General Motors faces pushback over its request that U.S. regulators waive some automobile safety standards to make it possible to deploy a ride-sharing fleet of driverless cars without steering wheels or other human controls.

GM first made the request for a two-year temporary waiver on features like mirrors, dashboard warning lights and turn signals designed for a human driver in a petition filed with the National Highway Traffic Safety Administration (NHTSA) in January 2018.

The largest U.S. automaker said it hoped to deploy no more than 2,500 modified Chevrolet Bolt electric vehicles as part of a controlled on-demand ride-sharing fleet, likely to be based in San Francisco, by the end of 2019.

In March, NHTSA made the petition available for public comment for the 60 days that ended on Monday.

Several groups, including car dealers and insurers, raised questions posted publicly this week pressing NHTSA to demand more data, require additional safety provisions or deny the petition outright.

The National Association of Mutual Insurance Companies said driverless vehicles without human controls should not be permitted on public roads until data proves the cars are safe.

“NHTSA has no business enabling (automated vehicles) to operate on the roads, and surely has no business removing federally mandated vehicle safety standards to a vehicle that they do not know if it’s as safe as existing vehicles,” said the group, which represents 43 percent of U.S. auto insurers.

The Insurance Institute for Highway Safety (IIHS) said GM should not be allowed to withhold safety features like high-beam headlights from the vehicle and should design the vehicle to require passengers to wear safety belts.

Backers of GM’s plan include Mothers Against Drunk Driving, the National Federation of the Blind, the Telecommunications Industry Association and American Trucking Associations, which say autonomous vehicles have the potential to drastically cut the toll from car crashes.

More than 37,000 people were killed and 2.7 million injured in 6.4 million crashes on U.S. roads in 2017. NHTSA says human error is a critical factor in more than 90 percent of all crashes.

The American Association of Motor Vehicle Administrators said NHTSA should also should require driverless vehicles to “utilize some sort of signage or a universal indicator to alert first responders, potential passengers and other road users that the vehicles do not comply with federal safety standards.”

The Union of Concerned Scientists said the automaker should produce more data on how GM self-driving cars on the road now are performing with backup safety drivers and called for the petition to be rejected.

GM self-driving test vehicles in California with a backup driver in the front seat have been involved in at least 69 traffic collisions, the group said.

Although not all the crashes occurred when the vehicle was in self-driving mode and there was little evidence the cars were at legal fault, UCS said details suggested GM’s self-driving car at times “does not conform to typical driver behavior, leading to confusion or frustration among other road users.”

GM spokeswoman Jeannine Ginivan declined to address specific comments. “We will review the many comments received and respond as appropriate,” she said.

NHTSA said on Wednesday it would also seek public comment “on the removal of unnecessary regulatory barriers to the safe introduction of automated driving systems” as part of its wider efforts to draw up a body of regulations for self-driving cars.