Question Topic: Safety margins
The official DVSA guide to driving states:
Many cars either have an anti-lock braking system (ABS) fitted or have it available as an option.
If ABS is fitted it activates automatically. It prevents the wheels from locking, so that you can continue to steer the vehicle while braking. You should refer to the vehicle handbook for details of the manufacturer’s recommended method of use.
ABS is only a driver aid; it doesn’t help the vehicle to stop more quickly. Nor does it remove the need for good driving practices such as anticipating events and assessing road conditions. You still need to plan well ahead and brake smoothly and progressively.