Federal auto safety regulators are investigating Tesla’s newly launched Cybercab robotaxis, just one day after the company began offering rides in the futuristic vehicles in Austin, Texas.

The National Highway Traffic Safety Administration opened an investigation on Friday into approximately 1,000 Cybercabs that Tesla plans to deploy. 

The two-seat vehicles are designed to operate without a human driver and have no steering wheel, brake pedal, accelerator pedal or conventional mirrors.

NHTSA said it will examine “the process and technical data” that Tesla had used to certify that the Cybercab was fully compliant with federal motor vehicle safety requirements.

Regulators are specifically questioning whether Tesla was correct in determining that certain federal standards did not apply to the unusual driverless vehicle design.

Tesla reportedly used a self-certification process to determine that the Cybercab meets applicable federal requirements. 

The company has said it plans to expand its robotaxi service to additional locations beyond Austin. 

Cybercabs were recently spotted roaming the streets in the Washington, D.C. area.