IIHS headlight ratings show big need for improvement

PEMBROKE PARK, Fla. – Drivers having trouble seeing the road at night might not have their eyesight to blame.

A study by the Insurance Institute for Highway Safety (IIHS) found recent advances in headlight technology, like LED and high-intensity discharge (HID) lamps, do not guarantee good performance.

"You don't have to pay for an expensive option to get good headlights," said David Zuby, chief research officer at IIHS. "The base model Honda Accord, for example, has some of the better-performing headlights in the bunch."

Researchers tested 31 vehicles with over 80 headlight systems combinations, taking into account visibility and glare on both low and high beams after dark. A special device measures the light as the vehicle drives in five different scenarios: traveling straight, a sharp left curve, a sharp right curve, a gradual left curve and a gradual right curve.

IIHS's first-ever headlight ratings revealed only one of its tested vehicles got a "good" rating: the Toyota Prius V with LED lights and high-beam assist.

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The other 30 vehicles tested received ratings anywhere from "acceptable" to "poor," with many of the poor-rated headlights belonging to luxury vehicles.

According to the study, of the 44 headlight systems earning a poor rating, the halogen lights on the BMW 3 series are the worst. Drivers with those headlights would have to be going 35 mph or slower to stop in time to avoid an obstacle in their lane.

A LED curve-adaptive system with high-beam assist, a combination that rates marginal, is the best available option for the same car.

"Government standards for headlights allow a wide range of illumination down the road," Zuby said. "Headlight systems are often designed as a styling statement, rather than to provide good light for drivers."

A study by AAA in 2015 also found big differences in performance from the most common headlight lamp. AAA's test results suggested halogen headlights, when compared with HID and LED headlights, might fail to safely light up dim roadways at speeds as low as 40 mph.

Halogen headlights can be found in more than 80 percent of vehicles on the road today.

"The differences are stark," Zuby said.

With about half of traffic deaths occurring either in the dark or in dawn or dusk conditions, improved headlights have the potential to greatly reduce traffic fatalities.

IIHS is encouraging automakers to improve headlight function and is also encouraging drivers to place a little more importance on the quality of their headlights.

"You probably don't think too much about your headlights, but good headlights that help drivers see well far down the road could prevent a lot of crashes," Zuby said.