Home Page About Us Contribute

Escort, Inc.

Tweets by @CrittendenAuto

By accessing/using The Crittenden Automotive Library/CarsAndRacingStuff.com, you signify your agreement with the Terms of Use on our Legal Information page. Our Privacy Policy is also available there.

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

American Government Special Collections Reference Desk

American Government Topics:  National Highway Traffic Safety Administration, Federal Motor Vehicle Safety Standards

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

Barry Felrice
Federal Register
April 8, 1994

[Federal Register: April 8, 1994]



National Highway Traffic Safety Administration

49 CFR Part 571

[Docket No. 94-23; Notice 1]
RIN 2127-AE97

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

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

ACTION: Notice of proposed rulemaking.


SUMMARY: This notice proposes an amendment to the Federal motor vehicle 
safety standard on lighting that would relieve design restrictions that 
may inadvertently prevent the implementation of certain new-technology 
light sources in signal lamps. These are light emitting diodes (LEDs) 
and miniature halogen bulbs. This action responds in part to a petition 
for rulemaking from Hewlett-Packard, a manufacturer of LEDs. NHTSA also 
seeks comment on performance requirements that would be appropriate for 
long and short arc discharge bulb systems so that Standard No. 108 can 
be amended in a manner that does not inhibit their introduction on 
motor vehicles.

DATES: The comment closing date for the proposal is June 7, 1994. The 
proposed effective date for the final rule is 30 days after its 
publication in the Federal Register. Any request for an extension of 
time to comment must be received not later than 10 days before the 
published expiration date of the comment period.

ADDRESSES: Comments should refer to the docket number and notice 
number, and be submitted to: Docket Section, room 5109, 400 Seventh 
Street, SW., Washington, DC 20590 (Docket hours are from 9:30 a.m. to 4 

FOR FURTHER INFORMATION CONTACT: Richard Van Iderstine, Office of 
Rulemaking (202-366-5280).

SUPPLEMENTARY INFORMATION: The requirements of Federal Motor Vehicle 
Safety Standard No. 108, Lamps, Reflective Devices and Associated 
Equipment, for signal lamps are based upon SAE Standards and 
Recommended Practices that were developed to accommodate incandescent 
bulbs, i.e., those with filaments. Four new technologies have arisen 
that are being or will be used in signal lamps subject to Standard No. 
108. These new signal lamp technologies are light-emitting diodes 
(LEDs), miniature halogen bulbs, long arc discharge bulb systems (e.g., 
neon and other gas filled tubular lamps), and short arc discharge bulb 
systems. It is likely that the latter will be used in headlamps, too. 
In some instances, the specifications of Standard No. 108 have created 
ambiguities and inconsistencies with the design and method of 
performance of the new technologies. NHTSA seeks to resolve these 
through rulemaking that would amend Standard No. 108 to adopt 
equivalent performance specifications for the new light source 
technologies as used in signal lamps and headlamps. This notice is a 
response, also, to a petition for rulemaking to amend Standard No. 108 
in a manner to accommodate LEDs, submitted by Hewlett-Packard 
Corporation. The technologies, associated problems, and suggested 
resolutions are discussed below.

I. LEDs and Miniature Halogen Bulbs

    The advent of the center high mounted stop lamp (CHMSL) in 1985 has 
resulted in some creative solutions of 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 the standard, manufacturers began to resort to smaller 
light sources. For example, the 1986 Chevrolet Corvette used a low 
profile lamp incorporating four miniature halogen bulbs 7.5 mm in 
diameter and 25 mm long. Other CHMSLs have used similar bulbs since. 
LEDs appeared as CHMSL light sources shortly after the first miniature 
halogen bulbs. Typically, a single LED is 6 mm in diameter and less 
than 25 mm long. Because Standard No. 108 contains no light source 
specifications for CHMSLs, LEDs and miniature light sources were 
    However, certain terminology of Standard No. 108 is not entirely 
appropriate for the new technologies. For example, paragraph 
S5.1.1.27(a)(5) still contains the original requirement that the CHMSL 
``shall provide for convenient replacement of the bulb without the use 
of special tools.'' Since an LED is not a ``bulb,'' a more appropriate 
phrase would be ``light source(s)'' as a substitute for ``bulb.'' 
Accordingly, NHTSA is proposing this modification for both 
subparagraphs (a)(5) and (b)(5).
    Manufacturers have been puzzled by the status of LEDs and miniature 
bulbs under Standard No. 108's requirements. Since August 1990, NHTSA 
has provided six interpretations to Hella AG, Stanley Electric Co. 
Ltd., Koito Mfg. Co. Ltd., and Valeo of France. In view of these 
interpretations, NHTSA has concluded that ameliorative rulemaking is 
    In the first of these letters, dated August 22, 1990, NHTSA 
responded to Hella's desire to use miniature bulbs in a lamp that was 
the size of a conventional lamp with one lighted section. Hella asked 
how the requirements for multiple compartment lamps were to be met when 
more than three light sources were provided. Hella appeared to assume 
that Standard No. 108 is to be interpreted in a manner that equates the 
number of lighted sections specified in Figure 1b (one, two, or three 
sections) with the number of bulbs providing the light. NHTSA 
implicitly agreed with Hella's assumption, but ``concluded that any 
device that contains more than three lighted sections need only comply 
with the requirements prescribed for three lighted sections.'' NHTSA 
confirmed this interpretation to Valeo on July 7, 1992.
    On August 29, 1990, NHTSA responded to a request from Stanley for 
an interpretation regarding a lamp with three light sources. Stanley's 
letter seemed to assume that requirements for three lighted sections 
were to be met, but the lamp consisted of a compartment in which all 
three bulbs contributed to the illumination of the lens, without 
interruption by a divider or other light-directing feature. NHTSA 
advised that this was a lamp with a single lighted section, even though 
it contained three light sources.
    Late in 1990, Koito requested an interpretation with respect to 
procedures for photometric measurements of a CHMSL with LEDs. It 
pointed out that LEDs decrease in photometric output after they are 
activated such that after 20 minutes, the output is only slightly more 
than 60 per cent of its original output. On December 17, 1990, NHTSA 
advised that the CHMSL should conform upon each application of the 
brake pedal, regardless of the length of the previous brake application 
and the interval between brake applications. When Stanley reported that 
it would energize a LED CHMSL for 5 minutes before testing, NHTSA 
replied on December 1, 1992, that this was unnecessarily severe.
    In 1993, Stanley asked for an interpretation of a design in which a 
panel of LEDs was flanked by two incandescent bulbs. NHTSA advised on 
April 23, 1993, that the requirements for three lighted sections would 
apply when the panel was operated alone, or in conjunction with one or 
both of the incandescent bulbs.
    NHTSA has also been asked about the appropriateness of following 
for compliance purposes SAE Recommended Practice J1889 JUN88, L.E.D. 
Lighting Devices, now revised as of OCT93. The agency has replied that 
this would be inappropriate because the SAE J1889 is not incorporated 
by reference into Standard No. 108.
    In addition to allowing the use of lamps of smaller size, LEDs 
offer substantial power efficiency over filament lamps, thus reducing 
the amount of wire in the lighting circuits. The major impediment to 
introducing new technology for signal lamps is that Standard No. 108's 
SAE specifications for signal lamps reference SAE Technical Reports. 
Since those Reports are based upon filament-type light sources and the 
expectation that only one light source is needed for a viable lamp, 
they are inappropriate as a basis for requirements for light sources 
such as LEDs and miniature bulbs where many are necessary in a lamp. As 
indicated above in the discussion of past interpretations, the 
performance of a single incandescent bulb can be matched by a cluster 
of LEDs or miniature bulbs. However, the standard appears to equate 
lighted sections of lamps with single light sources. Therefore, in 
designing a signal lamp to use LEDs or miniature light sources which 
typically need more than three each to achieve sufficient intensity, 
the manufacturer must design to the ``three or more'' compartment 
requirement, even though the lamp may be the size of a single bulb 
(compartment) lamp, or even smaller. This can result in a lamp that is 
larger (and more costly) than is necessary for safety.
    SAE J1889 addresses this problem. Paragraph notes that LED 
arrays ``typically cannot be defined in terms of lighted sections like 
those in incandescent lighting devices with multiple bulb 
compartments.'' What SAE J1889 does is to divide the LED-equipped lamp 
into equivalent lighted sections in terms of its maximum projected 
linear dimension. A dimension of 150 mm or less becomes the equivalent 
of a single lighted section, 151 mm to 300 mm, the equivalent of two, 
and anything greater than 300 mm, the equivalent of three. There 
appears to be no technical reason why this concept cannot be applied to 
miniature halogen bulbs as well. Thus, NHTSA's adoption of the SAE 
specification would appear to relieve an unintended design restriction.
    While NHTSA was deliberating this matter, Hewlett-Packard, a 
manufacturer of LEDs, petitioned the agency for rulemaking to amend 
Standard No. 108 in a manner that would accommodate LEDs but in a 
substantially different way than the SAE. The petition argued that 
section of SAE J1889 is far too limiting from standpoints of 
cost and styling. Under this section, LED-equipped lighting devices are 
considered to have more than one lighted section if either the maximum 
horizontal or vertical lighted linear dimensions exceeds 150 mm. 
Instead, Hewlett-Packard would adopt exceptions to the SAE 
specifications incorporated by reference in Standard No. 108 for signal 
lamps that use LED light sources. New language would clarify multiple 
compartment specifications for LED-equipped lamps. With respect to the 
number of lighted sections in such lamps, the petition suggested the 
following language:

    Photometric requirements specified in SAE technical reports 
which are based on the number of lighted sections shall exempt LED 
lighting devices from considerations as multiple compartment lamps 
because of the number of light sources employed in the design. 
Instead, all LED lighting devices shall meet the intensity 
specifications for single compartment lamps provided: (a) The LED 
lamp is designed such that the maximum horizontal or vertical 
distance between the apparent optical centers of the closest 
adjacent LEDs within a lighted section of the lamp is no greater 
than 2.0 cm, (b) if there is more than one lighted section, there 
shall be no more than 2.0 cm from the edge of the closest adjacent 
lighted sections.

    Hewlett-Packard's rationale for this language was:

    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 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 to FMVSS 571.108 will 
guarantee that at least a minimum level of brightness, or sterance, 
will be maintained regardless of the length, area, or shape of the 
lighting device. This will allow lighting designers to fully realize 
all of 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.

    NHTSA believes that a responsive amendment to Standard No. 108 must 
take into consideration the views of both SAE J1889 and Hewlett-
Packard, whether the amendment be based on either, or both, or some 
third way. Therefore, the agency invites comment on the appropriateness 
of the SAE and Hewlett-Packard viewpoints for resolving the apparent 
design restrictions as they relate to LEDs and other miniature light 
    As noted also in the interpretations, the luminous flux of LED 
light sources, unlike filament light sources, drops rapidly as their 
temperature increases. NHTSA stated that photometric conformance should 
be judged immediately upon application of the LED signal lamp. Left 
unstated, but implied, is that conformance should be demonstrated at 
any temperature in the motoring environment.
    Paragraphs and of SAE J1889, respectively, state a 
temperature condition for testing to photometric maxima and minima. For 
measurements to the maximum requirements, the test device, unenergized, 
is stabilized at the laboratory's ambient temperature, 23+/5 degrees C. 
It is then energized and the maximum values within 60 seconds of the 
initial ``on'' time are recorded. For measurements to the minimum 
requirements, the device is also stabilized within the same temperature 
range but in an energized condition until either heat buildup 
saturation has occurred, or 30 minutes has elapsed, whichever first 
occurs. Measurements are then taken of the already energized lamp. 
Although this demonstration procedure is clear, it does not replicate 
the environment in which real lamps must produce correct signals for 
the transmission of safety information. However, it may be the only 
practicable demonstration procedure given the characteristics in use of 
LEDs. The question for NHTSA is whether it should adopt a procedure 
that does not directly correlate to the real world use of a lamp with 
    NHTSA has decided not to propose the adoption of paragraphs 
and in the hope that industry will adopt a more representative 
procedure. Arguably, the point in time at which it is most important 
that a signal lamp convey its message is upon its activation. Further, 
NHTSA believes that activation of a stop signal is likely to be 
momentary in nature, that is to say, less than a minute per brake 
application, and that of a turn signal, less than two minutes. NHTSA is 
concerned, however, about the effect of photometric degradation upon 
hazard warning signals and other signal lamps that remain energized for 
long periods. Hazard warning lamps are frequently operated for extended 
periods of time, some State laws requiring their use to indicate 
vehicles moving at speeds less than 40 mph. Of course, they are used to 
indicate as well the presence of a vehicle which may have been disabled 
in the roadway or adjacent to it. NHTSA has tentatively concluded that, 
until there is further rulemaking on the subject, LED-equipped lamps 
(other than those used for hazard warning signals) and those required 
to be energized during headlamp use are to be tested for photometrics 
in the same manner as conventional ones, that is to say, at ambient 
laboratory temperature and upon activation of the signal. With respect 
to LEDs used to provide the hazard warning signal, NHTSA is following 
the procedure of J1889 and proposing that such lamps meet photometric 
requirements of the SAE standards on turn signals that are incorporated 
by reference in Standard No. 108 when the lamp is stabilized at 23+/-5 
degrees C and allowed to operate continuously until either the internal 
heat buildup has stabilized or for 30 minutes, whichever occurs first.

II. Long and Short Arc Discharge Systems

    Long and short arc discharge light sources will soon become part of 
the design of future lighting systems. Long arc light sources, such as 
neon tubes, appear to be intended for signal lamp use, initially as a 
CHMSL that will surround the rear window glazing or be within it. These 
sources are permitted because Standard No. 108 does not specify 
requirements for signal light sources. Short arc light sources will be 
used initially in headlamp systems, and NHTSA anticipates their 
eventual use in signal lamps.
    Arc light sources do not operate at voltages specified in Standard 
No. 108 for compliance testing, those normally found on contemporary 
vehicles. This incompatibility with Standard No. 108 must be resolved 
before arc light sources are introduced on motor vehicles.
    Specifically, long arcs operate at a hundred volts or more, 
depending on the arc length and the gas employed. For battery-powered 
lamps, such as those on motor vehicles, this means that the lamps must 
have electronic ballasts that provide electric power in accordance with 
the needs of the lamp. There is no standardized manner in which to test 
the light sources, absent the ballasts. Thus, to establish a compliance 
test for lamps using long arcs will be difficult, if not impossible.
    Some time ago, NHTSA amended Standard No. 108 to adopt 
specifications for integral beam headlamps. Short arcs (including their 
ballast systems) are permissible non-replaceable light sources for this 
type of headlighting system. For short arc lamps, the light source, and 
its necessary electronic ballast and high voltage wiring are an 
integral part of the headlamp assembly, and the lamp can be tested for 
photometrics at the 12.8 volts specified by the Standard. However, this 
is the only part of Standard No. 108 that has been developed and 
promulgated with short arc-type lighting in mind. To allow short arcs 
for other lamp applications, NHTSA believes that industry must codify 
interchangeability taking into account the desire of the industry to 
have replaceable ballasts. The SAE appears to be close to beginning 
this effort, as it is nearing completion of a Recommended Practice for 
use of short arc light sources on motor vehicles.
    With the thought of developing appropriate amendments to Standard 
No. 108 to facilitate the introduction of long and short arc discharge 
technology, NHTSA would like to have comments on the following:
    A. Identification of the performance requirements and/or test 
procedures specified, or incorporated by reference, in Standard No. 108 
that should be modified to accommodate the installation of arc 
discharge light sources in lamps required by the standard.
    B. Specification of the performance requirements and/or test 
procedures that should be added to Standard No. 108 to accommodate the 
installation of arc discharge light sources while maintaining the 
present level of safety achieved by incandescent filament light 
    C. Identification of any special considerations that should be made 
to accommodate the concept of a single light source whose light is 
distributed to the vehicle's lamps by lamp pipes, and an opinion as to 
whether it is premature to consider regulation of this concept.
    D. An opinion of when Standard No. 108 should be amended to 
accommodate the use of arc light sources in production motor vehicles.

Proposed Effective Date

    Because the proposed amendments would not impose any additional 
burden and are intended to clarify application of existing 
requirements, it is hereby tentatively found that an effective date 
earlier than 180 days after issuance of the final rule would be in the 
public interest. The final rule would be effective 30 days after its 
publication in the Federal Register.

Rulemaking Analyses

Executive Order 12866 and DOT Regulatory Policies and Procedures

    The Office of Management and Budget has informed NHTSA that it will 
not review this rulemaking action under Executive Order 12866. 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, and would not impose any additional 
burden upon any person. Impacts of the proposal would, therefore, 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. I certify that 
this rulemaking action would not have a significant economic effect 
upon a substantial number of small entities. Motor vehicle and lighting 
equipment manufacturers are generally not small businesses within the 
meaning of the Regulatory Flexibility Act. Further, small organizations 
and governmental jurisdictions would not be significantly affected 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 

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 proposed rule would not have any retroactive effect. Under 
section 103(d) of the National Traffic and Motor Vehicle Safety Act (15 
U.S.C. 1392(d)), 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 105 of the Act (15 U.S.C. 1394) 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.


    Interested persons are invited to submit comments on the proposal 
and questions presented. 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 forth 
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 
late for consideration in regard to the final rule will be considered 
as suggestions for further rulemaking action. Comments on the proposal 
will be available for 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.

List of Subjects in 49 CFR Part 571

    Imports, Motor vehicle safety, Motor vehicles.


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

    Authority: 15 U.S.C. 1392, 1401, 1403, 1407; delegation of 
authority at 49 CFR 1.50.

    2. Section 571.108 would be amended by revising paragraphs 
S5.1.1.27(a)(5) and S5.1.1.27(b)(5), and by adding paragraphs S5.1.1.33 
and S5.1.1.34 to read as follows:

Sec. 571.108  Motor Vehicle Safety Standard No. 108 Lamps, Reflective 
Devices, and Associated Equipment.

* * * * *
    S5.1.1.27(a) * * *
    (5) Shall provide for convenient replacement of the light source(s) 
without special tools.
* * * * *
    (b) * * *
    (5) Shall provide for convenient replacement of the light source(s) 
without special tools.
* * * * *
    S5.1.1.33  Instead of being designed to conform to photometric 
requirements based on the number of lighted sections (compartments), 
each stop lamp and turn signal lamp that is equipped with light-
emitting diodes or other miniature light sources where more than one 
light source is necessary for achieving photometric compliance shall be 
designed to conform to photometric requirements based on the dimension 
of the function of the lamp that is tested. The equivalent of one 
lighted section is a maximum horizontal or vertical linear dimension of 
the effective projected luminous lens area that is less than 150 mm; of 
two lighted sections, 150 mm-300 mm; and of three lighted sections, 
more than 300 mm.


    S5.1.1.33  Instead of being designed to conform to photometric 
requirements based on the number of lighted sections (compartments), 
each stop lamp and turn signal lamp that is equipped with light-
emitting diodes or other miniature light sources where more than one 
light source is necessary for achieving photometric compliance with 
this standard shall be considered to be a single compartment provided 
that the lamp is designed such that the maximum horizontal or vertical 
distance between the apparent optical centers of the closest adjacent 
light sources within a lighted section of the lamp is not greater than 
2.0 cm, and that if there is more than one lighted section, there shall 
be not more than 2.0 cm between the edge of the closest adjacent 
lighted section and the apparent optical center.
* * * * *
    S5.1.1.34  Each lamp that provides a hazard warning signal, and, if 
equipped with light-emitting diodes, each tail, license plate, side 
marker, backup, identification, clearance, and parking lamp, shall be 
designed to conform to the photometric requirements appropriate for its 
type when the lamp is stabilized at 23+/-5 degrees C and allowed to 
operate continuously until either the internal heat buildup has 
stabilized or for 30 minutes, whichever occurs first.

    Issued on: April 4, 1994.
Barry Felrice,
Associate Administrator for Rulemaking.
[FR Doc. 94-8347 Filed 4-7-94; 8:45 am]

Connect with The Crittenden Automotive Library

The Crittenden Automotive Library on Facebook The Crittenden Automotive Library on Instagram The Crittenden Automotive Library at The Internet Archive The Crittenden Automotive Library on Pinterest The Crittenden Automotive Library on Twitter The Crittenden Automotive Library on Tumblr

The Crittenden Automotive Library

Home Page    About Us    Contribute