and could face challenges.

Tesla has been testing a robotaxi service in the Bay Area for the past few months, Elon Musk said during the company’s earnings call Wednesday.

Weeks after investors slammed Tesla for a splashy robotaxi event that was light on details, Tesla executives divulged key details Wednesday about the planned autonomous ride-hailing service—including revealing that the company is already testing the service with its employees in the San Francisco area.