Robot cars are back in the spotlight on Capitol Hill after previous efforts failed to pass comprehensive legislation allowing more autonomous vehicles on the road.

US Sens. Gary Peters (D-MI) and John Thune (R-SD) plan to introduce an amendment to a funding bill that would grant federal regulators the power to exempt tens of thousands of vehicles from requirements to have traditional controls for human drivers, according to Reuters.

The amendment would give the National Highway Traffic Safety Administration (NHTSA) the power to exempt 15,000 vehicles per manufacturer from certain safety standards, with that number increasing to 80,000 in three years. The effect would be to grant more leeway to automakers like Ford and General Motors, as well as tech firms like Google and Amazon, to manufacture and deploy vehicles that lack traditional controls like steering wheels, pedals, and sideview mirrors.

Today, the NHTSA is only legally allowed to grant 2,500 exemptions per manufacturer. The agency handed out its first autonomous vehicle exemption to a California-based company called Nuro in early 2020.

The autonomous vehicle industry praised the introduction of the amendment. A group called the Self-Driving Coalition for Safer Streets, which includes Uber, Lyft, Volvo, Ford, and Waymo as members, said it “welcomes Senators Peters and Thune’s amendment to support autonomous vehicle testing and deployment in the U.S.” The amendment will “pave the way for AV technology to save lives, unlock new economic and mobility opportunities, and promote American leadership and innovation in this globally competitive arena,” Ariel Wolf, general counsel of the coalition, said in a statement.

But some safety groups say the amendment falls short similarly to previous legislation, like the AV START bill, which died after failing to muster enough support in the Senate. Along with trial lawyers and some local officials, they argue that the technology is not ready for prime time and want Congress to empower the NHTSA to require more data from autonomous vehicle operators, such as crash reporting and disengagements of the self-driving software. The trial lawyers, who have an enormously powerful lobbying group, have been blamed for sinking the previous effort to pass legislation.

“The amendment fails to provide consumer protection and instead essentially creates a fast-track process for manufacturers to attest that their driverless vehicle is no more safe than the least safe vehicle on the road today, before being permitted to sell tens of thousands of them and turning them lose in our neighborhoods,” Jason Levine, executive director of the Center for Auto Safety, said in an email. “Throwing open the door to more unregulated testing and underregulated sales without a strong oversight mandate is no way to bolster diminished public trust in driverless technology.”

Cathy Chase, executive director of Advocates for Highway and Auto Safety, said the amendment was “alarming,” and she opposed the effort to pass the legislation as an amendment rather than a standalone bill.

The Peters-Thune amendment would be attached to the Endless Frontier Act, a $100 million spending bill that aims to increase investments in science and technology in order to compete with China and other countries. Peters and Thune are hoping to win the approval from the Senate Commerce Committee on Wednesday when they take up the bill. The Biden administration has signaled its support for the Endless Frontier Act, but not specifically the autonomous vehicle legislation.

The news of the new amendment comes during a week in which two other members of the Senate, Ed Markey (D-MI) and Richard Blumenthal (D-CT), have requested a robust investigation into a fatal crash involving a Tesla Model S in which no one was behind the steering wheel.