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[Federal Register Volume 89, Number 228 (Tuesday, November 26, 2024)]
[Rules and Regulations]
[Pages 93199-93220]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2024-27349]

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DEPARTMENT OF TRANSPORTATION

National Highway Traffic Safety Administration

49 CFR Parts 571

[Docket No. NHTSA-2023-0021]
RIN 2127-AM37

Federal Motor Vehicle Safety Standards; Automatic Emergency 
Braking Systems for Light Vehicles

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

ACTION: Final rule; response to petitions for reconsideration.

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SUMMARY: This document grants parts of petitions for reconsideration of 
a May 9, 2024, final rule that adopted Federal Motor Vehicle Safety 
Standard (FMVSS) No. 127, ``Automatic Emergency Braking for Light 
Vehicles,'' which requires automatic emergency braking (AEB), 
pedestrian automatic emergency braking (PAEB), and forward collision 
warning (FCW) systems on all new light vehicles. This final rule 
clarifies requirements applicable to FCW visual signals and audio 
signals, corrects an error in the test scenario for obstructed 
pedestrian crossing the road, and removes superfluous language from the 
performance test requirement for lead vehicle AEB. This notice denies 
other requests in the petitions. This document also denies a petition 
for reconsideration, which is treated as a petition for rulemaking 
because it was received more than 45 days after publication of the 
rule.

DATES: 
    Effective: January 27, 2025.
    Compliance date: Compliance with FMVSS No. 127 and related 
regulations, as amended in this rule, is required for all vehicles by 
September 1, 2029. However, vehicles produced by small-volume 
manufacturers, final-stage manufacturers, and alterers must be equipped 
with a compliant AEB system by September 1, 2030.
    Petitions for reconsideration: Petitions for reconsideration of 
this final action must be received not later than January 10, 2025.

ADDRESSES: Correspondence related to this rule, including petitions for

[[Page 93200]]

reconsideration and comments, should refer to the docket number set 
forth above (NHTSA-2023-0021) and be submitted to the Administrator, 
National Highway Traffic Safety Administration, 1200 New Jersey Avenue 
SE, Washington, DC 20590.

FOR FURTHER INFORMATION CONTACT: For technical issues: Mr. Markus 
Price, Office of Crash Avoidance Standards, Telephone: (202) 366-1810, 
Facsimile: (202) 366-7002. For legal issues: Mr. Eli Wachtel, Office of 
the Chief Counsel, Telephone: (202) 366-2992, Facsimile: (202) 366-
3820. The mailing address for these officials is: National Highway 
Traffic Safety Administration, 1200 New Jersey Avenue SE, Washington, 
DC 20590.

SUPPLEMENTARY INFORMATION: 

Table of Contents

I. Background and Executive Summary
II. Petitions for Reconsideration Received by NHTSA and Analysis
    A. No Contact
    B. Multiple Trials
    C. Equipment Requirement
    D. Unlimited Preconditioning and Test Runs
    E. Malfunction Indicator Lamp
    F. Deactivation
    G. Obstructed Pedestrian Crossing Test Correction
    H. FCW Auditory Signal
    I. FCW Visual Signal
    J. Cost Estimates
    K. Brake Pedal Robot
    L. Manual Transmission
    M. Small-Volume Manufacturers
III. Petition for Rulemaking Received by NHTSA and Analysis
    A. Include V2X
IV. Rulemaking Analyses and Notices
V. Regulatory Text

I. Background and Executive Summary

    In November 2021, the Bipartisan Infrastructure Law (BIL), enacted 
as the Infrastructure Investment and Jobs Act (Pub. L. 117-58), was 
signed into law. BIL directed the Secretary of Transportation to 
promulgate a rule to establish minimum performance standards with 
respect to crash avoidance technology and to require that all passenger 
motor vehicles manufactured for sale in the United States be equipped 
with forward collision warning (FCW) and automatic emergency braking 
(AEB) systems that alert the driver if a collision is imminent and 
automatically apply the brakes if the driver fails to do so.
    In accordance with BIL, NHTSA issued a Notice of Proposed 
Rulemaking (NPRM) (88 FR 38632) in June 2023, followed by a final rule 
(89 FR 39686) in May 2024, establishing FMVSS No. 127, ``Automatic 
Emergency Braking Systems for Light Vehicles.'' This FMVSS requires 
AEB, including pedestrian AEB (PAEB), systems on light vehicles. In 
addition to the mandate in BIL, the final rule was also issued under 
the authority of the National Traffic and Motor Vehicle Safety Act of 
1966 (Safety Act). Under 49 U.S.C. chapter 301, the Secretary of 
Transportation is responsible for prescribing motor vehicle safety 
standards that are practicable, meet the need for motor vehicle safety, 
and are stated in objective terms. The responsibility for promulgation 
of FMVSSs is delegated to NHTSA.
    The final rule includes four requirements for AEB systems for both 
lead vehicles and pedestrians. First, there is an equipment requirement 
that vehicles have an FCW system that provides an auditory and visual 
signal to the driver of an impending collision with a lead vehicle or a 
pedestrian. The system must operate at any forward speed greater than 
10 km/h (6.2 mph) and less than 145 km/h (90.1 mph) for a warning 
involving a lead vehicle, at any forward speed greater than 10 km/h 
(6.2 mph) and less than 73 km/h (45.3 mph) for a warning involving a 
pedestrian. Similarly, the final rule includes an equipment requirement 
that light vehicles have an AEB system that applies the brakes 
automatically when a collision with a lead vehicle or pedestrian is 
imminent. The system must operate at any forward speed that is greater 
than 10 km/h (6.2 mph) and less than 145 km/h (90.1 mph) for AEB 
involving a lead vehicle, and at any forward speed greater than 10 km/h 
(6.2 mph) and less than 73 km/h (45.3 mph) for PAEB.
    Second, the AEB system is required to prevent the vehicle from 
colliding with the lead vehicle or pedestrian test devices when tested 
according to the standard's test procedures. These track test 
procedures have defined parameters, including travel speeds up to 100 
km/h (62.2 mph), that ensure that AEB systems prevent crashes in a 
controlled testing environment.
    Third, the final rule includes two false activation tests.
    Finally, the final rule requires that a vehicle must detect AEB 
system malfunctions, including performance degradation caused solely by 
sensor obstructions, and notify the driver of any malfunction that 
causes the AEB system not to meet the minimum proposed performance 
requirements. If the system detects a malfunction, or if the system 
adjusts its performance such that it will not meet the requirements of 
the finalized standard, the system must provide the vehicle operator 
with a telltale notification.
    The final rule applies to vehicles manufactured on or after 
September 1, 2029. An additional year is provided for small-volume 
manufacturers.

Petitions for Reconsideration Received

    NHTSA regulations allow any interested person to petition the 
Administrator for reconsideration of a rule. Under NHTSA's regulations, 
petitions for reconsideration must provide an explanation why 
compliance with the rule is not practicable, is unreasonable, or is not 
in the public interest. Additionally, petitions must be received within 
45 days of the publication of the final rule. Untimely petitions for 
reconsideration are considered to be petitions for rulemaking. The 
Administrator may consolidate petitions relating to the same rule.\1\
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    \1\ 49 CFR 553.35, 553.37.
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    NHTSA received petitions for reconsideration from the Alliance for 
Automotive Innovation (the Alliance),\2\ Toyota Motor North America 
(Toyota),\3\ Volkswagen Group of America (Volkswagen),\4\ and Scuderia 
Cameron Glickenhaus, LLC (Glickenhaus).\5\ NHTSA also received a letter 
from Hyundai Motor Group (Hyundai), styled as a ``supplemental 
comment,'' that provides its perspective on FMVSS No. 127, which we 
have considered in this response to the petitions for 
reconsideration.\6\ NHTSA also received a petition from Autotalks that 
NHTSA is treating as a petition for rulemaking because it was received 
more than 45 days after publication of the final rule.\7\ The petitions 
requested a variety of amendments to FMVSS No. 127. These, and NHTSA's 
reasoning and response to each petitioned-for item, are summarized 
below and discussed in detail in the respective sections of the 
preamble of this notice.
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    \2\ Alliance for Automotive Innovation, Docket No. NHTSA-2023-
0021-1071.
    \3\ Toyota Motor North America, Docket No. NHTSA-2023-0021-1074.
    \4\ Volkswagen Group of America, Docket No. NHTSA-2023-0021-
1073.
    \5\ Scuderia Cameron Glickenhaus, Docket No. NHTSA-2023-0021-
1078.
    \6\ Hyundai Motor Group, Docket No. NHTSA-2023-0021-1072.
    \7\ Autotalks, Docket No. NHTSA-2023-0021-1075.
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Summary of Responses to the Petitions for Reconsideration

    In response to these petitions, NHTSA is granting in part and 
denying in part. The changes made to FMVSS No. 127 are summarized as 
follows.

[[Page 93201]]

     FMVSS No. 127 contains an equipment requirement that AEB 
systems activate the service brakes when a collision is imminent and 
that they operate under certain conditions. It also contains a 
performance test requirement for lead vehicle AEB that contains similar 
language. Petitioners requested definitions for the terms ``operate'' 
and ``imminent.'' NHTSA is amending the language in the performance 
test requirement to remove refence to ``imminent'' from the performance 
test requirement for lead vehicle AEB, to clarify that the performance 
test does not evaluate AEB activation timing. NHTSA is not providing a 
definition for ``operate'' because the definition of ``automatic 
emergency braking system'' in the final rule sufficiently describes how 
an AEB system operates. NHTSA is not providing a definition for 
``imminent'' because the term is used consistent with its plain 
meaning.
     FMVSS No. 127 contains a test scenario that, when tested 
with very narrow vehicles at the extreme of the tolerances allowed by 
the test condition, resulted in a stringency beyond that intended by 
NHTSA. This final rule amends the test scenario to ensure the correct 
level of stringency.
     FMVSS No. 127 contains specifications for the FCW visual 
signal location. Petitioners requested additional clarity. This final 
rule amends the regulatory text to clarify these specifications.
     FMVSS No. 127 contains requirements for the FCW audio 
signal, including that in-vehicle audio must be suppressed when the FCW 
auditory signal is presented. Petitioners expressed several concerns 
about the clarity and objectivity of these requirements as well as test 
conditions. This final rule clarifies these requirements by stating the 
location of the microphone, additional vehicle conditions under which 
testing will occur, and amending the definitions to simplify the 
requirement for suppression.
    This rule also denies the petitions with regards to several other 
requested amendments. These are as follows. For the items for which 
petitioners restate arguments made during the comment period for FMVSS 
No. 127, the reasons given for denial are the same as those stated in 
the final rule.
     The performance requirement for both lead vehicle and 
pedestrian AEB testing is collision avoidance (referred to throughout 
the final rule and this document as ``no contact''). Petitioners 
requested relaxation of this requirement to allow contact at low 
speeds, specifically requesting 10 km/h (6.2 mph). NHTSA is rejecting 
this request because the no contact requirement is practicable and 
meets the need for safety.
     Petitioners requested that multiple test runs be allowed 
to achieve the no contact performance requirement (for example, that 
vehicles must pass on 5 out of 7 test runs) to account for variability. 
Petitioners noted that FMVSS No. 135, which regulates light vehicle 
brake systems, allows multiple test runs to meet some of the 
performance requirements. NHTSA is rejecting this request because FMVSS 
No. 127 testing is distinct from FMVSS No. 135 testing such that not 
allowing multiple test runs in FMVSS No. 127 is practicable and meets 
the need for safety.
     FMVSS No. 127 test scenarios state that the vehicle can be 
driven for any amount of time. Additionally, it does not place a cap on 
the number of tests that could be run on any given subject vehicle. 
Petitioners expressed concern that this standard would allow excessive 
driving or testing of vehicles to wear out components such that they 
can no longer meet the performance required by the standard. NHTSA 
finds further specification is unnecessary because the test does not 
evaluate the endurance or durability of wear parts and will not be used 
in such a manner.
     FMVSS No. 127 requires that vehicles illuminate a 
malfunction identification lamp (MIL) upon detection of a malfunction 
or if the AEB system adjusts its performance such that it is below the 
performance required by the standard. Petitioners requested additional 
specificity regarding the terminology in this requirement as well as a 
test procedure. NHTSA is rejecting this request because the requirement 
meets the Safety Act as written.
     FMVSS No. 127 does not permit installation of a manual 
control with the sole purpose of deactivating the AEB system. It does 
contain a provision allowing automatic deactivation in certain 
situations. Petitioners requested permission to install a manual 
deactivation control, as well as modifications to the automatic 
deactivation provision. NHTSA is rejecting this request because the 
final rule already addresses petitioners' concerns.
     Petitioners stated that NHTSA did not fully consider costs 
associated with compliance. No change is needed in response to this 
request because the final rule fully considered the costs associated 
with compliance.
     Volkswagen requested additional specifications for the 
brake pedal robot used in testing with manual brake application. NHTSA 
is rejecting this request for the reasons stated in the May 9, 2024 
final rule.
     Petitioner Glickenhaus requested the AEB requirements not 
be applicable to vehicles with manual transmission. NHTSA is rejecting 
this request because vehicles equipped with manual transmissions and 
AEB are widely available.
     Petitioner Glickenhaus requested additional flexibility 
for very small volume manufacturers. NHTSA is rejecting this request 
because AEB systems are available for purchase and, in the case that a 
manufacturer is unable to acquire systems, the exemption processes in 
the Safety Act may provide relief.

II. Petitions for Reconsideration Received by NHTSA and Analysis

A. No Contact

    The final rule requires that, when tested according to the 
procedures therein, the subject vehicle not collide with the test 
device (vehicle test device or pedestrian mannequin). The test data, 
discussed at length in the final rule, demonstrates that this 
requirement is practicable. A tested vehicle was able to meet the 
performance requirements in the final rule and recent NHTSA testing 
revealed significant improvement throughout much of the fleet in a 
relatively short time. These facts show that compliance by 2029 is 
practicable.
    In the final rule we also emphasized that practicability must be 
viewed from the perspective that under the Safety Act, NHTSA has the 
authority to issue standards that are technology-forcing.\8\ That is, 
NHTSA is empowered under the Safety Act to issue safety standards that 
``impel automobile manufacturers to develop and apply new technology to 
the task of improving the safety design of automobiles as readily as 
possible'' such that they ``require improvements in existing technology 
or which require the development of new technology, and is not limited 
to issuing standards based solely on devices already fully developed.'' 
\9\ NHTSA acknowledged that the final rule is technology-forcing, but 
emphasized that the standard is practicable and no single current 
vehicle must meet every requirement for an FMVSS to be considered 
practicable under the Safety Act.
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    \8\ Chrysler Corp. v. Dep't of Transp., 472 F.2d 659 (6th Cir. 
1972) (Chrysler).
    \9\ Id. at 671, 673.
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    Petitioners requested reconsideration on two broad grounds: first 
that the no-contact requirement is not practicable,

[[Page 93202]]

and second that it does not meet the need for safety.
1. Practicability and Test Data
a. PAEB and AEB Test Data
    The Alliance stated that NHTSA has not demonstrated that the no 
contact requirement is practicable for the fleet. Other than the 
simulation data for the obstructed pedestrian crossing road scenario, 
the Alliance did not present any new data or analysis regarding the 
practicability of requiring collision avoidance in AEB compliance 
testing that the agency had not previously considered.\10\ The Alliance 
noted that the final rule states that NHTSA agrees with the IIHS's 
comment to the NPRM that some current AEB systems are already 
completely avoiding collisions under the proposed AEB testing. The 
Alliance added, however, that IIHS did not test any vehicles at speeds 
faster than 70 km/h (43.5 mph), and only three out of the six tested 
vehicles could avoid the lead vehicle target in all of the test runs. 
It also stated that NHTSA conceded that no vehicle in its 2020 AEB 
research was able to meet all the performance requirements of the final 
rule for lead vehicle and PAEB systems. It also pointed out that for 
lead vehicle AEB systems, NHTSA's MY 2023 research showed that only one 
vehicle could avoid contact in each test speed and scenario, but even 
that vehicle did not avoid contact on every test run at the most 
stringent condition. The Alliance argued that a single vehicle's 
ability to meet the required tests some of the time does not support 
NHTSA's conclusion that the no-contact requirement is practicable. The 
Alliance also stated that the vehicles used in NHTSA's 2023 testing 
don't support the final rule because those vehicles were designed only 
to meet the performance levels stated in the 2016 voluntary 
commitment.\11\
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    \10\ The obstructed pedestrian crossing road scenario is 
discussed in detail in Section II.G, ``Obstructed Pedestrian 
Crossing Test Correction,'' of this notice.
    \11\ In March 2016, NHTSA and the Insurance Institute for 
Highway Safety (IIHS) announced a commitment by 20 manufacturers 
representing more than 99 percent of the U.S. light vehicle market 
to include low-speed AEB as a standard feature on nearly all new 
light vehicles not later than September 1, 2022. As part of this 
voluntary commitment, manufacturers are including both FCW and a 
crash imminent braking (CIB) system that reduces a vehicle's speed 
in certain rear-end crash-imminent test conditions.
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    The Alliance stated the agency's analysis of test data demonstrate 
variation in performance that was not accounted for in the final rule. 
The Alliance stated that the final rule did not consider whether 
variability between vehicles or testing locations would make compliance 
more challenging by dictating the design margin that manufacturers need 
to meet to comply with the requirement. The Alliance reasoned that 
NHTSA's evaluation (in the FRIA) of the variability in time-to-
collision (TTC) at brake activation demonstrates that this variability 
is meaningful and demonstrates variation in performance. The Alliance 
noted that NHTSA research that was conducted with three vehicles at the 
speed range from 16 km/h (9.9 mph) to 40 km/h (24.9 mph) showed a 
variation of at least 0.15 seconds in TTC at brake activation.
Agency Analysis
    The test data demonstrates that the rule is practicable. In its 
petition, the Alliance acknowledged that NHTSA had considered all 
available information and test results from the agency's research and 
studies conducted by stakeholders such as IIHS. It also acknowledged 
that a tested vehicle was able to meet the performance requirements, 
despite not being designed to meet the requirements of the final rule. 
Additionally, the vehicle that was able to meet the requirements had a 
sales price below the market average, indicating that the requirements 
could be met without expensive new technologies.
    NHTSA's recent testing also marked significant progress compared to 
its earlier research from 2020. The positive trend in AEB technology 
was further supported by IIHS, which highlighted substantial 
improvements between the 2023 and 2024 model years in the stationary 
lead vehicle test at 70 km/h (43.5 mph).\12\ Notably, the percentage of 
vehicles avoiding the target in all test runs increased from 10 percent 
to 56 percent. These data all show that meeting the requirements of 
this rule by September 2029 is practicable.\13\
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    \12\ NHTSA-2023-0021-1076.
    \13\ Additionally, in the final rule we emphasized several other 
reasons that inform the practicability of selecting a no contact 
requirement over a requirement that allows contacts, such as testing 
repeatability and costs associated with replacing or repairing test 
vehicles and test devices.
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    Additionally, the Alliance's framing of vehicle and test location 
variability and our FRIA estimates is unconvincing. Variability between 
vehicles in the same model line and year (vehicle-to-vehicle 
variability) is determined by the manufacturer, subject to the 
requirement that every vehicle it sells meet the minimum safety 
performance. NHTSA has no reason to believe that the vehicles we tested 
had superior performance to other vehicles in the same model line and 
year. Also, vehicle-to-vehicle variability is a consideration for all 
FMVSS, and the Alliance provided no information to indicate that there 
is an issue unique to AEB. Additionally, variation in brake activation 
timing between manufacturers is contemplated by the structure of the 
rule. The final rule does not dictate brake activation timing, brake 
force, or any other aspects of AEB performance other than that the 
subject vehicle not make contact with the test device.
    Regarding variability across test locations, FMVSS No. 127 
specifies all the needed conditions to inform manufacturers of how we 
will test. These conditions were proposed in the NPRM, and commenters 
did not raise conditions that were not included that would affect test 
outcomes. Finally, the variability analysis in the FRIA is our attempt 
to connect the idealized test conditions to the real world when 
conducting benefits analyses. NHTSA understands that in the real world 
there will be variability that cannot be tested in an efficient way 
through an FMVSS, which informs our benefits calculations. However, 
such analysis should not be used to determine the types of results 
achievable in an idealized testing environment. For these reasons, 
NHTSA will not grant reconsideration.
b. FMVSS No. 135 Test Data
    The Alliance stated that the final rule improperly relied on the 
agency's evaluation of FMVSS No. 135 test results, which showed that 
braking performance of nearly all tested vehicles was much better than 
what the FMVSS requires. The Alliance stated that the evaluation 
reflects that manufacturers build compliance margins into their design 
for FMVSS compliance and does not support the agency's conclusion that 
the no-contact requirement is practicable. Furthermore, the Alliance 
stated that test results from FMVSS No. 135 testing are not comparable 
to AEB performance because the final rule requires performance from 
both the service brakes and a perception system, whereas FMVSS No. 135 
evaluates only service brake performance. Also, the Alliance stated 
that the maneuvers in FMVSS No. 135 tests are conducted with a human 
driver putting muscular effort into the brake pedal. In contrast, there 
is no human input when testing the AEB system.
Agency Analysis
    NHTSA's use of FMVSS No. 135 test results was justified. As an 
initial matter, those results were not the primary results upon which 
the agency

[[Page 93203]]

determined that the requirements are practicable. They were used 
largely to show that the braking performance needed to meet the 
requirements in the final rule is present in the current fleet without 
the need for changes, especially with regard to heavier vehicles for 
which there were limitations on available test data. The results 
indicated that the brake performance of most vehicles surpasses the 
performance requirements set by FMVSS No. 135. While the results of 
these tests might not show exactly how the braking systems will perform 
under automatic actuation that does not involve human muscular inputs, 
they do demonstrate that braking performance is more than sufficient to 
permit compliance with the final rule. Indeed, we do not need to rely 
on FMVSS No. 135 test data to demonstrate actuation performance because 
AEB systems currently on the road and tested by NHTSA actuate the 
service brakes without human driver inputs and demonstrate the 
performance needed to meet FMVSS No. 127. Therefore, we disagree with 
the Alliance's contention that the final rule misused the FMVSS No. 135 
test results.
c. Test Speeds and Headway
    Toyota, Volkswagen, and the Alliance expressed concern regarding 
the practicability of high maximum test speeds and no contact. The 
Alliance stated that NHTSA's data illustrate the difficulties in 
complying with the decelerating lead vehicle test with both the lead 
and subject vehicles traveling at 50 mph (80 km/h) at any headway 
between 12 and 40 meters (S7.5.1(a), S7.5.2(b)(2), S7.5.3(a) and 
S7.5.3(d) of the final rule). To address this issue, the Alliance 
petitioned NHTSA to consider reducing the maximum test speed for the 
AEB and PAEB requirements and adjust the headway requirements. The 
Alliance claimed that the 2023 additional AEB research in the final 
rule evaluated only the test condition with a 12-meter headway and did 
not provide any test data to support the lead vehicle decelerating test 
with headways greater than 12 meters.
Agency Analysis
    NHTSA is not reducing the maximum test speeds or adjusting the 
headway requirements for the test scenarios. Petitioners' requests for 
test speed reduction were addressed in the final rule, and headways 
above 12 meters are practicable.
    Regarding test speeds, NHTSA's 2023 research showed multiple 
vehicles avoided contact on most tests regardless of scenario and test 
speed.\14\ Further, one vehicle avoided contact on all lead vehicle AEB 
and PAEB tests except on three of the five lead vehicle decelerating 
tests, where it impacted the lead vehicle at approximately 5 km/h or 
less. \15\ That vehicles not designed to meet the standard are already 
capable of doing so demonstrates that the performance test requirements 
are practicable.
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    \14\ NHTSA's 2023 Light Vehicle Automatic Emergency Braking 
Research Test Summary, Docket No. NHTSA-2023-0021-1066; NHTSA's 2023 
Light Vehicle Pedestrian Automatic Emergency Braking Research Test 
Summary, Docket No. NHTSA-2023-0021-1068.
    \15\ The low impact speeds on the system that did not avoid 
contact on all trials suggests that slight tuning of that AEB to the 
requirements of FMVSS No. 127 is needed to meet the standard.
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    Regarding headway for the lead vehicle decelerating test, the 
headway ranges selected are consistent with those used by Euro NCAP and 
NHTSA incorporated the test ranges for speed and headways to ensure AEB 
system robustness under a range of situations. NHTSA tested 2022 model 
year vehicles with headways of 40 m with and without manual brake 
application at 50 km/h and 80 km/h, and with a lead vehicle 
deceleration of 0.4 g and 0.5 g.\16\ During that testing, multiple 
vehicles avoided contact in almost all lead vehicle decelerating test 
scenarios and one vehicle avoided contact in all scenarios. 
Additionally, the shorter headway tests are generally more stringent 
than tests with larger headways. In our 2023 testing, one vehicle 
tested by NHTSA avoided contact in the 80 km/h lead vehicle 
deceleration test in all trials with a 12 m headway, and another 
vehicle avoided contact on 2 out of 5 runs,\17\ suggesting that 
avoiding contact under less stringent test conditions is practicable. 
Based on our test data, the requirements are practicable and will not 
be adjusted.
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    \16\ NHTSA's 2022 Light Vehicle Automatic Emergency Braking 
Research Test Summary, Docket No. NHTSA-2023-0021-0005.
    \17\ NHTSA's 2023 Light Vehicle Automatic Emergency Braking 
Research Test Summary, Docket No. NHTSA-2023-0021-1066.
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2. Meet the Need for Safety
    Petitioners requested reconsideration of the no contact 
requirement, stating that it could lead to unintended consequences such 
as increased false positives and a rise in rear-end collisions. A false 
positive describes AEB system brake applications in circumstances where 
there is no crash-imminent situation, such as braking in the absence of 
a true obstacle.
a. Sufficiency of Analysis of False Positives
    The Alliance stated that NHTSA has not adequately considered 
whether meeting the no-contact performance requirement will generate 
false positives and that NHTSA ``should have attempted to quantify this 
risk'' and assessed why those disbenefits are reasonable to accept. The 
Alliance suggested that a false positive in FMVSS-compliant AEB 
vehicles could induce rear-end collisions with vehicles that are not 
equipped with rule-compliant AEB systems. The Alliance's petition 
included simulation data indicating that a vehicle complying with the 
final rule must respond within 0.35 seconds to avoid contact in one of 
the obstructed pedestrian crossing situations, which it argues is 
beyond the reaction ability of human drivers that may be behind these 
vehicles. It claimed that this discrepancy will likely result in a 
rear-end crash. Furthermore, according to the Alliance, increases in 
relative speed may heighten the likelihood of false positives due to 
the need for earlier prediction and intervention. The Alliance stated 
that NHTSA acknowledged that false positives could generate problems 
with public acceptance of AEB technology. It also stated that NHTSA 
dismissed this concern in the final rule without demonstrating that the 
final rule's requirements will not significantly impact the rate of 
false positives, and without understanding that the final rule demands 
effectively different systems from those currently installed in 
vehicles. The Alliance did not suggest any specific alternative.
    Toyota claimed that the requirements in the final rule will likely 
lead to an increase in false positives and can create driving behavior 
that neither the driver of the subject vehicle nor the drivers of 
surrounding vehicles will find natural or predictable, resulting in 
safety disbenefits. It stated that due to high maximum testable speeds, 
AEB will need to activate earlier to avoid a collision, and while a 
system can be designed to better account for curves in the road or 
parked cars, systems cannot be designed to predict what drivers in lead 
vehicles intend to do. Regarding PAEB, Volkswagen claimed that because 
pedestrians may change their travel path to avoid a collision 
themselves, AEB activations that initiate early to avoid a potential 
collision will result in rear end collisions with the stopping vehicle.
Agency Response
    Petitioners' statements were largely speculative. In support of 
these

[[Page 93204]]

arguments, they did not present any new data or analysis beyond what 
the agency had already considered.\18\ Petitioners have failed to 
provide data demonstrating the likelihood of an increase in false 
positives or the magnitude of the increase, nor is NHTSA aware of any 
source of such data.
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    \18\ Petitioner's simulation data provided regarding the 
obstructed pedestrian crossing test is discussed in Section G.
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    Under the Administrative Procedure Act (APA) and the Safety Act, 
NHTSA's obligation is not to eliminate uncertainty. Courts have 
repeatedly emphasized that the agency's job is to acknowledge 
uncertainty, explain the available evidence, and offer a ``rational 
connection between the facts found and the choice made.'' \19\ In 
coming to its determination, NHTSA dealt with each of the principal 
uncertainties and resolved them to the degree possible. In some cases, 
the requisite decisions were necessarily based on imperfect data and 
were inherently judgmental or predictive in part. The obligation to 
make such decisions and resolve such uncertainties is an integral part 
of NHTSA's mandate under the Safety Act and the APA. Our determination 
under the Safety Act, which was based on several factors including the 
available test data, was that collision avoidance was practicable and 
that any risk of increased false positives and rear collisions did not 
outweigh the benefits of the rule. Therefore, considering the data 
available and applying our expert judgment about the unquantifiable 
aspects of the rule, we selected the option that best meets the need 
for safety.
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    \19\ In Motor Vehicle Mfrs. Assn. of United States, Inc. v. 
State Farm Mut. Automobile Ins. Co., 463 U.S. 29, 51-52 (1983), the 
Court recognized that ``[i]t is not infrequent that the available 
data does not settle a regulatory issue and the agency must then 
exercise its judgment in moving from the facts and probabilities on 
the record to a policy conclusion. Recognizing that policymaking in 
a complex society must account for uncertainty, however, does not 
imply that it is sufficient for an agency to merely recite the terms 
`substantial uncertainty' as a justification for its actions.'' See 
also Public Citizen, Inc. v. NHTSA, 374 F.3d 1251, 1261-62 (D.C. 
Cir. 2004).
---------------------------------------------------------------------------

    NHTSA acknowledged the uncertainties and explained our reasoning 
throughout the rulemaking effort. In the FRIA, we noted that there is 
insufficient data to quantify the frequency and dynamics of false 
positive scenarios.\20\ We explained that the analysis had limitations 
regarding crash scenarios and parameters beyond those reflected in 
testing. We recognized from our testing that performance is variable 
and false positives do occur on current systems. However, this 
uncertainty, on its own, does not demonstrate that false positives 
would become more frequent under the final rule.
---------------------------------------------------------------------------

    \20\ Light Vehicle AEB FRIA, Docket No. NHTSA-2023-0021-1069, at 
252 (FRIA).
---------------------------------------------------------------------------

    We also explained that it is not possible to anticipate an 
exhaustive list of other possible real-world scenarios that systems 
would face and continually repeat testing to establish a robust 
estimate of the frequency of false positive occurrence. Based on this 
reasoning and test results, the analysis in the FRIA considered false 
positive rates to be the same under the final rule as they are in the 
current fleet. These false positives are therefore included in the 
analysis, but do not contribute to costs or benefits in the rule. The 
FRIA acknowledged that removing that assumption would reduce the 
magnitude of the estimated safety impacts. However, as the estimated 
benefits from the final rule are 17 to 21 times greater than the costs, 
it is unlikely that disbenefits from incremental false positives 
resulting in an increase in rear-end crashes would render the rule not 
cost-beneficial.
    Despite these limitations, we nonetheless considered the problem 
qualitatively and addressed it to the extent possible. We emphasized 
that because market penetration of AEB is very high, incremental 
disbenefits resulting from all applicable vehicles having rule-
compliant lead vehicle AEB would be insignificant.\21\ We also 
emphasized our belief that false positives would not occur in well-
designed AEB systems, especially with the integration of supplemental 
technologies. These technologies can include providing sufficient 
redundancy or continuously receiving and updating information regarding 
a vehicle or pedestrian as the vehicle approaches.
---------------------------------------------------------------------------

    \21\ FRIA at 252. Petitioners argue that this analysis is 
unconvincing because of the timeline of fleet turnover. However, the 
moment of 100 percent fleet adoption is not the only relevant 
timeline. Table 218 in the FRIA shows cumulative exposure by year. 
By year 6, we anticipate that 50 percent of the fleet will have 
rule-compliant AEB such that concerns about additional rear-ends 
derived from false activations will be significantly abated.
---------------------------------------------------------------------------

    Additionally, we did not simply disregard risks of false 
activations due to the speculative nature of the risks. We incorporated 
two false positive testing scenarios to establish a minimum level of 
system functionality in avoiding such events. We noted that, while 
certainly not comprehensive, we selected these scenarios because we 
believe they represent the most common scenarios systems will encounter 
and they address known engineering challenges for existing AEB 
systems.\22\
---------------------------------------------------------------------------

    \22\ 89 FR 39686, at 39732; FRIA at 47.
---------------------------------------------------------------------------

    Furthermore, we also emphasized many possible benefits from the 
rule that the analysis also could not quantify. These include safety 
benefits associated with crash scenarios and parameters outside of 
those reflected in agency testing, safety benefits from avoiding 
secondary crashes, safety benefits from preventing or mitigating 
crashes with other vulnerable road users or animals, and property 
damage and traffic congestion avoided.\23\
---------------------------------------------------------------------------

    \23\ FRIA at 47.
---------------------------------------------------------------------------

    In contrast, the petitioners simply asserted speculative 
disbenefits based on theoretical scenarios. The Alliance, for example, 
presented simulation data to support the possibility of rear-end 
collisions that could occur if a vehicle has a false positive with a 
human driver behind it, but it did not provide any evidence that the 
false positive events themselves would occur in greater frequency or 
severity under the final rule compared to no requirement or an 
alternative requirement.\24\ Additionally, Volkswagen asserts that ``no 
contact'' ``will undoubtably lead to higher false positive rates'' in 
scenarios in which a pedestrian changes their travel path following the 
onset of braking, and Toyota made a similar claim with regards to lead 
vehicle AEB.\25\ When considering the balance of costs and benefits, 
petitioners seek to place greater weight on speculative and 
unquantifiable disbenefits without considering the added benefits which 
may also be obtained. These assertions are insufficient to demonstrate 
that the speculative disbenefits outweigh the benefits of a no contact 
requirement. Without sufficient information to fully quantify either, 
it is not unreasonable for NHTSA, in its expert judgment and in 
consideration of the Safety Act's

[[Page 93205]]

focus on safety, to select the option that maximizes possible safety 
benefits.
---------------------------------------------------------------------------

    \24\ We also disagree with the petitioners' conclusions about 
these hypothetical scenarios. If the driver of the following vehicle 
maintains the safe distance required by law, a collision with the 
rule-compliant subject vehicle would not occur. Additionally, as we 
noted in the final rule, if an AEB activation of the subject vehicle 
leads to a collision with the following vehicle in a true positive 
situation, we believe that the AEB activation effectively reduces 
the likelihood of multiple collisions in a single crash. The AEB 
system would prevent the subject vehicle from colliding with an 
obstacle--whether another vehicle or a pedestrian--in its path.
    \25\ Nothing in the final rule prevents systems from relaxing 
braking once an imminent collision is no longer present or from 
designing AEB systems with algorithms that suppress AEB activations 
in certain circumstances such as after a substantial steering input 
or the application of additional throttle. However, when tested 
according to the procedures specified in the rule, the system must 
operate to avoid a collision.
---------------------------------------------------------------------------

b. Defect Authority
    The Alliance stated that it is insufficient for NHTSA to address 
false positives through the agency's safety defect authority. The 
Alliance stated that false positives are an unwanted side effect, 
similar to an issue experienced with early higher-powered airbag 
technology, which NHTSA needs to address through rulemaking to amend 
the performance requirements rather than through recalls. The Alliance 
argued that after the new FMVSS, ``[i]t is not sufficient, or fair,'' 
to continue to ``address `false positives' through [NHTSA's] safety 
defect authority.'' This argument primarily stemmed from the Alliance's 
claim that, due to current limitations in AEB technology, increasing 
the sensitivity of an AEB system to meet the performance requirements 
of the new FMVSS would increase the likelihood that the AEB system 
would also erroneously detect obstacles where none exist.
Agency Analysis
    The Alliance's arguments do not support reconsideration of the 
final rule for several reasons.
    First, the variability of false positive scenarios lends itself to 
the more individualized review of real-world operation that the defects 
process allows. As we noted, the final rule included two false 
activation test scenarios, but these are not comprehensive for 
eliminating susceptibility to false activations.\26\ The best forum for 
such an individualized review is NHTSA's defects authority, which can 
accommodate investigations that consider the reasonableness of the 
potential safety risks in light of all of the facts and circumstances. 
In contrast, an FMVSS sets a static performance requirement for all 
systems. Therefore, the defects authority is an appropriate avenue for 
addressing false positive events.
---------------------------------------------------------------------------

    \26\ 89 FR 39686, at 39732.
---------------------------------------------------------------------------

    Second, there is an established precedent of both NHTSA and 
manufacturers addressing false positive AEB events through safety 
recalls. In the past, vehicle manufacturers have filed recalls based on 
the safety risk that, for example, has been described as ``[i]f the AEB 
system unexpectedly activates while driving, the risk of a rear-end 
collision from a following vehicle may increase.'' \27\ Likewise, NHTSA 
has undertaken multiple defect investigations of potential safety risks 
arising from false activations of AEB systems.\28\ The public has 
similarly raised concerns about the safety risks associated with AEB 
false activations, requesting NHTSA apply its safety defect authority 
to the issue.\29\ This established practice demonstrates that using the 
defects authority to address false positives has been effective and 
workable, and the Alliance does not explain why it will not continue to 
be under the final rule.
---------------------------------------------------------------------------

    \27\ See, e.g., Tesla, Part 573 Safety Recall Report, No. 21V-
846, Unexpected Activation of Automatic Emergency Brake, available 
at https://static.nhtsa.gov/odi/rcl/2021/RCLRPT-21V846-7836.PDF.
    \28\ See, e.g., NHTSA, Opening Resume: Engineering Analysis EA 
24-002, Inadvertent Automatic Emergency Braking, available at 
https://static.nhtsa.gov/odi/inv/2024/INOA-EA24002-11766P1.pdf; 
NHTSA, Opening Resume: Preliminary Evaluation PE 24-008, Inadvertent 
Automatic Emergency Braking, available at https://static.nhtsa.gov/odi/inv/2024/INOA-PE24008-10868.pdf; NHTSA, Opening Resume: 
Preliminary Evaluation 24-013, Inadvertent Automatic Emergency 
Braking, available at https://static.nhtsa.gov/odi/inv/2024/INOA-PE24013-12241.pdf; NHTSA, Opening Resume: Preliminary Evaluation 23-
017, Inadvertent Automatic Emergency Braking, available at https://static.nhtsa.gov/odi/inv/2023/INOA-PE23017-10785.pdf.
    \29\ See, e.g., NHTSA, Opening Resume: DP 19-001, Defect 
Petition for False Automatic Emergency Braking, available at https://static.nhtsa.gov/odi/inv/2019/INOA-DP19001-5499.PDF. NHTSA also 
often receives customer complaints regarding the issue through 
Vehicle Owner Questionnaire submissions.
---------------------------------------------------------------------------

    Third, the Alliance's petition suggests that current technical 
limits in AEB equipment, such as sensor range or definition, would make 
it unfair for NHTSA to act on safety risks that were a byproduct of 
manufacturer efforts to meet the performance requirements of the new 
FMVSS. However, in striving to protect the public, the Safety Act 
requires manufacturers to remedy all unreasonable safety risks in their 
vehicles, regardless of the reason for their origin. A manufacturer's 
good intention is not a defense to a recall.\30\
---------------------------------------------------------------------------

    \30\ See 49 U.S.C. 30116 et seq.; 49 U.S.C. 30102; see also 49 
U.S.C. 30118 (establishing that general recall notification 
responsibilities apply to all defects and is not based on design 
intent).
---------------------------------------------------------------------------

    Fourth, the false positive risks that petitioners raise are 
speculative. No petitioner or commenter has identified an aspect of the 
new FMVSS that will cause future defects related to false positives. At 
most, the Alliance has identified challenges with existing AEB 
technology that could lead some manufacturers to inadvertently be 
imprecise or overinclusive when calibrating the sensitivity of their 
AEB systems to meet the new FMVSS. The Alliance has not suggested that 
these errors in implementation would be impossible to eliminate or 
mitigate once they became apparent.
    Finally, the Alliance's example of early, ``high-powered'' air bags 
is an inapt analogy. Early versions of air bags deployed with a fixed 
amount of force that posed a risk of injury to occupants. These risks 
were not an occasional byproduct of those air bags but were inherent to 
the forces generated when those air bags deployed as quickly as needed 
to meet the performance requirements of the original air bag FMVSS. As 
air bag technology improved, air bags became capable of modulating the 
force of their deployment to limit the injurious potential of their 
inflation. When updating the FMVSS to require advanced air bags, NHTSA 
noted that ``the fact that we are requiring manufacturers to provide 
improved air bags in new vehicles does not mean that earlier vehicles 
that do not meet the new requirements have a safety-related defect.'' 
\31\ By contrast, an AEB false positive (such as braking in the absence 
of a true obstacle) is not a behavior required by the final rule. 
Rather, it is at most an accidental engineering failure from trying to 
design an AEB system with sufficient sensitivity to meet the 
performance standard. In fact, AEB false positives are more like the 
safety defects posed by air bag inflator ruptures. These occur when, in 
an effort to design air bag systems capable of meeting the intense 
inflation demands of the FMVSS, engineering failures cause ruptures 
which project debris. In the same way, even assuming the Alliance is 
correct that the performance demands of the final rule may sometimes 
result in faulty AEB system designs that are susceptible to false 
positives, those false positives are a failure in the implementation of 
the AEB system, not an inherent performance characteristic of the 
standard.
---------------------------------------------------------------------------

    \31\ 65 FR 30680, 30705 (May 12, 2000). The same approach is 
true for FMVSS No. 127: the fact that vehicles manufactured before 
the new FMVSS takes affect may have AEB systems that do not meet the 
new standards (or perhaps do not have AEB at all) does not mean 
those earlier vehicles have safety-related defects simply because 
they do not meet the new standards.
---------------------------------------------------------------------------

    For these reasons, no reconsideration is needed on this issue.
c. Comparison to a Standard That Allows Low-Speed Contact
    To address false positive risks and practicability concerns, 
Volkswagen and Toyota petitioned for the consideration of allowing a 
low-speed contact, such as up to 10 km/h (6.2 mph).\32\ They present 
two justifications. First, they make a novel assertion, not raised 
during the NPRM comment period, that NHTSA implicitly accepts contacts 
under 10 km/h because the final rule does not

[[Page 93206]]

require AEB systems to operate at speeds 10 km/h and below. Second, 
Toyota claims that NHTSA's analysis did not establish how no contact 
meets the need for safety in comparison to low-speed contact 
alternatives.\33\
---------------------------------------------------------------------------

    \32\ Hyundai also discussed this issue in its letter.
    \33\ Hyundai, in its letter, argued that a 10 km/h minimum 
allowable collision speed would preserve the safety benefits of the 
rule because contacts under that speed are unlikely to result in 
serious injuries or fatalities. One comment discussed in the final 
rule stated similarly. 89 FR 39686, 39272.
---------------------------------------------------------------------------

Agency Analysis
    Petitioners' arguments do not support reconsideration of the final 
rule. As an initial matter, NHTSA's analysis fully considered this 
issue and the relevant alternatives in the rulemaking. In the NPRM, we 
sought comment on alternatives to the no contact requirement, 
specifically regarding allowing low-speed contact in on-track testing 
for both PAEB and lead vehicle. We received extensive comment both in 
support of and against allowing contact at low speeds. In the final 
rule, the agency disagreed that a low-speed approach fully resolved the 
safety problem, emphasizing that no contact provides maximum safety 
benefits and aligns with the Safety Act. We reiterated that striking a 
person with a vehicle is unacceptable at any speed under any 
conditions, and the analysis in our FRIA supports that conclusion. We 
believe the data and analysis in the final rule and the FRIA 
demonstrate the safety basis upon which ``no contact'' was selected 
over low-speed alternatives. Therefore, we are not amending the final 
rule on these bases. However, as petitioners have presented a new 
framing of the argument regarding the 10 km/h (6.2 mph) activation 
threshold, we take this opportunity to highlight the data and analysis 
that supports the final rule to respond to the points raised by 
petitioners.
    Petitioners present a false equivalency between the activation 
threshold and contact speeds. Activation of an AEB system while moving 
below 10 km/h is a different scenario from continuing to move at up to 
10 km/h after an activation has already occurred. The impact speed is 
part of the in-operation performance of the system. That is, once an 
AEB system detects an imminent collision with a vehicle or pedestrian, 
we anticipate that the systems will remain active as long as the 
imminent collision risk persists. The AEB minimum activation speed, on 
the other hand, is selected as a design specification. Petitioners 
attempted to conflate these circumstances, which is unpersuasive.
    Additionally, the activation threshold exists to ensure 
practicability, not because no safety concerns exist below that 
speed.\34\ When discussing PAEB testing in the NPRM, for example, we 
noted that the lower bound was chosen based on a tentative conclusion, 
corroborated by our 2020 testing and testing on vehicles from model 
years 2021 and 2022, that PAEB systems may not offer consistent 
performance at speeds below 16 km/h (9.9 mph) and that 10 km/h (6.2 
mph) is consistent with Euro NCAP's testing lower bound.
---------------------------------------------------------------------------

    \34\ We have been consistent in our belief that collisions under 
10 km/h present a safety risk. In the NPRM, we noted that ``not 
requiring PAEB to be active below 10 km/h (6.2 mph) should not be 
construed to preclude making the AEB system active, if possible, at 
speeds below 10 km/h (6.2 mph). In fact, the agency anticipates that 
manufacturers will make the system available at the lowest 
practicable speed.'' 88 FR 38632, at 38667.
---------------------------------------------------------------------------

    In addition to those stated in prior notices, there are several 
other reasons for the practicability concerns that justify a 
distinction between 10 km/h as an activation threshold and as a maximum 
contact speed in testing. First, at speeds below 10 km/h, the driver 
has more time to re-engage and apply the brakes to avoid the collision 
without AEB intervention. Second, AEB systems can have difficulty 
operating in very tight spaces and at low speeds such as in crowded 
parking garages, where manoeuvres at low speed may need to occur in 
crash-imminent scenarios. Third, certain vehicles to which the 
regulation applies may need to push objects while operating at low 
speeds. Finally, our testing and data collection showed both that no 
systems operated at speeds under 5 km/h (3.1 mph), and that some 
vehicles that performed well in high-speed testing did not operate 
under 10 km/h (6.2 mph).\35\ These data suggest design challenges 
specific to low-speed operation. NHTSA considered these factors and 
determined that it was practicable to require only that systems operate 
above 10 km/h. Therefore, the activation threshold and whether to allow 
an impact speed have distinct considerations that justify different 
approaches.
---------------------------------------------------------------------------

    \35\ NHTSA-2023-0021-0005, Table 3.
---------------------------------------------------------------------------

    Furthermore, no contact better meets the need for safety in 
comparison to a regulation that allows low-speed contact. The data and 
analysis in the FRIA show that allowing for contact, at any speed, 
results in less safety benefits than are achieved by the final rule. In 
analyzing the capabilities of AEB technology, at least one vehicle 
tested was able to meet the no contact requirement in each scenario. 
Therefore, the benefits in the FRIA represent the level of safety 
associated with the best performer.\36\ The injury risk curves in the 
FRIA represent the likelihood of injury based on impact speed. In 
general, the likelihood of injury, and more severe injuries or 
fatalities, increases with respect to contact speed. And, although 
there are limits to the precision of the conclusion that can be drawn 
due to data limitations, the injury risk curves show that allowing for 
contact at any speed results in less safety benefits than are achieved 
by the best performer. NHTSA's analysis therefore fully considered this 
issue.
---------------------------------------------------------------------------

    \36\ This ties the benefits calculations directly to a vehicle's 
observed test performance. In contrast, fully calculating the 
benefits of a standard that allowed contact would require adjusting 
the best performer away from the test data. This would involve 
assumptions about best performance under the rule that are not tied 
to observed performance and reduce the accuracy of the benefits 
calculations.
---------------------------------------------------------------------------

    The PAEB data clearly show that a low-speed contact alternative 
would achieve substantially less safety than no contact.\37\ Even at 
the lowest impact speeds of 0-5 mph, there is a 75 percent chance of 
minor injury, 4 percent chance of a moderate severity injury, and a 1 
percent chance serious injury or worse. Furthermore, at even the next 
impact speed group, there is a non-zero probability of a fatality.\38\ 
NHTSA considered these risks in deciding that no contact in PAEB 
testing meets the need for safety.
---------------------------------------------------------------------------

    \37\ Injury risk data used in this paragraph is presented in the 
FRIA, Table 131. The table and this data are rounded to the nearest 
hundredth. The true figures are as follows: at a maximum contact 
speed of 5 mph, approximately 0.4 percent of collisions would result 
in fatality, 75 percent would result in minor injury, 4 percent in 
moderate injury, and 0.7 percent in serious injury. These 
descriptions correspond to the maximum abbreviated injury scale 
(MAIS) categories, described on pages 238-239 of the FRIA. Minor 
injuries can include non-superficial injuries, including those with 
long term effects such as whiplash, and moderate injuries include a 
fractured sternum.
    \38\ Petitioners suggested allowing contact at up to 10 km/h, 
which would correspond to a roughly 6 mph impact speed. The data in 
the FRIA is organized by miles-per-hour, so for this response we 
discussed injuries in the impact speed range closest to but below 
this figure, which is 0-5 mph.
---------------------------------------------------------------------------

    By applying these percentages to the PAEB data across the injury 
severity categories in the estimated benefits of the final rule, we 
find significant benefits to a no contact standard.\39\

[[Page 93207]]

Allowing contact at low speeds would lead to 2,192 additional minor 
injuries, 31 moderate injuries, 3 serious injuries, and 1 fatality 
annually. Monetized, this change results in $179.1 million 
comprehensive economic benefits lost, or 4.9 percent of the PAEB 
benefits generated by the final rule.\40\ This is a sizable impact, and 
one that NHTSA considers meaningful. Indeed, $179.1 million of 
comprehensive economic benefits is larger than those of many entire 
safety rules we issue.
---------------------------------------------------------------------------

    \39\ Although this discussion is new analysis in response to the 
petitions for reconsideration, we note that this analysis uses only 
data already in the FRIA and uses no proprietary statistical 
methods. In the FRIA, PAEB is considered in crossing path and along 
path scenarios. For along path scenarios, we assume that all 
pedestrian impacts would be avoided under a no contact requirement, 
so allowing contact would distribute those incidents that would have 
been avoided across each injury severity category by the percentage 
of injuries associated with each severity at the selected contact 
speed. For crossing path scenarios, even under a no contact 
requirement there are situations in which pedestrians enter the path 
of the vehicle with insufficient time for detection and braking to 
avoid the collision. Therefore, the expected effect of allowing 
contact should account for a reduced number of both avoided and 
mitigated injuries.
    \40\ Performing the same analysis as used in this paragraph on 
contacts up to 10 mph yields additional lost benefits of only 0.7 
percent. This result suggests that most of the safety benefits lost 
from a low-speed contact option are lost in the contact allowance.
---------------------------------------------------------------------------

    For lead vehicle AEB, the low-speed injury data in the FRIA has 
more limitations than that for PAEB. The relatively small number of 
severe injuries that occur in rear-end collisions at low speeds 
compared to those that occur in high speed collisions causes 
implausible analytical results that limit the precision of the 
conclusions that can be drawn about the exact level of safety benefit 
obtained at low impact speeds. Nonetheless, the available data 
demonstrate that benefits would be lost with a contact standard and the 
general magnitude of those lost benefits.
    The injury data in the FRIA show that allowing contact at any speed 
reduces the safety benefits.\41\ At a relative contact speed of 10 mph 
(the difference between striking vehicle speed and struck vehicle 
speed), the probability of minor injury increases to 21.9 percent, 
moderate injuries to 0.9 percent, serious injuries to 0.7 percent, and 
even 0.1 percent chance of a fatality. In fact, even at a relative 
contact speed of just 1 mph (contact at 2 mph), there is a 3.5 percent 
chance of minor injury and a 0.4 percent chance each of moderate and 
serious injuries. The FRIA contains an example calculation to show how 
these figures are derived and factor into NHTSA's benefits 
analysis.\42\
---------------------------------------------------------------------------

    \41\ FRIA, Table 108.
    \42\ FRIA at 761 (the example begins on p. 763). Note that it 
appears some of the values in FRIA Table 317, which summarizes input 
parameters, appear to be incorrect. Table 317 stated that the TTC 
Duration(s) were 2.01 for each FCW scenario. The correct values are 
as follows: Status quo (SQ) Lead Vehicle Stopped (LVS) of 2.01, SQ 
Lead Vehicle Moving (LVM) of 2.09, SQ Lead Vehicle Decelerating 
(LVD) of 2.14, Best performer (BP) LVS of 2.06, BP LVM of 2.12, and 
BP LVD of 2.23.
---------------------------------------------------------------------------

    The data and analysis in the FRIA show that while low-speed 
collisions are less likely to result in severe or fatal injuries, 
reducing the number of injuries that are less severe can carry large 
safety benefits due to the large volume of those injuries. As the final 
rule states, between 2016 and 2019, there were an average of 1.75 
million rear-end crashes annually (and nearly 55,000 frontal crashes 
with a pedestrian). Even small changes in injury risk can have sizable 
impacts across that volume of collisions.\43\ Additionally, even 
injuries classified as less severe in the data cause serious harm, and 
these injuries, such as whiplash, can carry long-term effects. In the 
final rule, the agency concluded that although the data is limited, it 
plainly indicates that a no contact standard achieves greater safety 
benefits than a standard that allows contact.
---------------------------------------------------------------------------

    \43\ FRIA, Tables 225 and 251. Note that these crash estimates 
were not used to estimate benefits. The target population used to 
estimate benefits for lead vehicle AEB and PAEB included several 
filters to best reflect the real-world crashes that corresponded 
with the test scenarios and conditions.
---------------------------------------------------------------------------

    In contrast to the data collection and analyses done by NHTSA, 
petitioners suggest that NHTSA should prioritize speculative 
disbenefits from false positives over the demonstrable safety benefits 
that a no contact requirement achieves. Petitioners did not provide any 
new information or data that was not already considered by the agency 
during the development of the final rule in response to public comments 
suggesting that a low-speed alternative would better meet the need for 
safety. Nor did they provide, at any stage in the rulemaking, 
compelling information regarding the increase in false positives that 
they fear or evidence that a no contact requirement will result in such 
an increase while allowing a 10 km/h (6.2 mph) contact speed would not. 
Although we recognized that there are unquantifiable aspects, NHTSA was 
well within its responsibilities to consider this risk but to weight 
more heavily the demonstrable safety benefits achievable by a no 
contact requirement. The Safety Act entrusts NHTSA with this 
responsibility and to exercise its judgment, and we did so. Therefore, 
no reconsideration is necessary, and we deny the request for 
reconsideration to allow low-speed contact.

B. Multiple Trials

    The final rule requires that the test vehicle meet the performance 
test requirements in any test run and does not allow multiple test runs 
in which the vehicle is only required to meet the required performance 
in a percentage of the runs. Petitioners requested that the standard be 
amended to incorporate multiple test runs to allow a vehicle to meet 
the performance requirement in some but not all runs, and provided 
several reasons discussed below.
1. Comparison to FMVSS No. 135 and Forms of Variability
    Petitioners argued that the final rule did not account for the 
variabilities in testing. They requested FMVSS No. 127 be amended to be 
similar to FMVSS No. 135, which allows for compliance to be determined 
based on multiple test runs. Petitioners suggested several variations, 
including passing 5 out of 7 runs (which is similar to NCAP), passing 3 
out of 5 runs, and a requirement that if the vehicle fails the first 
run it must pass three subsequent runs.\44\
---------------------------------------------------------------------------

    \44\ The Alliance also noted that, if NHTSA provides sufficient 
relief regarding the no contact requirement, then this relief may 
not be necessary.
---------------------------------------------------------------------------

    The Alliance stated that existing braking standards, specifically 
FMVSS No. 135, acknowledge the inherent variability in vehicle braking 
systems that make it unreasonable to evaluate performance based on a 
single test run. The Alliance suggested that since AEB is a braking 
system, it has these variations, which raise practicability concerns 
when a test requirement does not allow for multiple test trials. These 
variations derive from both foundational braking mechanisms and 
additional variability from sensing and perception responses. 
Therefore, the Alliance argued that NHTSA failed to recognize that 
FMVSS No. 127 deviates from its established practice of permitting 
multiple test runs for braking standards. Moreover, it claims that 
NHTSA did not provide any explanation in the final rule for departing 
from this longstanding precedent.
Agency Analysis
    NHTSA received comment on and fully considered the issue of 
multiple trials during the rulemaking. The arguments raised in the 
petitions do not justify allowing multiple test trials.
    That multiple test runs are used in FMVSS No. 135 does not mean 
that multiple test runs are necessary for FMSS No. 127. There is a 
critical difference between FMVSS No. 135 and FMVSS No. 127 that 
justifies a different approach.\45\ The purpose of FMVSS No.

[[Page 93208]]

135 is to ensure safe braking performance, and its testing is designed 
to test braking performance of the vehicle.\46\ It uses multiple test 
runs to account for the variability in the ability of the human test 
driver to maximize the braking capabilities of the vehicle. The agency 
published the first NPRM for what would become FMVSS No. 135 in 1985. 
In that NPRM, the agency stated that ``[t]he purpose of specifying 
multiple stops is to enable test drivers to achieve a vehicle's best 
performance.'' \47\ That preamble further stated that it normally took 
test drivers three or four stops to achieve the best possible braking 
performance. NHTSA has also rejected incorporation of multiple test 
runs into the standard for the ``hot stop'' test because NHTSA found in 
its testing that the human test drivers were capable of achieving the 
needed performance for the test, and the test needed to occur while the 
brakes were at temperature.\48\ Additionally, in FMVSS No. 126, an 
example of a standard where NHTSA found a single test run to be 
sufficient, the sine-with-dwell test provides for only one test run at 
each steering-wheel amplitude and rotation direction combination. 
Further, in the final rule establishing FMVSS No. 136, ``Electronic 
stability control systems for heavy vehicles,'' NHTSA stated that FMVSS 
No. 136 allows multiple attempts to maintain the lane for J-turn 
testing to ensure that the ESC system activates before the vehicle 
becomes unstable instead of imposing a requirement that it activate 
prior to instability to ``account for driver variability and possible 
driver error in conducting the manoeuvre. Absent driver error, we do 
not expect any vehicle equipped with current-generation ESC systems to 
leave the lane during any J-turn test.'' \49\ These examples make clear 
that a standard that permits multiple test trials is justified where 
testing may be affected by variability in a human test driver's ability 
to apply a full brake application. It may be the case that, because it 
allows multiple test trials to accommodate human test drivers, FMVSS 
No. 135 accommodates the other forms of test variability cited by 
petitioners. However, this result is an ancillary effect of the 
standard's design, not its purpose.
---------------------------------------------------------------------------

    \45\ Not all the tests in FMVSS No. 135 use multiple trials. 
Those that do include: S7.5. Cold effectiveness; S7.6. High speed 
effectiveness, S7.7. Stops with Engine Off, S7.8. Antilock 
functional failure, S7.9. Variable brake proportioning system 
functional failure, and S7.11. Brake power unit or brake power 
assist unit inoperative (System depleted). These afford up to six 
test runs to achieve the required performance.
    \46\ 49 CFR 571.135, S2.
    \47\ 50 FR 19751.
    \48\ 60 FR 6431.
    \49\ 80 FR 36050.
---------------------------------------------------------------------------

    In contrast to FMVSS No. 135, the test procedures in FMVSS No. 127 
test the AEB system and do not use human test drivers to actuate the 
brakes. Even for tests that include manual brake application, the test 
procedure specifies use of a braking robot and the performance 
specifications on how the brake must be actuated for the test. No 
variability from human operation contributes to test outcomes in FMVSS 
No. 127.
    Indeed, the Alliance, in attempting to argue that FMVSS No. 135 
test results are not informative of AEB system performance, 
acknowledged this distinction is meaningful. It claimed that test 
conditions in FMVSS No.'s 135 and 127 ``are fundamentally different 
such that FMVSS No. 135 results are not indicative of AEB performance'' 
because tests conducted under FMVSS No. 135 are ``conducted with a 
human driver putting muscular effort into the brake pedal.'' \50\ This 
distinction justifies NHTSA's decision not to use multiple test runs.
---------------------------------------------------------------------------

    \50\ In making this argument, the Alliance is suggesting that 
NHTSA cannot rely on FMVSS No. 135 tests to show the practicability 
of the no contact requirement because these tests will have superior 
braking performance to FMVSS No. 127 tests due to added muscular 
effort from the driver. This claim is discussed in the ``no 
contact'' section, above.
---------------------------------------------------------------------------

a. Specific Forms of Variability Raised by Petitioners
    Petitioners cited several forms of variability that they argue 
justify multiple test runs or render the standard impracticably 
stringent. The Alliance, for example, cited wear and tear of pedestrian 
test dummies, design of pedestrian test dummies, and headlamp aim as 
aspects specific to AEB system performance that can impact testing. It 
also emphasized track conditions that contribute to stopping distance 
variability, such as the age and degradation of the asphalt since it 
was last resurfaced, the type of aggregate used on the test track, and 
other variables. The Alliance also noted that compliance tests are 
conducted at any number of test tracks throughout the United States, 
which the Alliance claimed further amplifies variability of the test by 
contributing their own unique characteristics. It also noted ambient 
environmental effects such as cloud cover (or intermittent cloud 
cover), dust, debris, pollen effects, recent rainfall, and noise 
factors. It also stated that the road surface friction decreases as the 
road surface temperature increases, and provided a figure that shows 
road surface friction around 0.98 at a temperature of 2 degrees C and 
decreasing to around 0.92 at 50 degrees C, and that these variations in 
ambient conditions can translate into about 8-10 feet (2.5-3m) or more 
variation in absolute stopping distance on a given test surface. It 
also raised vehicle conditions, such as tire burnish, brake burnish, 
brake wear and brake bleed, which amplify these environmental effects. 
The Alliance stated that these factors (ambient conditions, vehicle 
conditions, and track conditions) support the reason why FMVSS No. 135 
accommodates outcome variability by using multiple trials, justify 
using multiple trials, or justify a change in the no contact 
requirement.
    The Alliance stated that NHTSA's data demonstrate the challenges of 
avoiding contact in every test that result from their cited 
variability. The Alliance emphasized that no test scenario showed that 
all tested vehicles could meet the performance requirements for lead 
vehicle AEB on every test run. Starting at 64 km/h (40 mph), fewer than 
half of the tested vehicle met the performance requirements in all the 
test trials. The Alliance further stated that, while the research 
conducted tests only up to 72 km/h (45 mph), at which only two models 
avoided contact, the standard requires compliance with lead vehicle AEB 
test at speeds up to 100 km/h (62 mph) without demonstrating the 
feasibility and practicability at those higher speeds. It also 
referenced PAEB testing, for which at the lowest tested speed (16 km/h 
(9.9 mph)), vehicles failed in over 25 percent of the test runs. At 
speeds of 65 km/h (40.4 mph) in dark conditions, the Alliance stated 
that no tested vehicle could comply with the requirements 100 percent 
of the time. The Alliance reasoned, therefore, that NHTSA's test data 
indicates that most vehicles do not meet the standard's requirements, 
and the agency has not provided any analysis demonstrating why these 
data or other information prove the practicability of avoiding contact 
on every test run.
Agency Analysis
    NHTSA disagrees that the types of variability raised by petitioners 
make the rule impracticable or justify multiple test runs.
    First, several of these types of variability would not be resolved 
if FMVSS No. 127 allowed multiple test runs. For example, test track 
conditions, headlamp aim, and the differences between the pedestrian 
test device and real pedestrians, which do contribute to variability in 
AEB system performance, do not contribute to variability in performance 
across multiple test runs in the same place with the same test devices. 
The test track is relatively consistent across runs. Differences in the 
pedestrian test device and a real pedestrian may contribute to variable

[[Page 93209]]

performance between the real world and the test track, but it does not 
contribute to variability across multiple runs with the same test 
device. Therefore, allowing multiple runs would not resolve these 
concerns.
    Additionally, other variabilities raised by petitioners are 
resolved by other aspects of the FMVSS. The test conditions, including 
temperature range, are generally consistent with those of existing 
FMVSSs, such as FMVSS No. 135, which have proven effective over time in 
resolving many issues raised by petitioners, such as concerns with 
thermal effects on the surface friction of the test track. 
Additionally, the test procedures state that headlamps will be aimed 
per manufacturers' instructions and that testing will not occur during 
periods of precipitation or when visibility is affected by fog, smoke, 
ash, or particulates, which resolves many concerns regarding AEB system 
performance variability.\51\ The Alliance's concerns about the test 
dummies are also unfounded. Dummy wear and tear will not contribute to 
test performance variability because the test procedures specify the 
conditions for the test devices used.
---------------------------------------------------------------------------

    \51\ The Alliance also petitioned for more specificity regarding 
``visibility'' in the test condition. We provided a thorough 
discussion of this requirement and the reasons for not providing 
additional specificity in the NPRM and final rule.
---------------------------------------------------------------------------

    The Alliance's discussion regarding vehicle and test track 
variability is not persuasive because it relies on studies conducted 
with test vehicles not specifically designed to meet the requirements 
of the final rule. We anticipate the variability between vehicles 
designed to comply with an FMVSS will be relatively small and will 
depend on the compliance margins set by manufacturers according to 
their risk acceptance strategies.
    Regarding petitioners' claims that the current state of AEB 
technology means that multiple test runs are necessary for the standard 
to be practicable, we note that in the agency's 2023 research one 
tested vehicle was able to avoid contact on most runs, which marked 
significant progress compared to the 2020 testing. This and other 
improvements in AEB technology over time support the conclusions made 
in the final rule that these requirements are practicable within the 
allowed lead time. Under the Safety Act, the agency is empowered to 
issue safety standards that require advancements in existing technology 
or require development of new technology.\52\ Given the developmental 
trajectory, the agency does not find arguments based around the 
performance of existing AEB systems to be a persuasive argument for 
multiple trials.
---------------------------------------------------------------------------

    \52\ Chrysler, supra footnote 9.
---------------------------------------------------------------------------

b. System Maturity
    The Alliance stated that the final rule claimed that multiple 
trials are not necessary for mature systems. It argued that NHTSA 
incorrectly assumed that AEB technologies are mature, in part because 
AEB systems introduced under the 2016 voluntary commitment were not 
designed to meet the performance requirements of the final rule. The 
Alliance also referenced the FRIA--which stated that because many AEB 
systems do not meet the rule's requirements there will be significant 
benefits to the new rule-compliant AEB systems--to argue that the 
agency cannot consider an existing AEB system installed under the 2016 
commitment to be mature while simultaneously claiming significant 
benefits from the new systems required by the final rule. The Alliance 
also stated that rule-compliant AEB systems should be considered new or 
in development. It concluded that therefore these systems are not 
mature and should be allowed to demonstrate compliance through multiple 
test trials.
Agency Analysis
    NHTSA is unpersuaded by the Alliance's reframing of the issue. The 
fact that a current system can meet the requirements of the standard 
shows that the technology is mature--vehicles on the road today have 
the requisite technology to comply with the rule. The benefits 
estimates assess the improvements in outcomes generated when the entire 
fleet becomes compliant in comparison to the status quo baseline. As we 
explained in the FRIA, the status quo baseline is the average 
performance of the vehicles included in NHTSA's testing. Therefore, the 
benefits claimed are representative of mature systems being required 
throughout the fleet.
    Therefore, no reconsideration is needed. NHTSA denies the petitions 
for reconsideration regarding multiple trials and will not adjust the 
final rule to incorporate multiple test trials.

C. Equipment Requirement

    The final rule includes an equipment requirement that light 
vehicles have an AEB system that applies the brakes automatically at 
any forward speed that is greater than 10 km/h (6.2 mph) and less than 
145 km/h (90.1 mph) when a collision with a lead vehicle is imminent, 
and at any forward speed greater than 10 km/h (6.2 mph) and less than 
73 km/h (45.3 mph) when a collision with a pedestrian is imminent. It 
also includes a performance test requirement that, when tested 
according to the procedures in the rule, the subject vehicle provides a 
forward collision warning and subsequently applies the service brakes 
automatically when a collision with a lead vehicle is imminent such 
that the subject vehicle does not collide with the lead vehicle.
    The Alliance stated that the final rule lacks objectivity because 
NHTSA has not established performance requirements for the equipment 
required by final rule. It notes that while the rule requires the lead 
vehicle AEB and PAEB systems to operate at speeds up to 145 km/h (90.1 
mph) and 73 km/h (45.3 mph) respectively, it does not define the term 
``operate,'' Additionally, the Alliance argues, although the preamble 
to the final rule indicated that the systems would apply brakes when a 
collision is imminent, NHTSA did not define an imminent crash. To 
address these concerns, the Alliance requested a supplemental notice of 
proposed rulemaking (SNPRM) proposing objective performance 
requirements, including specifying what it means to ``operate'' the 
equipment and defining when a crash is ``imminent.''
Agency Analysis
    NHTSA is not incorporating definitions for ``operate'' or 
``imminent'' and is not incorporating a test procedure. However, NHTSA 
is making one clarifying edit to remove reference to ``imminent'' in 
the performance test requirement for lead vehicle AEB.
    NHTSA does not believe that it is necessary to provide a definition 
of or test procedures for the term ``operate'' in the regulatory text 
because the final rule's definition of AEB clarifies how an AEB system 
operates. FMVSS No. 127 defines ``Automatic Emergency Braking'' as ``a 
system that detects an imminent collision with vehicles, objects, and 
road users in or near the path of a vehicle and automatically controls 
the vehicle's service brakes to avoid or mitigate the collision.'' The 
definition of FCW provides similar clarity regarding FCW operation. 
Additionally, the requirement that these systems ``operate'' is 
explicitly tied to the test conditions in S6, Test Conditions, of FMVSS 
No. 127. In considering the meaning of ``operate'' in the context of 
the performance requirements applicable to AEB systems, the final rule 
provides sufficient clarity that manufacturers can certify with 
reasonable care that their systems ``operate'' in the circumstances

[[Page 93210]]

required by the final rule. Therefore, no definition is needed.
    Regarding the definition of ``imminent'' as used in the equipment 
requirements, no regulatory definition is needed. Certainly, not all of 
the terms in a regulation must be explicitly defined. Here, the term 
``imminent'' comes from the regulatory mandate in BIL.\53\ In BIL, 
Congress chose not to define the term, and we interpret this provision 
of BIL to use the plain meaning of the word ``imminent.'' \54\ 
Manufacturers may refer to the plain meaning when certifying their 
vehicles to the equipment requirements.\55\ Additionally, the term is 
sufficiently clear in context, and its meaning is discernable from 
close review of the performance requirements and test procedures in the 
rule, such as the set of testable ranges specified.
---------------------------------------------------------------------------

    \53\ 49 U.S.C. 30129 note.
    \54\ Miriam-Webster defines ``imminent'' as ``ready to take 
place; happening soon.'' https://www.merriam-webster.com/dictionary/imminent?utm_campaign=sd&utm_medium=serp&utm_source=jsonld (accessed 
on 8/28/24). For an analogous determination, see 81 FR 85478, 
Vehicle Defect Reporting Requirements. In this NPRM, we specified a 
location that is ``accessible'' for an information label pursuant to 
the section 31306 of the Moving Ahead for Progress in the 21st 
Century Act. We noted that while the statute did not explicitly 
require us or the manufacturer to determine the location, selecting 
a standardized location would best serve the purpose of the statute 
by facilitating repeated consumer access to the information. We also 
referenced the dictionary definition of the term ``accessible.''
    \55\ See, e.g., Ard v. O'Malley, 110 F.4th 613, 617 (4th Cir. 
2024).
---------------------------------------------------------------------------

    However, we are making a clarifying change to the performance test 
requirement. In its petition, the Alliance appears to conflate 
equipment requirements and performance requirements. The final rule and 
NPRM distinguished between them and explained how the equipment 
requirement supplements the performance requirement.\56\ The equipment 
requirement, explicitly mandated in BIL, does not have an associated 
performance test and compliance with it is not evaluated based on 
performance testing. On the other hand, compliance with the performance 
requirements is evaluated through the performance testing laid out in 
the final rule. Critically, these tests do not evaluate the activation 
timing of the AEB or FCW systems (other than that FCW should not 
activate after AEB). Rather, the performance criterion is contact with 
the test device (for AEB) and whether FCW activated. We therefore left 
to manufacturers the discretion to determine when to apply the brakes 
and provide the FCW, so long as their determination is not clearly 
erroneous.
---------------------------------------------------------------------------

    \56\ 88 FR at 36832, at 38655; see also 72 FR 17235, 17299 (Apr. 
6, 2007) (discussing the understeer requirement in FMVSS No. 126). 
The NPRM also explained how we might approach information gathering 
and enforcement of this requirement. The final rule also discussed 
NHTSA's authorities regarding equipment requirements in response to 
comment regarding activation speed. 89 FR 39686, 39712-14.
---------------------------------------------------------------------------

    To resolve any confusion, we are amending the performance test 
requirement for lead vehicle AEB in S5.1.3 to remove the phrase ``when 
a collision with a lead vehicle is imminent.'' The purpose of this 
change is to clarify the distinction between the performance 
requirements and equipment requirements in FMVSS No. 127 and does not 
substantively alter the requirements as described in the preamble. In 
fact, because NHTSA's testing will not evaluate AEB and FCW timing, and 
the test scenarios themselves create crash-imminent scenarios, this 
language was superfluous in the performance test requirement. This 
change also aligns the text of S5.1.3 with the performance test 
criteria for PAEB (S5.2.3), which does not contain that phrase. 
Although the preamble of the final rule explained this approach, the 
change discussed here makes it clear in the regulatory text. Finally, 
following the change, the term ``imminent'' only remains in the 
equipment requirement. Therefore, no performance test procedure is 
needed to evaluate compliance.
    Therefore, we are amending FMVSS No. 127 to resolve confusion in 
the requirements. However, we are denying the petitions for 
reconsideration regarding issuing an SNPRM to establish a test 
procedure for equipment requirements or providing a definition for 
``operate'' and ``imminent.''

D. Unlimited Preconditioning and Test Runs

    The final rule does not explicitly place a limit on the amount of 
pretest driving a vehicle may undergo and it does not place a maximum 
limit on the number of test runs a vehicle may be put through.\57\
---------------------------------------------------------------------------

    \57\ Specifically, test procedures state that prior to the test 
the subject vehicle is driven at any speed, in any direction, on any 
road surface, for any amount of time.
---------------------------------------------------------------------------

    The Alliance requested reconsideration, arguing that unlimited 
pretest driving of a subject vehicle is inconsistent with repeatable, 
objective test procedures. It also argued that the agency could accrue 
thousands of miles on the test vehicle, degrading the tires and other 
wear components, before running the compliance test. Petitioners 
expressed concern that manufacturers would have no way to predict what 
the agency's pretest driving scenarios will do to the subject vehicle, 
making it impossible to certify compliance. Similarly, it stated that, 
under the test procedures as written, a vehicle can be tested unlimited 
times until one failed test trial occurs, in which case the vehicle 
would be non-compliant.
Agency Analysis
    NHTSA is not granting reconsideration on this issue for two 
reasons. First, the purpose of FMVSS No. 127 testing is not to be an 
endurance or durability test, but a test of as-new hardware. This 
purpose is apparent in the structure of the rule compared with several 
other FMVSSs. When there are endurance and/or wear requirements in the 
FMVSSs, these requirements are apparent (i.e., they are titled 
``durability'' or ``endurance'' tests) or are specifically written to 
indicate minimum required durability limits.\58\ For example, FMVSS No. 
106 contains a water absorption and whip resistance requirement, which 
identifies both the length of time the hose sample will be submerged 
under water, and how long the hose sample will be flexed.\59\ There are 
numerous other examples in FMVSS No. 106 and other FMVSSs of this style 
of endurance testing that establishes a minimum durability performance. 
FMVSS No. 127 contains no such provisions. It was not written to, and 
is not intended to, set endurance or wear limits on the base equipment 
making up the AEB system. Instead, FMVSS No. 127 is intended to ensure 
a minimum level of performance of AEB systems. The only expected wear 
on the components is what is necessary for establishing a repeatable 
test, which is specified in the test procedures (i.e., brake 
burnishing). In the event that wear and tear result in an apparent non-
compliance during agency testing, the agency would not consider these 
tests valid. The Agency has demonstrated, through decades of testing, 
the competency to determine if wear is the source of an apparent non-
compliance, be it by conducting additional testing, disassembly and 
visual inspection, and other similar methods. Finally, any specific 
limits on preconditioning driving time or test runs would be

[[Page 93211]]

arbitrary. Therefore, given that that FMVSS No. 127 does not establish 
an endurance or durability test, NHTSA determined it is not necessary 
to specify such limits.
---------------------------------------------------------------------------

    \58\ See, e.g., FMVSS No. 108, S14.9.3.6, Turn signal flasher 
durability test; FMVSS No. 111, S5.5.7, Durability and S14.3, 
Durability test procedures; FMVSS No. 139, S6.3 Tire Endurance; and 
FMVSS No. 209, S4.2(d) and S5.1(d), which establish a test for the 
resistance of seat belt webbing to abrasion.
    \59\ S5.3.7, Water absorption and whip resistance (``A hydraulic 
brake hose assembly, after immersion in water for 70 hours (S6.5), 
shall not rupture when run continuously on a flexing machine for 35 
hours (S6.3).'').
---------------------------------------------------------------------------

    Second, manufacturers misunderstand the purpose of the pretest 
conditioning language. The initial conditions contained in S6, S7, S8, 
and S9, are written to prevent designing the AEB system to sense 
specific pre-conditions of the test. They are not intended to enable 
the agency to conduct durability testing. For instance, petitioners 
expressed concern that the standard states that the agency will drive 
the vehicle in any direction for any amount of time prior to the start 
of the test. However, additional conditions listed in S6 state that 
consumable fluids (including fuel), or battery charge for electric 
vehicles, will be between 5 and 100 percent. Additionally, the 
initialization conditions state that the vehicle will be driven at a 
speed of 10 km/h or higher for at least one minute prior to testing and 
subsequently the starting system is not cycled off prior to testing. 
Because the starting system is cycled off during fuelling, these 
conditions provide a practical and realistic limit on the amount of 
time the agency can drive the vehicle during preconditioning prior to 
any single test. Therefore, petitioners' concerns regarding ``unlimited 
pretest driving'' are misplaced.
    As such, reconsideration is unnecessary to resolve petitioners' 
concerns. Therefore, NHTSA declines to amend the final rule on this 
issue.

E. Malfunction Indicator Lamp

    The final rule requires that vehicles must detect AEB system 
malfunctions and notify the driver of any malfunction that causes the 
AEB system not to meet the minimum proposed performance requirements.
    The Alliance and Volkswagen stated that the requirement that the 
malfunction indicator lamp (MIL) illuminate under all malfunction 
conditions, including sensor degradation, and under all possible 
conditions of ``adjustments in performance'' lacks objectivity and 
practicability. The Alliance petitioned NHTSA to issue an SNPRM that 
would define each malfunction requiring MIL illumination and include an 
associated test procedure. It did not provide any additional data or 
analysis beyond what has already been considered in comments to the 
NPRM.
    The Alliance noted that while the requirement for activating a MIL 
in the event of a malfunction in an AEB system is consistent with other 
FMVSSs, the final rule neither explicitly defines malfunction nor 
provides the associated test procedures. Several petitioners requested 
an objective definition of ``malfunction.'' The Alliance pointed out 
that FMVSS No. 135 specifies conditions for MIL activation, and FMVSS 
No. 138 provides malfunction conditions and test procedure for the tire 
pressure monitoring system. In contrast, it stated, ``malfunction'' in 
FMVSS No. 127 is not defined and could include sensor degradation, 
which exceeds typical MIL illumination requirements in the FMVSSs. It 
stated that without a clear definition, manufacturers may determine a 
malfunction at their discretion and adjust AEB performance to any 
performance level, including complete deactivation, that does not meet 
the requirements of the final rule. The Alliance stated that if its 
interpretation is correct, the standard should clearly specify the 
allowance to adjust AEB systems, including complete deactivation, 
during a defined malfunction state.
    Additionally, the Alliance stated that NHTSA did not establish an 
objective test procedure for automatically detecting system changes 
that may affect AEB performance. The Alliance stated that the 
requirement to detect vehicle owner's modifications that could render 
the AEB system non-compliant is boundless and lacks specific, objective 
performance criteria and test procedures, unlike other FMVSSs. For 
example, FMVSS No. 138 provides specific test procedures where the MIL 
must illuminate when an incompatible tire is installed. In contrast, 
the final rule does not limit or specify the types of owner 
modifications that may trigger MIL illumination, making it unreasonable 
to expect manufacturers to anticipate and develop detection strategies 
for every possible modification scenario. It stated that, as a result, 
the MIL requirement is not objective.
    Toyota petitioned for reconsideration of MIL requirements and 
incorporated the Alliance's petition into its own. Additionally, Toyota 
provided a description of its understanding of the malfunction 
requirements. It read the requirements to allow discretion to the 
manufacturer to design a malfunction detection feature--including what 
elements to monitor and what is considered a malfunction. It also 
stated that if a malfunction is identified, the standard permits the 
manufacturer, at its discretion, to adjust the performance of the 
vehicle such that it will not meet the requirements specified in 
paragraphs S5.1, S5.2, or S5.3, including completely deactivating the 
AEB system, and illuminate the telltale. It said it understood the 
agency's intent to be that manufacturers must design vehicles with a 
malfunction detection feature, and that the vehicle must display a 
telltale when a malfunction is detected and allow the vehicle to adjust 
the performance of the AEB system or deactivate it in response to 
malfunctions.
    Toyota agreed with NHTSA that malfunctions should be detected based 
on the system design. Toyota argued that if the AEB system cannot be 
deactivated in cases of performance degradation, such as from sensor 
misalignment, it could result in false-positive activations potentially 
creating safety disbenefits. However, it nonetheless argued that the 
malfunction detection requirements are unclear and requested 
reconsideration. It noted that NHTSA had rejected suggested language 
from Bosch regarding malfunction detection on the basis that it was not 
workable for an FMVSS and lacked objectivity.
Agency Analysis
    NHTSA will not adjust the malfunction detection requirements. NHTSA 
considered comments on malfunction detection in the final rule. 
Petitioners broadly expressed confusion about the term ``malfunction'' 
and about what conditions the indicator lamp must illuminate. However, 
Toyota, in its petition, correctly summarized the requirements, 
indicating that it understood the requirement as written. Nonetheless, 
we respond to certain issues raised in the petitions to clarify our 
intent.
    Toyota is correct that, when a malfunction is detected, the system 
is permitted to reduce functionality and it must show the telltale. The 
intent behind the requirement is for systems to self-diagnose issues 
that cause them to perform at a level below that required by the FMVSS, 
adjust performance as the system determines is appropriate, and alert 
the operator. In contrast to how petitioners describe the requirement, 
the standard does not require AEB systems to detect all possible 
conditions (or owner modifications) that could reduce functionality. 
Rather it requires the system to be able to make detections regarding 
malfunctions and conditions that cause performance degradations, allows 
the system to adjust performance if it makes such a detection, and 
requires the system to alert the operator if such an adjustment is 
made.
    As is customary with NHTSA's standards, the laboratory compliance

[[Page 93212]]

test procedures will specify how NHTSA intends to run its compliance 
test regarding illumination of a malfunction telltale. However, NHTSA 
is not specifying these in the regulation. The conditions under which 
the malfunction lamp are required to illuminate are sufficiently 
defined in the FMVSS, which is enough information for manufacturers to 
certify to the requirement. Although NHTSA is also not specifying in 
the regulatory text how an internal malfunction is generated, test 
procedures for MIL requirements typically involve creating an obvious 
failure condition, such as disconnecting the power source to the 
system, and determining if the MIL illuminates.
    NHTSA will not specify instances of ``malfunction.'' NHTSA received 
and fully considered comment on this issue. The range of possible 
malfunctions is sufficiently broad that such an approach would be 
unlikely to meet the need for safety because it would omit many 
possible malfunctions from the MIL requirement. As Toyota stated, what 
constitutes a malfunction is specific to the design of each AEB system, 
and manufacturers are best positioned to determine when a circumstance 
exists that causes performance to be impeded.
    Furthermore, petitioners are incorrect when they state that the MIL 
requirement is not objective or practicable because the term 
``malfunction'' is not given a regulatory definition. The MIL 
requirement in FMVSS No. 127 is stated in objective terms. It ties the 
requirement to illuminate the MIL upon performance adjustment to the 
performance requirements for AEB systems. These performance 
requirements are stated in objective terms. The MIL requirement is 
therefore also stated in objective terms.
    Finally, the Alliance attempts to reference the MIL requirement in 
FMVSS No. 138 as a contrasting example of a MIL requirement that is 
objective. However, FMVSS No. 138, like FMVSS No. 127, does not provide 
an explicit definition of ``malfunction,'' instead applying the 
performance requirement ``to a malfunction that affects the generation 
or transmission of control or response signals.'' \60\ The approach 
undertaken in FMVSS No. 127 is analogous: it specifies the AEB system 
performance requirements, stated in objective terms, as the relevant 
comparison. Therefore, no reconsideration is necessary. NHTSA is 
denying the petitions for reconsideration on this issue and is not 
changing the MIL requirements from those stated in FMVSS No. 127.
---------------------------------------------------------------------------

    \60\ 49 CFR 571.138.
---------------------------------------------------------------------------

F. Deactivation

    The final rule includes an explicit prohibition against 
manufacturers installing a control designed for the sole purpose of 
deactivation of the AEB system, except in certain cases relating to law 
enforcement. The final rule does, however, allow for controls that have 
the ancillary effect of deactivating the AEB system, such as during 
low-range four-wheel drive configurations, when the driver selects 
``tow mode,'' or when another vehicle system is activated that will 
have a negative ancillary impact on AEB operation. It also allows for 
automatic deactivation in the malfunction circumstances described in 
the previous section.
1. Manual Deactivation
    The Alliance and Volkswagen petitioned NHTSA to allow manual 
deactivation of the AEB system. Petitioners pointed out scenarios in 
which they state that AEB operation can be inappropriate or potentially 
hazardous. These include racetrack usage, off-road driving that 
requires manoeuvring around obstacles, off-road driving without low 
range or gear options, road infrastructure causing false positives, 
support vehicles for cycling races, and similar situations or dynamic 
driving events involving interactions with other vehicles. The Alliance 
also raised several scenarios where vehicles are used on public roads 
but under non-normal conditions, such as during parades, car shows, or 
sport events where vehicles are operated in close proximity to 
pedestrians and other vehicles. Petitioners stated that the automatic 
deactivation provision is inadequate to address these scenarios. The 
Alliance noted that, since AEB systems might not automatically 
differentiate between tracks or parking lots and public roads, they 
could potentially intervene during dynamic driving manoeuvres, 
disrupting the driver and posing a risk to nearby vehicles. Moreover, 
the Alliance noted concerns about the ``automatic deactivation only'' 
approach for installed equipment, using snowplows as an example, 
stating that the final rule does not cover all potentially unsafe 
scenarios. For instance, installing equipment like a roof-mounted 
kayak, canoe, or ski rack with parts overhanging the front windshield 
could cause sensors to detect shapes that might not lead to a 
malfunction but could inadvertently trigger AEB operation. Thus, it 
requested that drivers have the ability to disable AEB systems to 
resolve these circumstances.
    The Alliance also requested expansion of the language in S5.4.3 of 
the final rule, which applies only to vehicles operating in a low-range 
four-wheel drive configuration, to include certain modern vehicle 
configurations, like those with all-wheel drive system without a 
transfer case or electrical vehicles using only electric motors or a 
combination of combustion-driven axles and electric motors, which may 
not have a low-range system but are still capable of off-road 
operations. Thus, the Alliance argued, NHTSA should broaden the 
applicability of S5.4.3 to include vehicles operating in any off-road 
mode or mode designated to the driver as appropriate for low-speed off-
road operations.
Agency Analysis
    NHTSA will not adjust the requirements regarding deactivation. 
NHTSA received and considered comments on automatic and manual 
deactivation of AEB systems. After consideration of those comments, 
NHTSA determined that allowing automatic deactivation pursuant to the 
circumstances in S5.4.2.2 would be practicable and most effectively 
meet the need for safety because it allows for controls that have the 
ancillary effect of deactivating the AEB while preventing installation 
of a control with the sole purpose of enabling driver disablement of 
AEB systems. NHTSA believes that the current regulatory text, which 
allows AEB deactivation ``when another vehicle system is activated that 
will have a negative ancillary impact on AEB operation,'' is 
sufficiently broad to encompass the vehicle types that the Alliance 
raises. Furthermore, the purpose of S5.4.3 is to exempt vehicles that 
have four-wheel drive modes, selected by mechanical controls that 
cannot be automatically reset electrically, from the requirement that 
any AEB deactivation be reset by the ignition cycle. For other vehicles 
(such as those with all-wheel drive), the agency expects that AEB will 
reactivate when the vehicle is in a drive mode that allows for AEB 
activation, and when the vehicle's ignition/power is cycled on/off.
    Petitioners' stated concerns about operation of vehicles with no 
manual AEB deactivation in unusual circumstances do not justify 
reconsideration. As we discussed in the final rule regarding front-
mounted equipment, a well-designed AEB system will be able to detect 
and automatically deactivate to accommodate roof-mounted equipment such 
as kayaks or

[[Page 93213]]

ski racks that may overhang the front windshield. We are also 
unpersuaded by requests that the final rule allow manual deactivation 
to account for various racing or track scenarios. The allowance in 
S5.4.2.2 provides relief for some of these vehicles. Additionally, our 
requirements apply to motor vehicles, which the Safety Act defines as a 
vehicle ``manufactured primarily for use on public streets, roads, and 
highways.'' \61\ Therefore, if a manufacturer chooses to produce a 
racing vehicle designed for use on public roads it must meet the 
minimum safety requirements. The fact that it may be used in a racing 
environment does not in and of itself justify a manual deactivation 
feature. Manufacturers may design racing vehicles not for use on public 
roads that do not meet the FMVSS.
---------------------------------------------------------------------------

    \61\ 49 U.S.C. 30102.
---------------------------------------------------------------------------

2. UNECE Regulation No. 152
    Volkswagen and the Alliance requested reconsideration of the 
agency's decision to disallow a manual deactivation feature based on 
data submitted by Volkswagen. Petitioners stated that data collected in 
Europe showed that, among a fleet of over 30,000 UNECE Regulation No. 
152 compliant vehicles which collectively took more than 12 million 
trips, only 0.2 percent of the vehicles deactivated their AEB systems 
more than 10 times. According to petitioners, this data indicates that 
less than 0.005 percent of all trips involved AEB deactivation and that 
while drivers did use the manual deactivation feature, they did so very 
rarely. Thus, they argued that allowing the manual deactivation 
feature, with appropriate multi-step procedures to prevent inadvertent 
deactivation, would not significantly diminish the overall benefits of 
AEB systems.
Agency Analysis
    NHTSA is unpersuaded that the data provided by Volkswagen 
demonstrates that NHTSA should adopt the approach taken by UNECE 
Regulation No. 152. Generally, the driving environment (road and lane 
design, etc.) and driver habits in the United States differ 
substantially from those in Europe, and there is also significant 
variation within European nations. These differences may result in 
differences in how drivers interact with AEB technology. The 
petitioners did not present evidence that data from the European market 
accurately represents driver behaviour in the U.S. market. In view of 
the safety concerns expressed in the final rule and by commenters, 
harmonization alone is an insufficient justification for allowing a 
control to deactivate the AEB system. As a result, we will not adopt 
the UNECE Regulation No. 152 approach.
    Therefore, no reconsideration is necessary. NHTSA is denying the 
petitions for reconsideration regarding amending the automatic 
deactivation provision or the restriction on installing a manual 
deactivation control.

G. Obstructed Pedestrian Crossing Test Correction

    The final rule contains a test scenario in which an obstructed 
pedestrian enters the path of the vehicle from the right.
    In its petition for reconsideration, the Alliance argued this 
performance test requirement demonstrates that the final rule is 
impracticable. The Alliance asked NHTSA to reduce the maximum test 
speed and align the headways more closely with the results of NHTSA's 
testing.
    The Alliance provided a case study of a narrow vehicle avoiding 
contact with the test mannequin using the boundary conditions specified 
in the rule and realistic vehicle stopping dynamics (a peak braking 
acceleration of 0.9 g and an initial braking rate of 3 g/s). The 
Alliance stated in its analysis that, when using nominal tolerances on 
the location of the vehicle test device relative to the subject vehicle 
positioning, the vehicle with a width of 1570 mm (61.8 in) had 
approximately 0.35 seconds to identify the crossing pedestrian and 
begin braking. However, in its analysis, when that same subject vehicle 
was at the maximum distance away from the intended travel path, and the 
vehicle test device was located as close to the side of the subject 
vehicle, only 0.15 seconds were available to react to the crossing 
mannequin. The Alliance stated that a response time of 0.15 seconds is 
beyond the capabilities of any AEB system and is not practicable.
Agency Analysis
    Agency calculations confirmed the issue raised by the Alliance 
regarding the perception time in obstructed pedestrian testing at the 
maximum allowable test tolerances. However, the agency does not agree 
that this finding is an indication of the standard's fundamental 
impracticability. Therefore, NHTSA is amending the requirement to align 
with the intent of the scenario to ensure that the specified tolerances 
do not result in an unintentionally stringent test.
    The final rule specified that subject vehicles would nominally be a 
meter away from the side of the vehicle test device when performing 
obstructed pedestrian testing. As the Alliance highlighted, the 
tolerance of the subject vehicle relative to the intended travel path 
(+/- 0.15 m), and the tolerance of the vehicle test device relative to 
the side of the subject vehicle (+/- 0.1 m) could add up such that the 
minimum distance could be 0.75 m instead of the intended 1 m. The 
reduction of the intended distance between the vehicle and the 
pedestrian mannequin by 25 percent has a significant impact on how much 
time the system has to determine whether to initiate braking. 
Additionally, as the Alliance highlighted, because we were primarily 
determining the vehicle test device location relative to the side of 
the subject vehicle, the narrower the vehicle, the less time that 
vehicle has to perceive the obstructed pedestrian and decide to begin 
braking. For narrower vehicles, this scenario renders the test more 
stringent than NHTSA intended.
    To address the issue, the agency is adjusting how the tolerances 
are defined in S8.3.3, so that at most, the vehicle test device is not 
less than 1.0 m away from the 0 percent overlap point (the right side 
of the vehicle). For vehicles up to 2.05 m (79.5 in) wide, which is a 
majority of passenger cars, the left side of the vehicle test device 
will be no less than 2.2 m away from the intended travel path. This 
standard places the left side of the vehicle test device at least 1.15 
m away from the right side of the subject vehicle, which accounts for 
the +/- 0.15 m lateral tolerance of the subject vehicle relative to the 
intended travel path prior to braking. To make sure testing is 
consistent, and to make sure that testing stringency does not increase 
for vehicles wider than 2.05 m (79.5 in), the left side of the vehicle 
test device will be no less than 1.15 m away from the subject vehicle.
    Therefore, NHTSA is amending the specifications for the obstructed 
pedestrian crossing test.

H. FCW Auditory Signal

1. FCW Auditory Signal Requirements
    The final rule requires the FCW auditory signal to have a high 
fundamental frequency of at least 800 Hz, a tempo in the range of 6-12 
pulses per second, and a duty cycle in the range of 0.25-0.95, and a 
minimum intensity of 15-30 dB above the masked threshold.
    The Alliance stated that the requirements related to the auditory 
signal lack specificity and were therefore not objective. The Alliance 
stated that the threshold sound level largely depends on the ambient 
noise at

[[Page 93214]]

a given moment in time and conditions such as vehicle speed and engine, 
tire/road, and wind noise. It concluded that for the requirement to be 
objective, NHTSA must clearly define several key characteristics, 
including the test conditions under which both the ambient noise and 
the masked threshold are measured as well as the methodology to measure 
and compute the sound level of the FCW warning and the noise separation 
amount (i.e., 5 dB). The Alliance also stated that there may need to be 
exceptions for high ambient noise conditions, such as convertibles with 
an open top.
    Volkswagen similarly commented that additional information relating 
to compliance testing is needed such as details of the means and 
conditions for measuring the reference noise level to which the 
regulation will compare the FCW auditory signal and inquired whether 
the vehicle's windows would be open and/or HVAC system would be active 
during the testing. The Alliance, as part of its comments regarding the 
audio suppression requirement (the remainder of which are discussed in 
the next subsection), also requested additional conditions regarding 
the ``masked threshold'' and how it will be assessed. Volkswagen also 
questioned the meaning of ``quietest level'' in the masked threshold 
definition and how to measure it. It further asked whether masked 
threshold would be determined based on a person with normal hearing or 
impaired hearing.
Agency Analysis
    In response to petitions, NHTSA is incorporating additional 
description of the conditions in which the FCW auditory requirements 
must be met, detailing the location of the sound measurement device, 
and replacing ``masked threshold'' with ``average noise level inside 
the vehicle.'' We are incorporating them to ensure clarity and to 
facilitate compliance.
    We are adding several specifications to the FCW auditory 
requirement. First, that the auditory signal requirements must be met 
at the highest SV test speed (which is 100 km/h). Second, we are 
specifying that the audio requirements are met with all vehicle 
openings closed. This language is intended to clarify for certifying 
entities that during the test, openings such as the windows, doors, 
hood, rear hatch, and trunk will be closed, as will convertible tops. 
Third, the provision now states that all subject vehicle sound-
producing systems or functions are set to off, other than those 
necessary for performing testing under the rule. This language is 
intended to describe systems such as the HVAC, windshield wipers, and 
turn signals, which produce noise that may impact measurement of sound 
inside the vehicle, but which are not necessary for testing. These 
additions provide significant clarity regarding the conditions under 
which the signal will be measured. The FMVSS already states that FCW 
must operate under the conditions in S6, which includes items that may 
impact the in-vehicle sound environment, such as the environmental 
conditions, road conditions, subject vehicle conditions, and equipment. 
Therefore, those conditions will not be further specified.
    NHTSA is also incorporating the intended sound measurement 
location, adjacent to a 50th percentile male driver's right ear tragion 
point. This point is identified in the anthropometric data from a 
NHTSA-sponsored study of the dimensions of 50th percentile male drivers 
seated with a 25-degree seatback angle (``Anthropometry of Motor 
Vehicle Occupants'').\62\ The tragion is an anthropometric point 
situated in the notch just above the tragus of the ear and is located 
614 mm vertically above the H point (hip location of a driver in the 
driver seating position), 185 mm aft of the H point, and 83 mm to the 
right of the H point.
---------------------------------------------------------------------------

    \62\ This report is the same as the one used as a basis for eye 
midpoint location set in FMVSS No. 111.
---------------------------------------------------------------------------

    We are also simplifying the baseline sound level against which the 
FCW auditory signal intensity is compared by replacing the term 
``masked threshold'' with ``average noise level inside the vehicle.'' 
We are also incorporating a description of how that level will be 
determined: by measuring the noise level inside the vehicle over a 5-
second period under the conditions described above. This change 
resolves items raised by petitioners regarding defining additional 
aspects of the ``masked threshold'' as well as Volkswagen's petition 
regarding the hearing ability of the reference driver by simplifying 
the measurement to focus solely on the noise level inside the vehicle.
    Therefore, NHTSA is incorporating these three changes to clarify 
the requirements applicable to the FCW auditory warning.
2. In-Vehicle Audio Suppression Requirement
    The final rule required that in-vehicle audio that is not related 
to a safety purpose or safety system (i.e., entertainment and other 
audio content not related to or essential for safe performance of the 
driving task) must be muted, or reduced in volume to within 5 dB of the 
masked threshold during presentation of the FCW auditory signal.
    The Alliance requested reconsideration of the requirement. The 
Alliance and Volkswagen stated that the requirement lacked objectivity 
and a corresponding test procedure. The Alliance requested that NHTSA 
eliminate the requirement or issue an SNPRM proposing to define the 
audio sources that must be suppressed and ``safety purpose or safety 
system'' sounds that are not required to be suppressed. It also asked 
NHTSA to propose performance requirements defining the threshold for 
when the audio suppression must begin, with an associated test 
procedure. Finally, the Alliance argued that NHTSA did not adequately 
consider consumer satisfaction concerns with the suppression 
requirement and that consumers may be unaccustomed to it, believing 
their audio is not working or seeking to disable the audio suppression 
feature.
a. Types of Sounds that Must be Suppressed
    The Alliance stated that the phrase ``not related to a safety 
purpose or a safety system'' contains undefined terms that are not 
explained except with a parenthetical reference to entertainment. The 
Alliance, in its petition, noted that audio suppression systems cannot 
distinguish between certain content that may or may not have a safety 
purpose: for example, a radio broadcast of a talk show host versus a 
radio broadcast of an emergency weather alert. It noted that the 
language may result in suppression of broadcasts of FEMA's Integrated 
Public Alert and Warning System, which the Alliance noted was 
established by Executive Order 13407 to ensure that the public has 
access to critical alerts about weather and other emergencies. 
Petitioners also requested that NHTSA provide definitions indicating 
which audio sources must be suppressed and which do not. The Alliance 
mentioned examples for which it was not sure whether the suppression 
requirement would apply, such as the HVAC, defroster, seat belt 
reminder alarms, intelligent speeding assist indicators, and road 
departure alerts.
Agency Analysis
    In response to this petition, NHTSA is amending the language to 
clarify that the requirement is to suppress audio not related to a 
crash avoidance warning. The intent of the requirement was to ensure 
that auditory signals unrelated to the vehicle's crash avoidance 
response in an imminent crash avoidance

[[Page 93215]]

scenario would not interfere with the driver's perception of the FCW 
and thereby hinder their opportunity to intervene and avoid a crash. 
Given that petitioners' concerns appear to be regarding vagueness, 
NHTSA is clarifying the requirement to reference a more specific set of 
audio signals that should not be suppressed: in-vehicle audio that is 
``not related to a crash avoidance system warning.'' \63\ NHTSA is also 
removing the explanatory parenthetical associated with ``safety purpose 
or safety system,'' as it is no longer applicable. This change also 
resolves concerns with systems being able to distinguish between 
regular and emergency broadcasts, because emergency broadcasts are not 
related to a crash avoidance system warning and would therefore need to 
be suppressed.
---------------------------------------------------------------------------

    \63\ The examples used by the petitioners, including ``seat belt 
reminder alarms,'' ``intelligent speeding assist indicators,'' and 
``road departure alerts,'' should be evaluated by the manufacturer 
based on their propensity to assist a driver in avoiding a crash. 
While NHTSA could have chosen to state that, for example, audio from 
systems other than ``Advanced Driving Assistance Systems (ADAS)'' 
should be muted, the term ``ADAS'' has only been in use for 
approximately a decade and may describe a broader array of alerts 
than is appropriate.
---------------------------------------------------------------------------

    Regarding the Alliance's question whether a vehicle's HVAC system 
and window defrosting system should be considered in-vehicle audio, 
they should not. In-vehicle audio is to be understood to refer to 
auditory signals and content produced or transmitted by the vehicle for 
the purpose of communicating information, entertainment, or other 
purpose not related to or essential for safe performance of the driving 
task. Although the regulation does not define ``audio,'' NHTSA's 
understanding of the term is consistent with its plain meaning. For 
example, Webster's dictionary defines the noun, ``audio,'' to refer to 
``an audio signal.'' \64\ Cambridge Dictionary defines the noun 
``audio'' to mean ``a sound recording, or recorded sound.'' \65\ These 
definitions suggest ``audio'' to refer to purposeful sounds emitted to 
communicate or provide some form of information (including 
entertainment). Noise stemming from the operation of HVAC systems or 
windshield defrosters would not be considered ``in-vehicle audio.'' On 
the other hand, auditory navigation instructions are considered audio 
and are subject to the suppression prevision. Therefore, the regulation 
is clear as written.
---------------------------------------------------------------------------

    \64\ https://www.merriam-webster.com/dictionary/audio (accessed 
7/29/2024).
    \65\ https://dictionary.cambridge.org/dictionary/english/audio 
(accessed 7/29/2024).
---------------------------------------------------------------------------

    The arguments regarding consumer acceptance are not persuasive. An 
FCW alert is only required in a crash-imminent scenario, and the muting 
of in-vehicle audio would be accompanied by the FCW audio signal. In 
such a crash-imminent scenario, it is not evident that the muting of 
in-vehicle audio would be of any concern to a driver.
    Additionally, in responding to this petition, NHTSA examined 15 
model year 2016-2024 light vehicle models from 12 manufacturers to 
determine whether in-vehicle audio muting during FCW presentation was 
employed. Of 15 models examined, 11 models from 10 manufacturers were 
found to mute in-vehicle audio during FCW presentation. A twelfth 
vehicle (2022 Hyundai Tucson) reduced the volume of in-vehicle audio 
during FCW presentation. Three models did not appear to mute or reduce 
the volume of in-vehicle audio during FCW presentation (2022 Honda 
Odyssey, 2023 Nissan Pathfinder, and 2022 Subaru Outback). Aside from 
in-vehicle audio suppression during FCW, in-vehicle audio suppression 
under other circumstances is already present vehicles today as well. 
For example, some current vehicles mute in-vehicle audio while the 
vehicle's transmission is in reverse gear. Audio sources in the vehicle 
can also be muted by apps on a phone connected to the vehicle, such as 
the Ring app (camera motion notifications will mute vehicle audio 
sources) and the Waze navigation app, which mutes vehicle audio sources 
while audio route instructions and other app-based verbal information 
is provided. Given the ubiquity of suppression of in-vehicle audio 
during FCW presentation, as well as other vehicle features and phone 
apps that suppress the vehicle's entertainment system and other in-
vehicle audio, the petitioner's contention that customers will find the 
required audio suppression during FCW presentation to be unfamiliar and 
cause dissatisfaction is not compelling.
b. FCW Presentation and Suppression Timing
    The Alliance stated that the suppression requirement is not 
objective because it lacks a definition of ``presentation,'' and 
information regarding when the FCW must present or when suppression of 
in-vehicle audio must occur (such as whether it must occur immediately 
upon FCW presentation or within a specified period of time). It noted 
that NCAP, IIHS, and European procedures all contain a TTC value for 
when the FCW must present. Volkswagen and the Alliance also petitioned 
regarding the lack of an objective test methodology for the suppression 
requirement.
Agency Analysis
    Petitioners' arguments do not justify reconsideration on this 
issue. NHTSA is not incorporating a specified timing at which the FCW 
signal's onset must occur, a definition of ``presentation,'' or a 
regulatory test procedure for evaluating the suppression requirement. 
FCW is required without an associated timing requirement because there 
is no regulatory safety need to require FCW at for any particular 
amount of time prior to automatic braking. Therefore, the FMVSS gives 
manufacturers flexibility in determining the timing of the FCW 
presentation for their vehicles.
    NHTSA will also not provide a definition of ``presentation'' 
because the plain meaning of the term and its use in context is not 
vague or unclear.\66\ The term is used only once in the regulatory text 
to describe the suppression requirement. Additionally, ``FCW onset'' is 
defined as the first moment in time when a forward collision warning is 
provided. In understanding the meaning of ``presentation,'' 
manufacturers may consider viewing ``FCW onset'' as the moment at which 
``presentation'' begins, and that ``presentation'' encompasses the 
entire time that the audible signal is active. Additionally, given the 
short, approximately 1-2 second duration of most FCW auditory signals, 
any delay in suppressing other audio content could hinder the driver's 
ability to perceive the warning. As such, onset of the muting of in-
vehicle audio should be simultaneous with the onset of the FCW auditory 
signal. There is no reason to believe, and petitioners did not suggest, 
that AEB systems are incapable of sending concurrent commands to 
initiate both FCW presentation and muting of in-vehicle audio or that 
response times for sending commands to initiate the FCW and the 
suppression would be different. Therefore, NHTSA does not expect 
substantial delay in suppression.
---------------------------------------------------------------------------

    \66\ For example, Cambridge Dictionary defines ``presentation'' 
as a noun meaning ``the act of giving or showing something, or the 
way in which something is given or shown.'' https://dictionary.cambridge.org/us/dictionary/english/presentation 
(accessed 7/31/2024).
---------------------------------------------------------------------------

    Regarding a test procedure, the changes in this rule resolve many 
of the questions petitioners had regarding vehicle state and sound 
measurement such that manufacturers have clear guidance on the 
suppression requirement. Therefore, no additional test procedure will 
be added. However,

[[Page 93216]]

for clarity below we describe straightforward and readily apparent 
steps we expect to take in evaluating the requirement.
    NHTSA anticipates recording and evaluating audio data during the 
performance of the test scenario including the activation of FCW, and 
manufacturers may reasonably certify to the suppression requirement by 
using any of the required test scenarios while audio content subject to 
the muting requirement is playing (e.g., music). The first opportunity 
to measure the muted or reduced audio level would be during the period 
after the first FCW auditory signal pulse and before the start of the 
second pulse. Sound level would be recorded beginning some time before 
the onset of FCW and through the end of FCW presentation. Recorded 
audio data would be analyzed to extract sound level (in dB) values 
during the FCW pulse and the period between the first and second FCW 
auditory signal pulse. The sound level between pulses would be analyzed 
to demonstrate that the sound level had been reduced to the required 
level of within 5 dB of the average noise level inside the vehicle.
    For these reasons, no reconsideration is needed on this issue.

I. FCW Visual Signal

    The final rule states that the FCW visual signal must be located 
within an ellipse that extends 18 degrees vertically and 10 degrees 
horizontally of the driver forward line of sight based on the forward-
looking eye midpoint (Mf) as described in S14.1.5. of FMVSS No. 111. It 
also requires that the signal include the crash pictorial symbol in SAE 
J2400 and that the visual signal be red and steady burning.
    Both the Alliance and Volkswagen stated that the requirements are 
insufficient to be objective or for evaluating compliance and requested 
several revisions to the rule. The Alliance requested that NHTSA issue 
an SNPRM to propose performance requirements and test procedures.
    In response to the petitions, NHTSA has determined that 
reconsideration is warranted on some of the items and is making changes 
to the regulatory text to ensure clarity in the requirements. However, 
comment was sought on these issues in the NPRM, and NHTSA has 
determined that no additional opportunity for comment is necessary, as 
explained in section IV. Rulemaking Analyses and Notices.\67\ 
Therefore, NHTSA will not issue an SNPRM, and is finalizing the changes 
herein.
---------------------------------------------------------------------------

    \67\ Pursuant to 49 CFR 553.37, and in accordance with 5 U.S.C. 
553, the Administrator has the discretion to make a final decision 
or seek further comment when reconsidering a rule.
---------------------------------------------------------------------------

1. FCW Visual Signal Size
    In its petition, the Alliance stated that the FCW visual signal 
requirements do not define the size of the FCW symbol.
    NHTSA is not incorporating a size requirement for the FCW visual 
signal because there is no need for such a requirement. Not specifying 
a minimum or maximum FCW visual signal size provides manufacturers some 
flexibility in how the symbol is implemented for their system.
2. Dimensions of the FCW Visual Signal Location Elliptical Area
    Volkswagen requested clarification of the regulatory language 
regarding the required location of the FCW visual signal. Volkswagen 
noted that S5.1.1(b)(1) of the regulation states that ``[t]he visual 
signal must be located within an ellipse that extends 18 degrees 
vertically . . . of the driver forward line of sight,'' but that it is 
not clear whether this language means  18 degrees or  9 degrees from the driver's line of sight.
    NHTSA grants reconsideration on this issue and is amending the 
regulation to provide clarity. The regulatory language was intended to 
specify an elliptical cone extending 18 degrees vertically 
and 10 degrees horizontally from the driver's line of 
sight. Therefore, a plus-minus sign will be added.
3. Clarify Whether the FCW Visual Signal Needs To Be Fully Within the 
Ellipse
    Volkswagen stated that the requirements were unclear as to whether 
the entire FCW visual icon or only a portion of it must be located 
within the bounds of the elliptical cone.
    Reconsideration is justified on this issue. NHTSA intended the 
regulation to require that the required FCW symbol must be presented 
fully within the defined elliptical area and is updating the regulatory 
text to reflect this intent. NHTSA is incorporating the word ``symbol'' 
after ``visual signal'' in the S5.1.1(b)(1) to clarify that the symbol 
is what must be located within the specified area. If a manufacturer 
chooses to provide any additional visual warning components (e.g., 
illuminating the perimeter of the instrument panel, or surrounding the 
symbol with an illuminated, color-shaded shape), the additional 
components are not required to be located within the specified 
elliptical area.
4. Reference to FMVSS No. 111
    The Alliance and Volkswagen stated that S5.1.1(b) of the final rule 
requires the visual signal to be located in an ellipse formed around 
the forward-looking eye midpoint of the driver ``as described in 
S14.1.5 of FMVSS No. 111'' but does not specify the driver seat 
position and seat back angle or the steering wheel adjustment like 
FMVSS No. 111 does.
    Reconsideration is justified on this issue. Although explicitly 
stating these details is not essential because to accurately locate the 
driver eye midpoint ``test reference point'' as defined in FMVSS No. 
111 S14.1.5 it is necessary to follow the ``Driver Seat Positioning'' 
specifications in S14.1.2.5, NHTSA is changing the regulatory text for 
clarity to refer to S14 of FMVSS No. 111 instead of only S14.1.5. This 
change incorporates the relevant information from FMVSS No. 111.

J. Cost Estimates

    The Alliance argued that the agency did not adequately consider the 
costs of the requirements, including consideration of the disbenefits 
that might be induced by the new standard. It requested that NHTSA 
revise its cost assessment to consider more realistic assessments of 
the hardware additions and other changes that will be required by the 
final rule, as well as identify and quantify the disbenefits in terms 
of increased rear-end collisions and other crashes that will be induced 
by the final rule, at least for several more years. In its petition, 
the Alliance argued that the conclusions in the FRIA are not based on 
the rulemaking record or on the facts in the market and led NHTSA to 
substantially underestimate the costs of compliance with the new 
standard. Based on a survey of its members, the Alliance stated that 
the additional costs to make current systems compliant range from $200 
per vehicle on the low end to $4,200 per vehicle on the high end. The 
Alliance also claimed that NHTSA mischaracterized a meeting NHTSA had 
with Robert Bosch LLC (Bosch) regarding the percentage of vehicles in 
the fleet that may need hardware improvements.
    Volkswagen stated the cost analysis as reported in the FRIA does 
not represent the true cost of the final rule. For example, Volkswagen 
argued, the requirements of the final rule cannot be reasonably met 
with existing vacuum brake systems, and the PAEB requirements under 
conditions of darkness may necessitate infrared cameras. It stated that 
NHTSA did not

[[Page 93217]]

account for the costs for additional hardware in its analysis.
Agency Analysis
    The Alliance and Volkswagen's claims that the final rule did not 
adequately consider costs in improvements in AEB technology are 
mistaken. The Alliance's cost estimates are not correct estimates of 
the cost of compliance with the final rule because they include the 
cost of including head-up display (HUD) and lidar, neither of which are 
required to meet the requirements and account for a large portion of 
that higher estimate.
    Additionally, the final rule fully considered the cost concerns 
raised by petitioners. NHTSA sought and received comment regarding 
hardware costs. Comments did not indicate the incremental cost 
associated with additional hardware commenters believed was necessary 
to achieve the requirements or the percentage of new light vehicles 
that they believe would require additional hardware. Nevertheless, the 
cost analysis in the FRIA accounted for a small number of new light 
vehicles that may need additional hardware for their existing AEB 
systems, such as an additional camera or radar, by including the 
incremental cost of adding radar to five percent of new light 
vehicles.\68\ The Alliance disputed the 5 percent figure, noting that 
the information NHTSA received from Bosch suggests larger improvements 
are needed, and NHTSA received a letter from Bosch clarifying the 
figure.\69\ NHTSA appreciates Bosch's clarification. However, even if 
NHTSA accepts for the sake of argument that the incremental cost 
estimate undercounts that percentage of new light vehicles that need 
additional improvements in computing power or sensing technologies, 
NHTSA's analysis fully considered these costs because the FRIA also 
included a sensitivity analysis.\70\ The sensitivity analysis found 
that even in the case that 50 percent of new light vehicles would need 
to add radar to their current hardware and all new light vehicles 
needed a software upgrade, the final rule would remain highly net 
beneficial. The FRIA also includes a breakeven analysis that estimates 
the per-vehicle cost at which net benefits would be zero. Therefore, 
NHTSA's cost and benefits estimates for AEB system hardware and 
software were sufficient to support the final rule.
---------------------------------------------------------------------------

    \68\ One possible result of this assumption is that the cost 
analysis may in fact overestimate those incremental hardware costs 
because some vehicle manufacturers may add an additional camera at a 
lower cost than radar.
    \69\ Docket No. NHTSA-2023-0021-1077. The letter states that the 
5 percent figure ``is a significant misunderstanding and/or 
mischaracterization of the information provided by Bosch'' and that 
Bosch was describing only a rough estimate of the share of Bosch-
supplied AEB systems in the U.S. market that are mono-camera. Bosch 
also emphasized, both in the presentation given to NHTSA and in its 
comments on the NPRM, that certain models may require significant 
hardware updates such as improved sensors as well as computing power 
and/or improved brake systems.
    \70\ The sensitivity analysis in the FRIA for hardware 
considered the case in which 10, 20, or 50 percent of new light 
vehicles would need either an additional camera or radar to meet the 
requirements.
---------------------------------------------------------------------------

    NHTSA's analysis also considered comments and the available data 
regarding whether the final rule would necessitate improvements in 
vehicles' foundational braking system and found that it would not. The 
agency found that vehicles subject to the final rule would already be 
equipped with brakes that give them the braking capabilities to meet 
the performance requirements specified in the final rule.\71\ The FRIA 
discussed a summary of the braking test results from FMVSS No. 135 
testing.\72\ In all cases, vehicles covered by the final rule exceed 
the minimum requirements of the braking standards. The results further 
indicate that baseline vehicles already have the braking capabilities 
necessary to meet the minimum requirements for AEB. Additionally, NHTSA 
believes that the most cost-effective way (lowest cost option) for 
manufacturers to meet the requirements of FMVSS No. 127 is through 
tunning and calibration of the AEB systems rather than through 
increased braking capacity or additional brake hardware such as 
electro-hydraulic brake actuators. As NHTSA's analysis focuses on the 
lowest cost option that is estimated to be capable of meeting the final 
rule and the lowest cost option does not necessitate increased braking 
capacity, the costs incurred by increasing the foundational braking 
system were not considered. That being said, the agency provides 
flexibility in how manufacturers construct their AEB systems to meet 
the requirements and they may well choose to include brakes with 
increased capabilities. At any rate, the breakeven and sensitivity 
analyses demonstrate that even with significant per-vehicle hardware 
costs beyond those estimated in the FRIA, the final rule would remain 
cost-beneficial.
---------------------------------------------------------------------------

    \71\ FRIA at 40.
    \72\ FRIA, Table 267. The Alliance's stated concerns with the 
relevance of this test data are discussed in Section II.A.1.b 
``FMVSS No. 135 Test Data'' of this notice.
---------------------------------------------------------------------------

    Lastly, petitioners simultaneously claim that the final rule is 
impracticable but also that the requirements can only be met if certain 
hardware improvements are made. Given that the final rule would be 
economically practicable even with sizable increases in compliance 
costs, these statements are contradictory. Indeed, petitioners' claims 
regarding cost support the notion that the final rule is practicable by 
acknowledging the availability of technologies that can enable vehicles 
to meet the requirements.
    Therefore, no reconsideration is necessary. NHTSA is denying the 
petitions for reconsideration regarding NHTSA's cost estimates.

K. Brake Pedal Robot

    The final rule specified how the brake pedal force is applied 
during testing conducted with manual brake application. It left to the 
manufacturer the discretion to select the braking method that NHTSA 
will use when NHTSA tests the manufacturer's vehicles.
    Volkswagen requested reconsideration of the decision not to provide 
specifications for the brake pedal robot used in the manual braking 
tests. It stated that differences in test equipment between the 
agency's test contractors and the vehicle manufacturer could lead to 
inconsistencies in performance.
    NHTSA received comments on this issue (including from Volkswagen) 
and responded to them in the final rule. NHTSA clarified that the rule 
does not require use of a specified braking robot. The final rule 
specifies the brake pedal force application during testing, leaving it 
to the manufacturer's discretion to select the braking method for 
NHTSA's testing of its vehicles. The specification is sufficient to 
ensure test repeatability, especially given manufacturers' lengthy 
experience with braking robots in AEB testing. Since the petitioner did 
not present any new information that would warrant reconsidering the 
agency's prior conclusion, no reconsideration is necessary, and we are 
denying the petition for reconsideration regarding the brake pedal 
robot specifications.

L. Manual Transmission

    Glickenhaus petitioned NHTSA to reconsider and amend the standard 
to only require FCW (i.e., not AEB) for vehicles with manual 
transmission. Glickenhaus stated that substantial slowing or stopping 
from highway speeds in a vehicle with a manual transmission will stall 
the vehicle without manually shifting or engaging the clutch. It stated 
that sudden unnecessary braking caused by the final rule will cause a 
vehicle with a manual

[[Page 93218]]

transmission to stall, thereby reducing the functionality of the 
brakes. A stalled vehicle, Glickenhaus stated, can create an 
unreasonable risk if the vehicle is on the highway and cannot move out 
of the way. Further, Glickenhaus stated that NHTSA's existing standards 
have a precedent of differentiating requirements and testing procedures 
for manual transmissions from those for automatic transmissions where 
the technology requires. Glickenhaus provided examples of those 
standards and what it stated are the relevant sections. Additionally, 
Glickenhaus stated that one FMVSS testing facility it works with 
confirmed that whenever it runs AEB tests on any vehicle with an 
automatic transmission,\73\ the vehicle always stalls. Glickenhaus also 
stated that its manual gearbox supplier confirmed that will always be 
the case, and that this stalling could damage the drivetrain. 
Glickenhaus further stated that NHTSA recognizes that vehicle stalling, 
especially when unexpected at highway speeds, is a ``substantial'' 
hazard. Glickenhaus also stated that drivers using manual transmissions 
are more likely to be paying closer attention to the road than drivers 
of vehicles with cruise control, or any level of ``self driving'' 
vehicle functionality. Glickenhaus's petition stated that requiring 
only FCW for manual transmissions could increase safety by warning 
drivers while allowing them to place the vehicle into neutral or press 
the clutch to avoid stalling while braking.
---------------------------------------------------------------------------

    \73\ In its petition, Petitioner may have intended to state 
``manual'' instead of ``automatic'' here. Regardless, our response 
to the petitioned-for request is the same.
---------------------------------------------------------------------------

Agency Analysis
    NHTSA is unpersuaded that the technical limitations of AEB with 
manual transmission vehicles justifies excluding them from the AEB 
requirement. Our review of the fleet shows that AEB technology already 
exists for manual transmissions. Therefore, no reconsideration is 
needed.
    There are many light vehicles sold in the US which still offer 
manual transmission as an option or standard.\74\ Several vehicles 
equipped with manual transmissions, such as the 2024 Honda Civic Type 
R,\75\ 2024 Ford Bronco \76\ and 2024 Nissan Z,\77\ also come with AEB 
and PAEB as a standard feature. Due to the wide availability of 
technology from various suppliers with AEB and manual transmissions, 
NHTSA is not persuaded that only manual application of the clutch can 
prevent a stall.
---------------------------------------------------------------------------

    \74\ https://www.caranddriver.com/features/g20734564/manual-transmission-cars/ (accessed August 26, 2024); https://www.caranddriver.com/features/g15379070/manual-transmission-suv/ 
(accessed August 26, 2024).
    \75\ https://automobiles.honda.com/civic-type-r# (accessed 
August 26, 2024).
    \76\ https://www.ford.com/suvs/bronco/compare-models/?gnav=footer-shop (accessed August 26, 2024).
    \77\ https://www.nissanusa.com/vehicles/sports-cars/nissan-z/specs-trims.html, accessed August 26, 2024.
---------------------------------------------------------------------------

    NHTSA is also unpersuaded that drivers of manual transmission 
vehicles are more engaged such that excluding them from the AEB 
requirement would be justified. As noted in the final rule, the timing 
of AEB and PAEB events do not always allow sufficient time for the 
driver to react and apply the brakes when a FCW is presented, 
regardless of the level of driver engagement.
    Therefore, no reconsideration is necessary. NHTSA is denying the 
petition for reconsideration regarding requiring only FCW for vehicles 
with a manual transmission.

M. Small-Volume Manufacturers

    The final rule did not alter requirements for small-volume 
manufacturers but allowed an additional year for compliance for small-
volume manufacturers.
    Glickenhaus, which produces around 30 vehicles annually subject to 
the final rule, petitioned for reconsideration of the requirements for 
small-volume manufacturers, stating that the standard would cause 
substantial financial hardship. Glickenhaus stated it had contacted 
Tier 1 suppliers about AEB systems and was informed that the hardware 
for these systems is typically developed by larger manufacturers, and 
there is not a baseline set of hardware and software available for 
Glickenhaus to develop an AEB system for its very low volume vehicles. 
It noted that developing AEB hardware takes years, and the software 
calibration requires millions of miles of driving. Glickenhaus claims 
it cannot produce enough cars and drive them long enough to gather the 
necessary data to create compliant hardware and software for its very 
low volume vehicles. Therefore, according to Glickenhaus, unless Tier 1 
suppliers develop starting packages for small-volume manufacturers, it 
would be impossible to develop a rule compliant AEB system within the 
lead time provided.
    Glickenhaus further emphasized the challenges of software 
development, vehicle testing, and calibration miles, which it considers 
nearly impossible to achieve within the given timeframe, even with an 
additional year. It argued out that some manufacturers have spent over 
20 years developing and testing AEB systems, and that the costs of 
developing software and hardware for a driving automation system, 
including AEB functions, can exceed $ 10 billion annually--figures that 
the petitioner cannot manage.
Agency Analysis
    The agency initially proposed that the requirements would not apply 
to small-volume manufacturers until one year after the compliance date 
set for other manufacturers. NHTSA received more than 1,000 comments on 
the NPRM, including input from sensor developers that indicated that 
the technologies required to meet the standard are already 
available.\78\ In the final rule, the agency provided additional lead 
time for all manufacturers and continued to provide small-volume 
manufacturers an additional year beyond other manufacturers. Given the 
comments we received and the availability of these systems, we expect 
that small-volume manufacturers will be able to source rule-compliant 
AEB systems for their vehicles from existing technologies without 
incurring undue expenses in research and development.\79\
---------------------------------------------------------------------------

    \78\ 89 FR 39686, 39727.
    \79\ Id. at 39726-27, 39729, 39737.
---------------------------------------------------------------------------

    However, we acknowledge that there could be specific situations in 
which it may be particularly challenging for small-volume manufacturers 
to source systems. Without additional technical information regarding 
why Tier 1 suppliers could not provide AEB systems to the petitioner, 
we cannot provide further analysis regarding their circumstances. 
However, if the petitioner believes that the standard will cause 
substantial financial hardship and it has attempted to comply with the 
standard in good faith, it may be able to seek a temporary exemption 
pursuant to 49 U.S.C. 30113 and 49 CFR part 555, subject to a 
determination that an exemption is consistent with the public interest.
    Therefore, no reconsideration is necessary. NHTSA is denying 
Glickenhaus's petition for reconsideration of the requirements for 
small-volume manufacturers.

III. Petition for Rulemaking Received by NHTSA and Analysis

A. Include V2X

    In addition to the petitions for reconsideration discussed above, 
NHTSA also received a petition from Autotalks on June 26, 2024. 
Pursuant to 49 CFR 553.35, petitions for reconsideration must be 
received ``not later than 45 days after publication of

[[Page 93219]]

the rule in the Federal Register.'' Additionally, the regulation states 
that ``[p]etitions filed after that time will be considered as 
petitions filed under Part 552 of this chapter.'' \80\ Part 552 governs 
petitions for rulemaking. Although Autotalks's petition requested 
revision of the final rule, given that Autotalks's petition was 
received by NHTSA more than 45 days after publication of the final 
rule, NHTSA will treat that petition as a petition for rulemaking.
---------------------------------------------------------------------------

    \80\ 49 CFR 553.35(a).
---------------------------------------------------------------------------

    Pursuant to Part 552, when deciding on a petition for rulemaking 
the agency conducts a technical review of the petition, which may 
consist of an analysis of the material submitted, together with 
information already in possession of the agency. In deciding whether to 
grant or deny a petition, the agency considers this technical review as 
well as appropriate factors, which include, among others, allocation of 
agency resources and agency priorities.
    In its petition, Autotalks requests incorporating a V2X transmitter 
to the lead vehicle and activating it during the lead deceleration test 
with a 12-meter gap (Table 1 to S7.1). Autotalks argues that this 
requirement will allow the tested vehicle to use V2X to complement its 
sensors. Autotalks provides technical information regarding the 
capabilities and availability of V2X technology.
1. NHTSA's Consideration of the Petition and Decision
    NHTSA has conducted an analysis of Autotalks's petition and, after 
careful consideration, has decided to deny the petition and will not 
initiate rulemaking proposing to require the installation and use of a 
V2X transmitter in lead vehicle deceleration AEB testing with 12-meter 
headway, for the reason stated below.
    In November 2023, NHTSA withdrew a proposed rule which had proposed 
to establish a new FMVSS mandating V2V (vehicle-to-vehicle) 
communication technology in all new light vehicles.\81\ After reviewing 
comments on the NPRM, NHTSA determined that, although V2V and V2X 
technologies may improve safety and offer innovative services to 
consumers, significant analysis would be needed before determining 
whether a new V2V standard is appropriate, and, if so, what that 
standard would encompass. NHTSA's position has not changed since then 
and Autotalks has not provided information to change that position. 
Therefore, NHTSA will not initiate a rulemaking to require V2X 
technologies in AEB systems as a result of this petition. As we stated 
in the November 2023 withdrawal notice, NHTSA will continue to monitor 
the development of this technology for possible future vehicle safety 
applications.
---------------------------------------------------------------------------

    \81\ 88 FR 80685.
---------------------------------------------------------------------------

2. Conclusion
    In accordance with 49 U.S.C. 30162 and 49 CFR part 552, the 
petition for rulemaking from Autotalks is denied.

IV. Rulemaking Analyses and Notices

    This rule is a non-significant rule for purposes of Executive Order 
(E.O.) 12886, as supplemented by E.O. 13563 and amended by E.O. 14094, 
and will not impose any significant costs or have impacts beyond those 
analyzed in the final rule published on May 9, 2024.\82\ DOT has 
determined that the regulatory analyses conducted for the May 9, 2024 
final rule remain applicable to this action. DOT makes these statements 
on the basis that this final rule makes technical or clarifying changes 
to FMVSS No. 127 as established in the May 9, 2024 final rule. In 
addition, this final rule is not expected to impact the estimated costs 
and benefits detailed in the final regulatory impact analysis included 
in the docket listed in beginning of the final rule published on May 9, 
2024.
---------------------------------------------------------------------------

    \82\ 89 FR 39686.
---------------------------------------------------------------------------

    NHTSA finds it has good cause to make these changes without notice 
and comment pursuant to the Administrative Procedure Act (APA, 5 U.S.C. 
551, et seq.). Section 553(b)(B) of the APA provides that, when an 
agency for good cause finds that notice and public procedure are 
impracticable, unnecessary, or contrary to the public interest, the 
agency may issue a rule without providing notice and an opportunity for 
public comment. The May 2024 final rule is the product of an extensive 
administrative record with opportunity for public comment on the issues 
discussed in this final rule. The changes in this final rule are made 
in response to petitions for reconsideration submitted to NHTSA in 
response to and docketed in the record of the May 2024 final rule in 
accordance with 49 CFR 553.35 and 49 CFR 553.37.\83\ In response to 
those petitions, NHTSA makes only clarifying changes to the May 2024 
final rule to align the regulatory text with the explanatory material 
in the preamble of that final rule.
---------------------------------------------------------------------------

    \83\ These regulations grant to the Administrator the authority, 
consistent with 5 U.S.C. 553b(B), to issue a final decision in 
response to petitions for reconsideration without further 
proceedings or with opportunity for further comment as the 
Administrator deems appropriate.
---------------------------------------------------------------------------

    Specifically, NHTSA removes the term ``imminent'' from the 
performance test requirement. This change resolves a point of confusion 
expressed by petitioners and aligns the regulatory text with the intent 
of the May 2024 rule as expressed in the preamble by clarifying that 
the performance test does not evaluate AEB activation timing. NHTSA 
also amends a test scenario in FMVSS No. 127 highlighted by petitioners 
that, when tested with very narrow vehicles at the extreme of the 
tolerances allowed by the test condition, resulted in a stringency 
beyond that intended by NHTSA. NHTSA makes that amendment to ensure the 
correct level of stringency. Petitioners also requested clarification 
of the specifications in FMVSS No. 127 for the FCW visual signal 
location. NHTSA amends the regulatory text to clarify these 
specifications. Petitioners also expressed concerns about the clarity 
and objectivity of the requirements and test conditions in FMVSS No. 
127 for the FCW audio signal. NHTSA clarifies these requirements by 
stating the location of the microphone and additional vehicle 
conditions under which testing will occur, as well as amending the 
definitions to simplify the requirement for suppression.
    Given the above, NHTSA finds that additional comment on the changes 
herein made in response to petitions for reconsideration of the May 
2024 final rule is unnecessary.
Congressional Review Act
    The Congressional Review Act, 5 U.S.C. 801 et. seq., as added by 
the Small Business Regulatory Enforcement Fairness Act of 1996, 
generally provides that before a rule may take effect, the agency 
promulgating the rule must submit a rule report, which includes a copy 
of the rule, to each House of the Congress and to the Comptroller 
General of the United States. NHTSA will submit a report containing 
this rule and other required information to the U.S. Senate, the U.S. 
House of Representatives, and the Comptroller General of the United 
States prior to publication of the rule in the Federal Register. This 
rule does not meet the criteria in 5 U.S.C. 804(2) to be considered a 
major rule.

V. Regulatory Text

List of Subjects in 49 CFR Part 571

    Motor vehicles, Motor vehicle safety, Rubber and rubber products.

[[Page 93220]]

    In consideration of the foregoing, NHTSA is amending 49 CFR part 
571 as set forth below.

PART 571--FEDERAL MOTOR VEHICLE SAFETY STANDARDS

0
1. The authority citation for part 571 continues to read as follows:

    Authority:  49 U.S.C. 322, 30111, 30115, 30117 and 30166; 
delegation of authority at 49 CFR 1.95.

0
2. Section 571.127 is amended by:
0
a. Removing the definition of ``masked threshold'' from S4;
0
b. Revising S5.1.1(a)(3) and (4), S5.1.1(b)(2), S5.1.3. and S8.3.3(g).
    The revisions read as follows:

Sec.  571.127  Standard No. 127; Automatic emergency braking systems 
for light vehicles.

* * * * *
    S5.1.1. * * *
    (a) * * *
    (3) The auditory signal as measured adjacent to a 50th percentile 
male driver's right ear (tragion) must have an intensity of 15-30 dB 
above the average noise level inside the vehicle when measured over a 
5-second period under the range of test conditions specified in S6, at 
100 km/h, with all vehicle openings closed, and all subject vehicle 
audio and sound-producing systems or functions that are not necessary 
for performing tests pursuant to the conditions in S6 and the 
procedures in S7, S8, S9 of this standard set to off.
    (4) In-vehicle audio that is not related to a crash avoidance 
system warning must be muted, or reduced in volume during presentation 
of the FCW auditory signal to within 5 dB of the average noise level 
inside the vehicle (as measured in S5.1.1(a)(3)), for the duration of 
the first between-pulse period of the FCW auditory signal under the 
range of test conditions specified in S6, at 100 km/h, with all vehicle 
openings closed, and all subject vehicle audio and sound-producing 
systems or functions that are not necessary for performing tests 
pursuant to the conditions in S6 and the procedures in S7, S8, S9 of 
this standard set to off.
    (b) * * *
    (1) The visual signal symbol must be located within an ellipse that 
extends 18 degrees vertically and 10 degrees 
horizontally of the driver forward line of sight based on the forward-
looking eye midpoint (Mf) as described in S14 of 49 CFR 
571.111.
* * * * *
    S5.1.3. Performance test requirements. The vehicle must provide a 
forward collision warning and subsequently apply the service brakes 
automatically such that the subject vehicle does not collide with the 
lead vehicle when tested using the procedures in S7 under the 
conditions specified in S6. The forward collision warning is not 
required if adaptive cruise control is engaged.
* * * * *
    S8.3.3. * * *
* * * * *
    (g) Two vehicle test devices are secured in stationary positions 
parallel to the intended travel path. The two vehicle test devices face 
the same direction as the intended travel path. One vehicle test device 
is directly behind the other separated by 1.0  0.1 m. The 
frontmost plane of the vehicle test device furthermost from the subject 
vehicle is located 1.0  0.1 m from the parallel contact 
plane (to the subject vehicle's frontmost plane) on the pedestrian test 
mannequin. The left side of each vehicle test device is no less than 
2.2 m to the right of the vertical plane through the intended travel 
path. The left side of each vehicle test device is no less than 1.15 m 
to the right of the vertical plane parallel to the plane through the 
intended travel path tangent to the 0 percent overlap point.
* * * * *

    Issued in Washington, DC, under authority delegated in 49 CFR 
1.95 and 49 CFR Part 501.
Jack Danielson,
Executive Director.
[FR Doc. 2024-27349 Filed 11-25-24; 8:45 am]
BILLING CODE 4910-59-P
```