Modern technology has improved many aspects of the driving experience. Most ease operator workload by automating various tasks like turning lights on and off at appropriate times, engaging windshield wipers and controlling their speeds and intervals, verbally giving directions and allowing optimum situational awareness through multiple cameras.
And while distraction typically affects the occupants of the vehicle, headlights have the ability to cause dangerous conditions for your fellow road warriors.
Headlights weren't always bright or even effective at helping the driver see at night. The earliest headlights were oil-burning lamps intended to help others see a vehicle as much as to illuminate the roadway, although the latter was optimistic considering the limitations of the kerosene-fueled lanterns in use.
In 1904, “Prest-O-Lite” acetylene-fueled lamps followed with their stronger resistance to wind and weather, but like most innovations, necessity became the mother of invention. Peerless offered electric headlamps as standard equipment in 1908, and in 1912, Cadillac created the first automotive electrical system by integrating their Delco ignition and lighting system. The first modern headlight bulb consisting of low beam and high beam was introduced in 1924 and three years later, the foot-operated dimmer switch was invented (remember those?).
Headlight technology remained stagnant until the 1940s, when sealed beam headlights became commonplace. These singular units combined the lens, reflector and filament. The next leap placed the incandescent filament within a pressurized gas, allowing higher lumen output, and the halogen bulb was born.
The first halogen headlamp debuted in Europe in 1962 but wasn't used in the U.S. Until 1978, when increased headlight intensity was allowed, and halogen headlamps were the most efficient means of achieving it.
By 1991, HID (High Intensity Discharge) headlamps appeared on higher-end BMWs and became an option on many vehicles over time. These lamps electrically charge xenon gas, which illuminates much the way a basic fluorescent tube-type bulb functions.
Finally, the latest evolution of the headlight consists of LED (or Light Emitting Diode) technology. LEDs are bright, efficient and small, allowing designers to blend effective lighting into ever more streamlined forms.
While HID and LED lighting can pierce the darkness, however, they can also dazzle and blind oncoming traffic with their glare.
The National Highway Traffic Safety Administration sought public comments regarding this issue and received complaints in the thousands. There are standards in place regarding headlight design and function, and they’re spelled out in Federal Motor Vehicle Safety Standards 108, and even though these standards have remained relatively unchanged, vehicle design and implementation hasn’t.
FMVSS is a document that’s about as long as a Route 95, complete with dry text, legalese, charts, graphs and diagrams. Compound the federal standard with individual state rules targeting headlights, and there seems to be plenty of confusion to go around.
Most newer headlight designs provide a shade that effectively cuts off the high beam at the horizontal line. Picture a cone of light originating at the headlight and expanding as it shines ahead. The shade would cut that beam down the middle horizontally to limit the light exposure above. This complies with a key element of the rules that dictates how much light a headlight can shine above the horizontal plane of the low beam.
The difference between a modern high beam and low beam is the overall area that’s illuminated as much as the actual brightness.
So if a pickup truck is approaching with its headlights mounted high in that enormous new grille that resembles the side of a chrome battleship, that horizontal beam cut-off line is probably at eye level or higher when compared to an oncoming car or small crossover SUV, which means the driver of that oncoming car is getting the full brightness of that trucks headlight.
Similarly, a truck or SUV following closely behind a smaller vehicle filters the full intensity of its headlight through the cabin of the vehicle ahead. And since trucks and large SUVs are the hottest-selling vehicle market in the U.S. right now, there are plenty of them out there.
LEDs also make it easy to engineer the actual color output of the light. Early incandescent and halogen bulbs were distinctly yellow in color, while new LEDs are a cleaner white or slightly blue. The color spectrum doesn’t change the intensity of the light, but it does contribute to glare and dazzle, perhaps in the way the eye interprets these different colors.
The next level of safety with LED headlights will come in the form of adaptive technology. This will control lighting parameters by sensing oncoming traffic and shaping specific aspects of the lights to prevent blinding other drivers while still providing the best illumination for the operator of the vehicle. Hopefully it works as it approaches vehicles from the rear, too.
Still further down the road, as automation technology improves, there may come a time when lighting becomes less important. As self-driving cars take over the task of “seeing,” lamps may again resume the role of helping others see a vehicle coming rather than illuminate where it’s going.
Eric and Michelle Meltzer own and operate Fryeburg Motors, a licensed, full-service automotive sales and service facility at 299 Main St. in Fryeburg, Maine. More than a business, cars are a passion, and they appreciate anything that drives, rides, floats or flies.