Senator Ed Markey's probe into the autonomous vehicle (AV) industry reveals a patchwork of safety practices, with companies tight-lipped about how often their driverless cars need human assistance on the road.

The seven companies surveyed—Aurora, May Mobility, Motional, Nuro, Tesla, Waymo and Zoox—refused to disclose details about the frequency or nature of remote guidance. Waymo's Mauricio Peña hinted at the reality during a Senate hearing, but specifics remain scarce.

Markey's office criticised these companies for their lack of transparency, particularly regarding overseas operators who may not meet U.S. driving standards. Tesla, for instance, admitted to letting its remote assistance workers take control under certain conditions, though only at low speeds.

The investigation highlights the challenges in regulating AV technology as it moves from testing grounds to real-world commercial use. Markey is now pushing for stricter federal oversight and legislation to guard against potential risks.