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Auto Emergency Braking (AEB)

What is AEB?

Auto Emergency Braking (AEB) is a vehicle safety technology has the potential to prevent a crash or reduce the impact speed of a crash.

AEB can:

  • Alert the driver to an imminent crash and help them use the maximum braking capacity of the car and
  • Apply the brakes independently of the driver if the situation becomes critical

It is important to note that AEB systems are designed to support the driver only in emergency situations and that the driver remains responsible for the vehicle at all times.

The experts discuss AEB

 AEB systems use sensors, radar, laser or cameras to monitor for risk and detect potential collisions with other vehicles, pedestrians or hazards.

Although AEB systems vary in their functionality, most systems will provide a warning (audible and/or visual) to the driver. AEB systems will also intervene and brake the vehicle automatically if the driver does not respond.  Some systems will also charge the brakes in order to provide the most efficient braking and prepare the vehicle for collision by pre-tensioning the seatbelts.

Some AEB systems deactivate if they detect avoidance action being taken by the driver.

Crash avoidance systems can be classified into three main categories:

  • Low Speed system – this version targets city driving where crashes often occur at low speeds but can cause debilitating injury such as whiplash injuries.  Typically, these systems look for the reflectivity of other vehicles and are not as sensitive to pedestrians or roadside objects.
  • Higher Speed system – this version typically utilises long range radar to scan further ahead of the vehicle (up to 200 metres) at higher speeds.
  • Pedestrians – these versions use a camera combined with radar to detect vulnerable road users through their shape and characteristics. The way in which pedestrians move relative to the path of the vehicle is calculated to determine whether they are in danger of being struck.

These three systems of AEB are not mutually exclusive and there are vehicles that may have two or more versions. It is important to note that within each type of system there will also be variation in functionality depending on the manufacturer and even car model (in terms of warnings, braking function, time-to-collision etc.,).

TAC Auto Emergency Braking TV ad

Where can I get AEB?

Many manufacturers in Australia now have some form of AEB included on some of their vehicles as standard or an option.  

Use the search tool on this site to find cars with Auto Emergency Braking

AEB must be fitted to the vehicle at the time of purchase; AEB cannot be retrofitted to a car.

Why should I get AEB?

The effectiveness of AEB has been investigated in a number of studies and a range of effectiveness was found. But the overall trend is a reduced number of crashes for vehicles equipped with AEB. There is limited real world performance data available for AEB at the current time, particularly in Victoria and Australia. Of the real world data available (Schittenhelm, 2013), the results indicate that:

  • 53% of all rear end collisions could be mitigated in crash severity
  • 35% of rear end crashes could be avoided completely

In addition, an Australian AEB simulation project estimates that AEB has the potential to reduce fatal crashes by 20-25% and injury crashes by 25-35% (Anderson, Doecke, Mackenzie & Ponte, 2013). Research utilising insurance claims data have also found that forward collision avoidance systems, especially those that brake autonomously, showed the biggest claim reductions of 10-14% (Moore & Zuby, 2013).

Alternative names for AEB

  • Pre Sense Plus (Audi)
  • Driving Assistant Plus (BMW)
  • Active City Stop (Ford)
  • Collision Mitigation Braking System (Honda)
  • Pre-collision Safety System with Brake Assist (Lexus)
  • Smart City Brake Support (Mazda)
  • PRE-SAFE Brake (Mercedes-Benz)
  • City Collision Mitigation (Mini)
  • Forward Collision Mitigation (Mitsubishi)
  • Pre-Collision Braking System (Eyesight) (Subaru)
  • Pre-Crash Safety System (Toyota)
  • City Emergency Braking (Volkswagen)
  • City Safety (Volvo)


Does it work on different roads?

Yes, however, depending on the condition of the road, stopping distances may vary.

Will AEB work in all weather conditions?

AEB should work under most conditions however wet roads may increase stopping distances and fog, or sun glare may impact on the technology's ability to detect hazards. It is important to remember that the driver always has responsibility for the vehicle and that they should drive to the conditions.

Does AEB work if you are reversing?

AEB is designed to avoid frontal crashes and will not brake for you if you are reversing. There are other technologies available to help you avoid a reverse crash, such as, reversing sensors and reverse cameras, however these technologies will not brake the vehicle for you.

What speeds does AEB work at?

The systems vary by manufacturer so check with your dealer or in the user manual for specific details.

What can the system detect? People, animals, objects etc?

Depending on the type ofAEB, the system can detect cars, objects and/or pedestrians. However, system functionality varies by manufacturer so we encourage you to ask your dealer or check the user manual.

Does AEB work when towing?

Yes, however stopping distances may increase so AEB may not be able to avoid the crash but it should still reduce the speed of impact.

Can you switch off AEB?

AEB systems vary by manufacturer but usually AEB can be switched off. Check with your dealer or the user manual.

Can I get AEB installed after I've bought it?

AEB cannot be retrofitted so ensure that the vehicle you are purchasing has it as standard or make sure you order it as an option at the time of purchase.

How much does AEB cost?

Cost will vary by manufacturer, check directly with your dealer or via the manufacturers website.

What is the warranty on AEB systems?

This will vary by manufacturer, please check with your dealer.

Is Emergency Brake Assist the same as AEB?

No. AEB often works with other technologies in the car in order for the vehicle to respond to an emergency situation as efficiently as possible. Emergency Brake Assist specifically works to increase the braking pressure in order to assist the driver to stop the car as quickly as possible. Emergency Brake Assist does not detect hazards so it relies on the driver to detect the hazard and respond. Many AEB systems will work with Emergency Brake Assist technologies to detect the hazard and apply maximum braking force.

Is Adaptive Cruise Control the same as AEB?

No. Adaptive Cruise Control (ACC) is similar to both AEB and Cruise Control. ACC works like cruise control however it detects the speed and distance of the vehicle in front and maintains an appropriate following distance. ACC requires the driver to set the desired travelling speed and will accelerate or decelerate up to that speed depending on the vehicle in front. AEB is always scanning (unless turned off by the driver) and only comes into action in emergency situations.

Vehicles and vehicle technologies keep us safer on the road by ensuring that we drive in a safe manner, by helping us avoid a crash and by protecting us if a crash does happen.
Find out why safer vehicles are part of the Towards Zero vision.