IIHS: Headlight Glare Implicated in Small Percentage of Crashes

The unpleasant experience of bright headlights making nighttime drivers wince may not be as dangerous as most would believe—and headlights could be becoming even safer.

Glare is implicated in a small fraction of nighttime crashes, a new study from the Insurance Institute for Highway Safety shows.

The IIHS study of roughly 6 million nighttime crashes found that headlight glare was cited as a factor in only one or two out of every 1,000 nighttime crashes from 2015 to 2023.

The study, which looked across 11 U.S. states, also found there was little change in how often glare was mentioned in crash reports during the period. Headlights have been improving considerably in how well they light the road since IIHS launched its headlight ratings test back in 2016.

The ratings program led manufacturers to use LED headlamps on more models. The IIHS ratings penalize headlights whose low beams produce excessive glare that can temporarily blind oncoming drivers. By factoring in both visibility and glare, IIHS ratings led automakers to pay attention to headlight aim.

When the Institute released its first headlight ratings in 2016, one out of more than 80 headlight systems evaluated received a good rating, compared with more than half (51%) of the headlights IIHS tested on model year 2025 vehicles.

In addition to improving the visibility provided by headlights, automakers have reduced the amount of glare headlights produce. In testing, 21% of the headlights available on 2017 models produced excessive glare. For 2025 models, 3% produced excessive glare, according to the IIHS.