AAA Finds that Automatic Braking Fails in Highway Situations

Automatic Emergency Braking has demonstrated its efficacy in urban driving, but a new test by the AAA finds current systems are ineffective at highway speeds.

Dan Carney, Senior Editor

October 6, 2022

2 Min Read
A 2022 Chevrolet Equinox strikes the target in this emergency braking test.Image courtesy of AAA

On the heels of an Insurance Institute for Highway Safety report finding that automatic emergency braking (AEB) systems offer little benefit in the dark comes a AAA report that says also fails during daylight when it comes to higher speeds and cross traffic.

“AEB systems use lidar, radar, camera or a combination of all three to detect an impending crash in the road ahead,” explains Thatcham Research, the British insurance industry’s equivalent to the IIHS. “A Forward Collision Warning alerts the driver and, if they fail to react, the system applies the brakes automatically to reduce the impact speed or avoid the crash altogether.”

AEB systems have demonstrated their benefit in reducing the incidence of low-speed rear-end crashes, and carmakers have pledged to make it standard equipment on all their cars in the U.S. But that doesn’t mean AEB is a panacea for road collisions.

“Automatic Emergency Braking does well at tackling the limited task it was designed to do. Unfortunately, that task was drawn up years ago, and regulator’s slow-speed crash standards haven’t evolved,” said Greg Brannon, director of AAA’s automotive engineering and industry relations. “Testing requirements for this technology, or any vehicle safety system for that matter, must be updated to handle faster, more realistic speeds and scenarios with the greatest safety benefit for drivers.”

Related:IIHS Flunks Half the Class in Nighttime Collision Avoidance

To quantify AEB’s shortcomings, AAA staged some crash tests, which found:

  • At 30 mph, AEB prevented a rear-end collision for 17 of 20 test runs, or 85 percent. For the test runs that resulted in a crash, the impact speed was reduced by 86 percent.

  • At 40 mph, AEB only prevented a rear-end crash in 6 of 20 test runs, or 30 percent. For test runs that resulted in a crash, the impact speed was reduced by 62 percent.

  • In both the T-bone and left-turn in front of oncoming vehicle tests, crashes occurred 100 percent of the time. AEB failed to alert the driver, slow the vehicle’s speed and avoid the crash.

The vehicles used for these tests were typical model year 2022 American family cars: Chevrolet Equinox LT, Ford Explorer XLT, Honda CR-V, and Toyota RAV4.

Thatcham says that three-quarters of collisions in urban driving environments occur at speeds of less than 25 mph, which is right in the wheelhouse of existing AEB systems. This has led to a 38 percent reduction in real-world rear-end crashes according to a 2015 Euro NCAP study. In fact, since 2019, AEB has been required for vehicles to earn an NCAP five-star safety score.

Related:How the IIHS Offset Crash Test Works

About the Author(s)

Dan Carney

Senior Editor, Design News

Dan’s coverage of the auto industry over three decades has taken him to the racetracks, automotive engineering centers, vehicle simulators, wind tunnels, and crash-test labs of the world.

Sign up for the Design News Daily newsletter.

You May Also Like