Automatic emergency braking (AEB) in vehicles consist of two separate systems, one for the front brakes and one for the rear; both of these work in similar ways. The front uses sensors, and sometimes a camera, to detect oncoming obstacles, and to determine if a collision is going to happen if the driver does not apply the brakes to stop the car, the AEB comes into effect and stops the car before an accident occurs. The rear AEB works very similarly but usually does not deploy cameras, but instead relies on sensors and often works in conjunction with the blind spot detection system and the RTCA system.
In general, there are two types of AEB available to drivers:
Just like many safety systems, it should not be relied upon solely, but rather used in conjunction with the drivers own sensibilities. It is a fantastic system and something that most car manufacturers, and insurers, are satisfied with the testing results.
In America, the Insurance Institute for Highway Safety concluded that the use of AEB systems in cars has reduced collisions by an estimated 50% in front-rear end accidents.
In regards to rear AEB, the research has shown that it has reduced rear-end collision, occurring while the car was reversing, to have reduced by as much as 78%.
While the AEB systems are incredibly sophisticated, they are let down by their inability to detect people, adults and children, cyclists, animals, and other smaller moving objects.
The risks of a higher amount of pedestrian accidents may occur if drivers become too reliant on the system doing the work for them. Therefore it is advisable that all drivers remain alert and not think that the AEB system will protect them from all accidents.
There have also been a few reports of the system malfunctioning and triggering the brakes even though there was no imminent danger. When this happens it could have been caused by a damaged sensor.
Cars with AEB have a wide variety of systems in place that all work together. If your car has rear blind spot detectors, and RCTA, then the car may have rear AEB, as these systems are regularly coupled together.
If in doubt you can contact your car manufacturer, or search an online database to find out your specific questions.