[Federal Register Volume 63, Number 121 (Wednesday, June 24, 1998)]
[Proposed Rules]
[Pages 34350-34356]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 98-16808]


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DEPARTMENT OF TRANSPORTATION

National Highway Traffic Safety Administration

49 CFR Part 571

[Docket No. NHTSA 98-3967; Notice 1]
RIN 2127-AG88


Federal Motor Vehicle Safety Standards; Lamps, Reflective 
Devices, and Associated Equipment

AGENCY: National Highway Traffic Safety Administration (NHTSA), DOT.

ACTION: Notice of proposed rulemaking.

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SUMMARY: This document proposes to amend the Federal motor vehicle 
safety standard on lighting to relieve design restrictions that may 
inadvertently prevent the implementation of certain new-technology 
light sources in motor vehicle lamps. These are light emitting diodes 
(LEDs) and miniature halogen bulbs. The standard would be amended to 
add two paragraphs reflecting SAE specifications for measurement of 
photometrics in taillamps and in certain stop and turn signal lamps 
with more than one lighted section and for LED heat testing. The agency 
issued a proposal on these issues in 1994, but terminated rulemaking 
the following year. These issues are being revisited in response to a 
petition for rulemaking from Reitter & Schefenacker GmbH & Co. KG.

DATES: Comments are due on the proposal August 10, 1998. The proposed 
effective date is one year after publication of the final rule. 
However, the agency is soliciting comments on whether optional 
compliance should be allowed in advance of that date.

ADDRESSES: Comments should refer to the docket number and notice 
number, and be submitted to: Docket Management, Room PL-401, 400 
Seventh Street, S.W., Washington, D.C. 20590 (Docket hours are from 
10:00 a.m. to 5:00 p.m.)

FOR FURTHER INFORMATION CONTACT: Chris Flanigan, Office of Safety 
Performance Standards (202-366-4918).

SUPPLEMENTARY INFORMATION:

Introduction

    On April 8, 1994, the agency published a notice of proposed 
rulemaking (NPRM) to amend Federal Motor Vehicle Safety Standard No. 
108, ``Lamps, Reflective Devices, and Associated Equipment,'' to 
relieve design restrictions that may inadvertently prevent the 
implementation of certain new-technology light sources in lamps (59 FR 
16788). These new lamp technologies include light-emitting diodes 
(LEDs), miniature halogen bulbs, and other light sources with a limited 
luminous flux. Luminous flux is the total light emitted from a light 
source, in all directions. All these light sources will be referred to 
as ``limited flux light sources'' hereafter. Compared with light 
sources with traditional filaments, non-filament light sources such as 
LED and miniature halogen light sources emit only a fraction of the 
luminous flux of filament light sources. Consequently, to achieve the 
same performance as a single traditional filament light source, it is 
necessary to use multiple non-traditional light sources, hence their 
identification as ``limited flux light sources.'' In the 1994 proposal, 
the agency asked for comment on how it might specify a means of 
determining the number of equivalent lighted sections for lamps 
equipped with these new lamp technologies. The agency wishes Standard 
No. 108 to be responsive to new technologies and to remove inadvertent 
impediments to their implementation. The notice also proposed a 
performance requirement to determine an LED lamp's ability to maintain 
photometric compliance under increased temperature conditions.
    The requirements contained in Standard No. 108 for signal lamps are 
based on Society of Automotive Engineers (SAE) Standards and 
Recommended Practices that were developed to accommodate incandescent 
bulbs, i.e., those with filaments. These were developed many years 
before LEDs when incandescent bulbs were the only light sources in use 
at that time. New lighting source technologies have arisen that have 
fundamentally different characteristics than incandescent lamps. Thus, 
it is difficult to apply the specifications of Standard No. 108 to the 
new

[[Page 34351]]

technologies. Attempts to do so have revealed some ambiguities and 
inconsistencies with the design and method of performance of the new 
technologies. The SAE standards for taillamps, and for stop and turn 
signal lamps on vehicles with an overall width of less than 80 inches, 
treat a lamp having one bulb as a lamp with a single lighted section, a 
lamp having two bulbs as one with two lighted sections, and a lamp with 
three or more bulbs as one with three lighted sections. Thus, the 
standard requires that, if a lamp uses three or more light sources, it 
must meet the minimum photometric requirements of a three-compartment 
lamp. This becomes a problem when a manufacturer intends to make an LED 
lamp which is equal in size to a conventional incandescent lamp with 
one or two lighted sections. To make such an LED lamp, many more than 
three LEDs are needed. Typically, 15 or more are necessary. Thus, when 
there are three or more LEDs in one compartment, under current 
interpretations regarding the light output of one, two, and three-
lighted section lamps, those LEDs must achieve the light intensity of a 
lamp with three lighted sections to comply with Standard No. 108. This 
results in a lamp which is overly bright in comparison with a 
similarly-sized single bulb/single lighted section incandescent lamp. 
This is because this lamp would be approximately one-third the size of 
a lamp with three lighted sections, and must achieve about 1.3 times 
the intensity of a lamp with a single lighted section. Further, it is 
unnecessarily expensive because a greater number of LEDs must be used 
to achieve the intensity of three lighted sections than would otherwise 
be used to achieve the intensity of a single lighted section.
    In their comments on the 1994 NPRM, the American Automobile 
Manufacturers Association (AAMA), Ford Motor Company (Ford), and 
General Motors Corporation (GM) all indicated that they thought it was 
premature for the agency to specify unique requirements for lamps 
equipped with these light sources until studies could be completed to 
assess concerns regarding possible perceptions with respect to their 
brightness. AAMA wanted to gather data on intensity, brightness, and 
dimensional features (e.g., aspect ratio--the ratio of length to 
height) of signal and marker lamps of recent model vehicles. Other 
commenters could not reach a consensus on an appropriate specification.
    Based on these comments, the agency concluded that, although the 
lighting industry had a solution acceptable to it, there was a great 
uncertainty within the vehicle industry about the best method of 
regulating the photometric requirements of non-traditional light 
sources for signal and marker lamps. In view of this uncertainty on the 
part of the automotive industry, the agency terminated the rulemaking 
on June 19, 1995 (60 FR 31939), stating that it might reinitiate it at 
a time when an outcome that would be more acceptable was a prospect. 
The termination also covered the proposed performance requirement to 
determine an LED lamp's ability to maintain photometric compliance 
under increased temperature conditions, as NHTSA anticipated that the 
industry, in a short time, would develop a test procedure more 
representative of the real world.
    On February 6, 1997, Reitter & Schefenacker GmbH & Co. KG 
(Schefenacker), a lighting manufacturer, petitioned the agency to 
revisit this issue. Schefenacker stated that Standard No. 108 is design 
restrictive and a burden for vehicle and signal lamp manufacturers 
because it makes LED signal lamps unnecessarily expensive and, in 
certain cases, too large to fit on the vehicle. This is because, in 
nearly all cases, lamps which use LEDs must meet the requirements for a 
three-section lamp. This imposes design restrictions because the lamps 
must be made larger to accommodate the additional LEDs. According to 
Schefenacker, this can increase the cost of the lamp by 50 percent. The 
petitioner also stated that, due to the increased number of LEDs in the 
lamps, the brightness is increased and may cause discomfort glare to 
following drivers. Schefenacker argued that if Standard No. 108 were 
amended to account for the different characteristics of LEDs, the size 
of lamps would be comparable to conventional lamps and there would be 
no fundamental change in appearance. Based on these arguments, NHTSA 
has decided to reopen rulemaking.
    The second issue addressed in the 1994 NPRM was the effect of heat 
on the luminous flux of LEDs. Unlike incandescent light sources, the 
luminous flux of LEDs drops rapidly as their temperature increases. 
This could be a problem if the lamps are illuminated for a long period 
of time, such as can occur with use of the hazard warning system or 
when stop lamps are applied in dense urban traffic. LEDs can also 
become heated if they are used in an environment with a relatively high 
ambient temperature. The agency's position on this issue has been that 
LEDs should conform at any temperature in the motoring environment. The 
SAE addresses this characteristic in SAE Recommended Practice J1889 
JUN88 ``L.E.D. Lighting Devices.'' This specification contains tests 
which test the performance of LEDs at higher temperatures.

Background

Limited Flux Light Sources

    The adoption of requirements for a center high-mounted stop lamp 
(CHMSL) has resulted in some creative solutions to the problem of 
integration of the lamp into the overall vehicle design. To reduce the 
size and obtrusiveness of the lamp, while maintaining the photometric 
conformance called for by Standard No. 108, manufacturers began to 
resort to smaller light sources. Limited flux light sources have been 
used in CHMSLs (because the standard contains no light source 
specifications for CHMSLs, any light source is permissible).
    However, the application of Standard No. 108 to lamps with limited 
flux light sources raises the question as to how to determine 
compliance with photometric requirements, specifically, how to define a 
lighted section. SAE Standards J586 FEB84 and J588 NOV84 incorporated 
by reference and applying to stop lamps and turn signal lamps on 
vehicles whose overall width is less than 2032 mm (80 inches), and SAE 
Standard J585e September 1977, applying to taillamps on all vehicles, 
specify requirements to be met by lamps with one, two, and three 
lighted sections. These standards are based upon incandescent bulb 
technology where requirements are generally met by using one bulb for 
each lighted section. The specification of 32 candela per lighted 
section is based upon the highest output of contemporary incandescent 
signal lamp bulbs. When requirements are intended to be met by limited 
flux light sources, the light output specification cannot be provided 
by a single light source, but must be provided by multiple light 
sources. However, current interpretations of what is necessary to 
comply with Standard No. 108 do not contain any differentiations based 
upon the type of light source, only upon the number of light sources, 
because the SAE standards have not contained any differentiations based 
on type of light source. Thus, if 20 LEDs provide the same illumination 
as a single filament bulb, a lamp equipped with the former is 
considered a lamp with three lighted sections for purposes of 
compliance, not a single-section lamp. To meet the photometric 
requirements for three-

[[Page 34352]]

section lamps, manufacturers must use an overly bright and costly array 
of LEDs.
    Schefenacker suggested three ways to address the problem. The first 
is to require lamps which use limited flux light sources to meet the 
photometric requirements of lamps with one lighted section regardless 
of the size of those lamps. The second is to use luminous flux limits 
by summing the luminous flux of LED's, thereby providing some method of 
equating the number of LEDs to the equivalent number of lighted 
sections: lamps with up to 32 candlepower (cp) would be considered as 
having one section; between 32 cp and 64 cp, as having two sections; 
and greater than 64 cp, as having three sections. A lamp's candlepower 
would be determined by summing the rated candlepowers for each 
individual light source in a lamp. For example, if a lamp used 40 LEDs, 
each with a rated candlepower of one cp, the lamp's candlepower would 
be 40 cp. Under this approach to the problem, the lamp would be 
considered to be a lamp with two lighted sections because the sum of 
the rated candlepower is between 32 and 64 cp. The third way is to use 
size-dependent criteria for determining the equivalent number of 
lighted sections. A lamp would be regarded as having the equivalent of 
one lighted section if the maximum horizontal or vertical linear 
dimension of the effective projected luminous lens area of the lamp is 
less than 150 millimeters (mm), two lighted sections if the dimension 
is 150-300 mm, and three lighted sections if the dimension is greater 
than 300 mm. This is the specification which is contained in SAE J1889 
and which was also proposed in the 1994 NPRM.
    Hewlett-Packard, a manufacturer of LEDs, recommended another method 
to deal with this issue. Under this approach, which the agency proposed 
in the 1994 NPRM as an alternative, lamps using LEDs or other limited 
flux light sources need only meet the intensity specifications for 
single-section lamps, provided that: (a) the maximum horizontal or 
vertical distance between the apparent optical centers of the closest 
adjacent light sources within the lighted section of the lamp are not 
greater than 2.0 centimeters (cm); and (b), if there were more than one 
lighted section, there is not more than 2.0 cm between the edge of the 
closest adjacent lighted sections. Measuring the distance between the 
optical centers would therefore provide an objective method for 
determining whether there is more than one lighted section.
    Arguing that the LED requirements in SAE J1889 were far too 
limiting from standpoints of cost and styling, Hewlett-Packard 
explained the rationale for its recommendation as follows:

    SAE's higher intensity requirements for multiple compartment 
lighting devices stems from the fact that the apparent 
``brightness'' of any light emitting area is not solely dependent on 
the intensity measured, but also the area of the emitter. Any two 
light sources can exhibit the same intensity measurement, while the 
source with the smaller light emitting area will appear brighter to 
the human eye. This is due to the nature of the human eye's 
perception of light, and is frequently taken into account in the 
design of ``sterance [or brightness] matched'' displays in the 
information display industry. This effect is also demonstrated by 
the response of consumers who mention that LED high mount stop lamps 
are very bright, when in fact they are designed to meet the same 
intensity requirements as incandescent high mount stop lamps. The 
difference is in the light emitting area. The smaller the light 
emitting area for a given intensity, the brighter the appearance to 
the human eye.
    With this in mind, the proposed change in [Standard No. 108] 
will guarantee that at least a minimum level of brightness, or 
sterance, will be maintained regardless of length, area, or shape of 
the lighting device. This will allow lighting designers to fully 
realize all the benefits of styling and flexibility of LED lighting 
and provide a conspicuous and understandable signal device whether 
it be in tail, stop, or turn mode.

    To the agency's knowledge, the vehicle industry has not come to a 
consensus on how to define the number of lighted sections in a lamp 
since NHTSA published the 1994 NPRM. Because of the multitude of lamp 
designs (different shapes, sizes, lens optics, etc.) installed in on 
today's vehicles, it may take more time to determine the best method. 
However, notwithstanding the absence of a consensus, the agency 
believes that it should move forward with rulemaking. Unlike 1994, when 
the agency issued a proposal on its own initiative, this time it is 
issuing a proposal in response to a petition from a member of the 
industry.

Agency Proposal Regarding Limited Flux Light Sources

    This notice outlines the advantages and disadvantages of its 
proposed solution, as well as those of three alternative solutions 
suggested above. The public is invited to submit other recommendations. 
However, the agency wishes to make clear that if other recommendations 
are made and if they are substantially different from those which are 
proposed, their consideration could necessitate the issuance of a 
supplemental proposal and thereby prolong the rulemaking process. In 
any event, the agency plans to proceed to a final rule to resolve this 
issue.
    The following is a discussion of possible solutions and their 
advantages and disadvantages:
    1. At the present, the agency tentatively concludes that the most 
logical solution is the one that it is proposing: the adoption of size-
dependent criteria for determining the equivalent number of lighted 
sections. A lamp would be regarded as having the equivalent of one 
lighted section if the maximum horizontal or vertical linear dimension 
of the effective projected luminous lens area of the lamp is less than 
150 millimeters (mm), two lighted sections if the dimension is 150-300 
mm, and three lighted sections if the dimension is greater than 300 mm. 
This is essentially the same specification contained in SAE J1889 and 
proposed by NHTSA in 1994. Schefenacker, too, recommended this 
solution. This specification was developed and accepted by the lighting 
industry for this very purpose. Further, adopting this specification 
would satisfy Federal requirements (i.e., National Technology Transfer 
and Advancement Act of 1995 and Office of Management and Budget 
Circular A-119, Federal Participation in the Development and Use of 
Voluntary Consensus Standards and in Conformity Assessment Activities ) 
concerning Federal agencies' use of industry consensus standards except 
where inconsistent with law or otherwise impractical . Adopting 
accepted industry consensus standards eases the regulatory burden on 
manufacturers since many of them are already meeting them. However, 
given that SAE J1889 was adopted in 1988, an important question is 
whether the parameters remain representative of lamp designs that are 
in use now and those that are contemplated in the foreseeable future. 
NHTSA invites comments on this issue.
    2. Another possible solution suggested by Schefenacker is that all 
lamps which use limited flux light sources meet the photometric 
requirements of lamps with one section. This specification assumes that 
a cluster of these bulbs will be used to achieve the same effect as one 
incandescent bulb. If, however, these bulbs are grouped with the 
intention of achieving the same effect as a two-section lamp with two 
incandescent bulbs, the lamp may be too dim. If a lamp with two or more 
sections is intended, the number of limited flux light sources which 
would normally be used for a one-section lamp could be spread out over 
the area of the multisection lamp. Such a lamp would comply with SAE 
J1889 and be less costly, but it would appear to observers to be only 
about half as bright as lamps that use normal

[[Page 34353]]

incandescent bulbs. This could present a problem in fog because the 
already-diffuse light emitting from the lamp would be diffused further 
by the fog.
    3. Another alternative suggested by Schefenacker would be to use 
the luminous flux limits to determine the number of lighted sections. 
Lamps with up to 32 candlepower (cp) would be considered as having one 
section; between 32 cp and 64 cp, as having two sections; and greater 
than 64 cp, as having three sections. A lamp's candlepower would be 
determined by summing the rated candlepower for each individual light 
source in a lamp. For example, if a lamp used 40 LEDs, each with a 
rated candlepower of one cp, the sum would be 40 cp. Under this 
suggested way of addressing the problem, the lamp would be considered 
to be a two-section lamp because the sum of the rated candlepower is 
between 32 and 64 cp. This is an easily enforceable specification for 
some light sources, typically miniature halogen bulbs, as the ratings 
of the bulbs could be easily determined. Thus, each lamp would be 
clearly defined by the bulbs it is designed to use.
    However, there may be some problems with this approach for 
manufacturers which produce LED and neon light sources. If the summed 
numbers do not represent the real world, or because of a lack of 
standardization, it is possible that this approach would not be viable. 
NHTSA therefore requests comments as to the representativeness of the 
numbers. This approach may also cause problems in the design of lamps. 
For example, if the optimal design for a certain lamp calls for 33 
LEDs, rated at one cp per LED, the lamp would be required to comply 
with the two-section specifications. This is because the sum of the 
candlepower of the LEDs would total 33 cp, which is between 32 and 64 
cp. To comply with the two-section requirements, more LEDs may have to 
be added to achieve the required level of brightness. This may make the 
lamp overly bright and costly, the same situation that exists today. 
However, the agency is interested in having comments on all the 
suggestions made by Schefenacker as discussed above.
    4. Another alternative submitted by Hewlett-Packard was also 
proposed in the 1994 NPRM. Under this alternative, lamps using LEDs or 
other limited flux light sources need only meet the intensity 
specifications for single-section lamps, provided that: (a) the maximum 
horizontal or vertical distance between the apparent optical centers of 
the closest adjacent light sources within the lighted section of the 
lamp are not greater than 2.0 centimeters (cm); and (b), if there were 
more than one lighted section, there is not more than 2.0 cm between 
the edge of the closest adjacent lighted sections.
    This alternative would provide maximum flexibility for 
manufacturers who use LEDs because they could use many configurations. 
However, miniature halogen bulbs may be too large to put in some 
intricate configurations for lamp design, especially for manufacturers 
of LEDs such as Hewlett-Packard. Further, this approach may provide too 
much flexibility. For instance, it would allow a manufacturer to write 
its name in script form in lights, provided each light source was 
within 2.0 cm of another other, and thus have it considered a single-
section lamp. A specification such as this could allow too much 
flexibility and result in lamps which are so unconventional in 
appearance that they would be likely to be misunderstood by the public. 
One goal of Standard No. 108 is to provide lamps which are fairly 
universal in appearance for assuring quick recognition of stop and turn 
signal lamps. This can be critical in many situations such as abrupt 
stops and turns. Nevertheless, the agency wishes to have informed 
opinion on this approach, and invites the public to comment on it.
    Within the past year, the agency received a suggestion from the 
Chair and a member of the SAE Heavy Duty Lighting Standards Committee. 
Addressing the issue of LEDs and lighted sections, they recommended 
amending Standard No. 108's paragraph on definitions.
They would add a definition for ``composite light source:''

    Composite light source means a device consisting of two or more 
adjacent light sources, with or without common or individual primary 
reflectors, integrated and powered by one electronic module or 
electric circuit designed to function as a single, independent unit 
providing single or multiple lighting functions. The device forms an 
indivisible joined unit which cannot be dismantle without rendering 
it completely unusable.

They would also change the current definition of ``multiple compartment 
lamp'' to read:

    Multiple compartment lamp means a lamp which provides its 
lighting function using two or more lighted areas, each of which is 
lighted by a separate, composite, or single light source, and which 
are joined by one or more common parts, such as a housing or lens.

    While these definitions would help solve problems for lamps using 
LEDs, they would not resolve issues relating to miniature halogen lamps 
or other miniature light sources. The last sentence of the definition 
suggested for ``composite light source'' specifies that the unit be 
indivisibly joined and not able to be dismantled without rendering it 
useless. Lamps that use LEDs generally incorporate a circuit board with 
all the LEDs permanently attached to it. However, other miniature light 
sources use bulbs that can be individually replaced. NHTSA believes 
that its rulemaking should take into account all miniature light 
sources. However, the agency invites comments on the approach discussed 
above.
    A GM safety office employee has asked a staff member of the agency 
to consider an issue that is related to this rulemaking. Standard No. 
108 requires that failure of a turn signal lamp be indicated to the 
vehicle operator. In many turn signal systems, when a failure occurs, 
the turn signal indicator light ceases to flash and begins to operate 
in a steady-burning mode. The question arises as to how many LEDs in a 
turn signal lamp using LEDs must fail in order for the failure to be 
indicated to the driver. Certainly, a failure of one or two LEDs out 
of, say, 40 ought not to create a noticeable decrease in turn signal 
intensity. However, a level could be reached which could significantly 
affect the lamp's effectiveness, when 15, 20, or more LEDs cease to 
function. The agency views this rulemaking as an opportune and 
appropriate time to solicit comment on this issue, and asks that each 
person wishing to comment address it specifically.
    Finally, there is the possibility of regulating the luminance of 
the lamp itself, without reference to the number of sections or light 
sources. Performance standards could be adopted that would assure the 
lamps would have a maximum and minimum luminance. While such a change 
might be difficult, with no enhancement of safety, this approach could 
allow design flexibility that could reduce lamp and vehicle costs. The 
agency, therefore, is inviting comments on this possibility and how it 
might be developed and implemented.
    In accordance with the discussion above, NHTSA is proposing the 
addition of a new paragraph S5.1.1.23 to read:

    S5.1.1.23 Instead of being designed to conform to photometric 
requirements based on the number of lighted sections specified in 
SAE J586 FEB84, SAE J588 NOV84, and SAE J585e September 1977, as 
applicable, each stop lamp, turn signal lamp, and taillamp that is 
equipped with light-emitting diodes or other miniature light 
sources, and that needs more than one light source to achieve 
compliance with the photometric performance required of a single 
lighted

[[Page 34354]]

section, shall be designed to conform to photometric requirements 
based on the dimension of the effective projected luminous lens area 
for the function being tested. A lamp is regarded as having one 
lighted section if the maximum horizontal or vertical linear 
dimension of the effective projected luminous lens area of the lamp 
is less than 150 millimeters (mm), two lighted sections if the 
dimension is 150-300 mm, and three lighted sections if the dimension 
is greater than 300 mm.

Effective Projected Luminous Area

    At numerous places in Standard No. 108, there are requirements for 
the ``minimum effective projected luminous area'' of signal and marker 
lamps. This area is defined by the standard as being the area of the 
projection on a plane perpendicular to the lamp axis of that portion of 
the light-emitting surface that directs light to the photometric test 
pattern, and does not include mounting hole bosses, reflex reflector 
area, beads or rims that may glow or produce small areas of increased 
intensity as a result of uncontrolled light from small areas (\1/2\ 
degree radius around the test point). The rationale for area 
requirements is to ensure that the lamps' luminance is not too high, 
while reducing the light dispersion effect of dirt on the lens. This is 
especially important for larger vehicles that tend to be cleaned less 
often.
    In the case of lamps which use LEDs or other types of miniature 
light sources, the individual light sources each produce a narrow beam 
of light. Because of this, the individual light sources illuminate very 
distinct areas of the entire lamp lens. For example, looking at a 
single, circular tail lamp which uses 25 LEDs as its light sources, the 
narrow beam of each LED creates an appearance of 25 small illuminated 
circles within the larger circular lens. The area surrounding these 25 
illuminated circles appears to not be illuminated. However, based on 
informal conversations with a lamp manufacturer, on some lamps, if one 
were to cover the smaller circular areas on the lens where the LED 
beams are projected on the lens surface, there is a small amount of 
light that can be detected from the darker regions which are not 
covered. This small amount of light allows the lamp to comply with the 
minimum effective projected luminous area requirements, as the total 
light emitted is from the entire lamp surface.
    While lamps using miniature light sources may technically comply 
with the minimum effective projected luminous area requirements of the 
standard, the agency is concerned that dirt on the lens could easily 
negate the light emission from these interstices such that the lamp 
becomes markedly smaller in lens area for emitted light. That is, the 
minuscule amount of light emitted from the areas outside the beams of 
the light sources may not be enough to be seen in some conditions, such 
as driving in very bright sunlight or with mildly dirty lenses.
    The agency's concerns are even greater for some combination lamp 
designs using miniature light sources. In some lamp designs the stop, 
turn, and taillamp functions are incorporated into one lamp. For some 
of these lamps, only a fraction of the total number of light sources 
are illuminated for the taillamp signal. The taillamp function may 
utilize one-tenth of the miniature light sources that the stop or turn 
lamp uses. Again, industry testing of these turn signals has shown that 
there still is a small amount of light emitted from the entire lens 
surface. But, because of the smaller number of light sources being 
illuminated for some tail lamps, the likelihood is increased that the 
critical areas of the lamp could be reduced in output.
    The agency would like to have comments on this issue. Specifically, 
NHTSA wishes to have the view of commenters on whether lamps which use 
miniature light sources with narrow beams are more likely to have 
performance degraded than those lamps where the light is more evenly 
distributed over the lens. NHTSA would like comments on the quantum of 
light emitted outside the narrow beams of light from the miniature 
light sources and whether it is sufficient for the lamp to retain some 
functionality in case it is impaired by road contaminants. In addition, 
commenters should address how the minimum effective projected luminous 
area should be measured to account for the narrow beams of LED's and 
similar sources, and whether there should be requirements to distribute 
the light more evenly over the lens surface.

Heat Performance of LEDs

    In the 1994 NPRM, the agency proposed to adopt the text of SAE 
J1889 which specifies (paragraphs 3.1.5.2 and 3.1.5.3) a temperature 
condition for testing LED lamps to photometric maxima and minima. For 
measurements of the maximum photometrics, an unenergized test device is 
stabilized at the laboratory's ambient temperature, which is 23 
<plus-minus>5 degrees Celsius ( deg.C). It is then energized. The 
maximum values within 60 seconds of the initial ``on'' time are 
recorded. For measurements of the minimum requirements, an energized 
device is also stabilized within the same temperature range until 
either the heat buildup saturation has occurred, or 30 minutes has 
elapsed, whichever first occurs. Measurements are then taken of the 
already-energized lamp. However, this test procedure does not cause 
LEDs to reach the temperatures they could experience in very hot 
climates. Because of this, the industry asked the agency to defer 
rulemaking on this issue so that it could develop a test procedure 
which represents real world conditions. However, the industry has not 
moved forward on this issue, and the agency has decided to repropose 
the procedure.
    This procedure provides a simple method for testing the 
relationship between temperature and light intensity by having the 
lamps heat themselves. It does not replicate the environment in which 
lamps on motor vehicles must produce correct signals for the 
transmission of safety information. In the real world, lamps are heated 
by the environment, such as use on a hot day in Florida. It is 
conceivable that lamps could be placed in a heat chamber to simulate 
the environment and tested photometrically. However, this would not be 
practicable because of the expense of tests and their lack of 
repeatability. The SAE test represents a thoughtful and repeatable 
solution to this simulator. However, developing a practicable test 
procedure that replicated that environment would be problematic. NHTSA 
believes that a test procedure which represents real world conditions 
would be overly burdensome to the industry. Attempting to create such a 
procedure would require a heat chamber to heat the LEDs to a 
temperature that represents a very hot climate. If the lamp were to be 
placed in a heat chamber and heated, the lamp would have to be removed 
when it reached the desired temperature and mounted in the test device. 
During this interval, the temperature of the lamp would decrease, thus 
reducing the accuracy and repeatability of the test. To maintain the 
heat, the test device would have to be located in a large heat chamber. 
To create a test apparatus which could heat the LEDs, and also house 
the photometric equipment, would be very costly, assuming that the 
equipment would be accurate and reliable at such high temperatures. 
Also challenging is assuring that an optically correct window can be 
fitted to the chamber so that the lamp's beam can be projected to the 
intensity measuring equipment located outside the test chamber if that 
equipment cannot be located inside the chamber.
    To the agency's knowledge, the industry has not developed a 
procedure for testing the effects of temperature on LED lamps that is 
more representative

[[Page 34355]]

than that which is contained in SAE J1889 and that avoids the practical 
testing problems described above. Therefore, NHTSA is proposing that 
Standard No. 108 be amended to include the test procedure contained in 
SAE J1889. Although it does not represent the worst case conditions of 
the driving environment, it is a standard which was created by the 
industry to test LEDs' ability to maintain their photometric compliance 
when heated. As stated previously, it is preferable for the agency to 
adopt industry standards whenever it is feasible to do so. 
Additionally, this procedure is presently under consideration for 
incorporation in European standards in Geneva.
    The agency thus proposes to add a new paragraph S5.1.1.24 to read:

    S5.1.1.24 Any lamp whose light is provided by light-emitting 
diodes shall be designed to conform to the photometric requirements 
appropriate for its type when the lamp is stabilized at 
23<plus-minus>5 degrees C, energized, tested 60 seconds after being 
energized, and allowed to operate continuously until either the 
internal heat buildup has stabilized or for 30 minutes, whichever 
occurs first, and tested again.

Optical Combinations

    Standard No. 108 contains requirements for lamps and lamp functions 
which are combined optically. Paragraphs S5.4(b) and (c) refer to 
``combined optically,'' which is defined in SAE J387, ``Terminology--
Motor Vehicle Lighting NOV87.'' This definition states in part that an 
optical combination is a single or two filament light source or two or 
more separated light sources that are operated in different ways. NHTSA 
asks readers for their opinion whether this definition includes LEDs. 
Because LEDs do not have filaments, they are not ``filament light 
sources'' within the meaning of the first part of the definition. 
However, they could be ``two or more separated light sources operated 
in different ways'' within the meaning of the second part of the 
definition. LEDs are sometimes operated at different duty cycles 
depending on the photometric needs of the lamp. For example, because 
the lamps need to be brighter for the stop lamp function, the duty 
cycle would have to be higher than for the taillamp function. NHTSA 
asks whether this would constitute the LEDs being ``two or more 
separated light sources that are operated in different ways'' or is it 
really a single light source operated in different ways? If each LED is 
operated in two or more ways, the definition of ``combined optically'' 
may not be adequate and in need of change to accommodate light sources 
such as LEDs that alone can operate in different ways just by changing 
the nature of the electric signal supplied to them, e.g. different duty 
cycles, a polarity reversal, or alternating current. In this event, 
NHTSA will adopt a revision of the SAE definition and include it in the 
text of Standard No. 108.

Effective Date

    The agency is proposing that S5.1.1.23 and S5.1.1.24 become 
effective one year after issuance of the final rule. However, it does 
not know whether there are existing lamps using LEDs and other 
miniature light sources which would require redesign in order to 
comply. Therefore, based upon the comments, an effective date of later 
than one year is a possibility. Nor does NHTSA know whether there are 
manufacturers who wish to comply with the proposed amendments in 
advance of their effective date. Accordingly, based upon the comments, 
optional compliance with the amendments in advance of their effective 
date is also a possibility.

Request for Comments

    Interested persons are invited to submit comments on the proposal. 
It is requested but not required that 10 copies be submitted.
    All comments must not exceed 15 pages in length (49 CFR 553.21). 
Necessary attachments may be appended to these submissions without 
regard to the 15-page limit. This limitation is intended to encourage 
commenters to detail their primary arguments in a concise fashion.
    If a commenter wishes to submit certain information under a claim 
of confidentiality, three copies of the complete submission, including 
purportedly confidential business information, should be submitted to 
the Chief Counsel, NHTSA, at the street address given above, and seven 
copies from which the purportedly confidential information has been 
deleted should be submitted to the Docket Section. A request for 
confidentiality should be accompanied by a cover letter setting for the 
information specified in the agency's confidential business information 
regulation, 49 CFR part 512.
    All comments received before the close of business on the comment 
closing date indicated above for the proposal will be considered, and 
will be available for examination in the docket at the above address 
both before and after that date. To the extent possible, comments filed 
after the closing date will also be considered. Comments received too 
later for consideration in regard to the final rule will be considered 
as suggestions for further rulemaking action. Comments on the proposal 
will be available to inspection in the docket. NHTSA will continue to 
file relevant information as it becomes available in the docket after 
the closing date and it is recommended that interested persons continue 
to examine the docket for new material.
    Those persons desiring to be notified upon receipt of their 
comments in the rules docket should enclose a self-addressed stamped 
postcard in the envelope with their comments. Upon receiving the 
comments, the docket supervisor will return the postcard by mail.

Rulemaking Analyses

Executive Order 12866 and DOT Regulatory Policies and Procedures

    NHTSA has considered the impact of this rulemaking action under 
Executive Order 12866 and the Department of Transportation's regulatory 
policies and procedures. This rulemaking document was not reviewed by 
the Office of Management and Budget under E.O. 12866, ``Regulatory 
Planning and Review.'' It has been determined that the rulemaking 
action is not significant under Department of Transportation regulatory 
policies and procedures. The effect of the rulemaking action would be 
to adopt terminology more suitable to new technologies. It might 
require minimal redesign of stop lamps, turn signal lamps, and 
taillamps on vehicles in order to substitute LEDs and other miniature 
light sources. However, impacts of the cost of the proposed rule are 
expected to be so minimal as not to warrant preparation of a full 
regulatory evaluation.

Regulatory Flexibility Act

    The agency has also considered the effects of this rulemaking 
action in relation to the Regulatory Flexibility Act (5 U.S.C. Sec. 601 
et seq.). I certify that this rulemaking action would not have a 
significant economic effect upon a substantial number of small 
entities.
    The following is NHTSA's statement providing the factual basis for 
the certification (5 U.S.C. Sec. 605(b)). The proposed amendment would 
primarily affect motor vehicle and lighting equipment manufacturers. 
Under 15 U.S.C. Chapter 14A ``Aid to Small Businesses,'' a small 
business concern is ``one which is independently owned and operated and 
which is not dominant in its field of operation'' (15 U.S.C. Sec. 632). 
Manufacturers of motor vehicles and lighting equipment are generally 
dominant in their fields of

[[Page 34356]]

operations and are not small businesses within the meaning of the 
Regulatory Flexibility Act. Further, small organizations and 
governmental jurisdictions would not be significantly affected by the 
proposed rule as the price of new motor vehicles should not be 
impacted. Accordingly, no Regulatory Flexibility Analysis has been 
prepared.

Executive Order 12612 (Federalism)

    This action has been analyzed in accordance with the principles and 
criteria contained in Executive Order 12612 on ``Federalism.'' It has 
been determined that the rulemaking action does not have sufficient 
federalism implications to warrant the preparation of a Federalism 
Assessment.

National Environmental Policy Act

    NHTSA has analyzed this rulemaking action for purposes of the 
National Environmental Policy Act. The rulemaking action would not have 
a significant effect upon the environment as it does not affect the 
present method of manufacturing motor vehicle lighting equipment.

Civil Justice Reform

    This rule would not have any retroactive effect. Under 49 U.S.C. 
30103(b), whenever a Federal motor vehicle safety standard is in 
effect, a state may not adopt or maintain a safety standard applicable 
to the same aspect of performance which is not identical to the Federal 
standard. Section 30161 sets forth a procedure for judicial review of 
final rules establishing, amending, or revoking Federal motor vehicle 
safety standards. That section does not require submission of a 
petition for reconsideration or other administrative proceedings before 
parties may file suit in court.

List of Subjects in 49 CFR Part 571

    Imports, Motor vehicle safety, Motor vehicles.

PART 571--FEDERAL MOTOR VEHICLE SAFETY STANDARDS

    In consideration of the foregoing, it is proposed that 49 CFR Part 
571 be amended as follows:
    1. The authority section would continue to read as follows:

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


Sec. 571.108  [Amended]

    2. Section 571.108 would be amended by adding paragraphs S5.1.1.23 
and S5.1.1.24 to read as follows:


Sec. 571.108  Standard No. 108; Lamps, reflective devices, and 
associated equipment.

* * * * *
    S5.1.1.23 Instead of being designed to conform to photometric 
requirements based on the number of lighted sections specified in SAE 
J586 FEB84, SAE J588 NOV84, and SAE J585e September 1977, as 
applicable, each stop lamp, turn signal lamp, and taillamp that is 
equipped with light-emitting diodes or other miniature light sources, 
and that needs more than one light source to achieve compliance with 
the photometric performance required of a single lighted section, shall 
be designed to conform to photometric requirements based on the 
dimension of the effective projected luminous lens area for the 
function being tested. A lamp is regarded as having one lighted section 
if the maximum horizontal or vertical linear dimension of the effective 
projected luminous lens area of the lamp is less than 150 millimeters 
(mm), two lighted sections if the dimension is 150-300 mm, and three 
lighted sections if the dimension is greater than 300 mm.
    S5.1.1.24 Any lamp whose light is provided by light-emitting diodes 
shall be designed to conform to the photometric requirements 
appropriate for its type when the lamp is stabilized at 23<plus-minus>5 
degrees C, energized, tested 60 seconds after being energized, and 
allowed to operate continuously until either the internal heat buildup 
has stabilized or for 30 minutes, whichever occurs first, and tested 
again.
* * * * *
    Issued: June 18, 1998.
L. Robert Shelton,
Associate Administrator for Safety Performance Standards.
[FR Doc. 98-16808 Filed 6-23-98; 8:45 am]
BILLING CODE 4910-59-P