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Thread: Too-Bright Headlights & Fog-Lamp Questions

  1. #1
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    Default Too-Bright Headlights & Fog-Lamp Questions

    With the advent of so many SUVs and pickup trucks, nowadays, the higher placement of headlights puts them right in the eyes of (lowly?) sedan drivers. The tremendous intensity of some new lights is absolutely blinding. I don't think it's an alignment issue because so many brand new vehicles have extremely bright lights. How is this legal when incandescent wattage used to be limited to limit brightness? Any info or thoughts about this?

    Until I bought a used 2014 VW Jetta Wagon, last year, I wondered why so many drivers had the fog lights on. Low & behold, any time my headlights are on, so are the fogs. Other vehicles I've had with fogs, had switchable lights. Why the always-on "feature"?
    I'm absolutely certain that I need another flashlight.

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    Default Re: Too-Bright Headlights & Fog-Lamp Questions

    Quote Originally Posted by jayflash View Post
    I don't think it's an alignment issue because so many brand new vehicles have extremely bright lights.
    Between factory alignment and then dealer "tweaks", who knows how well they are aimed. See, for example https://www.candlepowerforums.com/vb...mp-performance

    Past that, the state requirements can be pretty weak. In California, an error of +/- 4" from level at 25' (10 cm at 7.6 m) is considered "legally acceptable" to get a "Certificate of Adjustment - Lamp Adjustment" for headlamps mounted up to 36" from the ground (see, for example, Figures 8 and 9 on Lamp 26).

    P.S. Might be more broadly seen in the Automotive sub-forum here

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    Default Re: Too-Bright Headlights & Fog-Lamp Questions

    Quote Originally Posted by jayflash View Post
    With the advent of so many SUVs and pickup trucks, nowadays, the higher placement of headlights puts them right in the eyes of (lowly?) sedan drivers. The tremendous intensity of some new lights is absolutely blinding. I don't think it's an alignment issue because so many brand new vehicles have extremely bright lights. How is this legal when incandescent wattage used to be limited to limit brightness? Any info or thoughts about this?
    Intensity limits are used to limit 'brightness'.

    However, many vehicles do not have properly aimed headlamps from the factory. Others have headlamps people have tried to adjust the beam, poorly. Still others have a trailer attached whose tongue weight is pushing the back down and changing headlamp aim.

    Until I bought a used 2014 VW Jetta Wagon, last year, I wondered why so many drivers had the fog lights on. Low & behold, any time my headlights are on, so are the fogs. Other vehicles I've had with fogs, had switchable lights. Why the always-on "feature"?
    It's not "always-on", it's switch-controlled. Push your light switch button in a click.

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    Default Re: Too-Bright Headlights & Fog-Lamp Questions

    Jayflash, did you get your combination switch figured out?

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    Default Re: Too-Bright Headlights & Fog-Lamp Questions

    I agree with Jayflash that the new SUVs and trucks can be blinding when you are coming at them in a much lower vehicle where the newer lights are really intense since they shine the eyes of lower vehicles, even when the SUV or truck lights are properly aligned. I agree that not all vehicles have properly aligned lights, or have a load in the back, but it has been like this for decades and most new vehicles have properly aligned light. The new lighting technology is just so much more intense, even when properly aligned, if the light is allot higher then the oncoming drivers head, you'll get glare in your face. There is tons of info on this including petitions attempting to ban these new intense headlights. BMW and probably other manufactures has technology (anti-dazzle) in some of their headlights that use cameras and adjusts the light to go around a vehicle in front of them so as to not blind them but still allow the driver to light up the road. This is disabled for USA vehicles since the Euro and US lighting standards are different.

    Experts at AAA said new LED headlights can be blinding and are making it harder for drivers to see.
    "Especially with vehicles sitting up higher than they used to these days, it's hitting us more in the eyes than it ever has before. It's become an issue with the lights. It's great for the person driving the car because they can see everything but not for the person the light is hitting," said Kevin Lynch, AAA car care manager.

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    Default Re: Too-Bright Headlights & Fog-Lamp Questions

    Quote Originally Posted by pungo View Post
    The new lighting technology is just so much more intense, even when properly aligned, if the light is allot higher then the oncoming drivers head, you'll get glare in your face. There is tons of info on this including petitions attempting to ban these new intense headlights.
    They said this when we moved from acetylene headlamps to electric ones with 21cp bulbs. They said it when we went from electric ones with 21cp bulbs to 32cp bulbs. And again with sealed beams, then with halogen sealed beams.

    While in some cases glare went up, the ability of the driver to see also increased. And with this "arms race" of headlamps, eventually everyone has the same (more or less) headlamp. Is the guy in the car from 1912 with 21cp bulbs at a disadvantage when sharing the road with a '53 Ford with sealed beams? Sure, and compared to his own headlamps, that '53 Ford seems to be blinding him and making his lamps seem useless. But as cars age out off the highway, the 50th-percentile headlamps are good enough to compete fairly with better headlamps and nobody is at an extreme disadvantage.

    What would help is if we had uniform state inspections including checking and correcting headlamp aim, and for people to know how their own vehicles' light switches work so they don't drive around with just DRLs because their dashboard is lit up (and therefore not be able to see where they are going or even be seen as well at night), or drive around with their fog lamps unnecessarily, increasing glare for others.

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    Default Re: Too-Bright Headlights & Fog-Lamp Questions

    Another thing I think should be a requirement is autoleveling headlights. I have been past numerous of the latest pickup trucks with LED headlights that had a load in the bed or were pulling a heavy trailer and had the rear of the truck squatted down. The headlights were shining clear over the top of my vehicle and the the intensity was so high that I had to just pull over.

  8. #8

    Default Re: Too-Bright Headlights & Fog-Lamp Questions

    Quote Originally Posted by pungo View Post
    most new vehicles have properly aligned light.
    That's not actually the case. It's begun to get better over the last few years since good aim is crucial to getting a good score on the IIHS headlight ratings, but it's still nowhere near the case that "most new vehicles have properly aligned light".

    There is tons of info on this including petitions attempting to ban these new intense headlights.
    There are tons of MISinformation on this all over the net, including out-of-order petitions guaranteed dead on arrival (if they ever arrive anywhere relevant, that is) because they are completely without technical merit, written by people who don't know what they're talking about, and, most importantly, include absolutely zero data to back their baseless claims and demands.

    if the light is allot higher then the oncoming drivers head, you'll get glare in your face.
    See here. That said, yes, today's headlamps provide a wider, more intense beam. That provides much better safety performance, but it also means, yes, more opportunities for other drivers' eyes to intersect a high-intensity portion of the beam pattern (glare). That glare exposure does not necessarily constitute a safety hazard, however.

    BMW and probably other manufactures has technology (anti-dazzle) in some of their headlights that use cameras and adjusts the light to go around a vehicle in front of them so as to not blind them but still allow the driver to light up the road.
    It's called ADB, Adaptive Driving Beam, and it's not a BMW technology. All the European makers and most or all of the Asian makers offer it in Europe and most of the rest of the world, but it's not allowed in the United States.

    Experts at AAA said new LED headlights can be blinding and are making it harder for drivers to see. "Especially with vehicles sitting up higher than they used to these days, it's hitting us more in the eyes than it ever has before. It's become an issue with the lights. It's great for the person driving the car because they can see everything but not for the person the light is hitting," said Kevin Lynch, AAA car care manager.
    I'm sure he knows quite a lot about tire rotation, checking for exhaust leaks, keeping your windshield clean and servicing your windshield wipers, deciding how often to change oil, and that kind of thing. Now, what part of being Car Care Manager makes Mr. Lynch an "expert" in the very complicated science of headlighting? The actual science on the matter, done by actual scientists, clearly demonstrates that more seeing light = more safety, despite increased glare. Drivers tend to behave safely in the presence of glare, though they will often complain, justifiably, about the discomfort it causes.

    Remember, just because it's on the internet doesn't mean it's true or correct or accurate or valid.
    Last edited by -Virgil-; 02-11-2020 at 02:15 PM.

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    Default Re: Too-Bright Headlights & Fog-Lamp Questions

    Quote Originally Posted by Alaric Darconville View Post
    The new lighting technology is just so much more intense, even when properly aligned
    They said this when we moved from acetylene headlamps to electric ones with 21cp bulbs. They said it when we went from electric ones with 21cp bulbs to 32cp bulbs. And again with sealed beams, then with halogen sealed beams.
    That is exactly what happened. And again with the first replaceable-bulb headlamps with HB1 (9004) bulbs. Every single time, the complaint has been exactly verbatim: "These new lights are a safety hazard! That intense bright blue-white light is so glaring!". Yes, although it's difficult to imagine without scoffing, people considered halogen sealed beams and 9004 RBHLs to produce an intense blue-white light (compared to the previous technology).

    While in some cases glare went up, the ability of the driver to see also increased.
    This is the key, right here. What many people don't understand (or don't like to hear) is that we are not dealing with a 1:1 safety issue here where a unit of extra seeing light and a unit of extra glare light cancel each other out, safetywise. In fact, the safety benefit of additional seeing light is massively bigger than the safety detriment of additional glare. So much so that good quality research on the subject (by UMTRI, a very reliable group of scientists in this field) concludes that safety would be improved -- meaning fewer crashes, less injury, fewer fatalities, less property damage -- if everyone used high beam after dark, even in traffic. The researchers acknowledge, however, that this would be very uncomfortable and so would not be accepted in practice.

    And with this "arms race" of headlamps, eventually everyone has the same (more or less) headlamp.
    I don't agree, at least not any more. That largely stopped being the case once the sealed beam mandate ended in 1984, though the HB1 (9004) replaceable-bulb headlamps gave performance similar to halogen sealed beams. It completely stopped being the case once the HB3-HB4 (9005-9006) systems came in 1987, and now, with everything from sealed beams to some 15 or 20 different halogen bulbs to HIDs and LEDs being allowed, there's a much wider range of headlight performance than there used to be in the past. This causes headaches for the infrastructure engineers -- they used to be able to accurately model how much light would hit (say) a retro-reflective road sign from approaching headlamps. Now they can model percentiles (25th, 50th, 75th...), but there's no longer an accurate match between the modelling and what will be experienced by the driver of any given vehicle.

    What would help is if we had uniform state inspections including checking and correcting headlamp aim, and for people to know how their own vehicles' light switches work so they don't drive around with just DRLs because their dashboard is lit up (and therefore not be able to see where they are going or even be seen as well at night), or drive around with their fog lamps unnecessarily, increasing glare for others.
    This, all the way. Unfortunately I don't see it happening. And it's going to get worse if/when the NHTSA ever permits ADB, because while today's fixed low/high beam headlamps are much more sensitive to vertical misaim in terms of seeing performance and glare than yesterday's lower-performance beams with softer cutoffs, ADB systems are hugely more sensitive to vertical and horizontal misaim.

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    Default Re: Too-Bright Headlights & Fog-Lamp Questions

    Quote Originally Posted by Magio View Post
    Another thing I think should be a requirement is autoleveling headlights.
    Absolutely right. If we can't have ADB (which really should actually be mandatory, given its huge safety benefit versus inherently inadequate low beam), we should at least have dynamic automatic leveling. That's the kind that is responsive not just to static vehicle load but also to vehicle pitch changes due to vertical road curvature and acceleration/braking. Look at Tables 1 & 2 (pages 7 & 8) in this research.

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    Default Re: Too-Bright Headlights & Fog-Lamp Questions

    Quote Originally Posted by Magio View Post
    Another thing I think should be a requirement is autoleveling headlights.
    Definitely! But remember, they can only autolevel (whether dynamically or not) correctly when the initial static aim is set correctly. Otherwise, the system will only very accurately maintain the misaim.

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    Default Re: Too-Bright Headlights & Fog-Lamp Questions

    Quote Originally Posted by -Virgil- View Post
    So much so that good quality research on the subject (by UMTRI, a very reliable group of scientists in this field) concludes that safety would be improved -- meaning fewer crashes, less injury, fewer fatalities, less property damage -- if everyone used high beam after dark, even in traffic.
    I had an experience one night on my motorcycle that drilled this home for me - I had dropped my headlight down to low beam for an oncoming vehicle. As soon as it passed, I flicked back to high beam and it instantly illuminated a deer standing by the edge of my side of the road. I slowed down and moved left in case it jumped out but fortunately it didn't.


    because while today's fixed low/high beam headlamps are much more sensitive to vertical misaim in terms of seeing performance and glare than yesterday's lower-performance beams with softer cutoffs, ADB systems are hugely more sensitive to vertical and horizontal misaim.
    How is this being addressed in Europe? Are the dealers required to have headlamp aiming equipment, and are the headlamps checked and aimed regularly (like during scheduled service)?
    Last edited by jaycee88; 02-11-2020 at 07:09 PM.

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    Default Re: Too-Bright Headlights & Fog-Lamp Questions

    Quote Originally Posted by jaycee88 View Post
    I had an experience one night on my motorcycle that drilled this home for me - I had dropped my headlight down to low beam for an oncoming vehicle. As soon as it passed, I flicked back to high beam and it instantly illuminated a deer standing by the edge of my side of the road.
    Exactly. Crashes occur disproportionately at night (small percentage of miles driven, large percentage of death/injury/property damage), and even so, it's some kind of miracle the carnage isn't worse than it is, because even with the best low beams we just cannot see anywhere near as well as we need

    How is this being addressed in Europe?
    Stringent (more or less, depending on country) vehicle roadworthiness inspections including headlamp aim have long been the norm in Europe, and it's very easy to find a shop with the correct equipment to aim lamps properly. That said, they are not without their aim problems. Their aim specifications are too low, which means their seeing distance is much too short. This is based on their long tradition of prioritizing lowest possible glare on low beam (while the US priority has long been on maximum possible seeing distance). As difficult as it might be for some to believe, the science is fully on the side of the US approach. The European argument isn't "We think the science is actually on our side", it's "Glare is not accepted in Europe", which is a philosophical argument rather than a scientific one.

    So which is the better overall safety situation? Practically difficult to answer, but what would be best would be European-frequency aim inspection and careful adjustment to US aim specs (and allowance or preferably mandate for ADB in the USA).

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    Default Re: Too-Bright Headlights & Fog-Lamp Questions

    Quote Originally Posted by Alaric Darconville View Post
    Definitely! But remember, they can only autolevel (whether dynamically or not) correctly when the initial static aim is set correctly. Otherwise, the system will only very accurately maintain the misaim.
    That's an important point, but it's not quite as universally true as it used to be. There are systems now that can determine and self-set the correct aim. They're not at all common; they might not even have been put into mass production. But the technology does exist and has been at least demonstrated.

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    Default Re: Too-Bright Headlights & Fog-Lamp Questions

    Quote Originally Posted by jaycee88 View Post
    I had an experience one night on my motorcycle that drilled this home for me - I had dropped my headlight down to low beam for an oncoming vehicle. As soon as it passed, I flicked back to high beam and it instantly illuminated a deer standing by the edge of my side of the road. I slowed down and moved left in case it jumped out but fortunately it didn't.

    How is this being addressed in Europe? Are the dealers required to have headlamp aiming equipment, and are the headlamps checked and aimed regularly (like during scheduled service)?
    In Europe, they all know how to decelerate before turning off their high beams... (No, I'm kidding, unfortunately.)
    Aiming equipment? Depends where, and who... Many dealers were recently required to get fancy modern headlamp aiming equipment that can deal with ADB to allow official roadworthiness inspections to be carried out at their premises. I wonder where the better of the "old" equipment they threw out landed: Probably in 230V & UNECE countries, which explains why apparently zero of them made it to American dealerships or garages.

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    Default Re: Too-Bright Headlights & Fog-Lamp Questions

    Quote Originally Posted by Marcturus View Post
    which explains why apparently zero of them made it to American dealerships or garages.
    It's still quite a challenge (at least near San Francisco, California) to find a shop with an optical beamsetter and the skills and desire to do the job well. While there is "Certificate of Adjustment – Lamp Adjustment" in the state, I've never found out when it might be required. Beyond that, a ±4" at 25' tolerance on aim is hardly "stringent".

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    Default Re: Too-Bright Headlights & Fog-Lamp Questions

    Quote Originally Posted by jeffsf View Post
    It's still quite a challenge (at least near San Francisco, California) to find a shop with an optical beamsetter and the skills and desire to do the job well. While there is "Certificate of Adjustment – Lamp Adjustment" in the state, I've never found out when it might be required. Beyond that, a ±4" at 25' tolerance on aim is hardly "stringent".
    There are varying tolerances based on the lamps' vertical centers, the one you describe is for lamps whose vertical center is 22-26" high. It's been ages since I've done 9th grade trigonometry, but that seems like a 1.528° variance (± 0.764°), which at the extremes could cost you quite a bit of distance vision or be very glaring to others. However, softer cutoffs mean it's harder to aim with great precision, even with good equipment and a high level of skill. Degraded lenses make aiming even more difficult due to the loss of focus.
    Last edited by Alaric Darconville; 02-18-2020 at 04:51 PM.

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    Default Re: Too-Bright Headlights & Fog-Lamp Questions

    Quote Originally Posted by -Virgil- View Post
    That said, yes, today's headlamps provide a wider, more intense beam. That provides much better safety performance, but it also means, yes, more opportunities for other drivers' eyes to intersect a high-intensity portion of the beam pattern (glare). That glare exposure does not necessarily constitute a safety hazard, however.
    If the high intensity portion of the beam pattern (glare) can intersect the oncoming driver eyes, why is that not a safety hazard for the oncoming driver since they can be partially blinded until the vehicle passes? This is especially true for tall SUV and trucks no matter how accurately the lights are adjusted, the much lower oncoming vehicle will be partially blinded due to the intensity of the newer lighting technology. That's where Adaptive Driving Beam (ADB) technology is beneficial by not directing the beam into the oncoming drivers eyes, but unfortunately that requires more expensive electronics and currently only high end vehicles have ADB which AFAIK is not even enabled for the US market.

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    Default Re: Too-Bright Headlights & Fog-Lamp Questions

    Quote Originally Posted by -Virgil- View Post

    This is the key, right here. What many people don't understand (or don't like to hear) is that we are not dealing with a 1:1 safety issue here where a unit of extra seeing light and a unit of extra glare light cancel each other out, safetywise. In fact, the safety benefit of additional seeing light is massively bigger than the safety detriment of additional glare. So much so that good quality research on the subject (by UMTRI, a very reliable group of scientists in this field) concludes that safety would be improved -- meaning fewer crashes, less injury, fewer fatalities, less property damage -- if everyone used high beam after dark, even in traffic. The researchers acknowledge, however, that this would be very uncomfortable and so would not be accepted in practice.


    <SNIP>
    Virgil,
    Can you point to this study? How recent is it?
    It seems to me that it is an older study, and doesn't take into account the blindingly intense lights of today. You see... 20 years ago, high beams may be uncomfortable when aimed into the face of oncoming traffic, but they would not necessarily be blinding. Today's lights are absolutely blinding.

    There is a fairly brightly lit intersection in a town I drive home through at night. Typically there is a stream of oncoming cars stopped at a stop sign, on a slight rise in the road, and their headlights (properly aligned) hit me directly in the eyes. I slow to about 5 mph because I might not see a pedestrian, crossing the street, in front of me.

    There are another couple of spots on the way home, that are hilly, and the road curves. In these sections, the road is very dark, and my eyes are a little dark adjusted. Often, suddenly as I approach this curve, an oncoming vehicle comes up the rise, with it's beam in my face, such, that I have to look away, and judge, that I am staying in my lane, by looking to the right hand side of my lane, for where the asphalt meets the dirt. Sometimes, the light is so blinding, that I have to hit my brakes, and am afraid, that I might be rear-ended, because the driver behind me, may also be blinded, and not see my brake lights.

    I often have a vehicle behind me on the interstate, that is literally 1/4 mile away, and its headlights, lights the interior of my cab sufficiently, that I can read a gas station receipt. I can not believe, that much light, and with that much intensity, is needed to increase safety.

    Back in the seventies, I took a driver's safety test that warned driver's: Do Not Over-drive Your Headlights. In other words, do not drive faster, than that speed, which would allow you to stop, within the distance, that you can safely see with your headlights. They also pointed to driving around blind curves. They also pointed to using low beams or fog lights, and NOT high beams, when driving in fog, AND that people have a tendency to drive faster in fog, than they should, because (they proposed) that when in fog, people lose some of their sense of speed because they can't see very far into the periphery. All this to say... people need to be cognizant to their surroundings, and not excessively speed just because they can.

    Did the researchers take into consideration that many of the fatalities, that occur at night, are related to alcohol consumption?

    It seems to me that the study you refer to is flawed. If not, does it suggest that I should increase the output of my headlights and drive with my high beams on? Does it mean that I would no longer be blinded if doing so?

    Driving blind can not be a good thing.
    Last edited by Poppy; 02-20-2020 at 09:06 PM.
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    Default Re: Too-Bright Headlights & Fog-Lamp Questions

    One interesting read is Nighttime Glare and Driving Performance, 2008, Section VII. Overall Conclusions https://www.nhtsa.gov/sites/nhtsa.do...les/811043.pdf


    Given the influence of headlamp aim on measures of visibility and glare (Akashi et al., 2008),and the frequency of mis-aim found on vehicles, more consistent vertical aim of headlamps would provide more consistent light levels toward oncoming drivers' eyes, and reduced instances where light levels are high. Periodic adjustment of headlamp aim or automatic adjustment systems could then be helpful countermeasures against glare.


    The visual needs survey tended to point to the basic conclusion that low beam headlamp beam patterns are, if not perfect, then close to optimal given their attention to controlling glare. Even though higher intensities from such headlamp patterns are probably necessary to ensure detection distances sufficient to respond to hazards at many driving speeds, drivers' intolerance for the discomfort glare from such intensities probably limits the feasibility of increasing low-beam headlamp intensity significantly. Many lines of evidence suggest that increasing the intensity of a headlamp will improve visibility for a driver and simultaneously worsen glare for other drivers.


    Adaptive headlamp systems such as the SAFS prototype evaluated through the present research program (Bullough et al., 2008) provide a possible work-around regarding the inherent conflict between visibility and glare by reducing luminous intensity only when and where other drivers are located and maintaining higher intensities for good visibility in the remaining parts of the visual scene. To be sure, such systems could be embodied in many ways other than the system developed in the present research program; for example, light emitting diodes (LEDs) could be a useful light source technology for dynamically switching or dimming parts of a beam pattern.But the results of the SAFS prototype evaluation appear to show that the basic approach has merit and can be demonstrated on moving vehicles.


    The above report also found that, for the vehicles sampled

    Thirty-six percent of the [new-vehicle sample's] VOR vehicles and 22 percent of the VOL vehicles had at least one headlamp mis-aimed by more than 0.76°.

    and
    62 percent [of the in-use sample] had at least one headlamp mis-aimed


    Toyota has apparently asked for clarification on ADB systems and, if not permissible, formal acceptance thereof. See, for example, https://www.federalregister.gov/docu...ated-equipment

    However, given the glacial speed of US headlamp regulations, I wouldn't hold your breath. Headlamp History and Harmonization https://deepblue.lib.umich.edu/bitst...MTRI-98-21.pdf is an interesting read.
    Last edited by jeffsf; 02-20-2020 at 11:32 AM.

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    Default Re: Too-Bright Headlights & Fog-Lamp Questions

    Quote Originally Posted by -Virgil- View Post
    ....good quality research on the subject (by UMTRI, a very reliable group of scientists in this field) concludes that safety would be improved -- meaning fewer crashes, less injury, fewer fatalities, less property damage -- if everyone used high beam after dark, even in traffic. The researchers acknowledge, however, that this would be very uncomfortable and so would not be accepted in practice....
    High beams always on? Sounds like a recipe for increasing nighttime road rage incidents, with resulting deaths and injuries.

  22. #22

    Default Re: Too-Bright Headlights & Fog-Lamp Questions

    Quote Originally Posted by -Virgil- View Post
    This is the key, right here. What many people don't understand (or don't like to hear) is that we are not dealing with a 1:1 safety issue here where a unit of extra seeing light and a unit of extra glare light cancel each other out, safetywise. In fact, the safety benefit of additional seeing light is massively bigger than the safety detriment of additional glare. So much so that good quality research on the subject (by UMTRI, a very reliable group of scientists in this field) concludes that safety would be improved -- meaning fewer crashes, less injury, fewer fatalities, less property damage -- if everyone used high beam after dark, even in traffic. The researchers acknowledge, however, that this would be very uncomfortable and so would not be accepted in practice.
    Maybe I just don't get it, but I can't understand how it would be safer if everyone drove around with their high beams on? On some of the narrow back country roads I drive, sometime an idiot will be coming toward me with their high beams on in an SUV and even though I flash my high beams a few times and they don't turn them off. A few times, even though I'm looking toward the shoulder, I've had to come to a craw since I can barely see the edge of the road. How is that safer?

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    Default Re: Too-Bright Headlights & Fog-Lamp Questions

    Apparently, driving with your high beams always on is popular in China.

    https://www.bbc.com/news/blogs-news-...where-37847056

    Police in southern China are punishing drivers who dazzle other road users with full-beam headlights by making them stare into the lights for a minute, it's reported.

    The force faced criticism for a similar initiative in 2014, but nonetheless decided to start it up again on Tuesday. This time around, the reaction has been largely positive.

    Shenzhen Traffic Police posted photos of the campaign in action on their official Weibo account. "Tonight we are carrying out punishments using a high beam," the post reads. It's racked up 87,000 likes and been shared 93,000 times. The photos show people sitting directly in front of a car with its headlights on.

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    Default Re: Too-Bright Headlights & Fog-Lamp Questions

    Quote Originally Posted by jeffsf, quoting from a document View Post
    Given the influence of headlamp aim on measures of visibility and glare (Akashi et al., 2008),and the frequency of mis-aim found on vehicles, more consistent vertical aim of headlamps would provide more consistent light levels toward oncoming drivers' eyes, and reduced instances where light levels are high. Periodic adjustment of headlamp aim or automatic adjustment systems could then be helpful countermeasures against glare.
    Yes, we need both of those -- periodic headlamp aim adjustment and automatic adjustment systems. This isn't a breakthrough finding or anything; read the link in post #10 of this thread.

    low beam headlamp beam patterns are, if not perfect, then close to optimal
    This is a good example of where contextual awareness and knowledge are required to correctly read and understand scientific writing. If this is read the same way you'd read a newspaper, it looks like it's saying low beams are pretty close to ideally suited to their task. That is not what it means. It means the writer's interpretation of the data they're working with is that U.S.-specification low beams strike the right balance between seeing and glare (which is the definitional intent of a low beam). This is not a new or groundbreaking thing; that has been the U.S. position for as many years as the European position has been that the European-specification low beams strike the right balance. The U.S. position is backed by a great deal of science; the European position is backed more by philosophical stance. As far as our discussion here on this board goes, it doesn't really move the ball any -- it's exactly where we were at post #13 of this thread. :-)

    Even though higher intensities from such headlamp patterns are probably necessary to ensure detection distances sufficient to respond to hazards at many driving speeds, drivers' intolerance for the discomfort glare from such intensities probably limits the feasibility of increasing low-beam headlamp intensity significantly. Many lines of evidence suggest that increasing the intensity of a headlamp will improve visibility for a driver and simultaneously worsen glare for other drivers.
    Post #9 of this thread.

    Adaptive headlamp systems such as the SAFS prototype evaluated through the present research program (Bullough et al., 2008) provide a possible work-around regarding the inherent conflict between visibility and glare by reducing luminous intensity only when and where other drivers are located and maintaining higher intensities for good visibility in the remaining parts of the visual scene.
    Post #8 of this thread.

    Thirty-six percent of the [new-vehicle sample's] VOR vehicles and 22 percent of the VOL vehicles had at least one headlamp mis-aimed by more than 0.76° and 62 percent [of the in-use sample] had at least one headlamp mis-aimed
    Also not new or groundbreaking...yes (still, again, still, again) we don't care about headlight aim in North America, and while today's headlamps are easier to aim, they are also more sensitive to misaim. The two go hand-in-hand.

    Toyota has apparently asked for clarification on ADB systems
    The Toyota petition, back in 2015 or so, floated the idea that ADB could be considered legal within the existing text of FMVSS 108. That idea didn't find favor with NHTSA.

    However, given the glacial speed of US headlamp regulations, I wouldn't hold your breath.
    That's pretty much the long and short of it. Even Canada, where the vehicle standards and regulations are generally kept in close alignment with the US rules, got tired of waiting and permitted ADB. NHTSA's proposal for an ADB specification was a mess, essentially saying automakers could put ADB systems on their cars as long as the systems meet all existing high and low beam requirements and limits, which, in effect, means no ability to do what ADB systems are designed to do. NHTSA also proposed a completely unworkable test regime for ADB systems. Nobody seems to know why their proposal was such a freakshow; nobody wanted this. It's not like NHTSA had competing asks and they had to pick and choose or split the difference or compromise, etc. Pretty much everyone (car industry, lighting industry, safety researchers and academics...) is in surprisingly uniform consensus about what an ADB system should do and how it should work...except for NHTSA.

    Headlamp History and Harmonization https://deepblue.lib.umich.edu/bitst...MTRI-98-21.pdf is an interesting read.
    Yes, it is, for getting a pretty good background handle on the divergencies between US and "everywhere else" practice, though its publication date means everything in the last 23 years is absent.

  25. #25

    Default Re: Too-Bright Headlights & Fog-Lamp Questions

    Quote Originally Posted by Poppy View Post
    Virgil, Can you point to this study? How recent is it?
    It's not a single study, it's a pretty large amount of research over many years, by a pretty good list of highly capable, very reputable researchers. Yes, I could point to many of the individual papers and studies, but I have to say your post here doesn't make me want to do so. In fact, it makes me want to specifically not go get the references and post them here, and I'll let your words do most of the work in explaining why:

    It seems to me that it is an older study
    Did the researchers take into consideration that many the fatalities, that occur at night, are related to alcohol consumption?
    It seems to me that the study you refer to is flawed.
    You literally have no idea what you're talking about -- you guessed/assumed it's a single study, you guessed/assumed it's old and therefore obsolete and invalid, you threw alcohol in there because you guessed/assumed it's relevant to this discussion and you guessed/assumed the researchers must have not factored that in, and then you "concluded", based on your pile of guesses, that "the" study is flawed, and claimed victory...all without having read a single bit of the large amount of research. You seem to believe guesses and assumptions and opinions are just as valid as scientific research, but that is not the case.

    If you were really curious, if you really wanted to learn and understand, you wouldn't have made this attempt to debunk from a position of pure ignorance, you would have asked thoughtful questions. Instead you demonstrated that you aren't interested in getting informed or understanding the science -- you "know" what you (think you) know, you "understand" what you (think you) understand, you have your (baseless) opinions and guesses and assumptions and what you (think you) understand of what you (think you) remember from fifty years ago, you have your misinformed, unrealistic prescriptions for how to make everything better, and by gummit, you're not about to let any stupid old study change your mind. Now, why on earth would anyone else want to do any homework or footwork for you? You have the same access to the UMTRI and RPI-LRC research libraries as everybody else, including me. When I first started accessing those resources I had to figure out how to search effectively, just like everyone else. When I find materials relevant to whatever topic I'm looking into, I have to use their bibliographies to follow the research thread and find the referenced prior research, just like everyone else.

    You see...
    This professorial affectation is really the cherry on top. Protip: when you're in a forum or a room populated with subject matter experts, and you start throwing around uninformed opinions and guesses and assumptions, they will be detected as such immediately -- even if you put "You see..." before them.

    20 years ago, high beams may be uncomfortable when aimed into the face of oncoming traffic, but they would not necessarily be blinding. Today's lights are absolutely blinding.
    This is so completely wrong, from start to finish, that it's almost entertaining.

    There are another couple of spots on the way home, that are hilly, and the road curves. In these sections, the road is very dark, and my eyes are a little dark adjusted.
    Yet another incorrect guess-assumption-opinion.

    Often, suddenly as I approach this curve, an oncoming vehicle comes up the rise, with it's beam in my face, such, that I have to look away, and judge, that I am staying in my lane, by looking to the right hand side of my lane, for where the asphalt meets the dirt. Sometimes, the light is so blinding, that I have to hit my brakes, and am afraid, that I might be rear-ended, because the driver behind me, may also be blinded, and not see my brake lights.
    You think you know what you can and can't see. You think you know when you're blinded. In fact, you know neither. This is not specific to you in particular; it applies to all human beings: we mistakenly think we know how well we can see. It's an unfortunate quirk of how our visual systems and our minds work.

    I often have a vehicle behind me on the interstate, that is literally 1/4 mile away, and its headlights, lights the interior of my cab sufficiently, that I can read a gas station receipt. I can not believe, that much light, and with that much intensity, is needed to increase safety.
    Reality exists as it exists regardless of what anyone thinks they can't believe. Beliefs don't have a legitimate place in this discussion.

    Back in the seventies, I took a driver's safety test that warned driver's: Do Not Over-drive Your Headlights. In other words, do not driver faster than you would be able to stop, within the distance, that you can safely see with your headlights.
    Fine advice -- and yet, virtually every driver outdrives their low beams on a routine basis. Telling them to stop is pointless; that's not going to happen. We have to deal with the world as it is, not as we wish it were or think it should be.

    They also pointed to using low beams or fog lights, and NOT high beams, when driving in fog, AND that people have a tendency to drive faster in fog, than they should, because (they proposed) that when in fog, people lose some of their sense of speed because they can't see very far into the periphery
    So here we have a presentation of what you think you remember from over four decades ago, including what you think you recall of somebody else's speculation.

    All this to say... people need to be cognizant to their surroundings, and not excessively speed just because they can.
    People outdrive their low beams. The only way to stop it would be to rigidly enforce a 35-mph (dry) 30-mph (rain/snow) 15-mph (fog, heavy rain, heavy snow) speed limit. That's not going to happen, and so the solution will have to be technological. For the time being, that largely means lighting.


    does it suggest that I should increase the output of my headlights
    Too vague a question to answer usefully, but I think you were probably asking rhetorically.

    and drive with my high beams on?
    That would be illegal. Nobody has proposed that everyone should drive with their high beams on. The science of the matter is that if everyone drove with high beams, there would probably be fewer crashes and pedestrian-hits, but there are many, many steps between that and a recommendation that everyone should drive with high beams. Even if you asked this question disingenuously, I can't entirely blame you for it; most people have no training in how to read and understand scientific writing, and one of the clickbait industry's tactics is to put complex, narrow scientific findings under simplistic, general headlines.

    Does it mean that I would no longer be blinded if doing so?
    Again with the disingenuous rhetorical question -- this time with a premise that's faulty because it's based on one of your beliefs that isn't based in reality, but rather in what you think you perceive.

    Driving blind can not be a good thing.
    Nobody has suggested otherwise.
    Last edited by -Virgil-; 02-20-2020 at 10:13 PM.

  26. #26

    Default Re: Too-Bright Headlights & Fog-Lamp Questions

    Quote Originally Posted by pungo View Post
    Maybe I just don't get it, but I can't understand how it would be safer if everyone drove around with their high beams on
    There would likely be far fewer pedestrian-hits -- pedestrian-hits are the biggest group of traffic-related deaths, and most of them occur after dark, mostly because they were not adequately lit by the low beams. This does not mean everything would be better if everyone drove with high beams. It wouldn't solve every problem, it would create some new problems (the obvious one being a lot more discomfort), and there would probably be an increase in some other kind of bad event, perhaps such as run-off-the-road incidents. However, the net effect would probably be positive; there would have to be a HUGE increase in the number of run-off-roads to come close to the number of pedestrian-hits, and the percentage of run-off-roads that is fatal or severely injurious is much lower than that percentage of pedestrian-hits, so in all likelihood overall safety would be improved.

    "Unintended consequences" is usually assumed to mean bad ones, but there can be good ones, too. For example, right now we know relatively little about the cumulative effect of prolonged and repeated glare on driver performance. That doesn't mean we know little, just that we know less about it than we do about immediate or shorter-term repeated or extended glare. If everyone started driving around with high beams, we would probably learn a lot about the effect on driver performance of long-term extended/repeated glare.

    All of this is academic now; ADB effectively gives high-beam seeing with low-beam glare (given appropriately-written regulations and appropriate attention to headlamp aim), thus finally resolving the seeing/glare conflict that has existed in headlighting for about a hundred years.


    sometime an idiot will be coming toward me with their high beams on in an SUV and even though I flash my high beams a few times and they don't turn them off. A few times, even though I'm looking toward the shoulder, I've had to come to a craw since I can barely see the edge of the road. How is that safer?
    I'm not trying to be a smartass, but you slowed down, didn't you...!

    One tragic effect of the present state of education, politics, and news media in the United States is that many people think all opinions are equally valid, few people are equipped to sort facts from opinions internally or externally, few people are trained in basic scientific thinking and so tend to be more comfortable with what they consider "common sense", and many people think "science" is just a word for some person's or group's self-interested opinions.

    If the high intensity portion of the beam pattern (glare) can intersect the oncoming driver eyes, why is that not a safety hazard for the oncoming driver since they can be partially blinded until the vehicle passes?
    The short answer is we're not blinded (partially or completely), we're made uncomfortable. It feels like "HELP I'M BLIND O MY GOD I CAN'T SEE GET THAT LIGHT OUT OF MY EYES", but that's not the actual reality of the situation. It cannot be stated often enough: there is often a large disconnect between how safe we are and how safe we feel.
    Last edited by -Virgil-; 02-20-2020 at 09:56 PM.

  27. #27
    Flashaholic* Poppy's Avatar
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    Default Re: Too-Bright Headlights & Fog-Lamp Questions

    Virgil,
    Thank you for your response.
    I apologize for my lack of clarity in my comments, those that led you to believe that I was disingenuous. I did not intend dis-ingenuity, but rather would like to learn from you, in that you have an obvious (to me) greater depth of knowledge of the subject at hand, than I.

    I drive a 2008 Mercury Grand Marquis with halogen lamps. My daughter has a Mazda CX5 with lights that are MUCH brighter than mine. Her seat is higher than mine. In my car the glare is terrible. In her car, bad, but not so bad. I have electric seats and raised my seat to the max, and that actually made an improvement, but not enough. So my question from a scientific point of view is this: if my headlights were brighter, would I perceive less glare?

    Thank you for the links you posted above, I'll look through them and get back to you.
    Last edited by -Virgil-; 02-20-2020 at 10:14 PM.
    My Grand Kids call me Poppy

  28. #28

    Default Re: Too-Bright Headlights & Fog-Lamp Questions

    Quote Originally Posted by Poppy View Post
    I apologize for my lack of clarity in my comments, those that led you to believe that I was disingenuous. I did not intend dis-ingenuity
    Apology accepted, and I in turn apologize if I reacted too harshly. When someone comes up with a tone of voice indicator system for on-screen words, they'll make a billion dollars (and they'll deserve it).

    I drive a 2008 Mercury Grand Marquis with halogen lamps. My daughter has a Mazda CX5 with lights that are MUCH brighter than mine.
    OK, so the questions at hand sound more like "Hey, how come her lights are so much brighter? How can I make mine better?". Is that along the lines of what you want to know?

    my question from a scientific point of view is this: if my headlights were brighter, would I perceive less glare?
    Yes, though we have to be careful what we mean by "brighter headlights" -- if it means more light and longer/wider seeing because we've done appropriate upgrades that preserve or improve the beam focus, then good/yes. If it means we've hacked the lights in one of a bunch of ways ("LED bulbs", "HID kits", remove the bulb shield, misaim the lamps, etc) then bad/no. With that proviso out of the way: there wouldn't be less glare, there'd be the same amount, but it would feel less debilitating because your own lights would be doing a better job for you. If you think about this for a few minutes, it might occur to you that this is consistent with the finding that if everyone used their high beams all the time, everyone would see better. We're talking about the same thing, just within different limits. The underlying principle is the exact same: the safety benefit from extra seeing light is greater than the safety drawback of extra glare light. Sounds simple, but it's not; there are many interconnected and seemingly contradictory effects at work. For example: it takes a lot more light to increase seeing ability than it does to increase glare. Another example: the placement of light within the beam most likely to provoke favorable opinions of a set of headlamps is least helpful to safety performance/actually helping the driver see. The subject really is very, very complex. For the set of questions you're asking, probably the best single-source document is SAE J2829, which goes into very well-written detail about how the tradeoffs work between seeing and glare, how seeing light increases interact with glare increases, glare characteristics of other cars' lights versus seeing light characteristics of your car's lights, etc. It's an expensive document, but while I haven't looked for this one specifically, it seems almost anything can be found if you look around/ask around on the internet these days.

    An '08 Grand Marquis's headlamps can be upgraded pretty significantly. Suggest you talk to Daniel Stern (search Daniel Stern Lighting and you'll find his site)

  29. #29
    Flashaholic* Poppy's Avatar
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    Default Re: Too-Bright Headlights & Fog-Lamp Questions

    Quote Originally Posted by -Virgil- View Post
    Apology accepted, and I in turn apologize if I reacted too harshly. When someone comes up with a tone of voice indicator system for on-screen words, they'll make a billion dollars (and they'll deserve it).

    ok we're good.
    OK, so the questions at hand sound more like "Hey, how come her lights are so much brighter? How can I make mine better?". Is that along the lines of what you want to know?

    No. I wanted to know if the additional brightness would make the perception of glare less. As sunlight during the day does when someone drives with their headlights on. During the day the glare is much less perceived as a hazard.
    Yes, though we have to be careful what we mean by "brighter headlights" -- if it means more light and longer/wider seeing because we've done appropriate upgrades that preserve or improve the beam focus, then good/yes. If it means we've hacked the lights in one of a bunch of ways ("LED bulbs", "HID kits", remove the bulb shield, misaim the lamps, etc) then bad/no. With that proviso out of the way: there wouldn't be less glare, there'd be the same amount, but it would feel less debilitating because your own lights would be doing a better job for you.

    THANK YOU that answers my question above.

    If you think about this for a few minutes, it might occur to you that this is consistent with the finding that if everyone used their high beams all the time, everyone would see better. We're talking about the same thing, just within different limits. The underlying principle is the exact same: the safety benefit from extra seeing light is greater than the safety drawback of extra glare light. Sounds simple, but it's not; there are many interconnected and seemingly contradictory effects at work. For example: it takes a lot more light to increase seeing ability than it does to increase glare. Another example: the placement of light within the beam most likely to provoke favorable opinions of a set of headlamps is least helpful to safety performance/actually helping the driver see.

    This is counter intuitive. Primarily because it is too vague without a beam profile. Example: a laser can create devastating glare, actual blindness, but not provide any usable seeing ability for the driver.

    The subject really is very, very complex. For the set of questions you're asking, probably the best single-source document is SAE J2829, which goes into very well-written detail about how the tradeoffs work between seeing and glare, how seeing light increases interact with glare increases, glare characteristics of other cars' lights versus seeing light characteristics of your car's lights, etc. It's an expensive document, but while I haven't looked for this one specifically, it seems almost anything can be found if you look around/ask around on the internet these days.

    An '08 Grand Marquis's headlamps can be upgraded pretty significantly. Suggest you talk to Daniel Stern (search Daniel Stern Lighting and you'll find his site)

    [/QUOTE]

    Thanks so much.
    I found his site and will drop him a note.
    Poppy
    Last edited by Poppy; 02-20-2020 at 11:03 PM.
    My Grand Kids call me Poppy

  30. #30

    Default Re: Too-Bright Headlights & Fog-Lamp Questions

    Quote Originally Posted by Poppy View Post
    If you think about this for a few minutes, it might occur to you that this is consistent with the finding that if everyone used their high beams all the time, everyone would see better. We're talking about the same thing, just within different limits. The underlying principle is the exact same: the safety benefit from extra seeing light is greater than the safety drawback of extra glare light.
    This is counter intuitive. Primarily because it is too vague without a beam profile. Example: a laser can create devastating glare, actual blindness, but not provide any usable seeing ability for the driver.
    It is counterintuitive, but it's not too vague; we don't need to account for things like lasers because we are speaking only about headlight beams.

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