Uber is bringing a small number of self-driving cars to its ride-hailing service in San Francisco - a move likely to excite the city’s tech-savvy population and certain to antagonize California regulators. The Wednesday launch in Uber’s hometown expands a public pilot program the company started in Pittsburgh in September. The testing lets everyday people experience the cars as Uber works to identify glitches before expanding the technology’s use in San Francisco and elsewhere. California law, however, requires a test permit for self-driving prototype vehicles, and Uber does not have one.