Anti-lock Brakes (ABS) Slam on the brakes during an emergency and chances are your car will become a wild ride as it skids down the road, especially if it’s rain-slicked or icy. Locking up the wheels - or skidding - is dangerous not only because it increases the distance before the car stops, but also because the driver loses the ability to steer. An ABS system pumps the brakes automatically, many times a second, to prevent lockup and to help the driver maintain control. On dry pavement, ABS doesn’t substantially shorten stopping distances. But on wet or slippery surfaces, ABS can help a great deal - if a driver knows how to use it. Drivers are traditionally taught to pump the brakes on slippery roads to avoid a skid. But with ABS, firm and continuous pressure - not pumping - is required to activate the ABS feature.

Dos and don'ts of ABS. Like air bags, anti-lock brakes have had their share of controversy. Some studies have shown that vehicles equipped with ABS don’t have better safety records than those vehicles not equipped; indeed, some have shown their records to be worse. But safety officials suspect the problem is not with ABS itself but with drivers who don’t know how to use ABS correctly. To this end, the National Safety Council has the following recommendations:

Don't be alarmed by mechanical noises or pedal pulsations when applying ABS brakes. ABS is only activated under hard braking. Pulsations and noises are normal and indicate ABS is working correctly. Don’t pump the brakes in an effort to avoid locking up the wheels; ABS automatically pumps the brakes, and much faster than the driver ever could.

Don't forget to steer. The main advantage of ABS is that it prevents the wheels from locking up, which helps prevent the vehicle from going into an uncontrollable skid. Thus ABS allows you to maintain steering control during emergency braking - but only if you continue to steer.

Do keep your foot on the brake pedal. Maintain firm and continuous pressure on the brake pedal when braking, even when the pedal pulsates.

Do know the difference between four-wheel and two- or rear-wheel ABS. Most cars and many trucks have four-wheel ABS. But some light trucks have only rear-wheel ABS; with rear-wheel ABS, the front wheels can still lock up during hard braking. If this happens, you should ease up on the brake pedal with just enough pressure to allow the front wheels to roll again so that you can steer.

Do practice driving with ABS. Find an empty parking lot or open area and practice emergency stops so that you can become accustomed to the feel - the normal pulsations - of ABS when it activates.

Do allow enough distance to stop. ABS doesn’t necessarily allow you stop in a shorter distance; it primarily helps you to maintain directional control. Just because your car or truck is equipped with ABS doesn’t mean you can take more chances.