A new kind of headlight that's already available in Europe and Canada but not yet legal in the U.S. could make driving safer at night by illuminating more of the road without blinding the drivers of oncoming cars, according to a new study from AAA.
Adaptive driving beam (ADB) headlights—also called smart headlights—shine as brightly as traditional lights with the high beams on, but they feature new technology that keeps any extra glare from shining into the eyes of drivers in oncoming cars.
Consumer Reports believes the National Highway Traffic Safety Administration should approve a proposed change to safety standards that would allow automakers to install them on vehicles in the U.S.
"Any technology, including ADB, that can allow drivers to take advantage of that increase in seeing distance that high beams provide without causing glare to oncoming or followed vehicles is a plus for night driving safety," says Jennifer Stockburger, director of operations at CR's auto test center and head of CR's headlight test program.
Traditional low-beam headlights often don't provide enough illumination for drivers to always see a vehicle, pedestrian, animal, or object in time to brake to avoid hitting it, Stockburger says. Turning on the high beams can solve the problem, but the majority of drivers (64 percent, according to a recent AAA survey) do not use the high beams regularly. Also, some drivers complain that auto-dimmer features—designed to switch off the high beams in the presence of an oncoming vehicle—are too slow to react and can cast dangerous glare into the eyes of drivers in oncoming cars.
Some ADB smart headlights get around this problem by using physical shutters within the headlamp assembly to shade oncoming cars, like an umbrella blocking the sun. Other ADBs are made up of multiple LEDs and can turn off a few of them when they detect a car approaching, so the light doesn't shine directly at drivers in oncoming vehicles.
Concerns About Glare
To see how ADB headlights perform vs. traditional ones, AAA compared pairs of identical vehicles—two Audi A8 and two Mercedes-Benz E-Class cars—equipped with the different headlight technologies.
AAA found that ADB lights consistently provided better illumination in the presence of an oncoming vehicle—as much as 86 percent better. And for oncoming drivers, ADB lights produced approximately the same amount of glare as traditional low-beam headlights while still providing the benefit of additional illumination.
Allowing the lights in the U.S. would require NHTSA to amend the Federal Motor Vehicle Safety Standards (FVMSS). Historically, glare has been a key concern for NHTSA, and it's one reason this change has been awaiting action for years, says William Wallace, senior policy analyst at CR.
In October, NHTSA proposed changing its standards to permit ADB headlights. Automakers, including Audi, Honda, Toyota, and Volkswagen, and safety advocates—including AAA and CR—have submitted comments and research in support of allowing ADB headlights on U.S. vehicles.
"We absolutely support the technology and will turn it on once approved," says Mark Dahncke, a spokesman for Audi. The company already has the hardware built into its U.S. cars; it would just need to update software to make it work correctly, he says.
Expensive Upgrade
If ADB lights do become available in the U.S., they won't be cheap: On the cars that AAA tested, the ADB-compatible headlights cost between $3,400 and $6,600 more than traditional headlights.
In the meantime, drivers should use their high-beam headlights while driving at night, taking care to turn them off as needed to avoid producing excess glare for oncoming drivers. "In our own headlight tests, high beams on average illuminate approximately 250 feet farther than the average low beams," Stockburger says.
CR estimates that it takes approximately 308 feet to see, react to, and stop for an obstacle while traveling at 60 mph. The 250 feet of additional illumination that ADB headlights provide could mean the difference between stopping in time and not stopping in time, Stockburger says. Indeed, fatality rates for drivers and pedestrians are higher at night than during the day.
"We're urging the government to allow ADB systems, but this should be just the start of a serious effort to improve nighttime road safety—not the end," Wallace says. "As new headlight systems roll out, NHTSA should require manufacturers to give the agency details about their performance and the consumer experience with them. NHTSA then could use that information to strengthen and fine-tune safety standards, especially to help protect pedestrians, cyclists, and other more vulnerable road users."
Headlight Testing
Properly functioning headlights are a vital part of car safety. On the "Consumer 101" TV show, Consumer Reports' expert Jen Stockberger explains how CR puts them to the test.