WASHINGTON - General Motors vehicles equipped with daytime running lights are in about 5 percent fewer U.S. collisions than comparable cars and trucks without the lights, according to a GM study.
The finding, based on preliminary data, suggests the lights are less effective in the United States than they are in Canada or Scandinavia but still valuable safety devices, said Robert Lange, GM's director of safety engineering. 'We think it is a great success story. A 5 percent reduction in collision events is a big, big reduction,' Lange said.
GM is touting the finding both to prove that it was right to begin installing the on-all-the-time lights on its full fleet in 1996 and to influence federal regulators.
Since mid-1998 the National Highway Traffic Safety Administration has been considering new rules to sharply limit brightness of the lights.
The rule-making generated hundreds of comments, many of them from motorists who find daytime running lights irritating and some from people who want to ban them.
GM, acknowledging that early complaints about glare were justified, has put daytime running lights in parking lamps, rather than headlights, on some redesigned vehicles, but the company still expects NHTSA to adopt new regulations.
Current federal rules permit daytime running lights but do not require them. They are standard on most Volvos, Saabs and Volks-wagens, as well as GM vehicles, and they are available on a smattering of models from at least five other manufacturers.
Lange said daytime running lights reduce collisions by as much as 15 percent in Scandinavia and Canada, where they are required. He said the lights apparently are more successful in regions closer to the earth's poles because of longer twilight there.
James Walker, president of JCW Consulting of Ann Arbor, Mich., and a critic of daytime running lights, said he's concerned about the validity of data from a manufacturer that wants to retain cheaper high-beam headlight-based daytime running lights.
At the same time, he said, the insurance industry has collected some hard-to-explain data showing higher injury rates among owners of certain daytime-running-lights-equipped vehicles.
Said Walker: 'There is some evidence that there can be negatives.'