Autonomous Emergency Braking

Autonomous emergency braking systems (referred to as both AEB and AEBS) can alert the driver to an imminent crash and can help him use the maximum braking capacity of the car, and which can also apply the brakes independently of the driver if the situation becomes critical.

AEB is known to show a significant reduction in low speed rear-end crashes around the world. Research by Euro NCAP and ANCAP (partly funded by the Australian Government) found “a surprising 38 percent overall reduction in real-world, rear-end crashes for vehicles fitted with low speed AEB….”[1] Similarly, research conducted by the US Insurance Institute for Highway Safety (IIHS) found that “Vehicles equipped with these systems consistently show lower rates of claims for damage to other vehicles and for injuries to people in other vehicles.” The IIHS evaluated systems from Volvo, Honda and Subaru. The analysis indicated that vehicles fitted with AEB reduced body injury liability by up to 35 per cent.[2]

Manufacturers selling vehicles in Australia are increasingly fitting this and other safety technology into the models they are bringing to the Australian market. Currently around 30% of all new passenger cars and 20% of all new SUVs being delivered to the market in Australia are fitted with AEB. The fitting rate has doubled over the last 12 months and it is expected to continue to increase with the introduction of new models.

Fitting rates in Australia are comparable to major European markets and the US market. Thatcham Research, the UK insurers’ automotive research centre, estimate that around 30% of new (UK) cars have AEB available, but two thirds are optional. Similarly, the IIHS estimated that 212 out of 784 2015 passenger car models had “autobrake” available.2

The most basic form of AEB (and the most common) can only detect other vehicles at low speeds (typically in a speed range from about 5 km/h to 30-50 km/h).  The more sophisticated AEB systems detect other vehicles over a much wider speed range than the basic AEB systems (i.e. can detect other vehicles at much higher speeds than the basic AEB systems).

At this stage, there are not many AEB systems in the market that can detect pedestrians [and in some cases other vulnerable road users (VRUs) such as cyclists]. AEB systems that can detect pedestrians (and other VRUs) are the more sophisticated AEB systems that can detect other vehicles over a much wider speed range than the basic AEB systems and  can also detect pedestrians (and other VRUs). However, some of these systems cannot detect pedestrians or other VRUs at night.

AEB is often included as part of a package of advanced driver assistance systems (ADAS) that include emerging safety technology such as forward collision warning, blind spot warning systems,  lane departure warning systems and lane keeping assist systems.


[1] Fidles et al, Effectiveness of low speed autonomous emergency braking in real-world rear-end crashes, Accident Analysis and Prevention, August 2015
[2] Insurance Institute for Highway Safety (IIHS), Stopping Power: IIHS rates 19 new models for front crash prevention, Status Report Vol. 50 No. 7, August 26, 2015