All new cars must have automatic braking systems by 2029 under new federal rules

Federal safety standards issued Monday will require new cars to have automatic emergency brakes that can bring them to a complete stop without crashing or hitting pedestrians even at high speeds, saving hundreds of lives a year.

Automakers will have until the fall of 2029 to comply, but officials at the National Highway Traffic Safety Administration said they expect the industry to be able to deploy the systems ahead of the deadline.

“Automatic emergency braking is proven to save lives and reduce serious injuries from frontal crashes, and this technology is now mature enough to require it in all new cars and light trucks,” NHTSA Deputy Administrator Sophie Shulman said in a statement. “In fact, this technology is now so advanced that we’re requiring these systems to be even more effective at higher speeds and to detect pedestrians.”

The rules are one of the most significant changes to car safety standards in years and are being issued in the midst of a road safety crisis that saw 41,000 people killed in 2023. Automakers have been installing a lower-speed version of automatic emergency brakes in almost their entire fleet under a deal struck during the Obama administration. But the new regulations are aimed at ensuring far higher performing systems become the standard, and have faced objections from the industry.

Automatic emergency brakes rely on sensors in the vehicle to detect when a crash is imminent and either take over the job of applying the brakes entirely or help a driver safely come to a stop. The rules call for the systems to be able to bring a vehicle traveling at up to 62 mph to a complete stop without causing a collision. They should also be able to apply the brakes if a pedestrian is detected at speeds of up to 45 mph.

NHTSA estimates the rules will prevent 362 road deaths per year and reduce the severity of 24,321 injuries. The agency has said most vehicles could comply with the standards through updates to their software.

Cathy Chase, the president of Advocates for Highway and Auto Safety, said the new rules were a “major victory for all consumers and public safety.”

But the auto industry expressed concerns with key parts of the rule after it was proposed last year, arguing it would be impractical in the short term to require that the systems could avoid crashes altogether.

The Alliance for Automotive Innovation, an association of automakers, urged NHTSA to consider an alternative involving reductions in speed in some cases. “Significant hardware and software changes will be needed to achieve a level of performance that no production vehicle can currently achieve,” the organization said last year.

The final version of the rules gives the industry an additional year to comply compared with NHTSA’s original proposal, but maintains the same performance requirements.

New test results from the Insurance Institute for Highway Safety, a research group, suggest the systems will have to improve in coming years to meet the federal rules. The institute said last week it had tested crash avoidance systems on 10 small SUVs at speeds of up to 43 mph, finding that many failed to stop in time to avoid a crash in the most difficult test scenarios.

Just one vehicle, the Subaru Forester, earned a rating of “good” from the organization because it was able to avoid a car ahead of it and dramatically slow down for a motorcycle. The Honda CR-V, rated “acceptable,” avoided the car but struggled to brake for the motorcycle at the highest speed in the test.

The new braking rules were required as part of the 2021 infrastructure law, which pushed NHTSA to use new technology to tackle road deaths. The agency is also exploring a requirement that vehicles be equipped with technology to block drunken driving. The work is in its early stages, but supporters say alcohol detection technology could save 10,000 lives per year.

NHTSA is also working with the Federal Motor Carrier Safety Administration, a truck safety agency, to require automatic brakes on heavy-duty vehicles.