How should you use anti-lock brakes when you need to stop in an emergency?

ABS braking

An anti-lock braking system, often simply known as ABS braking, can stop your vehicle from skidding in the event of your wheels locking up when you depress the brake pedal.

It can reduce your stopping distance and allow you to retain a degree of steering.

ABS is triggered when it detects that one of your wheels has locked and begun to skid. It then pumps, or rapidly applies and releases, the brakes.

Rule 120 from the UK highway code states:

If your vehicle is fitted with anti-lock brakes, you should follow the advice given in the vehicle handbook. However, in the case of an emergency, apply the footbrake firmly; do not release the pressure until the vehicle has slowed to the desired speed. The ABS should ensure that steering control will be retained, but do not assume that a vehicle with ABS will stop in a shorter distance.

What is ABS and how does it work? – carwow.co.uk

Stopping distances made simple – rac.co.uk