AEB stands for Autonomous Emergency Braking. It's the safety system that brakes the car automatically when a collision looks unavoidable and the driver hasn't reacted in time. Compulsory on new cars across the EU since July 2024 under the General Safety Regulation, and standard fitment on most UK-market cars from 2018 onwards.
AEB = Autonomous Emergency Braking. The system watches the road ahead, detects when a collision with a car, pedestrian, cyclist or animal is about to happen, warns the driver, and brakes the car itself when the driver doesn't react in time.
It's one of the most consequential features in modern car safety. Euro NCAP's real-world crash research (a 2015 study run with its Australasian counterpart ANCAP) found AEB-equipped cars in far fewer rear-end collisions than cars without it. The EU's General Safety Regulation made AEB compulsory: on new car types from July 2022 and on every new car registered from July 2024. UK showrooms get the same cars, so the fitment is standard here too.
Despite the name, AEB doesn't make decisions like a self-driving car. It's a single-purpose collision-avoidance feature operating in the background. The driver is still in control at all times. AEB only activates when it detects a high probability of an imminent crash that the driver isn't responding to.
AEB uses one or both of two sensor types, depending on the make and model.
Forward-facing camera. Usually mounted behind the windscreen near the rear-view mirror. The camera reads the road, identifies vehicles, pedestrians and cyclists, and calculates closing speed. Some systems use the camera alone for AEB. Camera-only AEB tends to work better in good visibility, less well at night or in heavy rain.
Front radar. Usually mounted behind the bumper, often hidden behind the manufacturer's grille badge (this is why a badge swap can knock the system out of alignment). Radar measures distance and closing speed directly, and works in conditions where the camera struggles. Many platforms pair the radar with the camera in a sensor-fusion setup.
Sensor fusion. When both camera and radar are present, the AEB system cross-checks each input against the other before triggering. This is why fusion-based AEB is less prone to false braking than camera-only or radar-only systems.
When the system calculates that a collision is unavoidable and the driver hasn't braked, it does three things in sequence: audible warning, pre-conditioning of the brake system (pads moved against the disc, brake assist primed), and full braking application if the driver still doesn't respond. On some cars the seatbelts pre-tension as part of the same sequence.
The same triggers as any forward-mounted ADAS sensor. AEB depends on both the windscreen camera and the front radar being correctly aimed, so anything that disturbs either will throw the system out of tolerance.
The common triggers in our network:
Yes. AEB (Autonomous Emergency Braking) and Automatic Emergency Braking refer to the same system. Different sources use different expansions of the acronym. Manufacturers also use their own brand names (Front Assist on VW, Pre-Sense on Audi, Honda Sensing, Toyota Safety Sense Pre-Collision) for the same underlying feature.
Across the EU, yes: the General Safety Regulation required AEB on new car types from July 2022 and on every new car registered from July 2024, and that rule applies directly in Northern Ireland. Great Britain runs its own type-approval scheme, but cars for this market are built to the identical spec, so a new car bought in the UK today has AEB fitted. Older cars carry it voluntarily; most new models since 2018 do, and nothing requires it to be retrofitted.
On most cars yes, through the settings menu, though the system switches itself back on at the next ignition cycle: the regulation that mandates AEB requires that default. Turning it off doesn't break any law for now, but you lose the collision-avoidance function until it's back on, and a system that keeps false-triggering is better fixed than muted.
Phantom braking is usually a reference problem: the forward camera or radar is working from out-of-tolerance data after a windscreen swap, bumper repair or sensor disturbance, and reads shadows, road markings or a low bridge as an obstacle. Recalibration of the sensor at fault normally settles it. Honda Sensing behind aftermarket glass and the Hyundai Tucson are the two patterns we see most often in our work. Front camera or front radar calibration costs £162 inc VAT (£135 +VAT) per system; where the sensor itself has been replaced, coding it to the car is billed as its own line alongside.
Most AEB systems are tuned for full collision avoidance at town speeds and for collision mitigation, cutting the impact speed rather than avoiding the crash outright, at higher speeds. Where those bands sit depends on the car and on the type of obstacle (vehicle, pedestrian, cyclist), and the handbook for your model gives the exact thresholds.
If the AEB warning hasn't cleared after a windscreen swap, bumper repair or accident, head to the homepage form. We come back with a price for each system, camera and radar itemised, and the service centre covering your postcode.