Automatic emergency braking (AEB) is pretty good at preventing low-speed rear-end collisions, but sucks when vehicles are traveling at more normal speeds, according to new research from the American Automobile Association (AAA).
From September 2022, all new cars sold in the US must come standard with AEB, which uses forward-facing cameras and other sensors to automatically brake when a crash is imminent. The Insurance Institute for Highway Safety estimates that AEB could help prevent 28,000 accidents and 12,000 injuries by 2025.
Using four regular vehicles, AAA wanted to put AEB to the test to see how it’s progressed since it was first rolled out to production vehicles nearly 20 years ago. What they found wasn’t that great.
“Automatic Emergency Braking does a good job at tackling the limited task for which it was designed,” Greg Brannon, director of AAA’s automotive engineering and industry relations, said in a statement. “Unfortunately, that task was drafted years ago and the regulator’s standards for low-speed crashes have not evolved.”
The group selected four vehicles for testing, all of which were equipped with driver assistance features, including AEB: 2022 Chevrolet Equinox LT; 2022 Ford Explorer XLT; 2022 Honda CR-V Touring; and 2022 Toyota RAV4 LE.
AEB has proven itself over the years in reducing low-speed rear-end crashes, but AAA wanted to see how well it performs in two more common — and more deadly — crash scenarios: T-bones and left turns for oncoming vehicles. From 2016 to 2020, these two types of crash accounted for nearly 40 percent of the total fatalities in two-passenger vehicle crashes where the colliding vehicle did not lose traction or drifted off the roadway prior to impact.
The results were quite discouraging. In both the T-bones and left-hand turns for an approaching vehicle testing, AEB failed to prevent 100 percent of AAA-organized crashes. The system also failed to warn the driver and slow the speed of the vehicle.
In rear-end crash testing, AEB performed slightly better as long as the speed was kept low. At 30 mph, the system prevented 17 out of 20 crashes, or 85 percent. In the test drives that led to a crash, the crash rate was reduced by 86 percent. But at 40 mph, AEB prevented only six out of 20 rear-end collisions, or 30 percent. On test drives that led to a crash, the crash rate was reduced by 62 percent.
This isn’t the first time AAA has highlighted the shortcomings of automatic braking and other driver assistance features. A 2019 study by the group found that AEB was pretty bad at stopping cars traveling at speeds of 20 mph over dummy pedestrians.
These studies will no doubt resonate with automakers who have made eliminating road accidents and fatalities a major goal. Meanwhile, regulators are pressuring the auto industry to do more to prevent reckless driving.