Federal regulators are opening an investigation into whether Tesla's new steering-wheel-free taxis comply with safety rules a day after the company began offering rides in the vehicles.

The National Highway Traffic Safety Administration said it was looking into whether Tesla was in full compliance with federal rules in deploying so-called Cybercabs in Austin, Texas, given that the two-seater cars lack steering wheels, mirrors or brake pedals typically required of all vehicles.

The head of the company, Elon Musk, kicked off his Cybercab service in Austin on Thursday with fanfare, sending dozens of the futuristic taxis into the city streets and holding a launch event for invitees.