Better Headlights are Critical for Nighttime Roadway Safety

June 27, 2016

The Insurance Institute for Highway Safety (IIHS) recently conducted its first-ever evaluation of headlight performance.  Government standards allow a wide range of illumination available to the consumer, so the IIHS tested 31 midsized vehicles with available headlight options for a total of 82 vehicle and headlight combinations.

Watch out for wildlife! Do your headlights measure up?

The IIHS study measured illumination with high beams and low beams on a test track including straightaways, various curved sections, and roadway obstacles.  Only one of the 82 combinations tested – the Toyota Prius v with LED headlights and high beam assist – earned a good rating. About one-third of the midsized cars tested can earn an acceptable rating by upgrading the headlights to the best available on the market, but another one-third cannot be purchased with headlights that rate higher than poor. This could be because some headlights are designed with aesthetics in mind, not illumination.

Headlights are a vital factor in roadway safety. About half of fatalities occur during the night or when lighting is dim such as at dawn or dusk. Better illumination does not correlate to a higher priced vehicle. For example, the IIHS study showed the best available headlights for the Toyota Prius v (rated “good”) illuminate roadway obstacles on the test track much better than the best available headlights for the BMW 3 series (rated “marginal”). Better illumination from headlights allows drivers more time to react and longer braking distances to avoid hitting obstacles in the roadway. Improved headlights could reduce nighttime fatalities by preventing drivers from hitting roadway obstacles such as deer or pedestrians, or from veering off the road by better illuminating curves in the roadway.

The news release from IIHS and a video with additional information on the recent study can be viewed here.

Currently, there is not a great recommendation to consumers for the best possible headlight illumination. Future studies from IIHS should drive the need to improve headlight design to focus primarily on illumination rather than aesthetics.

About the Author



Laura Schroeder is a traffic engineer in raSmith's Brookfield, Wis., office. She has been involved with several major Wisconsin Department of Transportation projects during her time at the firm. To ensure safety and efficiency in her projects, Laura uses traffic and work zone analysis tools such as Synchro and HCS.

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