An anti-lock braking system (ABS) is a type of automobile brake that is designed to not lock up in emergency stopping situations. Originally offered only on luxury and high performance vehicles, ABS brakes are becoming standard equipment on many new cars and trucks.
ABS systems work by monitoring the rate that the wheels are turning. When the system detects one wheel that is decelerating more quickly than the other wheels, or decelerating at a preset rate that indicates it is about to lock up, the ABS system reduces the brake pressure to that wheel.
When wheels lock up, they begin to slide. As the wheel slides it moves more quickly than a wheel that is being slowed while maintaining traction. ABS braking systems keep brakes from locking up by reducing pressure to wheels that are about to lock. On a car without ABS, a driver must manually apply the needed pressure to not lock up the wheels.
When an emergency situation occurs, many drivers naturally stomp the brakes and lock up the wheels, but this will not occur with ABS brakes. Instead, a driver can simply depress the pedal and the ABS system will work to assure that the wheels do not lock.
