Automatic emergency braking (AEB) works well to prevent slow speed, rear-end crashes, but struggles to avoid higher speed rear-end crashes and fails to avert T-bones and left turn crashes, reports new AAA Automotive research.
Using forward-facing cameras and sensors, AEB systems automatically tell cars to apply brakes when a frontal crash is imminent. As of September 2022, the technology is standard in most new cars sold in the US. Prior research found AEB has successfully reduced rear-end crashes.
In its research, AAA wanted to see how AEB fared under higher speeds of 30 and 40 miles per hour compared to currently mandated crash speeds of 12 and 25 mph in tests. It also tested the system’s performance when a car turned left in front of oncoming traffic and when cross traffic entered a vehicle’s path, two scenarios that account for 40% of total fatalities in crashes involving two-passenger vehicles where the striking vehicle didn’t lose traction or leave the roadway before the collision.
Here’s what the AAA research found:
- At 30 mph, AEB prevented rear-end collisions 85% of the time.
- At 40 mph, the technology only prevented rear-end crashes 30% of the time but the impact speed when a crash occurred was still reduced by 62%, which helped mitigate crash severity.
- In both T-bone crashes and unprotected left-turn situations, AEB failed to alert the driver and slow the vehicle 100% of the time.
To improve these systems, AAA recommends automakers improve overall system design and test protocols to better represent the deadliest crashes and to assist drivers in intersection-based crash scenarios.
AAA cautions, however, drivers should also recognize the limitations of AEB systems and remain engaged while behind the wheel.
In its testing, AAA used four cars: a 2022 Chevrolet Equinox LT with “Chevy Safety Assist;” a 2022 Ford Explorer XLT with “Pre-Collision Assist with Automatic Emergency Braking;” a 2022 Honda CR-V Touring with “Honda Sensing;” and a 2022 Toyota RAV4 LE with “Toyota Sensing.”