the lights, please

If you’ve driven on U.S. roads in the last few years or so, chances are pretty good that at one time or another you’ve experienced the scourge of blinding headlights.

For the longest time I suspected it was only me that was bothered, that I was simply getting older and my eyes more sensitive to light at night time. But as it turns out, I’m not alone in thinking the lights are too damn bright, as the steady stream of news articles over the past few years and adjacent commentary make clear.

So what’s happening here?

The fact is that headlights have gotten progressively better over the last century. The earliest headlights in the late 19th century when the first automobiles were introduced were lanterns powered by oil or gas. These earliest headlights illuminated the road better than nothing, but they were not that powerful.

Shortly thereafter came electric headlights, which were a marginal improvement. What really revolutionized lighting was the invention of the sealedbeam headlight shortly before WWII. This produced a more focused beam of light that helped illuminate the road better than anything that had come before. Improvements continued with halogen lighting in the later part of the 20th century, followed by the introduction of xenon-based high intensity discharge (HID) technology and most recently LED headlights. However, that’s just part of the story. The other key factor involves vehicle design itself. As the U.S. automobile market has become saturated with ever bigger vehicle sizes, the roads are now filled with larger SUVs and trucks, all of which have front ends that sit higher o the ground. Consequently, the headlight placement in these vehicles is also higher up, and thus more of the intensity of the light is at eye-level of other drivers on the road, leading to the blinding headlight phenomenon.

But wait, there’s still more! Perhaps the most important factor involves an old federal law on automobile headlights in the U.S. The law states that all vehicles in the U.S. must have both a low-beam and a high-beam headlight. The problem is that the solution to excessively bright headlights lies in so-called adaptive headlight technology, which uses a single beam that’s software controlled to respond to the surroundings, making the beam stronger and more intense when it needs to be and dialing it back in other instances.

Thus, while adaptive headlight technology has been standard on newer vehicles across the world, it has not been legal to build it into vehicles in the U.S. because of the law requiring two separate beams. The good news is that thanks to the Infrastructure Bill passed last year, there is a provision that rescinds the two-beam requirement and opens the door for adaptive headlight technology to be incorporated in vehicles in the U.S.

The lesson here may be how many di erent factors play a role in solving a problem. From the design of the headlights (including the software used in the new adaptive technology) to the vehicle design itself, to the role of government regulations and the need to revisit them as our technology continues to evolve; it takes a great amount of coordination to get it all right in the end. And save our collective eyeballs. DW