Roanoke Times
Copyright (c) 1995, Landmark Communications, Inc.
DATE: THURSDAY, January 27, 1994 TAG: 9401270230
SECTION: NATIONAL/INTERNATIONAL PAGE: A1 EDITION: METRO
SOURCE: Knight-Ridder/Tribune
DATELINE: WASHINGTON LENGTH: Medium
\ Anti-lock brakes, long touted as an important safety feature, don't necessarily cut the frequency and cost of passenger car accidents, a surprising new study shows.
The Highway Loss Data Institute, the insurance industry research group that conducted the study, still believes drivers should get anti-lock brakes on their cars, and government safety officials and automakers immediately said more studies are needed.
But the new study is likely to ignite a debate over the relative importance of devices so popular that they are installed in about 10 million vehicles nationwide.
The device senses when a vehicle's wheels are about to lock up and then presses and releases the brakes, over and over very quickly, to prevent lock-up. In effect, anti-lock systems pump the brakes, just as drivers are taught to do in skids, but they do it much faster - many times a second. When they are engaged, in fact, anti-lock brakes pedals can actually make a loud chattering noise.
For years, insurers, automakers and safety groups promoted the feature, known as ABS (anti-lock braking systems), after experiments on test tracks showed that they could reduce skidding and spin-outs during emergency braking.
But institute officials say their study of about 95,000 insurance claims showed little or no difference in claim rates or amounts for 1991 cars without anti-lock brakes compared to the same model 1992 vehicles with the brakes.
"The study shows that these are not some silver-bullet brakes that are going to prevent all kinds of crashes," said institute President Brian O'Neill. "I think there is a perception out there that anti-lock brakes are going to allow you to stop on a dime in any crash situation. That is not true."
While automakers and government auto safety officials did not directly challenge the new study, they said it's too early to draw any conclusions about anti-lock systems and urged consumers to continue to use and buy them until more studies can be conducted.
"I'm just saying there isn't enough data yet," said Barry Felrice, associate administrator for the National Highway Traffic Safety Administration.
Added Jay Minotas, manager of insurance industry relations for General Motors Corp., the nation's largest seller of ABS cars: "Our concern is that a bad message not get out there about ABS" from the insurance study. "There are a lot of benefits to ABS, and we know they're there."
It's possible that drivers, not anti-lock brake systems, may be partly responsible for the findings of the study. Some earlier studies suggest that drivers can become more assertive when they have anti-lock brakes and that some drivers don't understand how they work.
For instance, surveys in North Carolina and Wisconsin found that a significant number of drivers thought they had to pump their anti-lock brakes to engage them. Actually, pumping might prevent the brakes from activating; they need firm and constant pressure and pump themselves.
Felrice said the government noticed the same problem when the brakes were installed in police cars.
by CNB