Anti-lock brakes - how they work

It’s only natural; in a panic situation you jump on the brakes, lock the wheels and skid out of control. But not if you’ve got an anti-lock braking system (ABS), which sense when a wheel is about to lock up, then back off the brakes for you.

Even if you keep that middle pedal planted to the floor, the electronic gizmo responsible will release the brakes for you, then as soon as the braking is reduced the system builds up the pressure again, taking the wheel back to the point of locking once more. 

Anti-lock brakes don’t reduce your stopping distance – they only prevent you from locking the wheels and losing control

It does this 50 times each second; reckon you could compete with that? It’s all down to sensors at each wheel, which work out when a tyre is losing its grip and starting to lock up.

As soon as a loss of traction is detected, the brakes are momentarily released, before being reapplied to keep the wheel on the point of locking, but not actually allowing a skid to develop.

This way, maximum braking power is always being applied, but the wheels aren’t allowed to lock – ensuring you don’t lose your steering because of locked wheels. The key thing though is that anti-lock brakes don’t necessarily reduce your stopping distance – but they do prevent you from locking the wheels and losing control.

So don’t be tempted to sit closer to the car in front, or brake later, just because your car has ABS.