American drivers have a blinding headlight problem. It could last for years
Drivers say they’re routinely getting blinded by surrounding cars’ headlights.
This isn’t because headlight regulations have changed — regulations on brightness haven’t been altered in decades.
In reality, it’s due to misaligned headlights, taller vehicles, and the changing hue of the lights.
Since moving away from the suburbs and into Chicago, Ashley Seery’s been blinded by headlights more than ever. She said she doesn’t even drive at night anymore in an attempt to remedy the problem.
“It’s to the point where I will avoid driving at night because some headlights are just so bright,” Seery said. “They can literally blind me. I have to turn my mirrors away so that I can drive in peace without the glare.”
Seery’s not alone. There are entire communities and online petitions devoted to discussing blinding headlights.
This isn’t because headlight regulations have shifted — they haven’t changed in decades, according to Greg Brannon, AAA’s director of automotive engineering. But the lights themselves have.
John Bullough, the program director at the Light and Health Research Center at the Icahn School of Medicine at Mount Sinai has been sounding the alarm on the topic for years. Bullough, who works closely with headlights and vehicle manufacturers to try to address the issues, said there are three primary factors that have shifted in the past few decades that caused headlights to appear brighter and cause more glare.
First off, vehicles, especially in the U.S., are getting taller and taller. Adding to that, the color of many headlights has shifted from a warmer, yellow hue to a harsher, blue-white one. And finally, most cars have at least one headlight that’s misaligned. This isn’t a new problem, but other shifts have made it into a serious issue.
The misalignment problem
The most important factor, Bullough said, is how common it is for cars to have headlights out of alignment.
“We actually did some measurements not too long ago and found that probably about two-thirds of every car had at least one headlight that was either aimed too high up, which is something that creates a lot of glare for other drivers, or too far down, which essentially limits their visibility.”
A key issue is that, as cars are produced, there isn’t a specific entity tasked with ensuring alignment.
Matt Brumbelow, a senior research engineer at the Insurance Institute for Highway Safety, explained that the federal regulations over car headlights are “equipment-based standards only,” meaning that the headlight is certified independently of the vehicle itself.
After installation, “there’s no testing to make sure that it’s still aimed properly or that it’s putting out enough light on the road and it’s not glaring other drivers,” Brumbelow said.
Americans love a big truck
Another contributing factor, Bullough explained, is the size (and height) of the average car is increasing. And as cars get taller, he said, the placement of the headlights rises alongside it. This, in turn, can lead to an increase in drivers getting blinded.
According to JD Power, a consumer intelligence company, 52.7% of vehicles sold in 2010 were either SUVs or trucks. By 2021, that number was to up to 78.5%.
American cars are bigger than vehicles from many other countries for several reasons, according to MotorBiscuit, including larger streets, lower gas prices, and the desire for more room.
Higher vehicles mean the band of light is raised up by foot or more, Bullough said. “That means that there’s going to be more opportunity to create glare for other drivers as well.”
The 405 Freeway in California during rush hour traffic.
Patrick T. Fallon/AFP via Getty Images
The changing hue of car headlights
As cars have modernized, many manufacturers have moved away from the standard halogen bulb — which produces a yellowish light — in lieu of LEDs, which usually produce a bluer, white light.
According to Mark Rea, a professor at the Mount Sinai Icahn School of Medicine, there is a fundamental issue with how light is measured: There’s bias against certain blue hues in the spectrum.
A warm, yellowish hue of light is gentler to the human eye.
This is where, to many, the problem lies: the shine of an LED light — due to its added blue light — appears to be brighter than a warmer yellow halogen headlight despite generating the same amount of candlepower, a unit used to measure light.
“The eye is sensitive to those blue wavelengths, but the light meter is not,” Rea added.
There’s a solution, but it’s years away
In February 2022, after being required to by Congress’ Bipartisan Infrastructure Law, the National Highway Traffic Safety Administration issued a rule officially allowing automakers to install adaptive driving beam headlights onto new vehicles.
Adaptive driving beams automatically adjust the high beams emitted from LED car headlights in real time to avoid blinding pedestrians and other drivers.
The tech has been legal in most countries outside of the US, and experts say they could make a noticeable difference once rolled out.
But don’t expect to see it anytime soon on American roads due to the complexity of the NHTSA’s regulations around adaptive driving beams, which differ tremendously from Europe.
“We’re still not aware of any that are available in the US, so it might take a few years for the manufacturers to make sure that their high beam or their adaptive driving beam technology meets the requirements that the NHTSA has released,” Brumbelow said.
But there isn’t any legislation or regulations in place that’ll force manufacturers to implement adaptive driving beams into their vehicle lines by a certain date.
So prepare for the immediate future to be even brighter, as the blinding glare problem may get worse before it gets better.