The antilock brake system (ABS) was introduced by car manufacturers in the 1980s. Immediately, it was hailed as a major safety feature because of its ability to help drivers avoid crashes that result from skidding on wet roads. Today, the brakes are standard equipment on most new vehicles – but at a cost of over $1,000. Which leads you to ask if you are getting your money’s worth. Maybe not. When antilock brakes are needed the most – during emergency stops – many drivers do not use them correctly.
Antilock brakes are activated when the system senses that one or more wheels are about to lock up – usually, as you apply firm and continuous pressure to the brake pedal. If your car has ABS, you should not pump your brakes when stopping suddenly.
Pumping antilock brakes is a dangerous proposition because it deactivates the very technology you want to engage. Unlike regular braking systems, antilock brakes will not lock up the wheels or cause the car to skid out of control when you slam on them. That’s because the system reduces brake pressure and pumps the brakes automatically (up to 15 times a second) until the wheels rotate correctly. This maximizes road grip, prevents skidding, enables you to steer while braking, and may allow you to stop more quickly.
But do antilock brakes really reduce crashes? Although antilock brakes continue to work very effectively on the test track, they’ve produced mixed results on the road. U.S. government and insurance-industry studies found that they don’t significantly reduce crashes. Even more alarming are two surveys that concluded that cars with ABS are more likely to be involved in fatal single-vehicle crashes. Auto-industry studies, on the other hand, showed that ABS reduced accidents on wet roads by up to 19 percent – and that they prevented nonfatal crashes but not fatal ones.
Some experts put the blame on drivers for these inconsistencies. While ABS engaged, a driver may hear grinding sounds, feel the vibration from the brake pedal (both of which are normal), and then ease up, deactivating the system. Other drivers may feel overconfident with antilock brakes because they mistakenly believe that they can stop safely at any time.
The bottom line is: ABS makes little difference on dry roads and will actually lengthen stopping distances on gravel or soft snow. It is, however, effective in wet conditions.
Consumer and traffic-safety groups endorse antilock brakes, provided they are used correctly. To practice, take your car to an empty parking lot or other safe, open space on a wet day and drive up to 30 miles (50 kilometers) per hour. Slam on the brakes and maintain the pressure until you stop or can make a turn under control.
One final caution: Despite their safety benefits, experts say that antilock brakes don’t enable you to drive more aggressively or negotiate curves faster. Nor do they shorten the recommended distance you should maintain between your car and the one in front of you.