Hit the Brakes

Reverse Automatic Emergency Braking Isn’t Foolproof 

ORLANDO, Fla. (Feb. 15, 2024) – Recent AAA research examined various simulated collisions across four popular 2023 model-year vehicles equipped with reverse automatic emergency braking (AEB) with rear cross traffic mitigation.  

The Inquiry

Reverse automatic emergency braking (AEB) systems have been shown to significantly reduce rear-end collisions. Reverse AEB with rear cross traffic mitigation systems are designed to mitigate or prevent collisions with other vehicles, with some reverse AEB systems detecting rear cross-traffic and automatically applying brakes in response to other cars, pedestrians, cyclists or stationary objects. AAA Engineers wanted to know how reverse AEB systems perform when 1) backing out of a parking space into the path of an oncoming vehicle with an adjacent parked vehicle blocking the view. And 2) while encountering a stationary child pedestrian behind the vehicle. 

The Results

1) Reverse AEB systems automatically applied brakes in 65% of test runs and prevented a collision in 2.5% of test runs in the context of the backing-up scenarios involving a subject vehicle crossing behind the test vehicle. 2) With the stationary child target behind the test vehicle, reverse (AEB) automatically applied brakes in 75% of test runs and prevented a collision in 50% of test runs. 

“Drivers should not solely rely on these advanced driving systems to prevent collisions, but instead use them to enhance their awareness of their surroundings and support safe driving,” said Greg Brannon, AAA’s director of automotive engineering. “Above all, vehicle testing requirements for these systems should be updated to be consistent, taking into consideration unusual objects and more realistic scenarios with the goal of achieving the greatest safety benefit to drivers, pedestrians and cyclists,” said Brannon.  

AAA Tips

1) Drivers should not rely on reverse AEB systems to prevent collisions when backing up but utilize backup cameras and other sensors to enhance their awareness. 2) Back up cautiously when an object obstructs the view, allowing the ADAS sensors to “see” or detect cross traffic, giving the system more time to see a potential collision and to bring the vehicle to a stop. 3) It’s important to make sure these systems are working properly and repaired accurately. Check out Fixing Advanced Vehicle Systems Makes Up Over One-Third of Repair Costs Following a Crash.  

Locate a repair shop you can trust -> AAA Approved Auto Repair Shop Locator. 

Industry Advice

Testing standards for these systems are lacking in the United States but are crucial to ensure they function properly in real-world scenarios. It’s important to evaluate not only their functionality but also their ability to address different situations that may arise. Taking a balanced approach to testing can help ensure that these systems are safe and effective for all users. 

Quick Look

Soft Car 360 Scenarios B-Roll 
Pedestrian Scenario B-Roll


In partnership with the Automobile Club of Southern California’s Automotive Research Center, AAA selected four popular 2023 model year vehicles equipped with reverse AEB with rear cross traffic mitigation. Only reverse AEB systems with the ability to detect and automatically brake for rear cross traffic were eligible for testing. It was determined that all test vehicles would be small to medium SUVs due to the popularity of these categories. The “2023 Hyundai Tucson Hybrid”, The “Limited AWD 2023 Lexus RX 350 “Premium,” The “2023 Mazda CX-30 2.5 Turbo AWD “Premium Plus Package” and the “2023 Volkswagen Tiguan 2.0T “SEL R-Line.”  

Please refer to the full report for methodology details, including specific testing equipment and test track characteristics.  

About AAA  

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