What is AEB?

Most manufacturers use this type of system, and it can save your life - but what is AEB?

Murray Scullion
Mar 12, 2018

AEB (Autonomous Emergency Braking) is a system that brakes the car for you in an emergency. To further explain this, it’s best if we break that down into three sections.

Autonomous - the system acts without the input of the driver.
Emergency - it will only intervene when it deems that you’re on course for a crash.
Braking - the system will apply the brakes.

Safest cars on sale according to Euro NCAP:

Volvo XC60

VW Arteon

Volvo V90

Volvo S90

Subaru XV

Why buy a car with AEB?

AEB can act as a safety net in an emergency. You might think that you’ll never need it, but there are often factors outside of your control that can affect your judgement. The car manufacturers site poor visibility and even glare from sunshine as a major reason for the take-up of AEB systems in their cars.

Of course, AEB systems are not full-proof, and no car makers are saying that it will stop all accidents. But it has been scientifically proven to is assist in avoiding accidents, as well as reducing the severity of them.

How does AEB work?

Although ‘autonomous’ may remind older readers of Knight Rider’s KITT, AEB systems use a selection of devices to essentially ‘read’ the road ahead. Most use a radar system teamed with a front facing camera, usually attached to the nose of a car.

From behind the wheel, generally, the first sign of the system working will be an on-screen prompt via the dashboard, alerting you to the fact that it thinks you’re about to have a crash. If you don’t use the brakes or use the steering wheel, the car will apply its brakes.

Braking power and ferocity varies from manufacturer to manufacturer, and some of them will deactivate once you use the brakes.

Obviously manufacturers, along with safety experts, do not recommend using AEB instead of your own right foot. AEB doesn’t kick in until the very last moment, and it’s a strong and harsh system that you wouldn’t want to use every day.

At what speed does AEB work?

In general, the more expensive systems work up to a higher speed than cheaper systems. Most accidents occur in city driving at around 12-15mph and most AEB systems work at up to 25mph, but some work at motorway speeds too.

AEB Safety testing

Euro NCAP is a safety assessment program that every new car in Europe has to be put through. It awards cars on a star-based system. Five for the safest, zero for the least safe.

Not only do AEB systems make a car safer for the occupants, but it’s proven to make them much safer for pedestrians. Pedestrians and cyclists account for 30 per cent of all fatalities in the EU every year. Because of this, pedestrian and cyclist safety is a growing concern for Euro NCAP.

One of the criterias on which new cars are assessed is a pedestrian test. This is designed to check how well pedestrian-detection systems work. The tests represent common situations that cause pedestrian casualties. In these simulations, generally, when an AEB system is used, accidents that would normally result in a fatal collision can be avoided.

AEB benefits

It’s a life-saving piece of technology, and a safety net for a situation that might leave you momentarily distracted behind the wheel. Generally, it makes cars safer. Better for you, and better for pedestrians. But it also makes insurance cheaper. A recent study by Thatcham Research found that cars fitted with AEB systems were £80 a year cheaper to insure than the same car without the system. The savings can be even more for younger and less experienced drivers.

AEB drawbacks

Obviously, the safety benefits far outweigh the drawbacks of such systems. However, if you’re the type of person that doesn’t like electronic systems interfering with your driving, AEB might irk you.

Each manufacturer's system works differently, and some don’t like you getting too close to the car in front during motorway driving. Cheaper systems can get confused between pedestrians and other cars in traffic.

I can’t find a car with AEB?

AEB is a catchall term for the system. Manufacturers use different variations for their own specific systems.

BMW - BMW Pedestrian Warning With City Brake Activation
Fiat - Fiat City Brake Control
Mitsubishi - Mitsubishi Forward Collision Mitigation
Skoda - Skoda Front Assistant
Audi - Audi Pre Sense Front & Audi Pre Sense Front Plus
Volkswagen - Volkswagen Front Assist
Ford - Ford Active City Stop
Mercedes-Benz- Mercedes-Benz Collision Prevention Assist
Honda - Honda Collision Mitigation Brake System
Volvo - Volvo City Safety

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