If you’ve operated an automobile over the last decade or so, you’ve probably been aware that headlights have become exceedingly obnoxious. Ford Super Duty drivers, in particular, must spend half their nighttime driving flashing oncoming drivers that, no, their high beams aren’t on, but their low beams are so blinding that it makes the high beams irrelevant.
The answer why everyone’s headlights are so blindingly obnoxious is: Because you live in the United States.
The United States — the most technologically advanced nation on the face of planet Earth — has been historically backwards in lighting technology for the last 50 years, and that’s only starting to change in 2018.
To give you an idea of the inertia surrounding headlamp technology, cars in the United States went from 1939 all the way to about 1986 — 45 years — with exactly the same headlamp design, with the exception of the shape and the bulb type. They were called Sealed Beams and they were the bane of the automotive designer’s existence.
A sealed beam headlamp is a light comprised of a parabolic reflector, a filament (or filaments) and a glass lens all permanently sealed together as a unit. When two seven-inch sealed beam headlamps — with both high- and low-beam filaments — were required by federal law in 1939, they were definitely an advancement, not just in terms of lighting, but reliability.
In the earliest days of automotive history, acetylene lights were the standard, long before electrical systems were powerful enough to operate headlamps. Electric headlamps wouldn’t become required standard equipment until 1911, and then the sealed beam, which made headlamps much more reliable and long-lasting was fairly quickly adopted as the standard in 1939.
That standard remained barely unchanged for the next half century. There were a few isolated changes. Between 1939 and 1956, every car in the U.S. had to have two, round, seven-inch sealed beams with high and low beams. In 1957, manufacturers were allowed to separate the high and low beams into individual lamps, allowing designers to use four 5 3/4″ round headlamps rather than two.
For the next 15 years, the only advancement in lighting technology allowed in the United States regarded the shape of the sealed beam. In 1974, NHTSA allowed the introduction of four rectangular headlamps, 4-inches by 6 1/2-inches in size. A year later, two-bulb rectangular headlamps were authorized.
Yet the technology inside those lamps didn’t change at all. By the mid-1960s, Europe had recognized the superior lighting advantage of halogen gas and had incorporated it into headlamp designs immediately upon is successful testing in automotive applications.
“Single filament H1, H2, and H3 light sources were made and used in headlamps and other lighting applications on vehicles in Europe. The double-filament H4 bulb was used in the late sixties in European headlamps,” reads an excellent history of automotive lighting written by David W. Moore for the University of Michigan in 1998.
Federal Motor Vehicle Safety Standards came into place in 1968, and it was like they were fixed in amber while the entire world enjoyed all kinds of safety and technology advancements. The requirement that headlamp beams be fixed, for example, meant that cars in the United States couldn’t have beams that turned with the steering wheels as the Citroen DS had in the 1960s:
As halogen lighting became more prevalent, other advantages became obvious for automotive engineers and designers. For example, a halogen bulb didn’t require the hermetic seal that a tungsten filament did in a sealed beam. As a result, just the bulb could be replaced, leaving the reflector and lens permanently fixed to the car. That allowed designers and engineers to construct headlamp and reflector assemblies of both glass and composites, allowing for much better aerodynamics and more unique aesthetics that the round or square sealed beams.
Looks cool, right? NOT SO FAST, WEALTHY AMERICAN CAR SHOPPER.
While the Mercedes-Benz owner in Europe could enjoy superior lighting technology and better aerodynamics and aesthetics, we schlubs in America got retrofitted round beams jammed in a square hole.
Along with all the performance cars the rest of the world got, we were saddled with technology dating from 1939.
Halogen did finally make its way to the United States officially in 1983, approximately 20 years after it had been introduced in Europe, and composite headlamps started to appear in the 1984 model year.
We were similarly years behind with high-intensity discharge headlamps. HIDs had been in use commercially for years, but early versions had long startup times, which was fine in a commercial building, but not good in a car, which requires headlamps to turn on instantly, sometimes multiple times in a single trip.
Those issues were solved by the mid-1980s, and automotive engineers around the world went to work designing headlamps that could take advantage of the technology. European engineers used the H4 Halogen light source and then brighter Xenon-gas bulbs, and newly developed optical computer-lighting programs allowed smooth, computer-generated surfaces to form the beam pattern without having any optics in the lens.
These HID lamps are fantastic at throwing light, but they often throw it where it’s not wanted, specifically in the eyes of oncoming drivers. Again, Europe figured this stuff out years ago, while we’re literally blindly bumbling along with the same regulations we had when George W. Bush was still in office.
Companies like Mercedes-Benz and Audi have introduced multibeam smart headlamps that simultaneously increase brightness on the road ahead, while reducing glare for oncoming drivers. From the Mercedes-Benz Global Media site:
[T]he next generation on the new E-Class uses a newly developed, high-resolution precision LED module as a grid light source, fitted with 84 high-performance LED chips. This is able to react even more dynamically, and the light illuminating the road is high-resolution and even more precise. In addition, the “cornering light” function can be implemented without mechanical actuators.