Federal Register / Vol. 89, No. 249 / Monday, December 30, 2024 / Rules and Regulations 106365 

1 83 FR 51766, (Oct. 12, 2018). 

ACTION: Interim rule; extension of 

comment period. 

SUMMARY: DoD, GSA, and NASA issued 

an interim rule on November 12, 2024, 

amending the Federal Acquisition 

Regulation (FAR) to implement a 

prohibition on the procurement and 

operation of unmanned aircraft systems 

manufactured or assembled by an 

American Security Drone Act-covered 

foreign entity. The deadline for 

submitting comments is being extended 

from January 13, 2025, to January 27, 

2025, to provide additional time for 

interested parties to provide comments 

on the proposed rule. The effective date 

of this rule is not being changed and 

remains November 12, 2024. 

DATES: For the interim rule published 

on November 12, 2024, (89 FR 89464), 

the deadline to submit comments is 

extended. Submit comments by January 

27, 2025. 

ADDRESSES: Submit comments in 

response to FAC 2025–01, FAR Case 

2024–002 to the Federal eRulemaking 

portal at https://www.regulations.gov by 

searching for ‘‘FAR Case 2024–002’’. 

Select the link ‘‘Comment Now’’ that 

corresponds with ‘‘FAR Case 2024– 

002’’. Follow the instructions provided 

on the ‘‘Comment Now’’ screen. Please 

include your name, company name (if 

any), and ‘‘FAR Case 2024–002’’ on your 

attached document. If your comment 

cannot be submitted using https://

www.regulations.gov, call or email the 

points of contact in the FOR FURTHER

INFORMATION CONTACT section of this 

document for alternate instructions. 

Instructions: Please submit comments 

only and cite ‘‘FAR Case 2024–002’’ in 

all correspondence related to this case. 

Comments received generally will be 

posted without change to https://

www.regulations.gov, including any 

personal and/or business confidential 

information provided. Public comments 

may be submitted as an individual, as 

an organization, or anonymously (see 

frequently asked questions at https://

www.regulations.gov/faq). To confirm 

receipt of your comment(s), please 

check https://www.regulations.gov, 

approximately two-to-three days after 

submission to verify posting. 

FOR FURTHER INFORMATION CONTACT: For 

clarification of content, contact Mr. 

Benjamin Collins, Procurement Analyst, 

at 850–826–0058 or by email at 

benjamin.collins@gsa.gov. For 

information pertaining to status, 

publication schedules, or alternate 

instructions for submitting comments if 

https://www.regulations.gov cannot be 

used, contact the Regulatory Secretariat 

Division at 202–501–4755 or 

GSARegSec@gsa.gov. Please cite FAC 

2025–01, FAR Case 2024–002. 

SUPPLEMENTARY INFORMATION: 

I. Background 

DoD, GSA, and NASA published an 

interim rule in the Federal Register at 

89 FR 89464 on November 12, 2024. The 

comment period is extended to January 

27, 2025, to allow additional time for 

interested parties to develop comments 

on this rule. The effective date of this 

rule is not being changed and remains 

November 12, 2024. 

List of Subjects in 48 CFR Parts 4, 13, 

39, 40, and 52 

Government procurement. 

William F. Clark, 

Director, Office of Government-wide 

Acquisition Policy, Office of Acquisition 

Policy, Office of Government-wide Policy. 

[FR Doc. 2024–30937 Filed 12–27–24; 8:45 am] 

BILLING CODE 6820–EP–P 

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. 

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: Adam.Lowery@dot.gov; For legal 

issues, you may contact Evita St. Andre, 

Office of Chief Counsel, Telephone: 

(202) 366–2992, Email: Evita.St.Andre@

dot.gov. 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 


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2 87 FR 9916, (Feb. 22, 2022). 

3American Honda Motor Co., Inc., Docket 

No.2022–0013–0011. 

4 Volkswagen Group of America, Docket 

No.2022–0013–0012. 

5Toyota Motor North American, Inc., Docket 

No.2022–0013–0015. 

6Ford Motor Company, Docket No.2022–0013– 

0016. 

7 Koito Manufacturing Co. LTD, Docket No.2022– 

0013–0007. 

8Stanley Electric Co. LTD, Docket No.2022– 

0013–0008. 

9North American Lighting, Docket No.2022– 

0013–0009. 

10 Valeo Lighting Systems, Docket No.2022–0013– 

0010. 

11Alliance for Automotive Innovation, Docket 

No.2022–0013–0013. 

12Transportation Safety Equipment Institute, 

Docket No.2022–0013–0014. 

13SAE International—Lighting Systems Group, 

Docket No.2022–0013–0005. 

14 Insurance Institute of Highway Safety— 

Highway Loss Data Institute, Docket No.2022– 

0013–0017. 

15See 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.’’). 

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 

increases visibility, thereby improving 

safety. NHTSA assessed comments 

received in response to the NPRM and 

published a final rule on February 22, 

2022. 

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. 

FMVSS No. 108 has two main 

components that ensure ADB systems 

operate safely: (1) vehicle-level tracktest 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. 

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. 

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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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.’’). 

17A photometer, or illuminance meter, is an 

instrument that measures light. 

18See 87 FR 9996 (Feb. 22, 2022) Table 15 

(Summary of Major Differences Between the Final 

Rule and SAE J3069). 

19MY2018 Toyota Camry, Ford F–150, Harley 

Davidson Sportster. 

20Among 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. 

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 realworld representative lighting in the test 

procedure by specifying original 

equipment vehicle headlamps and 

taillamps mounted on test fixtures.18

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

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 realworld 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. 

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 componentlevel 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 


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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). 

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 componentlevel 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. 

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. Componentlevel 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 componentlevel 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 


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22For 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. 

24See 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. 

25Specifically SAE, Stanley, Toyota, Ford, TSEI, 

NAL, IIHS, Valeo, Volkswagen, Koito and the 

Alliance. 

26See Docket No. NHTSA–2022–0013–0016; 

Appendix A. 27See 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) 28Ford 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. 

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

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. 

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 componentlevel 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

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, 


ddrumheller on DSK120RN23PROD with RULES1
106370 Federal Register / Vol. 89, No. 249 / Monday, December 30, 2024 / Rules and Regulations 

29See Docket No. NHTSA–2022–0013–0010, 

Figures 5–7. 

30See Docket No. NHTSA–2022–0013–0015, 

Figure 1. 

31See 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 frontallighting systems). 

32NHTSA–2018–0090–0162; NHTSA–2018– 

0090–0138. 

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. 

Toyota presented a similar analysis, 

characterizing the pitch of a highmounted 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. 

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 longerdistance 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

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

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 


ddrumheller on DSK120RN23PROD with RULES1
Federal Register / Vol. 89, No. 249 / Monday, December 30, 2024 / Rules and Regulations 106371 

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 rightside. 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. 

34 49 CFR 571.108 S9.4.1.6.4.5. 

35See Docket No. NHTSA–2022–0013–0010, 

Figures 2–3. 

36See Docket No. NHTSA–2022–0013–0007, 

Figure 1. 

37SAE, Stanley, Valeo, the Alliance, NAL, 

Toyota, IIHS, Volkswagen and TSEI. 

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. 

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 sideview 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). 

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. 

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 technologyneutral approach by having a 

requirement that would strongly favor 

pixelated systems. 

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 semiautomatic 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. 


ddrumheller on DSK120RN23PROD with RULES1
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38See Chrysler v. Department of Transportation, 

472 F.2d 659 (6th Cir. 1972). 39 49 CFR 571.108 S14.9.3.12.2.1. 

40 87 FR 9940 (Feb. 22, 2022) § VIII.C.4 

(Maximum Illuminance Criteria (Glare Limits)). 

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. 

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. 

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. 

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°. 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 


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Federal Register / Vol. 89, No. 249 / Monday, December 30, 2024 / Rules and Regulations 106373 

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. 

42 87 FR 9955 (Feb. 22, 2022) § VIII.C.8.d 

(Scenario 4: Oncoming Large Left Curve). 43 49 CFR 571.108 S10.17. 

fixture at various ranges of test speeds 

and road geometries of varying direction 

and curve radii, including large radii 

from 335m to 440m.41

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. 

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. 

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 


ddrumheller on DSK120RN23PROD with RULES1
106374 Federal Register / Vol. 89, No. 249 / Monday, December 30, 2024 / Rules and Regulations 

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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