Car headlights get on the level

If you're like many drivers, you probably have a beef with cars that feature high-intensity discharge (HID) headlights. Sure, HID headlights are great if your car has them-they light up the road like daylight-but their other-worldly blue glare can be tough on the eyes of drivers in oncoming cars. These lights are wildly unpopular with U.S. motorists, who have filed hundreds of complaints with the National Highway Traffic Safety Administration, according to spokesman Tim Hurd in Washington.

Valeo Sylvania (a joint venture of Osram Sylvania and Valeo) is combating the potentially blinding glare of its HID headlights with the recent introduction of automatic-leveling HID technology. Automatic leveling will speed the acceptance of HID headlights, which are currently found only on a few luxury auto models, because they automatically adjust themselves to the proper angle, according to Tony Garrison, systems engineering manager for Valeo Sylvania (Auburn Hills, MI).

"The automatic leveling technology always keeps the headlamps at the correct legal level so we don't impede the performance of oncoming drivers on the road," says Garrison. So, for example, if a car were laden down with three passengers in the backseat, the automatic leveling technology would automatically adjust the headlights downward so they would not shine directly into an oncoming driver's eyes. Valeo holds two U.S. patents on the technology.

HID light sources produce about three times the amount of light, or lumens, at a lower wattage than traditional lamps. They are also much more efficient: 91 lumens per watt vs. 22 lumens per watt for a comparable halogen light source. HID headlights do a much better job of illuminating the road than their counterparts. But what makes them so desirable for their drivers can also make them irritating to others on the road.

Although the National Highway Traffic Safety Administration does not collect highway crash statistics associated with headlight glare, Hurd says many drivers perceive standard HID headlights to be a hazard. The agency is seeking public comment on headlight glare issues (for more information, visit www.nhtsa.dot.gov). If automatic leveling succeeds in keeping the blue-white lights out of other drivers' eyes, it will be a boon to public safety, says Hurd, although other types of headlights, including fog lamps and SUV headlights, also garner complaints.

Valeo began offering automatic leveling on its HID systems in September and claims to be one of the first U.S. automotive suppliers to debut the technology, which is required for all HID systems in Europe. General Motors will be the first U.S. automaker to employ them as an option on the 2002 Cadillac Catera, according to Garrison. Another U.S. car maker will reportedly use the technology on some 2004 models (Garrison declined to specify which car manufacturer). For the foreseeable future, HID headlights-with or without automatic leveling-are likely to be found only on high-end car models, though Garrison believes this will change in the next three to five years.

Designing the automatic leveling systems was a challenge because each automaker has its own specifications that Valeo engineers had to work with. "You have to design these systems to the manufacturer's vehicle build. It's a joint effort between the car manufacturer and the component systems designer," says Garrison.

Valeo is working on other headlight innovations, including those that will feature automatic aiming, dimming, and range finding, according to Garrison.