Figure 11 is a diagram of Hella, a leading manufacturer of LED headlights for the automotive industry. It is important to note that these diagrams do not show the uneven spatial energy emitted by the diode. These diagrams give the false impression that the LED light is uniform when it is not. No matter how the LED light is reflected or refracted by the optics, the light will always come out of the headlight with extremely intense and uneven energy that far exceeds NHTSA regulations for maximum light intensity due to the luminance of about 100,000,000 nit of the source beam. This means that LED headlights do not comply with FMVSS-108 and are therefore not approved for use in motor vehicles. It is important to know the laws of your state, province or country before you fully commit to using LED lights or headlights. It`s just as important that you do your research to find out what is DOT compliant and what is not. Today, we`re going to look at what is and isn`t considered DOT compliant in a broader sense, and look at some real-world examples. It may say the obvious, but your car`s headlights are a safety feature, and not all headlights are created equal. For some time, automakers have been adding powerful LED headlights to their high-end offerings, but in most cases, their cheaper cars — and especially cheaper trim variants — are cluttered with much dim lighting. But sometimes a commuter wants to see more of where they`re going when the sun goes down.
Finally, they are looking for a solution, starting with their local auto parts business. But plugging aftermarket LED headlights into OEM enclosures designed for traditional halogen units results in dangerous glare for oncoming drivers. While LEDs can provide more intense light at an upper end of the spectrum, most aftermarket units also create a dangerous condition. LEDs emit light from a flat surface. The fact that the surface is not curved radically changes the spatial distribution of light energy. FMVSS-108 has no evidence of flat-surfaced transmitters, as LEDs and lasers have just been invented and there was certainly no concept that LEDs could ever be made powerful enough to be used as vehicle headlights. The industry and regulation that grew in the 1960s, 1970s, 1980s, and 1990s evolved around the assumption that the light source produced uniform energy in all directions, that the spectral distribution of light resembled that of a candle, and that the light did not flash. At the time when LEDs appeared in vehicle headlights, regulators, engineers, and automotive industry executives recognized little recognition that anything related to LED light required a change in regulations and measurement techniques, or that LED light could be toxic or dangerous. The color of your headlights is also subject to the law. You must have yellow or white headlights, no matter where you live. LED chip manufacturers accurately measure the light density emitted by LED chips in the laboratory.
LED chip manufacturers regularly publish their achievements and by 2018, chip manufacturers had exceeded 100,000,000 nits of peak luminance. Compare 100,000,000 nits emitted by an LED chip with a human comfort level of 300 nits. The extreme light density emitted by an LED chip helps explain why LED headlights cause eye pain and damage. Headlights that cause eye damage and pain violate the Motor Vehicle Safety Act and are therefore illegal. If you`re not so sure, look for reviews of their products on Amazon, eBay, YouTube, and forums for the vehicle you`re looking for. Typically, projectors under $100 that you see on marketplace sites like Amazon or eBay won`t meet dot regulations and will likely perform very poorly. So if LED headlights are illegal, and tens of thousands of people are demanding that LED headlights be abolished, and if LED headlights are life-threatening, why is nothing being done? How did we get here? Figure 11 shows a Honda vehicle equipped with original LED headlights and daytime running lights. None of these LED lights comply with U.S. federal regulations and are likely to result in injury or death, in violation of the Motor Vehicle Safety Act. It is technically illegal to put them in a car in accordance with federal motor vehicle safety standards. However, you can buy LED headlights in your local store and install them yourself.
Most people won`t notice it or care. The problem is that LEDs are extremely bright and often dazzle oncoming drivers, which is considered both rude and dangerous. HID lights are a safer and more legal alternative to LEDs, which should be considered instead. But the choice is ultimately yours. FMVSS-108 does not address the issue of spectral power distribution. The conclusion when FMVSS-108 was written in 1967 was that the light source of a projector had a spectral power distribution similar to the two numbers above and that energy distribution was not an issue to consider. There are other components that are more specific to the type of headlights or bulbs you`re using, but that`s usually what you should look for. February 27, 2022 – The Soft Lights Foundation sends a letter to Ford informing them that LED headlights are dangerous and illegal. Another good indicator to know if the headlights you want to buy are of good quality is when they say “SAE Certified”: to really accurately measure the distribution of photons, we need to choose a very high resolution detector system at the scale of the picometer or femtometer. In practice, this also means that we use a precision measuring device in a laboratory and only have to measure under near-field conditions at a distance of about 1 micrometer from the surface of the chip.
Once the detector has a sufficiently high resolution and the detector is close enough to the source chip, the detector shows the distribution of photons and how most photons are grouped in a very small space. The fault of the engineers who certify the LED headlights is to use software that is only accurate at the micron scale and uses far-field data captured 100 feet from the source. Figure 10 shows precision measurements at the femtometer scale under near-field conditions. “Currently, there are no replaceable LED headlights that meet federal safety standards. NHTSA is aware of illegal modernization kits sold to consumers and is working closely with U.S. Customs and Border Protection to prevent shipments from entering the U.S. with these non-compliant headlights. NHTSA is continually looking for new technologies with the potential to improve road safety. Figure 8, how automakers use a detector to count photons emitted by a tungsten/halogen headlight.