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[Federal Register Volume 89, Number 249 (Monday, December 30, 2024)]
[Rules and Regulations]
[Pages 106365-106374]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2024-31141]

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DEPARTMENT OF TRANSPORTANTION

National Highway Traffic Safety Administration

49 CFR Part 571

[[Docket No. NHTSA-2022-0013]

Federal Motor Vehicle Safety Standards; Lamps, Reflective 
Devices, and Associated Equipment, Adaptive Driving Beam Headlamps

AGENCY: National Highway Traffic Safety Administration (NHTSA or the 
Agency), Department of Transportation (DOT).

ACTION: Denial of petitions for reconsideration.

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SUMMARY: This document responds to the petitions for reconsideration of 
the February 22, 2022, final rule that amended Federal Motor Vehicle 
Safety Standard (FMVSS) No. 108, ``Lamps, reflective devices, and 
associated equipment,'' to enable certification of adaptive driving 
beam (ADB) headlighting systems on vehicles sold in the United States. 
This document denies all petitions for reconsideration received in 
response to the final rule.

DATES: December 30, 2024.

FOR FURTHER INFORMATION CONTACT: For non-legal issues, you may contact 
Adam Lowery, Office of Crash Avoidance Standards, Telephone: (202) 366-
1810, Email: [email protected]; For legal issues, you may contact 
Evita St. Andre, Office of Chief Counsel, Telephone: (202) 366-2992, 
Email: [email protected]. The mailing address for these officials 
is: The National Highway Traffic Safety Administration, 1200 New Jersey 
Ave. SE, Washington, DC 20590.

SUPPLEMENTARY INFORMATION:

Table of Contents

I. Background
    A. Notice of Proposed Rulemaking
    B. Final Rule
II. Petitions for Reconsideration
    A. Stimulus Headlamps Aiming
    B. Allow Representative Vehicles as Stimulus for Compliance 
Testing
    C. ADB System Component-Level Photometric Requirements
    D. ADB Photometry Requirements
    E. Transition Zone
    F. Other
III. Petition of Reconsideration That is Out of Scope
IV. Clarification
V. Conclusion

I. Background

    Beam switching technology was first introduced into vehicles sold 
in the United States in the 1950s and was limited simply to switching 
between upper and lower beams. An adaptive driving beam (ADB) is an 
advanced type of semiautomatic headlamp beam switching technology. It 
uses advanced sensing and computing technology to identify oncoming and 
preceding traffic and actively adapt the beam pattern to limit at lower 
beam levels any light shining toward those vehicles while continuing to 
direct high intensity light to other areas of the roadway. This dynamic 
beam pattern was not previously permitted by NHTSA's lighting standard. 
As such, in 2013, Toyota petitioned NHTSA to modify the standard to 
permit ADB headlighting systems.

A. Notice of Proposed Rulemaking

    NHTSA published a Notice of Proposed Rulemaking (NPRM) on October 
12, 2018, proposing to amend NHTSA's lighting standard, FMVSS No. 108, 
``Lamps, reflective devices, and associated equipment,'' in response to 
a petition that raised concerns that the standard's beam pattern 
(photometry) requirements would not permit the enhanced beam that ADB 
headlighting systems provide.\1\ ADB headlamp technology dynamically 
modifies headlamp photometry to provide more illumination in certain 
areas in and around the roadway while reducing glare towards oncoming 
and preceding motorists. This dynamism is facilitated by the headlamps 
changing the lower beam pattern and increasing the usage of the upper 
beam, the effect of which

[[Page 106366]]

increases visibility, thereby improving safety. NHTSA assessed comments 
received in response to the NPRM and published a final rule on February 
22, 2022.
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    \1\ 83 FR 51766, (Oct. 12, 2018).
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B. Final Rule

    On February 22, 2022, NHTSA published a final rule amending FMVSS 
No. 108, ``Lamps, reflective devices, and associated equipment, 
adaptive driving beam headlamps,'' to enable the certification of ADB 
headlighting systems on vehicles sold in the United States.\2\ Several 
industry comments to the NPRM advocated for stronger harmonization with 
regulatory alternatives when specifying performance requirements for 
ADB systems on vehicles. These alternatives included the regulation 
issued by the Economic Commission for Europe (UNECE R123), the Society 
of Automotive Engineers (SAE) J3069 JUN2016, Surface Vehicle 
Recommended Practice; Adaptive Driving Beam standard, as well as the 
updated version of the SAE Practice published in March 2021. In 
addition, NHTSA conducted laboratory testing to establish appropriate 
performance allowances for ADB systems, driving scenarios, and any 
associated equipment. All information and feedback was reflected in the 
development of the final rule.
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    \2\ 87 FR 9916, (Feb. 22, 2022).
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    FMVSS No. 108 has two main components that ensure ADB systems 
operate safely: (1) vehicle-level track-test requirements specifically 
tailored to the performance of the ADB system in meeting the specified 
glare limits, and (2) component-level photometric requirements related 
to glare and visibility. This standard provides practicable, 
performance-based requirements and test procedures that appropriately 
balance visibility and glare. If vehicle manufacturers choose to equip 
their vehicles with ADB systems, manufacturers must certify that their 
ADB systems meet these requirements.

II. Petitions for Reconsideration

    In response to the February 22, 2022, Final Rule, NHTSA received 
twelve timely petitions from automotive manufacturers, lighting 
suppliers, trade organizations, and the Insurance Institute for Highway 
Safety (IIHS). American Honda Motor Co., Inc. (Honda),\3\ Volkswagen 
Group of America (Volkswagen),\4\ Toyota Motor North America, Inc. 
(Toyota),\5\ Ford Motor Company (Ford),\6\ Koito Manufacturing Co. LTD 
(Koito),\7\ Stanley Electric Co. LTD (Stanley),\8\ North American 
Lighting (NAL),\9\ Valeo Lighting Systems (Valeo),\10\ Alliance for 
Automotive Innovation (Alliance),\11\ the Transportation Safety 
Equipment Institute (TSEI),\12\ SAE International--Lighting Systems 
Group (SAE),\13\ and IIHS \14\ submitted petitions for reconsideration 
of the final rule. Several petitioners requested alignment with 
alternative ADB regulatory practices (i.e., SAE J3069) currently in 
place for systems on vehicles in foreign markets. Many of the petitions 
requested that NHTSA amend the standard to further advance the goal of 
the final rule.
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    \3\ American Honda Motor Co., Inc., Docket No.2022-0013-0011.
    \4\ Volkswagen Group of America, Docket No.2022-0013-0012.
    \5\ Toyota Motor North American, Inc., Docket No.2022-0013-0015.
    \6\ Ford Motor Company, Docket No.2022-0013-0016.
    \7\ Koito Manufacturing Co. LTD, Docket No.2022-0013-0007.
    \8\ Stanley Electric Co. LTD, Docket No.2022-0013-0008.
    \9\ North American Lighting, Docket No.2022-0013-0009.
    \10\ Valeo Lighting Systems, Docket No.2022-0013-0010.
    \11\ Alliance for Automotive Innovation, Docket No.2022-0013-
0013.
    \12\ Transportation Safety Equipment Institute, Docket No.2022-
0013-0014.
    \13\ SAE International--Lighting Systems Group, Docket No.2022-
0013-0005.
    \14\ Insurance Institute of Highway Safety--Highway Loss Data 
Institute, Docket No.2022-0013-0017.
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    The topics raised in the petitions can be generally classified into 
one of the following categories: (1) requests to address perceived 
complexities in technical scenarios; (2) claims that NHTSA imposed 
conflicting substantive requirements for testing; (3) requests to add 
alternative ADB headlamp testing procedures; and (4) requests to amend 
technical areas of the final rule to clarify requirements. This 
document addresses the petitioners' concerns.

A. Stimulus Headlamps Aiming

    FMVSS No. 108 specifies three specific headlamps and rear 
combination lamps mounted on test fixtures as part of the track testing 
for ADB systems. Additionally, FMVSS No. 108 requires that all 
headlamps must be aimable. As such, the stimulus lamps specified in the 
ADB track test procedure, used to elicit ADB performance, are capable 
of being aimed. However, while the Final Rule stated that the stimulus 
headlamps will have the lower beam activated and aimed per the SAE 
Recommended Practice J599 Lighting Inspection Code (SAE J599) 
procedures, these SAEJ599 aiming instructions were not included and 
incorporated by reference in the regulatory text.\15\ Toyota stated 
that, to ensure repeatability of testing, NHTSA should specify how the 
stimulus headlamps on the ADB test fixture will be aimed, as the 
regulatory text from the final rule does not include stimulus headlamp 
aiming instructions. Toyota suggested the headlamps be aimed in 
accordance with manufacturer instructions, or alternatively, in 
accordance with SAE J599. However, regarding SAE J599, Toyota stated 
that this procedure could introduce more variation and potentially 
stray away from real-world representation of the stimulus devices. The 
Alliance also petitioned that NHTSA provide in the docket the 
manufacturer's headlamp aiming instructions and information sufficient 
to mount the stimulus lamps specified in the FMVSS No. 108.
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    \15\ See 87 FR 9947 (Feb. 22, 2022) (``The final rule also 
clarifies various aspects of the test procedures related to the 
fixture lamps. It clarifies that the stimulus headlamps will have 
the lower beam activated and aimed per the SAE Recommended Practice 
J599 Lighting Inspection Code (J599) procedures, as applicable.'').
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Agency Response
    NHTSA is denying the request to incorporate into the regulatory 
text aiming instructions for the stimulus headlamps installed on the 
ADB test fixtures. As clarified in the final rule, NHTSA will aim the 
stimulus headlamps as a matter of good testing practice; however, it is 
not necessary to include such a condition as part of the regulation 
because headlamp aim on the stimulus test fixtures does not have enough 
variability to change the outcome of the ADB test. As detailed in the 
discussions of the SAE J3069 synthetic light source in the NPRM and 
final rule, the minimum taillamp intensities for which an ADB system is 
required to react are considerably lower than a headlamp's intensity. 
Even at the extremes of headlamp aim, a headlamp will always emit more 
light than a taillamp and the ADB recognition system must be capable of 
detecting intensities as low as those of taillamps. Therefore, stimulus 
headlamp aim will not be a deterministic factor in the outcome of an 
ADB test.\16\
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    \16\ 87 FR 9947 (Feb. 22, 2022) (``As NHTSA explained in the 
NPRM, the minimum taillamp intensities allowed by FMVSS No. 108 (2.0 
cd at H-V and as low as 0.3 cd at 20 degrees) are considerably lower 
than the 7.0 cd lamp specified in SAE J3069 NHTSA also does not 
agree with SAE that specifying actual vehicle headlamps would result 
in excessive variability, but continues to believe, as stated in the 
NPRM, that gradients in typical headlamp beam patterns would likely 
only affect the repeatability of the test if the reaction by the ADB 
system changes based on this difference. If this is the case, the 
ADB system will have this issue in actual use (especially since the 
specified headlamps are from high-selling vehicles and therefore 
common on the road), and this should not be considered variability 
attributable to the test, but a failing of the ADB system. In any 
case, NHTSA's testing showed that the tested ADB system was 
generally able to recognize the fixtures fitted with these 
lamps.'').

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[[Page 106367]]

    Further, including specific headlamp aiming instructions for the 
stimulus test fixtures would overly prescribe the test conditions, 
encouraging manufacturers to design narrowly to the test instead of 
real-world safety needs. The required testing is meant to be 
representative of on-the-road situations where ADB systems should react 
regardless of the precise aim of the stimulus headlamps. On the road, 
the headlamps installed on surrounding traffic are not likely to be 
perfectly level due to variations such as the slope of the roadway and 
may even be misaimed, presenting ADB systems with headlamp gradient 
locations that are not predictable. While an ADB system might use 
headlamp gradients as an optional method to assist in distinguishing 
vehicles from other light sources such as streetlights, misaim of 
stimulus headlamps should not preclude the ADB system from recognizing 
the need to reduce intensity. Thus, ADB systems should not be 
particularly sensitive to the aim of the stimuli headlamps.
    NHTSA is not docketing specific aiming information from the 
manufacturers of the stimulus headlamps. While custom aiming strategies 
may be appropriate for these lamps when mounted on the vehicles on 
which they were originally designed to be installed, any such 
instructions would be inapposite for these lamps when mounted in the 
locations specified for the stimulus test fixtures, as here. For 
instance, the Ford F-150 headlamps are likely mounted higher when 
installed on a pickup truck as compared to the mounting height 
specified for the ADB test fixture. As such, any offset used for these 
lamps while installed on a pickup truck, would be inappropriate for the 
mounting location specified for the test fixture. The manufacturer 
aiming instructions are therefore not fitting in a testing context.
    The Agency disagrees that it is necessary to specify in the 
regulatory text specific aiming instructions for the stimuli headlamps 
(whether those in SAE J599, or otherwise) and denies these petitions.

B. Allow Representative Vehicles as Stimulus for Compliance Testing

    FMVSS No. 108 specifies ADB test fixtures equipped with stimulus 
lamps for use in performing the dynamic ADB performance tests. This 
approach minimizes complexity and harmonizes with SAE J3069 (March 
2021) while ensuring that ADB systems operate safely. While the test 
fixtures' specifications follow SAE J3069 with respect to the locations 
of the photometers \17\ and stimulus lamps, FMVSS No. 108 departs from 
SAE J3069 in that it requires the use of more real-world representative 
lighting in the test procedure by specifying original equipment vehicle 
headlamps and taillamps mounted on test fixtures.\18\
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    \17\ A photometer, or illuminance meter, is an instrument that 
measures light.
    \18\ See 87 FR 9996 (Feb. 22, 2022) Table 15 (Summary of Major 
Differences Between the Final Rule and SAE J3069).
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    In their petitions for reconsideration, Toyota and the Alliance 
stated that NHTSA should allow, as a manufacturer's option, actual 
vehicles in place of ADB test fixtures for use in compliance testing. 
The petitioners suggested that NHTSA modify the final rule by 
specifying the three vehicles identified in the Final Rule to 
accommodate more advanced ADB systems.\19\
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    \19\ MY2018 Toyota Camry, Ford F-150, Harley Davidson Sportster.
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    Toyota and the Alliance stated that representative vehicles would 
permit ADB sensor arrays (e.g., camera- or radar-based systems) to 
properly account for the characteristics of real-world oncoming and 
preceding vehicle scenarios, complementing vehicle lighting detection 
methodologies that current ADB systems use. The Alliance stated that 
more realistic real-world conditions would differentiate between other 
light sources in the environment that might impact detection. Toyota 
stated that the ADB-equipped Lexus NX used by NHTSA for internal 
research was an older generation system and that other, more advanced 
ADB systems, with additional advanced sensing, can rely on (other) 
vehicle characteristics to enhance object recognition to more 
accurately determine how to adjust the headlamp beam pattern. The 
petitioners stated that allowing representative vehicles as stimulus 
for compliance testing would be safety-beneficial and enhance system 
performance.
Agency Response
    NHTSA is denying the request for the option to use representative 
vehicles in place of stimulus test fixtures to demonstrate compliance 
for ADB systems during track testing.
    The NPRM initially proposed using representative vehicles during 
track testing. However, following review of comments expressing 
significant opposition, NHTSA specified stimulus test fixtures in place 
of vehicles and explained its reasoning for doing so at length in the 
final rule.\20\ FMVSS No. 108 does not preclude the use of potential 
stimulus vehicles to improve ADB systems; thus, NHTSA sees no issue 
with vehicle manufacturers using vehicles to further evaluate the 
performance of their ADB systems. However, performance above and beyond 
what is required by FMVSS No. 108 does not supersede what is required 
in the standard.
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    \20\ Among other reasons, NHTSA concluded that using real 
vehicles would generally not challenge ADB systems any more robustly 
than the test fixtures fitted with original manufacturer replacement 
equipment vehicle headlamps and taillamps, as specified in the final 
rule. Testing showed that the ADB system detected and responded to 
the finalized test fixtures in generally the same way it did to an 
actual vehicle. See 87 FR 9934 (Feb. 22, 2022). This obviated the 
need to include vehicle testing as an option.
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    By requiring the use of original equipment headlamps and taillamps 
on the ADB test fixtures, FMVSS No. 108 establishes a minimum 
performance standard that all motor vehicles with ADB headlighting 
systems are required to meet. Other vehicle characteristics may not be 
universal components or present in all vehicles. For example, grilles 
are a characteristic on certain vehicles, but are not a required 
component like headlamps and thus not present on some electric 
vehicles. Rather, FMVSS No. 108 as finalized reflects that lighting is 
the central object of detection for ADB sensors.
    Because the regulatory text specifies how NHTSA will evaluate FMVSS 
No. 108 compliance for ADB systems and the requirements for ADB do not 
inhibit manufacturers' use of representative vehicles for ADB 
development, NHTSA denies the petitions from Toyota and the Alliance to 
allow representative vehicles as a stimulus in compliance testing.

C. ADB System Component-Level Photometric Requirements

    In FMVSS No. 108, the component-level photometric requirements, 
among other things, ensure that the ADB system provides a minimum level 
of visibility while limiting the maximum level of glare it may direct 
toward other drivers. The vehicle-level ADB test procedure evaluates 
the degree of glare that an ADB system casts on the ADB stimulus test 
fixture in specific scenarios; it does not evaluate visibility. 
Accordingly, FMVSS No. 108 applies the existing component-level 
photometric intensity requirements to portions of the adaptive driving 
beam. The adaptive driving beams must

[[Page 106368]]

consist only of area(s) of reduced intensity, area(s) of unreduced 
intensity, and transition zone(s). ADB systems are subject to several 
requirements that are measured in a laboratory, including that it must 
be designed to conform to the Table XIX (lower beam photometry) 
requirements in an area of reduced intensity, and that it must be 
designed to conform to the Table XVIII (upper beam photometry) 
requirements in an area of unreduced intensity.
    Stanley stated that replicating the conditions of an actual vehicle 
test within a laboratory setting, to conduct a photometric test with 
headlamps, is ``almost impossible.'' Stanley stated that future ADB 
(micro) LED headlamps could necessitate testing an infinite combination 
of areas of reduced intensity. Stanley petitioned NHTSA to only use 
vehicle-level testing for ADB systems verification and use component-
level testing to confirm the lower beam limits with the reduced 
intensity area turned off, and upper beam limits with the area of 
unreduced intensity turned on for vehicle headlamps as they would 
without the ADB. NAL and Koito's petitions suggested similar 
approaches, with Koito suggesting that ADB component-level photometry 
requirements be changed to the minimum and maximum lower-beam values in 
the area of reduced intensity, and the minimum lower-beam values and 
maximum upper-beam values in the area of unreduced intensity.
    Valeo and TSEI petitioned for NHTSA to create a series of specific 
standardized laboratory compliance tests for ADB systems. According to 
the petitioners, the lack of a defined test method could lead to an 
unreasonable, if not an impracticable, amount of time employing various 
possible implementations of ADB systems spanning a vast range of 
changing scenarios. TSEI suggested adopting a specific set of test 
points/lines/zones corresponding to the test scenarios of Table XXII 
and glare levels of Table XXI.
    Valeo's petition acknowledged that the preamble of the final rule 
states that all possible ADB headlamp configurations would not 
necessarily need to be tested but suggested that the suppliers need 
data from actual testing or simulations that show all possible ADB 
configurations satisfy the lighting standard. Valeo requested that 
NHTSA devise a specific test plan with eleven set-ups that would cover 
most, if not all, of the possible set-ups to ensure manufacturers can 
certify compliance for the FMVSS No. 108 requirements.\21\ Both TSEI 
and Valeo requested that NHTSA adopt vehicle track test scenarios 
comparable to UNECE regulations.
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    \21\ Valeo's petition shows several laboratory testing set-ups 
for the different ADB road test scenarios and different photometers 
distances. See Docket No. 2022-0013-0010, Figures 8 to 12 (Figure 8 
shows testing at 15 m and testing distance is increased in each 
figure up to 220 m in Figure 12).
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Agency Response
    NHTSA is denying the petitioners' request to modify the component-
level photometric intensity requirements. The purpose of component-
level photometric requirements is to complement the dynamic vehicle 
track testing and ensure that the ADB system always provides the driver 
with a minimum level of visibility. The track tested requirements 
encompass many common scenarios (e.g., a single oncoming vehicle in the 
adjacent lane) while evaluating ADB system glare, but they do not test 
glare in every conceivable driving scenario, nor do they evaluate 
visibility. For example, an area of unreduced intensity that is 
exceedingly bright (e.g., exceeds the 75,000 cd upper beam maximum) 
could create glare beyond the maximum track tested distance of 220 m. 
Component-level photometric requirements therefore must help serve as a 
backstop to the track test by ensuring that areas of unreduced 
intensity are not exceedingly bright out to this distance and glare to 
other vehicles is minimized.
    The component-level photometric requirements generally ensure 
adequate visibility by specifying minimum levels of light at certain 
locations (test points) that correspond to different locations on the 
road. Manufacturers are provided broad flexibility in determining which 
areas of the roadway receive an area of reduced intensity or an area of 
unreduced intensity. The component-level requirements ensure that any 
areas of reduced intensity (up to and including a pattern equivalent to 
a full lower beam) do not exceed the Table XIX (lower beam) maxima, and 
any areas of unreduced intensity (up to and including a pattern 
equivalent to a full upper beam), do not exceed the Table XVIII (upper 
beam) maxima. Conversely, these component-level requirements ensure 
adequate illumination by ensuring that the minima in Tables XVIII and 
XIX are also met.
    While NHTSA will verify compliance to Table XIX (lower beam 
photometry requirements) and to Table XVIII (upper beam photometry 
requirements) through headlamp testing, manufacturers have the 
flexibility to certify compliance to the component-level photometric 
requirements based on other means. As an initial matter, the complexity 
of certification is based on the complexity of a manufacturer's 
adaptive beam. If a manufacturer chooses to create a simple adaptive 
beam, that beam will be less complex to certify than a beam that has 
multiple areas of reduced intensity or a beam that moves the areas of 
intensities. In this way, manufacturers may, in their discretion, limit 
the number of combinations as needed to create a system that they can 
properly certify. Certification to the component-level requirements may 
also be accomplished by actual testing, simulation or any valid means 
that demonstrate that the requirements are met and that ensure that if 
NTHSA tests the lamps they will meet the requirements.
    Additionally, the component level requirements are consistent with 
longstanding categorization methods used for headlamp beam patterns 
because they use intensity values at various horizontal and vertical 
angles. This longstanding method is already used by manufacturers 
throughout the design and validation process when developing headlamps. 
As such, manufacturers are likely already aware of the ADB patterns 
which they have designed for particular purposes.
    In considering the petitions to create a series of specific 
standardized laboratory compliance tests for ADB systems, NHTSA does 
not wish to limit the flexibilities currently provided to manufacturers 
to create dynamic beam patterns. If a manufacturer wishes to limit the 
number of patterns produced by its ADB system to decrease the 
measurements required to certify their system, it may do so. Likewise, 
if a manufacturer wishes to create a dynamic beam pattern that includes 
many combinations of reduced and unreduced areas, the requirements also 
offer that flexibility. Regardless of the component-level evaluation 
through actual testing or simulation, the manufacturer must certify 
that whatever beam pattern its ADB headlamp produces has only areas of 
reduced, unreduced, and transition zones. In taking this approach, 
NHTSA has maximized the manufacturers' flexibility to create beam 
patterns that satisfy their customers, while also protecting other road 
users from glare. NHTSA therefore denies these petitions.

D. ADB Photometry Requirements

    Areas of reduced intensity must meet the component-level 
photometric

[[Page 106369]]

requirements for a lower beam.\22\ In addition to the component-level 
photometric requirements, vehicles using ADB headlighting systems are 
required to maintain these standards while performing dynamic testing 
on a track. As a part of the track testing, FMVSS No. 108 specifies the 
use of ADB test fixtures, which each contain stimulus lamps and 
photometry sensors.\23\ For an ADB headlamp, FMVSS No. 108 states the 
headlighting system must meet the photometry requirements of Table XXI 
(Adaptive Driving Beam Photometry Requirements) which sets the maximum 
illuminance within marked measurement distance intervals within a 220 m 
range.\24\
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    \22\ For instance, in accordance with Table XIX, headlamps 
observed at test point 0.5U, 1R-3R (deg) must abide by a minimum 
photometric intensity of 500 cd and maximum photometric intensity of 
2700 cd.
    \23\ 49 CFR 571.108 S14.9.3.12.3.1.
    \24\ See 49 CFR 571.108 S14.9.3.12.2. and 49 CFR 571.108, Table 
XVIII (Headlamp Upper Beam Photometry Requirements), Table XXI 
(Adaptive Driving Beam Photometry Requirements). As an example: at 
distances less than 30 m and greater than or equal to 15 m, the 
maximum illuminance for an oncoming vehicle is 3.1 lux and the 
maximum illuminance for a same direction vehicle is 18.9 lux.
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    Several petitioners \25\ asserted that ADB headlighting systems 
cannot concurrently meet the requirements set forth in the component-
level tests and the vehicle-level tests. The petitions stated that the 
maximum permitted illuminance values associated with specific driving 
scenarios (such as right curves, straight-path, etc.) were particularly 
difficult to meet while also maintaining the component-level 
photometric requirements. They suggested, among other actions, that 
vehicles with ADB systems may need to have their headlamps permanently 
aimed downward and/or mounted at specific heights to meet the ADB 
photometry requirements. IIHS asserted that NHTSA's decision to apply 
left side beam pattern glare limits to the ADB headlighting system 
imposed an asymmetry during vehicle-level testing of right curves. IIHS 
stated that the more demanding requirements could only be satisfied 
with more advanced ADB systems.
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    \25\ Specifically SAE, Stanley, Toyota, Ford, TSEI, NAL, IIHS, 
Valeo, Volkswagen, Koito and the Alliance.
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    SAE, Stanley, and Koito each identified photometric test point 
0.5U, 1R-3R as an instance where the ADB maximum allowed illuminance 
values (glare limit) will fall below the headlamp lower beam 
photometric intensity minimum. SAE presented multiple right curve 
calculations to support its claim. The first area in which SAE claimed 
conflicting requirements exist is at the lower beam photometric test 
line of 0.5U, 1R-3R. This particular lower beam photometric scan 
(laboratory) requires a minimum intensity of 500 cd throughout the 
line, while allowing a maximum of 2,700 cd anywhere along the line. 
During right curve ADB test scenarios, the photometer on the test 
fixture will have a relative travel path that will cross this same test 
line at some test distance (the distance varies with factors such as 
curve radius, headlamp mounting height, etc.). SAE stated that the 
dynamic vehicle test also imposes a glare limit on the same region of 
the beam pattern which it claimed does not match the corresponding 
component-level photometry requirement.
    In its petition, SAE presented an example showing a 400 m right 
curve and an ADB headlamp mounting height of 600 mm. In the example, 
the lower beam maximum of 2,700 cd (laboratory) along that line for a 
single headlamp would now be limited to 2,160 cd (track) from the pair 
of ADB headlamps. SAE further stated that dividing this value for each 
of the two headlamps results in approximately 1,080 cd from a single 
ADB headlamp imposed by the vehicle driving test requirements. SAE 
stated that the component-level minimum of 500 cd is also required for 
lower beams along that same photometric scan line. SAE described this 
smaller window of compliance as a conflict, claiming that an intensity 
not much greater than the minimum intensity required along the 0.5U, 
1R-3R line would fail the ADB vehicle testing requirements. SAE also 
presented an example for a 210 m right curve and an ADB lamp mounting 
height of 800 mm where the upper limit would be approximately 1103 cd 
per ADB headlamp (track) along the same 0.5U, 1R-3R line that again has 
a 500 cd minimum.
    SAE also presented an example for an area close to the lower beam 
test point of 2U-4L (Laboratory). SAE stated that this test point 
requires a minimum of 135 cd. SAE further calculated that, for the 210 
m right curve at an ADB mounting height of 600 mm, the lux meter 
position for the vehicle test would be very close to the 2U-4L point at 
15 m distance. The track test maxima require no greater than 700 cd 
from a pair of ADB headlamps, or 350 cd per ADB headlamp, which SAE 
stated allows only a small design window.
    TSEI stated its concurrence with SAE's petition. It further stated 
that the glare and lower beam photometry requirements, along with the 
requirement for a 1-degree transition zone, deviate from the definition 
of ADB systems as an evolution of headlamp beam switching devices where 
specific zones of the upper beam are dimmed, leaving intensity of the 
dimmed zone at a level equal to the lower beam. TSEI stated that unless 
the ADB system is deactivated while performing on right curves, under 
the standard as currently written, the lower beam portion of the ADB 
system would need to be re-aimed downward or dimmed to comply. TSEI 
stated that either of those choices would reduce the performance and 
increase the cost of the system.
    Ford presented a comparison of the performance of compliant 2021 F-
150 headlamps while undertaking right curves, aimed nominally versus 
oriented 3 inches downward, to meet the glare limits of the final 
rule.\26\ Ford's comparison highlighted that the headlamps largely 
exceeded the maximum illuminance requirements defined in Table XXI at 
nominal, while the downwardly aimed headlamps met the requirements. For 
example, for distances less than 60 m and greater than or equal to 30 m 
the maximum illuminance requirement is 1.8 lux, yet the illuminance at 
nominal aim was 4.4 lux and the illuminance when aimed 3 inches down 
was 1.1 lux. In addition, when translated into forward visibility on a 
straight road, Ford determined that the downward aiming decreased the 
forward lower beam seeing distance by 40.3%. For those reasons, Ford 
petitioned for the creation of a separate glare limit for right curves, 
in order to maintain a high level of road visibility for drivers. Ford 
also petitioned based on the IIHS's Headlight Test & Rating Protocol 
\27\ for updates of the illuminance values in Table XXI.\28\
---------------------------------------------------------------------------

    \26\ See Docket No. NHTSA-2022-0013-0016; Appendix A.
    \27\ See Insurance Institute for Highway Safety, Headlight Test 
& Rating Protocol, Ver. III (July 2018), https://www.iihs.org/media/0e823704-32d1-4500-b095-15d064d824a7/ZJciYw/;.(last accessed Dec. 
18, 2024)
    \28\ Ford suggests using the following values in Table XXI: for 
distances less than 30 m and greater than or equal to 15 m, a 
maximum illuminance for right curves of 7.1; for distances less than 
60 m and greater than or equal to 30 m, a maximum illuminance for 
right curves of 4.8; and for distances less than 120 m and greater 
than or equal to 60 m, a maximum illuminance for right curves of 
2.1.
---------------------------------------------------------------------------

    Valeo asserted that currently compliant headlamps that meet 
photometric requirements would not meet the requirements in the 
standard on vehicles with higher mounting heights during same direction 
driving scenarios. Valeo performed an internal investigation with three 
headlamp mounting heights (750 mm, 900 mm,

[[Page 106370]]

and 1160 mm) to evaluate glare compliance for the vehicle rearview 
mirrors and driver's eyes photometers at distances of 15 m, 30 m, 60 m, 
and 120 m. Valeo composed photometric figures (Figures 5-7) on a 
coordinate system that showed the intensity (cd) from the left side 
headlamps of the outside rearview mirrors and driver's eyes photometers 
during the same direction (straight-path) road test.\29\ Figure 5 
showed a 750 mm headlamp mounting height, Figure 6 showed a 900 mm 
mounting height, and Figure 7 showed a 1160 mm mounting height. Each 
figure identified several points of interest, corresponding mirror and 
photometer locations, where Valeo calculated that the photometric 
intensity would exceed the bounds of the lower and upper beam 
photometric requirements, at a given distances, for the specified 
mounting height. As such, Valeo stated that it does not believe that 
redesigning the lower beam photometric output would resolve the issue, 
as recommended in the rule that permitted the installation of ADB 
systems. Instead, Valeo recommended that NHTSA change the glare 
requirements, so that they are calibrated to the headlamp being tested 
instead of it being a fixed value.
---------------------------------------------------------------------------

    \29\ See Docket No. NHTSA-2022-0013-0010, Figures 5-7.
---------------------------------------------------------------------------

    Toyota presented a similar analysis, characterizing the pitch of a 
high-mounted lower beam versus normal aiming.\30\ Toyota determined 
that headlamps positioned at a height of 1.1 m would need to lower 
their vertical aiming angle by 1.41 degrees to meet the photometry 
requirements in the final rule. However, the adjusted vertical aiming 
angle would result in a roughly 120 m reduction in forward visibility 
at 3 lux of lower beam visibility, creating ``sub-optimal visibility'' 
for the driver in the area of reduced intensity.
---------------------------------------------------------------------------

    \30\ See Docket No. NHTSA-2022-0013-0015, Figure 1.
---------------------------------------------------------------------------

    The petitioners suggested that due to perceived conflict enabled by 
the narrow acceptable intensity margin presented in Table XIX (Headlamp 
Lower Beam Photometry Requirements) and XXI (Adaptive Driving Beam 
Photometry Requirements), NHTSA should allow industry stakeholders to 
dim or re-aim the lower beam during right curves. Several petitioners 
requested NHTSA consider aligning with SAE J3069, essentially providing 
the option to evaluate the ADB glare requirement by stipulating the 
illuminance of the ADB either not exceed the values listed in Table XXI 
or not exceed by more than 25% the illuminance produced by the same 
vehicle's lower beam. Ford alternatively petitioned NHTSA to amend 
FMVSS No. 108 to reflect its own petitioned values for Table XXI, 
though Ford stated that it would request that NHTSA provide a phase-in 
period to allow vehicle manufacturers the time to validate the more 
stringent requirements.
Agency Response
    NHTSA is denying the petitioners' requests to modify the track 
limits in Table XXI of FMVSS No. 108 by permitting ADB illuminance to 
exceed the vehicle's lower beam illuminance by up to 25%. NHTSA is also 
denying Ford's petitioned changes to Table XXI (Adaptive Driving Beam 
Photometry Requirements), to create separate standards for right and 
left opposite direction curves. Further modifications to FMVSS No. 108, 
such as those raised by the petitioners, are not necessary because 
options already exist for ADB systems to mitigate glare while adhering 
to the component-level photometric requirements. These flexibilities 
are available to the manufacturer and discussed below.
    NHTSA established photometry requirements for headlamp upper and 
lower beams in Table XVIII and Table XIX of the lighting standard 
(FMVSS No. 108), respectively. NHTSA standardizes vehicle headlamps to 
satisfy two safety needs: visibility and glare prevention. Headlamp 
lower beams are designed to provide relatively high levels of light in 
the close-in forward visibility region, and to provide reduced light 
intensity in longer-distance regions, where oncoming or preceding 
vehicles would be glared. The upper beams are designed to provide 
relatively high levels of illumination in both close-in and longer 
distance regions. For adaptive driving beams, NHTSA designated the 
photometry requirements, specified as a directional maximum illuminance 
per measurement distance interval, on the left or driver side of the 
vehicle. For example, over a measurement distance interval greater than 
or equal to 15.0 m and less than 30.0 m, the maximum illuminance for a 
vehicle in the opposite direction is 3.1 lux; for a vehicle driving in 
the same direction, the maximum illuminance is 18.9 lux.
    NHTSA reiterates that it currently allows vehicle manufacturers the 
option to dynamically re-aim headlamps during driving. Potential issues 
of glare due to headlamp mounting height can be addressed with the on-
vehicle (dynamic) aim of the headlamps. NHTSA has previously explained 
that for headlamp systems capable of dynamically re-aiming the 
headlamps (e.g., based on the steering angle), the laboratory 
photometry requirements ``must be met in the nominal position of the 
lower beam headlamp (i.e., considering the location of the axis of 
reference to coincide with the longitudinal axis of the vehicle).'' 
\31\
---------------------------------------------------------------------------

    \31\ See Letter to Kiminori Hyodo, Koito Manufacturing Co., Ltd. 
(Feb. 10, 2006), https://www.nhtsa.gov/interpretations/hyodob-3 
(last accessed Dec. 18, 2024); see also 68 FR 7101 (Feb. 12, 2003) 
(discussing application of laboratory photometry requirements to 
adaptive frontal-lighting systems).
---------------------------------------------------------------------------

    With respect to the comments about vehicles equipped with high-
mounted headlamps, the issue of glare is also present with respect to 
the lower beams on those vehicles. As such, those vehicles already tend 
to have their headlamps aimed downward to avoid glaring oncoming or 
preceding vehicles. Toyota contended that aiming beams downward would 
reduce seeing distance. However, this concern presumes that a 
manufacturer aims an entire system's beams downward instead of aiming 
the adaptive driving beam only. If a manufacturer aims only the 
adaptive driving beam somewhat lower, that will likely have the 
greatest impact on areas of reduced intensity, not areas of unreduced 
intensity (due to the characteristics of lower beam and upper beam 
patterns). This would not likely have an outsized impact on seeing 
distance as Toyota suggests.
    Additionally, manufacturers have the flexibility to alter the 
vertical arrangement of the headlamps and/or light sources to mitigate 
glare. Vertical arrangement refers to the positioning of each headlamp 
when multiple headlamps are used. FMVSS No. 108 S9.4.1.6.5 expressly 
permits the adaptive driving beam to be provided by any combination of 
headlamps, allowing ADB systems to produce the adaptive driving beam 
out of a headlamp that is mounted lower on the vehicle. This regulatory 
language directly addresses the concerns raised by commenters that 
cited high-mounted headlamps as causing a glare issue. Ford and the 
Alliance acknowledged this option in their comments to the NPRM.\32\
---------------------------------------------------------------------------

    \32\ NHTSA-2018-0090-0162; NHTSA-2018-0090-0138.
---------------------------------------------------------------------------

    SAE, in its petition, calculated that during certain curve 
scenarios the maximum glare limits are less than the maximum allowed 
photometry values. Considering the example that results in the highest 
discrepancy based on the provided calculations (the 400 m right curve 
example), the maximum value at that test point is still more than twice

[[Page 106371]]

the minimum at the same point (1,080 cd from SAE calculations vs the 
500 cd minimum in FMVSS No. 108). A 580 cd (1,080 cd-500 cd) range of 
intensity values is sufficient for the design of a compliant ADB lamp, 
especially considering that the ADB system could dynamically re-aim in 
order to avoid glare during the ADB track tests. As mentioned 
previously, a lamp with an output which may exceed the dynamic track 
test limits for glare could re-aim downward (or use other means) to 
alleviate glare. The Agency retains this requirement, as detailed in 
the final rule, because ADB systems can detect oncoming vehicles and 
adapt accordingly, thus outperforming traditional lower and upper beams 
in reducing glare.\33\ It is therefore appropriate to hold ADB systems 
to a higher standard.
---------------------------------------------------------------------------

    \33\ 87 FR 9957, (February 22, 2022). The agency notes that even 
with this modification, the glare limits in this final rule are 
still (as Stanley suggested) more stringent than currently allowed 
by the Table XIX right-side maxima from 1R to 3R. However, this 
level of stringency is reasonable and provides a manageable design 
range. The lower beam photometry was designed to provide a generic 
beam to prevent glare regardless of the actual road and traffic 
conditions; it was not customized to provide glare protection to 
oncoming vehicles on a right curve. Because most situations in which 
an oncoming vehicle can be glared will occur with the oncoming 
vehicle to the left, the existing Table XIX lower beam photometry 
requirements require shading the left side and permit more light on 
the right side. However, the adaptive driving beam is not, and need 
not be, an all-purpose beam like a conventional lower beam. It is 
clear in the photometry tables that the appropriate glare limits for 
oncoming situations are the left-side maxima in Table XIX, on which 
the oncoming glare limits are based. These limits should, to the 
extent possible, apply to oncoming glare, including from the right-
side. In any case, the agency believes that current lower beams 
would generally comply with the glare limits as applied in this 
scenario with the revised measurement distance range.
---------------------------------------------------------------------------

    In its petition, through an internal analysis, Valeo asserts that 
fully compliant lower beams would fail the glare requirements for same 
direction driving scenarios. However, upon inspection of their 
analysis, NHTSA recognized that Valeo had instead applied the adaptive 
driving beam photometry requirements (Table XXI) for oncoming/opposite 
direction scenarios when grouping the intensity measures for the 
locations of the side-view mirrors and driver photometers, shown in 
figures 5-7. NHTSA also observed that Valeo analyzed test setups using 
headlamp mounting heights that were nearly level with the 1.2 m driver 
photometer, in particular the 1.16 m height. Headlamp setups of that 
stature are unlikely and would glare drivers without proper re-aiming. 
Because Valeo used improper parameters in its testing, NHTSA does not 
find the results of this testing compelling and they do not warrant 
revisiting FMVSS No. 108. NHTSA therefore denies the petitions.

E. Transition Zone

    FMVSS No. 108 allows for a 1-degree transition zone between an area 
of reduced intensity and an area of unreduced intensity.\34\ The lower 
and upper beam photometric test points will not be applied within the 
transition zone (except for the upper beam maximum at H-V, which still 
applies throughout the entirety of the beam). Manufacturers are free to 
decide which portions of the roadway will receive an area of reduced or 
unreduced intensity, subject to several requirements or constraints 
(such as the track test that evaluates glare). This flexibility enables 
ADB systems to provide an area of reduced intensity not only to prevent 
glare to oncoming or preceding vehicles, but also in other situations 
in which reduced intensity would be beneficial (e.g., towards 
retroreflective signs, or on a wet roadway).
---------------------------------------------------------------------------

    \34\ 49 CFR 571.108 S9.4.1.6.4.5.
---------------------------------------------------------------------------

    SAE, Stanley, Koito, Valeo, NAL, the Alliance, Toyota, TSEI, IIHS, 
Volkswagen, and Honda all petitioned NHTSA to adjust the designation of 
a 1-degree transition zone between the headlamp's areas of reduced and 
unreduced intensity. Of those identified, SAE, Stanley, Valeo, the 
Alliance, Toyota, Volkswagen and TSEI explicitly petitioned that NHTSA 
increase the transition zone to 4 degrees. Valeo supported its petition 
by presenting an ADB pattern and its accompanying intensity scan of the 
H-H line, to demonstrate how transitioning from the area of reduced 
intensity to an area of full intensity in the upper beam portion of the 
ADB beam takes at least 4 degrees.\35\ Further, Valeo presented a 
comparative diagram of the UNECE and FMVSS No. 108 ADB implementation 
requirements to illustrate that the 1-degree transition zones will 
result in much larger areas of reduced intensity to meet the minimum 
requirements of the upper beam test points in the areas of unreduced 
intensity; Valeo stated this result effectively minimized the added 
safety benefits of ADB. Koito showed in its petition an iso-lux curve 
showing its ADB systems use approximately a 4-degree transition 
zone.\36\ NAL stated that not restricting ADB systems to a 1-degree 
transition zone could provide more light than the basic lower beam and 
potentially improve safety. Further, NAL and Koito also commented that 
NHTSA did not thoroughly explain the safety benefit of a 1-degree 
transition zone.
---------------------------------------------------------------------------

    \35\ See Docket No. NHTSA-2022-0013-0010, Figures 2-3.
    \36\ See Docket No. NHTSA-2022-0013-0007, Figure 1.
---------------------------------------------------------------------------

    Several petitioners \37\ shared that an overwhelming majority of 
current ADB systems in other foreign markets would fail to meet the 1-
degree transition zone requirement given the limits of the technology. 
Koito stated that the most popular and cost-effective ADB systems 
employ an optical system with shifting and overlapping segments of 
light, to ensure better visibility by enabling smooth transitions 
between the areas of reduced and unreduced intensity. Koito, among 
others, stated that these systems would fail to meet the standard. 
Toyota also commented that the photometry requirements would likely 
make systems more costly and slow development. Further, Toyota stated 
that only expensive, high-resolution pixelated ADB systems within 
premium vehicles can meet the current compliance standards for the 
transition zone. Additionally, NAL stated that SAE J3069 intentionally 
did not specify a width of the transition zone to permit different, 
less complicated, ADB systems and beam patterns as more than 80 percent 
of systems currently implemented by manufacturers are less complex. 
IIHS stated that NHTSA would contravene its stated technology-neutral 
approach by having a requirement that would strongly favor pixelated 
systems.
---------------------------------------------------------------------------

    \37\ SAE, Stanley, Valeo, the Alliance, NAL, Toyota, IIHS, 
Volkswagen and TSEI.
---------------------------------------------------------------------------

    Petitioners SAE and Koito suggested eliminating the transition zone 
entirely. TSEI requested NHTSA specify the size of the transition zone 
be greater than the minimum values specified for relevant lower beam 
test points (Table XIX, Headlamp Lower Beam Photometry Requirements) 
and less than the maximum specified at the HV for the upper beam (Table 
XVIII, Headlamp Upper Beam Photometry Requirements). TSEI stated this 
solution would more closely align, not only with SAE J3069, but also 
with the definition of a semi-automatic headlamp beam switching device, 
granting manufacturers more freedom to optimize ADB systems. Volkswagen 
stated in its petition that there are no known safety recalls, reported 
concerns or customer complaints with ADB in the rest of the world, 
which indicates an absence of safety issues with current ADB systems. 
According to Volkswagen, the exceptionally rigorous requirements for 
ADB in the United States through FMVSS No. 108 are not necessary.

[[Page 106372]]

Agency Response
    NHTSA is denying all the petitions that request a change to the 1-
degree transition zone allowance between the vehicle's headlamp areas 
of reduced and unreduced intensity. The transition zone plays a vital 
role in making the requirements practicable. In some cases, 
transitioning from lower beam intensities to upper beam intensities can 
represent a large change in photometric intensity. Achieving this 
transition is important to ensure that the adaptive beam pattern 
continues to serve the function of providing seeing distance, while 
also limiting glare. The angular size of this transition is critical to 
the beam's ability to meet these competing goals. A transition zone 
that is too large can create a problem in the beam pattern where either 
glare control or seeing distance is less than what is provided by the 
appropriate lower or upper beam, compromising safety.
    NHTSA determined that increasing the transition zone from 1-degree 
to 4-degree, as suggested by most of the petitioners, would reduce 
visibility below that provided by an upper beam even in common driving 
situations. Specifically, NHTSA found that over a 50 m range, the area 
of a 4-degree transition zone would extend 3.5 m wide and potentially 
cover the entirety of an adjacent lane. This limits the ability of the 
driver of an ADB equipped vehicle to navigate the roadway. NHTSA 
considered a simple interaction with a single oncoming vehicle that is 
positioned 50 m ahead in a lane to the left of the ADB equipped 
vehicle. In such a scenario, the adaptive beam will create an area of 
reduced intensity around the oncoming vehicle and will also create a 
transition zone to the left and right of that area of reduced 
intensity. If that transition zone extends 4 degrees beyond the end of 
the area of reduced intensity, it will not provide the upper beam 
photometric intensity until 3.5 m to the right of the oncoming vehicle 
(the area representing the ADB vehicle's travel lane). For a roadway 
with 3.0 m wide lane widths, the entirety of the ADB vehicle's travel 
lane (at a distance of 50 m) will be illuminated by the minimally 
regulated transition zone, which does not ensure proper object 
detection and undermines safety.
    With regard to the commenters' claims that FMVSS No. 108's 
transition zone requirement is overly stringent, costly, and only high-
resolution, pixelated ADB systems within premium vehicles can comply, 
NHTSA highlights that ADB headlight systems are optional. Because of 
the added costs associated with the technology, NHTSA does not 
anticipate that manufacturers would make these systems standard 
equipment in all vehicle models at this time. However, the 
practicability requirement in the National Traffic and Motor Vehicle 
Safety Act considers the technological ability of an industry to meet 
the goals of a particular standard. While ADB technology sufficient to 
meet the 1-degree transition zone may not yet be prevalent, compliance 
is feasible and demonstrated by specific premium models. NHTSA may also 
issue safety standards that are technology-forcing, requiring 
improvements in existing technology.\38\ While the transition zone 
requirements of FMVSS No. 108 are appropriately more rigorous than 
existing global requirements, revising FMVSS No. 108 to allow 
certification of ADB systems moves toward harmonization. By making ADB 
an optional technology, NHTSA incentivizes manufacturers to strive 
toward the increased safety and visibility advanced by the standard's 
rigor, while balancing reasonableness of cost and lead time.
---------------------------------------------------------------------------

    \38\ See Chrysler v. Department of Transportation, 472 F.2d 659 
(6th Cir. 1972).
---------------------------------------------------------------------------

F. Other

Momentary Exceedance Limit
    FMVSS No. 108 allows for a 0.1 second momentary glare exceedance 
allowance to account for vehicle pitch and other potentially 
uncontrolled noise in the measurement system.\39\ The momentary glare 
exceedance duration begins when the permitted maximum lux is exceeded 
and concludes in at least two ways: the illuminance value drops below 
the applicable glare limit; or the glare limit itself changes (i.e., 
increase). These outcomes could happen if the exceedance is experienced 
just before the glare limit changes. In either case, if the glare limit 
is not exceeded for more than 0.1 seconds, the exceedance will not be 
considered a noncompliance.
---------------------------------------------------------------------------

    \39\ 49 CFR 571.108 S14.9.3.12.2.1.
---------------------------------------------------------------------------

    Volkswagen petitioned NHTSA to increase the ADB systems exceedance 
limit. Volkswagen stated that the detection angle of the forward-facing 
cameras in NHTSA's testing of medium curve track scenarios, which 
resulted in glare exceedances, surpassed the capabilities of their 
existing ADB system cameras. Volkswagen stated that increasing the 
angle of detection of existing ADB system cameras, to keep the lux 
values within the illuminance limits and time exceedance at the far 
horizontal edges of the camera's detection zone, will detract from the 
system's performance and stability in the head-on area of the vehicle. 
According to Volkswagen, the compromised sensitivity will limit the ADB 
system from utilizing increased use of unreduced intensity light and 
limit safety benefits of enhanced visibility in all road scenarios. 
According to Volkswagen, consistently controlling glare to the far 
extreme horizontal edges of the angular visibility of the camera could 
be optimized by increasing the glare exceedance limit to a higher 
value.
    Volkswagen stated that a human driver's physical reaction time is 
approximately 1.0 second. Volkswagen referenced comments in the final 
rule preamble by the American Automobile Association (AAA), where it 
reported oncoming glare research showed exceedance of 1 second was 
rated as distracting to drivers.\40\ Volkswagen petitioned NHTSA to 
increase the minimum exceedance limit time from 0.1 seconds to 0.7 
seconds, which it states will allow the systems to have a more 
consistent and reliable detection performance.
---------------------------------------------------------------------------

    \40\ 87 FR 9940 (Feb. 22, 2022) Sec.  VIII.C.4 (Maximum 
Illuminance Criteria (Glare Limits)).
---------------------------------------------------------------------------

Momentary Exceedance Limit Agency Response
    NHTSA is denying the petitioner's request to increase the 0.1-
second momentary exceedance limit for ADB systems to 0.7 seconds. NHTSA 
established the 0.1-second glare exceedance allowance to account for 
testing-related variability caused by noise and uncontrolled test 
factors. For example, minor imperfections in the road surface can cause 
glare exceedances by affecting vehicle pitch. The testing conducted by 
NHTSA in support of the final rule does not show that glare from such 
sources lasts longer than 0.1 second.
    NHTSA does not agree with Volkswagen's comparison to a human 
driver's reaction time. The field of view (FOV) of the ADB system's 
camera is considerably narrower than that of a human observer, which is 
estimated at approximately 180[deg]. The narrower FOV will impact, and 
indeed improve, the ADB system's ability to quickly recognize and 
respond to oncoming stimuli. NHTSA considers any comparison with a 
human observer to be a false equivalency.
Large Radius of Curvature Track Testing
    FMVSS No. 108 specifies testing for oncoming glare over eight track 
test scenarios. The test scenarios involve the subject vehicle 
traveling towards the

[[Page 106373]]

fixture at various ranges of test speeds and road geometries of varying 
direction and curve radii, including large radii from 335m to 440m.\41\
---------------------------------------------------------------------------

    \41\ 87 FR 9928 (Feb. 22, 2022) Table 4 (Summary to the Proposed 
Track Test Scenarios). Testing is done with the vehicle traveling on 
a straight-path or on curves. The Radii of the curves vary as 
follows: Small = 85 m-115 m; Medium = 210 m-250 m; Large = 335 m-440 
m. The testing speed ranges vary based on scenario from 25 mph to 70 
mph.
---------------------------------------------------------------------------

    Volkswagen requested NHTSA remove the large radius curve test 
scenario from the standard. Volkswagen stated the vast majority of 
vehicle proving grounds do not offer such a large radius of curvatures. 
Volkswagen stated that there are currently only five facilities that 
are sufficiently large enough to conduct the final rule track testing. 
Volkswagen suggested NHTSA did not evaluate the ability of 
manufacturers or companies to conduct the testing at their own 
facilities and/or make accommodation for large radius curve test 
scenarios, which impose significant financial and time burdens. In 
addition, given NHTSA's preamble comments on IIHS using extrapolation 
for medium radius of curvature testing,\42\ Volkswagen inferred that 
similar extrapolation would be allowed for large radius test scenarios, 
making it redundant to include a specific track test as part of the 
regulation.
---------------------------------------------------------------------------

    \42\ 87 FR 9955 (Feb. 22, 2022) Sec.  VIII.C.8.d (Scenario 4: 
Oncoming Large Left Curve).
---------------------------------------------------------------------------

Large Radius of Curvature Track Testing Agency Response
    NHTSA is denying the petitioner's request to remove large radius 
curve testing scenarios from FMVSS No. 108. NHTSA was able to test on 
the curves specified in the final rule at the Transportation Research 
Center Vehicle Dynamics Area. This test facility is publicly available 
to manufacturers.
    A manufacturer must certify that its ADB system will meet the 
requirements specified in the standard if NHTSA tests it. As such, a 
manufacturer may use any valid means, including extrapolation, to 
certify if such a method proves valid through physical testing 
conducted by the NHTSA. Therefore, it is not necessary to remove the 
large radius curve test scenarios. Accordingly, manufacturers must 
exercise reasonable care in certifying that their vehicles will perform 
throughout the range of radii of curvature specified in the Table XXII. 
NHTSA will perform compliance testing using NHTSA facilities and it is 
the manufacturer's responsibility to ensure that it meets the 
performance requirements.
Headlamp Lens Cleaning
    The Alliance petitioned for the test vehicle preparation of the 
headlamps lenses to match the preparation for the ADB sensors and 
windshield.
Headlamp Lens Cleaning Agency Response
    The regulatory text states that to the extent practicable, the 
windshield and sensors will be clean and free from dirt and debris. The 
phase ``to the extent practicable'' does not appear in the vehicle 
preparation condition for a clean and debris free headlamp lens. This 
distinction acknowledges that it may not be practicable in some cases 
to clean the ADB sensors depending on the design of the vehicle. While 
Option 1 for headlamp beam switching devices in FMVSS No. 108 (classic 
semiautomatic beam switching device) is required to have an accessible 
lens for cleaning, no such requirement is applied to the ADB option. As 
such, a condition may exist in which NHTSA is unable to clean the ADB 
sensor. Considering this possibility, the ``to the extent practicable'' 
phase is included in the cleaning condition for that sensor. A 
comparable situation does not exist for headlamp lenses as FMVSS No. 
108 restricts the installation of headlamp obstructions. As such, NHTSA 
anticipates that it can clean the headlamp lenses before testing the 
ADB system as specified in the test procedure without issue.
Motorcycle ADB Requirements
    FMVSS No. 108 identifies the upper and lower beam photometry 
requirements for motorcycle headlamps and specifies that a motorcycle 
headlighting system must meet one of two options.\43\ One option is 
that it must satisfy one half of any passenger vehicle headlighting 
system of Table II, which provides both a full upper beam and full 
lower beam and is designed to conform to the requirements for that 
headlamp type. Alternatively, under the second option, the headlighting 
system may be designed to conform to requirements that are specific to 
motorcycles.
---------------------------------------------------------------------------

    \43\ 49 CFR 571.108 S10.17.
---------------------------------------------------------------------------

    Honda and Stanley requested NHTSA verify the application of ADB 
systems to motorcycles. They stated that the ADB requirements only 
mention photometry requirements in Tables XVIII and Table XIX, but not 
Table XX which includes photometry requirements for headlamps of 
motorcycles.
    Honda suggested that NHTSA modify the requirement to add Table XX 
to the relevant ADB sections of the standard (S9.4.1.6.4.[3-5]), while 
Stanley simply requested clarification on how to apply ADB to 
motorcycles.
Motorcycle ADB Requirements Agency Response
    NHTSA is denying the petitioners' requests to include motorcycle 
specific language in the final rule to validate motorcycle headlamp 
photometry compliance for ADB systems. NHTSA's lighting standard grants 
motorcycle headlighting systems two options to meet compliance. One of 
the options requires that the motorcycle headlighting system consist of 
one half of a headlighting system specified in Table II and conforms to 
the requirements for that headlamp type. This option can be used to 
ensure motorcycle headlamps meet the ADB requirements and not require 
change to the current regulatory text. NHTSA recognizes the 
requirements in Tables XVIII and XIX differ from those of Table XX; 
this difference is intentional and motorcycle lamps that incorporate 
ADB technology will need to comply with the requirements in Tables 
XVIII and XIX as they relate to motorcycles.

III. Petition for Reconsideration That Is Out of Scope

    Each semiautomatic headlamp switching device must include operating 
instructions to permit a driver to operate the device correctly. This 
requirement includes how to turn the automatic control on and off; how 
to adjust the sensitivity control (for Option 1 and, if provided, for 
Option 2); and any other specific instructions applicable to the 
device. Option 1 (``the classic system'') automatically switches 
between the upper and lower beam. Option 2 is the adaptive driving beam 
newly allowed by the revision of FMVSS No. 108. The recent revision to 
FMVSS No. 108 added the parenthetical ``(for Option 1 and, if provided, 
for Option 2)'' to the regulatory text to reflect that the requirement 
for sensitivity control instructions continue to apply to the classic 
system without change, but now also applies to adaptive driving beams 
if the adaptive driving beam is equipped with sensitivity control.
    The Alliance petitioned for a modification of the operating 
instructions to the semiautomatic beam switching devices. The Alliance 
petitioned to remove the sensitivity control instructions for the 
Option 1 semiautomatic beam switching device by modifying the 
regulatory text to say ``if provided'' for both Option 1 and Option 2. 
FMVSS No. 108 uses the language ``if provided'' only for Option 2, 
reflecting the intent to make no

[[Page 106374]]

changes to the classic semiautomatic beam switching devices 
requirements (Option 1), as compared to the previous versions of FMVSS 
No. 108. The scope of the recent FMVSS No. 108 revision pertained only 
to adaptive driving beams. As the request from the Alliance pertains to 
modification of the classic semiautomatic beam switching devices and 
those devices are not part of this ADB systems rulemaking action, NHTSA 
deems this request out of scope. NHTSA will not modify the 
requirements.

IV. Clarifications

    Several clarification questions were presented as part of the 
various petitions for reconsideration. NHTSA is taking this opportunity 
to answer some of these clarifying questions.
    First, NHTSA will zero-calibrate the photometers for the ADB track 
testing with the photometers installed on the test fixture and in the 
testing orientation. Doing so will allow NHTSA to more accurately 
measure the light provided by the test vehicle and filter out light 
from the environment.
    Second, NHTSA's zero-calibration process will subtract out light 
provided by the test fixture lighting itself. The lamps installed on 
the test fixture will illuminate the surroundings and, as such, some of 
that light will be reflected back onto the photometers. This light will 
not be counted as part of the measured light that is required to be 
less than the prescribed maxima. NHTSA's testing method also accounts 
for ambient conditions by measuring ambient illuminance either 
immediately before or after each test trial and subtracting that value 
from the recorded test data.
    Finally, NHTSA is clarifying that if a lower beam is part of the 
adaptive beam and horizontal aim is included in that lower beam, then 
it is excluded from the horizontal VHAD requirements in the same way as 
the adaptive beam is excluded. That is to say, a lower beam that is 
part of an adaptive beam and includes a horizontal aim need only meet 
the horizontal VHAD requirement to include references and scales 
relative to the longitudinal axis of the vehicle necessary to ensure 
correct horizontal aim for photometry and aiming purposes. It must 
include a ``0'' mark to indicate the alignment of the headlamps 
relative to the longitudinal axis of the vehicle and include an equal 
number of graduations from the ``0'' position representing equal 
angular changes in the axis relative to the vehicle axis. The remaining 
horizontal VHAD requirements that would apply to a lower beam that is 
not part of an adaptive beam do not apply in such a scenario 
(S10.18.8.1.2.1 through S10.18.8.1.2.4).

V. Conclusion

    For the reasons discussed above, the agency denies the Petitioners' 
petitions for reconsideration of the February 22, 2022, final rule (87 
FR 9916).

    Issued in Washington, DC, under authority delegated in 49 CFR 
1.95 and 501.
Adam Raviv,
Chief Counsel.
[FR Doc. 2024-31141 Filed 12-27-24; 8:45 am]
BILLING CODE 4910-59-P
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