Too-Bright Headlights & Fog-Lamp Questions

jayflash

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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"?
 

jeffsf

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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/showthread.php?417410-IIHS-test-of-headlamp-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
 

Alaric Darconville

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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.
 

pungo

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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.
 

Alaric Darconville

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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.
 

Magio

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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.
 

-Virgil-

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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.
 
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-Virgil-

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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.
 

-Virgil-

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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.
 

jaycee88

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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)?
 
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-Virgil-

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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).
 

-Virgil-

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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.
 

Marcturus

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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.
 

jeffsf

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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".
 

Alaric Darconville

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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.
 
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pungo

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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.
 

Poppy

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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.
 
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jeffsf

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One interesting read is Nighttime Glare and Driving Performance, 2008, Section VII. Overall Conclusions https://www.nhtsa.gov/sites/nhtsa.dot.gov/files/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/doc...s-reflective-devices-and-associated-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/bitstream/handle/2027.42/49367/UMTRI-98-21.pdf is an interesting read.
 
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