Amazon’s robotaxi company is under investigation after two crashes with motorcyclists

US safety regulators are looking into two crashes involving Amazon’s robotaxi company, Zoox. The Office of Defects Investigation, under the US National Highway Traffic Safety Administration, opened a preliminary evaluation into Zoox after two separate reports of the vehicles suddenly braking and causing motorcyclists to crash into their rear end.

NHTSA confirms that the Zoox vehicles were operating in driverless mode without safety drivers when the incidents occurred. The vehicles involved in both crashes were Toyota Highlander SUVs, which Zoox uses for testing and data gathering. According to the Office of Defects Investigation, the investigation covers an estimated 500 vehicles.

This isn’t Zoox’s first run-in with NHTSA. Last year, the agency investigated claims by the company that its driverless vehicle met federal safety standards without an exemption from the government.