Uber on December 14 started to use Volvo XC90 unleaded vehicles in San Francisco, trying to expand their pilot program they originally started in September in the US city of Pittsburg. Hours later, the California DMV requested from Uber in writing to stop the San Francisco program until it got the required permit because, according to Brian G. Soublet, the deputy director of this agency, it was illegal to use autonomous vehicles on San Francisco roads without authorisation. "If Uber had obtained a permit to test driverless vehicles before today, the company's launch would have been admissible," Soublet argued, warning that the DMV would initiate "legal actions" if the company did not confirm "immediately" that it would cease operations.