Autonomous Emergency Braking Explained

Autonomous Emergency Braking Explained

Discover how the life-saving car safety feature works

In the car manufacturing world, safety technology is fast advancing, and one of the most groundbreaking features to make driving safer in recent years is autonomous emergency braking. First fitted as standard on a Volvo back in 2014, it’s since earned high praise from safety experts Thatcham, who suggest that it’s now as important as wearing a seatbelt. 

As a function that has been proven to be lifesaving, it’s now considered so useful on the roads that it’s impossible for a car to earn the coveted 5 stars from car safety body Euro NCAP without it. 

What is autonomous emergency braking? 

By using technology both inside and outside the car that constantly monitors the space in front of it, it can detect an impending collision with another vehicle and, in many cases, cyclists and pedestrians too. It can react quicker than a driver could, applying the car’s brakes on their behalf and lessening the impact, if not avoiding a crash altogether. 

How does AEB work? 

In most cases, autonomous emergency braking uses sensors or radar technology to monitor the road ahead, warning the driver via a light on the dashboard or alarm within the car when it detects a hazard. If the appropriate action isn’t taken by the driver quickly enough, the brakes will automatically be applied. 

There are four main types of autonomous emergency braking systems, working as follows: 


Using light detection, Lidar sensors operate at low speeds to work out how far away the car in front is. Collisions at up to 15 mph can be prevented, and those that happen at speeds of up to 25 mph can have the impact vastly reduced. 


Using radio waves, radar-based sensors can prevent collisions with other vehicles (both moving and stationary) at up to 30mph. 


By essentially giving your car eyes of its own, camera-based autonomous emergency braking systems can see cars, pedestrians and cyclists, giving you the best chance of avoiding a collision with them.

Radar and camera combinations

The ultimate safety double act, autonomous emergency braking systems with both radars and cameras installed can sense hazards at close range as well as those further away. 

What else should you know about autonomous emergency braking? 

  • Autonomous emergency braking systems can go by different names depending on the car manufacturer. For example, Mazda calls it ‘Smart City Brake Support’, Volkswagen has named it ‘City Emergency Braking’, and Volvo refers to it simply as ‘City Safety’. 

  • It comes on many cars as standard, so it’s worth asking your new or used car dealer if it’s fitted on the model you’re interested in 

  • Autonomous emergency braking is no reason for complacency. Your full attention and razor-sharp reactions are still vital whilst travelling at any speed, from around supermarket car parks, to the cut and thrust of the motorway. 

Ask us about autonomous emergency braking at Carlingo 

Autonomous emergency braking is a feature that we’re proud to say is fitted on many models that we have on display here at Carlingo

Many used car buyers will naturally be interested to know what safety features their potential new model has to offer them, so do ask our team about autonomous emergency braking while you’re shopping with us; we’ll be only too happy to help. 

For more information about common car safety lingo, check out this article