Designed to prevent wheels from locking up or skidding, anti-lock brake systems feature sensors that detect the impending lockup of the brakes. At that point, the system applies pulsing braking power to the designated wheel or wheels, enabling them to continue rotating. This allows the driver to retain steering control while slowing or stopping the vehicle quickly.
Pros
Helps the driver maintain control of the car while braking on slippery or uneven road surfaces.
Cons
Added expense. Leads drivers to think the laws of physics no longer apply to them.