Tesla's driverless Cybercab has come under federal investigation just hours after the company began giving members of the public rides in the two-seater vehicle, which lacks a steering wheel and brake pedals, in Austin, Texas. The US National Highway Traffic Safety Administration (NHTSA) is examining whether the vehicle meets federal safety standards, in a rebuke that observers say reflects growing frustration with Tesla's approach to regulatory compliance ahead of its planned mass rollout of driverless taxis.

Unlike rival Zoox, which secured a formal exemption from federal vehicle rules before deploying its similarly unconventional robotaxis, Tesla has argued it needs no such exemption because the Cybercab already complies with existing standards. The NHTSA's "Audit Query" will scrutinise the data and reasoning behind that claim. A former acting NHTSA administrator described Tesla's stance as "gobsmacking" given the precedent set by Zoox's case. Such investigations can lead to mandated design changes or financial penalties — Volvo, for example, paid $130 million and accepted three years of independent oversight following a past probe. Tesla currently has 45 Cybercabs operating in Texas but has stated ambitions to deploy millions annually as part of CEO Elon Musk's vision of the company as a robotics and autonomous vehicle firm.