Bauer's Intelligent Transportation, the operator of shuttle buses that companies use to pick up and drop off employees, received a permit for testing autonomous vehicles from the California Department of Motor Vehicles.

As of Friday, Bauer's was one of 31 companies with permits from the DMV, and it's an unusual addition to the list. Since California began doling out permits in 2014, the permits have gone to automakers like Ford (NYSE: F) and Tesla (NASDAQ: TSLA) as well as technology companies including Alphabet (NASDAQ: GOOGL), Apple (NASDAQ: AAPL) and Baidu (NASDAQ: BIDU) and ride-hailing leader Uber.

Box (NYSE: BOX), Twitter (NYSE: TWTR) and Zynga (NASDAQ: ZNGA) are among the companies that have used Bauer's Wi-Fi equipped shuttle buses to transport employees.

Alphabet subsidiary Waymo has been piloting self-driving cars for the past few years, and BuzzFeed reported last week that the Google parent also started testing a self-driving truck. Uber created a self-driving car program in 2015, and it became active in truck testing last year through its acquisition of Otto.

Bauer's, based in San Francisco, doesn't have any cars or drivers listed under its permit yet, the DMV said in an e-mail. Bauer's did not immediately respond to a request for comment. In addition to operating corporate buses, Bauer's also transports people for special events.

Vehicles that companies test on public roads under the DMV permit must have a way for a human driver to take control when necessary, and companies are required to file reports about those instances of disengagement.

More From CNBC

• How innovative companies create the campus feel for offices in dense cities
  

• Apple's new business chat app will challenge Facebook Messenger
  

• Grab, Uber's Southeast Asian rival, likely to seek funds, eyes financial services