SAN RAMON, Calif. — General Motors’ self-driving car company is sending out vehicles with nobody behind the wheel in San Francisco as it navigates its way toward launching a robotic taxi service that would compete against Uber and Lyft in the hometown of the leading ride-hailing services.

The service still being developed by GM’s Cruise subsidiary will rely on a boxy, electric-powered vehicle called “Origin” that was unveiled late Jan. 21 in San Francisco amid much fanfare.

SAN FRANCISCO — Elon Musk is taunting the government regulators who threatened to oust him as CEO of electric carmaker Tesla just days after he settled a case alleging he duped investors.