The Insurance Institute for Highway Safety launched headlight ratings last spring after finding that government standards based on laboratory tests allow for huge variation in the amount of illumination headlights provide in on-road driving. Nighttime visibility is critical to highway safety because about half of traffic deaths occur either in the dark or at dawn or dusk.

Engineers measured how far light is projected from a vehicle’s low beams and high beams as the vehicle travels straight and on curves. Glare from low beams for an oncoming driver was also measured. Vehicles equipped with high-beam assist, which automatically switches between high beams and low beams depending on the presence of other vehicles, can get extra credit.

IIHS evaluations show that a vehicle’s price tag doesn’t correspond to the quality of headlights. More modern lighting types, including high-intensity discharge (HID) and LED lamps, and curve-adaptive systems, which swivel in the direction of steering, also are no guarantee of good performance.

A recent issue of AARP magazine quoted IIHS headlight expert Matt Brumbelow that “only 18 percent of drivers use their high beams, even when no other vehicles are around”. A “Did You Know” article in May, 2016, dealt directly with this problem. Thus, since apparently drivers don’t recognize the safety benefits of high beams over low beams, vehicles that automatically switch to high beams when there are no oncoming vehicles get a higher rating.

According to the IIHS, among 2017 models, only seven are available with good-rated headlights. They are the Chevrolet Volt small car, Honda Ridgeline pickup, Hyundai Elantra small car, Hyundai Santa Fe midsize SUV, Subaru Legacy midsize car, Toyota Prius v midsize car and Volvo XC60 midsize luxury SUV. In the Institute’s evaluations, engineers measure how far light is projected from a vehicle’s low beams and high beams as the vehicle travels straight and on curves. Glare from low beams for oncoming drivers is also measured.

“Our goal of promoting good visibility without excessive glare hasn’t changed,” says IIHS Senior Research Engineer Matthew Brumbelow. “However, we realized that some manufacturers were ‘playing it safe’ and aiming their headlights low to the detriment of visibility. Our new system does a better job of balancing glare and visibility.”

With the IIHS including headlights in their safety ratings, we should see overall improvement in nighttime driving. The next time you consider a new car purchase, check out how good the vehicle’s headlight system is rated by the IIHS – and, if you are among the 82 percent of drivers that do not use high beams, consider a vehicle with high-beam assist. It might be a safety feature worth the extra cost.

For more articles on traffic law and safety, go to the traffic safety board’s web site at: www.franklincony.org and click on “Traffic Safety Board” under departments then look for Did You Know articles under “services”. You may also email me at: dwerner151@verizon.net.