WASHINGTON — The nation’s top auto safety regulator on Wednesday proposed requiring automatic emergency braking, including pedestrian detection, on all new light-duty vehicles and set minimum performance standards for the systems.

If the proposal is adopted, nearly all U.S. passenger cars and light trucks — with a gross vehicle weight rating of up to 10,000 pounds — would be required to have the crash-avoidance technology three years after the rule is finalized. Tougher requirements would take effect four years after that finalization.

NHTSA projects the proposal, if finalized, would prevent at least 360 deaths and reduce injuries on U.S. roads by at least 24,000 annually.

The agency estimates the proposal would cost automakers nearly $282.2 million annually across their entire vehicle fleet. The cost per vehicle is estimated at $82 for each design cycle change of the model, according to the proposal.

“We know we’re throwing a challenge out here,” Polly Trottenberg, deputy secretary of the U.S. Transportation Department, said at a press event Wednesday. “But we know that a lot of this technology is already pretty well-developed, and this is a time to take things to the next level, to make this technology more universally deployed and more stringent.”

The long-awaited proposal — a direct response to a provision in the infrastructure law passed by Congress in 2021 — arrives as the technology becomes more common across all makes and models, not just luxury vehicles and higher trim levels.

At least 14 automakers already have met a 2016 voluntary commitment brokered by the Insurance Institute for Highway Safety and NHTSA to equip 95 percent of their light-duty cars and trucks with automatic emergency braking. The commitment calls for automakers to meet the benchmark for models manufactured from Sept. 1, 2022, to Aug. 31, 2023.

NHTSA’s proposal would push automakers — and the technology’s capabilities — even further.

“The technology now is mature enough for us to propose mandating its inclusion in all vehicles, but we’re doing a whole lot more than that,” said Ann Carlson, NHTSA’s chief counsel. “In this rule-making, we’re proposing to require that the systems be much more effective at much higher speeds.”

NHTSA data shows most crashes, injuries and fatalities occur at speeds above 25 mph, Carlson said, adding that the proposal “really dramatically increases what many AEB systems currently do.”

The proposal would require the systems to fully avoid other vehicles at speeds up to 50 mph when a driver fails to react. If a driver brakes, but not enough to avoid a collision, the system would have to fully avoid another vehicle at speeds up to 62 mph.

It also would require light-duty vehicles to be able to stop and avoid pedestrians at speeds up to 37 mph.

“With this proposal, we could change a high-speed crash from a deadly one to a lower-speed crash with minor injuries or just property damage,” Carlson said. “This goes way above the voluntary AEB commitment and sets a significant safety milestone.”

In addition, the automatic emergency braking systems must be able to perform at night, including detecting pedestrians in the dark and stopping the vehicle accordingly.

To be sure, the proposal includes performance-based standards and does not mandate a certain technology, such as cameras, radar or lidar, be used to meet the requirements, said Markus Price, chief of NHTSA’s visibility and injury prevention division.

A 60-day public comment period will be open once the proposal is published to the Federal Register.

The Alliance for Automotive Innovation, which represents most major automakers in the U.S., was still reviewing the proposal but said many of its members already have developed and deployed the crash-avoidance technology, including pedestrian detection, on their vehicles.

“AEB is a breakthrough safety technology that uses radar, cameras and lasers to prevent crashes and save lives that the industry voluntarily committed to install in nearly all new vehicles by 2025,” the group said in a statement. “Several automakers are ahead of schedule on that commitment, and experts predict it could prevent 42,000 incidents and 20,000 injuries annually.”

For years, auto safety advocates have been urging NHTSA to require the technology on all new vehicles and set performance standards.

The Insurance Institute for Highway Safety, which urged federal regulators in March 2022 to require automakers to equip new passenger vehicles with automatic emergency braking technology that can detect and avoid pedestrians even in the dark, said NHTSA’s proposal will lead to improved systems that work properly under more conditions.

“Pedestrian AEB that works well at night is a game-changer for protecting the most vulnerable people on the road,” David Harkey, president of the Insurance Institute for Highway Safety, said in a statement. “This proven technology takes action when a driver doesn’t and can reduce the severity of a collision or prevent the collision from happening altogether.”

Cathy Chase, president of Advocates for Highway and Auto Safety, applauded NHTSA’s action and urged it to finalize a rule “promptly.”

The agency is expected to finalize the rule by November, according to a government website.

“With the clock ticking down on the Biden administration and the number of preventable deaths piling up, there is no time to spare on bringing these rules over the finish line and these safety technologies onto production lines,” Chase said.

William Wallace, associate director of safety policy at Consumer Reports, said the proposal has been “a long time coming” and is “desperately needed.”

“We’ve seen an increase each year in the number of vehicles that offer the technology,” he said, “but ultimately these federal requirements would ensure every new car comes with this proven safety feature — without consumers being forced to pay extra for an expensive option package.”

Automatic emergency braking, part of advanced driver-assistance systems, has the potential to save lives and reduce injuries by stopping or slowing a vehicle to prevent a collision, but for some motorists, it has been problematic.

In 2022, NHTSA opened two separate investigations involving Tesla and Honda vehicles after receiving hundreds of complaints alleging unexpected activation of the automatic emergency braking system, characterized by some Tesla owners as “phantom braking.”