Autonomous Emergency Braking: what you need to know

Autonomous Emergency Braking: what you need to know
Technological advances in car manufacturing are not only leading to more eco-friendly vehicles, but also significantly safer ones.

Autonomous Emergency Braking (AEB) is one of the biggest safety breakthroughs yet – giving vehicles the capacity to slow themselves down when faced with a potential accident.

What is AEB?

It’s a safety system built into vehicles which monitors the traffic and road conditions ahead for signs a collision might occur.

AEB is able to warn a driver of an upcoming danger, applying the brakes if they don’t respond within due time.

With AEB applied the speed at which a collision occurs can be decreased to a life-saving degree, or ideally, impact is avoided altogether.

How does AEB work?

The way in which AEB technology reacts and operates differs by vehicle make and model, and at this stage, some systems are more sophisticated than others.

But they all work using the same principles.

AEB systems use Lidar (light detection and radar) or camera sensors, or a combination of both, to help prevent potential accidents.

Information gleaned via these elements – together with data on a vehicle’s travel speed and trajectory – helps the AEB system to decide whether a hazardous situation is developing.

When detecting a potentially critical situation most systems will first try to warn the driver that action is needed. If no driver action is taken and the AEB system judges a collision is expected, the brakes will be applied automatically.

READ MORE: Top 10 safety features modern cars should have as standard

How sudden is the braking impact?

Autonomous Emergency Braking

The AEB system will determine the necessary brake force needed to be applied.

This can vary between an elevated level, and full braking force – with the aim of reducing the speed at which a collision will take place.

Different AEB systems have different operating speed ranges and there are separate types of hazards they can identify. For example, some systems are more effective in low speed urban areas, while others are better equipped to handle rural or multi-lane driving.

While systems have different capabilities, the technology is constantly adapting and improving, heading towards an AEB system with the capacity to avoid collisions altogether.

Why is AEB so important?

Not only can it reduce the speed at which a collision happens, it has the potential to stop the crash happening in the first place.

A 2015 study by The European New Car Assessment Programme (Euro NCAP) and Australasian NCAP found that AEB led to a 38% reduction in real-world rear-end crashes.

Researchers at the University of Adelaide also found in a study of 104 crashes, AEB could have reduced fatal collisions by 20-25% and the likelihood of injury by 25–30%.

Where seatbelts and airbags are in place to protect passengers in the case of a crash, AEB aims to reduce the likelihood of a crash happening in the first place.

Thatcham – a research centre that specialises in vehicle safety – recently said AEB is “probably the most significant development in car safety since the seatbelt and could save an astonishing 1,100 lives and 122,860 casualties in the UK over the next 10 years.”

READ MORE: Euro NCAP launches automated technology timeline

Which cars are fitted with AEB?


Currently, just over a fifth (21%) of new vehicles come with AEB fitted as standard, with 27% offering systems as optional extras for an additional charge.

But Thatcham reports that around 70% of new cars aren’t yet being fitted with the system at all.

How much does AEB cost as an extra?

In some cases, where AEB is offered as an extra, it can be bundled together as a safety package costing up to an additional £1,300.

In others, a simple ‘city’ version of the system can cost as little as £200 extra.

Volvo was one of the first manufacturers to launch collision avoidance technology in 2006. Two years later the company made its City Safety AEB system standard on all new Volvo models.

Volvo has since reported its AEB system has reduced insurance claims for rear-end frontal collisions by 28%.

Will AEB be fitted as standard in the future?

Steps are now being taken to ensure AEB will become standard on all vehicles in the near future.

Euro NCAP will no longer give a five-star safety rating to any car without AEB so it’s pretty likely that it will be become a compulsory feature at some point.

The European Parliament also recently called for all new cars to be fitted with AEB as standard, with the Parliament Committee on Transport set to go before the European Commission in March 2018.

The committee will publish its findings on AEB, as well as other future safety requirements for vehicles within the EU and will call for AEB systems to be mandatory for all new vehicles.

Safety body Thatcham is also behind the European Parliament’s decision to make the “lifesaving technology” standard on all vehicles.

AEB has been a mandatory requirement on most newly registered Heavy Goods Vehicles over 7.5 tonnes since November 2015.

There are only a few types of HGV exempt from the requirement such as steel suspension or four axle lorries which, in theory, could affect the performance of AEB sensors.

READ MORE: New AI system to power self-driving cars

What else is AEB called?

Various names have been adopted by manufacturers which feature elements of AEB technology across their model range:

ManufacturerAEB name

Adaptive Cruise Control with Pre Sense Front

Pre-Sense Front

Pre Sense City


Driving Assistant

Driving Assistant Plus

Active Guard

CitroenActive City Brake

City Brake Control

Brake Control


Active City Stop

Pre Collision Assist

Active Braking


Collision Mitigation Braking System

City Brake Active System

HyundaiAutonomous Emergency Braking

Forward Collision Warning & Intelligent Brake Assist

(Safety Shield) Forward Collision Emergency Braking

Intelligent Cruise Control with Emergency Brake

(Dynamic Safety Shield) Forward Collision Warning & Intelligent Brake Assist

JaguarAutonomous Emergency Braking

Forward Collision Warning Plus

Forward Collision Plus

Land RoverAutonomous Emergency Braking

Pre Crash System

Adaptive Cruise Control System with Pre Crash Safety

MazdaSmart City Braking Support

Collision Prevention Assist 3.0

Distronic Plus

MiniDriving Assistant
MitsubishiForward Collision Mitigation
NissanForward Emergency Braking

Active City Brake

Emergency Collision Alert with Emergency Braking

PorscheAdaptive Cruise with Porsche Active Safe
Range Rover

Autonomous Emergency Braking

RenaultActive Emergency Braking

Adaptive Cruise Control with Front Assist

Safety Assist

Front Assist


City Safe Drive

Front Assist

SuzukiRadar Brake Support
TeslaAutomatic Emergency Braking

Pre-Crash System


Forward Collision Warning with Automatic Brake Intervention

Front Camera + Emergency Braking

Front Camera + Emergency Braking Adaptive Cruise and Stop Go


Front Assist Including City Emergency Braking

City Emergency Braking

What other car safety developments are on the horizon?

As well as continually advanced braking systems, many other aspects of car safety are becoming more autonomous.

Cadillac’s semi-autonomous-driving Super Cruise system, for example, uses the car’s existing driver assistance features like cruise control and adds in new Lidar-scanning and self-steering functions to avoid accidents.

The Lexus LS sedan and Volvo XC60 crossover SUV also offer a self-steering function which allows them to detect and avoid collisions in various circumstances.

Volvo’s City Safety system, for example, can detect and avoid pedestrians in its path at low-speeds.

Last year, the EURO NCAP issued a report stating that, in addition to AEB, it expects driver monitoring, automatic emergency steering, Vehicle to Vehicle Data Exchange and Vehicle to Infrastructure, to all be fitted as standard in new cars by 2024.

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