Good Headlights Reduce Crashes by 19%, Says IIHS Study
As daylight becomes a scarce commodity in the winter months, drivers are more likely to find themselves behind the wheel before dawn or after dusk. Nighttime driving is three times riskier than driving in broad daylight, according to the Insurance Institute for Highway Safety, in part because of compromised visibility (among other factors). As part of its safety-related efforts, the IIHS conducted a study on the impact of headlight quality on a variety of nighttime crashes. The results show significant improvements in crash rates for vehicles with good-rated headlights compared to those with a poor rating.
Related: Not a Shot in the Dark: 11 Cars Improve IIHS Headlight Safety Ratings
Crash tests and advanced driver assistance systems often steal the spotlight for vehicle safety criteria, but headlight quality shouldn’t be overlooked. The latest IIHS study shows why headlight quality plays an important role in determining if a vehicle lands on the organization’s most coveted Top Safety Pick Plus list.
Headlight Study Results
The study evaluated 44,000 single-vehicle crashes that happened at night. All 187 vehicles studied were equipped with IIHS-rated headlight systems. When controlling for factors unrelated to visibility, headlights with good ratings reduced crashes by 19% compared to those with poor ratings. Vehicles with headlights rated acceptable or marginal reduced crash rates by 15% and 10%, respectively.
The results are even more pronounced for crashes involving driver injuries and pedestrians. Good-rated headlights reduced accidents resulting in driver injury by 29%, and pedestrian crashes by 23%, compared to poor-rated headlights.
The Headlight Difference
Unlike federal headlight regulations that only dictate brightness levels, IIHS headlight ratings are based on multiple factors evaluated on a test track. The tests measure how well the vehicle’s low and high beams illuminate the track on curves and straightaways at speeds of 40-50 mph. Differences in low-beam illumination distance (from 125 feet to 460 feet according to IIHS’ testing) can mean a 4-second difference in seeing a potential hazard on the road. Visibility for other drivers is also a consideration, and points are deducted if excessive glare is identified.
Headlight quality is oftentimes the deciding factor in determining if a vehicle qualifies for one of IIHS’ top awards. To earn a Top Safety Pick, at least one set of a vehicle’s available headlight systems must earn a good or acceptable rating. A Top Safety Pick Plus award requires that all available headlights on every trim earn a good or acceptable rating.
For example, the 2021 Ford F-150 became an IIHS Top Safety Pick thanks to improved headlight options, although it missed out on being named a Top Safety Pick Plus because not all trim levels offered the improved headlights. Other examples of vehicles that earned a Top Safety Pick Plus award for 2021 after eliminating lower-rated headlight options include the Honda Accord, Hyundai Palisade, Subaru Ascent and Toyota Highlander.
It’s Easier to Find Good Headlights
The stringent criteria set by the IIHS motivated automakers to improve headlight quality in their vehicles in pursuit of the Top Safety Pick awards. Since implementing the headlight rating system in 2016, the proportion of good-rated headlights increased from 4% to 29%, and the average low-beam illumination distance grew from 180 to 200 feet. Headlight glare has also been reduced from 15% above IIHS’ acceptable threshold in 2016 to 10% below the threshold in 2020.
Tips for Nighttime Driving
In addition to considering a vehicle’s headlight quality based on IIHS ratings, drivers can take proactive steps to make nighttime driving safer. The National Safety Council recommends properly adjusting the headlights, dimming the dashboard, looking away from oncoming lights, wearing anti-reflective glasses, keeping the windshield clean and slowing down.
More From Cars.com:
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- 2022 Hyundai Tucson Clinches Top IIHS Safety Rating
- Which Cars Have Self-Driving Features for 2021?
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