Headlight Regulations and Requirements

January 8th, 2010

Modern headlamps are electrically operated, positioned in pairs, one or two on each side of the front of a vehicle. A headlamp system is required to produce a low and a high beam, which may be achieved either by an individual lamp for each function or by a single multifunction lamp. High beams (called “main beams” or “full beams” or “driving beams” in some countries) cast most of their light straight ahead, maximizing seeing distance, but producing too much glare for safe use when other vehicles are present on the road. Because there is no special control of upward light, high beams also cause backdazzle from fog, rain and snow due to the retroreflection of the water droplets. Low beams (called “dipped beams” in some countries) have stricter control of upward light, and direct most of their light downward and either rightward (in right-traffic countries) or leftward (in left-traffic countries), to provide safe forward visibility without excessive glare or backdazzle.

Low beam

E-code dipped/low beam

Asymmetrical low beam illumination of road surface — right-traffic beam shown

Low beam (dipped beam, passing beam, meeting beam) headlamps provide a distribution of light designed to provide adequate forward and lateral illumination with limits on light directed towards the eyes of other road users, to control glare. This beam is intended for use whenever other vehicles are present ahead. The international ECE Regulations for filament headlamps[4] and for high-intensity discharge headlamps[5] specify a beam with a sharp, asymmetric cutoff preventing significant amounts of light from being cast into the eyes of drivers of preceding or oncoming cars. Control of glare is less strict in the North American SAE beam standard contained in FMVSS / CMVSS 108.[6]

High beam

European E-code high/full beam

Symmetrical high beam illumination of road surface

High beam (main beam, driving beam, full beam) headlamps provide a bright, centre-weighted distribution of light with no particular control of light directed towards other road users’ eyes. As such, they are only suitable for use when alone on the road, as the glare they produce will dazzle other drivers. International ECE Regulations permit higher-intensity high-beam headlamps than are allowed under North American regulations.[7]

Compatibility with traffic directionality

Most low-beam headlamps are specifically designed for use on only one side of the road. Headlamps for use in left-traffic countries have low-beam headlamps that “dip to the left”; the light is distributed with a downward/leftward bias to show the driver the road and signs ahead without blinding oncoming traffic. Headlamps for right-traffic countries have low beams that “dip to the right”, with most of their light directed downward/rightward. Within Europe, when driving a vehicle with RH-traffic headlamps in a LH-traffic country or vice versa for a limited time (as for example on vacation or in transit), it is a legal requirement to adjust the headlamps temporarily so that the wrong-side hot spot of the beam does not dazzle oncoming drivers. This may be achieved by adhering blackout strips or plastic prismatic lenses to a designated part of the lens. Many tungsten (pre-halogen) European-code headlamps made in France by Cibié, Marchal, and Ducellier could be adjusted to produce either a left- or a right-traffic low beam by means of a two-position bulb holder. More recently, some projector-type headlamps can be made to produce a proper left- or right-traffic beam by shifting a lever or other movable element in or on the lamp assembly.

Because wrong-side-of-road headlamps blind oncoming drivers and do not adequately light the driver’s way, and blackout strips and adhesive prismatic lenses reduce the safety performance of the headlamps, most countries require all vehicles registered or used on a permanent or semipermanent basis within the country to be equipped with headlamps designed for the correct traffic-handedness. North American vehicle owners sometimes privately import and install Japanese-market (JDM) headlamps on their car in the mistaken belief that the beam performance will be better, when in fact such misapplication is quite hazardous and illegal.[8]

Use in daytime

Main article: Daytime running lamp

Some countries require automobiles to be equipped with automatic daytime running lamps (DRL), which are intended to increase the conspicuity of vehicles in motion during the daytime. DRL may consist of the manual or automatic illumination of the low beams at full or reduced intensity, or the high beams at reduced intensity, or may not involve the headlamps at all. Countries requiring DRL include Albania, Bosnia and Herzegovinia, Canada, Colombia, Denmark, Estonia, Finland, Hungary, Iceland, Israel, Kosovo, Latvia, Lithuania, Macedonia, Norway, Poland, Republic of Moldova, Romania, Slovenia, Czech Republic and Sweden.

Construction, performance, and aim

There are two different beam pattern and headlamp construction standards in use in the world: The ECE standard, which is allowed or required in virtually all industrialised countries except the United States, and the SAE standard that is mandatory only in the US. Japan formerly had bespoke lighting regulations similar to the US standards, but for the left side of the road. However, Japan now adheres to the ECE standard. The differences between the SAE and ECE headlamp standards are primarily in the amount of glare permitted towards other drivers on low beam (SAE permits much more glare), the minimum amount of light required to be thrown straight down the road (SAE requires more), and the specific locations within the beam at which minimum and maximum light levels are specified.

ECE low beams are characterised by a distinct horizontal “cutoff” line at the top of the beam. Below the line is bright, and above is dark. On the side of the beam facing away from oncoming traffic (right in right-traffic countries, left in left-traffic countries), this cutoff sweeps or steps upward to direct light to road signs and pedestrians. SAE low beams may or may not have a cutoff, and if a cutoff is present, it may be of two different general types: VOL, which is conceptually similar to the ECE beam in that the cutoff is located at the top of the left side of the beam and aimed slightly below horizontal, or VOR, which has the cutoff at the top of the right side of the beam and aimed at the horizon.[9]

Proponents of each headlamp system decry the other as inadequate and unsafe: U.S. proponents of the SAE system claim that the ECE low beam cutoff gives short seeing distances and inadequate illumination for overhead road signs, while international proponents of the ECE system claim that the SAE system produces too much glare.[10] Comparative studies have repeatedly shown that there is little or no overall safety benefit to either SAE or ECE beams; the two systems’ acceptance and rejection by various countries is based primarily on inertial and philosophical grounds.[9],[11]

In North America, the design, performance and installation of all motor vehicle lighting devices are regulated by Federal and Canada Motor Vehicle Safety Standard 108, which incorporates SAE technical standards. Elsewhere in the world, ECE internationalised regulations are in force either by reference or by incorporation in individual countries’ vehicular codes.

US laws required sealed beam headlamps on all vehicles between 1940 and 1983, and other countries such as Japan, United Kingdom and Australia also made extensive use of sealed beams. In most other countries, and in the US since 1984, replaceable-bulb headlamps predominate.

Headlamps on new vehicles must produce white light, according to both ECE and SAE standards. Previous ECE regulations also permitted selective yellow light, which from 1936 until 1993 was required on all vehicles registered in France. Yellow headlamps are no longer required anywhere, but remain permitted in France, Belgium, The Netherlands, Switzerland, Japan, New Zealand, and some other countries.

Headlamps must be kept in proper alignment (or “aim”). Regulations for aim vary from country to country and from beam specification to beam specification. US SAE headlamps are aimed without regard to headlamp mounting height. This gives vehicles with high-mounted headlamps a seeing distance advantage, at the cost of increased glare to drivers in lower vehicles. ECE headlamps’ aim angle is linked to headlamp mounting height. This gives all vehicles roughly equal seeing distance and all drivers roughly equal glare.[12]

Headlamp. (2010, January 6). In Wikipedia, The Free Encyclopedia. Retrieved 21:49, January 7, 2010, from http://en.wikipedia.org/w/index.php?title=Headlamp&oldid=336224700

History of Headlights

January 7th, 2010

History of automotive headlamps

One of the first optic headlamp lenses, the Corning Conaphore. Selective yellow “Noviol” glass version shown.

1917 advertisement for the Corning Conaphore headlamp lens shown above.


The earliest headlamps were fueled by acetylene or oil and were introduced in the late 1880s. Acetylene lamps were popular because the flame was resistant to wind and rain. The first electric headlamps were introduced in 1898 on the Columbia Electric Car from the Electric Vehicle Company of Hartford, Connecticut, and were optional. Two factors limited the widespread use of electric headlamps: the short life of filaments in the harsh automotive environment, and the difficulty of producing dynamos small enough, yet powerful enough to produce sufficient current.[2] “Prest-O-Lite” acetylene lights were offered by a number of manufacturers as standard equipment for 1904, and Peerless made electrical headlamps standard in 1908. In 1912, Cadillac integrated their vehicle’s Delco electrical ignition and lighting system, creating the modern vehicle electrical system.

“Dipping” (low beam) headlamps were introduced in 1915 by the Guide Lamp Company, but the 1917 Cadillac system allowed the light to be dipped with a lever inside the car rather than requiring the driver to stop and get out. The 1924 Bilux bulb was the first modern unit, having the light for both low (dipped) and high (main) beams of a headlamp emitting from a single bulb. A similar design was introduced in 1925 by Guide Lamp called the “Duplo”. In 1927, the foot-operated dimmer switch was introduced and became standard for much of the century. The last vehicle with a foot-operated dimmer switch was the 1991 Ford F-Series. Foglamps were new for 1938 Cadillacs, and their 1954 “Autronic Eye” system automated the switch between high and low beams.

The standardised 7 in (178 mm) round sealed beam headlamp was introduced in 1940, and was soon required for all vehicles sold in the United States. Britain, Australia and other Commonwealth countries, as well as Japan, also made extensive use of 7 in. sealed beams. With some exceptions from Volvo and Saab, this headlamp size format was never widely accepted in continental Europe, leading to different front-end designs for each side of the Atlantic for decades.

The first halogen headlamp for vehicle use was introduced in 1962 by a consortium of European bulb and headlamp makers. Halogen technology increases the efficacy (light output for given power consumption) of an incandescent light bulb and eliminates blackening of the bulb glass with usage. These were prohibited in the US, where non-halogen sealed beam lamps were required until 1978. Starting that year, sealed beams became available with halogen bulbs inside. These halogen sealed beams remain available, 25 years after replaceable-bulb headlamps returned to the US in 1983.

High-intensity discharge systems were introduced in 1991’s BMW 7-series. European and Japanese markets began to prefer HID headlamps, with as much as 50% market share in those markets, but they found slow adoption in North America. 1996’s Lincoln Mark VIII was an early American effort at HIDs, and was the only car with DC HIDs.

Design & style

Beyond the engineering, performance and regulatory-compliance aspects of headlamps, there is the consideration of the various ways they are designed and arranged on a motor vehicle. Headlamps were round for many years, because that is the easiest shape for parabolic reflector manufacture.

Headlamp styling outside of the United States, pre-1983

European-market aerodynamic glass-covered steering headlamps retrofitted on a US-market 1968+ Citroen DS

There was no requirement in Europe for headlamps of standardised size or shape. Automakers were free to design their lamps to whatever shapes and sizes they wished, as long as the lamps met the engineering and performance requirements contained in the applicable European safety standards. That design freedom permitted the development of rectangular headlamps, first used in 1961.

Rectangular headlamp with Selective yellow bulb on Citroën Ami 6

Developed by Cibié for the Citroën Ami 6 and by Hella for the German Ford Taunus, they were prohibited in the United States where round lamps were required until 1975. Another early headlamp styling concept involved conventional round lamps faired into the car’s bodywork with aerodynamic glass covers, such as those on the 1961 Jaguar E-Type.

Headlamp styling in the United States, 1940–1983

In 1940, a consortium of state motor vehicle administrators standardised upon a system of two 7 in (178 mm) round sealed beam headlamps on all vehicles — the only system allowed for 17 years. A system of four round lamps, rather than two — one high/low and one high-beam 5+34 in (146 mm) sealed beam on each side — was introduced in 1957 by Cadillac, Chrysler and Nash on some of their car models in states that permitted the new system, and other American marques followed suit when all states permitted quad lamps in 1958. These lamps had some photometric advantages, particularly on high beam, but the primary advantage was the styling novelty permitted by the use of two small rather than one large lamp per side of the vehicle. The freedom was not absolute, however. Auto stylists such as Virgil Exner carried out design studies with the low beams in their conventional outboard location, and the high beams vertically stacked at the centreline of the car. No such designs reached volume production. Most cars had their headlights in pairs side by side on each side of the car. Some Oldsmobiles had a parking light in the middle of each pair.

Stacked headlight on a 1966 American Motors Ambassador 990

Also popular was an arrangement in which the two headlamps on each side were stacked, low beams above high beams. Nash used this arrangement in the 1957 model year. Pontiac used this design starting in the 1963 model year; American Motors, Ford, Cadillac and Chrysler followed two years later. Also in the 1965 model year, the Buick Riviera had concealable stacked headlamps. The Mercedes-Benz W100, W108, W111, and W112 models sold in America used this arrangement because their home-market composite lamps were illegal in the US. The British firm Alvis and the French firm Facel Vega also used this setup for some of their cars, as did Nissan in Japan.

In the late 1950s and early 1960s, Lincoln, Buick, and Chrysler arranged the headlamps diagonally by placing the low-beam lamps outboard and above the high-beam lamps. Certain British cars used a less extreme diagonal arrangement, with the inboard high-beam lamps placed only slightly lower than the outboard low-beam units. The 1965 Gordon-Keeble, Triumph Vitesse and Bentley S3 Continental used such an arrangement. [3]

In 1968 when Federal auto equipment and safety regulations were initiated, the requirement for two large or four small round sealed beams was codified, thus freezing headlamp design for many years. At the same time, the new regulations prohibited any decorative or protective element in front of the headlamps whenever the headlamps are switched on. Glass-covered headlamps, used on e.g. the Jaguar E-Type, pre-1968 VW Beetle, 1965 Chrysler and Imperial models, Porsche 356, Citroën DS and Ferrari Daytona were no longer permitted and vehicles had to be imported with uncovered headlamps for the US market. This change meant that vehicles designed for good aerodynamic performance could not achieve it for the US market.

When Federal Motor Vehicle Safety Standard 108 was amended in the early 1970s to permit rectangular headlamps, these were placed in horizontally-arrayed or vertically-stacked pairs. By 1979, the majority of new cars in the US market were equipped with rectangular lamps. Again, the US permitted only two standardised sizes of rectangular sealed-beam lamp: A system of two 200 by 142 mm (7.9 by 5.6 in) high/low beam units corresponding to the existing 7-inch round format, or a system of four 165 by 100 mm (6.5 by 3.9 in) units, two high/low and two high-beam, corresponding to the existing 5+34 in (146 mm) round format.

International headlamp styling, 1983 to present

In 1983, granting a 1981 petition from Ford Motor Company, the 44-year-old US headlamp regulations were amended to allow replaceable-bulb, nonstandard-shape, architectural headlamps with aerodynamic lenses that could for the first time be plastic. This allowed the first U.S.-market car since 1939 with replaceable bulb headlamps – the 1984 Lincoln Mark VII. These composite headlamps were sometimes referred to as “Euro” headlamps, since aerodynamic headlamps were common in Europe. Though conceptually similar to European headlamps with nonstandardised shape and replaceable-bulb construction, these headlamps conform to the SAE headlamp standards of US Federal Motor Vehicle Safety Standard 108, and not the internationalised European safety standards used outside North America. Nevertheless, this change to US regulations largely united headlamp styling within and outside the North American market.

In the late 1990s, round headlamps returned to popularity on new cars. These are generally not the discrete self-contained round lamps as found on older cars (certain Jaguars excepted), but rather involve circular or oval optical elements within an architecturally-shaped housing assembly.

Hidden headlamps

Main article: Hidden headlamps

Pop up headlamps on a Mazda 323F

Hidden headlamps were introduced in 1936, on the Cord 810. They were mounted in the front fenders, which were smooth until the lights were cranked out, each with its own small dash-mounted crank. They aided aerodynamics when the headlamps were not in use, and were among the Cord’s signature design features.

Many notable cars used this feature, but no current volume-produced car models use hidden headlamps, because they present difficulties in complying with pedestrian-protection provisions recently added to international auto safety regulations, and because the mechanisms are costly and heavy. Hidden headlamps require one or more vacuum-operated servos and reservoirs, with associated plumbing and linkage, or electric motors, geartrains and linkages to raise the lamps to an exact position to assure correct aiming despite ice, snow and age. Some early hidden headlamps, such as those on the Saab Sonett III, used a lever-operated mechanical linkage to raise the headlamps into position. Current market demands place a premium on vehicles’ aerodynamic performance with lamps off and on, further reducing the attractiveness of pop-up headlamps. In addition, recent ECE regulations contain standards regarding protuberances on car bodies to minimise injury to pedestrians struck by cars.

Some hidden headlamps themselves do not move, but rather are covered when not in use by panels designed to blend in with the car’s styling. When the lamps are switched on, the covers are swung out of the way, usually downward or upward, for example on the 1992 Jaguar XJ220. The door mechanism may be actuated by vacuum pots, as on some Ford vehicles of the late 1960s through early 1980s such as the 1967-1969 Mercury Cougar, or by an electric motor as on various Chrysler products of the middle 1960s through late 1970s such as the 1966-1967 Dodge Charger.

Headlamp. (2010, January 6). In Wikipedia, The Free Encyclopedia. Retrieved 21:49, January 7, 2010, from http://en.wikipedia.org/w/index.php?title=Headlamp&oldid=336224700

Wikipedia Definition of a Headlamp?

January 7th, 2010

A headlamp is a lamp, usually attached to the front of a vehicle such as a car, with the purpose of illuminating the road ahead during periods of low visibility, such as darkness or precipitation.

While it is common for the term headlight to be used interchangeably in informal discussion, headlamp is the technically correct term for the device itself, while headlight properly refers to the beam of light produced and distributed by the device.

Headlamp. (2010, January 6). In Wikipedia, The Free Encyclopedia. Retrieved 21:41, January 7, 2010, from http://en.wikipedia.org/w/index.php?title=Headlamp&oldid=336224700

Why Headlamp Restoration

January 7th, 2010

The reason this blog is dedicated to headlight restoration is because a majority of the population looking for information on headlights are doing so because there headlights are faded and they need to be restored or replaced.  My mission is to find the very best resources for you to restore or replace your headlights.

Headlight vs. Headlamp

January 7th, 2010

You may wonder what the difference is between a headlight and a headlamp.  The answer is nothing.  Technically headlamp is the correct word to use, but I prefer headlight because that’s what most people recognize.  The headlight is the actual beam of light that shines from your headlamp. 

You will notice that I say headlight, even though I know it is not the technically correct term.

Who Am I ?

January 7th, 2010

My name is Jay Barett. I have been in the automotive industry my entire life.  My current employment has me traveling to Asia a few times a year to source automotive headlights and inspect headlight manufacturers facilities.  Because of this some would consider me to be a headlight expert.  I’m sure there are a handfull of people in this world that know more about headlights than I do, but I will do my best to prove that I can hang with the best of them.

My purpose for creating this blog is to offer a resource to the public about headlights.