American Woman Motorscene

Technically Speaking--Take A Break

by: Jayne O'Donnell

Recent studies have reported some rather shocking news: antilock brake systems may be contributing to as many accidents as they're preventing. And while safety investigators are looking into possible problems with different technologies, most evidence points to drivers who don't know how to use ABS. It's time to brush up on braking.

The most recent study by the National Highway Traffic Safety Administration (NHTSA) showed a 24 percent drop in fatal two-car collisions with ABS-equipped cars. And pedestrians and bicyclist fatalities caused by cars with ABS were down 27 percent. But deaths in single-car run-off-the-road crashes were up 28 percent.

"I think the jury is still out on ABS," said NHTSA chief Dr. Ricardo Martinez. General Motors safety spokesman Jay Minotas defended the system that's now on about 15 million cars or 12 percent of the cars on the road today. "It's not a cure-all," Minotas admits. GM complains that ABS prevents accidents and studies can't show "crashes that don't count."

Automakers have hailed anti-lock braking systems as the most significant crash-avoidance advance in automotive history. Yet these same car companies admit few people know how ABS works or what results they achieve. More important, even fewer people have any idea how they are supposed to react when the braking system is activated.

"Some people oversell what antilock brakes can do," says Doc Whitworth, General Motors' former manager of driver training. "Anti-lock brakes won't always stop sooner or longer, but they will stop you in control."

Here's how they do it: Computerized ABS keeps the vehicle's wheels rotating as the brakes are applied. Sensors monitor how fast the wheels rotate and feed the data continuously to a computer in the vehicle. Then the computer controls how much the wheels spin by repeatedly releasing and applying pressure to the brakes. This allows the wheels to keep rolling while the driver maintains both steering ability and a better braking force on most surfaces.

In order to allow ABS to work properly, drivers must maintain pressure on the brakes. The most frequent mistake people make with ABS is to take their foot off the pedal altogether or to pump the brakes when the system is activated.

That's because the vibration or noise that occurs when the system is activated can be startling. But it's little surprise that people react this way- we've all been taught to pump the brakes in panic situations.

"With panic braking, the tire won't let you get the corner back," says Whitworth. "Anti-lock brakes will stay activated for two or three miles."

Whitworth is well-versed in the marketplace misconceptions about ABS. Before his recent retirement, Whitworth traveled the country teaching everyone from the state police to the national press about the right and wrong way to work anti-lock brakes. And he saw his share of improper pedal pushing from all types of drivers.

ABS may provide for shorter stopping distances than would be attained without ABS. But the amount of improvement depends on several factors, which include the road surface, the severity of braking and the initial vehicle speed. More important, however, ABS improves vehicle steerability and stability during braking. On some surfaces, such as gravel roads, braking distances may in fact be longer, but the benefits of control will still be realized.

Following are some other important points to remember about ABS:

• Although some companies advertise ABS retrofits, none are believed to be effective. ABS is tailored to specific vehicles for optimum performance.
• If a car's ABS becomes inactive, the driver would be alerted through the car's dashboard display unit. The car should be taken in for repairs as soon as possible.
• Drivers should consult their owner's manual before changing tire size. Use of tires other than the original equipment can affect ABS performance.
• There's often an economic benefit to ABS, as well. Although a recent insurance industry report downplayed the accident prevention capabilities of ABS, many auto insurance companies still give ABS discounts ranging from five to 10 percent. New developments have made the systems affordable enough for economy cars, while luxury cars are getting highly refined systems.

Most car companies, import and domestic, are phasing ABS into their car lineups.

"ABS isn't a panacea for all problems," says Whitworth. "But you will stay in control of your vehicle.".

Also see: Technically Speaking---Dealerspeak: What You Need To Know, by Jayne O'Donnell