Automatic emergency braking (AEB) systems have proven to be very helpful in reducing numbers of crashes. A past IIHS study found that cars with automatic emergency braking were in 50% fewer rear-end collisions.
There are limits to these systems, and specifically in areas where collisions are fairly common. AAA has found that higher speeds and particular types of collisions need improvement.
The situations AAA tested included rear-end collisions at higher speeds than IIHS currently tests. AAA found that 60% of rear-end crashes that result in injuries happen in areas with speed limits between 30 and 45 mph. As such, it tested systems at 30 mph and 40 mph with stationary dummy vehicles.
AAA also tested with the other two most common injury-causing two-vehicle crashes that, when combined with rear-end collisions, result in 79% of injury-causing wrecks: T-bone collisions, and collisions with an oncoming car turning across traffic.