Talk:Headlamp/Archive 1

SAE/ECE

 * Perhaps the section regarding SAE/ECE should be expanded (featuring more examples of pros and cons). I could try to create some images describing the various light patterns produced by respective standard. Otherwise I agree that the article could be improved in regards to structure etc. Scoo 11:09, 30 November 2005 (UTC)


 * Nowtimes, there are really no more examples of pros and cons. The only salient differences between present-day SAE and ECE headlamp beam philosophy are those stated. The project of creating images comparing SAE vs. ECE should be approached with caution to avoid presenting misleading information, because the differences are no longer categorical or readily apparent when observing the beam pattern projected on a wall or roadway. With recent regulatory convergence, there are many SAE beams that look very much like ECE beams, and there are some ECE beams that look very much like SAE beams. There remain differences, of course, but these are on a fairly arcane, esoteric level that could not properly be explicated without *extremely* lengthy discourse probably beyond the scope of a Wiki entry.


 * In addition, photographs of beam patterns are usually by their nature misleading, while drawings are not adequate to convey meaningful information. Comparative isoscans are what is needed. I may have some that can give a clear visual impression of the traditional/classic form of ECE vs. SAE low beams—give me a few days to dig them up. Finally, the "This article needs to be restructured!" comment you're referring to was made *before* the article was restructured and expanded, and ancillary articles added where appropriate.

--Scheinwerfermann 20:09, 16 December 2005 (EST)


 * Also, I was thinking that a delineation of current regulations may be pertinent to the section dealing with the SAE. Valerie 20:10, 29 November 2006 (UTC)


 * What do you mean by "a delineation of current regulations"? --Scheinwerfermann 22:07, 29 November 2006 (UTC)

Info added/corrected
Greetings, Duk and all. I've gone through and fleshed-out the chronological, regulatory and design discussions in these articles, as well as nuking a few errors of fact, terminology and chronology. Scheinwerfermann 03:11, 1 August 2005 (UTC)


 * Looks good, I'm planning on adding some more schematics. --Duk 03:22, 1 August 2005 (UTC)

Also, Daytime Running Lamp really needed its own article, so I wrote it. Scheinwerfermann 04:19, 1 August 2005 (UTC)

Problems w/projector headlamp schematic
Eek. Problems with this image!

The "Light/Dark" indications just ahead of the condenser lens are reversed.
 * I dont understand what you mean, dark is above the cutoff line. I think the schematic is correct here. Imagine the Hella scematic you reference with more rays traced. --Duk 05:07, 1 August 2005 (UTC)

The shield/shade/slide in a projector headlamp blocks the *lower* area of the reflector from direct view by the lens. The beam image produced by the lamp assembly is reversed (left/right and up/down), so the presence of the shield at the lower half of the lamp manifests in the beam pattern as darkness *above* the bright beam pattern.
 * That's why the Dark note is with the *above* arrow.--Duk 17:37, 1 August 2005 (UTC)

Nope, the schematic is not correct, because the "Dark/Light" arrows are much too close to the beam unit. At that close distance, the beam image is still reversed. I will take some photos of disassembled projectors for you (and their projected beams) to demonstrate. Give me a couple of days.
 * Would it make more sense to you if I added Dark (oncomming drivers eyes) and Light (road). This will help distinguish the distance (see the lens optic schematic). --Duk 17:37, 1 August 2005 (UTC)

See This link and This link. Scheinwerfermann 04:54, 1 August 2005 (UTC)

Also, "solenoid" is the correct spelling, and "dim/brights" should be replaced by "if present".
 * add "if present" not replace?

done--Duk 17:37, 1 August 2005 (UTC)

Yep, works much better now, good idea on "oncoming drivers' eyes" and "roadway".

I've moved the signal lights info to their own article (see Automotive lighting ) which incorporates the orphan Turn Signal article. Still need to flesh out the taillamp section of Automotive Lighting and write up the Fog and Driving lamp articles.


 * Also added info to the Dual-beam headlamp section discussing different ways of obtaining a high and a low beam from a 2-filament bulb in a reflector; still need to add info on BiXenon headlamps (movable reflectors, movable bulbs, movable projector cutoff shields).


 * Added article on Federal Motor Vehicle Safety Standard 108 as a basis for a more general discussion of automotive lighting regulation. Linked Headlamp and Automotive lighting and Daytime running lamp articles to it. Provided external links to US, Canadian and international ECE regulations.


 * Edited and incorporated separate sequential turn signal article into turn signal section of Automotive lighting.


 * Edited and incorporated separate Xenon HID headlamp article into headlamp technology section of Headlight. (

Headlamp has another meaning too
Headlamp has another meaning too which is a lighting device fastened to the head and used in mining, caving, climbing etc. Please see Petzl. There is link to this page but with different intention. Any suggestion on how to include this new topic? Neshatian 09:19, 31 January 2006 (UTC)


 * Adding a new entry to disambiguation page is the right thing to do. An incoming link from Night Orienteering can be made. Kslotte (talk) 11:59, 14 June 2008 (UTC)


 * Proposed description for this entry: a mobile lightening fastened to the head for outdoor activities Kslotte (talk) 12:05, 14 June 2008 (UTC)

chronology question...
before I dive in and correct the article, can someone refresh my memory? I thought that sealed beams were required starting in 1940, not 1937. In fact I'm fairly certain that that's so, as IIRC that was the main difference between 1939 and 1940 Ford models.

Good catch, now fixed. Scheinwerfermann 21:15, 9 March 2006 (EST)

History section
Great article with lots of valuable info, but I think some of the data in the history section could be in new sections, like the halogen bit. If history was a quick overview chronology, I think it would help the user navigate this wealth of data. PLawrence99cx 12 March 2006 (EST)


 * This is Wikipedia, so you know whatto do: be bold!


 * Atlant 12:43, 12 March 2006 (UTC)

LED Headlights
The article talks about the large variations in LED output with respect to temperature. Is this for circuits with a constant voltage source? What if the LEDs have a current controlled power supply? I believe most high power or exotic automotive LED applications have current controlled sources. --Duk 00:23, 15 April 2006 (UTC)

Various strategies
Smart power sourcing is one strategy employed to cope with LEDs' output changes with ambient temperature. Current control, PWM and other means are used, and for the most part they are effective. However, the extreme nature of the temperature/output dependency causes there to be efficacy and/or lifespan penalties involved. Scheinwerfermann 01:15, 15 April 2006 (UTC)

LED Flux Ratings
High-flux LED are almost always binned at 25˚C rather than 15˚C, so the comparison in the article can be somewhat deceiving. Also, even a 30% decrease in output is only a noticeable and not significant change in apparent brightness, due to the human eye's logarithmic perception of luminous intensity.96.236.129.113 (talk) 16:22, 16 March 2008 (UTC)

Fog lamps
I reverted Skittle's insertion of fog lamp in the list of names for high beam headlamps. Fog lamps do need to be discussed, and I'm working on an article about them, but they are functionally not the same as driving lamps, high beams, main beams, low beams, passing beams, or anything else. Fog lamps are known only by that name. Scheinwerfermann 21:51, 1 May 2006 (UTC)

Interesting; I look forward to reading about that. On my car I only have normal 'dipped' lights and fog lights, as far as I know. I've always assumed they were the same as main/high beams as that's what they were used for, now I wonder if a) my car is poo b) my driving instructor knew nothing about cars :-) Skittle 03:03, 2 May 2006 (UTC)
 * For a quicky primer on the topic, go see
 * this site.Scheinwerfermann 03:16, 2 May 2006 (UTC)

AC or DC?
I searched the document to see if the headlights of a car uses AC or DC, and I couldn't find what I was looking for.

Apparently, the current is DC. --mimithebrain 00:53, 18 June 2006 (UTC)


 * Cars today definitely use "12 volts" DC (the system uses a 12V battery but actually operates at about 14V when the engine is running). Because of the ever-increasing demand for electrical power in cars, there's a move afoot to raise the system voltage to 42V (with a 36 volt battery), but even then, you may still find 12V used for many ordinary accessories such as the various incandescent lamps that might still be used and aftermarket radios.


 * Atlant 01:06, 18 June 2006 (UTC)

Hidden and pop-up headlamps
I've corrected the language regarding hidden and pop-up headlamps, and moved the list of vehicles with hidden or pop-up headlamps to the relevant article, Hidden headlights. Tomorrow I'll tackle the inaccuracies in the body text of that article. Scheinwerfermann 04:01, 17 July 2006 (UTC)

Article Title

 * The following discussion is an archived debate of the . Please do not modify it. Subsequent comments should be made in a new section on the talk page. No further edits should be made to this section. 

move to Headlamp. Extraordinary Machine 01:03, 3 August 2006 (UTC)

Headlamp or Headlight? While it is common for the two terms to be used interchangeably in colloquial speech, headlampis the technically correct term for the device itself. All regulations and technical specifications worldwide refer to headlamps, and not to "headlights". All manufacturers of such devices consider themselves makers of headlamps, not "headlights". "Headlight" properly refers to the light itself, produced and distributed by the headlamp(s). This is certainly a distinction that would not be honored in everyday conversation or informal writing, but we're writing an encyclopedia here, so precision counts. Talking about "sealed beam lights" or "round lights" or "rectangular lights" or "replaceable-bulb lights" might be acceptable in a stylistic analysis in which the devices are significantly only by dint of their existence; such usage, though, is technically improper in a discussion of lighting devices. This article's improper title has been a low-level irritant for quite some time; 193.202.109.254's attempt to standardize on one term, even though s/he picked the wrong one, is the impetus for this requesting a pagemove to correct that impropriety. Scheinwerfermann 16:48, 24 July 2006 (UTC)
 * Wrong one? Why wrong? '193' chose to standardize on the article name; ''headlight' MH 11:32, 30 July 2006 (UTC)


 * Oppose. Merriam, Webster, and I think headlight is preferable. I could be convinced to reconsider if other sources with significant authority were cited. — Knowledge Seeker দ 03:47, 25 July 2006 (UTC)
 * Switched to neutral support . Scheinwerfermann has demonstrated abundant usage of headlamp; in the absence of anything to the contrary, the formal title should probably be used. I would like to see a proper authority cited in the article explaining the terminology, if possible. — Knowledge Seeker দ 05:43, 26 July 2006 (UTC)
 * Here y'go. The author is a longtime appointed member of the US National Academy of Sciences Transportation Research Board's Visibility Committee, and while the language of this post to the lighting engineering newsgroup is phrased rather informally, and leaves out some detail, it does seem to contain the statement you're/we're looking for (2nd to last paragraph). I will see if a more detailed version of the same info is available in a more formal location, but this is a start, do you agree? Scheinwerfermann 03:45, 27 July 2006 (UTC)
 * Excellent. This is the sort of citation that belongs in the article; of course, a more formal citation, if it exists, would be preferable. If this is the source you end up using, I'd mention it in a footnote, as I previously described to you. — Knowledge Seeker দ 06:54, 27 July 2006 (UTC)
 * Citations: University of Michigan Transportation Research Institute Library, one of the world's most complete collections of motor vehicle equipment and safety research. Search keyword headlamp* and note the many, many pages of results, all of which deal with the devices themselves. Then go back and search keyword headlight*, and note the many, many pages of results, all of which deal with the light beam or the general situation of light in front of an automobile. Rensselaer Polytechnic Institute's Lighting Research Center, another of the world's major topical libraries. First search headlamp, then search headlight. Compare results. Also, full contents of Hella Automotive Lighting Master Catalogues, 1978 through 2006 inclusive. Valeo Automotive Lighting Systems Full Range Catalogues, 1973 through 2005 inclusive. Bosch Vehicle Lighting and Signalling catalogues, 1984 through 2004 inclusive, which will probably be hard for you to obtain, but you can view those companies' websites: Hella USA Hella Europe Hella South Africa Valeo international AL-Automotive Lighting Co. (vehicular lighting joint venture between Bosch + Magneti-Marelli) North American Lighting Koito Ichikoh Samlip Visteon TYC Genera Maxzone Depo Stanley Electric, these comprise virtually all the world's significant headlamp producers, and they all call them "headlamps". Furthermore, US Federal Motor Vehicle Safety Standard 108 always refers to the devices as headlamps and to the overall system or the light beam as headlighting system, headlighting requirements, etc. Likewise, Canada Motor Vehicle Safety Standard 108 makes the same distinction. And ECE Regulations number 1, 5, 8, 20, 31, 37, 45, 48, 56, 57, 72, 76, 82, 98, 99, 112, and 113 all refer to headlamps and not to "headlights". Same with Australian Design Rules 46 and 75. Same with the UK Ministry of Transport. Same with South Africa's regulatory agency. So, that covers virtually all the world's production, research and regulation of the devices. Scheinwerfermann 05:04, 25 July 2006 (UTC)


 * Oppose . Isn't headlight American English and headlamp Commonwealth English?  If so, the article should retain its current title per Manual_of_Style: follow "the spelling style preferred by the first major contributor".   Note:  My understanding is that, while the entire fixture is called a headlight in the USA, the bulb is called a headlamp.  Hence, some of the links above are a little disingenuous since they are references to the bulbs and not the entire headlight/lamp.  If this is wrong, please post evidence or reasoning. - AjaxSmack 05:41, 25 July 2006 (UTC)


 * Incorrect. This is not a spelling-preference issue. There is no difference between American and Commonwealth English usage of the terms, and the bulb itself is in no country or context called a "headlamp". Since you are making the claim of that usage, it would be up to you, please, to supply citations. I have provided a superabundance of evidence to support my assertions. Scheinwerfermann 13:40, 25 July 2006 (UTC)


 * No, I have no firsthand knowledge of this and have withdrawn my vote. - AjaxSmack 05:02, 26 July 2006 (UTC)


 * Tentative support. The SAE spec titles use mostly "headlamps" (please correct me if I'm wrong). My car's manual (american made) uses "headlamp". Encyclopedia Britannica uses both in various articles (it favors headlight in the automotive electric article). --Duk 05:34, 26 July 2006 (UTC)


 * Correct, SAE makes the same distinction as US Federal Motor Vehicle Safety Standards and Canada Motor Vehicle Safety Standards: The devices are called headlamps, the system is called a headlighting system and the general notion of a specific kind of light in front of a car is called headlighting requirements. Scheinwerfermann 04:19, 27 July 2006 (UTC)


 * Support - Both terms are pretty much interchangable nowadays, but since Scheinwerfermann has presented a good deal of citations, and since both the US and Canadian governments use "headlamp" instead of "headlight", I will support the page move, even though I'm more partial to "headlight". --ApolloBoy 04:33, 28 July 2006 (UTC)


 * Weak support - for consistency and what Apolloboy said. Though I too am more partial to "headlight". MH 09:25, 28 July 2006 (UTC)


 * Weak support - Although headlamp is the correct technical term I'm hard-pressed to give more than weak support because of the overwhelming use of headlight as the layman's term. For consistency's sake it should be changed. --93JC 20:20, 28 July 2006 (UTC)


 * Weak support, as per ApolloBay. – Axman (☏) 11:08, 30 July 2006 (UTC)


 * Oppose per policies/guidelines, since "headlight" is the more commonly used term. -Hit bull, win steak(Moo!) 16:12, 30 July 2006 (UTC)
 * Ample evidence has been provided that "headlamp" is the more commonly used term. Can you please support your assertion to the contrary? Scheinwerfermann 16:41, 30 July 2006 (UTC)
 * The examples you cited are all official or specialized sources, which do not accurately reflect common usage; instead, look at the Google book results for the two. There are 9,450 examples using "headlamp" and 25,500 examples using "headlight",, an extremely substantial difference. From a random sampling, it's true that a small fraction of the "headlight" results refer to the beam, but it seems like an equal percentage of the "headlamp" results refer to the lamp on the front of a miner's helmet.
 * Moreover, I've never met anyone in my entire life (until now) who referred to them as headlamps, and at least several hundred who call them "headlights". I'm apparently not alone in this, either, from the remarks of earlier commenters. As such, it fails the common sense test. -Hit bull, win steak(Moo!) 17:50, 30 July 2006 (UTC)


 * "Common usage" is not an appropriate measuring stick here. We are not writing a dictionary or holding a popularity contest, we're writing an encyclopedia and striving for accuracy and precision. That being the case, official terminology (as you acknowledge it to be) is correct. Scheinwerfermann 18:15, 30 July 2006 (UTC)


 * I respectfully disagree with Hit bull, win steak. Regarding the most commonly used term;
 * First of all, an example, "The Bends" has 1.4million google hits, "Decompression sickness" has 330K google hits, the wikipedia article uses the less common, more correct term, "Decompression sickness". (I'm sure there are lots more examples out there)
 * Second, headlight might be more common in Google searches, but not in relevant usage, like automobile owner manuals and official regulations. Also, some of the Google meanings are referring to the light emitted, not the mechanical assembly (bulb reflector, etc...) where headlamp is the correct term.
 * Third, it's pretty clear that everyone in the industry, including regulatory and technical organizations use headlamp.
 * (Just out of curiosity) Hit bull, win steak, what does your automobile manual use? Mine uses headlamp. Also, I know several people (not in the auto industry) that use headlamp in common speech. --Duk 18:21, 30 July 2006 (UTC)
 * Please note that this was Google Books search results, rather than just plain google hits. The distinction is a pretty important one, since the citations are in things that actually constitute reliable sources, as opposed to random-ass webpages. If you want the pure google webpage count, it's 10.4 million for headlight, and 3.5 million for headlamp. As for the car thing, I can't check right now, although you've got me curious. I had ankle surgery a week ago Friday, and I won't get fitted for a walking boot until Wednesday. -Hit bull, win steak(Moo!) 18:42, 30 July 2006 (UTC)
 * Sorry to hear about your ankle, hope it gets better soon. With regards to reliable sources as opposed to random-ass web pages - I completely agree. And when the quality of sources are considered, headlamp wins hands down. See Scheinwerfermann's links and notes above. Regulatory, industrial and technical references use headlamp for the mechanical assembly. --Duk 19:22, 30 July 2006 (UTC)


 * Support. It was my anon IP that originally started the article. I support renaming to headlamp. -- IlyaHaykinson 18:32, 30 July 2006 (UTC)
 * The above discussion is preserved as an archive of the debate. Please do not modify it. Subsequent comments should be made in a new section on this talk page. No further edits should be made to this section.

Headlamp steering section
I suggest a section on headlamp steering. I saw an ad recently touting this feature, I think in a Lexus or BMW or something. This technology goes back a long way, but I don't know of specific models that have incorporated it. The basic idea is that as the steering wheel is turned, a mechanical or electrical linkage is connected to actuators that rotate the headlamps. The idea is that the headlight follows the road better. --Lenehey 15:50, 2 October 2006 (UTC)


 * Leheney- See sections 5.2 and 5.3 of the article, which deal with older mechanical and newer electronic directional headlamps, respectively. --Scheinwerfermann 16:04, 2 October 2006 (UTC)

HID HEADLAMPS
"An HID headlamp requires a ballast. The ballast converts the 12 volts used in automotive electrical systems to the several thousand volts required to strike and maintain the arc."

This is not entirely correct, several thousand volts is required to strike the arc and ionise the gas which then becomes highly conductive. The voltage then drops to several tens of volts, enough to maintain the arc.

62.49.106.67 16:12, 17 October 2006 (UTC)Martin


 * You know what to do: be bold and correct the article!


 * Atlant 16:27, 17 October 2006 (UTC)

Dispersion patterns
This article needs a graphic that shows headlight dispersion patterns. I don't know enough or I'd make an illustration myself. --Duk 05:22, 2 November 2006 (UTC)

Fake HID Bulbs
First of all, let me say, what a great article. As a former GM employee, I was very impressed with all the historic information as well as the comparison of ECE and SAE standards and the history of headlamp design.

I like the fact that you mentioned that installed Japanese home-market headlamps on US cars can be dangerous. A lof of the so-called "rice racers" think that anything that is Japan market is obviously better than the "dumbed down" US version (when in fact, often times the parts are different for a reason).

A lot of unscrupulous manufacturers are offering standard 12V H1 bulbs as "HID" or "Xenon projector" bulbs, when in fact, they are simply standard headlamp bulbs dipped in a blue gel to provide a bluish hue that mimics (not very effectively) the HID "look". I have read many discussion on these bulbs, and some sources indicate that this blue "look" can actually be dangerous, as it decreases the output of light.

To compensate, some manufacturers use higher wattage bulbs and then claim they put out more light, which they do, but more glare. As you might imagine, they are not DOT approved.

I also wonder if the discussion of the cost of HID bulbs is useful. I have these on one car (2002 BMW X5) and while they are interesting, I am not sure they are an improvement. The owner's manual claims they will last the life of the car (BMW claims the same thing about their transmission fluids, with the deabte being what "life of the car" exactly comprises). However, they do note that turning them on and off rapidly can shorten the service life severely (why is this?). These appear to be the levelling kind, as they come on in a "dipped" position and then physically aim upward after a short warmup period. I am told these units can cost upwards of $1000 to replace when they burn out, which begs the question, what is the point of these lamps, other than to provide the manufacturer with a lucrative crash-parts business? (The same could be said of the bespoke composite headlamp in general).

Speaking of dipping headlamps, Mercdes used to have HELLA units in the old W123 that would manually "dip" using a vacuum-operated dashpot. I was fortunate enough to have a greymarket Mercedes with this feature (well, this feature restored, after obtaining the correct parts from overseas). The dipping feature was, however, not for a high/low beam function, but instead to compensate for headlight aim as the car was loaded. Needless to say, they were not legal in the USA, but still quite fun to play with.

Anyway, the whole automotive lighting article is excellent.

Joe Patent (talk) 23:35, 1 February 2009 (UTC)

Reflector Optics Picture
I was wondering if everyone agrees we change the picture on that section? The Jeep Liberty in the picture is really dirty and the picture seems slight out of focus or blurred to me. I'll try and take a better picture off my Volvo XC90 and if everyone agrees replace the current picture with it. Payam81 07:38, 9 January 2007 (UTC)

Re-name
Yes, I did miss that discussion, my apologies. Honestly, I didn't expect it to be such a contentious issue. I must say that in fixing the links and redirects (which were a mess before I did anything) showed me that throughout wikipedia there was no common usage; headlight and headlamp were used just about 50-50, frequently both in the same article, sometimes in the same link (i.e. headlight ).

I have no strong feelings in this; I was going through tool stubs when cap light lead me here. If there is consensus behind "headlamp" than all the links should be tracked down and harmonized. Pjbflynn 00:08, 16 February 2007 (UTC)


 * There's consensus that headlamp is the proper name and therefore the correct title of the article. However, the common usage of headlight means it should certainly exist as a redirect. There is no need to track down links and redirect or pipe them to headlamp; redirects are a feature, not a bug. --DeLarge 11:56, 16 February 2007 (UTC)

Section: Usage/etiquette
At the risk of being perceived to have violated WP:OWN, which is not my intent, I have removed the usage/etiquette section. Wikipedia is not a how-to manual, and the information provided was wholly centric to the US. Vehicle lighting usage varies widely by custom and regulation throughout the world, and while a section dealing with different customs and regulations might be a valuable addition to the article, a US-biased list of "do"s and "don't"s doesn't fit so well. Furthermore, none of the assertions in the section was backed up with references, and while I and others have lagged severely in citing the sources from which the existing information was drawn, several of the key assertions in this deleted section were unsupportable by any US or international jurisdictional regulation. --Scheinwerfermann 22:37, 2 July 2007 (UTC)


 * Really? "[W]holly centric to the US"?  I know I specifically mentioned the United States in one spot, but I figured at least half of it would apply in various places around the world.  If not then, well, I'd hate to ever drive anywhere else in the world (not that I'm all that happy driving here much of the time -- in fact, I thought to add the info due to a discussion elsewhere regarding common courtesy on the roads.  I thought I'd add what I knew about my own experiences).  Yes, unfortunately a lot was vague.  Some customs aren't defined in regulation and aren't even easy to find written on the Internet or anywhere else, so it might just turn into a messy can of worms anyway.  However, I thought some of it was new information that answered some basic questions.  The article discusses high and low beams a lot, but when are they used?  What indication does a driver have that the vehicles lights are operating?  Etc.  Well, anyway, it wasn't intended to be the end-all, be-all section for this topic.  I thought what I wrote could be just a start at a new section, or could get divided up and put in various parts of the article or other areas of Wikipedia.  I hope some portions can come back eventually. &mdash;Mulad (talk) 23:48, 2 July 2007 (UTC)


 * Yeah...most of what was said regarding light flashing, jurisdictional rules, etc. was much more specific to the US than you might've realised. For example, did you know that in a significant number of places round the world, the vehicle's front position lamps (we say "parking lamps"), and not the headlamps, are used when driving at night in town? True. Not as many as used to be the case, but still plenty of them. Also, DRLs are not mandatory in the US, so while owners of vehicles equipped with headlamp-based DRLs cannot use some of the traditional headlamp signals to communicate with other drivers, this is not yet a dead practice in the US as it largely is in Canada and other countries where DRLs are ubiquitous. Note that the general usage principles are discussed in the sections on low beam and high beam headlamps. --Scheinwerfermann 04:36, 3 July 2007 (UTC)

Regulations
I actually came to this article looking for information on which Canadian provinces require driving with headlights during the day, if any. It would be useful to add or link to information on various regulations like this around the world. -- Beland 02:22, 3 August 2007 (UTC)


 * See Daytime running lamp. Automatic daytime running lights (not necessarily headlamps) are Federally required throughout Canada on all new vehicles made since 1/1/90. Beyond that, Wikipedia isn't really the right place for province-by-province lists of rules of the road. --Scheinwerfermann 03:02, 3 August 2007 (UTC)


 * I did read that article, but it doesn't answer my question, which has to do with conventional headlights being required to be turned on during the day. This is the case on some streches of road in the U.S. which are prone to fog.  The article doesn't need such a detailed list, but it would be nice to have a pointer, or at least a summary of regulations around the world.  Looking at the previous talk section, it seems that all interesting information on usage and regulations that everyday people could relate to has been removed, whereas boring and obscure facts like that LEDs at -12 °C (10 °F) emit up to 160% of their 16 °C (60 °F) rated output, have been left in.  This seems sad.  Documenting driving conventions is sociologically interesting. -- Beland 03:20, 3 August 2007 (UTC)


 * Documenting driving conditions and presenting necessarily-lengthy lists of local usage regulations just really isn't within the scope of the article, I don't think. I could certainly be wrong. Perhaps we ought to get some other opinions and guidance on the matter. The information you consider "interesting" was removed largely due to inaccuracy and bad fit. The temperature/output characteristics of LEDs are central to their use in headlamp applications, your boredom notwithstanding. --Scheinwerfermann 03:54, 3 August 2007 (UTC)