An anti-lock braking system (ABS) is a safety system on motor vehicles which prevents the wheels from locking while braking.
The Anti-lock Braking System is designed to maintain vehicle control, directional stability and optimum deceleration under severe braking conditions on most road surfaces
It does so by monitoring the rotational speed of each wheel and controlling the brake line pressure to each wheel during braking. This prevents the wheels from locking up.
A rotating road wheel allows the driver to maintain steering control under heavy braking
Theory
When the car brakes (normally ) wheels exert a forward force on the street with less than maximum static sliding friction.
If the driver brakes very hard it can occur that the maximum static friction is surpassed and the wheels lose their grip and begin sliding
The amount of traction which can be obtained for an auto tire is determined by the coefficient of static friction between the tire and the road. If the wheel is locked and sliding, the force of friction is determined by the coefficient of kinetic friction. A tire that is just on the verge of slipping produces more friction with respect to the road than one which is locked and skidding . So locked wheels are less effective in stopping on a road.
But in gravel, sand and deep snow, locked wheels dig in and stop the vehicle more quickly. A locked tire allows a small wedge of snow to build up ahead of it which allows it to stop in a somewhat shorter distance than a rolling tire.
When tire does not slip, it will roll only in the direction it turns. But once it skids, regardless of the angle of the front wheels, the vehicle continues to skid in whatever direction its momentum sends it until either the driver releases the brakes
Basic Operation
The Anti-lock Braking System is designed to maintain vehicle control, directional stability and optimum deceleration under severe braking conditions on most