Fran Laub, a 77-year-old Vancouver resident, drives a 2003 Mercury Grand Marquis. She usually avoids nighttime driving, in part because of glare from the headlights of other vehicles.
“When I drive at night, those headlights hit me right in the eye because my car sits low,” she said. “It drives me insane, and it’s not just because I had glaucoma surgery.”
Headlights allow drivers to see where they are going at night and allow other drivers, bicyclists and pedestrians to see them. With increasing popularity of light emitting diode, or LED, headlights, some wonder if today’s headlights are too bright.
Josh Whitehead of Vancouver brought up headlights as part of The Columbian’s Clark Asks series, where readers suggest news stories and vote on which should be covered.
“Is having bright headlights legal?” he asked. “It shouldn’t be. I feel like I’m a deer who’s in a ‘Final Destination’ movie plot.”
Many readers share his concern. Whitehead’s question received 71 percent of votes, the second-highest margin of victory in the feature’s three-year history.
There’s no shortage of Americans who are worked up about headlights. About 13,700 people have signed an online petition to “Ban blinding headlights and save lives!”
Mark Baker of softlights.org sent The Columbian an email alleging “there is clearly a conspiracy happening by the auto industry and those who supposedly regulate industry regarding these eye-damaging LED headlights.”
Experts who have spent years studying headlights and traffic safety offer a different perspective.
“Lights are not brighter,” said Michael Flannagan, a research associate professor at the University of Michigan Transportation Research Institute in Ann Arbor, Mich. “By and large, the same laws have been in place for decades.”
“The standard for the intensity of the headlight hasn’t changed,” said David Aylor, manager of active safety testing for the Insurance Institute for Highway Safety in Ruckersville, Va. “That has been around since the ’70s.”
Complaints about overly bright headlights likely are triggered by improperly aimed headlights, vehicles that ride lower to the pavement, SUVs and pickup trucks with headlights mounted higher, an inherent human sensitivity to blue-white light emitted by high-intensity discharge and LED bulbs, and an aging population of motorists more susceptible to bright lights than younger drivers.
Some of these factors contribute to headlight glare, which has more to do with headlight aim and height than brightness.
Lowering maximum headlight heights has been discussed for 20 years, but state and federal law remains the same. Many drivers are unaware of the need for their headlights to be properly aimed. And even new vehicles are driven off dealer lots with poorly aimed headlights.
Headlight technology has come a long way from the acetylene or oil lights of the late 19th century, through sealed-beam headlights with one large assembly to the introduction of halogen bulbs in the mid-1980s.
Sgt. Darren Wright, a spokesman for the Washington State Patrol in Olympia, has spent nearly 29 years with the agency and remembers when incandescent headlights were replaced with halogen bulbs.
“Everyone complained about the halogen lights,” he said. “Now, no one would give up their halogen light for an incandescent light.”
LEDs continue to increase in popularity. They last longer, use less energy and are more versatile, which allows auto designers to create more stylish models.
Consumer Reports magazine, in an August 2019 article, reported that 86 percent of the 2019 model year vehicles it tested had LED headlights, compared with 55 percent of 2018 models.
There is disagreement over whether LEDs do a better job for drivers. Consumer Reports said its testing indicated that LEDs don’t provide any more roadway illumination than high intensity discharge or halogen bulbs. AAA, however, reports LEDs offer improved visibility, especially with low beams.
State law dictates when headlights must be used — 30 minutes after sunset to 30 minutes before sunrise or during conditions when people and vehicles are not “clearly discernible” from 1,000 feet — and stipulates that autos must have two headlights.
“We can’t search somebody’s car for what parts have been installed,” he said. “The Constitution protects people from unreasonable searches and seizures.”
Sgt. Brent Waddell of the Clark County Sheriff’s Office said his agency will issue citations for defective headlights, but it has no way to check headlight brightness. Kim Kapp, spokeswoman for the Vancouver Police Department, said the city’s officers will stop drivers for failing to dim their high beams, but Vancouver doesn’t have statistics for traffic stops regarding headlights.
Glare vs. brightness
No one disputes that headlights can cause glare, which has more to do with headlight aim than brightness. The Insurance Institute for Highway Safety says properly aimed low beams will illuminate the roadway without blinding drivers of oncoming vehicles. Conversely, badly aimed headlights can provide poor visibility to the driver but still cause excessive glare for other drivers.
“It’s just a matter of not how bright the light is but where’s it’s aimed,” Aylor said. “Often that headlight is glaring because it’s producing intense light right at our eyes.”
The Lighting Research Center, part of the Rensselaer Polytechnic Institute in Troy, N.Y., has identified headlight aiming at the biggest contributor to excessive glare. The center evaluated headlight aiming on more than 100 vehicles and found that two-thirds of the vehicles had at least one headlight not properly aimed. Nearly one-third of new cars had one or both headlights incorrectly aimed.
AAA divides glare into two categories. The automobile association says modern headlights rarely contribute to disability glare, which is a measurable reduction in a driver’s ability to see and often is worse in older drivers. Headlights can trigger discomfort glare, which creates an uncomfortable sensation, due to the light’s color and size.
Flannagan, of the University of Michigan Transportation Research Institute, said LED headlights with a bluish tint generate more complaints than older halogen lights with a yellow-white appearance.
“It seems to be entirely a subjective effect, without a corresponding effect on actual ability to see,” he said. “Researchers in this area have long distinguished between subjective glare, how much discomfort people report, and objective glare, how much glare actually reduces ability to see. Color seems to affect one but not the other.”
Newer headlights also create a sharper cutoff, a line between light and dark that can be seen when headlights are directed toward a wall or garage door, Flannagan said. The cutoff protects oncoming drivers from being hit with too much light, but it can cause a problem for drivers meeting near the crest of a hill.
“If there is a mis-aim or if the car bounces a bit or if you meet on a hill, you could get this sharp flash,” he said.
The Lighting Research Center concluded that restricting headlight height to 1 meter, or 39.4 inches, would reduce glare for oncoming drivers. Higher mounting heights significantly increase glare for other drivers. The recommended 1 meter maximum is the midpoint of permissible range for headlight height, 24 to 54 inches, under Washington state law, RCW 46.37.040.
Flannagan said a 54-inch maximum also is the federal standard. SAE International, previously the Society of Automotive Engineers, concluded that headlights should be mounted no more than 33.5 inches above the road, he said.
“Does that mean state and federal standards allow headlights that are too high?
“That’s what SAE says,” Flannagan replied. “Headlamps should not be as high as 54 inches.”
Glare has been recognized as a problem for more than 100 years by headlight designers, Flannagan said, but any connection between glare and crashes is sketchy at best.
“There is very little if any evidence to indicate that glare causes any crashes at night, and it is probably very strongly a perception,” he said.
Seniors are more susceptible to glare. As drivers’ eyes age, the pupils let in less light, and they need more time to recover from glare. Cataracts and other medical issues can contribute to difficulty driving at night.
“The old advice is still the best,” Flannagan said. “Don’t look directly at oncoming lamps. Look slightly to the right.”