Automatic Emergency Braking is Getting More Effective

If you own a car produced in the last five years or so, chances are good that it’s loaded with so many technology features that you may not even be aware of them all, since they work so seamlessly in the background. Systems like Automatic Emergency Braking (AEB) and Adaptive Cruise Control date back more than two decades, but it’s only in the last few years that progress has really taken off. In the case of AEB, roughly 90 percent of new vehicles have the technology.

And things are just getting started.

The world of advanced driver assistance systems, commonly known as ADAS, is changing by the day, driven not just by the march of new technologies but by regulations that are pushing manufacturers to adopt them in their vehicles. “Vehicles are definitely getting more robust,” says Greg Brannon, Director of Automotive Research for AAA, “and automakers are continuing to work towards balancing effectiveness and minimizing the number of times that drivers get false positives.” (False positives occur when safety systems indicate a hazard when there isn’t one.)

Nowhere are these efforts more visible than in one of the most heavily researched ADAS technologies: Automatic Emergency Braking.

New rules are driving major AEB upgrades.

AEB is getting massive attention for good reason: Older AEB systems, even those produced as recently as 2018, just aren’t very effective. New testing from AAA compared a variety of cars from two eras: vehicles from the 2024 model year and vehicles produced in either 2017 or 2018. Researchers put their respective AEB systems through a variety of real-world experiments to measure the effectiveness of these braking solutions.

The results were striking. At speeds of 35 mph and slower, only 51 percent of vehicles produced in 2017 or 2018 were able to automatically stop in time to avoid a crash with a car stopped directly ahead of it. When the same test was undertaken with 2024 model vehicles, 100 percent of the vehicles were able to stop in time. Three out of four test vehicles were able to stop in time to avoid a crash at 45 mph, something that no 2017/2018 model car was able to do. “We can say for sure that we’ve had significant progress in the advancement of these systems,” says Brannon.

While today’s drivers can put considerably more faith in AEB, this technology is slated to become even more capable in the years to come. Federal Motor Vehicle Safety Standard 127, finalized earlier this year, not only specifies that AEB systems be standard on all vehicles by September 2029, but that it must work at speeds of up to 90 mph. That’s something that no manufacturer has come close to reaching yet, and Brannon admits it’s going to be a challenge to achieve in just five years. “We’ve come a long way, but there's still a long way to go between here and there,” he says.

Pedestrian detection is improving.

The new standard doesn’t just outline rules for protecting drivers from getting into accidents with other vehicles, it also specifies that AEB systems need to be effective at protecting pedestrians, especially at night while at speeds of up to 45 mph.

Pedestrian deaths are a huge problem in this country, accounting for more than 17 percent of all traffic fatalities in 2022. Between 2010 and 2022, pedestrian deaths increased 77 percent, while traffic fatalities rose by 22 percent.

Part of the problem is that averting pedestrian accidents represents a significantly more difficult challenge for manufacturers to solve with technology, due to the much smaller size of a person compared to another car, not to mention the different sizes of a person and their potential position (sitting down, for example).

“Pedestrians don’t have seatbelts and airbags. This is a tragedy that's getting worse,” says Brannon, “and rising distraction levels are probably to blame for that. The good news is that AEB technology has the potential to reduce that number significantly, and the better we get at it, the more lives will be saved.”

Get the most out of your AEB system.

AEB isn’t something you can easily experiment with, because if it doesn’t work, you can easily get into a lot of trouble. But most drivers will eventually encounter an AEB situation on the road when someone abruptly stops in front of them, but there are ways to know if your system is working before then.

Short of testing with a collapsible target the way AAA did, the best way to see if your car’s detection systems are functioning as they should is to experiment with adaptive cruise control, assuming your car has the feature. If your car successfully adjusts its speed to match that of the car in front of you, you can be sure its sensors are working properly.

But most of all, getting comfortable with AEB will be a simple by-product of time spent on the road. Last year AAA issued a report suggesting that all ADAS technologies were improving largely because drivers were getting more familiar with them. In other words: Practice makes perfect.