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

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

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

235 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 235

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