NOVEMBER 29, 2018
Just over half of 2018 model vehicles IIHS evaluated are available with headlights that do an adequate job of lighting the road at night and limiting glare for oncoming drivers.
However, most good rated headlights are optional or bundled with features that can raise the price of the vehicle." Consumers shouldn’t have to buy a fully loaded vehicle to get the headlights they need to safely drive at night," says David Aylor, manager of active safety testing at IIHS. "All new vehicles should come with good headlights."
Since the Institute released its first headlight ratings for passenger vehicles in 2016, most manufacturers have focused on improving this key safety component (see "In the dark: New ratings show most headlights need improvement," March 30, 2016). That year, only 2 of 95 headlight systems on 2016 model vehicles IIHS evaluated earned a good rating.
For the 2018 model year:
Good rated headlights are needed to qualify for a 2018 TOP SAFETY PICK+ award, and good - or acceptable rated headlights are a requirement for TOP SAFETY PICK. The Institute is evaluating headlights on contenders for the 2019 awards which will be announced in December 2019.
A single model may have several different headlight options, and the Institute tries to test all of them as the vehicles arrive on dealer lots. In all, IIHS engineers evaluated 424 headlight variants on 2018 models. Of these, 67 percent earn a marginal or poor rating because of inadequate visibility, excessive glare from low beams for oncoming drivers, or both.
The Genesis G90, a large luxury sedan, and the Lexus NX, a midsize luxury SUV, are the only 2018 models evaluated that come with good rated headlights, no matter the trim line or options package.
The best available headlights on the Chevrolet Volt, Genesis G80, Mercedes Benz E-Class and Toyota Camry are rated good, while the lowest are rated acceptable.
Fifteen other models have acceptable rated headlights across the board.
For most other vehicles, though, the difference in headlight performance among trim lines is night and day.
A case in point is the Hyundai Kona. The good rated LED projector headlights on the high end Kona illuminated almost 450 feet on the right side of the road in the straightaway test for low beams.
However, the small SUV’s poor rated base model halogen projector low beams only illuminated 220 feet on the right side of the straightaway, far short of the optimal 325 feet to provide at least 5 lux illumination.
"The Kona’s LED low beams should give a driver traveling straight at 65 mph enough time to identify an obstacle in the road and brake to a stop," Aylor says. "In contrast, someone with the halogen lights would need to drive 25 mph slower to have enough time to react to avoid a crash."
The Kona is among the 17 vehicles with good rated headlights that also have poor rated variants. The Hyundai Sonata and its twin, the Kia Optima, are in this group, too.
Consumers have to pick a top trim line to get the best available headlights–on 2018 models,
"In the past two years, manufacturers have made changes to improve headlights, whether through better aim or the light source itself," Aylor says. "But we still see a lot of models where the base headlight is poor, so buyers really have to do their homework to make sure they are getting the best available headlights."
He adds, "Unless you go for a test drive at night, IIHS ratings are the only way to know whether the vehicle you’re considering will have good headlights."
Toyota and its Lexus luxury brand lead the way with the most 2018 models that only offer headlights that rate good or acceptable. Still, three Toyota models–the 4Runner, C-HR and Yaris iA–are only available with poor headlights.
The Kona’s LED projector low beams cast enough light for a driver to spot the pedestrian and deer straight ahead. In comparison, the halogen projector low beams don’t light up enough of the road for the driver to see the targets at the same distance.
The 4Runner’s halogen projector headlights, for instance, rate poor because the midsize SUV’s low beams don’t provide enough light on gradual and sharp curves, and they also create some glare. Light from the high beams is inadequate on sharp curves.
Most headlights use one of three light sources: halogen, high intensity discharge (HID) or LED. Each of these can be paired with either a multifaceted reflector or a projector lens. Projector headlights use one lens to spread the light out, while reflectors use shiny surfaces that bounce the light forward.
Domestic manufacturers, in general, have room for improvement, especially when it comes to pickup trucks. Poor rated headlights are the only ones available on Ford’s popular F-150 and Chevrolet’s Silverado 1500, for example. That is also the case for the Chevrolet Colorado, GMC Canyon and Nissan Frontier.
"Pickups are proportionally more likely than cars to be involved in fatal single vehicle run off the road crashes. Better headlights might help reduce crashes like these at night," Aylor says.
The Honda Ridgeline is the only pickup with available headlights that earn a good rating. Consumers will have to go for one of the top two trim lines to get them, though, paying nearly $12,000 more than the base model which only comes with poor rated headlights.
Bundling advanced safety features with things like leather seats and entertainment packages is a common industry practice that can add thousands of dollars to the price of a new vehicle.
The best available headlights on the Kia Soul, for instance, earn a good rating, but consumers must buy a $3,000 or $6,000 options package on one of the top two trim lines to get them. This pushes the small car’s price to nearly $26,000, compared with about $16,000 for the base model and its poor rated headlights.
The 2018 Kia Sedona’s HID projector headlights are rated good. To get them, consumers need to buy the SX trim line equipped with the Advanced Touring package or the SXL trim line. The minivan’s other trim lines have halogen projector headlights rated poor. These lamps produce excessive glare.
Headlights are essential crash avoidance technology. About half of all fatal crashes in the U.S. occur in the dark, and more than a quarter occur on unlit roads.
Headlights have an obvious role to play in preventing nighttime crashes, but not all headlights perform their job equally. Differences in light source, headlight technology and even something as simple as how the lights are aimed all affect the amount of useful light supplied.
Properly aimed low beams light up the road ahead without temporarily blinding drivers of oncoming vehicles.
Subaru is among a handful of manufacturers that made running changes to certain 2018 models to improve ratings, mostly by readjusting headlight aim. As a result, the Crosstrek moved to a good rating from poor for its best available headlights, the Forester climbed to acceptable from marginal, and the Outback rose to good from acceptable.
Other manufacturers that made similar running changes are Hyundai/Kia, Mazda, Mercedes-Benz, Volkswagen and Volvo.
In IIHS evaluations, engineers measure the reach of a vehicle’s headlights as the vehicle travels straight and on curves. Each rating provides information on the amount of visibility provided by low beams and high beams and whether the glare produced for other drivers is excessive.
Low beams are weighted more heavily than high beams because they are used more often. IIHS weights the readings on the straightaway more heavily than those on the curves because crashes are more common on straight sections of road.
"Properly aimed headlights that are bright enough to illuminate the road but not enough to bother oncoming drivers can make nighttime driving less stressful and help drivers avoid crashes," Aylor says. "Good headlights also improve the chances that attentive drivers will see pedestrians in time to slow down for them."
High beam assist is quickly gaining traction–45 percent of the 2018 models evaluated have the feature, up from 37 percent in 2017. High beam assist automatically switches between high beams and low beams depending on the presence of other vehicles.
Research shows drivers rarely turn on their high beams. High beam assist helps boost driver use of high beams. Vehicles with the feature get extra credit in IIHS headlight evaluations.
