Automatic emergency braking (AEB)

Automatic emergency braking is the only system on this page you do not choose. It intervenes whether you want it to or not, and if it has to, you were already too late.

How does it work?

Radar and camera continuously estimate whether a collision with the car, cyclist or pedestrian ahead is imminent. Once the risk is high enough, the system first warns with a sound and a light. If you do not react, it brakes by itself sometimes fully, sometimes just enough to soften the impact.

AEB has been mandatory on all new cars placed on the EU market since 7 July 2024, alongside intelligent speed assistance. It is an emergency system: the Rijprocedure B states explicitly that you can deliberately let assistance systems inform or support you, with the exception of emergency systems.

What the CBR asks about this

• You understand that emergency braking is not a substitute for braking in time yourself. If it had to intervene, you did not anticipate well enough.
• You keep monitoring the traffic situation yourself. Emergency braking only looks at what threatens straight ahead.
• You keep radar and camera clean and unobstructed, because a covered sensor cannot intervene.

This system falls under these guidelines from the Rijprocedure B:

Limitations: This is where the exam questions are

It is a last resort

AEB is designed to limit the consequences of a crash, not to do your normal braking. Adapting your driving because the car will brake anyway is negative behavioural adaptation.

Limited speed range

Many systems only work within a certain speed window. At high speed the system can often only soften the collision, not prevent it.

Vulnerable road users and side impacts

Pedestrians and cyclists are detected less reliably than cars, especially in the dark or from the side. Crossing traffic is often not seen at all.

False alarms happen too

A bridge, a bend with a crash barrier or a sign above the road can trigger an unwarranted warning or braking action. You are still the driver then as well.

Three practice questions

Open one for the answer and the explanation.

Your automatic emergency braking intervenes because you brake too late for a queue. What does that say about your driving?

• That you anticipated too late; emergency braking is a last resort
• Nothing, that is what the system is for
• That the system is calibrated wrongly
• That liability lies with the manufacturer

Correct answer: That you anticipated too late; emergency braking is a last resort

Explanation: The driver stays responsible for performing the driving task. If AEB has to intervene, you should have braked earlier yourself.

Can you choose not to be supported by automatic emergency braking?

• No, it is an emergency system and intervenes independently
• Yes, you choose per trip whether to use it
• Yes, but only on the motorway
• No, because it only works below 30 km/h

Correct answer: No, it is an emergency system and intervenes independently

Explanation: The Rijprocedure B says you can deliberately let systems inform or support you, with the exception of emergency systems. Those you do not choose.

Why can automatic emergency braking often not prevent a high-speed collision?

• Because the system works within a limited speed range and can then only soften the impact
• Because it switches off automatically above 80 km/h
• Because the radar sees nothing above 100 km/h
• Because it only detects pedestrians

Correct answer: Because the system works within a limited speed range and can then only soften the impact

Explanation: The higher the speed, the longer the braking distance. Outside its design range AEB limits damage at best.

Written on the basis of the official CBR Rijprocedure B. These are not real exam questions.