About 40,000 people die in traffic crashes in the US each year.

Enter federal regulators: Amid a broader effort to tackle a worrisome uptick in traffic fatalities, they hope to reduce that figure by requiring automakers to install automatic emergency braking (AEB) across their passenger vehicle fleets by 2029. Already, about 90% of new vehicles are equipped with AEB after automakers voluntarily agreed to add the technology, according to the Associated Press. But the Bipartisan Infrastructure Law required the establishment of minimum performance standards for the systems.

The mandate, finalized by the National Highway Traffic Safety Administration (NHTSA) in April, is aimed at reducing rear-end crashes and collisions with pedestrians. The Alliance for Automotive Innovation (AAI), an automotive industry lobbyist, has petitioned NHTSA to “reconsider” the rule. Traffic safety advocates, meanwhile, say the government’s efforts need to move quicker and employ other technologies, as well.

Stefan Heck, founder and CEO of Nauto, which uses AI to help fleet operators improve safety, told Tech Brew he’s in favor of mandatory AEB—but that regulators should look to tackle the issue more holistically.

“I think there’s still a problem,” he said, “which is, the regulations are focused on only a small number of issues and not on the biggest root cause of all, which is distraction.”

In 2021, traffic deaths jumped 10.5% YoY, according to the AP, the largest percentage increase since 1975 and the highest number of deaths since 2005. While 2023’s traffic deaths fell 3.6% YoY, some 41,000 people were killed.

AEB works by using sensors to detect when a vehicle is about to crash into a vehicle or person in front of it, and then automatically engages the brakes. Federal officials estimate that mandatory AEB could save 360 lives per year and prevent some 24,000 injuries.

The rule requires that all cars “be able to stop and avoid contact with a vehicle in front of them up to 62 miles per hour,” and that the systems are capable of detecting pedestrians “in both daylight and darkness,” per NHTSA. It also requires that the system “apply the brakes automatically up to 90 mph when a collision with a lead vehicle is imminent, and up to 45 mph when a pedestrian is detected.”

The technology “is proven to save lives and reduce serious injuries from frontal crashes, and…is now mature enough to require it in all new cars and light trucks,” Sophie Shulman, NHTSA’s deputy administrator, said in a press release announcing the standard.

Although most new vehicles on the road today come equipped with AEB, one of the industry’s arguments against NHTSA’s rule is that it would be difficult to achieve the minimum performance requirements with today’s tech.

In a letter to Congress, John Bozzella, CEO and president of the AAI, objected to elements of the standard, saying that it would be “practically impossible with available technology.” He predicted that “driving AEB-equipped vehicles in the US under NHTSA’s new standard will become unpredictable, erratic, and will frustrate or flummox drivers.”

Indeed, the AEB systems that are available today have demonstrated mixed results, The Verge reported.

Still, the new rule has gotten positive feedback from traffic safety advocates, though some would like it to go into effect sooner.

The Insurance Institute for Highway Safety and the Highway Loss Data Institute lauded the rule in a statement but said that the “long runway provided for compliance is unnecessary.”

Another one of the concerns about mass adoption of AEB is that the technology can result in phantom braking, in which the vehicle brakes despite there being nothing in front of it.

Ram Machness, chief business officer of Arbe, a radar technology company, said that he expects automakers to pursue more advanced imaging radar technology in the coming years.

“You need to be really sure and have consistent detection of the obstacle in order to be sure that you’re not pulling the brakes for nothing,” he said. “If that will be the case, people will disable this feature, or they just won’t trust it.”

The technology that’s widely available today, he explained, is good at detecting moving objects. It’s not as good at reacting to stationary objects—for example, someone dealing with a flat tire on the side of the road.

Heck is a proponent of combining multiple technologies—like AEB and driver monitoring systems—to improve safety and reduce various risks like speeding, drowsiness, impaired driving, and distraction. Nauto data suggests that distraction is responsible for more than 65% of crashes.

“We shouldn’t be looking at these technologies in isolation,” he said. “We should be really looking at combinations that are more powerful.”

He suggested that AEB systems haven’t been wholly effective thus far, in part because drivers often disengage the systems: “Upshot is, I think AEB works. It’s going to prevent one out of 10 collisions, roughly. That’s why Europe’s doing it; I think we should do it in the US. And we should make the interfaces clear and simple, and we should make sure if they’re turning off other features, they’re not accidentally turning off the AEB as well.”