[Federal Register Volume 66, Number 189 (Friday, September 28, 2001)]
[Proposed Rules]
[Pages 49594-49608]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 01-24430]


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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

AGENCY: National Highway Traffic Safety Administration (NHTSA), 
Department of Transportation.

ACTION: Request for comments.

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SUMMARY: The agency is currently examining the issues related to glare 
produced by lamps mounted on the fronts of vehicles. Typically, these 
are lower and upper beam headlamps, fog lamps, driving lamps, auxiliary 
lower beam headlamps and daytime running lamps. All except the latter, 
are used almost exclusively at night. Glare associated with daytime 
running lamps is the subject of an ongoing rulemaking intended to 
reduce their intensity (see 63 FR 42348, Docket NHTSA-98-4124

[[Page 49595]]

Notice 1.) This notice does not address daytime running lamps; it does 
address headlamps and other front-of-vehicle roadway illumination lamps 
that are used primarily at night.
    We have received almost two hundred complaints from consumers on 
this subject in the last two years. The three most common complaints we 
have received recently were on the glare created by the higher-mounted 
headlamps, glare from high intensity discharge headlamps (HIDs), and 
glare from ``extra'' headlamps. While we have received complaints about 
upper beams, too, this paper addresses only those lamps mentioned above 
that drivers use in the presence of other drivers. Regardless, the 
subject of glare, whether from lower beams, upper beams, daytime 
running lamps or any other similar lamp, is important to NHTSA.
    The first of the complaints is about high mounted headlamps found 
on sport utility vehicles (SUVs), pickup trucks, and vans, collectively 
known as LTVs. Mounted high enough to place the more intense part of 
their low beam into passenger car inside and outside mirrors and to 
light up the interiors, high mounted headlamps are viewed by many 
drivers as dangerous and intimidating, in addition to being annoying 
and disabling. The second set is about HID headlamps initially found on 
higher priced passenger cars, and recently on LTVs and moderately 
priced passenger cars. Their robust illumination performance and 
whiter, almost blue, color make them easily identifiable as a new 
source of glare. The third set is about extra headlamps, that are those 
auxiliary lamps fitted to motor vehicles that are typically called fog, 
driving and auxiliary headlamps. Potential misuse by drivers and 
characteristics of these popular original equipment and aftermarket 
lamps may be creating a glare problem. All three of these form a common 
thread throughout the letters written to NHTSA about nighttime glare. 
Many of these letters may be found in Docket Number: NHTSA-1998-4820.
    This document discusses these and other issues, some potential 
solutions and asks some questions that we hope will help us find some 
practical and effective solutions for the American public.

DATES: Comments must be received on or before November 27, 2001.

ADDRESSES: Comments must refer to the docket and notice numbers cited 
at the beginning of this notice and be submitted to: Docket Management, 
Room PL-401, 400 Seventh Street SW, Washington, DC 20590. It is 
requested, but not required, that two copies of the comments be 
provided. The Docket Section is open on weekdays from 10 a.m. to 5 p.m. 
Comments may be submitted electronically by logging onto the Dockets 
Management System website at http://dms.dot.gov. Click on ``Help'' to 
obtain instructions for filing the document electronically.

FOR FURTHER INFORMATION CONTACT: For technical issues, please contact 
Mr. Chris Flanigan, Office of Safety Performance Standards, NHTSA, 400 
Seventh Street, SW, Washington, DC 20590. Mr. Flanigan's telephone 
number is (202) 366-4918 and his facsimile number is (202) 366-4329. 
For legal issues please contact Mr. Taylor Vinson, Office of Chief 
Counsel, at the same address. Mr. Vinson's telephone number is (202) 
366-2992.

SUPPLEMENTARY INFORMATION:

Table of Contents

1  Background
2  Specific Issues
    2.1  Glare from High Mounted Headlamps
    2.2  Glare from High Intensity Discharge Headlamps
    2.3  Glare from HID Look-alike Bulbs and Other Colored Headlamp 
Bulbs
    2.4  Glare from Fog Lamps, Driving Lamps, and Auxiliary Low Beam 
Headlamps
    2.5  Voltage to Headlamp
3  Discussions
    3.1  Discussion of Headlamp Performance in General
    3.2  Headlamp Mounting Height Issues
    3.3  Discussion of HID Issues
    3.4  Discussion of Glare from HID Look-alike Bulbs and Other 
Colored Headlamp Bulbs
    3.5  Discussion of Glare from Fog Lamps, Driving Lamps, and 
Auxiliary Low Beam Headlamps
    3.6  Discussion of Voltage to Headlamp

1  Background

    At the turn of the Twentieth Century, with the automobile industry 
still in its infancy, some vehicles began to be equipped with kerosene 
lamps for use as night time road illumination. Within ten years, 
vehicle manufacturers began to use electric headlamps on vehicles. In 
1914, members of the Society of Automotive Engineers (SAE) who were 
involved in the design and specification of motor vehicle lighting 
began to express their first concerns about the glare produced by these 
headlamps. Since that time, SAE members, who were primarily lighting 
and optical engineers, and human factors scientists have sought various 
ways to reduce glare for other drivers and, at the same time, improve 
the roadway illumination for drivers. Over the years, hundreds of 
variations of headlamps and unique technologies have been implemented 
on motor vehicles. For example, there were many variants of glare 
reducing devices, before lower and upper beams became the norm, that 
were achieved by a mechanical metal shield that was rotated into place 
in front of the bulb within the headlamp, typically by using a driver 
actuated cable. The effect was to reduce the emitted light, either 
direct or reflected, leaving only light directed away from oncoming 
drivers. Another example from about 1929, was General Electric's Tung-
Sol Blue-WiteTM headlamp bulb. It was advertised as 
providing whiter light for safer road illumination and added comfort, 
with courtesy extended to others. The pale blue color of the glass, 
reduced the red content of the light emitted.
    Many formal research reports, technical papers and meeting minutes 
of the World's motor vehicle lighting experts have been generated over 
the last nine decades to discuss and tune the delicate balance between 
glare and vision at night from motor vehicle headlamps. These resulted 
in fairly consistent decisions among the headlamp researchers and 
designers around the world. The resultant beam pattern specifications, 
with some subtle variations to accommodate specific roadway and driving 
conditions in different countries, have been incorporated in the 
lighting regulations of many countries for many decades.
    The headlamps available in the first third of the Twentieth Century 
were not nearly as reliable and as resistant to environmental 
degradation as headlamps today. Consequently, the replacement of 
headlamps parts was a persistent safety maintenance and inspection 
issue that concerned the states. This occurred because of the 
proliferation of hard to find replacement lenses, replacement 
reflectors and replacement bulbs. These were often not available at 
local service stations. Thus, in the U.S., the states agreed circa 1937 
to adopt and standardize sealed beam headlamps technology, establishing 
interchangeability as specified in SAE standards as a top safety 
priority. In 1968, in response to Congressional initiatives, Federal 
Motor Vehicle Safety Standard No. 108, ``Lamps, reflective devices, and 
associated equipment,'' (FMVSS No. 108) set, on a national basis, the 
minimum and maximum luminous intensities for headlamps, headlamp 
mounting heights, and standardization of headlamps. This standard 
essentially adopted the existing performance levels in industry 
consensus standards by the SAE. That

[[Page 49596]]

performance, as evolved since the beginning of motor vehicle lighting, 
is still intended today to ensure that a balance between glare and 
necessary illumination is maintained.
    The balance the agency has maintained between visibility for the 
vehicle operator while minimizing glare for other operators has changed 
very little since its Federal codification. In 1968, however, light 
trucks represented only 10 percent of light vehicle sales and the most 
advanced technology used then for lighting was incandescent filament 
type sealed beam lamps.
    The allowable range of total illumination performance in Federal 
standards is fairly wide. There are points in the beam that require 
minimum levels of intensity, maximum levels and some that have both 
minimums and maximums. Between those points, there are no requirements. 
The NHTSA conclusion has been that the nature of headlamp optics tend 
to make additional test points not necessary.
    Also, the range of headlamp mounting height has been relatively 
consistent for decades. In adopting the industry consensus standard, 
NHTSA, set the initial mounting height requirements to be within the 
range of 24 to 54 inches measured to the center of the headlamp. Today, 
NHTSA's requirements set a mounting height range from 22 to 54 inches. 
The range exists to accommodate the wide variations in vehicle size and 
ground clearance needed for vehicles' intended purpose, while 
addressing the need for safety. Heavy duty trucks and LTVs, which may 
use larger tires, usually have headlamps mounted higher than passenger 
cars. This is because the body is higher, so the lamps are higher, too. 
Typically, glare complaints of years past were about heavy trucks. More 
recently, such complaints are rare to non-existent. We believe that it 
is likely that the public has transferred its glare concerns to 
vehicles that represent a larger portion to the total vehicle 
population. Many of the recent glare complaints are about LTV 
headlamps.
    The nature and response to glare is interesting. Whether from 
headlamps or lamps in your home, there is a distinction between glare 
that is disturbing and glare which is disabling. Essentially, as the 
intensity of a light source increases, the impression of the light seen 
by observers can range from barely noticeable to disturbing, and 
eventually disabling. The particular response of an individual to any 
glare source varies based on its luminance, the intensity of ambient 
lighting, the distance and angle between the light source and the 
observer, the duration of observation, the age of the observer, and 
many other factors. Controlling the intensity of the light source is 
one variable among many dozens that affect the glare for drivers. 
Controlling the location of the light source, relative to the 
observer's line of sight, whether direct view or indirect view (e.g. 
from mirrors) is another way. As an example of controlling the 
intensity, the use of day-night mirrors has been available for decades. 
As an example of changing the position, most formal driver's training 
teaches drivers to avert their eyes away from oncoming vehicles' 
headlamps and look toward the road shoulder on their side. The effect 
of this is to increase the angle between the observers' line of sight 
and the glare source, reducing glare and make it less annoying and/or 
disabling.
    In the past, the agency has taken a number of steps to address 
headlamp glare. In the 1970's, NHTSA began research in response to 
consumer suggestions that vehicles should have a lower intensity third 
beam for driving in well-lit areas. A contractor was asked to determine 
whether such a three-beam head lighting system was feasible. This 
system would give the option of using an urban beam, a suburban beam, 
or an open highway beam. The results of this research, however, were 
discouraging, for the reasons discussed below.
    With three beams, choosing the correct beam quickly would be at 
least as important as choosing between just the lower and upper, today. 
A wrong choice because of indecision or because of a poorly thought-out 
switching scheme would cause risk of a crash from either disabling 
glare or from insufficient illumination. Ideally, approaching drivers 
should deselect the upper beam and choose one of the lesser beams. 
Choosing the suburban beam might still achieve disabling glare, 
especially if the opposing driver had chosen the urban beam intended 
for lower speed, higher density traffic. One of the problems was the 
difficulty of devising a switching scheme that would assure that the 
driver would be able to easily select the desired, and hopefully 
correctly chosen, beam. With a three beam system, the selection of the 
particular beam desired, becomes not one of just selecting ``the 
other,'' but of selecting the better of the two remaining choices, and 
switching to it correctly and quickly. Then, and today, the lower or 
upper beam is selected by a simple alternating switching method. A 
switch or stalk is pushed or pulled once, and the other beam is 
selected. There is little likelihood for error, either in choosing or 
selecting. It is a decision that on occasion, must be done virtually 
instantaneously, and mostly without conscious thought.
    Another step that the agency took was to address the issue of 
headlamp misaim. Studies of headlamp aim have shown that as vehicles 
age, the amount of misaim increases. Misaim will cause glare; it will 
also cause loss of seeing distance. Thus, in March of 1997, the agency 
implemented a final rule based on a negotiated rulemaking intended to 
reduce the number of vehicles with misaimed headlamps. The rule 
reflects the consensus of the negotiated rulemaking concerning the 
improvement of headlamp aimability performance and visual/optical 
headlamp aiming. This committee was composed of representatives of 
federal and state governments, world-wide motor vehicle industry, 
industry consensus standards bodies and consumer interest groups.
    The new rule established improved headlamp aiming features that 
will provide more reliable and accurate aiming, and help vehicle 
operators to more easily determine the need for correcting aim. As the 
number of vehicles on the road with these features increases, the 
number of vehicles with misaimed headlamps should decrease. This should 
help to moderate some of the aim-related glare problems.
    While this action results from NHTSA's authority to regulate new 
motor vehicles sold to the public, NHTSA does not regulate motor 
vehicles in use. The states have that responsibility. Thus, it is the 
states that have the authority to regulate the safe condition and 
operation of motor vehicles in use. Headlamp aim and condition 
inspection is an area that is addressed by many states. However, many 
states do not have periodic motor vehicle inspection, and even those 
that do, do not always inspect headlamps.
    Complaints about headlamp glare also accompanied the introduction 
of halogen technology in headlamps that began in 1979. The public wrote 
about the blinding white lights in letters to the press and to NHTSA. 
As introduced, the halogen lamps, generally, were not intended to be 
more intense than non-halogen headlamps; their only distinguishing 
characteristic was that they were whiter in color than other headlamps 
in use. This occurred because the vehicle manufacturers were interested 
in using less energy, while achieving acceptable performance. The 
halogen lamps used about two-thirds of the energy of that of a non-
halogen headlamp. Gradually, vehicle manufacturers chose to provide 
more performance oriented halogen

[[Page 49597]]

headlamps. Many halogen headlamps were made with better than average 
performance within the bounds of the federal safety standards on 
headlighting intensity. The complaints about halogen headlamps ceased 
fairly quickly, however. This may have been because of their widespread 
use and subsequent lack of distinguishing characteristics. By about 
1985, the majority of new vehicles were halogen equipped.
    Now, with the introduction of another new technology for headlamp 
light sources, HID and ``look-alike'' halogen bulbs, combined with the 
increased popularity of LTVs, and the upswing in auxiliary lamp use, 
citizens have begun to complain about headlamp glare again. The agency 
has received hundreds of letters regarding glare from the new ``blue'' 
headlamps on luxury cars, and about the glare from the ever increasing 
number of LTVs. Also, over the last three years, the number of glare 
complaints about fog and other auxiliary front-mounted lamps has 
increased substantially. This may be because of the significantly 
increased OEM installation of optional fog lamps and the similar 
increased aftermarket installations by the public on vehicles in use. 
This is accompanied by frequent misuse of these lamps: using fog lamps 
during conditions other than permitted by most states' laws. They are 
reported to be most often used at night in clear weather, and not under 
conditions of reduced visibility.
    One critical issue regarding glare is whether it increases the risk 
of being in a crash. Given this renewed response to glare, complaints 
do not mention crash involvement, yet concern about that issue is 
expressed. While it is easy to say that there are few, if any, crashes 
that are documented to have been directly caused by nighttime glare 
from other vehicles, it may not be totally representative of the 
relationship between glare and crashes.
    The drivers' dependence upon artificial lighting and the lesser 
field of view at night are factors that contribute to this greater 
safety risk. In these circumstances, glare, whether at the levels that 
are annoying or disabling, increases the stress for drivers. Increasing 
stress for drivers in a more dangerous nighttime environment has 
adverse safety consequences, even if those consequences can not be 
precisely quantified. Many remedies for glare work by reducing the 
driver's vision of the driving environment; for example, switching 
mirrors to the nighttime driving position or averting one's eyes to the 
right shoulder instead of the middle of the road. It is reasonable to 
assume that reducing vision will lessen the amount of warning a driver 
has of particular risks, and that, in at least some cases, less 
reaction time will result in more crashes. Accordingly, NHTSA believes 
increased glare is something the American people are experiencing, and 
that this glare raises important safety concerns that need to be 
addressed thoughtfully and effectively.

2  Specific Issues

2.1  Glare from High Mounted Headlamps

    Because LTVs, in general, are taller than passenger cars, their 
headlamps are generally mounted higher than those of passenger cars. 
This often occurs for styling or functionality purposes, the latter 
related to load carrying capacity and potential off-road use. Whenever 
a headlamp is higher than an observer's eyes, or higher than the height 
of a mirror, the more intense portions of the lower beam, those 
portions aimed straight to downward, can cause much greater glare than 
the portions of the beam aimed upward. This height differential creates 
a problem for operators of lower vehicles, when the more intense areas 
of the taller vehicle's headlamps, shine directly into the eyes of 
oncoming drivers or into the mirrors of preceding vehicles. The 
oncoming drivers experience transient glare because of the rate of 
closure speed, the quickly widening angle from the observer to the 
glare source, and the transient nature of hills and curves. Preceding 
drivers, however, can experience long term reflected glare and high 
interior brightness adaptation. They are more likely to have greater 
discomfort and disability, and thus, higher risk of a crash.
    Consequently, the agency is interested in examining the issue of 
headlamp mounting height on LTVs that have a gross vehicle weight 
rating of 10,000 pounds or less, for their ability to produce glare, 
and for what potential solutions can be implemented to reduce the glare 
and its consequences.
    In model year 2000, LTVs achieved about 50 percent of new vehicle 
sales, adding about eight million of them every year to the 170 million 
vehicle national fleet. With this steady increase, the average headlamp 
mounting height is increasing. This results in more and more glare 
events being experienced by drivers.
    The most obvious way to address the issue of high-mounted headlamps 
is to reduce the permissible mounting height. As noted previously, the 
current maximum mounting height for headlamps is 54 inches. This limit 
was adopted in 1968 from existing state laws and consensus standards. 
However, this limit is so high as to leave the maximum mounting height 
essentially unregulated for most light vehicles. While that choice may 
have been acceptable when nearly all light vehicles were cars (so the 
range of actual mounting heights was within a relatively narrow 
margin), it may not be as appropriate as the light vehicle fleet 
becomes more evenly divided between cars and LTVs.
    An independent organization, the SAE, is also looking at glare from 
higher-mounted headlamps. The SAE's Lighting Committee is the source 
for many automotive lighting standards in the United States (including 
many already incorporated in the Federal lighting standard) whether 
they are used voluntarily by manufacturers or referenced in state or 
Federal laws. The SAE Lighting Committee's Headlamp Mounting Height 
Task Force examined the issue of truck headlamp mounting height and its 
relationship to glare in 1996 and published a report on that effort 
(SAE J2328 OCT96). This report concluded that headlamp mounting height 
for trucks should be lowered, but the task force could not achieve a 
consensus for a new lower maximum mounting height. The task force 
discussed 900 mm and 1000 mm maximum mounting heights (as compared to 
the current 1370 mm maximum), but got no definitive majority for either 
alternate maximum limit. A minority opinion was that factors other than 
headlamp mounting height should also be studied, including beam 
distribution, headlamp output, rearview mirror reflectivity, and 
different glare limits. The 1996 report did forewarn that as headlamps 
incorporating new technology are implemented to improve seeing, there 
is the distinct possibility of increasing glare to others if headlamp 
mounting height is not lowered on trucks. The report concluded that the 
transportation industry and standards associations should consider 
significantly reducing the mounting height of headlamps on light trucks 
and MPVs.
    The Headlamp Mounting Height Task Force then reconvened to further 
examine the issue of mounting height of light truck headlamps and 
glare. At the Fall 1999 SAE Lighting Committee meetings in Cleveland, 
Ohio, the Chairman of the Headlamp Mounting Height Task Force commented 
on data that showed a substantial increase in side mirror luminance, or 
glare, as the mounting height of the following vehicle's headlamps 
increased. The data show that historically the driving public has been 
exposed to between three and six lux in the side mirror with sealed

[[Page 49598]]

beam headlamps and early replaceable-bulb types using transverse bulb 
filaments. With the advent of axially-oriented bulbs in newer 
replaceable-bulb headlamps, the side mirrors are now illuminated to 
more than 50 lux when the headlamps are 12 inches higher than the 
mirror, a not uncommon difference between car mirrors and LTV 
headlamps. During this same meeting, other measures to limit glare from 
high-mounted headlamps were also discussed, such as using special 
automatic-dimming mirrors and altering headlamp beam patterns. The data 
discussed are not available; however, that task force is preparing a 
document that is intended to be published by the SAE sometime later 
this year.
    Lowering the headlamp height is likely to be a very effective 
solution to the glare problem associated with higher mounted headlamps. 
One reason that might be brought forward to NHTSA by commenters for not 
pursuing this direct approach is that it might necessitate a redesign 
of the front ends of some LTVs which potentially imposes substantial 
costs if that redesign occurs sooner than a vehicle manufacturer had 
planned. However, such costs would be minimized if lower headlamp 
heights were one of the parameters that had to be accomplished during a 
scheduled redesign or refreshing of the front end of the vehicle. 
Another concern likely to be expressed by commenters is that the 
utility of the vehicles could be reduced if the redesigns needed to 
accommodate lowered headlamps resulted in significantly lessened load 
capacity or off-road capabilities. Significantly reducing the off-road 
capabilities of LTVs could make them less desirable to potential 
purchasers. NHTSA notes, however, that some Daimler-Chrysler LTVs, 
specifically the Ram pickup and the Durango sport utility vehicle, have 
headlamps mounted lower than some other manufacturers' LTVs and that 
this has been accomplished without reducing the off-road capabilities 
of those vehicles, to the best of NHTSA's knowledge. NHTSA also notes 
the new Model 2002 Chevrolet Avalanche, a five door/short bed sport 
utility vehicle has headlamps mounted below the turn signal lamps. The 
height of these lower beam lamps is about 890 mm (35 inches). This new 
vehicle does not appear to be hampered in capability or marketing 
value. NHTSA prefers a policy of making the vehicle type (LTVs) that 
caused the problem (glare for other drivers) achieve the solution, as 
long as it is done in a manner that considers the magnitude of the 
problem and the cost of the fix.
    There are other approaches to addressing the problem of glare from 
high-mounted light truck headlamps, although none so intuitively 
appealing as the above. One approach is to make a special beam pattern 
for headlamps to be mounted above a certain height. This is an 
alternative that the SAE task force continues to consider. It is 
certainly possible to develop a beam pattern that would reduce the 
glare from current levels. It would appear to be a challenge, however, 
to develop a pattern that reduced glare at higher mounting heights 
while still providing acceptable light for illuminating the roadway. 
Another approach would be to adjust the aim of light truck headlamps 
down, thereby decreasing the distance in front of such a headlamp where 
it could cause glare for other drivers. Again, however, NHTSA would 
need to be assured that this aim adjustment would still result in 
acceptable roadway illumination for the LTV driver. A significant 
advantage of these approaches is that the costs for the new light with 
the altered beam pattern or the altered aim would be borne by the 
purchasers of the vehicles with the higher-mounted headlamps that were 
causing the glare issues for other vehicles.
    Other approaches involve modifying cars so their drivers experience 
less glare from the higher-mounted headlamps on LTVs. As a policy 
matter, these approaches are less appealing since they oblige 
purchasers of vehicles that receive the LTVs' glare to bear the entire 
burden of addressing that glare problem. One approach in this category 
is to require enhanced mirrors on cars. Automatic electro-mechanical 
dimming inside mirrors have been available for decades as standard 
equipment on luxury models and as an option in many vehicles. More 
recently, there have been electronically dimming mirrors, typically 
called photochromic and liquid crystal automatic dimming mirrors. The 
advantage of these mirrors is that they reduce the intensities of 
incoming light at least as well as manual or electro-mechanical auto-
dimming interior mirrors, but they also reduce glare reflected from the 
outside mirrors as well. The primary disadvantages are that these 
mirrors can add $100 or more to the cost of a new vehicle and they can 
lessen only the glare from following vehicles.
    Another approach to addressing glare from following vehicles' high-
mounted headlamps is to reduce the amount of light reflected off the 
interior surfaces of the car, particularly the instrument panel and the 
inside surface of the windshield. These changes would have the 
concurrent advantage of enhancing visibility during the day, when 
veiling glare may occur as light reflects from the inside of the 
windshield onto the instrument panel. Again, these costs would be borne 
by the glare burdened driver, and help only with glare from following 
vehicles.
    A third indirect approach, would be to reduce light transmitted 
through side and rear windows on cars. Cars are currently required to 
have at least 70 percent light transmittance through all windows. 
Reducing the light transmission through the glazing would reduce glare, 
but vehicles that have reduced light transmission also have outside 
mirrors, usually larger ones, that will reflect glare quite handily. 
However, reducing visibility through side and rear windows would also 
reduce the ability of drivers to see through those windows when it is 
important to safety to see clearly and well. Tinted glazing can also 
reduce the effectiveness of mandated safety equipment like inside rear 
view mirrors and center high-mounted stop lamps. NHTSA would prefer to 
address glare without trading off safety performance in other areas.

2.2  Glare From High Intensity Discharge Headlamps

    In the case of HIDs, we have received numerous complaints stating 
that these newer lamps produce excessive glare. Even though they are 
required to comply with all federal lighting requirements, HIDs are 
still being singled out as being troublesome glare producers for other 
drivers. The reason expressed by drivers is that the HID headlamps are 
brighter. This may be due to the spectral content of the produced 
light, the generally wider and more robust beam pattern, and/or their 
conspicuous color relative to other headlamps, or misaim.
    In an effort to create a headlamp which provides better 
illumination, longer life, and a unique styling appearance, vehicle 
lighting manufacturers developed HIDs. They have been typically offered 
on higher end vehicles and can cost as much as $400 to $800 for the 
option. HIDs are unlike conventional halogen headlamps in that they 
operate more like street lamps. Instead of heating a tungsten filament, 
an electrical arc is created between two electrodes. This excites a gas 
inside the headlamp (usually xenon) which in turn vaporizes metallic 
salts. These vaporized metallic salts sustain the arc and emit the 
light used for the headlamp's beam. These lamps provide more light than 
that produced by halogen lamps and only use two-thirds

[[Page 49599]]

the power. As a result, they are more efficient, and because there is 
no filament to burn out, these bulbs are claimed to last for as much as 
100,000 miles of driving time.
    Although the agency has seen advertising and received many 
complaints claiming that the light produced by HIDs is twice or three 
times as bright as that which is produced by halogen lamps, laboratory 
measurement, made by various parties, do not support these claims. HID 
light sources (bulbs) typically have about two to three times the 
available light flux (volume) of halogen light sources, but because of 
such an abundance of light, the HID optical design does not necessarily 
need to be as efficient at collecting and distributing light as a 
halogen system. The HID beam pattern is certainly more robust, 
providing more even and wider illumination and the potential for better 
visibility and comfort. This performance results in more light on the 
road surface and more of the roadway being illuminated. However, this 
additional light is not supposed to be projected upward from the lamp 
toward other drivers' eyes. During inclement weather, when the road 
surface is wet, the additional volume of light can result in higher 
levels of light reflected off the road surface into other drivers' 
eyes. However, those who have complained about HID glare have not 
specifically reported inclement weather as the only time when there is 
a problem with HID glare.
    Another factor that may be involved is the phenomenon that may have 
occurred with the introduction of halogen lamps in the early 1980's. 
Drivers are attracted to headlamps that are different colors than would 
normally be seen. As such, the drivers may look directly at oncoming 
headlamps during driving to see the unfamiliar item. This is something 
that they do not normally do. Initial halogen headlamp introduction 
elicited some glare complaints, even though the first halogens used 
were actually very similar in performance to the standard non-halogens 
headlamps. The only marked difference was the color of the halogen 
headlamps. If this is the case now, one would expect glare complaints 
about HIDs to stop when drivers become familiar with the HID color. 
However, NHTSA is aware of no studies or evidence to suggest that this 
theory is correct.
    Another factor that may lead to the perception that HIDs are 
significantly brighter than halogen lamps is that human eyes may be 
more sensitive to bluish-white light of HIDs than to yellowish-white 
light of halogens. When observing some HIDs, it may seem that they are 
not emitting white light, as required by Standard No. 108. However, 
when observing the beam pattern projected on a white screen, HID 
headlamps that comply with our lighting standard will appear to be 
white with color separations occurring only at the extreme edges of the 
pattern. Non-halogen, halogen, and HID light sources appear to be 
different colors to observers. Non-halogen lamps appear to be yellow 
when compared to halogen lamps, and halogen lamps appear to be yellow 
when compared to HIDs.
    In a recent study by the University of Michigan Transportation 
Research Institute (Flannagan, M. J.; 1999, ``Subjective and Objective 
Aspects of Headlamp Glare: Effects of Size and Spectral Power 
Distribution,'' Report No. UMTRI-99-36, available in Docket Number: 
NHTSA-2001-8885-3) the differences reported between halogen versus HID 
lamps caused a small but statistically significant difference in 
discomfort glare noted by observers. However, it had no effect on 
disability glare. It is not known yet whether it is the difference in 
spectral power density of these headlamps, but this difference in the 
human eye's glare response to these different lamp designs is shown in 
that study.
    HIDs are not just more white (having less yellow content and more 
blue content in the emitted spectrum), but the light is generated in a 
different manner. HIDs achieve light by having vaporized metallic salts 
participate in the electrical current flow through an arc in the bulb 
capsule. This is contrasted to a heated metal filament which gives a 
relatively even level of light at all colors in the spectrum, and thus 
achieves smoother white light. The HIDs blend of metallic salts is 
designed such that the different salts, emitting different colors of 
light with different energy levels, will complement each other when 
fully heated and electricity is passed through them, because each salt 
contributes various frequencies of light and at different levels of 
energy. The result is white light, but with a few relatively high 
energy spikes of light at very narrow bandwidths. These spikes are 
obvious in a mapping of the spectral power density of the light 
emitted. (See Docket Number: NHTSA-2001-8885-4, USA Today, June 7, 
2001, ``Bright Lights, Big Controversy'' by James R. Healey, page 1, 
the side bar ``harsh blue light contributes to glare''). This 
comparison shows that the light spectrum of HIDs is not as smooth as 
the light from a heated filament in a halogen lamp. It is possible that 
our eyes are not necessarily reacting to the whiter light, but to the 
high energy spikes that rise above a background energy achieving the 
white light. If this is a cause for the UMTRI findings, it may be that 
a redesign of the HID system is necessary. However, this is just a 
theory, with no supporting data. NHTSA is initiating research to study 
all potential factors that may be causing HIDs to be an annoying 
lighting source.

2.3  Glare From HID Look-Alike Bulbs and Other Colored Headlamp Bulbs

    The advent of HIDs on more expensive vehicles has spawned attempts 
at achieving halogen-based look-a-likes. These are achieved by using 
coated, tinted, filtered or otherwise altered glass capsules for the 
halogen headlamp bulbs that can be used in place of the OEM bulbs. 
Alternatively, aftermarket headlamp housings with similar coating, 
tinting and filtering are being sold as replacements for OEM headlamps. 
The goal of many of these bulbs is to emit light that is different than 
an OEM halogen headlamp bulb, while attempting to maintain a headlamp's 
legally complying performance. The whiter light is offered as being 
closer in color to natural daylight, thus the claim is that drivers see 
better with the same amount of emitted light. This is not unique in 
motor vehicle lighting history; in fact, it is the same claim and 
intent as accompanied the 1929 Tung-Sol Blue-Wite TM 
headlamp bulb. The yellow variants of colored bulbs are intended to be 
more useful in wet weather where the color, still measured to be white, 
is more yellow than OEM halogen bulbs. The intent is to offer a color 
of light less likely to be reflected back from precipitation and fog. 
At the other extreme of colored aftermarket bulbs, are those that are 
very blue or multicolored. The multicolored bulbs are the result of 
many different colors being emitted by the bulb in various directions, 
instead of white light being emitted in all directions as occurs in 
normal halogen bulbs.
    Generically categorized as ``blue'' bulbs, all of these aftermarket 
bulbs have become popular among some drivers, either because the bulbs 
produce the look of a more expensive vehicle at a fraction of the cost, 
or claims of improved visibility. Many of the bulbs are from well known 
bulb manufacturers, others are from less familiar companies and 
importers. Depending on the make and model of bulb desired, some are 
sold by auto parts stores and mass merchandisers, others are sold by 
specialty auto accessory stores and through the

[[Page 49600]]

Internet. While there are no reasons to believe that all such bulbs 
cause headlamps to perform badly, many such bulbs do just that, as 
explained below.
    Designing original equipment headlamp bulbs is a precise science, 
fraught with many design compromises in order to achieve the desired 
balance of energy usage, service life, emitted light and robust optical 
images of the filament. In general, headlamp bulb designs take years of 
thoughtful work in consultation with the designers of headlamp optics. 
The OEM bulb design is standardized and codified by industry consensus 
in SAE and International Electrotechnical Committee (IEC) standards so 
that all bulb manufacturers can build and sell bulbs with the 
expectation that they will perform in a safe and satisfactory manner in 
all headlamps in service. This standardization is incorporated into 
Federal Motor Vehicle Safety Standard No. 108, Lamps, reflective 
devices and associated equipment (FMVSS 108) by referencing information 
about each bulb. This information is in Docket Number: NHTSA-98-3397.
    When changing the basic design of a headlamp bulb the way that 
placing a coating, filter or tinting can, the results can range from 
just color changes to reducing the emitted volume of light from a 
headlamp by almost half. For example, certain kinds of filters and 
coatings, while having the effect of reducing yellow light emission, 
are sometimes also very reflective. The result is that, instead of most 
of the light coming from the filament directly through the glass 
capsule and being used by the headlamp's optical design to have a 
focused beam down the road, the light bounces once or twice off the 
inner wall of the bulb. This causes strong images of the filament to be 
emitted from the capsule in directions and intensities never possible 
in the standardized OEM design. Because headlamps are designed to use 
standardized bulbs, the lighting performance of the headlamp could be 
markedly different, both impairing seeing down the road and causing 
others to have undue glare, when a modified, non-standardized bulb is 
substituted. Such poorly designed bulbs may also be a reason for the 
public's glare complaints.
    In contrast, if the bulb designer uses a more benign filter 
element, the inner bulb reflectivity may be substantially reduced or 
virtually eliminated. For a bulb that is intended to be whiter, less 
yellow light may be emitted, giving the light a whiter, even bluish 
light, but still white light as defined in various industrial and legal 
standards. To assure that this bulb emits the equivalent and correct 
volume of light compared to an OEM version, the filament design must be 
subtly changed, but not so much so that wattage increases above the 
acceptable limits required of a standard bulb. These careful changes 
may continue to make the bulb interchangeable with an OEM design 
without noticeable consequence other than whiter light.
    Besides replacing the OEM bulbs with bulbs with the characteristics 
described above, it is possible to purchase whole headlamps and 
replacement lenses for those that are replaceable, that are tinted. 
Under our standards, these must comply, with our lighting standard but 
again, the blue, or other color, tinting may have similar adverse 
disturbing and disabling glare effects.
    Another disturbing trend in this look-a-like phenomenon is the 
substitution of OEM filament headlamp bulbs with aftermarket HID 
conversion bulbs. The desire is to achieve the look and achieve the 
more robust performance of HIDs. While not designed to be 
interchangeable, some aftermarket companies are substantially altering 
the HID bulb bases or providing adapters so that the HID bulbs can be 
inserted in headlamps designed for filament bulbs. The consequence of 
making these substitutions is to adversely affect safety. Filament 
headlamps are optically designed for the volume of light and filament 
placement and other critical dimensions and performance that OEM 
filament bulbs have. The HID conversions result in two to three times 
the volume of light and potentially imprecise arc placement. Such 
conversions often result in beam patterns that behave nothing like the 
original filament beam pattern, cannot be reliably aimed, and have many 
times the permitted glare intensity. In informal conversations with 
persons who have tested such conversions, the light intensity on one at 
a point aimed toward oncoming drivers was 22 times the allowable 
intensity limit. Another lamp was more than 7 times too intense. With 
poor HID bulb and arc placement, the glare intensity could be 
significantly worse. Thus, the use of these conversions could be yet 
another source of the glare problems about which many drivers have 
complained.
    Regarding bluer light achieved by these filament bulbs, recent 
research (Sullivan, J.M. and Flannagan, M.J.: ``Visual Effects of Blue-
Tinted Tungsten-Halogen Headlamp Bulbs'', Report No. UMTRI-2001-9, 
available in Docket: NHTSA-2001-8885-2) shows consistency with prior 
research, that discomfort glare ratings increase as the chromaticity 
moves toward the blue color range of the visible light spectrum. The 
authors also state that there is no evidence to show that target 
detection is enhanced with such blue colored headlamps, either in 
direct viewing or peripheral viewing of illuminated targets. This, 
essentially, shows that there likely is an inherent disbenefit from the 
use of such blue bulbs and headlamps that are intended to change the 
color of light emitted from headlamps. While one might assume that this 
also applies to the bluer HID powered OEM headlamps, the authors did 
not study this, nor speculate about it.

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

[[Page 49601]]

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. NHTSAs 
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\1\, 
(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.
---------------------------------------------------------------------------

    \1\ The GTB is the organization of motor vehicle and lighting 
industry experts that advises the United Nation's rulemaking 
organization that is responsible for Economic Commission for Europe 
vehicle regulations.
---------------------------------------------------------------------------

2.5  Voltage to Headlamp

    The voltage supplied to headlamps is one of many factors that 
establish the performance achieved. Safety Standard No. 108 specifies 
that headlamps be tested in a laboratory for the purposes of compliance 
at a test voltage of 12.8 volts D.C. The designers of headlamps and 
their filament type bulbs rely on this standardized voltage to assure 
that when anyone tests the headlamp at the standardized voltage, the 
lamp will perform as prescribed in the law. The lamp designers, in 
setting out to design the headlamp, use the standardized specifications 
set forth for the light source (bulb), determined at 12.8 volts and use 
them as part of the calculations for the prescriptions of the lamp's 
optical elements. The finished product is a lamp design that will be 
reliable, be capable of mass production, and meet the prescribed 
illumination performance set out in the Standard.
    Unfortunately for drivers, the lamp performance experienced in the 
real world on their vehicles is not always the performance measured in 
the laboratory. The reason for this is that motor vehicles need to 
store vast amounts of electrical energy in its battery, and must have a 
electrical charging system to supply the energy that is stored. That 
charging system must provide varying voltages to charge the battery. 
Batteries expend some of that energy when used to start the vehicle's 
engine. To fully charge the battery, a voltage higher than that of the 
battery is necessary to return energy to the battery for storage and 
future availability. Depending on the state of charge of the battery, 
the ambient temperature, the quickness of restoration designed into the 
charging system, and other factors, the voltage of the vehicle's 
electrical system may be as high as 14 or 15 volts. On the other hand, 
it may be below 12.8 volts, if the ambient temperature is very low.
    The effect on filament headlamps, taking into consideration the 
electrical resistance of the wiring to them, the headlamp switch, 
fuses, distribution panels, relays, and other devices often found in 
the headlamp circuit, is to reduce the voltage slightly when compared 
to the voltage at the battery. When the standardization of test voltage 
was conceived, it was intended to accommodate this vehicle electrical 
system variability by testing at the typical operating voltage of the 
headlamp, such that the lamp in a motor vehicle could be expected to 
operate most of the time with the same intensity as measured in the 
laboratory, and as specified for it.
    Over the years, the design of motor vehicle electrical systems has 
evolved such that the amount of electrical energy necessary to operate 
the myriad of electrically powered devices, has more than quadrupled in 
many cases, from what was needed twenty or thirty or more years ago. 
With the advent of electrically powered steering and brakes, and 
complex environmental systems, the electrical energy need will continue 
to increase. To supply all this energy and to still charge the battery 
in a quick manner, the average voltage on vehicles has increased over 
the years. The consequence to many vehicles as stated above, is that 
for headlamps, the operating voltage is more likely to be somewhat 
above the specified test voltage.
    In NHTSA's experience in measuring the voltage supplied to daytime 
running lamps, that voltage can be at least 14 volts. Others who have 
measured the voltage of headlamps have documented such high voltages, 
too. Even vehicle manufacturers have documented voltages higher than 
12.8 volts. The effect on increased intensity as a result of varying 
voltages to filament type headlamps can be seen in the table below. It 
provides a multiplier for finding the new intensity when going from one 
voltage to a higher or lower one.

----------------------------------------------------------------------------------------------------------------
                                                                 Factor to use to get candela at:
             Candela specified at:              ----------------------------------------------------------------
                                                    12.0 V       12.8 V       13.2 V       13.5 V       14.0 V
----------------------------------------------------------------------------------------------------------------
12.0 V.........................................          1.0         1.25         1.37         1.50         1.68
12.8 V.........................................         0.80          1.0          1.1          1.2         1.35
13.2 V.........................................         0.73         0.90          1.0         1.07         1.23

[[Page 49602]]

 
13.5 V.........................................         0.67         0.83         0.93          1.0         1.14
14.0 V.........................................         0.60         0.74         0.81         0.88          1.0
----------------------------------------------------------------------------------------------------------------

    In the case of U.S. headlamps, 12.8 is the specified test voltage 
in FMVSS No. 108. However, moving to the right in the row, one can see 
that if the vehicle voltage at the headlamp was only 12 volts, the 
headlamp's intensity would be only 80 percent of the specified 
intensity. Conversely, if the voltage measured on the vehicle were 14 
volts, the headlamp would be operating at 135 percent of its specified 
intensity. The consequence for a driver in these two cases would be 
respectively, less light on the road and less glare to others, and more 
light on the road and more glare to drivers. Both situations are 
possible, depending on many factors as stated earlier. The possibility 
of newer vehicles having headlamps operating at higher than specified 
intensities is very real. For your vehicle, you would probably be more 
comfortable with the higher voltage and higher intensity. Drivers who 
oppose you probably would not appreciate that more robust performance.

3  Discussions

3.1  Discussion of Headlamp Performance in General

    As was discussed above, the specification of a lower beam headlamp 
pattern slowly evolved over the last one hundred years. In the U.S., 
most of that work was done by motor vehicle lighting engineers and 
other automotive engineers and human factors scientists through the 
auspices of SAE. Today, that beam pattern as codified in FMVSS No. 108 
is certainly more robust than it was in 1914, 1937, 1968, or 1985. The 
latest performance change in 1997 made the beam wider to lessen its 
sensitivity to horizontal misaim and to add a horizontally oriented 
cutoff delineating a sharp gradient between the higher intensity 
roadway light below and lesser intensity glare/sign light above. This 
cutoff was the cue for determining correct aim of the beam. Still, the 
fundamental aspects of specifying the beam's performance remained the 
same as it has for over the last hundred years: Individual test points 
in various places on an angular coordinate system with the axis 
originating at the headlamp lens center. The test point performance 
specified is applied to each headlamp, and the consequence is that each 
individual headlamp has the same general beam pattern. Yet, because 
lamps are made by many different companies, with differing customer 
needs, headlamps for different models of vehicles can have visually 
different beam patterns and performance, and still comply with the 
specifications set forth in FMVSS No. 108. Regardless of headlamp 
mounting height or separation distance, the Federal specification for 
the beam pattern is the same (and at the state level, the aim is almost 
always the same.) Thus, the result is what we now have in our vehicles-
varying performance between vehicle makes and models, and even between 
makes of headlamps. The inherent philosophy that guided this evolution 
was absolute interchangeability and ease and quickness of replacement 
(to limit the time and miles driven before replacement of the failed 
lamp occurs). That was the basis for the 1937 decision to mandate 
sealed beam headlamps. All were the same so there would be only one 
model to find at the local service station. Considering how often 
headlamp bulbs, lenses and reflectors failed prior to 1937, this was a 
paramount safety concern. Until 1983, this was still the basic 
approach, although a few alternative sizes and shapes were introduced. 
Then the standardized replaceable bulb headlamp was introduced, 
allowing virtually any size or shape of headlamp, but using the 
universal, standardized, replaceable light source. It was this 
standardized, colorless bulb that was to be readily available at many 
stores, many of which were no longer service stations. The additional 
performance required of these headlamps was intended to assure that 
they had long term environmental resistance performance similar to what 
sealed beams had.
    This move toward headlamp housings made specifically for an 
individual make, model and year of vehicle, together with substantially 
longer bulb life, led NHTSA to consider the potential for having a 
vehicle-based roadway illumination performance requirement. As 
envisioned, the vehicle as assembled, regardless of the type of 
headlamps, the type of vehicle, the mounting height or separation 
distance, would be required to illuminate the roadway in a certain 
manner, taking into account all the various important and often 
conflicting aspects of illumination versus glare. Such an approach 
would ensure that a vehicle's lighting performance would be evaluated 
just as it would be on the road when used by the public, and remove 
NHTSA from the business of specifying details of bulb and lamp design. 
With this approach, the challenge for vehicle manufacturers was that 
the performance had to be designed into the vehicle, rather than being 
added on at the end. Consideration of the vehicle's performance is 
required by most of NHTSA's safety standards, but not for compliance 
with many aspects of FMVSS 108. To specify the roadway illumination and 
glare performance of the whole vehicle would add design complexity and 
make compliance test procedures more expensive, and time-consuming. 
Both vehicle and lamp manufacturers have commented that a move toward a 
more systems-based approach toward vehicle lighting is not desirable 
because of these issues.
    Given the dilemma raised above, NHTSA has not pursued this approach 
since investigating in the late 1980s. We would like your comment on 
the following questions:
    Question 1: Given the vast amount of new technology in headlamp 
hardware and design, and in the design of light sources, is the long-
standing method of specifying a single headlamp's performance by test 
points irrespective of its particular vehicle application, still an 
effective way to consider the problem of glare? Please explain.
    Question 2: Is there any feasible alternative, such as having many 
more test points in and near the glare areas in the beam? Would 
applying intensity zones for glare be appropriate instead of points? 
Would a whole vehicle roadway illumination specification solve the 
problem, limiting glare regardless of lamp mounting height? Please 
discuss these and fully explain your reasoning for your choice or 
suggestions.
    One consideration in deciding whether to proceed with regulations 
in this area is assessing how effectively an industry is addressing a 
problem. With respect to lighting generally, the vehicle and headlamp 
manufacturers' customers are most likely to complain if the lamps are 
not robust enough to allow good nighttime driving visibility. The glare 
from the lamps would not disturb the

[[Page 49603]]

customer of this vehicle or headlamp unless the lamps were so glaring 
that every passing vehicle flashed its lights. In these circumstances, 
the charge to designers could be to get as much light as possible from 
the headlamps and consider glare only to the extent necessary to comply 
with legal requirements. Alternatively, designers could be charged with 
producing lights that deliver good lighting performance but also 
consider how this headlamp design will affect others on the road.
    Question 3: To what extent do lamp or vehicle manufacturers 
consider potential glare from headlamps beyond the glare limits set in 
the Federal lighting standard? What assessment is made of potential 
glare from lamps at points in the beam pattern that are unregulated? 
Are there any lamp or vehicle manufacturer corporate design guidelines 
that lamp or vehicle manufacturers use at unregulated points in the 
beam pattern? If so, please indicate what those guidelines are and 
explain why the manufacturer believes they are appropriate. Please 
provide examples of specific headlamp designs and identify changes that 
were made to the beam pattern specifically to reduce glare for other 
drivers, even though the beam pattern met the existing Federal 
standard.
    Question 4: To what extent do vehicle manufacturers consider 
potential glare from headlamps as installed on their vehicles, even 
though this is not currently required by the Federal lighting standard? 
Please provide details on the assessment procedures that are used. Do 
vehicle manufacturers routinely evaluate prototype vehicles driven at 
night as occupants of other vehicles to evaluate the potential glare 
from headlamps? Are there other assessment methods used to assess the 
glare from the headlamps actually installed on the vehicle before 
vehicle manufacturers commit to a particular headlamp design? Please 
provide examples of specific recent or new vehicles and identify 
changes that were made to the headlamp beam pattern as installed on the 
vehicle, even though such changes were not required by the existing 
Federal standard.
    Question 5: To what extent do lamp and vehicle manufacturers 
consider the reports and work by the Society of Automotive Engineers 
and other non-governmental bodies on the subject of glare in designing 
the performance of lamps on their vehicles? If so, please provide a 
list of the reports, papers and data that you use. Please provide 
specific examples of internal glare limits that have been adopted as a 
result these references.
    Another approach to reduce glare that was mentioned earlier is 
correct aim. While NHTSA has made changes to improve the ability to 
correctly aim headlamps and to determine when aiming may be needed, 
such changes are not all that different from what has been used in 
Europe for decades. However, even with these features, European 
vehicles are also required to have headlamp aiming knobs or levers 
inside the passenger compartment so that drivers may move the headlamp 
aim downward to compensate for vehicle loading conditions. More 
recently, as a condition for allowing HID headlamps in Europe, these 
lamps must be installed only when automatic leveling (aiming) and 
automatic low beam washing and/or wiping is installed. European 
regulatory bodies have determined that automatic leveling and washing 
would help reduce the potential for glare from these headlamps that are 
specifically allowed to have higher beam performance than current 
halogen headlamps. The rationale behind the automatic washing is that, 
in general, a lamp with higher luminance is more adversely affected by 
dirt on the lens, resulting in more light directed toward the glare 
zone. In the U.S., because HID headlamps have been designed to comply 
with the existing required intensity performance, and not some new, 
higher performance as in Europe, there appeared to be no need for 
manufacturers to seek changes to introduce HID headlamps into the 
market nor for NHTSA to prevent them from being introduced.
    Question 6: Should the U.S. adopt the HID glare control measures of 
automatic leveling and washing that have been adopted by Europe? Please 
identify the data and analyses that support your views. What costs 
would be incurred to do so?
    Question 7: Should the U.S. adopt the driver operated manual 
headlamp leveling for halogen and/or HIDs that has been the norm in 
Europe? Is there evidence that leveling devices are used (and used 
properly) by many drivers? What would the costs be from adopting these?
    Another aspect of glare is whether NHTSA should reduce glare at the 
expense of seeing down the road. Comments and letters over the years 
have been mixed. Some people want ``better'' headlamps, meaning ones 
that will serve them better for seeing at night. Others state that the 
glare from headlamps is so bad that we should all be required to use 
the same headlamps that we had in the 1960's. As stated earlier, NHTSA 
and other governments, as well as lighting researchers have searched 
for the correct balance between roadway illumination and glare. The 
perfect balance is of course different for each roadway because of the 
variability in geometry, ambient light and other factors, for each 
person because of age, visual acuity and other factors, and for each 
vehicle because of lamp mounting height, headlamp aim and other 
factors.
    Some lighting researchers have suggested that net visibility would 
be maximized if all drivers would use only upper beams. While this may 
sound incredible, it is based on findings that the increase in roadway 
illumination would provide greater benefit than the high glare from 
upper beams would take away. While this is an interesting observation, 
the driving experience at night would not likely be optimized, based on 
the volume of complaints of glare with current headlamps. This raises 
the issue of whether NHTSA's balance between glare and roadway 
illumination should move toward less glare even if that means less 
visibility of the roadway environment.
    The average age of our driver population increases every year. 
Older persons' eyes are more sensitive to glare, yet simultaneously, 
such drivers need more light to see down the road.
    Question 8: Because reducing glare might improve older persons' 
mobility, and improving roadway illumination may do so too, given the 
age trend, should the reduction of glare be a priority, even at the 
expense of some visibility?
    Question 9: To what extent do medical problems with eyes that are 
associated with aging, such as cataracts, and the current medical 
procedures such as Lasik, reduce or improve resistance to glare 
effects?
    A possible model for glare reduction would be to move toward the 
European beam pattern for headlamps. That headlamp beam pattern allows 
less glare than the current U.S. beam pattern, but it also offers less 
seeing distance and less visibility for road signs. NHTSA is not 
presently contemplating an adoption of the European standard because 
the roadway environment is quite different--Europe relies heavily on 
lighted signs, while the United States largely depends on vehicle 
headlamps to illuminate signs. Nevertheless, the U.S. beam pattern 
could move closer to the European beam pattern in response to concerns 
about glare.
    Question 10: Is it reasonable for the United States to sacrifice 
some visibility at night to address the glare problems identified by 
the driving public? Would a move closer to the European headlamp beam 
pattern effectively address glare concerns? Please provide any data 
that

[[Page 49604]]

are available on the glare with European headlamps. What would be the 
effects on visibility at night from switching to a more European beam 
pattern with its downward aim? Please provide available studies on the 
comparative visibility of roadway and sign targets with the current 
European and U.S. headlamp beam patterns, and on the safety tradeoffs 
between visibility and glare, and what the safety and cost consequences 
of those tradeoffs are.
    Question 11: What would be the cost impacts, if any, for lamp 
manufacturers if the U.S. headlamp beam pattern were changed for new 
lamps? Please provide a detailed breakdown of how that cost impact was 
estimated.
    Question 12: Is it conceptually feasible to produce a viable beam 
pattern by retaining test points needed to ensure adequate sign 
visibility in the U.S. while moving to European values and test points 
to reduce glare for other drivers? If feasible, might this beam pattern 
be adopted as a global standard?
    Question 13: Because NHTSA's funds for safety initiatives are 
finite and the agency must use its judgment in deciding which 
initiatives are the most appropriate, is it appropriate for NHTSA to 
initiate an effort to develop an updated balance between glare and 
roadway illumination from headlamps at this time? On the other hand, if 
NHTSA does not undertake such an effort now and the public's complaints 
about glare continue to increase, what are the likely consequences?
    Question 14: If NHTSA begins such an effort, should the desired end 
be a new beam pattern with the rest of the headlamp portions of the 
lighting standard retained largely intact, or should the agency aim for 
a vehicle-based performance standard that evaluates the performance of 
headlamps as installed on the vehicle? With this latter approach, 
vehicle manufacturers would have much greater freedom in choosing 
headlamp location and attributes. The agency's goal could be to simply 
turn on the vehicle's headlamps and shine them on a screen, and assess 
the performance of the headlamps as they will perform when used and 
seen by the American public. What would be the impact on vehicle and 
headlighting manufacturers from such an approach?

3.2  Headlamp Mounting Height Issues

    As noted above, the most direct way of addressing glare from light 
truck headlamps is to mandate lower mounting heights. As headlamps move 
higher, the most intense part of the beam moves closer to the height of 
mirrors and drivers' eyes in lower vehicles, typically cars.
    Question 15: Is there a reasonable policy rationale for addressing 
the glare to drivers of lower vehicles from higher-mounted headlamps by 
requiring changes to the lower vehicles? Please articulate that 
rationale as clearly and succinctly as possible.
    Assuming that the preferred approach is to address the problem on 
the vehicles with the higher-mounted headlamps, one might consider 
lowering the acceptable mounting height for headlamps.
    Question 16: Has the current 54-inch maximum mounting height for 
headlamps ever forced a vehicle manufacturer to modify the design of a 
light vehicle because the headlamps would have been too high? Please 
provide some details on the design and indicate the height at which the 
headlamps would have been mounted.
    Question 17: How often do ``refreshes'' and ``redesigns'' occur for 
LTVs? Please be specific as to the models and approximate sales volumes 
of the vehicles. For example, some LTVs such as SUVs appear to be on 
approximately the same styling/redesign cycle as passenger cars, while 
full-sized vans apparently are not. Please provide estimates of the 
costs that would be associated with lowering headlamp mounting heights 
if it were done during the normally-planned refresh or redesign over 
and above the cost of the refresh and redesign, and explain how those 
estimates were derived. Is there a lead time that would minimize the 
costs of lowering headlamp mounting heights on LTVs?
    Question 18: Assuming that NHTSA were to mandate lower headlamps on 
LTVs, and that a time frame were specified that minimized the costs, 
are there other design considerations NHTSA should be aware of in 
reviewing the SAE report suggesting a limit of 900 or 1000 mm? For 
instance, would the headlamps necessarily then be so low that they 
would interfere with the ground clearance or the bumper performance of 
LTVs? Please provide as much information as possible to support or 
explain the answer.
    There are two possible negative ramifications if the maximum 
allowable headlamp mounting height were lowered significantly, although 
the size of these negative ramifications is unclear. First, the ability 
to see retroreflective traffic signs could be modestly degraded. These 
signs depend on vehicle headlighting for their conspicuity and 
legibility. Second, detection distance will be modestly decreased. This 
could reduce the ability of vehicle operators to detect an obstacle in 
time to avoid hitting it.
    In past research when the detection of objects was studied in 
comparison with the mounting height of the headlamps, there was a 
detection loss noticed as the mounting height was decreased. For 
passenger cars, the general findings have been that, for every one inch 
the headlamp is lowered, the detection distance is decreased by 
approximately ten feet. Lowering light truck headlamps five inches 
could result in a loss of fifty feet of roadway visibility. It should 
be noted that roadway visibility would still be greater than passenger 
car roadway visibility because the lamps may still be higher than 
passenger cars lamps. Also, light trucks do not necessarily have 
different stopping distances than passenger cars. Consequently, there 
may be no safety reason that would need to be considered in such a 
decision.
    Question 19: Please comment on these and any other trade-offs of 
lowering the maximum mounting height. Is there a maximum permissible 
mounting height that would not significantly reduce the seeing afforded 
to vehicles with higher mounted headlamps, while significantly reducing 
the glare to drivers of lower vehicles? Because LTVs are increasingly 
being used as passenger vehicles, why should their seeing distance and 
stopping distance be different enough to make this a concern?

3.3  Discussion of HID Issues

    HIDs are beginning to become more prevalent in many vehicles. 
Overseas, they constitute a much higher percentage of production than 
in the U.S. HIDs appear to have an advantage of providing a beam 
pattern that is broader, more uniform, and modestly more intense, 
especially to the sides. Some halogen-based lamps behave this way, 
also, but it is generally more difficult to make such robust headlamps 
with the limited volume of light flux available from halogen bulbs. On 
the other hand, the HID bulbs with up to two to three times more 
available flux (2800 to 3200 lumen versus 1200 to 2300 lumen for 
halogen), would seem to have an abundant volume of light available. 
Based on various technical papers about HID headlighting, the 
technology offers significant styling freedom, and is able to sacrifice 
efficiency and still achieve a robust beam because there is so much 
light flux available. As mentioned above, European rulemakers, 
concerned about such high available flux, impose upon HID headlamps the 
requirement that they must have automatic aiming and cleaning.
    Also, NHTSA notes that HID light sources are being used for 
auxiliary lamps such as fog, low beam and

[[Page 49605]]

driving lamps that are just now appearing in the aftermarket, as well 
as for upper beams in OEM applications.
    Question 20: Do HID bulbs have too much light flux available for 
the roadway illumination task? If so, please discuss why and what could 
be done to resolve this.
    Question 21: How do HID headlamp lower beam patterns vary from 
halogen lower beam patterns? Do these differences necessarily result in 
higher levels of glare for other drivers?
    Question 22: The agency is interested in receiving comments 
regarding human factors issues surrounding the use of whiter (and/or 
bluer) light in headlamp systems, whether from HID or halogen bulbs, 
that has uneven spectral density emission performance as do HIDs. Have 
there been any studies done regarding HID light sources, whether with 
automotive, industrial, home or any other venue that addresses this 
uneven energy emission and its visual perception by people?
    Question 23: One theory is that drivers are attracted to HID 
headlamps because of the newness or different appearance. This theory 
suggests that drivers then end up staring into the HID headlamps. Is 
this type of behavior documented relative to automotive or any other 
type of lighting event? Is there some period that is necessary for the 
public to adapt to a new lighting technology, whether on vehicles or 
otherwise (for example during the introduction of HID street lighting)? 
Are there any safety or other consequences from that adaption period?
    Question 24: Are there any studies or data that support or disprove 
the claim that illumination that is closer to daylight in color 
provides vision improvements that could enhance driving safety in the 
myriad of driving conditions at night? Please discuss these.
    Question 25: Are there any studies or data that support or disprove 
the claim that illumination that is more yellow (or any other color) 
provides vision improvements that could enhance driving safety during 
inclement weather in day or night? Please discuss these.
    Question 26: Are the conventional photometry and color measurement 
methods specified in current industry consensus standards and national 
and international regulations appropriate for HID powered headlamps? 
Does it accurately predict glare or does it underestimate it? What 
alternative testing methods should be used?
    Question 27: Has there been any research on achieving a more 
uniform spectral power distribution from HIDs that would be similar to 
that of a heated metal filament? If so, please provide references and 
discuss. What would be the safety and economic consequences of a 
rulemaking change that mandates a more uniform spectral power 
distribution?
    Question 28: The UMTRI-99-36 study found that to be considered 
similar in glare perception by test subjects, the halogen lamp had to 
be about 1.5 times or 50 percent brighter than the comparable HID lamp. 
What would be the safety and economic consequences if HID headlamps 
were required to meet photometric intensity performance but limited to 
about two-thirds of that now permitted? Please explain how your answer 
is determined.
    Question 29: It is well understood that raising the mounting height 
of headlamps raises the most intense part of the headlamp beam up to 
where it is closer to causing glare problems for other, lower drivers. 
It is also well understood that HIDs afford significantly more light 
flux and this greater volume of light raises the potential for 
increasing glare for others. Based on these generally understood glare 
parameters, one would expect that manufacturers would be very cautious 
about installing HIDs in higher-mounted positions, because the 
likelihood of glare would seem to be very high. Nonetheless, HIDs are 
now offered on several LTVs such as the BMW X-5, Mercedes Benz ML 
series and in previous model years, the Oldsmobile Bravada. To allow us 
to better understand the current practices of manufacturers of trucks 
having HID headlamps as standard or optional equipment, What were the 
analyses of glare that you considered when deciding to use HIDs in 
these higher-mounted lamps and why did these analyses lead you to 
conclude that glare from these lamps was acceptable? Please provide 
copies of these analyses.
    Question 30: Given that HID light sources are being used in non-
headlamp applications such as fog, auxiliary low beam and driving, and 
for OEM upper beam, should NHTSA regulate any or all exterior lighting 
devices that use HID light sources on motor vehicles? If so, should the 
regulated aspects be the same as those required for the currently 
required lighting devices, or should these requirements be different, 
more constraining or less constraining. Which lighting devices should 
have the highest priority to regulate first?

3.4  Discussion of Glare from HID Look-alike Bulbs and Other Colored 
Headlamp Bulbs

    NHTSA has regulated headlamp bulbs since about 1983 by 
standardizing their interchangeability performance. Until about three 
years ago, colored bulbs other than those used for amber turn signal 
lamps were generally not available to the public. With HIDs, this 
changed. The specifications for halogen and HID light sources (bulbs) 
collected in NHTSA's public docket (NHTSA-98-3397) list a myriad of 
necessary interchangeability details including capsule coatings that 
are necessary for proper operation. One such coating is called a bulb 
cap or capsule cap or black cap. One of these was present on the very 
first bulb introduced in FMVSS No. 108 for headlamp use in 1983. It 
reduces glare by preventing light from the filament from being emitted 
toward the headlamp's lens. While not essential for all headlamp 
designs, the majority of those using this first bulb needed such a 
coating and bulb types designed specifically for low beam use almost 
universally have such a black cap.
    Since 1983, many other interchangeability specifications for many 
other headlamp bulbs have been introduced into federal law. Many have 
black caps. Until recently, none had any other specified coating, 
filter, tinting or shielding. There are two types of bulbs, HIR1 and 
HIR2, that have special durable infrared reflective coatings on the 
bulb capsule. These coatings exist to make the bulbs more efficient at 
producing light; focusing back on the filament heat energy that would 
otherwise be lost. This insulating effect permits the filament to 
operate at a higher temperature while using less electrical energy. 
Also there is an HID bulb that has a coating, dissimilar to a 
traditional black cap, but serving the same function. None of the 
listed bulbs have had any other coatings specified.
    Because coatings, filters, tinting, and shielding can adversely 
affect the light emission of bulbs, these, of necessity, have to be 
part of the original specification of a newly introduced headlamp bulb. 
There are two reasons for requiring these to be included with the 
bulb's original specifications. The first is so that in designing a 
headlamp's optics, headlamp designers can rely on the fact that bulbs 
sold for this headlamp will achieve the performance designed into it 
and required of it by FMVSS No. 108. The second is so that the headlamp 
will continue the same safe performance when replacement bulbs are 
purchased.
    Any changes to the original specification for a bulb that can 
affect the interchangeability performance can cause headlamps to 
perform poorly, such as emitting not enough roadway illumination or too 
much glare and having beam shape changes. As with

[[Page 49606]]

photography and the use of filters to alter photographic images, 
coatings, filters, etc., that alter the image of the bulbs filament 
will change headlamp performance. Coatings, filters and etc., can 
change the color of light, the intensity, the sharpness of filament 
image and, in some cases, make multiple images of the filament, 
appearing much like a double or triple exposure in a photograph. Any of 
these alterations could adversely affect a headlamp's performance.
    Marketers of auto parts began to sell colored headlamp bulbs to 
allow vehicles to appear to have the latest HIDs, at an affordable 
price. These bulbs began to show up on cars and trucks in early 1998, 
shortly after the introduction of HIDs on more expensive cars. Having 
noticed this, NHTSA lighting engineers who regularly participate in SAE 
Lighting Committee meetings asked committee members to discuss the 
science, engineering, optics and other aspects of these new bulbs. 
Those engineers were mostly ignorant of the existence of those bulbs in 
the U.S. market. Upon being shown one of the suspect bulbs, all were 
surprised by the orange metallic interference coating that was present 
on the entire surface of the bulb capsule, because they did not believe 
that it would allow a headlamp to perform properly. During that 
meeting, a test was performed on the bulb in a headlamp, comparing it 
to the OEM bulb for the headlamp. When set up in a photometry 
laboratory, the colored bulb reduced peak intensity in the seeing light 
area of the beam by two-thirds, and markedly increased the glare 
intensity in the area where preceding and oncoming drivers' eyes are 
typically located and the total volume of light emitted by the headlamp 
dropped by almost half. The beam emitted using the colored bulb, 
shining on a white measuring screen in the lab, showed a broad array of 
colors, ranging from white near the hot spot to reds, greens, golds, 
blues and magentas, in vast areas of the beam. It was remarkably 
different than the performance of an OEM bulb. While the laboratory at 
which the meetings were held did not test the colored bulb/headlamp 
combination for compliance with FMVSS No. 108, the plot of its 
intensities implied that it was incapable of complying. The plots of 
this testing of the head-lamp with the OEM bulb versus the colored one 
may be seen in Docket NHTSA-2001-8885-6.
    Since that time, NHTSA staff have asked and worked with SAE and 
other international organizations to develop a test procedure for 
objectively determining when a coating, filter, etc., would change a 
bulb's performance such that it would be unacceptable from a bulb/
headlamp interchangeability and performance perspective. Since that 
first meeting, the organizations have worked together to discuss the 
issue and potential methods to deal with it. A consensus test procedure 
and performance criteria have been developed that could be added to the 
specifications of headlamp bulbs. This would help to ensure that the 
color separations and the resulting multiple filament images would be 
minimized enough to provide a headlamp with uniformly strong white 
colored images of the filament and not introduce headlamp performance 
problems. The first formal proposal of that procedure was provided to 
the United Nations Economic Commission for Europe's Working Party on 
Lighting and Light Signaling. That procedure and its supporting 
information is provided in Docket NHTSA-2001-8885-5. Such a procedure, 
when used in the development of a new bulb should markedly help to 
reduce the introduction of glare and vision loss that might otherwise 
occur from the addition of coatings, filters, etc. Thus, if the 
specification of a coating and the use of this test were to be added to 
an existing bulb's specification as an optional method of building a 
complying bulb, coated bulbs might be readily evaluated to ensure that 
there would be no adverse effects on a headlamp's performance.
    Based on the work done to date by SAE members and their associates, 
it appears to be possible to have bulbs with coatings that provide 
whiter light and still achieve satisfactory headlamp performance even 
though none are specifically referenced by FMVSS No. 108. For years, 
under the provisions of Part 564, manufacturers of bulbs have had the 
opportunity to amend the original specifications of a headlamp bulb. 
This opportunity comes with the proviso that any adverse consequences 
of the amendment would be the responsibility of the manufacturer making 
the amendment. In this case, such an amendment could provide for an 
option that is a colored version (but still achieving the defined white 
light) of the original design. Such an amendment to a bulb's 
specifications would clarify that a coated version of an OEM bulb could 
be built and certified under FMVSS No. 108. The potential for such 
amendments that would be submitted by manufacturers wishing to sell 
coated bulbs has been discussed at numerous SAE meetings in the U.S. 
and at numerous GTB Meetings and at the Working Party for Lighting and 
Light Signalling (GRE) meetings overseas as mentioned and referenced 
above. However, possibly because of the proviso regarding the 
responsibility for the amendment, no manufacturer has taken the 
opportunity to use it to standardize any coated, filtered, tinted or 
colored bulbs.
    Question 31: Given the concern of commenters that ``whiter'' and 
``bluer'' mean more glare, should any halogen bulbs be permitted to 
have emitted light with altered color that is different than that 
emitted by a heated wire filament through a colorless, unfiltered, 
uncoated glass or quartz bulb envelope?
    Question 32: Alternatively, and less restrictively, should NHTSA 
reduce the allowable tolerance for the measurement of color within the 
defined definition of the color white such that bulbs will emit color 
traditionally provided by halogen bulbs with colorless, coating-less, 
filter-less capsules? Would the procedure proposed to the United 
Nations Economic Commission for Europe's Working Party on Lighting and 
Light Signaling Docket (see NHTSA-2001-8885-5) be a reasonable one? 
Would this test performance resolve all performance problems associated 
with coatings, filters, tintings, and shields that are not part of the 
original specifications?
    Question 33: What safety value do any of these colored bulbs have? 
If there are any safety claims made, please provide the data and 
studies that substantiate those claims. If there are safety claims, 
provide an analysis of how those claims offset the possible disbenefit 
of increased glare.
    Question 34: If there are substantiated safety claims that 
overwhelmingly offset the glare disbenefits, should NHTSA mandate these 
colored bulbs, or just allow them? Would mandating these bulbs ensure 
greater safety benefit to the public than the public pays in 
differential cost for these versus uncolored bulbs?
    Question 35: If there are no substantiated positive or negative 
safety claims, should NHTSA prohibit these colored bulbs? What 
justification is there for being so performance or design restrictive?
    Question 36: Given the results of recent research documented in 
UMTRI 2001-9, indicating that discomfort glare ratings increase as the 
chromaticity moves toward the blue color range of the visible light 
spectrum, should NHTSA ban headlamp bulbs and headlamps that alter the 
color of the light emission?
    Question 37: Should all replaceable light sources be designed to 
conform the specifications of the standardized OEM

[[Page 49607]]

light sources, regardless of whether they are to be used as original or 
replacement equipment?
    Question 38: Because manufacturers appear to be reluctant to modify 
the standardized OEM design specifications to account for the 
advertised performance enhancements that some of the replacement light 
sources are claimed to have, should NHTSA restrict manufacturers 
ability to modify Part 564 submission information to simply those 
modifications that correct errors in previous submissions?
    Question 39: Many states have restrictions on the use of lamps on 
motor vehicles that have appearance similar to lamps required for 
emergency vehicles, i.e., lamps that have the emission of blue or red 
light. Has the enforcement of these state laws been affected since the 
introduction of replacement light sources that have bluish or other 
non-permitted colors?

3.5  Discussion of Glare From Fog Lamps, Driving Lamp, and Auxiliary 
Low Beam Headlamps

    Fog Lamps, Driving Lamp, and Auxiliary Low Beam Headlamps are 
governed by many states' laws. Often the state laws reference SAE 
performance and installation standards set for these lamps. Because 
state laws regarding the installation and use of these lamps are not 
consistent, motor vehicle manufacturers have publicly stated that NHTSA 
should regulate front fog lamps. Because of the complaints of glare, 
NHTSA has stated in the past that it is inclined to do that for safety 
reasons, pending the development of the world-wide harmonized front fog 
lamp standard. Complaints do not always specifically identify fog lamps 
as the cause of glare; complaints are often about extra headlamps. 
Because aftermarket sales of auxiliary lamps, including fog lamps, 
appear to be increasing, it is possible that some of the complaints 
concerning front mounted lamps are about auxiliary lamps other than 
front fog lamps. Currently, European and other regional regulations 
specifically deal with front fog, driving and rear fog lamps. In these, 
there is not an auxiliary low beam lamp defined; it appears to be 
uniquely North American.
    Question 40: Should NHTSA regulate any of these auxiliary lamps? If 
so, which ones, and why?
    Question 41: For fog lamps, should NHTSA adopt either or both of 
the existing SAE and the ECE performance requirements for this lamp? In 
the absence of any newer fog lamp standards, should NHTSA propose a new 
standard based on the recent, efforts of SAE and ECE? Should NHTSA 
propose switching, wiring, and aiming hardware performance that, to the 
extent possible, reduces the incidence of fog lamp abuse? Please 
provide support for your answers and recommendations.
    Question 42: Should NHTSA regulate any of the other auxiliary lamps 
to minimize, to the extent possible, aberrant performance and misuse? 
If so, should NHTSA adopt either or both of the SAE and the ECE 
performance requirements for these lamps? In the absence of any newer 
auxiliary lamp standards, should NHTSA propose new standards? Should 
NHTSA propose switching, wiring, and aiming hardware performance, that 
to the extent possible, reduces the incidence of their abuse? Please 
provide support for your answers and recommendations.

3.6  Discussion of Voltage to Headlamp

    Is there anything that should be done about the problem of higher 
than specified lighting intensity that is bound to occur on motor 
vehicles in service? Certainly, NHTSA testing the headlamp's 
illumination performance at a voltage higher than 12.8 volts would 
ensure that future designs of headlamps would operate in the real world 
at a performance level closer to their tested level. However, their 
performance would still vary because of the varying voltage present in 
any particular vehicle. Nevertheless, this solution would be a 
relatively inexpensive way to moderate the upward creeping intensity 
and attendant glare that it can produce.
    Alternatively, providing a constant voltage to headlamps would make 
their performance be virtually the same as that achieved when they are 
tested. The effect would be that, regardless of the vehicle's 
performance, the headlamps would provide the intended illumination and 
the measured levels of glare. There would be an increase in vehicle 
purchase cost for this solution, however, because an electronic module 
that can perform this constant voltage supply would be required. The 
installed price of this module on a new vehicle would be similar to 
that of the modules used for many current daytime running lamps, 
typically less than $20.
    Question 43: Should NHTSA require a standardized voltage be applied 
to headlamps when they are operating on motor vehicles in service?
    Question 44: What is the actual cost of providing such solutions 
for bringing on-vehicle headlamp intensity back in line with what is 
specified for them in the laboratory? Provide an analysis of the source 
of these costs to justify your answer.
    Question 45: What voltage levels will future vehicles provide to 
headlamps if left unregulated by FMVSS No. 108? Provide information and 
data to support your prediction.
    Question 46: Because higher voltages also shorten filament lamp 
life markedly, what are the costs and benefits to the public from 
having headlamp bulbs last longer than they would otherwise? What are 
the cost savings to vehicle manufacturers from averting warranty costs 
that normally occur because of shortened bulb life? Are both of these 
savings more than the cost of providing a constant voltage to 
headlamps? Should NHTSA amend FMVSS No. 108 to require such constant 
voltage?

Rulemaking Analyses and Notices

Executive Order 12866 and DOT Regulatory Policies and Procedures

    This request for comment was not reviewed under Executive Order 
12866 (Regulatory Planning and Review). NHTSA has analyzed the impact 
of this request for comment and determined that it is not 
``significant'' within the meaning of the Department of 
Transportation's regulatory policies and procedures. The agency 
anticipates if a proposal and ultimately a final rule should result 
from this request for comment, new requirements would apply to the 
applicable vehicles and items after the specified implementation date. 
The request for comment seeks to determine the ramifications of 
requiring a lower maximum mounting height of headlamps on passenger 
cars and multipurpose passenger vehicles. It seeks to learn more about 
claims and causes of glare, to determine whether any kinds of 
constraints on HID headlamps should be implemented. It seeks 
information on whether to specifically allow or prohibit purposefully 
colored headlamp bulbs. It seeks to determine whether and how to 
regulate auxiliary front and rear lamps that are intended or claimed to 
enhance safety under certain limited driving conditions.

How do I prepare and submit comments?

    Your comments must be written and in English. To ensure that your 
comments are correctly filed in the Docket, please include the docket 
number of this document in your comments.
    Your comments must not be more than 15 pages long (49 CFR 553.21). 
We established this limit to encourage you to write your primary 
comments in a concise fashion. However, you may

[[Page 49608]]

attach necessary additional documents to your comments. There is no 
limit on the length of the attachments.
    Please submit two copies of your comments, including the 
attachments, to Docket Management at the address given at the beginning 
of this document, under ADDRESSES.

How can I be sure that my comments were received?

    If you wish Docket Management to notify you upon its receipt of 
your comments, enclose a self-addressed, stamped postcard in the 
envelope containing your comments. Upon receiving your comments, Docket 
Management will return the postcard by mail.

How do I submit confidential business information?

    If you wish to submit any information that you do not want to be 
made public, under a claim of confidentiality, you should submit three 
copies of your complete submission to the Chief Counsel, NHTSA, at the 
address given at the beginning of this document under FOR FURTHER 
INFORMATION CONTACT. This submission must include the information that 
you are claiming to be private, that is, confidential business 
information. In addition, you should submit two copies from which you 
have deleted the private information, to Docket Management at the 
address given at the beginning of this document under ADDRESSES. When 
you send a comment containing information claimed to be confidential 
business information, you should include a cover letter that provides 
the information specified in our confidential business information 
regulation, 49 CFR Part 512.

Will the agency consider late comments?

    We will consider all comments that Docket Management receives 
before the close of business on the comment closing date indicated at 
the beginning of this notice under DATES. To the extent possible, we 
will also consider comments that Docket Management receives after that 
date. If Docket Management receives a comment too late for us to 
consider in developing a proposed response to these glare issues, we 
will consider that comment as an informal suggestion for future 
rulemaking action.

How can I read the comments submitted by other people?

    You may read the comments received by Docket Management at the 
address and times given near the beginning of this document under 
ADDRESSES.
    You may also see the comments on the Internet. To read the comments 
on the Internet, take the following steps:
    (1) Go to the Docket Management System (DMS) Web page of the 
Department of Transportation (http://dms.dot.gov/).
    (2) On that page, click on ``search.''
    (3) On the next page (http://dms.dot.gov/search/), type in the 
four-digit docket number shown at the heading of this document. 
Example: if the docket number were ``NHTSA-2001-8885,'' you would type 
``8885.''
    (4) After typing the docket number, click on ``search.''
    (5) The next page contains docket summary information for the 
docket you selected. Click on the comments you wish to see.
    You may download the comments. Although the comments are imaged 
documents, instead of the word processing documents, the ``pdf'' 
versions of the documents are word searchable. Please note that even 
after the comment closing date, we will continue to file relevant 
information in the Docket as it becomes available. Further, some people 
may submit late comments. Accordingly, we recommend that you 
periodically search the Docket for new material.

    Authority: 49 U.S.C. 322, 30111, 30115, 30117, and 30166; 
delegation of authority at 49 CFR 1.50.

    Issued on: September 25, 2001.
Stephen R. Kratzke,
Associate Administrator for Safety Performance Standards.
[FR Doc. 01-24430 Filed 9-27-01; 8:45 am]
BILLING CODE 4910-59-P