The anti-lock braking system, or ABS, is designed to help you maintain some steering ability and avoid skidding while braking.
Introduced in 1980, it has become standard equipment on the majority of vehicles sold here in Canada.
ABS uses wheel speed sensors to determine if one or more wheels are locking up during braking. If a wheel starts to lock up, a series of hydraulic valves limit or reduce the braking on that wheel. This prevents skidding and allows you to maintain steering control.
ABS works differently than other braking systems. You must apply steady and constant pressure on the brake pedal until the vehicle is completely stopped. Do not take your foot off the brake, or "pump" the brakes.
ABS won't shorten your stopping distance. In fact, on gravel, slush, and snow, you should allow for a longer stopping distance. Your tires will effectively "float" on this surface, carrying your vehicle further along.
While ABS can significantly increase the control you have over your vehicle, it can't sense poor driving conditions, or compensate for bad judgment. It's your responsibility to drive at reasonable speeds for weather and traffic conditions. Always leave a margin of safety.