Headlights & Safety
The Most Underrated
Safety Feature on Your Car
Half of all traffic deaths happen in the dark. Good headlights cut nighttime crashes by 19% and pedestrian crashes by 23%. Yet most buyers never check their headlight rating.
All data from IIHS headlight evaluations β the only program that tests how well your headlights actually illuminate the road.
π Half of All Traffic Deaths Happen in the Dark
Nighttime driving is inherently more dangerous β reduced visibility, fatigue, and impaired drivers all converge. Your headlights are your only defense against what you can't see.
happen in the dark
deaths since 2010
at night
π΄ The math is sobering: Only about a quarter of driving happens at night, but roughly half of all traffic deaths occur during dark hours. That's a 3Γ higher death rate per mile compared to daytime driving. Better headlights can't fix fatigue or impaired driving β but they can fix the visibility problem that contributes to thousands of deaths every year.
π What Good Headlights Actually Do
IIHS has been rating headlights since 2016. Their research proves better headlights save lives.
Vehicles with IIHS "Good" headlights have 19% fewer nighttime single-vehicle crashes than those with "Poor" headlights.
Good headlights reduce nighttime pedestrian crashes by 23% β seeing a person in the road 1-2 seconds sooner can mean the difference between braking and a fatality.
Crashes that do happen with Good headlights are less severe β 29% fewer result in driver injuries, likely because earlier visibility allows partial braking.
Good-rated headlights reduced tow-away crashes by about a quarter, meaning less severe total damage in the crashes that still occur.
| IIHS Rating | Nighttime Crash Reduction | % of Cars (2016) | % of Cars (2025) |
|---|---|---|---|
| Good | -19% | 4% | 51% |
| Acceptable | -15% | β | β |
| Marginal | -10% | β | β |
| Poor | Baseline | ~60% | Declining |
π‘ The IIHS effect: When IIHS started rating headlights in 2016, only 4% earned "Good." By 2025, 51% earn "Good." Average illumination distance grew from under 180 feet to over 200 feet. Excessive low-beam glare dropped from 21% of systems to just 3%. Rating headlights and making it a requirement for safety awards forced the entire industry to improve.
π¬ How IIHS Tests Headlights
This is the only comprehensive headlight evaluation in the U.S. NHTSA does not test headlights at all.
The IIHS headlight test protocol
IIHS drives each vehicle on a closed track with five distinct approaches while light sensors on the road measure exactly how far the headlights illuminate to a useful level (at least 5 lux at 10 inches above ground):
Additionally, IIHS measures glare from low beams that could blind oncoming drivers. Headlights are tested exactly as they come from the dealer β no adjustments, reflecting real-world conditions.
What separates Good from Poor
- Illuminate 300+ feet on straightaways
- Excellent curve illumination
- Minimal glare to oncoming drivers
- Often LED or adaptive systems
- May illuminate only 130-160 feet
- Nearly blind on curves
- Can produce excessive glare
- Often base-model halogen bulbs
β‘ At 60 mph you cover 88 feet per second. If your headlights illuminate only 150 feet, you have less than 1.7 seconds to see an obstacle, recognize it, and react. With Good headlights illuminating 300+ feet, that jumps to over 3.4 seconds β enough time to brake and avoid a crash entirely. This is why headlight quality directly correlates with crash reduction.
π Headlights & Other Drivers: The Glare Problem
Your headlights don't just affect you β they affect every driver coming the other way.
The perception problem
Over 90% of drivers report being regularly distracted by oncoming headlights. More than half say they've reduced or avoided night driving because of glare. Older drivers are especially affected β age-related changes to the eye's lens cause more light scattering, making glare recovery take longer.
What the data actually shows
Surprisingly, IIHS analysis of nearly 24 million crash reports found that headlight glare was cited in only 0.1% to 0.2% of nighttime crashes across 11 U.S. states β and this percentage has remained stable even as headlights have gotten brighter. The real danger isn't too much light β it's too little.
attributed to glare
attributed to darkness
Why glare feels worse than it is
SUV and truck headlights sit higher, shining directly into sedan mirrors and windshields. The proliferation of taller vehicles has made this worse.
Factory or post-repair misalignment directs light into oncoming drivers' eyes rather than onto the road. This is a major contributor to perceived glare.
LED headlights emit whiter, bluer light that scatters more in the human eye β especially through dirty windshields β creating more discomfort even at the same lux level.
Non-compliant LEDs installed in halogen housings produce scattered, unfocused beams that are genuinely dangerous. These are unregulated and increasingly common.
π The key insight: Good headlights help the driver and other road users. IIHS tests for excessive glare as part of their rating β headlights that blind oncoming drivers get downgraded. The best modern headlight systems provide Superior illumination for the driver while producing less glare than older designs. Excessive glare from low beams dropped from 21% of systems in 2017 to just 3% by 2025.
π¦ The Future: Adaptive Driving Beams
The technology that solves both visibility and glare already exists β but the U.S. has been slow to allow it.
How Adaptive Driving Beams (ADB) work
ADB systems use cameras to detect oncoming vehicles and automatically carve out "shadow zones" in the beam pattern β keeping high-beam-level illumination everywhere except where oncoming drivers' eyes are. The result: you get near-high-beam visibility without blinding anyone.
- High-beam illumination on empty roads
- Automatic dimming for oncoming traffic
- Dramatically better curve visibility
- No driver action needed
- Available in Europe for years
- U.S. legalized in 2022 (Infrastructure Law)
- Slowly reaching U.S. market
- Available on some BMW, Mercedes, Audi models
Curve-adaptive headlights
Even without full ADB, curve-adaptive headlights β which swivel the beam direction based on steering input β provide meaningful safety benefits. HLDI (the insurance arm of IIHS) found that vehicles with curve-adaptive headlights have lower nighttime collision and property damage claim rates compared to standard headlights. On winding roads at night, being able to see around the curve before you enter it is the difference between safe driving and driving blind.
π What This Means for Car Buyers
Headlights are one of the easiest safety features to check β and one of the most impactful to get right.
1. β Check the IIHS headlight rating
IIHS rates headlights as Good, Acceptable, Marginal, or Poor. An "Acceptable" or "Good" rating is required for any IIHS Top Safety Pick or Top Safety Pick+ award. If a car doesn't have at least "Acceptable" headlights, it cannot earn the top safety designation β that's how important IIHS considers them.
2. π‘ Check which trim level has the good headlights
This is critical: headlight ratings often vary by trim. The base model may have "Poor" halogen headlights while the higher trim gets "Good" LEDs. IIHS rates each headlight system separately. Don't assume the base model has the same headlights as the reviewed trim.
3. β οΈ Avoid aftermarket LED bulbs
Dropping LED bulbs into housings designed for halogen bulbs creates scattered, unfocused beams that blind other drivers and may actually reduce your own visibility. If you want better headlights, upgrade the entire headlight assembly β or, better yet, buy a vehicle that comes with good headlights from the factory.
4. π§ Get your headlights aimed
Even good headlights perform poorly if they're aimed wrong. After a front-end repair, bumper replacement, or if you carry heavy loads in the trunk, have a mechanic check your headlight aim. Mis-aimed headlights are one of the top causes of glare complaints β and reduced visibility for you.
π΄ NHTSA doesn't test headlights at all. The 5-star rating on the window sticker tells you nothing about headlight quality. A car can earn 5 stars from NHTSA with headlights that barely illuminate 150 feet β far too little at highway speeds. Learn more about NHTSA's limitations β
πΆ Headlights & Pedestrian Safety
The 23% reduction in pedestrian crashes from good headlights is one of the most important safety findings in recent years.
Pedestrian fatalities have surged 77% since 2010, driven by three converging trends:
Smartphones in cars
Higher, blunter front ends
Inadequate street lighting
Good headlights directly address the third factor. Seeing a pedestrian at 300 feet vs 150 feet at highway speed gives a driver an extra 1.7 seconds to react β often enough to brake completely or steer around. For city driving at 35 mph, those extra feet translate to even more reaction time. This is why IIHS data shows a 23% reduction in nighttime pedestrian crashes with Good-rated headlights.
π Headlights + AEB = compounding safety: Automatic Emergency Braking (AEB) relies on cameras and radar to detect pedestrians β but human reaction time still matters. Good headlights let the driver see and react sooner, while AEB acts as a backup. Vehicles with both Good headlights and effective pedestrian AEB provide the strongest protection for people outside the car. See which vehicles endanger others most β
Explore More Safety Data
Sources: IIHS headlight evaluation program (2016β2025), IIHS Status Report (Vol. 57, No. 3), HLDI Bulletin β curve-adaptive headlights and insurance claims, IIHS analysis of 24 million nighttime crash reports (2015β2023), NHTSA Fatality Analysis Reporting System (FARS).