mtrotman
01-31-2006, 05:46 AM
Below you will find a summary of the discussions regarding fog lights. The entire article can be found HERE (http://www.nhtsa.dot.gov/cars/rules/rulings/glare.html).
DEPARTMENT OF TRANSPORTATION
National Highway Traffic Safety Administration
49 CFR Part 571
[Docket No. 01-8885; Notice 01]
RIN 2127-AH81
Glare from Headlamps and other Front Mounted Lamps
Federal Motor Vehicle Safety Standard No. 108;
Lamps, Reflective Devices, and Associated Equipment
2.4 - Glare from Fog Lamps, Driving Lamps, and Auxiliary Low Beam Headlamps
Fog lamps, driving lamps, and auxiliary low beam headlamps are lamps used in addition to the normally required headlamps. These lamps have been identified in state laws for decades as being allowed to be used under certain conditions of visibility. Generally, as defined in SAE standards, fog lamps have a wide even beam, less intense than a low beam, and intended to be mounted low to shine out under blankets of fog hovering near the ground, and in other conditions of reduced visibility such as rain, snow and dust. Properly aimed, fog lamps can be used to reduce the back scatter glare that often results from water droplets, snowflakes and dust particles illuminated by headlamps. The fog lamp with its downward aimed beam can reduce that veiling glare and permit seeing, albeit at much shorter distance, the roadway and important targets. Speeds, of course, have to be reduced under those conditions.
Driving lamps are lamps not intended for general driving, but are intended to supplement the upper beam headlamps. In essence, they are auxiliary upper beam headlamps. As such, they should never be used under conditions that do not permit the use of upper beam headlamps. Their beam intensity and aim are described in SAE standards and often referenced in state motor vehicle law.
The Auxiliary Low Beam Headlamp, is just that, a lamp similar in beam pattern and performance to a lower beam headlamp. It is intended to supplement the lower beam headlamp, more typically for turnpike driving, where the roadway has widely separated opposing lanes.
More and more passenger cars and LTVs are being equipped with auxiliary lamps these days. As an OEM option, the lamps, usually fog lamps, offer different styling cues than the normal model vehicle to help differentiate it in the market. Also, the public may be interested in "better" lighting, because the number of both OEM and aftermarket installations is increasing markedly. Because of fog lamps' limited performance, they by design will not markedly improve seeing under normal conditions.
These auxiliary lamps are now becoming a source of complaint for glare. Often described as another set of headlamps, sometimes mounted lower, the public reports that these lamps seem to be used all the time at night. In fact, research has now documented that the public is right. Sivak et. al. reported that fog lamps were in fact used much more often than was appropriate for the conditions. In fact, most of the auxiliary lamps in the census were on regardless of the weather or visibility conditions, and most vehicles that had them installed had them in use (see Sivak, M.; Flannagan, M. J.; Traube, E. C.; Hashimoto, H.; Kojima, S. 1997, "Fog lamps: Frequency of Installation and Nature of Use," No. UMTRI-96-31, available as Docket NHTSA-1998-8885-1).
This documented misuse of fog lamps in particular helps substantiate the complaints that NHTSA has been receiving. NHTSA has had complaints about fog lamp use for a while, but never so many as recently. As part of another rulemaking (63 FR 68233, December 12, 1998), NHTSA asked whether it should regulate fog lamps in general, because it was petitioned to regulate the geometric visibility of fog lamps as installed on motor vehicles. The response by commenters to this question was unanimous: yes, please regulate them. NHTSA's authority to regulate their safety will have the consequence of having a common national standard for them. Some of the commenters suggested waiting until the SAE and other international organizations achieved a harmonized, but updated version of a fog lamp standard. As a result of that request, NHTSA has been waiting several years for this to occur. However, there appears to be significant disagreement within both the SAE's Lighting Committee and the Groupe de Travail Brusselles, 1958 , (GTB) as to what constitutes the current state of industry performance for fog lamps. For the foreseeable future, NHTSA has no expectation that a harmonized fog lamp performance consensus standard will be forthcoming from SAE or GTB. Because of the significant increase in complaints, NHTSA plans to propose action independently of outdated industry standards for fog, auxiliary and driving lamps to regulate these at the federal level.
DEPARTMENT OF TRANSPORTATION
National Highway Traffic Safety Administration
49 CFR Part 571
[Docket No. 01-8885; Notice 01]
RIN 2127-AH81
Glare from Headlamps and other Front Mounted Lamps
Federal Motor Vehicle Safety Standard No. 108;
Lamps, Reflective Devices, and Associated Equipment
2.4 - Glare from Fog Lamps, Driving Lamps, and Auxiliary Low Beam Headlamps
Fog lamps, driving lamps, and auxiliary low beam headlamps are lamps used in addition to the normally required headlamps. These lamps have been identified in state laws for decades as being allowed to be used under certain conditions of visibility. Generally, as defined in SAE standards, fog lamps have a wide even beam, less intense than a low beam, and intended to be mounted low to shine out under blankets of fog hovering near the ground, and in other conditions of reduced visibility such as rain, snow and dust. Properly aimed, fog lamps can be used to reduce the back scatter glare that often results from water droplets, snowflakes and dust particles illuminated by headlamps. The fog lamp with its downward aimed beam can reduce that veiling glare and permit seeing, albeit at much shorter distance, the roadway and important targets. Speeds, of course, have to be reduced under those conditions.
Driving lamps are lamps not intended for general driving, but are intended to supplement the upper beam headlamps. In essence, they are auxiliary upper beam headlamps. As such, they should never be used under conditions that do not permit the use of upper beam headlamps. Their beam intensity and aim are described in SAE standards and often referenced in state motor vehicle law.
The Auxiliary Low Beam Headlamp, is just that, a lamp similar in beam pattern and performance to a lower beam headlamp. It is intended to supplement the lower beam headlamp, more typically for turnpike driving, where the roadway has widely separated opposing lanes.
More and more passenger cars and LTVs are being equipped with auxiliary lamps these days. As an OEM option, the lamps, usually fog lamps, offer different styling cues than the normal model vehicle to help differentiate it in the market. Also, the public may be interested in "better" lighting, because the number of both OEM and aftermarket installations is increasing markedly. Because of fog lamps' limited performance, they by design will not markedly improve seeing under normal conditions.
These auxiliary lamps are now becoming a source of complaint for glare. Often described as another set of headlamps, sometimes mounted lower, the public reports that these lamps seem to be used all the time at night. In fact, research has now documented that the public is right. Sivak et. al. reported that fog lamps were in fact used much more often than was appropriate for the conditions. In fact, most of the auxiliary lamps in the census were on regardless of the weather or visibility conditions, and most vehicles that had them installed had them in use (see Sivak, M.; Flannagan, M. J.; Traube, E. C.; Hashimoto, H.; Kojima, S. 1997, "Fog lamps: Frequency of Installation and Nature of Use," No. UMTRI-96-31, available as Docket NHTSA-1998-8885-1).
This documented misuse of fog lamps in particular helps substantiate the complaints that NHTSA has been receiving. NHTSA has had complaints about fog lamp use for a while, but never so many as recently. As part of another rulemaking (63 FR 68233, December 12, 1998), NHTSA asked whether it should regulate fog lamps in general, because it was petitioned to regulate the geometric visibility of fog lamps as installed on motor vehicles. The response by commenters to this question was unanimous: yes, please regulate them. NHTSA's authority to regulate their safety will have the consequence of having a common national standard for them. Some of the commenters suggested waiting until the SAE and other international organizations achieved a harmonized, but updated version of a fog lamp standard. As a result of that request, NHTSA has been waiting several years for this to occur. However, there appears to be significant disagreement within both the SAE's Lighting Committee and the Groupe de Travail Brusselles, 1958 , (GTB) as to what constitutes the current state of industry performance for fog lamps. For the foreseeable future, NHTSA has no expectation that a harmonized fog lamp performance consensus standard will be forthcoming from SAE or GTB. Because of the significant increase in complaints, NHTSA plans to propose action independently of outdated industry standards for fog, auxiliary and driving lamps to regulate these at the federal level.