`[Federal Register Volume 89, Number 232 (Tuesday, December 3, 2024)]
[Notices]
[Pages 95916-96083]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2024-27447]



[[Page 95915]]

Vol. 89

Tuesday,

No. 232

December 3, 2024

Part II





Department of Transportation





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National Highway Traffic Safety Administration





New Car Assessment Program Final Decision Notice--Advanced Driver 
Assistance Systems and Roadmap; Notice

  Federal Register / Vol. 89 , No. 232 / Tuesday, December 3, 2024 / 
Notices  

[[Page 95916]]


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DEPARTMENT OF TRANSPORTATION

National Highway Traffic Safety Administration

[Docket No. NHTSA-2024-0077]


New Car Assessment Program Final Decision Notice--Advanced Driver 
Assistance Systems and Roadmap

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

ACTION: Final decision notice.

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SUMMARY: This final decision notice adds four new advanced driver 
assistance systems (ADAS) technologies--blind spot warning (BSW), blind 
spot intervention (BSI), lane keeping assist (LKA), and pedestrian 
automatic emergency braking (PAEB)--to the New Car Assessment Program 
(NCAP) and enhances the performance evaluation of ADAS technologies 
currently in NCAP. The notice also finalizes a 10-year roadmap for 
updating NCAP through multiple phases for the period 2024 through 2033. 
This notice responds in part to the provisions in section 24213 of the 
Infrastructure, Investment, and Jobs Act.

DATES: Decisions on planned changes to the New Car Assessment Program 
are effective for the 2026 model year.

FOR FURTHER INFORMATION CONTACT: For technical issues, you may contact 
Ms. Taryn E. Rockwell, New Car Assessment Program, Office of 
Crashworthiness Standards (Telephone: (202) 366-1810). For legal 
issues, you may contact Ms. Sara R. Bennett, or Ms. Natasha D. Reed, 
Office of Chief Counsel (Telephone: (202) 366-2992). You may send mail 
to these officials at the National Highway Traffic Safety 
Administration, 1200 New Jersey Avenue SE, West Building, Washington, 
DC 20590-0001.

SUPPLEMENTARY INFORMATION: 

Table of Contents

I. Executive Summary
II. Summary of Updates to NCAP and Roadmap for Future Updates
III. Background
IV. Updating Forward Collision Prevention Technologies
V. Adding Pedestrian Automatic Emergency Braking (PAEB) Technology
VI. Adding Blind Spot Technologies
VII. Updating Lane Keeping Technologies
VIII. Self-Reported Data
IX. NCAP Roadmap
X. Economic Analysis
XI. Appendix

I. Executive Summary

    Since its launch in 1978, NHTSA's New Car Assessment Program (NCAP) 
has supported NHTSA's mission to reduce the number of fatalities and 
injuries that occur on U.S. roadways. NCAP, like many other NHTSA 
programs, has contributed to significant reductions in motor vehicle 
related crashes, fatalities, and injuries, with passenger vehicle 
occupant fatalities decreasing from 32,043 to 26,325 from 2001 to 
2021.\1\ Unfortunately, this reduction was not universal, with 
pedestrian fatalities increasing by 51 percent during the same 
timeframe, from 4,901 to 7,388.\2\ Despite improvements in automotive 
safety since NCAP's implementation, far more work must be done to 
reduce the continued high toll to human life on our nation's roads. In 
response to this need, on March 9, 2022, NHTSA published a Request for 
Comments (RFC) notice outlining proposed NCAP updates.\3\
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    \1\ Traffic Safety Facts 2021 ``A Compilation of Motor Vehicle 
Crash Data.'' U.S. Department of Transportation. National Highway 
Traffic Safety Administration. NHTSA acknowledges a recent increase 
in passenger vehicle occupant fatalities occurring during the COVID-
19 pandemic. In 2019, 22,372 passenger vehicle occupants were killed 
in traffic crashes.
    \2\ Traffic Safety Facts 2021 ``A Compilation of Motor Vehicle 
Crash Data.'' U.S. Department of Transportation. National Highway 
Traffic Safety Administration.
    \3\ Docket No. NHTSA-2021-0002. 87 FR 13452 (March 9, 2022).
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    After careful consideration of all comments received and applicable 
regulatory considerations, this notice announces the Agency's decision 
to update NCAP with the enhanced evaluation of advanced driver 
assistance systems (ADAS) technologies currently in NCAP \4\ and to add 
four new ADAS technologies to NCAP: blind spot warning (BSW), blind 
spot intervention (BSI), lane keeping assist (LKA),\5\ and pedestrian 
automatic emergency braking (PAEB). This notice also establishes a 10-
year roadmap for updating NCAP through a multi-phased approach, with 
RFC notices planned over the next several years. NHTSA will address 
comments received on program elements outside the scope of the March 
2022 RFC notice in subsequent final decision notices as part of the 
multi-phase efforts to update NCAP over the next several years.
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    \4\ The ADAS technologies currently evaluated in NCAP are 
forward collision warning (FCW), lane departure warning (LDW), 
dynamic brake support (DBS), and crash imminent braking (CIB).
    \5\ ``LKS'' was used for this technology in the March 2022 RFC. 
However, in this final decision notice, ``LKA'' is used instead to 
maintain consistency with other agency initiatives.
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A. Legal and Policy Considerations

    In finalizing its decisions for this notice, in addition to 
comments received, the Agency sought to address requirements from the 
2015 Fixing America's Surface Transportation (FAST) Act,\6\ the 2021 
Bipartisan Infrastructure Law (BIL), enacted as the Infrastructure 
Investment and Jobs Act,\7\ and the U.S. Department of Transportation's 
National Roadway Safety Strategy. The Agency also took into 
consideration its May 9, 2024, final rule for FMVSS No. 127, 
``Automatic Emergency Braking for Light Vehicles.'' \8\ These 
considerations are described below.
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    \6\ Public Law 114-94.
    \7\ Public Law 117-58.
    \8\ Docket No. NHTSA-2023-0021. 89 FR 39686 (May. 9, 2024).
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1. 2015 Fixing America's Surface Transportation Act

    This final decision notice serves as NHTSA's initial step in 
fulfilling section 24322 of the FAST Act, which directs the Agency to 
promulgate a rule ensuring the display of crash avoidance information 
next to crashworthiness information on window stickers that 
manufacturers place on motor vehicles.\9\ The Agency is currently 
working to develop a crash avoidance rating system based on comments 
received in response to several rating system concepts discussed in the 
March 2022 RFC, and this notice finalizes additional crash avoidance 
technologies that will be included in the future crash avoidance rating 
system.
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    \9\ Section 24322 of the FAST Act, otherwise known as the 
``Safety Through Informed Consumers Act of 2015.''
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2. 2021 Bipartisan Infrastructure Law

    This notice also fulfills in part several mandates in section 24213 
of the BIL, enacted on November 15, 2021 as the Infrastructure 
Investment and Jobs Act.\10\ First, section 24213(a) requires NHTSA to 
``finalize the proceeding for which comments were requested'' on 
December 16, 2015.\11\ This final decision notice does so by adopting 
four new ADAS technologies discussed in the Agency's December 16, 2015 
RFC notice,\12\ thus finalizing that proceeding and notice.\13\
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    \10\ Public Law 117-58.
    \11\ Id. at Section 24213(a); the notice referred to in the 
Bipartisan Infrastructure Law is 80 FR 78522 (Dec. 16, 2015).
    \12\ Docket No. NHTSA-2015-0119. 80 FR 78591 (Dec. 16, 2015).
    \13\ As communicated in the March 2022 RFC, while NHTSA is 
adopting a roadmap that includes aspects of the 2015 RFC, this 
notice is not an extension of the December 2015 notice.
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    Second, this notice addresses the Advanced Crash-Avoidance 
Technologies portion of section 24213(b) of the BIL, which directs the 
Secretary of the Department of

[[Page 95917]]

Transportation to ``publish a notice, for the purposes of public 
comment, to establish a means for providing consumer information 
relating to advanced crash-avoidance technologies'' within one year of 
enactment that includes an appropriate methodology for: (1) determining 
which advanced crash avoidance technologies should be included in the 
information, (2) developing performance test criteria for use by 
manufacturers in evaluating those technologies, (3) determining a 
distinct rating system involving each crash avoidance technology, and 
(4) updating overall vehicle ratings to incorporate the advanced crash 
avoidance technology ratings. This notice satisfies two of these four 
requirements by (1) adopting established criteria for determining which 
advanced crash avoidance technology \14\ should be included as 
referenced and discussed in the March 9, 2022 RFC notice, and (2) 
finalizing test procedures and criteria to evaluate performance for 
each of these advanced crash avoidance technologies. Although the 
Agency is not yet implementing a rating system for individual crash 
avoidance technologies, it has sought comments in this regard and has 
detailed plans in its roadmap to finalize such ratings, along with an 
updated overall (i.e., crashworthiness and crash avoidance) rating, in 
the near future.
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    \14\ This notice refers to advanced crash avoidance technology 
as ADAS technology.
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    Third, this notice addresses the Vulnerable Road User Safety 
portion of section 24213(b), which directs the Secretary to publish a 
notice meeting similar requirements to those mandated for advanced 
crash avoidance technologies ``to establish a means for providing to 
consumers information relating to pedestrian, bicyclist, or other 
vulnerable road user safety technologies'' within one year of 
enactment. By applying the established inclusion criteria in the 
adoption of PAEB technology and the applicable test procedures and 
evaluation criteria included in this notice, two of the four 
requirements for the Vulnerable Road User Safety portion of section 
24213(b) will be met. NHTSA will fulfill the remaining requirements 
when it proposes and finalizes a new rating system for the crash 
avoidance technologies in NCAP.
    Fourth, this final decision notice fulfills the requirements in 
section 24213(c) of the BIL. This section states that, within one year 
of the law's enactment, the Secretary of the Department of 
Transportation shall establish a roadmap, vetted through the public 
comment process, identifying and prioritizing safety opportunities and 
technologies that could be used in future roadmaps, establishing a plan 
for implementation of NCAP changes, and considering the benefits of 
consistency with other U.S. and international rating systems. Section 
24213(c) further specifies that the roadmap shall span a term of ten 
years, with five-year mid-term and five-year long-term components. 
Further, it requires updates to the roadmap at least once every four 
years to reflect new Agency interests and diverse stakeholder input 
(garnered annually), and in consideration of opportunities to benefit 
from collaboration and/or harmonization with third-party safety rating 
programs. As will be discussed herein, the Agency is taking steps to 
harmonize with existing consumer information rating programs, where 
possible and when appropriate, both for this NCAP update and future 
initiatives included in the program's roadmap. The Agency's proposed 
roadmap includes phased updates, as mandated, and was made available 
for public comment as part of the March 2022 RFC notice. As all 
relevant comments received have been considered prior to this notice's 
finalization, the Agency has fulfilled the requirements of section 
24213(c). Additional details for the mid-term and long-term five-year 
spans are available in the NCAP Roadmap section of this notice.

3. 2022 U.S. Department of Transportation National Roadway Safety 
Strategy (NRSS)

    The U.S. Department of Transportation published the National 
Roadway Safety Strategy (NRSS) in January 2022.\15\ The NRSS announced 
key planned departmental actions aimed at significantly reducing 
serious roadway injuries and deaths to reach the Department's long-term 
zero roadway fatalities goal. At the core of the NRSS is the 
Department-wide adoption of the Safe Systems Approach,\16\ which 
focuses on building layers of protection to both prevent crashes from 
happening and minimize harm when crashes do occur.
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    \15\ U.S. Department of Transportation. (2020). ``National 
Roadway Safety Strategy, Version 1.1.'' https://www.transportation.gov/sites/dot.gov/files/2022-02/USDOT-National-Roadway-Safety-Strategy.pdf.
    \16\ https://www.transportation.gov/NRSS/SafeSystem.
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    With respect to NCAP, the NRSS supports program updates emphasizing 
safety features that protect people both inside and outside the 
vehicle. These safety features may incorporate consideration of 
pedestrian protection systems, better understanding of impacts to 
pedestrians (e.g., specific considerations for children), and may 
include automatic emergency braking and lane keeping assistance to 
benefit bicyclists and pedestrians. The NCAP program also works to 
identify the most promising vehicle technologies to help achieve NRSS's 
safety goals, such as alcohol detection systems and driver distraction 
mitigation systems. In addition, the NRSS includes a 10-year roadmap 
for the program and lists as a key departmental action the initiation 
of rulemaking to update the vehicle Monroney label. As part of that 
process, the Agency may also consider including information on features 
that mitigate safety risks for people outside of the vehicle.
    This final decision notice presents NHTSA's initial actions towards 
the implementation of this broad, multi-faceted safety strategy for 
NCAP that includes improved road safety for both motor vehicle 
occupants and people outside of the vehicle, including pedestrians and 
other vulnerable road users. Additionally, the 10-year roadmap for the 
program presents a plan for the incorporation of future safety 
technologies and provides a projected timeline for updating the 
Monroney label to include crash avoidance information.
    Relatedly, NRSS lists the initiation of a new rulemaking to require 
automatic emergency braking and pedestrian automatic emergency braking 
on passenger vehicles as a key departmental action. In response to this 
action, NHTSA published a final rule on May 9, 2024, establishing a new 
Federal motor vehicle safety standard, FMVSS No. 127, ``Automatic 
Emergency Braking for Light Vehicles.'' Similar to the changes adopted 
by NCAP in this notice, this final rule aims to reduce the frequency 
and associated injury and fatalities of rear-end and pedestrian 
crashes. Manufacturers must comply with the final rule by September 1, 
2029.\17\ This final decision notice will upgrade NCAP to provide 
consumers with additional vehicle safety information on AEB and PAEB 
technologies to help them make more informed purchasing decisions. 
NHTSA will identify vehicles that are equipped with these recommended 
technologies and pass NHTSA's performance criteria by way of check 
marks on the NHTSA website starting with model year 2026

[[Page 95918]]

vehicles, as discussed in the following sections. Although the final 
rule and this decision on NCAP rely on the agency's separate 
authorities, NHTSA has sought to ensure that the revised test 
procedures for NCAP and the AEB final rule are compatible with one 
another, such that a manufacturer would be able to design a system that 
both received NCAP credit and would meet the requirements contained in 
the final rule.\18\ NHTSA believes these collective efforts will lead 
to more rapid and complete market penetration of AEB and PAEB 
technologies.
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    \17\ Vehicles produced by small-volume manufacturers, final-
stage manufacturers, and alterers must be equipped with a compliant 
AEB system by September 1, 2030.
    \18\ See Appendix.
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II. Summary of Updates to NCAP and Roadmap for Future Updates

    A brief summary of the updates to NCAP included in this final 
decision notice is provided below, along with the finalized 10-year 
roadmap for future updates to NCAP.

Updates To Crash Imminent Braking (CIB), Dynamic Brake Support (DBS), 
and Forward Collision Warning (FCW) Evaluations

    This notice modifies the existing test conditions, evaluation 
procedure, and performance criteria for crash imminent braking (CIB) 
and dynamic brake support (DBS) systems, subject to the same test 
scenarios currently used in NCAP.\19\ An overview of the amended test 
scenarios (Lead Vehicle Stopped (LVS), Lead Vehicle Moving (LVM), and 
Lead Vehicle Decelerating (LVD)) and test conditions (subject vehicle 
(SV) speed, principal other vehicle (POV) speed, POV headway, and POV 
deceleration) required to receive passing credit for AEB systems (i.e., 
CIB and DBS collectively) in NCAP is shown in Tables 1 and 2. NHTSA 
will test vehicles starting with the lowest test speed for a test 
scenario and incrementally increase test speed according to the test 
matrix in Tables 1 and 2, with only one trial \20\ conducted per test 
condition. The passing criterion for a test trial is no contact between 
the subject vehicle and principal other vehicle. If the subject vehicle 
contacts the principal other vehicle during a test trial, the vehicle 
fails the assessed test condition and the AEB test overall, whether CIB 
or DBS. In the event of subject vehicle-to-principal other vehicle 
contact, testing will cease for the test condition, respective test 
scenario, the AEB test being performed (i.e., CIB or DBS), and the AEB 
assessment overall.\21\ NHTSA will also continue to conduct the false 
positive \22\ test scenario currently used in NCAP, but has modified 
the test conditions and requirements for passing performance. This test 
scenario evaluates the propensity of a vehicle's DBS system to activate 
inappropriately in a non-critical driving scenario that would not 
present a safety risk to the vehicle's occupants. A vehicle must pass 
each of the 19 required CIB test conditions to obtain credit for CIB 
and must also separately pass each of the 17 required DBS test 
conditions to obtain credit for DBS.
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    \19\ CIB and DBS systems are collectively known as automatic 
emergency braking (AEB).
    \20\ Trial or test trial is a test among a set of tests 
conducted under the same test conditions (including test speed) with 
the same subject vehicle.
    \21\ In essence, because the Agency will provide an overall 
assessment for AEB performance, if a vehicle fails a trial run in 
the DBS test, testing will cease for the DBS assessment, and CIB 
assessments will not be conducted because the vehicle will have 
failed the AEB assessment overall.
    \22\ For purposes of this document, NHTSA uses ``false 
positive'' and ``false activation'' interchangeably, and the Agency 
intends for them to refer to the same situations.
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    NHTSA is consolidating forward collision warning (FCW) testing to 
assess and evaluate FCW functionality during CIB and DBS testing in all 
test scenarios except NHTSA's false positive tests. For evaluations 
during CIB and DBS testing, the test vehicle must issue an FCW prior to 
the onset of automatic braking (as defined by the instant the subject 
vehicle deceleration reaches at least 0.15g) for the vehicle to pass 
each test trial run conducted as part of NCAP's CIB and DBS testing. If 
the required FCW is not issued prior to the onset of automatic braking 
imparted by CIB, the vehicle will fail the test trial and CIB/DBS 
assessment overall. NHTSA will conduct the AEB evaluation by (1) fully 
releasing the subject vehicle's accelerator pedal (at any rate) within 
500 milliseconds (ms) after an FCW is issued (during CIB and DBS 
evaluations, and whether before or after automatic braking has begun), 
and (2) initiating manual (robotic) brake application at a time that 
corresponds to 1.0  0.1 seconds after issuance of the 
required FCW signals (during DBS evaluations). A FCW must be presented 
to the vehicle operator via a minimum of two sensory modalities to 
receive credit in each of NCAP's CIB and DBS tests (except for the 
false positive test). A vehicle must present, at a minimum, an FCW 
comprised of visual and auditory signals. Finally, Revision G of the AB 
Dynamics (ABD) Global Vehicle Target (GVT) will be used as the 
principal other vehicle in NCAP testing instead of the currently used 
Strikable Surrogate Vehicle (SSV) test device. Other details of the 
test conditions and response to comments on updating CIB, DBS, and FCW 
evaluations are provided in relevant sections in this notice.

                                                   Table 1--Adopted CIB Test Scenarios and Conditions
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                                                                                                                  POV
                 Test no.                    Test scenario   SV speed (kph  POV speed (kph  POV headway (m   deceleration        Requirement to pass
                                                                (mph))          (mph))          (ft.))            (g)
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1.........................................             LVS       40 (24.9)               0             n/a             n/a  No SV-to-POV contact during
                                                                                                                             any test trial.
2.........................................                       50 (31.1)               0             n/a             n/a
3.........................................                       60 (37.3)               0             n/a             n/a
4.........................................                       70 (43.5)               0             n/a             n/a
5.........................................                       80 (49.7)               0             n/a             n/a
6.........................................             LVM       40 (24.9)       20 (12.4)             n/a             n/a
7.........................................                       50 (31.1)       20 (12.4)             n/a             n/a
8.........................................                       60 (37.3)       20 (12.4)             n/a             n/a
9.........................................                       70 (43.5)       20 (12.4)             n/a             n/a
10........................................                       80 (49.7)       20 (12.4)             n/a             n/a
11........................................             LVD       50 (31.1)       50 (31.1)      40 (131.2)             0.3
12........................................                       50 (31.1)       50 (31.1)       12 (39.4)             0.3
13........................................                       80 (49.7)       80 (49.7)      40 (131.2)             0.3
14........................................                       80 (49.7)       80 (49.7)       12 (39.4)             0.3
15........................................                       50 (31.1)       50 (31.1)      40 (131.2)             0.5
16........................................                       50 (31.1)       50 (31.1)       12 (39.4)             0.5
17........................................                       80 (49.7)       80 (49.7)      40 (131.2)             0.5

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18........................................                       80 (49.7)       80 (49.7)       12 (39.4)             0.5
19........................................  False Positive       80 (49.7)             n/a             n/a             n/a  SV peak deceleration <0.25g
                                                     (STP)
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                                                   Table 2--Adopted DBS Test Scenarios and Conditions
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                                                                                                                  POV
                 Test no.                    Test scenario   SV speed (kph  POV speed (kph  POV headway (m   deceleration        Requirement to pass
                                                                (mph))          (mph))          (ft.))            (g)
--------------------------------------------------------------------------------------------------------------------------------------------------------
1.........................................             LVS       70 (43.5)               0             n/a             n/a  No SV-to-POV contact during
                                                                                                                             any test trial.
2.........................................                       80 (49.7)               0             n/a             n/a
3.........................................                       90 (55.9)               0             n/a             n/a
4.........................................                      100 (62.1)               0             n/a             n/a
5.........................................             LVM       70 (43.5)       20 (12.4)             n/a             n/a
6.........................................                       80 (49.7)       20 (12.4)             n/a             n/a
7.........................................                       90 (55.9)       20 (12.4)             n/a             n/a
8.........................................                      100 (62.1)       20 (12.4)             n/a             n/a
9.........................................             LVD       50 (31.1)       50 (31.1)      40 (131.2)             0.3
10........................................                       50 (31.1)       50 (31.1)       12 (39.4)             0.3
11........................................                       80 (49.7)       80 (49.7)      40 (131.2)             0.3
12........................................                       80 (49.7)       80 (49.7)       12 (39.4)             0.3
13........................................                       50 (31.1)       50 (31.1)      40 (131.2)             0.5
14........................................                       50 (31.1)       50 (31.1)       12 (39.4)             0.5
15........................................                       80 (49.7)       80 (49.7)      40 (131.2)             0.5
16........................................                       80 (49.7)       80 (49.7)       12 (39.4)             0.5
17........................................  False Positive       80 (49.7)             n/a             n/a             n/a  SV peak deceleration <0.25g
                                                     (STP)                                                                   over the baseline peak
                                                                                                                             imparted by manual braking.
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Adding Pedestrian Automatic Emergency Braking Evaluation

    NHTSA is adding the evaluation of pedestrian automatic emergency 
braking (PAEB) to NCAP using four crossing test scenarios and two in-
path test scenarios to evaluate PAEB in daylight and darkness lighting 
conditions with no overhead lights. For the crossing scenarios (S1), a 
walking adult or running child pedestrian mannequin crosses 
perpendicular to the vehicle's line of travel from either the driver's 
left or right side. For the in-path scenarios (S4), an adult pedestrian 
mannequin is slightly overlapped with the front of the vehicle and is 
either facing away while standing in front of the vehicle, or walking 
away from the vehicle, parallel to the flow of traffic.
    The subject vehicle's lower beam headlamps will be used during all 
NCAP PAEB testing in dark lighting conditions, and the upper beam 
headlamps will not be engaged either manually or automatically by way 
of an advanced lighting system, such as adaptive driving beams, unless 
such a system cannot be deactivated. This requirement will apply even 
to those systems that are active by default when low beam headlamps are 
first engaged. The performance criterion for NCAP's PAEB tests will be 
no contact with the pedestrian mannequin. The 4activePA Adult and 
4activePA Child pedestrian test mannequins (articulating mannequins) 
will be used for NCAP's PAEB evaluation.
    NHTSA will test for each of the adopted PAEB test conditions at a 
minimum subject vehicle speed threshold of 10 kph (6.2 mph), increasing 
the subject vehicle speed in 10 kph (6.2 mph) increments until the 
maximum speed threshold is reached, so long as the test vehicle does 
not contact the pedestrian mannequin during each progressive speed 
tested. For test conditions S1a, S1b, S1e, S4a, and S4c, the Agency is 
adopting a maximum subject vehicle speed threshold of 60 kph (37.3 mph) 
for both daylight and darkness testing. For test condition S1d, NHTSA 
is adopting a maximum subject vehicle speed threshold of 60 kph (37.3 
mph) for daylight testing and 40 kph (24.9 mph) for darkness testing. 
Should the subject vehicle contact the pedestrian mannequin during the 
initial run for any test speed, testing will cease for the test 
condition, respective test scenario, and PAEB testing overall for the 
particular lighting condition. Only one trial will be conducted per 
test condition and vehicles must pass all required tests (i.e., no 
contact with pedestrian mannequin) to receive PAEB credit for the 
relevant lighting condition.
    An overview of test scenarios and test parameters (pedestrian size, 
test speed, pedestrian motion, overlap, and obstruction) is provided in 
Tables 3 and 4.

                                                                Table 3--Adopted NCAP PAEB Daylight Test Conditions and Variants
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                                                                                                                                                                     Test speeds  (kph (mph))
          Test condition                    Size                Movement            Path  origin          Overlap  (%)           Obstruction         Test no.    -------------------------------
                                                             classification                                                                                             SV          Pedestrian
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S4c...............................  Adult (Facing Away).  Walk................  Right...............  25..................  No..................               1        10 (6.2)         5 (3.1)

[[Page 95920]]

 
                                                                                                                                                               2       20 (12.4)         5 (3.1)
                                                                                                                                                               3       30 (18.6)         5 (3.1)
                                                                                                                                                               4       40 (24.9)         5 (3.1)
                                                                                                                                                               5       50 (31.1)         5 (3.1)
                                                                                                                                                               6       60 (37.3)         5 (3.1)
S4a...............................  Adult (Facing Away).  Stationary..........  Right...............  25..................  No..................               7        10 (6.2)               0
                                                                                                                                                               8       20 (12.4)               0
                                                                                                                                                               9       30 (18.6)               0
                                                                                                                                                              10       40 (24.9)               0
                                                                                                                                                              11       50 (31.1)               0
                                                                                                                                                              12       60 (37.3)               0
S1b...............................  Adult...............  Walk................  Right...............  50..................  No..................              13        10 (6.2)         5 (3.1)
                                                                                                                                                              14       20 (12.4)         5 (3.1)
                                                                                                                                                              15       30 (18.6)         5 (3.1)
                                                                                                                                                              16       40 (24.9)         5 (3.1)
                                                                                                                                                              17       50 (31.1)         5 (3.1)
                                                                                                                                                              18       60 (37.3)         5 (3.1)
S1a...............................  Adult...............  Walk................  Right...............  25..................  No..................              19        10 (6.2)         5 (3.1)
                                                                                                                                                              20       20 (12.4)         5 (3.1)
                                                                                                                                                              21       30 (18.6)         5 (3.1)
                                                                                                                                                              22       40 (24.9)         5 (3.1)
                                                                                                                                                              23       50 (31.1)         5 (3.1)
                                                                                                                                                              24       60 (37.3)         5 (3.1)
S1e...............................  Adult...............  Run.................  Left................  50..................  No..................              25        10 (6.2)         8 (5.0)
                                                                                                                                                              26       20 (12.4)         8 (5.0)
                                                                                                                                                              27       30 (18.6)         8 (5.0)
                                                                                                                                                              28       40 (24.9)         8 (5.0)
                                                                                                                                                              29       50 (31.1)         8 (5.0)
                                                                                                                                                              30       60 (37.3)         8 (5.0)
S1d...............................  Child...............  Run.................  Right...............  50..................  Yes.................              31        10 (6.2)         5 (3.1)
                                                                                                                                                              32       20 (12.4)         5 (3.1)
                                                                                                                                                              33       30 (18.6)         5 (3.1)
                                                                                                                                                              34       40 (24.9)         5 (3.1)
                                                                                                                                                              35       50 (31.1)         5 (3.1)
                                                                                                                                                              36       60 (37.3)         5 (3.1)
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------


                                                                Table 4--Adopted NCAP PAEB Darkness Test Conditions and Variants
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                                                                                                                      Test speeds (kph (mph))
          Test condition                    Size                Movement            Path  origin          Overlap  (%)           Obstruction         Test no.    -------------------------------
                                                             classification                                                                                             SV          Pedestrian
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
S4c...............................  Adult (Facing Away).  Walk................  Right...............  25..................  No..................               1        10 (6.2)         5 (3.1)
                                                                                                                                                               2       20 (12.4)         5 (3.1)
                                                                                                                                                               3       30 (18.6)         5 (3.1)
                                                                                                                                                               4       40 (24.9)         5 (3.1)
                                                                                                                                                               5       50 (31.1)         5 (3.1)
                                                                                                                                                               6       60 (37.3)         5 (3.1)
S4a...............................  Adult (Facing Away).  Stationary..........  Right...............  25..................  No..................               7        10 (6.2)               0
                                                                                                                                                               8       20 (12.4)               0
                                                                                                                                                               9       30 (18.6)               0
                                                                                                                                                              10       40 (24.9)               0
                                                                                                                                                              11       50 (31.1)               0
                                                                                                                                                              12       60 (37.3)               0
S1b...............................  Adult...............  Walk................  Right...............  50%.................  No..................              13        10 (6.2)         5 (3.1)
                                                                                                                                                              14       20 (12.4)         5 (3.1)
                                                                                                                                                              15       30 (18.6)         5 (3.1)
                                                                                                                                                              16       40 (24.9)         5 (3.1)
                                                                                                                                                              17       50 (31.1)         5 (3.1)
                                                                                                                                                              18       60 (37.3)         5 (3.1)
S1a...............................  Adult...............  Walk................  Right...............  25..................  No..................              19        10 (6.2)         5 (3.1)
                                                                                                                                                              20       20 (12.4)         5 (3.1)
                                                                                                                                                              21       30 (18.6)         5 (3.1)
                                                                                                                                                              22       40 (24.9)         5 (3.1)
                                                                                                                                                              23       50 (31.1)         5 (3.1)
                                                                                                                                                              24       60 (37.3)         5 (3.1)

[[Page 95921]]

 
S1e...............................  Adult...............  Run.................  Left................  50..................  No..................              25        10 (6.2)         8 (5.0)
                                                                                                                                                              26       20 (12.4)         8 (5.0)
                                                                                                                                                              27       30 (18.6)         8 (5.0)
                                                                                                                                                              28       40 (24.9)         8 (5.0)
                                                                                                                                                              29       50 (31.1)         8 (5.0)
                                                                                                                                                              30       60 (37.3)         8 (5.0)
S1d...............................  Child...............  Run.................  Right...............  50..................  Yes.................              31        10 (6.2)         5 (3.1)
                                                                                                                                                              32       20 (12.4)         5 (3.1)
                                                                                                                                                              33       30 (18.6)         5 (3.1)
                                                                                                                                                              34       40 (24.9)         5 (3.1)
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
* All darkness testing to occur without the use of overhead artificial lighting.

Adding Blind Spot Warning (BSW) and Blind Spot Intervention (BSI) 
Evaluation

    This notice adds assessments for two blind spot technologies, BSW 
and BSI, to NCAP's crash avoidance program. Blind spot warning (BSW) 
and blind spot intervention (BSI) will be evaluated separately in 
individual tests conducted in daylight with the principal other vehicle 
on the left and right side of the subject vehicle, with the subject 
vehicle turn signal indicator activated and not activated. BSW will be 
evaluated using tests representing the Straight Lane Converge and 
Diverge and Straight Lane Pass-by scenarios,\23\ using an actual 
vehicle (representing a high production mid-size passenger car) as the 
principal other vehicle. For tests where the turn signal is not 
activated, a visual warning signal in the side mirror or the A-pillar 
must be issued within a specified time as detailed in the BSW test 
procedure. For tests where the turn signal is activated, an additional 
warning modality (i.e., a dual-modality warning) or an escalating 
visual warning signal (e.g., switches from steady-burning to flashing) 
is required within the time specified in the BSW test procedure.
---------------------------------------------------------------------------

    \23\ The two scenarios for assessing BSW were proposed in the 
March 2022 RFC notice and are described in a later section of this 
notice.
---------------------------------------------------------------------------

    For the BSW Straight Lane Converge and Diverge scenario, the test 
speed for both the subject vehicle and principal other vehicle will be 
72.4 kph (45.0 mph). For the BSW Straight Lane Pass-by scenario, NHTSA 
will conduct the lowest speed differential condition (subject vehicle/
principal other vehicle speeds of 72.4/80.5 kph (45.0/50.0 mph)) first. 
If the subject vehicle issues a passing BSW during the run, the 
principal other vehicle speed will be incrementally increased by 8.0 
kph (5.0 mph) and testing will continue with one run conducted per 
speed differential condition until a principal other vehicle speed of 
104.6 kph (65.0 mph) is reached. Testing will then be repeated 
following a similar methodology for principal other vehicle movement on 
the opposite side of the subject vehicle. If, for any speed 
differential condition, the subject vehicle does not issue a passing 
BSW, NHTSA will discontinue BSW testing for that vehicle model. Only 
one trial per BSW test condition will be conducted. An overview of the 
test scenarios and test parameters for the BSW tests is presented in 
Table 5. To obtain credit for BSW, the vehicle must pass all 20 tests 
for BSW.

                            Table 5--Blind Spot Warning (BSW) Adopted Test Conditions
----------------------------------------------------------------------------------------------------------------
                                     SV speed (kph  POV speed (kph     POV direction of
           Test scenario                (mph))          (mph))             approach             Turn signal
----------------------------------------------------------------------------------------------------------------
Straight Lane.....................       72.4 (45)       72.4 (45)  Right................  Enabled
Converge and Diverge..............                                                         Disabled
                                                                    Left.................  Enabled
                                                                                           Disabled
Straight Lane Pass-by.............       72.4 (45)       80.5 (50)  Right................  Enabled
                                                                                           Disabled
                                                                    Left.................  Enabled
                                                                                           Disabled
                                                         88.5 (55)  Right................  Enabled
                                                                                           Disabled
                                                                    Left.................  Enabled
                                                                                           Disabled
                                                         96.6 (60)  Right................  Enabled
                                                                                           Disabled
                                                                    Left.................  Enabled
                                                                                           Disabled
                                                        104.6 (65)  Right................  Enabled
                                                                                           Disabled
                                                                    Left.................  Enabled
                                                                                           Disabled
----------------------------------------------------------------------------------------------------------------


[[Page 95922]]

    BSI will be evaluated using tests representing two lane change 
scenarios (Subject Vehicle Lane Change with Constant Headway and 
Subject Vehicle Lane Change with Closing Headway) and one false 
positive scenario (Subject Vehicle Lane Change with Constant Headway 
False Positive Assessment),\24\ using Revision G of the ABD GVT as the 
principal other vehicle. All BSI evaluations will be conducted with 
adaptive cruise control (ACC), lane centering assistance (LCA), and/or 
lane keeping assist (LKA) technologies (if equipped and if the systems 
can be disengaged) turned off.
---------------------------------------------------------------------------

    \24\ These three scenarios for assessing BSI were proposed in 
the March 2022 RFC notice and are described in a later section of 
the notice.
---------------------------------------------------------------------------

    For the BSI Subject Vehicle Lane Change with Constant Headway and 
the False Positive tests, the test speed for both the subject vehicle 
and principal other vehicle will be 72.4 kph (45.0 mph). For the BSI 
Subject Vehicle Lane Change with Closing Headway tests, the subject 
vehicle test speed will be 72.4 kph (45.0 mph) and the principal other 
vehicle speed will be 80.5 kph (50 mph). In these tests, after a short 
period of steady-state driving, the subject vehicle driver (i.e., 
robot) initiates a lane change and follows an 800 m (2,625 ft.) radius 
curved path towards the principal other vehicles' travel lane. The 
subject vehicle driver then releases the steering wheel upon the 
subject vehicle exiting the curve so as to achieve a steady state 
lateral velocity of 0.7  0.1 m/s (2.3  0.3 ft./
s) relative to the line separating the subject vehicle and principal 
other vehicle travel lanes. Each test scenario is conducted with turn 
signal enabled and disabled and for both left and right lane change 
directions.
    To pass the Subject Vehicle Lane Change with Constant Headway and 
the Subject Vehicle Lane Change with Closing Headway tests, the BSI 
system must prevent any contact between the subject vehicle and the 
principal other vehicle. The subject vehicle BSI intervention must not 
cause a secondary departure on the opposite side of the lane. To pass a 
false positive test, the BSI system must not intervene. Only one trial 
per BSI test condition will be conducted. An overview of the test 
scenarios and test parameters for the BSI tests is presented in Table 
6. To obtain credit for BSI, the vehicle must pass all 12 tests.

                         Table 6--Blind Spot Intervention (BSI) Adopted Test Conditions
----------------------------------------------------------------------------------------------------------------
                                              SV speed    POV speed   Lane change
               Test scenario                (kph (mph))  (kph (mph))   direction            Turn signal
----------------------------------------------------------------------------------------------------------------
SV Lane Change with Constant Headway......    72.4 (45)    72.4 (45)         Left  Enabled.
                                                                                   Disabled.
                                            ...........  ...........        Right  Enabled.
                                                                                   Disabled.
SV Lane Change with Closing Headway.......    72.4 (45)    80.5 (50)         Left  Enabled.
                                                                                   Disabled.
                                            ...........  ...........        Right  Enabled.
                                                                                   Disabled.
SV Lane Change with Constant Headway,         72.4 (45)    72.4 (45)         Left  Enabled.
 False Positive Assessment.                                                        Disabled.
                                            ...........  ...........        Right  Enabled.
                                                                                   Disabled.
----------------------------------------------------------------------------------------------------------------

Adding Lane Keeping Assist (LKA) and Enhancing Lane Departure Warning 
(LDW) Evaluation

    NHTSA is adding the assessment of lane keeping assist (LKA) into 
NCAP and integrating the evaluation of lane departure warning (LDW) 
with the LKA evaluation. To evaluate a vehicle's LDW sensitivity and 
LKA intervention capabilities, NHTSA's testing includes the use of a 
single solid white lane line, dashed yellow lane line, or Botts' dots 
(raised pavement markers) on either the right or left side of the 
vehicle's travel lane, depending on testing direction. Additional tests 
will be conducted with two lane lines (solid yellow and dashed white 
lines, and dashed white and solid white lines) to evaluate a vehicle's 
ability to properly correct its heading to prevent a secondary lane 
departure after the initial intervention. For the LDW/LKA tests, the 
subject vehicle, traveling at a speed of 72.4 kph (45 mph), heads 
towards the lane line using an initial path defined by a 1,200 m (3,937 
ft.) radius curve. Tests will be conducted by incrementing the lateral 
velocity of the subject vehicle's approach toward the lane line from 
0.2 to 0.6 m/s (0.7 to 2.0 ft./s) in 0.1 m/s (0.3 ft./s) increments.
    To pass the criteria of the LDW/LKA evaluation test, the subject 
vehicle must issue a visual signal when the lateral position of the 
vehicle, represented by a two-dimensional polygon, is within 0.75 m 
(2.5 ft.) of the inboard edge of the lane line and before the lane 
departure exceeds 0.3 m (1 ft.). The LKA intervention itself will serve 
as a secondary haptic alert component. Neither an LDW nor LKA 
intervention shall occur when a vehicle has not departed its lane and 
is farther than 0.75 m (2.5 ft.) from the inboard edge of the lane 
line. In addition, the visual warning signal and LKA intervention must 
be issued before the lane departure exceeds 0.3 m (1 ft.), and the 
visual alert must be issued prior to, or concurrent with, the start of 
the LKA intervention. Only one trial per test condition is conducted. 
An overview of the test scenarios and test parameters for the LDW/LKA 
tests is presented in Table 7. To obtain credit for LDW and LKA, the 
vehicle must pass all 50 tests performed during the LDW/LKA performance 
assessment.

[[Page 95923]]



                                 Table 7--Lane Departure Warning (LDW)/Lane Keeping Assist (LKA) Adopted Test Conditions
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                                                                   Passing criteria
                                                                    Departure     Lateral   ------------------------------------------------------------
             Test scenario                      Line type           direction   velocity (m/  Maximum SV  excursion
                                                                                 s (ft./s))         (m (ft.))             LDW alert issued (m (ft.))
--------------------------------------------------------------------------------------------------------------------------------------------------------
Primary Departure.....................  Solid White..............         Left    0.2 (0.7)              -0.3 (-1.0)                        0.75 to -0.3
(Single Straight Lane Line)...........                                            0.3 (1.0)                                               (2.5 to -1.0).
                                                                                  0.4 (1.3)
                                                                                  0.5 (1.6)
                                                                                  0.6 (2.0)
                                        Solid White..............        Right    0.2 (0.7)
                                                                                  0.3 (1.0)
                                                                                  0.4 (1.3)
                                                                                  0.5 (1.6)
                                                                                  0.6 (2.0)
                                        Dashed Yellow............         Left    0.2 (0.7)
                                                                                  0.3 (1.0)
                                                                                  0.4 (1.3)
                                                                                  0.5 (1.6)
                                                                                  0.6 (2.0)
                                        Dashed Yellow............        Right    0.2 (0.7)
                                                                                  0.3 (1.0)
                                                                                  0.4 (1.3)
                                                                                  0.5 (1.6)
                                                                                  0.6 (2.0)
                                        Raised Pavement Markers..         Left    0.2 (0.7)
                                                                                  0.3 (1.0)
                                                                                  0.4 (1.3)
                                                                                  0.5 (1.6)
                                                                                  0.6 (2.0)
                                        Raised Pavement Markers..        Right    0.2 (0.7)
                                                                                  0.3 (1.0)
                                                                                  0.4 (1.3)
                                                                                  0.5 (1.6)
                                                                                  0.6 (2.0)
Secondary Departure...................  Solid Yellow (L)/Dashed           Left    0.2 (0.7)              -0.3 (-1.0)                        0.75 to -0.3
(Dual Straight Lane Line).............   White (R).                               0.3 (1.0)                                               (2.5 to -1.0).
                                                                                  0.4 (1.3)
                                                                                  0.5 (1.6)
                                                                                  0.6 (2.0)
                                        Solid Yellow (L)/Dashed          Right    0.2 (0.7)
                                         White (R).                               0.3 (1.0)
                                                                                  0.4 (1.3)
                                                                                  0.5 (1.6)
                                                                                  0.6 (2.0)
                                        Dashed White (L)/Solid            Left    0.2 (0.7)
                                         White (R).                               0.3 (1.0)
                                                                                  0.4 (1.3)
                                                                                  0.5 (1.6)
                                                                                  0.6 (2.0)
                                        Dashed White (L)/Solid           Right    0.2 (0.7)
                                         White (R).                               0.3 (1.0)
                                                                                  0.4 (1.3)
                                                                                  0.5 (1.6)
                                                                                  0.6 (2.0)
--------------------------------------------------------------------------------------------------------------------------------------------------------

NCAP Roadmap 2024-2033

    NHTSA has developed a final roadmap to update NCAP through multiple 
phases from 2024 through 2033, with mid-term roadmap items spanning the 
period 2024-2028, and long-term items spanning the period 2024-2033. 
The NCAP roadmap includes four phases for each NCAP initiative, along 
with a completion milestone for each phase. The four phases are: (1) 
Research phase, if applicable, (2) Request for comment (RFC) phase, (3) 
Final decision phase, and (4) Implementation phase. NHTSA plans updates 
to NCAP in the following three safety programs: crashworthiness, crash 
avoidance, and vulnerable road user safety. A summary of the mid-term 
and long-term actions for this roadmap is presented in Tables 8 and 9, 
respectively. The timeframe shown for the research, RFC, and final 
decision phases is in calendar years. The start of the implementation 
phase is in the fourth quarter of the calendar year shown in the two 
tables. Note that the implementation phase starts with vehicle models 
of the following calendar year shown in Tables 8 and 9. NHTSA plans to 
update the NCAP roadmap approximately every four years, with timelines 
updated accordingly. Details of the NCAP roadmap are provided in the 
roadmap section of this notice.

[[Page 95924]]



                                 Table 8--Roadmap for Mid-Term Upgrades to NCAP
                                               [In calendar years]
----------------------------------------------------------------------------------------------------------------
                                                                                      Final      Implementation
         Potential updates to NCAP evaluations             Research    RFC phase     decision    phase start in
                                                            phase                     phase        4th quarter
----------------------------------------------------------------------------------------------------------------
Crash Avoidance Program:
    Enhanced FCW, CIB, DBS.............................  ...........  ...........    2023-2024              2025
    LDW+LKA and BSW+BSI................................  ...........  ...........    2023-2024              2025
    Rear Automatic Braking.............................         2024         2025    2025-2026              2027
Crashworthiness Program:
    THOR-50M in Frontal Crash Tests and HIII-05F * in           2024    2024-2025    2025-2026              2027
     Driver Position in Frontal Rigid Barrier Crash
     Test..............................................
    Frontal Oblique Crash Test with THOR-50M...........         2024    2024-2025    2025-2026              2027
    WorldSID-50M in Side Impact Tests, and SID-IIs **           2024    2024-2025    2025-2026              2027
     Rib Deflections for Injury Risk Assessment........
Vulnerable Road User (VRU) Safety Program:
    PAEB (day and night-time)..........................  ...........  ...........    2023-2024              2025
    Crashworthiness Pedestrian Protection..............  ...........  ...........    2023-2024              2025
    Unattended Child Alert System (Availability of       ...........  ...........  ...........              2024
     Direct Sensing Technologies Noted in Safety
     Features Section on Ratings Webpage)..............
    Bicyclist and Motorcyclist AEB (along path             2024-2025         2025    2025-2026              2027
     scenarios)........................................
Vehicle Safety Rating:
    Rating System for Crash Avoidance Technologies.....  ...........  ...........    2024-2025              2027
    Rating Systems for Crashworthiness, VRU Safety, and  ...........    2024-2025    2025-2026              2027
     Overall Safety....................................
    Monroney Label Rulemaking--Crash Avoidance,            2023-2024         2025    2025-2026              2027
     Crashworthiness, VRU Safety, and Overall Safety
     Ratings...........................................
----------------------------------------------------------------------------------------------------------------
* The advanced 5th percentile female frontal impact test dummy, THOR-05F, is currently under evaluation/
  refinement and is included in the long-term NCAP update in this roadmap. Until THOR-05F is completed and
  included in NCAP, NHTSA will use the current HIII-05F dummy in frontal crash tests.
** The advanced 5th percentile female side impact test dummy, WorldSID-05F, is currently under development and
  its use in NCAP will be considered in the long-term section of this roadmap. Until WorldSID-05F is included in
  NCAP, the SID-IIs will be used in NCAP along with thoracic and abdominal deflection measurements.


                                 Table 9--Roadmap for Long-Term Upgrades to NCAP
                                               [In calendar years]
----------------------------------------------------------------------------------------------------------------
                                                                                      Final      Implementation
         Potential updates to NCAP Evaluations             Research    RFC phase     decision    phase start in
                                                            phase                     phase        4th quarter
----------------------------------------------------------------------------------------------------------------
Crash Avoidance Program:
    Headlighting System (Advanced Driving Beam, Semi-      2024-2026    2026-2027         2028              2030
     Automatic Beam Switching, and Lower Beam Headlamp)
    AEB for Intersection Crash Scenarios...............    2025-2027         2028         2029              2031
    Enhanced LKA (Higher Speed, Curved Road and/or Road    2024-2026         2027         2028              2030
     Edge Detection Scenarios).........................
    Enhanced AEB (Speed and Additional Scenarios)......    2026-2028         2029         2030              2032
    Driver Monitoring Systems--Distracted/Drowsy           2023-2027         2028         2029              2031
     Driving...........................................
    Intelligent Speed Assist...........................    2024-2028
Crashworthiness Program:
    THOR-05F in Frontal Crash Tests in Front and Rear      2023-2027    2027-2028    2028-2029              2031
     Seating Positions.................................
    WorldSID-05F in Side Impact Crash Tests............    2023-2029    2029-2030    2030-2031              2033
VRU Safety Program:
    Enhanced AEB for Bicyclists and Motorcyclists in       2025-2026         2027         2028              2030
     Intersection Crashes..............................
    BSW and BSI Evaluation for Bicyclists and              2025-2026         2027         2028              2030
     Motorcyclists Crash Protection....................
    Crashworthiness Pedestrian Protection using aPLI *.    2024-2025         2026         2027              2029
    Enhanced PAEB (Speed and Additional Scenarios).....    2026-2028         2029         2030              2032
    Driver Visibility..................................    2023-2027
----------------------------------------------------------------------------------------------------------------
* aPLI is the advanced pedestrian legform impactor. It assesses pedestrian injuries to the knee, upper leg, and
  lower leg in impacts with the front of vehicles.

III. Background

    The National Highway Traffic Safety Administration's (NHTSA's) New 
Car Assessment Program (NCAP) supports the Agency's mission to reduce 
the number of fatalities and injuries that occur on U.S. roadways by 
providing important vehicle safety information to consumers to inform 
their purchasing decisions. The last major NCAP upgrade occurred on 
July 11, 2008, and took effect with model year 2011 vehicles.\25\ That 
program update included the Agency's adoption of new frontal and side 
anthropomorphic test devices (crash test dummies) and associated injury 
criteria, a new oblique side pole test, and a new overall rating system 
combining the individual frontal, side, and rollover ratings. NHTSA 
also expanded NCAP to include assessment of three advanced driver 
assistance systems (ADAS) technologies: forward collision warning 
(FCW), lane departure warning (LDW), and electronic stability

[[Page 95925]]

control (ESC).\26\ Through that expansion, the Agency began to identify 
which vehicles were equipped with these technologies and met specified 
performance requirements, making this information available on the 
NHTSA website. In November 2015, NHTSA also added crash imminent 
braking (CIB) and dynamic brake support (DBS) technologies (also known 
as automatic emergency braking, or AEB technology) to its ADAS 
assessments, with implementation beginning with model year 2018 
vehicles.\27\
---------------------------------------------------------------------------

    \25\ 73 FR 40016 (July 11, 2008).
    \26\ ESC was removed from the Agency's list of recommended ADAS 
technologies through NCAP beginning in model year 2014 when the 
technology became mandated under Federal motor vehicle safety 
standard (FMVSS) No. 126, ``Electronic stability control.'' NHTSA 
also included rear video systems in its list of recommended 
technologies under NCAP from model years 2014 to 2017 and removed 
that technology from its list when it became mandated under FMVSS 
No. 111, ``Rear visibility.''
    \27\ 80 FR 68604 (Nov. 5, 2015).
---------------------------------------------------------------------------

    In December 2015, the Agency published a Request for Comments (RFC) 
notice with planned changes to the overall NCAP program. The notice 
sought comment on NCAP's potential use of enhanced tools and techniques 
to evaluate the safety of vehicles, generate star ratings, and 
encourage further vehicle safety developments.\28\ The RFC notice also 
outlined planned changes for the crashworthiness, crash avoidance, and 
ratings categories. Many commenters responding to the December 2015 RFC 
notice stated it lacked sufficient detail and supporting information to 
allow for thorough review and comment. Commenters also expressed 
concern over test procedure repeatability and reproducibility based on 
the RFC notice's lack of detail, performance criteria, and non-
standardized test devices. NHTSA hosted a public meeting in October 
2018 to re-engage stakeholders and seek up-to-date input to help the 
Agency plan the future of NCAP.
---------------------------------------------------------------------------

    \28\ 80 FR 78521 (Dec. 16, 2015).
---------------------------------------------------------------------------

    On March 9, 2022, NHTSA published an RFC notice proposing changes 
to NCAP in response to the comments received from the 2015 RFC and 
public meetings, which partially fulfills the Agency's obligations 
under the 2015 Fixing America's Surface Transportation (FAST) Act 
directive and recent mandates included in section 24213 of the November 
2021 Bipartisan Infrastructure Law (BIL). The proposed changes include:
     Changes to test procedures and performance criteria, 
including an increase in stringency, for the four currently recommended 
ADAS technologies in NCAP (FCW, LDW, DBS, and CIB) to enhance 
evaluation of the systems' capabilities in current vehicle models, 
reduce test burden, and promote harmonization with other consumer 
information programs.
     The addition of four new ADAS technologies--blind spot 
warning (BSW), blind spot intervention (BSI), lane keeping assist 
(LKA), and pedestrian automatic emergency braking (PAEB)--to those 
currently recommended by NCAP and highlighted on the Agency's website. 
The Agency proposed to incorporate these four new ADAS technologies 
into NCAP because data indicates they satisfy NHTSA's four 
prerequisites for inclusion in the program: (1) a known safety need 
exists; (2) system designs (countermeasures) exist that can mitigate 
the safety problem; (3) existing or new system designs have the 
potential to improve safety; and (4) a performance-based objective test 
procedure exists that can assess system performance.\29\
---------------------------------------------------------------------------

    \29\ See NCAP Rating FAQ No. 07, http://nhtsa.gov/ratings.
---------------------------------------------------------------------------

     A ``roadmap'' of the Agency's plans to update NCAP in 
phases over the next ten years, setting forth NHTSA's mid-term and 
long-term strategies for upgrading the program using a phased approach. 
The roadmap presents an estimated timeframe for the issuance of phased 
request for comment notices to incorporate various potential program 
components. However, NHTSA would only issue proposals to update the 
program as technologies mature and are considered ready for inclusion 
such that they meet the program's four prerequisites. Following each 
proposal, NHTSA will issue a final decision notice responding to the 
comments received and providing the Agency's decisions for that 
particular program update, as well as the lead time for implementation.
    In addition to these proposed changes, the RFC notice proposed 
operational changes to streamline the information provided to 
consumers. Specifically, the Agency proposed a process for updating 
ADAS-related information provided to consumers to reflect changes made 
to vehicles during the middle of a model year. Further, although not 
explicitly proposed in the RFC notice, the Agency sought comment on the 
following topics to help guide future proposals:
     The Agency's plan to develop a new ADAS rating system for 
NCAP to provide consumers with improved data to compare and shop for 
vehicles and spur improved ADAS performance. NCAP currently assigns 
ratings to vehicles based on their performance in crashworthiness 
(i.e., frontal and side impact) and rollover tests, but the program has 
no complementary rating system to differentiate performance among 
vehicles' crash avoidance systems. Instead, NCAP only recommends 
certain ADAS technologies to shoppers and identifies vehicles that 
offer the recommended technologies that pass the program's system 
performance criteria.
     Steps to include crash avoidance rating information on a 
vehicle's window sticker (i.e., the Monroney label) at the point of 
sale, consistent with the 2015 FAST Act. The Agency noted that it is 
currently conducting consumer research to determine how best to present 
such information to maximize its effectiveness in informing vehicle 
purchasing decisions. NHTSA stated that it would consider the 
information gained from this research in conjunction with related 
comments received in response to the 2022 RFC to develop a proposal for 
a revised label, which will be detailed in a separate RFC notice.
     Expanding NCAP to include safety technologies that promote 
NHTSA's continuing efforts to combat unsafe driving or riding 
behaviors, such as speeding and drowsy, impaired, distracted, and 
unbelted driving, as well as safety technologies that may prevent 
unintentional human behavior that may result in injury or death, such 
as vehicular heatstroke.
     The Agency's ideas for updating several programmatic 
aspects of NCAP, including adding new crash test dummies, updating the 
rollover risk curve, and enhancing the presentation and dissemination 
of safety information provided to consumers to improve the program. 
More specifically, NHTSA requested comment on several potential ways to 
revise the 5-star safety ratings system, including adopting a points-
based rating system concept, revising the baseline risk, and 
incorporating decimal or half-star ratings.
     Additional considerations that would allow NCAP to remain 
effective and relevant to improve vehicle safety, such as proposed 
updates to the NCAP website and the development of an NCAP database to 
modernize the operational aspects of the program, including a new 
vehicle information submission process for vehicle manufacturers.
    Following publication of the March 2022 RFC notice, NHTSA received 
comments generally supportive of the Agency's proposal to adopt 
additional crash avoidance elements. Additional details of NHTSA's 
proposal for each of

[[Page 95926]]

the items listed above is provided in later sections.
Summary of General Comments on Proposed Updates to NCAP
    NHTSA received over 4,000 comments in response to the March 2022 
RFC notice.\30\ The Agency received comments from a wide variety of 
commenters including safety advocacy groups, trade associations, 
vehicle manufacturers, suppliers and developers, government agencies 
and associations, test laboratories, an insurance company, a research/
consulting firm, and individual members of the public. A summary of the 
commenters to the March 2022 RFC notice is provided in Table 10.
---------------------------------------------------------------------------

    \30\ The March 2022 RFC notice requested comment on a number of 
topics, including emerging technologies, and potential future 
updates to NCAP, that have not been proposed, and thus are not 
addressed, in the present notice. Details of the comments received 
and the Agency's response to these comments will be provided in 
future RFC notices relevant to those topics.

         Table 10--Commenters to the March 2022 NCAP RFC Notice
------------------------------------------------------------------------
           Category                            Commenters
------------------------------------------------------------------------
Safety Advocacy Groups.......  AAA Inc. (AAA), AARP, Advanced Mobility
                                Group, Advocates for Highway and Auto
                                Safety (Advocates), American
                                Motorcyclist Association (AMA), Center
                                for Auto Safety (CAS), Consortium for
                                Constituents with Disabilities
                                Transportation Task Force (CCD
                                Transportation Task Force), Consumer
                                Reports (CR), Insurance Institute for
                                Highway Safety (IIHS), Kids and Car
                                Safety (KAC), Families for Safe Streets
                                (FSS), Intelligent Transportation
                                Society of America (ITS America),
                                Massachusetts Vision Zero Coalition, The
                                League of American Bicyclists (The
                                League), Vision Zero Network (VZN), and
                                ZF Group.
Industry Trade Associations..  Alliance for Automotive Innovation (Auto
                                Innovators), Automotive Safety Council
                                (ASC), Motor & Equipment Manufacturers
                                Association (MEMA), Motorcycle Industry
                                Council and Motorcycle Safety Foundation
                                (MIC/MSF), National Automobile Dealers
                                Association (NADA), Specialty Equipment
                                Market Association (SEMA), The Lidar
                                Coalition.
Vehicle Manufacturers........  American Honda Motor Co., Inc. (Honda),
                                BMW of North America, LLC (BMW), FCA US
                                LLC (FCA), Ford Motor Company (Ford),
                                General Motors (GM), Hyundai America
                                Technical Center, Inc. (HATCI), Hyundai
                                Motor North America (Hyundai), Mercedes-
                                Benz, LLC, a division of Mercedes-Benz
                                Automotive Group (Mercedes-Benz), North
                                American Subaru, Inc. (Subaru), Rivian
                                Automotive, LLC (Rivian), Tesla, Inc.
                                (Tesla), Toyota Motor North America
                                (Toyota).
Suppliers and Developers.....  Aptiv PLC (Aptiv), Bosch LLC (Bosch),
                                DENSO Corporation (DENSO), Intel
                                Corporation (Intel), Robert Vayyar,
                                Velodyne Lidar, Inc. (Velodyne).
Government Agencies and        American Association of State Highway and
 Associations.                  Transportation Officials (AASHTO),
                                National Association of City
                                Transportation Officials (NACTO),
                                National Transportation Safety Board
                                (NTSB), New York City Department of
                                Transportation & New York City
                                Department of Citywide Administrative
                                Services, Vision Zero Task Force (NYC
                                DOT/NYC DCAS, Vision Zero Task Force).
Test Laboratories............  Applus IDIADA (IDIADA), Dynamic Research
                                Inc. (DRI), Transportation Research
                                Center, Inc. (TRC).
Insurance Companies..........  State Farm Insurance Companies (State
                                Farm).
Research/Consulting Companies  Safe Streets Research & Consulting (Safe
                                Streets).
General Public...............  Individuals.
------------------------------------------------------------------------

    Many commenters stated they support NHTSA's goal of providing 
comparative safety information to consumers through NCAP but encouraged 
the Agency to further leverage NCAP to ensure consumers have a 
comprehensive understanding of vehicle safety. Commenters also stated 
that more testing, rating, and information-sharing with consumers about 
the functionalities of advanced safety technologies via NCAP will 
promote the technologies' use in future vehicles and advance vehicle 
safety. The Alliance for Automotive Innovation (Auto Innovators) stated 
it supports NHTSA's efforts to modernize NCAP, noting that a key 
benefit of a well-developed and technically robust NCAP is the 
introduction of advanced safety technologies and performance evaluation 
through market incentives (objective ratings) in a structured and 
predictable manner via the development of testing procedures, 
evaluation metrics, and safety benefits. Auto Innovators stated that 
doing so will lead to more vehicles being equipped with new ADAS 
technologies, ultimately decreasing technology costs, and bolstering 
the case for potential regulation.
    Many commenters, including those who have lost loved ones in 
automotive accidents, expressed support for the proposed NCAP changes 
but stated they do not go far enough, noting the U.S. program is behind 
other countries' NCAP programs in updating, implementing, and 
``standardizing'' NCAP with proven safety technologies to save more 
lives. The Advocates for Highway and Auto Safety (Advocates), the 
Consumer Federation of America, and many others expressed concern that 
the approach described in the March 2022 RFC is not sufficiently 
specific and lacks firm commitments on key updates to the program. 
Further, the National Safety Council (NSC) stated that its data 
continues to suggest NHTSA is not doing enough to address roadway 
safety, with thousands of people dying in preventable crashes each 
year.
    Several commenters pointed out that fatalities involving 
pedestrians and cyclists have been increasing at alarming rates and 
urged NHTSA to consider the safety of those outside of the vehicle. 
Many cyclist organizations stated that any NCAP updates should include 
cyclist AEB testing and tests aimed at increasing cyclist safety. One 
individual noted the more than 50 percent increase in annual pedestrian 
fatalities in the past decade, stating that safety innovations are 
benefiting those inside, not outside, of the vehicle. Many other 
individual commenters expressed concern for the safety of pedestrians, 
mobility device users, and cyclists amidst rising fatalities from 
increasingly large vehicles, suggesting that NHTSA should consider 
promoting technologies and performing tests to protect them.
    Many commenters expressed support for the Agency's proposed 
inclusion of the four new ADAS technologies and for enhancing the 
evaluation of ADAS technologies currently in NCAP. However, some 
commenters argued the proposal did not go far enough, suggesting that 
ADAS technologies (including PAEB) should not just be part of the 
voluntary NCAP program but should be mandatory on new vehicles to 
reduce fatalities, especially in urban areas. Many commenters also 
requested that NHTSA harmonize test procedures and evaluations with 
other existing testing protocols like Euro NCAP. While commenters 
generally supported the proposed roadmap, some noted that it

[[Page 95927]]

lacked sufficient specificity on future timelines, dates, and required 
actions. Commenters requested periodic stakeholder engagement and 
collaboration for developing future NCAP roadmaps.
    Several commenters also provided detailed responses to questions 
NHTSA posed in the March 2022 RFC notice to help guide its decisions. 
The following sections discuss in detail: (1) NHTSA's proposal for each 
technology, (2) the Agency's response to the comments received to the 
questions posed, and (3) final decisions on the proposed changes to 
NCAP specific to the technology.

IV. Updating Forward Collision Prevention Technologies

    NHTSA is updating assessments for FCW and AEB technologies (i.e., 
CIB and DBS) in NCAP's crash avoidance program. As discussed in NHTSA's 
March 2022 RFC notice, these technologies, designed to address forward 
collisions (rear-end crashes), have the potential to help prevent or 
mitigate rear-end pre-crash scenarios representing approximately 1.7 
million crashes annually, or 29 percent of all crashes that currently 
occur on U.S. roadways.\31\ These crashes result in 1,275 fatalities, 
on average, and 883,386 MAIS 1-5 injuries annually, representing 3.8 
percent of all fatalities and 32 percent of all injuries, 
respectively.\32\ FCW and AEB technologies have proven effective in 
reducing crashes, fatalities, and injuries. For instance, as discussed 
in the March 2022 RFC notice, the University of Michigan Transportation 
Research Institute (UMTRI) found that for 3.8 million model year 2013-
2017 GM vehicles, camera-based FCW systems produced an estimated 21 
percent reduction in rear-end striking crashes, while the AEB systems 
studied (which included a combination of camera-only, radar-only, and 
fused camera-radar systems) produced an estimated 46 percent reduction 
in the same crash type.\33\ These findings align with a 2017 Insurance 
Institute for Highway Safety (IIHS) study,\34\ which concluded that 
vehicles equipped with FCW and AEB showed a 50 percent reduction for 
the same crash type.\35\
---------------------------------------------------------------------------

    \31\ Wang, J.-S. (2019, March), Target crash population for 
crash avoidance technologies in passenger vehicles (Report No. DOT 
HS 812 653). Washington, DC: National Highway Traffic Safety 
Administration.
    \32\ The Abbreviated Injury Scale (AIS) is a classification 
system for assessing impact injury severity. AIS ranks individual 
injuries by body region on a scale of 1 to 6 where 1=minor, 
2=moderate, 3=serious, 4=severe, 5=critical, and 6=maximum 
(untreatable). MAIS represents the maximum injury severity, or AIS 
level, recorded for an occupant (i.e., the highest single AIS for a 
person with one or more injuries).
    \33\ Leslie, A.J., Kiefer, R.J., Meitzner, M.R., & Flannagan, 
C.A. (2019), Analysis of the field effectiveness of General Motors 
production active safety and advanced headlighting systems, The 
University of Michigan Transportation Research Institute and General 
Motors LLC. UMTRI-2019-6.
    \34\ Cicchino, J.B. (2017, February), Effectiveness of forward 
collision warning and autonomous emergency braking systems in 
reducing front-to-rear crash rates, Accident Analysis and 
Prevention, 2017 Feb;99(Pt A):142-152. https://doi.org/10.1016/j.aap.2016.11.009.
    \35\ Low-speed AEB showed a 43% reduction.
---------------------------------------------------------------------------

    Until these technologies are standard equipment on all passenger 
vehicles, it is important for NCAP to continue to recommend FCW and AEB 
technologies to consumers and to inform them which vehicles have FCW 
and AEB technologies meeting NHTSA's performance criteria. Further, 
given recent increases in the penetration of FCW and AEB technologies 
in the vehicle fleet and improvements to sensors, now is an opportune 
time to increase the stringency of the current NCAP performance 
requirements for these technologies.

A. Forward Collision Warning (FCW)

    FCW systems use forward-looking sensors (e.g., radar, lidar, camera 
systems, or a combination thereof) that detect objects (e.g., vehicles, 
pedestrians) in front of vehicles and issue an alert to the driver. An 
FCW system uses the sensors' input to determine the speed of the object 
in front of it and the distance between the vehicle and the object. If 
the sensing system determines that the closing distance and velocity 
\36\ between the driver's vehicle and the object in front of it is such 
that a collision may be imminent, the warning system is designed to 
induce an immediate crash avoidance response by the vehicle operator. 
Warning systems in use today provide drivers with a visual display, 
such as an illuminated telltale on or near the instrument panel, an 
auditory signal (e.g., buzzer or chime), and/or a haptic signal that 
provides tactile feedback (e.g., rapid vibrations of the seat pan or 
steering wheel). These signals warn the driver of an impending 
collision so the driver may then manually intervene (e.g., apply the 
vehicle's brakes or make an evasive steering maneuver) to avoid or 
mitigate a crash. FCW systems alone do not brake the vehicle.
---------------------------------------------------------------------------

    \36\ Closing velocity is the rate at which two objects are 
getting closer to each other.
---------------------------------------------------------------------------

    NHTSA added FCW systems to its NCAP ADAS evaluations in 2008 (with 
performance evaluations beginning with model year 2011 vehicles) 
because these systems met the Agency's four prerequisites for inclusion 
at the time.\37\ In its March 2022 RFC notice, the Agency proposed to 
continue to include FCW assessments in NCAP, as it found FCW systems to 
be effective, well-accepted by consumers, and widely available in the 
current vehicle fleet. For example, in its 2017 study, IIHS \38\ found 
that FCW systems reduced rear-end crashes by 27 percent. Further, in a 
2019 survey of more than 57,000 Consumer Reports subscribers, 69 
percent of vehicle owners reported they were satisfied with their 
vehicle's FCW technology.\39\ Currently, manufacturer-submitted data 
collected by NHTSA indicates 91 percent of model year 2023 vehicles are 
equipped with FCW systems as standard equipment.
---------------------------------------------------------------------------

    \37\ 73 FR 40033 (July 11, 2008).
    \38\ Cicchino, J.B. (2017, February), Effectiveness of forward 
collision warning and autonomous emergency braking systems in 
reducing front-to-rear crash rates, Accident Analysis and 
Prevention, 2017 Feb;99(Pt A):142-152. https://doi.org/10.1016/j.aap.2016.11.009.
    \39\ Consumer Reports (2019, November), Consumer Perception of 
ADAS, https://data.consumerreports.org/reports/consumer-perceptions-of-adas/.
---------------------------------------------------------------------------

NCAP's Current Forward Collision Warning Test Procedure
    The Agency included FCW as a recommended technology in NCAP and 
conducted performance evaluations beginning with model year 2011 
vehicles. The FCW test procedure adopted at that time is still in use 
in the Agency's testing today.\40\
---------------------------------------------------------------------------

    \40\ 73 FR 40016 (July 11, 2008).
---------------------------------------------------------------------------

    Currently, NCAP's FCW test procedure \41\ consists of three 
scenarios that simulate the most frequent types of rear-end crashes. 
These include lead vehicle stopped (LVS), lead vehicle decelerating 
(LVD), and lead vehicle moving (LVM) scenarios. In each scenario, the 
vehicle being evaluated is called the subject vehicle (SV). The SV is 
driven by a professional driver who provides the necessary 
acceleration, braking, and steering inputs during the test. A 
production mid-size passenger car, designated as the principal other 
vehicle (POV) during testing, is positioned directly in front of the SV 
and is also driven by a professional driver. Time-to-collision (TTC) 
criteria are prescribed for each FCW scenario. The TTC for each 
scenario is calculated by considering the speed of the SV relative to 
the POV at the time of the FCW. If the FCW system fails to issue a 
warning within the required time during testing, the SV's professional 
test

[[Page 95928]]

driver brakes, or steers away, to avoid a collision with the POV. A 
short description of each test scenario and the requirements for a 
passing result based on the prescribed TTC is provided below:
---------------------------------------------------------------------------

    \41\ National Highway Traffic Safety Administration. (2013, 
February). Forward collision warning system confirmation test. 
https://www.regulations.gov. Docket No. NHTSA-2006-26555-0134.
---------------------------------------------------------------------------

     LVS--The SV encounters a stopped POV directly in front of 
it on a straight road. The SV is moving at 72.4 kph (45 mph), and the 
POV is stationary. To pass this test, the SV must issue an FCW when the 
TTC is at least 2.1 s. See Figure 1 (below) for a scenario diagram.
[GRAPHIC] [TIFF OMITTED] TN03DE24.000

     LVD--The SV encounters a POV slowing with constant 
deceleration directly in front of it on a straight road. The SV and POV 
are both driven at 72.4 kph (45 mph) with an initial headway of 30.0 m 
(98.4 ft.). The POV then decelerates, braking at a constant 
deceleration of 0.3g in front of the SV. To pass this test, the SV must 
issue an FCW when the TTC is at least 2.4 s. See Figure 2 (below) for a 
scenario diagram.
[GRAPHIC] [TIFF OMITTED] TN03DE24.001

     LVM--The SV encounters a slower-moving POV directly in 
front of it on a straight road. The SV and POV are driven at constant 
speeds of 72.4 kph (45 mph) and 32.2 kph (20 mph), respectively. To 
pass this test, the SV must issue an FCW when the TTC is at least 2.0 
s. See Figure 3 (below) for a scenario diagram.
[GRAPHIC] [TIFF OMITTED] TN03DE24.002

    Each of these three scenarios is conducted up to seven times. To 
pass the NCAP FCW system performance tests, the SV must satisfy the 
respective TTC-based performance criteria for at least five out of 
seven trials \42\ for each of the three test scenarios.
---------------------------------------------------------------------------

    \42\ As noted in the Agency's 2015 AEB final decision notice (80 
FR 68618 (Nov. 5, 2015)), a pass rate of five out of seven tests per 
scenario was adopted for NCAP's current FCW test protocol to provide 
the Agency with a way to encourage system robustness without 
precluding the proliferation of emerging technologies offering the 
potential for significant safety benefits.
---------------------------------------------------------------------------

B. Automatic Emergency Braking (AEB)

    One limitation of FCW systems is that, although designed to warn 
the driver of an impending rear-end crash, they do not actively and 
automatically assist drivers with avoiding rear-end crashes or 
mitigating their severity. To address this, CIB and DBS (known 
collectively as AEB) both provide significant automatic braking of the 
vehicle.\43\ DBS systems provide supplemental braking when sensors 
determine that driver-applied braking is insufficient to avoid an 
imminent crash. CIB systems provide automatic braking when forward-
looking sensors indicate that a crash is imminent, and the driver has 
not braked.
---------------------------------------------------------------------------

    \43\ Some FCW systems use haptic brake pulses to alert the 
driver of a crash-imminent driving situation, but they are not 
intended to effectively slow the vehicle.
---------------------------------------------------------------------------

    Research has shown that active safety systems such as AEB provide 
greater safety benefits than the corresponding warning systems alone, 
such as FCW. In its 2019 study, UMTRI \44\ found that

[[Page 95929]]

AEB systems produced an estimated 46 percent reduction in applicable 
rear-end crashes when combined with a forward collision warning, which 
alone showed only a 21 percent reduction.\45\ Like FCW systems, AEB 
systems are also well-accepted by consumers and widely available in the 
current vehicle fleet. In Consumer Reports' 2019 subscriber survey, 81 
percent of owners of vehicles equipped with AEB reported they were 
satisfied with AEB technology.\46\ Currently, manufacturer-submitted 
data collected by NHTSA indicates approximately 91 percent of model 
year 2023 vehicles are equipped with AEB systems as standard equipment. 
For these reasons, in 2015, NHTSA added CIB and DBS technologies to its 
ADAS assessments starting with model year 2018 vehicles, and why the 
Agency also proposed to continue to include AEB assessments in NCAP in 
its March 2022 RFC notice.\47\
---------------------------------------------------------------------------

    \44\ Leslie, A.J., Kiefer, R.J., Meitzner, M.R., & Flannagan, 
C.A. (2019, September), Analysis of the field effectiveness of 
General Motors production active safety and advanced headlighting 
systems, The University of Michigan Transportation Research 
Institute and General Motors LLC, UMTRI-2019-6.
    \45\ The AEB systems studied by UMTRI consisted of camera-only, 
radar-only, and fused camera-radar AEB systems, the latter two 
systems of which also included adaptive cruise control 
functionality.
    \46\ Consumer Reports, (2019, November), Consumer Perceptions of 
ADAS, https://data.consumerreports.org/reports/consumer-perceptions-of-adas/.
    \47\ Docket No. NHTSA-2021-0002. 87 FR 13452. March 9, 2022.
---------------------------------------------------------------------------

1. Dynamic Brake Support (DBS)
    Like FCW (and CIB) systems, DBS systems employ forward-looking 
sensors to detect vehicles in the path directly ahead while 
simultaneously monitoring the operational state of the driver's vehicle 
(e.g., speed, the relative speed of and distance to the lead vehicle, 
driver inputs of steering and braking). In response to an FCW or an 
imminent crash, a driver may initiate braking to avoid a rear-end 
crash. However, research suggests that a driver's brake application may 
not take full advantage of the vehicle's foundation braking system in 
cases where the driver is inattentive, receives an FCW, and re-engages 
in the driving task prior to automatic braking (i.e., CIB) taking 
place. In situations where the driver's braking is insufficient to 
prevent a collision, DBS can automatically supplement the driver's 
braking action to prevent or mitigate the crash.\48\ The NCAP DBS 
performance evaluations serve to ensure that the vehicle's supplemental 
braking is sufficient to augment the driver's manual brake application 
and avoid a collision with the lead vehicle in the tested driving 
situations. DBS testing also endeavors to ensure that a vehicle's 
automatic brake application (i.e., CIB) is not suppressed in the event 
of a driver's manual brake application.
---------------------------------------------------------------------------

    \48\ DBS systems differ from traditional brake assist systems 
used with the vehicle's foundation brakes. Whereas both systems rely 
on brake pedal application rate to determine whether supplemental 
braking is required, DBS has a lower activation threshold since it 
also uses information from forward-looking sensors to verify that 
more braking is needed.
---------------------------------------------------------------------------

NCAP's Current Dynamic Brake Support Test Procedure
    NCAP's current DBS test procedure \49\ consists of the same three 
rear-end pre-crash scenarios specified in the FCW system performance 
test procedure: LVS, LVD, and LVM. However, most of the test speed 
combinations specified in the DBS test procedure differ. The single 
exception is that the FCW and DBS test procedures both use an LVM test 
performed with SV and POV speeds of 72.4 and 32.2 kph (45 and 20 mph), 
respectively. The DBS performance assessment also includes a Steel 
Trench Plate (STP) false positive suppression test conducted at two 
test speeds. The false positive suppression test series evaluates the 
ability of a DBS system to differentiate a steel trench plate, often 
found on roadways, from an object presenting a genuine safety risk to 
the SV. Although STPs are large and metallic, they are designed to be 
driven over without risk of injury to drivers or vehicles. This fourth 
test scenario is used to evaluate the propensity of a vehicle's DBS 
system to activate inappropriately in this non-critical driving 
scenario that would not present a safety risk to the vehicle's 
occupants.
---------------------------------------------------------------------------

    \49\ National Highway Traffic Safety Administration (2015, 
October), Dynamic brake support performance evaluation confirmation 
test for the New Car Assessment Program, http://www.regulations.gov, 
Docket No. NHTSA-2015-0006-0026.
---------------------------------------------------------------------------

    Like NCAP's FCW tests, the vehicle subjected to the DBS test 
scenarios is termed the SV. However, unlike NCAP's FCW tests, the DBS 
test procedure uses a surrogate vehicle (i.e., a realistic looking 
artificial vehicle) as the POV instead of an actual vehicle to limit 
the potential for damage to the SV and/or the test equipment in the 
event of a collision. Additionally, instead of driver- (human-) based 
inputs, like those required in NCAP's FCW tests, a programmable 
(robotic) brake controller is used to provide all SV brake pedal 
applications made during the DBS system performance evaluations.
    The Strikeable Surrogate Vehicle (SSV) is the surrogate vehicle 
presently used as the POV by NCAP for the Agency's DBS testing. The 
SSV, developed by NHTSA for the purpose of track testing, appears as a 
``real'' vehicle to the camera, radar, and lidar sensors used by 
existing AEB systems. The SSV system is comprised of (a) a shell,\50\ 
which is a visually and dimensionally accurate representation of a 
compact passenger car; (b) a slider and load frame assembly to which 
the shell is attached, (c) a two-rail track on which the slider 
operates, (d) a road-based lateral restraint track, and (e) a tow 
vehicle, which pulls the SSV and its peripherals down the test track 
during the test where the POV (i.e., SSV) must be in motion.
---------------------------------------------------------------------------

    \50\ The shell is constructed from lightweight composite 
materials with favorable strength-to-weight characteristics, 
including carbon fiber, Kevlar[supreg], phenolic, and Nomex 
honeycomb. It is also wrapped with a commercially available vinyl 
material to simulate paint on the body panels, rear bumper, and a 
tinted glass rear window. A foam bumper having a neoprene cover is 
attached to the rear of the SSV to reduce the peak forces realized 
immediately after an impact from a test vehicle occurs.
---------------------------------------------------------------------------

    For the three test scenarios where braking is expected, the SV must 
provide enough supplemental braking to completely avoid contact with 
the SSV (i.e., POV) to pass a trial run. In the case of the DBS false 
positive test scenario, the performance criterion is minimal to no 
activation for both test speeds.51 52 A short description of 
each DBS system performance test scenario, and the requirements for a 
passing result, is provided below:
---------------------------------------------------------------------------

    \51\ Minimal activation is defined as a peak SV deceleration 
attributable to DBS intervention that is less than or equal to 1.5 
times the average of the deceleration recorded for the vehicle's 
foundation brake system alone during its approach to the STP. The 
1.5 multiplier serves to provide some system flexibility, meaning a 
mild DBS intervention is acceptable, but one where the vehicle 
thinks it must respond to the STP as if it was a real vehicle is 
not.
    \52\ Note that the March 2022 notice specified a multiplier of 
1.25. This specification was in error.
---------------------------------------------------------------------------

     Lead Vehicle Stopped (LVS)--The SV encounters a stopped 
POV directly in front of it on a straight road. The SV is moving at 
40.2 kph (25 mph) and the POV is stationary. The SV throttle is 
released within 500 ms after the SV issues an FCW, and the SV brake 
pedal is manually applied at a TTC of 1.1 s (i.e., at a nominal headway 
of 12.2 m (40 ft.)). To pass this test, the SV must not contact the 
POV. See Figure 1 for a scenario diagram.
     Lead Vehicle Decelerating (LVD)--The SV encounters a POV 
slowing with constant deceleration directly in front of it on a 
straight road. The SV and POV are both driven at 56.3 kph (35 mph) with 
an initial headway of 13.8 m (45.3 ft.). The POV brakes are then 
applied to achieve a constant deceleration of 0.3g in front of the SV. 
The SV throttle is released within 500 ms after the SV issues an FCW, 
and the SV brake pedal

[[Page 95930]]

is manually applied at a TTC of 1.4 s (i.e., at a nominal headway of 
9.6 m (31.5 ft.)). To pass this test, the SV must not contact the POV. 
See Figure 2 for a scenario diagram.
     Lead Vehicle Moving (LVM)--The SV encounters a slower-
moving POV directly in front of it on a straight road. In the first 
test, the SV and POV are driven on a straight road at a constant speed 
of 40.2 kph (25 mph) and 16.1 kph (10 mph), respectively. In the second 
test, the SV and POV are driven at a constant speed of 72.4 kph (45 
mph) and 32.2 kph (20 mph), respectively. In both tests, the SV 
throttle is released within 500 ms after the SV issues an FCW, and the 
SV brake pedal is manually applied at a TTC of 1 s (i.e., at a nominal 
headway of 6.7 m (22 ft.) in the first test, and 11.3 m (37 ft.) in the 
second test). To pass these tests, the SV must not contact the POV. See 
Figure 3 for a scenario diagram.
     Steel Trench Plate (STP) false positive suppression test--
The SV is driven over a 2.4 m x 3.7 m x 25.4 mm (8 ft. x 12 ft. x 1 
in.) steel trench plate at 40.2 kph (25 mph) and 72.4 kph (45 mph). If 
an FCW is issued, the SV throttle is released within 500 ms of the 
alert. If no FCW is issued by a TTC of 2.1 s, the SV throttle is 
released within 500 ms of a TTC of 2.1 s. In both instances, the SV 
brakes are applied at a TTC of 1.1 s (i.e., at a nominal distance of 
12.3 m (40 ft.) from the edge of the STP at 40.2 kph (25 mph), or 22.3 
m (73 ft.) at 72.4 kph (45 mph)). To pass this test, the performance 
criterion is minimal to no activation, as defined previously. See 
Figure 4 (below) for a scenario diagram.
[GRAPHIC] [TIFF OMITTED] TN03DE24.003

    Currently, to pass NCAP's DBS system performance criteria, the SV 
must pass at least five out of seven trials for each of the six test 
conditions.
2. Crash Imminent Braking (CIB)
    If a driver does not manually apply the vehicle's brakes when a 
rear-end crash is imminent, CIB systems, using the same forward-looking 
sensors as DBS systems, apply the vehicle's brakes automatically to 
slow or stop the vehicle. Unlike DBS systems, which provide additional 
braking to supplement the driver's brake input, CIB systems activate 
when the driver has not applied the brake pedal.
NCAP's Current Crash Imminent Braking (CIB) Test Procedure
    The Agency's current CIB test procedure \53\ is comprised of the 
same four test scenarios (LVS, LVD, LVM, and the STP false positive 
suppression test) and test speeds specified in the DBS test procedure. 
However, the performance criteria vary slightly. Whereas collision 
avoidance is the performance requirement stipulated for all DBS test 
scenarios except the false positive scenario, only the LVM 40.2 kph/
16.1 kph (25 mph/10 mph) CIB test condition requires that the SV not 
contact the POV. The LVS, LVD, and the LVM 72.4 kph/32.2 kph (45 mph/20 
mph) test conditions permit SV-to-POV contact but require minimum SV 
speed reductions prior to the contact being made. For the CIB false 
positive tests, the performance criterion is little-to-no activation, 
like the comparable DBS tests. Also, like NCAP's DBS tests, the SSV is 
the POV presently used in the program's CIB testing. A short 
description of each test scenario and the requirements for a passing 
result are provided below:
---------------------------------------------------------------------------

    \53\ National Highway Traffic Safety Administration. (2015, 
October). Crash imminent brake system performance evaluation for the 
New Car Assessment Program. http://www.regulations.gov. Docket No. 
NHTSA-2015-0006-0025.
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     LVS--The SV encounters a stopped POV directly in front of 
it on a straight road. The SV is moving at 40.2 kph (25 mph) and the 
POV (i.e., the SSV) is stationary. The SV throttle is released within 
500 ms after the SV issues an FCW. To pass this test, the SV speed 
reduction attributable to CIB intervention must be >= 15.8 kph (9.8 
mph). See Figure 1 for a scenario diagram.
     LVD--The SV encounters a POV slowing with constant 
deceleration directly in front of it on a straight road. The SV and POV 
are both driven at 56.3 kph (35 mph) with an initial headway of 13.8 m 
(45.3 ft.). The POV then decelerates, braking at a constant 
deceleration of 0.3g in front of the SV, after which the SV throttle is 
released within 500 ms after the SV issues an FCW. To pass this test, 
the SV speed reduction attributable to CIB intervention must be >= 16.9 
kph (10.5 mph). See Figure 2 for a scenario diagram.
     LVM--The SV encounters a slower-moving POV directly in 
front of it on a straight road. In the first test, the SV and POV are 
driven on a straight road at a constant speed of 40.2 kph (25 mph) and 
16.1 kph (10 mph), respectively. In the second test, the SV and POV are 
driven at a constant speed of 72.4 kph (45 mph) and 32.2 kph (20 mph), 
respectively. In both tests, the SV throttle is released within 500 ms 
after the SV issues an FCW. To pass the first test, the SV must not 
contact the POV. To pass the second test, the SV speed reduction 
attributable to CIB intervention must be >= 15.8 kph (9.8 mph). See 
Figure 3 for a scenario diagram.
     STP test (to assess false positive suppression)--The SV is 
driven towards a steel trench plate at 40.2 kph (25 mph) in one test 
and 72.4 kph (45 mph) in the other test. If an FCW is issued, the SV 
throttle is released within 500 ms of the alert. If no FCW is issued, 
the throttle is not released until the test's validity period (the time 
when all test specifications and tolerances must be satisfied) has 
passed. To pass these tests, the SV must not achieve a peak 
deceleration equal to or greater than 0.5g at any time during its 
approach to the steel trench plate. See Figure 4 for a scenario 
diagram.
    To pass NCAP's CIB system performance criteria, the SV must pass at 
least five out of seven trials for each of the six test conditions.

[[Page 95931]]

C. Linking Current FCW and AEB Test Scenarios With Real-World Crashes
    NCAP's FCW and AEB test scenarios are directly related to real-
world crash data. From its analysis of 2011 to 2015 Fatality Analysis 
Reporting System (FARS) and National Automotive Sampling System General 
Estimate System (GES) data, the Agency found that crashes analogous to 
the LVS test scenario, where a struck vehicle was stopped at the time 
of impact, occurred in 65 percent of the rear-end crashes 
studied.54 55 The LVD scenario, in which the struck vehicle 
was decelerating at the time of impact, occurred in 22 percent of the 
rear-end crashes, and the LVM scenario, in which the struck vehicle was 
moving at a constant, but slower, speed compared to the striking 
vehicle at impact, occurred in 10 percent of the rear-end crashes. 
Collectively, these test scenarios represented 97 percent of rear-end 
crashes.
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    \54\ Wang, J.-S. (2019, March), Target crash population for 
crash avoidance technologies in passenger vehicles (Report No. DOT 
HS 812 653), Washington, DC: National Highway Traffic Safety 
Administration.
    \55\ NHTSA notes that the target crash populations reported for 
the LVS, LVD, and LVM scenarios encompass all related real-world 
rear-end crashes (where the light vehicle is making a critical 
action) that could potentially be addressed by a DBS system. As 
such, the target crash populations for each crash scenario reflect 
crashes exhibiting variations in vehicle overlap, roadway curvature, 
environmental conditions, etc.; target crash populations were not 
reduced to align exactly with those represented by NCAP's LVS, LVD, 
and LVM test scenarios.
---------------------------------------------------------------------------

    With respect to test speed, in its independent review of the 2011-
2015 FARS and GES data sets, the John A. Volpe National Transportation 
Systems Center (Volpe) concluded that, when posted speed limit was 
known, 2 percent of fatal rear-end crashes and 6 percent of all rear-
end crashes occurred on roadways with posted speed limits of 40.2 kph 
(25 mph) or less.56 57 58 Eleven percent of fatal rear-end 
crashes and 33 percent of all rear-end crashes where posted speed limit 
was known occurred on roads with posted speeds of 56.3 kph (35 mph) or 
less. For posted speeds of 72.4 kph (45 mph) or less, Volpe found the 
comparable statistics to be 29 percent and 70 percent, respectively.
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    \56\ Swanson, E., Foderaro, F., Yanagisawa, M., Najm, W.G., & 
Azeredo, P. (2019, August), Statistics of light-vehicle pre-crash 
scenarios based on 2011-2015 national crash data (Report No. DOT HS 
812 745), Washington, DC: National Highway Traffic Safety 
Administration.
    \57\ NHTSA notes that throughout this notice, all crash 
statistics cited from Report No. DOT HS 812 745 encompass those 
where the light vehicle made the critical action (e.g., losing 
control, departing road, changing lanes, striking, maneuvering, 
etc.).
    \58\ For rear-end crashes, posted speed limit was unknown or not 
reported for 2 percent of fatal crashes and 11 percent of injurious 
crashes.
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    Roadway alignment and grade for the current FCW and AEB test 
scenarios are also comparable to those found where real-world rear-end 
crashes occur. NHTSA's LVS, LVD, and LVM procedures are to be performed 
on straight, level roads. In its review of 2011-2015 FARS and GES data 
sets, for rear-end crashes where roadway alignment was known, Volpe 
found that 95 percent of both fatal and injurious crashes occurred on a 
straight roadway.\59\ For rear-end crashes where roadway grade was 
known, 77 percent of fatal crashes and 84 percent of crashes with 
injuries occurred on level roads.\60\
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    \59\ For rear-end crashes, roadway alignment was unknown or not 
reported for 1 percent of fatal crashes and 3 percent of injurious 
crashes.
    \60\ For rear-end crashes, roadway grade was unknown or not 
reported for 4 percent of fatal crashes and 18 percent of injurious 
crashes.
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1. AEB Installation Rates, Effectiveness, and Research Tests
a. AEB Installation Rates
    When NHTSA's CIB test scenarios were developed, relatively few 
vehicles were equipped with this technology; those that were equipped 
had systems with limited capabilities. Since then, fitment rates for 
CIB systems have increased significantly due in part to a voluntary 
industry commitment made in March 2016.\61\ Per this commitment, 20 
vehicle manufacturers, representing more than 99 percent of light motor 
vehicle sales in the U.S., voluntarily committed to make FCW and CIB 
standard on virtually all light-duty vehicles with a gross vehicle 
weight rating (GVWR) of 3,855.5 kg (8,500 pounds) or less beginning no 
later than September 1, 2022, and all trucks with a GVWR between 
3,856.0 and 4,535.9 kg (8,501 and 10,000 pounds) beginning no later 
than September 1, 2025.\62\ Conforming vehicles were required to be 
equipped with (1) an AEB system that earned at least an ``advanced'' 
rating from IIHS in its then-current front crash prevention track LVS 
tests and (2) an FCW system that met the performance requirements 
specified in two of NCAP's current three FCW test scenarios, LVD and 
LVM.\63\ By 2019, participating manufacturers had equipped 75 percent 
of their new vehicle fleet with AEB,\64\ and for model year 2023 
vehicles, approximately 91 percent of the fleet was equipped with FCW 
and AEB systems as standard equipment.
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    \61\ The Agency also asserts that its recommendation of AEB 
systems (i.e., CIB and DBS) that meet NCAP performance criteria on 
its website since the 2018 model year has further encouraged 
adoption of these technologies.
    \62\ Insurance Institute for Highway Safety (2016, March 17), 
U.S. DOT and IIHS announce historic commitment of 20 automakers to 
make automatic emergency braking standard on new vehicles, https://www.iihs.org/news/detail/u-s-dot-and-iihs-announce-historic-commitment-of-20-automakers-to-make-automatic-emergency-braking-standard-on-new-vehicles.
    \63\ To achieve an advanced rating in IIHS' front crash 
prevention track tests, a vehicle's AEB system must show a speed 
reduction of at least 16.1 kph (10 mph) in either IIHS's 19.3 or 
40.2 kph (12 or 25 mph) tests, or a speed reduction of 8.0 kph (5 
mph) in both tests. https://www.iihs.org/news/detail/u-s-dot-and-iihs-announce-historic-commitment-of-20-automakers-to-make-automatic-emergency-braking-standard-on-new-vehicles.
    \64\ National Highway Traffic Safety Administration (2019, 
December 17), NHTSA announces update to historic AEB commitment by 
20 automakers, https://www.nhtsa.gov/press-releases/nhtsa-announces-update-historic-aeb-commitment-20-automakers.
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    As fitment increased, the sensor technology for CIB systems also 
advanced significantly. In 2017, many systems were not designed to meet 
the voluntary commitment thresholds, whereas by 2021, most vehicles 
with FCW and CIB systems could pass all relevant NCAP test scenarios, 
most of which are more stringent than those included in the voluntary 
agreement.\65\ In its RFC, NHTSA noted that the original equipment 
manufacturer (OEM)-reported pass rate for NCAP's FCW and CIB tests for 
model year 2021 vehicles \66\ equipped with these technologies, and for 
which manufacturers submitted data, was 89 percent and 70 percent, 
respectively.\67\ Furthermore, NHTSA mentioned that only 63 percent of 
model year 2017 vehicles avoided contacting the POV for at least five 
out of seven of the required runs in the LVS CIB scenario during the 
Agency's testing, whereas 100 percent of model year 2021 vehicles were 
able to repeatedly avoid contact when tested.\68\ It should be noted 
that a speed reduction of 15.8 kph (9.8 mph) for at least five out of 
seven trial runs is currently required to pass NCAP's CIB LVS test, not 
complete crash avoidance. For the model year 2023 vehicle fleet, the 
OEM-reported pass rate for the Agency's FCW test was 98 percent of 
equipped vehicles, and 86 percent for

[[Page 95932]]

the CIB test. In the Agency's model year 2023 CIB testing, all vehicles 
avoided contacting the POV test device for at least five out of seven 
runs, and thus received credit for passing performance. For the FCW 
assessments, only one vehicle model failed to provide a passing 
performance for the LVS and LVD scenarios.
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    \65\ NCAP's CIB test protocol requires a speed reduction of at 
least 15.8 kph (9.8 mph) in the program's 40 kph (24.9 mph) LVS 
test. However, the voluntary commitment allows a vehicle to comply 
with the memorandum for a speed reduction of 8.0 kph (5 mph) in 
IIHS's 19.3 and 40.2 kph (12 and 25 mph) LVS tests.
    \66\ In this instance, ``vehicles'' refers to the total number 
of vehicles in the 2021 fleet, and not the total number of vehicle 
models for that year.
    \67\ These values assume a 50 percent take rate for vehicles 
having optional equipment.
    \68\ No contact was assumed if the test vehicle did not contact 
the POV in five or more of the seven required trial runs.
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b. Model Year 2019 and 2020 Research Testing
    As NHTSA noted in its March 2022 RFC, research testing conducted 
for a sample of model year 2019 and 2020 vehicles from various 
manufacturers also confirmed advancement of CIB system capabilities in 
recent years. The goal of this testing was to characterize the 
performance of then-current CIB systems and evaluate the technology's 
future potential for the new model years' vehicle fleet. For this 
purpose, the Agency chose to focus testing on NCAP's LVS and LVD test 
scenarios, as its review of the 2011-2015 FARS and GES rear-end crash 
data sets showed that LVS and LVD rear-end scenarios resulted in the 
highest number of crashes and MAIS 1-5 injuries.\69\ NHTSA conducted 
testing for each scenario in accordance with NCAP's current CIB test 
procedure. These tests were then repeated using an ABD GVT as the 
surrogate vehicle in lieu of the SSV to verify that little to no change 
in performance would result.\70\ The Agency also performed additional 
tests for each scenario using the GVT to assess how specific procedural 
changes (i.e., increases in test speed and POV deceleration magnitude) 
affected CIB system performance.\71\
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    \69\ Per Wang, J.-S. (2019, March), Target crash population for 
crash avoidance technologies in passenger vehicles (Report No. DOT 
HS 812 653), Washington, DC: National Highway Traffic Safety 
Administration, there were 1,099,868 LVS, 374,624 LVD, and 174,217 
LVM crashes annually. Furthermore, there were 561,842 MAIS 1-5 
injuries resulting from the LVS crash scenario, 196,731 for LVD, and 
97,402 for LVM. The LVS scenario also had the second highest number 
of fatalities.
    \70\ The Agency desired to use the GVT in lieu of the SSV for 
its higher speed testing because, given its material properties, the 
GVT significantly reduced the potential for damage to the testing 
equipment and test vehicles.
    \71\ Test reports related to NHTSA's CIB characterization 
testing can be found in the docket for the March 2022 RFC notice.
---------------------------------------------------------------------------

    For the additional LVS tests, the Agency incrementally increased 
the vehicle speed from 40.2 to 72.4 kph (25 to 45 mph) in 8.0 kph (5 
mph) increments to identify when or if the vehicle reached its 
operational limits and/or did not react to the POV ahead. When the 
vehicle's intervention was insufficient (i.e., the SV's maximum (peak) 
deceleration was less than 0.5g), the Agency repeated the test scenario 
at a test speed that was 4.0 kph (2.5 mph) lower. This reduced speed 
was used to define the system's upper capabilities for the LVS 
scenario.
    For the additional LVD tests, the Agency evaluated how changes made 
to either the SV and POV speed (72.4 kph versus 56.3 kph (45 mph versus 
35 mph)) or POV deceleration magnitude (0.5g versus 0.3g) affected CIB 
performance. No changes were made to the SV-to-POV headway; it was 
retained at 13.8 m (45.3 ft.).
    The Agency chose to increase the test speeds for the scenarios 
included in its CIB characterization study because, in its independent 
analysis of the 2011-2015 FARS data set, Volpe found that, when the 
posted speed limit was known, approximately 29 percent of fatalities 
and 70 percent of injuries in rear-end crashes occurred when the posted 
speed on roadways was 72.4 kph (45 mph) or less.\72\ The additional 
change to increase the POV deceleration in the LVD scenario was 
intended to create a more stringent test to address situations where 
the driver of a lead vehicle brakes aggressively, causing the driver of 
the following vehicle to have even less time to avoid or mitigate the 
crash than had the lead vehicle braking been at the 0.3g level 
presently specified in the Agency's test procedure. Based on previous 
Agency research, when drivers need to apply the brakes in a non-
emergency situation, they do so by decelerating up to approximately 
0.306g, while drivers encountering an unexpected obstacle apply the 
brakes at 0.48g.\73\ Further, NHTSA noted that a deceleration of 0.5g 
falls within the range of deceleration magnitudes prescribed by Euro 
NCAP in its AEB Car-to-Car systems test protocol, Version 3.0.3, dated 
April 2021 for the Car-to-Car rear braking CCRb scenario. In its CCRb 
test, Euro NCAP specifies POV deceleration magnitudes of 2 m/s\2\ and 6 
m/s\2\ (approximately 0.2 to 0.6 g) for an SV-to-POV headway of 12 m 
(39.4 ft.) and SV test speed of 50 kph (31.1 mph).
---------------------------------------------------------------------------

    \72\ Swanson, E., Foderaro, F., Yanagisawa, M., Najm, W.G., & 
Azeredo, P. (2019, August), Statistics of light-vehicle pre-crash 
scenarios based on 2011-2015 national crash data (Report No. DOT HS 
812 745), Washington, DC: National Highway Traffic Safety 
Administration.
    \73\ Gregory M. Fitch, Myra Blanco, Justin F. Morgan, Jeanne C. 
Rice, Amy Wharton, Walter W. Wierwille, and Richard J. Hanowski 
(2010, April) Human Performance Evaluation of Light Vehicle Brake 
Assist Systems: Final Report (Report No. DOT HS 811 251) Washington, 
DC: National Highway Traffic Safety Administration, p. 13 and p. 
101.
---------------------------------------------------------------------------

    The Agency's characterization testing showed that many vehicles 
were able to repeatedly provide complete crash avoidance at higher test 
speeds and generally more aggressive conditions than those specified in 
NCAP's current CIB test procedure. For the 56.3 kph (35.0 mph) LVS 
tests conducted with a POV deceleration of 0.3g, seven out of the 
eleven vehicles avoided contact with the lead vehicle in every test 
trial. One of the remaining vehicles avoided contact in six out of 
seven test trials and the other three vehicles demonstrated an average 
speed reduction that exceeded 30.6 kph (19 mph). For the 72.4 kph (45.0 
mph) LVS tests conducted with a POV deceleration of 0.3g, four out of 
the eleven vehicles avoided contact in every test trial and two other 
vehicles avoided contact in all but one test trial. Three of the 
remaining vehicles avoided contact in one or two test trials, while the 
two other vehicles could not avoid contact but both demonstrated an 
average 21 kph (13 mph) speed reduction. For the 56.3 kph (35.0 mph) 
LVD tests conducted at 0.5g rather than 0.3g, as specified in NCAP's 
current CIB test procedure, eight vehicles demonstrated the ability to 
avoid contact with the lead vehicle in at least one trial and three 
vehicles avoided contact in all trials, despite having less time to 
avoid the crash.\74\ Similarly, when the speed of the SV and lead 
vehicle was increased to 72.4 kph (45 mph), nine vehicles demonstrated 
the ability to avoid contact with the lead vehicle in at least one test 
while four vehicles avoided contact in all tests. One vehicle avoided 
contact in all lead vehicle decelerating trials, including both 
increased speeds and increased lead vehicle deceleration.
---------------------------------------------------------------------------

    \74\ Two vehicles avoided contact with the POV in four out of 
five trials.
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    Given these findings, the Agency concluded that current CIB systems 
are capable of significantly exceeding NCAP's current testing 
requirements. Thus, it is feasible to update the program's CIB test 
conditions to further safety improvements and address a greater number 
of rear-end crashes, particularly those which cause a greater number of 
injuries and fatalities in the real world.
c. AEB Effectiveness
    In its March 2022 RFC notice, NHTSA discussed findings from several 
studies suggesting that AEB systems (i.e., CIB and DBS) have 
collectively been effective in reducing rear-end crashes. As noted in 
the introductory section, UMTRI \75\ found that AEB systems

[[Page 95933]]

produced an estimated 46 percent reduction in applicable rear-end 
crashes when combined with a forward collision alert, which alone 
showed only a 21 percent reduction.\76\ Similarly, in a 2017 study, 
IIHS found that rear-end collisions decreased by 50 percent for 
vehicles equipped with AEB and FCW.\77\ Furthermore, a 2019 study 
conducted by IIHS \78\ suggested that the increasing effectiveness of 
AEB technology in certain crash situations, particularly those 
evaluated by NCAP and other consumer information programs, is changing 
the rear-end crash problem.
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    \75\ Leslie, A.J., Kiefer, R.J., Meitzner, M.R., & Flannagan, 
C.A. (2019, September), Analysis of the field effectiveness of 
General Motors production active safety and advanced headlighting 
systems, The University of Michigan Transportation Research 
Institute and General Motors LLC, UMTRI-2019-6.
    \76\ The AEB systems studied by UMTRI consisted of camera-only, 
radar-only, and fused camera-radar AEB systems, the latter two 
systems of which also included adaptive cruise control 
functionality.
    \77\ Cicchino, J.B. (2017, February), Effectiveness of forward 
collision warning and autonomous emergency braking systems in 
reducing front-to-rear crash rates, Accident Analysis and 
Prevention, 2017 Feb;99(Pt A):142-152, https://doi.org/10.1016/j.aap.2016.11.009.
    \78\ Cicchino, J.B. & Zuby, D.S. (2019, August), Characteristics 
of rear-end crashes involving passenger vehicles with automatic 
emergency braking, Traffic Injury Prevention, 2019, VOL. 20, NO. S1, 
S112-S118 https://doi.org/10.1080/15389588.2019.1576172.
---------------------------------------------------------------------------

    While these studies suggest that AEB systems (i.e., CIB and DBS) 
have collectively been effective in reducing rear-end crashes, NHTSA 
stated in its March 2022 notice that it was not clear how effective 
each of these systems is independently, or whether their individual 
effectiveness may change for certain crash scenarios, environmental 
conditions, or driver factors (e.g., poor judgement, distraction, 
etc.). The Agency also stated it is not aware of any studies of 
current-generation AEB systems that have determined the extent to which 
CIB and DBS individually contribute to crash reduction. Since NHTSA 
could not differentiate between the individual effectiveness of CIB and 
DBS systems, it tentatively concluded that NCAP should continue to 
assess CIB and DBS system performance individually and therefore retain 
DBS assessments. NHTSA explained that this approach would ensure 
vehicles would not suppress AEB operation in situations where the 
driver applies the vehicle's foundation brakes.\79\ However, as 
discussed later, the Agency also sought comment on removing the DBS 
test conditions from NCAP entirely in an effort to reduce test burden.
---------------------------------------------------------------------------

    \79\ Foundation brake system means all components of the service 
braking system of a motor vehicle intended for the transfer of 
braking application force from the operator to the wheels of a 
vehicle. See 49 CFR 579.4.
---------------------------------------------------------------------------

    The Agency did not perform DBS testing as part of its 
characterization study to evaluate system performance capabilities 
beyond what is currently required in NCAP's respective test procedure. 
However, DBS systems have historically been shown to impart additional 
braking beyond that afforded by CIB systems. NHTSA has observed 
complete crash avoidance in DBS tests but only speed reduction in the 
equivalent CIB tests conducted for the same vehicle models. Therefore, 
it was expected that DBS performance should typically be as good as, if 
not better than, CIB performance. NHTSA believed that it was fitting to 
align the proposed CIB and DBS evaluations for the assessed situations, 
since doing so would allow the Agency to evaluate whether a vehicle's 
DBS system would provide sufficient supplemental braking if the driver 
brakes but additional braking is warranted. To verify that equivalent 
performance requirements and criteria proposed for CIB would also be 
appropriate for DBS, NHTSA planned research tests for model year 2021 
and 2022 vehicles.
d. Model Year 2021 and 2022 Research Testing
    In accordance with its plans expressed in the March 2022 RFC, NHTSA 
conducted a series of AEB research tests in 2022 to further analyze 
current fleet performance.\80\ This testing, which involved 12 model 
year 2021 and 2022 light vehicles, included CIB and DBS testing in a 
variety of CIB and DBS test conditions. The goal of this research was 
to evaluate NHTSA's AEB proposals (found in subsequent sections) and to 
gain further knowledge regarding the capabilities of the current 
vehicle fleet.
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    \80\ https://www.regulations.gov/document/NHTSA-2023-0021-0005.
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    Both CIB and DBS tests were conducted in the LVS, LVM, LVD, and STP 
false positive scenarios. Additionally, NHTSA conducted two other false 
positive test scenarios as part of this research: a ``Pass Through'' 
test, in which the SV approaches two stationary lead vehicles located 
to the left and right of the SV forward path, and ``Pass Through + 
STP'' test, which is a combination of the STP and Pass Through 
scenarios.\81\ See Table 11 for the nominal test parameters used in 
this series of research tests. The ABD GVT Revision G, secured to a GST 
robotic platform (or carrier), was used as the POV for the model year 
2021 and 2022 research testing.
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    \81\ In the Pass Through + STP test, the SV approaches a large 
steel plate positioned longitudinally on the test surface in the 
forward path of the SV. Two stationary lead vehicles are located to 
the left and right of the STP in the SV forward path. The SV is 
driven over the STP, between the two lead vehicles.

                                     Table 11--Nominal Test Parameters for Model Year 2021 and 2022 Research Testing
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                       Test speeds (kph (mph))
               Test scenario                ---------------------------------------------    Headway  (m (ft.))    POV  decel.      CIB          DBS
                                                           SV                    POV                                   (g)
--------------------------------------------------------------------------------------------------------------------------------------------------------
Lead Vehicle Stopped (LVS).................  10, 40, 50, 60, 70, 80 (6.2,              0  .......................  ...........      [check]  ...........
                                              24.9, 31.1, 37.3, 43.5, 49.7).
                                             70, 80, 90, 100 (43.5, 49.7,              0  .......................  ...........  ...........      [check]
                                              55.9, 62.1).
Lead Vehicle Moving (LVM)..................  40, 50, 60, 70, 80 (24.9,         20 (12.4)  .......................  ...........      [check]  ...........
                                              31.1, 37.3, 43.5, 49.7).
                                             70, 80, 90, 100 (43.5, 49.7,      20 (12.4)  .......................  ...........  ...........      [check]
                                              55.9, 62.1).
Lead Vehicle Decelerating (LVD)............  50 (31.1).....................    50 (31.1)     12, 40 (39.4, 131.2)     0.4, 0.5      [check]      [check]
                                             80 (49.7).....................    80 (49.7)     12, 40 (39.4, 131.2)     0.4, 0.5      [check]      [check]
Steel Trench Plate (STP)...................  80 (49.7).....................  ...........  .......................  ...........      [check]      [check]
Pass Through...............................  80 (49.7).....................            0  .......................  ...........      [check]      [check]
Pass Through + Steel Trench Plate..........  80 (49.7).....................            0  .......................  ...........      [check]      [check]
--------------------------------------------------------------------------------------------------------------------------------------------------------

    For the LVS and LVM test series, SV speed was increased from lowest 
to highest. One initial trial was conducted per test speed. If no SV-
to-POV contact was observed, the next highest SV speed was run. 
However, if SV-to-POV contact

[[Page 95934]]

occurred and the SV speed at the time of impact was less than or equal 
to 50 percent of the initial SV speed, up to four additional (repeated) 
trials were performed at the same SV speed. If two additional SV-to-POV 
impacts were observed during the repeat sequence, the test series was 
terminated. Furthermore, if the SV speed at the time of impact was 
greater than 50 percent of the initial SV speed during the initial 
trial, no repeat runs were performed; testing for that scenario was 
terminated. For the LVD test series, testing proceeded in a similar 
manner. The SV speed was increased from lowest to highest, and POV 
deceleration was iteratively increased from 0.4g to 0.5g for a given 
speed combination and headway. Relevant outcomes of this research are 
detailed throughout the applicable sections of this notice.

D. NHTSA's Proposals, Summary of Comments, Response to Comments, and 
Agency Decisions

1. AEB
a. Forward Collision Prevention Technologies Inclusion in General
    Many commenters, including the NTSB, Bosch, HMNA, and NADA, 
expressed support for the Agency's proposed updates for NCAP's AEB 
testing. Additional proponents, such as the Advocates and QuantivRisk, 
Inc., cited the need for increased test stringency to realize 
additional safety benefits. In this vein, NTSB specifically asked NHTSA 
to ``strive for the performance we want the systems to be able to 
reach, not merely evaluate the current capabilities of the systems.'' 
Auto Innovators expressed a need for consistency between changes to 
NCAP and those planned for AEB standards. Other respondents, such as 
MEMA, appreciated the Agency's attempts to focus resources on emerging 
trends and harmonize its AEB test procedures with those used by 
European New Car Assessment Programme (Euro NCAP) and other consumer 
information programs. Toyota also supported the Agency's attempts at 
shared global assessments but recommended that NHTSA select (1) tests 
that can adequately ensure performance across a range of conditions to 
improve overall test efficiency and (2) performance criteria that 
reflect real-world benefits. Citing rising fatalities, several 
commenters requested that the Agency consider AEB test additions for 
cyclists and motorcyclists, while others mentioned current AEB system 
limitations, such as systems' inability to detect cyclists and other 
vulnerable road users (VRUs) at higher speeds and in low light and 
inclement weather.
b. AEB Test Procedure Changes, Including Higher Speeds and POV 
Deceleration Magnitude for LVD Test; and Removal of DBS Tests and Only 
High-Speed DBS Assessments
    NHTSA proposed harmonizing many aspects of changes to NCAP's CIB 
and DBS procedures with Euro NCAP's AEB Car-to-Car systems test 
protocol. The Agency reasoned this approach was most appropriate based 
on requirements of the BIL. The Agency also argued that it would be 
beneficial to standardize the current AEB test specifications with 
other consumer information programs, as doing so would allow the Agency 
and vehicle manufacturers to focus resources on emerging trends for 
rear-end crashes as AEB-equipped vehicles become more abundant in the 
fleet.\82\ NHTSA also noted it would consider making additional updates 
to its AEB test evaluation as the rear-end crash problem evolves.
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    \82\ Cicchino, J.B., & Zuby, D.S. (2019, August), 
Characteristics of rear-end crashes involving passenger vehicles 
with automatic emergency braking, Traffic Injury Prevention, 2019, 
VOL. 20, NO. S1, S112-S118, https://doi.org/10.1080/15389588.2019.1576172.
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    The updated CIB and DBS tests proposed in the 2022 RFC are detailed 
below for each test scenario. Tables 12 and 13 summarize the proposed 
test scenarios and conditions.

                      Table 12--CIB Test Scenarios and Conditions Proposed in the 2022 RFC
----------------------------------------------------------------------------------------------------------------
                                                        POV            POV
     Test  scenario         SV speed    POV speed   headway  (m   deceleration         Requirement to pass
                          (kph (mph))  (kph (mph))     (ft.))          (g)
----------------------------------------------------------------------------------------------------------------
LVS.....................    40 (24.9)            0          n/a             n/a  (1) No SV-to-POV contact on
                            50 (31.1)            0          n/a             n/a   first trial;
                            60 (37.3)            0          n/a             n/a  OR
                            70 (43.5)            0          n/a             n/a  (2) Any SV-to-POV contact where
                            80 (49.7)            0          n/a             n/a   the relative velocity between
                                                                                  the SV and POV is <= 50% of
                                                                                  initial SV speed
                                                                                 AND
                                                                                 No SV-to-POV contact in 3 out
                                                                                  of 5 total trials.
LVM.....................    40 (24.9)    20 (12.4)          n/a             n/a
                            50 (31.1)    20 (12.4)          n/a             n/a
                            60 (37.3)    20 (12.4)          n/a             n/a
                            70 (43.5)    20 (12.4)          n/a             n/a
                            80 (49.7)    20 (12.4)          n/a             n/a
LVD *...................    50 (31.1)    50 (31.1)    12 (39.4)             0.5
                            60 (37.3)    60 (37.3)    12 (39.4)             0.5
                            70 (43.5)    70 (43.5)    12 (39.4)             0.5
                            80 (49.7)    80 (49.7)    12 (39.4)             0.5
----------------------------------------------------------------------------------------------------------------
* For LVD, NHTSA requested comment on whether at least five of seven trials should be required for vehicles
  whose contact velocity is <=50 percent of the initial velocity, whether a 40 m headway should be included, and
  whether NHTSA should employ a 0.6g POV deceleration in lieu of 0.5g.


                      Table 13--DBS Test Scenarios and Conditions* Proposed in the 2022 RFC
----------------------------------------------------------------------------------------------------------------
                                                         POV           POV
      Test  scenario         SV speed    POV speed   headway  (m  deceleration         Requirement to pass
                           (kph (mph))  (kph (mph))     (ft.))         (g)
----------------------------------------------------------------------------------------------------------------
LVS **...................    70 (43.5)            0          n/a           n/a  (1) No SV-to-POV contact on
                             80 (49.7)            0          n/a           n/a   first trial;
                                                                                OR
                                                                                (2) Any SV-to-POV contact where
                                                                                 the relative velocity between
                                                                                 the SV and POV is <=50% of
                                                                                 initial SV speed
                                                                                AND
                                                                                No SV-to-POV contact in 3 out of
                                                                                 5 total trials.
LVM **...................    70 (43.5)    20 (12.4)          n/a           n/a
                             80 (49.7)    20 (12.4)          n/a           n/a

[[Page 95935]]

 
LVD ***..................    70 (43.5)    70 (43.5)    12 (39.4)           0.5
                             80 (49.7)    80 (49.7)    12 (39.4)           0.5
----------------------------------------------------------------------------------------------------------------
* For all DBS conditions, NHTSA requested comment on removal of all DBS test conditions.
** For LVS and LVM, NHTSA requested comment on the additional inclusion of 40, 50, and 60 kph (24.9, 31.1, and
  37.3 mph).
*** For LVD, NHTSA requested comment on the additional inclusion of 50 and/or 60 kph (31.1 and/or 37.3 mph) SV/
  POV speeds or only 70 and 80 kph (43.5 and 49.7 mph) (if they were adopted for CIB as well). NHTSA also
  requested comment on whether at least five of seven trials should be required to satisfy the performance
  requirement for vehicles whose relative velocity at contact is <=50 percent of the initial SV speed, whether
  40 m headway should be included, and whether NHTSA should employ 0.6g POV deceleration in lieu of 0.5g.

Crash Imminent Braking (CIB)
Lead Vehicle Stopped (LVS)
    Currently, NCAP's CIB LVS test is conducted at a speed of 40.2 kph 
(25 mph). In its upgrade proposal, the Agency recommended assessing CIB 
system performance over a range of test speeds for this test scenario. 
Specifically, NHTSA proposed a minimum SV test speed of 40 kph (24.9 
mph) (similar to that currently specified in NHTSA's CIB test 
procedure) and a maximum SV test speed of 80 kph (49.7 mph). NHTSA also 
proposed increasing the SV test speed in 10 kph (6.2 mph) increments 
from the minimum test speed to the maximum test speed for the LVS 
assessment, performing one trial per speed. To achieve a passing result 
for each speed, NHTSA proposed that the test trial must be valid (all 
test specifications and tolerances satisfied), and the SV must not 
contact the POV. Further, the Agency proposed that it would conduct 
four additional trials for any specific test speed that resulted in a 
test failure (i.e., contact) as long as the SV relative velocity at 
impact was less than or equal to 50 percent of the initial SV speed. 
For these five trials (i.e., one failed trial and four additional 
trials), NHTSA proposed that the SV must avoid contact with the POV for 
at least three trials to pass the test condition (i.e., combination of 
test scenario and test speed).
    In justifying its recommendation to incorporate higher test speeds 
for the LVS scenario, in addition to Volpe's real-world data analysis, 
which illustrated the safety need, the Agency indicated its CIB 
characterization testing demonstrated that several vehicles repeatedly 
afforded full crash avoidance (i.e., no contact) at speeds up to 72.4 
kph (45 mph) when subjected to this test. Further, NHTSA recognized 
that Euro NCAP's Car-to-Car Rear stationary (CCRs) scenario, which is 
comparable to the Agency's LVS test, is conducted at speeds as high as 
80 kph (49.7 mph) in the ``AEB only'' test condition. NHTSA reasoned 
that Euro NCAP's use of higher test speeds suggests higher test speeds 
are, from the perspective of test conduct, practicable for NCAP's LVS 
test as well.\83\ The Agency believed it was appropriate to harmonize 
with Euro NCAP on the maximum LVS test speed of 80 kph (49.7 mph), as 
this should better address the higher severity, high-speed crash 
problem and, in turn, further reduce fatalities and serious injuries. 
However, NHTSA did not propose to harmonize with Euro NCAP's protocol 
on the minimum SV test speed. Euro NCAP's CCRs scenario specifies a 
minimum SV speed of 10 kph (6.2 mph) for AEB systems, but the Agency 
stated it did not see the need to conduct its updated LVS testing at a 
speed less than that which is specified in its existing test procedure 
(40.2 kph (25 mph)). As such, a minimum test speed of 40 kph (24.9 mph) 
was proposed instead.
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    \83\ European New Car Assessment Programme (Euro NCAP) (April 
2021), Test Protocol--AEB Car-to-Car systems, Version 3.0.3. See 
section 8.2.3.
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    The Agency sought comment on whether the proposed speeds and 
overall assessment approach were appropriate for LVS or whether 
alternatives should be considered.
Lead Vehicle Moving (LVM)
    As mentioned previously, NCAP's CIB test procedure currently 
includes two LVM test conditions: a lower speed assessment that 
specifies an SV speed of 40.2 kph (25 mph) and POV speed of 16.1 kph 
(10 mph), and a higher speed assessment that prescribes an SV speed of 
72.4 kph (45 mph) and POV speed of 32.2 kph (20 mph). For this NCAP 
update, NHTSA proposed to assess CIB system performance over a range of 
SV test speeds for the LVM scenario. Similar to its proposal for the 
LVS scenario, NHTSA proposed to implement a ``no contact'' performance 
criterion for the LVM scenario and to increase the SV test speed for 
the LVM assessment in 10 kph (6.2 mph) increments from a minimum speed 
of 40 kph (24.9 mph) to a maximum speed of 80 kph (49.7 mph), with a 
POV speed of 20 kph (12.4 mph) for every SV test speed. The Agency also 
proposed to perform one trial run per speed and four additional trials 
for any specific test speed that resulted in a test failure for initial 
runs where the SV had a relative velocity at impact less than or equal 
to 50 percent of the initial SV speed. Similar to its proposal for LVS, 
the Agency proposed that the SV must not contact the POV for at least 
three out of the five test trials performed at that same speed to pass 
the LVM test condition.
    The Agency noted that the proposed minimum SV test speed of 40 kph 
(24.9 mph) is nearly equivalent to the speed currently specified for 
its lower speed LVM assessment, 40.2 kph (25 mph), and the proposed 
maximum SV test speed of 80 kph (49.7 mph) is only slightly higher than 
the speed specified for its higher speed LVM assessment, 72.4 kph (45 
mph). Since NCAP's higher speed CIB LVM assessment (conducted at an SV 
speed of 72.4 kph (45 mph) and POV speed of 32.2 kph (20 mph)) showed 
that many vehicles were able to stop without contacting the POV test 
device for each of the required test trials, NHTSA believed it was 
reasonable to raise the SV speed in NCAP's LVM test even though it had 
not performed additional LVM testing as part of its characterization 
study. The Agency also noted that Euro NCAP performs its Car-to-Car 
Rear moving (CCRm) scenario (which is comparable to NCAP's LVM tests) 
at speeds as high as 80 kph (49.7 mph), further suggesting that higher 
SV test speeds are practicable.\84\ Given this, NHTSA believed it was 
appropriate to harmonize with Euro NCAP on the maximum SV test speed of 
80 kph (49.7 mph) for the Agency's LVM test. NHTSA reasoned that 
adopting a higher maximum SV test speed than that which is currently 
required in the Agency's CIB procedure should encourage improved CIB 
system performance at higher speeds, and thus further reduce fatalities 
and serious injuries.
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    \84\ European New Car Assessment Programme (Euro NCAP) (April 
2021), Test Protocol--AEB Car-to-Car systems, Version 3.0.3. See 
section 8.2.4.
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    Although it proposed to harmonize with Euro NCAP's protocol with 
respect to the maximum SV speed adopted for

[[Page 95936]]

its LVM test, the Agency did not suggest harmonizing with Euro NCAP 
with respect to the minimum required SV test speed. Euro NCAP's CCRm 
scenario specifies a minimum SV test speed of 30 kph (18.6 mph) for 
AEB-equipped vehicles; however, the Agency did not believe there was 
not a compelling reason to perform its updated LVM test at a speed that 
is less than the current required test speed (i.e., 40.2 kph (25 mph)) 
since most vehicles have been able to meet NCAP's current LVM test 
requirements at 40.2 kph (25 mph) to date with a similar POV test 
speed. Accordingly, NHTSA proposed a minimum SV test speed of 40 kph 
(24.9 mph).
    NHTSA proposed to adopt a POV test speed of 20 kph (12.4 mph). The 
Agency noted this POV speed is specified in Euro NCAP's CCRm protocol, 
and therefore adopting this speed for NHTSA's LVM testing seemed 
appropriate since it would further support harmonization efforts.
    Comments were requested on whether the SV/POV speeds and assessment 
approach proposed for NCAP's CIB LVM tests were appropriate or whether 
alternative speeds or approaches should be considered instead.
Lead Vehicle Decelerating (LVD)
    For the LVD scenario, NHTSA proposed to reduce the minimum nominal 
SV and POV test speeds from 56 kph (34.8 mph), as specified in NCAP's 
test procedure, to 50 kph (31.1 mph), as stated in Euro NCAP's AEB Car-
to-Car systems test protocol, Version 3.0.3, dated April 2021 for the 
Car-to-Car rear braking (CCRb) scenario.\85\ The Agency stated that, 
given additional changes proposed for the SV-to-POV headway and 
deceleration magnitude for the LVD scenario, the proposed reduction in 
test speed would not lead to an overall reduction in test stringency or 
loss of safety benefits. NHTSA requested comment on whether this 
proposed test speed change was appropriate for NCAP's LVD testing.
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    \85\ European New Car Assessment Programme (Euro NCAP) (April 
2021), Test Protocol--AEB Car-to-Car systems, Version 3.0.3. See 
section 8.2.5.
---------------------------------------------------------------------------

    The Agency also sought comment on whether it would be appropriate 
to incorporate additional SV and POV test speeds for the LVD test 
scenario: 60, 70, and 80 kph (37.3, 43.5, and 49.7 mph, respectively). 
Similar to the proposed CIB LVS and LVM test scenarios, NHTSA proposed 
to concurrently increase the SV and POV test speeds in 10 kph (6.2 mph) 
increments from the minimum test speed to the maximum test speed for 
NCAP's LVD assessment if multiple speeds were adopted. The Agency also 
proposed, as discussed in a later section, to perform one trial run per 
speed and four additional trials for any specific test speed that 
resulted in a test failure (i.e., SV-to-POV contact) where the SV had a 
relative velocity at impact less than or equal to 50 percent of the 
initial SV speed. Like the other two CIB test scenarios, the Agency 
proposed the SV must not contact the POV for at least three out of the 
five test trials performed at that same speed to pass the test 
condition. Alternatively, the Agency sought comment on whether testing 
at only 50 kph (31.1 mph) and 80 kph (49.7 mph) would be acceptable.
    NHTSA acknowledged in its proposal that it had not yet performed 
LVD testing at 80 kph (49.7 mph), mainly due to equipment and test 
track length limitations, as this test scenario requires that both the 
SV and POV be travelling at the same speed at the onset of the test 
validity period. However, the Agency recognized that higher speed tests 
may be warranted. For instance, Volpe's analysis of the 2011-2015 FARS 
data set showed that, when posted speed limit was known, the majority 
of fatal rear-end crashes (71 percent) occurred on roads with posted 
speeds exceeding 72.4 kph (45 mph). Considering the braking performance 
observed during the high-speed LVS tests conducted as part of its 
characterization study, the Agency noted current vehicles may perform 
well in LVD tests conducted at even higher speeds. Additionally, NHTSA 
believed that CIB systems may be able to classify POVs more confidently 
in the LVD test compared to the LVS test due to the POV's detected 
motion (i.e., path history). Accordingly, NHTSA conducted research to 
assess vehicles' CIB system performance in the LVD test at SV and POV 
speeds ranging from 50 kph (31.1 mph) to 80 kph (49.7 mph) to determine 
the feasibility of adopting one or more of these speeds for this test 
scenario.\86\
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    \86\ The Agency proposed these speeds would each be assessed for 
both 12 and 40 m (39.4 and 131.2 ft.) headways and POV deceleration 
magnitudes of 0.4g and 0.5g.
---------------------------------------------------------------------------

    In its March 2022 RFC notice, NHTSA also proposed to reduce the 
minimum nominal SV-to-POV headway of 13.8 m (45.3 ft.), currently 
specified for the LVD scenario, to 12 m (39.4 ft.) for the proposed 
test speed of 50 kph (31.1 mph). Although not assessed as part of its 
CIB characterization testing, the Agency asserted this change would not 
only harmonize with Euro NCAP's CCRb scenario with respect to test 
conduct, but also maintain similar stringency to NCAP's current LVD 
test scenario, given the proposed test speed reduction from 56 kph 
(34.8 mph) to 50 kph (31.1 mph). Euro NCAP also specifies an additional 
SV-to-POV headway of 40 m (131.2 ft.); however, the Agency did not 
propose to conduct this assessment as part of the RFC, as NHTSA 
suggested there would not be a safety benefit in adopting 40 m (131.2 
ft.) as an additional, and presumably less stringent, headway. 
Therefore, the Agency did not want to increase the test burden 
unnecessarily. However, the Agency indicated that it would assess 
vehicle performance at both 12 and 40 m (39.4 and 131.2 ft.) headways 
as part of its future research for each of the test speeds to be 
evaluated. The Agency also sought public comment on which SV-to-POV 
headway(s) may be appropriate for adoption not only for the proposed 
test speed (i.e., 50 kph (31.1 mph)), but also for each of the 
additional test speeds (ranging from 60 kph (37.3 mph) to 80 kph (49.7 
mph)) it planned to evaluate and possibly incorporate.
    The last change the Agency proposed for the LVD test scenario was 
increasing the POV deceleration magnitude currently specified in its 
CIB test procedure from 0.3g to 0.5g. In the Agency's CIB 
characterization study, three vehicles repeatedly afforded full crash 
avoidance (i.e., no contact) for all trials when the POV executed a 
0.5g braking maneuver in the LVD condition with an SV test speed of 
56.3 kph (35 mph) and SV-to-POV headway of 13.8 m (45.3 ft.), 
demonstrating that the change to POV deceleration for the revised LVD 
test conditions (which also includes a slightly lower test speed and 
slightly shorter SV-to-POV headway) is likely feasible. The Agency also 
noted that, in Euro NCAP's AEB Car-to-Car systems test protocol, the 
organization specifies POV deceleration magnitudes of 2 m/s\2\ and 6 m/
s\2\ (approximately 0.2 and 0.6g) for its CCRb scenario.\87\ As such, 
NHTSA reasoned that adopting a 0.5g POV deceleration magnitude would be 
practicable. To verify this assumption, as part of its research study, 
NHTSA committed to evaluating POV deceleration magnitudes of both 0.4 
and 0.5g for the range of test speeds considered (i.e., 60, 70, and/or 
80 kph (37.3, 43.5, and/or 49.7 mph)) for future LVD testing.\88\ The 
Agency also sought comment on what deceleration magnitude(s) would be 
appropriate for the proposed test speed (i.e., 50 kph

[[Page 95937]]

(31.1 mph)), as well as each of these additional test speeds.
---------------------------------------------------------------------------

    \87\ European New Car Assessment Programme (Euro NCAP) (), Test 
Protocol--AEB Car-to-Car systems, Version 3.0.3. See section 8.2.5.
    \88\ NHTSA notes that the LVD research tests were conducted only 
for 50 and 80 kph (31.1 and 49.7 mph) test speeds.
---------------------------------------------------------------------------

    NHTSA did not propose a 0.6g POV deceleration magnitude for use in 
its LVD test, even though Euro NCAP specifies 0.6g as the maximum POV 
deceleration for its CCRb scenario. In proposing 0.5g as the maximum 
POV deceleration in lieu of 0.6g, the Agency stated a lower POV 
deceleration may reduce equipment wear, particularly for the tires and 
braking components of the POV propulsion system, thus improving test 
efficiency. Specifically, NHTSA explained it has observed instances 
where the tires of the low-profile robotic vehicle (LPRV) platform \89\ 
used to move the GVT developed flat spots while performing a braking 
maneuver similar to that specified in the Agency's CIB LVD test \90\ 
but with higher POV decelerations. During this testing, NHTSA also 
found it was more difficult to achieve and accurately control POV 
deceleration within prescribed tolerances when braking maneuvers higher 
than 0.5g were used, even with extensive LPRV tuning efforts.\91\ The 
Agency noted that a deceleration of 0.6g is not only very close to the 
maximum braking capability of the LPRV, but also very close to the 
default magnitude used by the LPRV during an emergency stop (maximum 
deceleration). However, NHTSA acknowledged that newer robotic platforms 
(i.e., robotic carriers) offering greater capabilities are now becoming 
available, and they may resolve the issues observed in the Agency's 
testing. Accordingly, NHTSA requested comment on whether it may now be 
feasible to adopt a POV deceleration magnitude of 0.6g in lieu of 0.5g, 
as proposed.
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    \89\ The GVT is secured to the top of the LPRV. The LPRV is 
responsible for any movement of the GVT during test conduct.
    \90\ Fogle, E. E., Arquette, T. E. (TRC), and Forkenbrock, G. J. 
(NHTSA), (2021, May), Traffic Jam Assist Draft Test Procedure 
Performability Validation (Report No. DOT HS 812 987), Washington, 
DC: National Highway Traffic Safety Administration.
    \91\ From Section 4.1 of DOT HS 812 987: ``POV deceleration 
validity check failures occurred during six trials of the eight 
LVDAD trials performed. Four of the seven 0.6 g failures were 
because the POV was unable to achieve the minimum deceleration 
threshold of 0.55 g. The remaining three 0.6 g failures were because 
the POV was unable to maintain a minimum average deceleration of at 
least 0.55 g.'' Here, LVDAD refers to ``Lead Vehicle Accelerates, 
Decelerates, then Decelerates.'' The LVDAD test is a more complex 
variant of the LVD test and was used by NHTSA to perform traffic jam 
assist research.
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Dynamic Brake Support (DBS)
    With respect to DBS, the Agency proposed to align all test 
conditions (e.g., SV and POV test speed(s), headway(s), POV 
deceleration magnitude(s), etc.) for the comparable LVD, LVM, and LVS 
test scenarios with those proposed for CIB. Likewise, NHTSA proposed a 
similar performance criterion (i.e., no contact) and assessment 
approach as well; when applicable, speeds would be increased in 10 kph 
(6.2 mph) increments from the minimum test speed to the maximum test 
speed, with one trial performed per speed, and four additional trials 
conducted for any specific test speed that resulted in a test failure 
(i.e., contact) as long as the SV had a relative velocity at impact 
less than or equal to 50 percent of the initial SV speed. Similar to 
CIB, the Agency proposed that the SV must avoid contact with the POV 
for at least three out of the five test trials performed at that same 
speed to pass the test condition (if the vehicle fails the initial 
trial at a given test speed).
    Although the Agency had not conducted DBS testing as part of its 
characterization study to evaluate system performance capabilities 
beyond what is currently required in NCAP's DBS test procedure, NHTSA 
believed it was nonetheless fitting to align the proposed CIB and DBS 
evaluations, as it would allow NHTSA to assess whether a vehicle's DBS 
system will provide supplemental braking if the driver manually applies 
a brake pedal input but additional braking is warranted to afford crash 
avoidance. Further, the Agency noted its CIB and DBS test procedures 
are currently aligned with respect to test scenarios, test speeds, 
headways, etc. Differences exist only with respect to the use of manual 
brake application (i.e., for the SV in DBS testing) and (most) 
performance criteria.\92\ Therefore, the Agency reasoned it would be 
appropriate to adopt the CIB test conditions (i.e., test speeds, 
headways, etc.) for the comparable DBS test conditions for future 
testing as well. NHTSA requested comments on whether this proposal for 
future DBS testing, including the assessment method, was appropriate.
---------------------------------------------------------------------------

    \92\ NHTSA's DBS test procedure currently specifies ``no 
contact'' as the performance criterion for all DBS test conditions, 
whereas the Agency's CIB test procedure currently requires a 
specified speed reduction for each of the CIB test conditions (with 
the exception of the lower speed LVM condition where the POV speed 
is 16.1 kph (10 mph) and the SV speed is 40.2 kph (25 mph), which 
requires ``no contact.''
---------------------------------------------------------------------------

    The Agency also sought comment on removing the LVD, LVM, and LVS 
DBS test conditions from NCAP entirely (in addition to the false 
positive test conditions, discussed later) to reduce test burden and 
associated costs given findings from Volpe's analysis of the 2011-2015 
FARS and GES data sets and other changes NHTSA proposed for its CIB 
assessments.
    Specifically, Volpe found that the driver braked in just 8 percent 
of rear-end crashes involving fatalities and in 20 percent of those 
crashes involving injuries. The study also showed that the driver made 
no attempt to avoid the crash (e.g., no braking, steering, 
accelerating) for 56 percent of crashes involving fatalities and for 21 
percent of those involving injuries.\93\ These findings were contrary 
to those documented by NHTSA during a review of 2003-2009 National 
Automotive Sampling System Crashworthiness Data System data to define 
the target population for rear-end crashes.\94\ For that analysis, the 
Agency concluded that the driver braked in approximately half of the 
crashes and did not brake in the other half, which lends merit to 
performing both CIB and DBS tests. The Agency believed it was possible 
the brake application rates differed in the two studies because of (1) 
target crash population refinements made for NHTSA's original analysis 
and (2) differences in data collection methods between the crash 
databases. For instance, high-speed crashes were excluded from NHTSA's 
target crash population review because the AEB systems tested at the 
time had limited speed reduction capabilities.
---------------------------------------------------------------------------

    \93\ The Agency notes that for the rear-end pre-crash scenario 
group, the driver avoidance maneuver was unknown in 25 percent and 
54 percent of the FARS and GES crashes, respectively. When excluding 
cases where a driver avoidance maneuver was unknown, the driver made 
no attempt to avoid the crash in 75 percent and 48 percent of the 
FARS and GES crashes, respectively. Likewise, when a driver's 
avoidance maneuver was known, the driver braked in 11 percent of 
FARS crashes and 45 percent of GES crashes.
    \94\ National Highway Traffic Safety Administration (2012, 
June), Forward-looking advanced braking technologies research 
report, https://www.regulations.gov/document?D=NHTSA-2012-0057-0001.
---------------------------------------------------------------------------

    As previously mentioned, NHTSA proposed to adopt a more stringent 
``no contact'' performance criterion for each of NCAP's CIB test 
conditions. The Agency's existing CIB test procedure requires a 
specified speed reduction for each of the CIB test conditions (with the 
exception of the lower speed LVM condition, which requires ``no 
contact''), whereas the DBS test procedure currently specifies ``no 
contact'' as the performance criterion for all DBS test conditions. The 
proposed change for CIB would effectively align the CIB performance 
requirements with those currently specified for DBS, and NHTSA 
questioned whether it was necessary to continue performing DBS tests in 
NCAP given public comments previously

[[Page 95938]]

received. For example, in its comments to NCAP's December 2015 notice, 
the Alliance \95\ stated that since crash avoidance (i.e., no SV-to-POV 
contact) is the desired outcome for all imminent rear-end crash events, 
if an SV avoids contact with the POV in all CIB tests, DBS testing 
should not be necessary. The Agency agreed with the Alliance's 
rationale in principle but questioned whether there would be merit to 
ensuring both AEB systems perform as designed and help the driver to 
mitigate or prevent the crash. NHTSA hypothesized that it may be 
possible for the driver to apply the brakes but with a magnitude that 
does not result in achieving the vehicle's maximum crash avoidance 
potential (i.e., deceleration). Further, the Agency explained that, in 
the past, some manufacturers had assumed the driver was in control when 
the brake pedal was depressed, and designed CIB systems such that 
automatic braking was overridden by the driver's input, even when the 
driver's braking was insufficient to avoid a crash. Based on this 
reasoning, NHTSA explained it was hesitant to assume that if a 
vehicle's CIB system works effectively during testing, its DBS system 
would automatically do so as well.
---------------------------------------------------------------------------

    \95\ Alliance of Automobile Manufacturers (The Alliance) merged 
with Global Automakers in January 2020 to create the Alliance for 
Automotive Innovation (Auto Innovators). Both automotive industry 
groups separately submitted comments to the December 2015 notice.
---------------------------------------------------------------------------

    Thus, as an alternative to removing the DBS performance evaluations 
from NCAP entirely (or retaining the LVD, LVM, and LVS DBS tests in 
NCAP, as proposed), the Agency concluded that it might be more 
reasonable to conduct only LVS and LVM DBS tests in NCAP at the highest 
two test speeds proposed for CIB--70 and 80 kph (43.5 and 49.7 mph, 
respectively)--to ensure (1) the DBS system functions properly at these 
speeds and (2) the SV will not suppress AEB operation when the driver 
applies the vehicle's foundation brakes. The Agency further noted that 
it would also consider conducting the DBS LVD test at only 70 and 80 
kph (43.5 and 49.7 mph, respectively) if it decided to adopt those same 
higher test speeds for the CIB LVD test. Comments were requested on 
this alternative proposal and whether an alternative assessment method 
would be more appropriate if any or all of the DBS test scenarios were 
conducted only at the two highest test speeds.
Summary of Comments
Regarding NHTSA's AEB Proposal, In General
    Several commenters, including BMW, FCA, and Honda, supported the 
Agency's proposal for CIB and DBS with respect to SV and POV speeds, 
headway distances, and POV deceleration magnitudes. FCA stated that the 
proposal was appropriate because it reflects current system 
capabilities and real-world crashes. With the exception of suggested 
changes for the LVD scenario, discussed later, Tesla also generally 
agreed with the Agency's proposal with respect to test speeds, headway, 
and deceleration magnitudes for CIB testing and the general intent to 
harmonize with Euro NCAP test protocols. Specifically, Tesla supported 
conducting LVS and LVM scenarios at test speeds ranging from 40 to 80 
kph (24.9 and 49.7 mph) with 10 kph (6.2 mph) increments, as proposed. 
Auto Innovators also generally agreed with the proposed test 
requirements but suggested the Agency harmonize with Euro NCAP and 
conduct CIB testing up to 50 kph (31.1 mph) and DBS testing at speeds 
over 50 kph (31.1 mph).
    Like Tesla, Advocates and Bosch also supported generally 
harmonizing the Agency's CIB testing with that performed by Euro NCAP, 
but with small variations. Advocates supported aligning the LVM and LVS 
POV and SV speeds with those used by Euro NCAP but did not support the 
Agency's justification for not aligning minimum test speeds for these 
two scenarios with those prescribed by Euro NCAP (10 kph, or 6.2 mph) 
as being sufficient. Bosch also mentioned harmonization with respect to 
test speeds but suggested the Agency should further investigate whether 
there is merit to increasing test speeds to assess AEB systems.
    Conversely, GM opposed any change to the test conditions prescribed 
in the Agency's current CIB test procedure. The automaker stated that 
the current AEB test speeds show significant real-world safety benefits 
\96\ and, as documented in DOT HS 811 521A, ``Objective Tests for 
Automatic Crash Imminent Braking (CIB) Systems,'' the current test 
parameters are ``well-supported by field crash scenarios most relevant 
to these features and associated with the highest societal harm, as 
measured by Functional Years Lost.''
---------------------------------------------------------------------------

    \96\ See GM Appendix 1.
---------------------------------------------------------------------------

    Other commenters suggested that the Agency remove certain test 
conditions. Auto Innovators suggested that the Agency remove one of the 
two original LVM scenarios, preferably the lower speed condition (i.e., 
SV and POV speeds of 40 and 16 kph (25 and 10 mph), respectively), 
since real-world data shows only 2 percent of fatalities and 6 percent 
of injuries occur on roads having posted speed limits of 40 kph (25 
mph) or less. Similarly, Toyota stated that the Agency should adopt 
only the number of test conditions sufficient to communicate accurate 
performance information to consumers. The automaker suggested that, if 
testing only at a certain speed would ensure performance for a large 
speed range, then that approach was acceptable for testing.
    With respect to other procedural considerations, Subaru recommended 
that NHTSA adopt a speed increment of 20 kph (12.4 mph) in lieu of 10 
kph (6.2 mph) for LVM testing. A few other respondents also generally 
supported the test parameters, but suggested slight modifications, 
which are addressed later in this section.
Adopt Higher AEB Test Speeds Than Those Proposed
    State Farm, IIHS, and Uhnder supported CIB and DBS testing at 
higher speeds, stating that such speeds better reflect real-world 
driving conditions. Uhnder supported adoption of test speeds that 
exceed 88.5 kph (55 mph), citing a May 2022 study from IIHS finding 
nearly 70 percent of fatal rear-end crashes occurred when the speed 
limit was 88.5 kph (55 mph) or higher.\97\ Similarly, IIHS noted that 
nearly 80 percent of police-reported rear-end crashes occurred on roads 
having speed limits ranging from 48.3 to 104.6 kph (30 to 65 mph),\98\ 
and the speed of the striking vehicle was more than 40 kph (24.9 mph), 
even on roads with speed limits of 40.2 kph (25 mph).\99\
---------------------------------------------------------------------------

    \97\ See footnote 11 of Uhnder response.
    \98\ Kidd, 2022a.
    \99\ Kidd, 2022b.
---------------------------------------------------------------------------

    Adasky, NTSB, and CAS also favored higher speed AEB assessments 
than those proposed. CAS asserted that NHTSA should conduct CIB tests 
at the highest speeds possible to still afford safe testing so that 
consumers may identify vehicles offering superior CIB performance at 
each test speed. Similarly, NTSB encouraged NHTSA to consider more 
challenging test speeds to drive desired (i.e., ideal) system 
performance instead of testing to current system capabilities. Finally, 
Rivian also suggested adopting higher speeds for DBS tests than those 
proposed if the Agency continued DBS testing in the future.

[[Page 95939]]

Test Speeds and Headway for the LVD Test Scenario Specifically
    Several commenters favored adopting AEB test speeds up to 80 kph 
(49.7 mph) for the LVD test scenario, with BMW and Honda stating that 
these test speeds were appropriate since they were supported by crash 
data.
    Tesla, along with Subaru, recommended conducting LVD scenarios at 
50 kph (31.1 mph), as proposed (similar to Euro NCAP), and also at 80 
kph (49.7 mph), as suggested by NHTSA. Subaru added that, if a test 
failure occurs at 80 kph (49.7 mph), the test speed should then be 
reduced by 10 kph (6.2 mph). Advocates favored harmonization with Euro 
NCAP with respect to test speed, headway, and deceleration for the LVD 
scenario, but preferred NHTSA's alternative proposal of adopting 
multiple higher test speeds (above 50 kph (31.1 mph)), suggesting NHTSA 
should also include a ``range of test speeds'' based on crash data and 
the Agency's testing.
    Toyota encouraged NHTSA to conduct additional feasibility studies 
and research, particularly for the LVD test scenario, to: (1) resolve 
possible GVT stability issues; (2) study the possible conflict with 
human driver steering avoidance maneuver timing; and (3) research the 
effectiveness of FCW and DBS based on the physical limitations imposed 
by the proposed LVD DBS test condition, and, considering driver 
reaction times, determine whether such higher-speed testing is feasible 
and appropriate before modifying the AEB test conditions. With respect 
to the first request, Toyota noted the Agency's statement that it has 
not conducted CIB/DBS LVD testing at 80 kph (49.7 mph) because of 
equipment and test track length limitations. Regarding its second 
point, the automaker asserted that the time required to steer to avoid 
a collision at higher speeds is less than the time required to brake, 
and that by imposing the suggested high speed CIB test conditions, the 
Agency may create a challenging `braking' situation that could 
interfere with a driver's ability to avoid the crash by steering 
instead. Lastly, Toyota voiced concern that the SV and POV dynamics for 
DBS LVD testing at higher speeds may pose physical limitations.\100\ 
More specifically, for speeds of 50 kph (31.1 mph) and greater, the 
manufacturer asserted that, given the (constant) headway prescribed, 
the time (i.e., TTC) required to activate the brake to avoid impact, 
and the proposed brake application timing of 1.0 s after issuance of 
the FCW, it is possible the FCW would have to be issued before the POV 
test device begins to decelerate in the DBS test for the SV to avoid 
contact with the POV. Toyota was supportive of DBS testing at higher 
speeds for the LVS test scenario.
---------------------------------------------------------------------------

    \100\ See case study included in Toyota's comments.
---------------------------------------------------------------------------

    Intel shared Toyota's concerns about the LVD DBS tests, explaining 
the proposed headway (12 m (39.4 ft.)) may be too small given a POV 
deceleration of 0.5 to 0.6g, such that it may not be possible to issue 
the FCW early enough to achieve brake activation one second after the 
issuance of the FCW as NHTSA proposed for the test procedure. Intel 
also cautioned the Agency that it should ensure it is feasible for test 
labs to conduct LVD tests at the proposed higher speeds considering the 
GVT platform experiences performance degradation at high speeds. Intel 
further noted many automakers limit speed reductions to approximately 
60 kph (37.3 mph) per Automotive Safety Integrity Level (ASIL) 
considerations.
    Auto Innovators did not support the Agency's adoption of test 
speeds exceeding the capabilities afforded by current systems for the 
LVD test condition because it may induce false positives under real-
world driving conditions, which may in turn discourage AEB use. The 
group, like Toyota, also cautioned that the proposed high-speed testing 
may cause unexpected interactions between the SV and POV during 
testing. Auto Innovators recommended that the Agency consider the 
proposed changes for CIB and DBS for future program updates to (1) 
allow additional time to investigate the field relevance of the 
proposed changes for both technologies and (2) provide sufficient time 
for system capabilities to improve.
    To better align with Euro NCAP testing, Intel suggested that LVD 
testing should be limited to 50 kph (31.1 mph) and should be performed 
only for vehicles equipped with both AEB and FCW. HATCI recommended 
that the Agency harmonize with the test speeds prescribed in Euro 
NCAP's protocol for the LVD test scenario if it ultimately adopts 
higher test speeds, and asked that the SV-to-POV headway be increased 
for each higher speed test condition based on field-representative 
distances or TTCs. Subaru recommended that the Agency maintain vehicle 
headway in LVD testing at a spacing equivalent to 1.0 second (instead 
of 12 m (39.4 ft.), as proposed) regardless of test speed. FCA also 
favored higher speed assessments for the LVD test scenario. However, 
FCA stated that the SV-to-POV headway should be adjusted for each speed 
to reflect a 0.9 second following distance, asserting this following 
distance is typical of real-world driving.
POV Deceleration Magnitude for LVD Test Scenario
    Most commenters addressing this issue favored a 0.5g POV 
deceleration for the LVD CIB test instead of 0.6g, with TRC citing 
issues with repeatability when attempting to tune the GVT braking 
system to operate at a deceleration greater than 0.5g. Although it 
acknowledged that new robotic platforms make tuning easier, TRC also 
suggested that they are expensive and require modification of existing 
equipment before they can be utilized. BMW also cited robotic platform 
operational limits and tire wear as reasons not to adopt a 0.6g POV 
deceleration requirement. HATCI favored a 0.5g deceleration magnitude 
because of proven repeatability and minimal equipment damage. The 
commenter recommended that the Agency increase the vehicle headway if 
it chooses to adopt a 0.6g POV deceleration instead.
    GM and Auto Innovators supported a 0.5g deceleration, asserting 
that this is a ``common'' deceleration level (based on crash data 
reviewed by NHTSA) and therefore ``realistic.'' Both commenters 
mentioned that a 0.6g deceleration has not been shown to induce 
differences in vehicle performance, but can cause problems with test 
equipment (based on experience in conducting Euro NCAP tests at 6 m/
s\2\). In a similar vein to the repeatability concerns mentioned by 
others, GM also noted that China NCAP no longer generally performs LVD 
tests (and other consumer groups are expected to follow suit) because 
they are difficult to conduct and test results for a given vehicle 
model are often widely variable.
    A few commenters expressed conditional support for the higher POV 
deceleration. Specifically, Honda and Auto Innovators offered support 
for adoption of a 0.6g deceleration if crash data indicates such a 
limit is more representative of driver braking in real-world crashes. 
Auto Innovators added that the Agency must also ensure testing 
tolerances. FCA suggested that a 0.6g deceleration may be acceptable if 
NHTSA wanted to ``reduce validation effort.''
    Intel expressed support for adopting a 0.6g deceleration criterion 
for the LVD CIB test to harmonize with other entities and regulations 
and thus reduce test burden. The company stated that, considering the 
tolerance currently prescribed for the POV deceleration, the

[[Page 95940]]

difference between 0.5g and 0.6g is small. Bosch also supported 
adoption of a 0.6g deceleration magnitude, as did Tesla. However, Tesla 
suggested that in lieu of a single POV deceleration of 0.5 or 0.6g, as 
proposed, the Agency should adopt deceleration magnitudes of -2 m/s\2\ 
and -6 m/s\2\ (approximately 0.2 and 0.6g), respectively, for each test 
speed to harmonize with Euro NCAP. Advocates shared this opinion.
Agree With Removal of DBS Tests
    MEMA, Subaru, and HATCI agreed with the Agency's proposal to remove 
the DBS test scenarios from NCAP's AEB test matrix, with the latter 
commenter suggesting that CIB and DBS functionality may overlap at 
certain speeds such that DBS functionality would be redundant when CIB 
is activated. HATCI therefore suggested that, if the Agency decided to 
continue conducting separate DBS assessments in NCAP, such tests should 
only be performed when a vehicle exhibits a test failure during CIB 
testing for that condition, as this would reduce test burden. Rivian 
remarked that the DBS testing was unnecessary because a vehicle's CIB 
system will activate and slow the vehicle when the braking imparted by 
DBS is insufficient. Subaru recommended removal or replacement of any 
ADAS test that currently has a high rate of passing results if adoption 
rates for the related ADAS technology are also high.
Retain Some or All DBS Tests
    Several commenters expressed that the Agency should continue to 
conduct DBS assessments in NCAP because DBS affords additional safety 
benefits compared to CIB. ZF Group favored retaining the DBS tests to 
ensure that vehicles continue to be equipped with DBS, noting that DBS 
systems ``can react earlier in critical situations.'' Similarly, CAS 
asserted that DBS ``can provide additional safety margin.''
    Other commenters recommended that NHTSA continue DBS testing to 
ensure system functionality. Advocates, GM, and Auto Innovators 
suggested the Agency should (Advocates and GM), or could (Auto 
Innovators), continue to conduct DBS tests to ensure that brake pedal 
application does not override AEB system functionality in general. NTSB 
also agreed that DBS functionality should be verified and supported 
NHTSA's alternative proposal to retain DBS testing in NCAP and conduct 
LVM and LVS testing at higher speeds (70 and 80 kph (43.5 and 49.7 
mph)).
    GM and Auto Innovators also recommended other options centered on 
performing DBS tests only at certain speeds that NHTSA could adopt to 
reduce the burden of DBS testing. GM noted that China NCAP performs CIB 
tests at lower speeds and DBS tests at higher speeds. The automaker 
suggested that for speeds higher than 40 kph (24.9 mph) the Agency 
could alternate between CIB and DBS testing. Auto Innovators stated 
that DBS testing would be unnecessary in situations where the CIB 
system provides complete avoidance in all tests, noting that the Agency 
could simply assume DBS performance and apply points for both systems 
equally. Auto Innovators also stated that each assessed test speed 
should afford equal weighting for both CIB and DBS, noting it should 
not be the case that one test speed carries twice the weight simply 
because both systems are assessed at that speed, whereas another test 
speed carries less weight because only one of the two systems is 
assessed at that speed. Both GM and Auto Innovators noted, similar to 
HATCI, that NHTSA could conduct CIB tests until the system can no 
longer provide full avoidance and then begin DBS testing for the next 
subsequent higher test speed. If the CIB system was able to provide 
complete avoidance at all test speeds, then the commenters suggested 
that DBS testing could be repeated for only the maximum test speed to 
ensure system functionality. GM also noted that for 2023 Euro NCAP 
removed the DBS tests for LVM and LVD from their assessment and going 
forward it will only perform the DBS test for the LVS scenario. 
Finally, Auto Innovators encouraged the Agency to reduce the number of 
test scenarios and evaluate FCW during DBS testing (i.e., record the 
time of the FCW) to further reduce test burden.
    Like other commenters' suggestions, FCA and Intel recommended that 
the Agency continue to perform DBS tests in NCAP for higher test speeds 
where the CIB system does not afford full crash avoidance, with Intel 
suggesting that it may be appropriate to start the DBS tests at 60 kph 
(37.3 mph) to harmonize with Euro NCAP. IDIADA also suggested that the 
Agency only perform higher speed DBS tests. Similarly, Toyota, like the 
NTSB, was supportive of the Agency conducting LVS and LVM DBS tests at 
only the highest test speeds proposed for CIB--70 and 80 kph (43.5 and 
49.7 mph), respectfully. However, Toyota did not support conducting the 
LVD DBS test at 80 kph (49.7 mph) since NHTSA stated that it had not 
conducted testing at this speed due to equipment and test track 
limitations. Intel expressed similar concerns, stating that 
manufacturers may not be able to issue the FCW early enough to achieve 
brake activation one second after the issuance of the FCW as NHTSA 
proposed for the LVD tests.
    Unlike those commenters who expressed that it was sufficient for 
the Agency to only conduct high-speed DBS assessments or alternate CIB 
and DBS assessments for incremental speeds, Honda stated that it is 
most appropriate to conduct CIB and DBS tests at the same test speeds. 
Honda asserted that evaluating DBS performance only at higher test 
speeds may skew performance ratings (similar to what Auto Innovators 
stated) and not accurately convey the real-world safety benefits DBS 
provides at lower test speeds. Since CIB and DBS address different 
safety needs (i.e., the driver is either not responsive, or responsive, 
respectively, to an imminent collision), the automaker indicated that 
it is imperative to ensure ratings reflect the benefits afforded by 
both technologies. Accordingly, Honda, like Auto Innovators, suggested 
that if the Agency moves forward with such an approach, vehicles should 
be awarded credit for lower speed DBS tests as well (even though they 
would only be tested for CIB and not DBS) if the vehicle received 
passing results for the CIB system at the lower test speeds. Honda 
asserted this credit would be appropriate, noting that DBS systems 
should afford equivalent or higher performance than CIB systems when 
tested at the same speeds. Bosch similarly responded that it would be 
appropriate to cover the entire speed range by performing one test per 
scenario and incrementing speeds for each separate scenario by 10 kph 
(6.2 mph) if NHTSA decided to continue to perform separate DBS 
assessments and if there are benefits to increasing both CIB and DBS 
test speeds. CAS also noted that if the Agency imposed higher test 
speeds for LVD CIB assessments, those same test speeds should be used 
to assess DBS. The group stated that DBS activation was highly likely 
for the LVD scenario and all technologies that may contribute to a 
given scenario/crash outcome should be assessed. Likewise, Tesla 
asserted that DBS testing should not be reserved only for higher-speed 
assessments and should be conducted using the same test specifications 
(speed, headway, and POV deceleration) as the corresponding CIB tests.
    Advocates encouraged NHTSA to select the appropriate number of 
tests and test speeds to ensure acceptable performance across a range 
of conditions, including those that would be expected during real-world 
driving.

[[Page 95941]]

Response to Comments and Agency Decisions
    NHTSA's decision regarding CIB and DBS testing specifics can be 
found in the following sections as well as in Tables 12 and 13.
CIB Test Speeds for the LVS Test Scenario
    NHTSA will proceed with assessing CIB performance in NCAP's LVS 
scenario using the proposed SV test speeds and increments. The Agency 
will initiate the LVS test series at the lowest vehicle test speed, 40 
kph (24.9 mph), and test speeds will increase in increments of 10 kph 
(6.2 mph) as each test condition's criteria are met (i.e., no SV-to-POV 
contact is observed), up to and including the 80 kph (49.7 mph) test 
condition.
    Although several commenters, including Advocates, recommended that 
the Agency set the minimum LVS test speed to 10 kph (6.2 mph) to 
harmonize with Euro NCAP, the Agency asserts a 40 kph (24.9 mph) 
minimum LVS test speed is appropriate for NCAP testing. As noted in 
Auto Innovators' comments to the March 2022 RFC notice, Volpe's review 
of 2011-2015 crash data sets showed that, for rear-end crashes, only 2 
percent of fatalities and 6 percent of injuries occurred on roadways 
with posted speed limits of 40.2 kph (25 mph) or 
less.101 102 It is most appropriate, at this time, to 
allocate resources for the flagship consumer information program to 
performing tests representing rear-end crashes that are more likely to 
induce injuries or fatalities instead of those that are more likely to 
cause only property damage.
---------------------------------------------------------------------------

    \101\ Swanson, E., Foderaro, F., Yanagisawa, M., Najm, W.G., & 
Azeredo, P. (2019, August), Statistics of light-vehicle pre-crash 
scenarios based on 2011-2015 national crash data (Report No. DOT HS 
812 745), Washington, DC: National Highway Traffic Safety 
Administration.
    \102\ Data provided is from all rear-end FARS and GES crashes, 
including cases where posted speed limit was unknown.
---------------------------------------------------------------------------

    NHTSA has chosen to set the uppermost SV test speed for CIB LVS 
testing at 80 kph (49.7 mph). A few commenters, such as GM, requested 
that the Agency not make any changes to the current AEB test 
conditions, including the test speeds, stating that the current 
conditions already provide significant real-world safety benefits. 
However, most commenters supported NHTSA's proposal to increase test 
speeds, including for the LVS test scenario, and several commenters 
even suggested adopting higher test speeds, with recommended maximums 
ranging from 88.5 to 104.6 kph (55 to 65 mph). The Agency notes that 
its recent research testing showed CIB tests up to 80 kph (49.7 mph) 
are practicable; however, there is a particular need for improvement in 
CIB performance at vehicle test speeds above 60 kph (37.3 mph). In 
NHTSA's model year 2021-2022 CIB LVS research test series, out of 12 
test vehicles, only three achieved full avoidance at 70 kph (43.5 mph) 
and two achieved full avoidance at 80 kph (49.7 mph). Given these 
results, establishing a maximum test speed of 80 kph (49.7 mph) for 
NHTSA's CIB LVS testing is currently appropriate. Further, as NHTSA 
recognized in its 2022 RFC notice, by adopting a maximum LVS test speed 
of 80 kph (49.7 mph), the Agency will harmonize with Euro NCAP's upper 
test speed limit for its CCRs scenario, which is analogous to NHTSA's 
LVS test scenario. Ensuring robust AEB system performance at 80 kph 
(49.7 mph) also allows the Agency to better target the high severity, 
high-speed crash problem identified in Volpe's real-world data 
analysis, further mitigating serious injuries and fatalities. For 
future iterations of the testing program, the Agency may choose to 
increase this upper test speed, as several commenters suggested, based 
on further real-world data collection and analysis, future research, 
the assurance of test practicability, and other factors.
    As vehicles meet the criteria (i.e., no SV-to-POV contact is 
observed) for passing each LVS test condition, SV test speeds will 
increase in 10 kph (6.2 mph) increments. Thus, LVS tests may be 
conducted for SV test speeds of 40 kph, 50 kph, 60 kph, 70 kph, and 80 
kph (24.9 mph, 31.1 mph, 37.3 mph, 43.5 mph, and 49.7 mph), 
respectively, depending on the vehicle's performance at each speed. 
Should a test failure occur at any of these speeds, defined as SV-to-
POV contact during the single trial performed at that respective speed, 
the test laboratory will discontinue the LVS test series. By using 10 
kph (6.2 mph) increments, the Agency can minimize potential damage to 
the test vehicle and vehicle test device as test speeds and potential 
impact energy increase.
CIB Test Speeds for the LVM Test Scenario
    NHTSA will adopt the same SV test speeds for LVM testing that it is 
adopting for LVS testing: a minimum speed of 40 kph (24.9 mph) with 
speed increases in increments of 10 kph (6.2 mph), up to and including 
80 kph (49.7 mph), as test vehicles meet criteria (i.e., no contact) 
for passing each LVM condition. This approach results in potential SV 
test speeds of 40 kph, 50 kph, 60 kph, 70 kph, and 80 kph (24.9 mph, 
31.1 mph, 37.3 mph, 43.5 mph, and 49.7 mph), respectively, depending on 
vehicle performance at each speed. For the lead vehicle, the POV speed 
will be 20 kph (12.4 mph) regardless of SV test speed.
    NHTSA's rationale for adopting the LVS minimum and maximum SV test 
speeds and speed increments also pertains to LVM testing. The Agency 
asserts the selected speeds relate well to the rear-end crash problem 
and should thus improve real-world safety. Also, LVM testing at the 
selected speeds is possible. Not only are the SV speeds selected 
already assessed by Euro NCAP in its CCRm test,\103\ but also, during 
model year 2021-2022 research testing, NHTSA found that vehicle models 
performed more favorably throughout the battery of test speeds in its 
CIB LVM test series than in its LVS test series. Only one vehicle did 
not achieve full avoidance in the 70 kph (43.5 mph) condition, and an 
additional three did not fully avoid the POV in the 80 kph (49.7 mph) 
condition. The rest of the vehicles were able to fully avoid SV-to-POV 
impact in every CIB LVM test condition. Because the lead vehicle is 
moving in LVM tests, the SV's speed relative to the POV is lower than 
in the LVS scenario for any given test speed. Further, the current NCAP 
protocol specifies similar minimum SV speeds and slightly lower maximum 
SV speeds (40.2 kph (25 mph) and 72.4 kph (45 mph)), so it is possible 
manufacturers have already designed their vehicles' CIB systems to 
mitigate such crashes.
---------------------------------------------------------------------------

    \103\ European New Car Assessment Programme (Euro NCAP) 
(December 2023), Test Protocol--AEB Car-to-Car systems, Version 4.3. 
See section 8.2.2.2.
---------------------------------------------------------------------------

    Adopting a POV speed of 20 kph (12.4 mph) is appropriate for the 
LVM tests. As noted in the March 2022 RFC notice, Euro NCAP's CCRm 
protocol specifies this POV speed, offering another opportunity for 
NCAP to harmonize with other consumer information programs.
    Although Subaru recommended that the Agency adopt a speed increment 
of 20 kph (12.4 mph) in lieu of 10 kph (6.2 mph) for NCAP's LVM 
testing, explaining that this speed increment would be ``adequate for 
system evaluation,'' conducting an additional two test runs at 50 and 
70 kph (31.1 and 43.5 mph) in addition to 40, 60, and 80 kph (24.9, 
37.3, and 49.7 mph) should not add significantly to the test burden. 
Therefore, the Agency does not see a reason to deviate for the LVM test 
scenario from the 10 kph (6.2 mph) speed increment adopted for the 
other AEB test scenarios.

[[Page 95942]]

CIB Test Speeds for the LVD Test Scenario
    For the LVD CIB test scenario, the Agency will conduct tests using 
two SV/POV test speeds only: 50 kph (31.1 mph) and 80 kph (49.7 mph). 
NHTSA chose these speeds for several reasons. First, Euro NCAP 
specifies a 50 kph (31.1 mph) test speed for its CCRb scenario,\104\ 
and adopting this speed allows the Agency to harmonize its testing in 
this regard. Adopting an 80 kph (49.7 mph) uppermost test speed also 
aligns with the highest speed NHTSA is adopting for NCAP's LVM and LVS 
test scenarios.
---------------------------------------------------------------------------

    \104\ European New Car Assessment Programme (Euro NCAP) 
(December 2023), Test Protocol--AEB Car-to-Car systems, Version 4.3. 
See section 8.2.2.3.
---------------------------------------------------------------------------

    Second, in NHTSA's model year 2021-2022 research testing series, 
vehicles performed reasonably well for the 50 kph (31.1 mph) LVD test 
conditions. Half of the tested models met all the requirements for 
every test condition (i.e., varying headways and POV decelerations). 
However, the 80 kph (49.7 mph) LVD test conditions proved more 
difficult, with SV-to-POV contact observed in most vehicle trials. 
Varying responses in vehicle braking systems and/or AEB algorithms may 
have contributed to the performance differences seen at 50 kph (31.1 
mph) versus 80 kph (49.7 mph). However, one vehicle was able to pass 
all test criteria for the 80 kph (49.7 mph) LVD test condition, thus 
proving that robust AEB performance at this higher test speed is 
feasible. This vehicle was a popular model with a high sales volume, 
and the Agency has not observed an increase in reports of false 
activations in the field. Thus, it is NHTSA's view that Auto 
Innovators' concern that encouraging swift innovation will result in 
many false positive activations is unfounded, at least up to the 
maximum speed the Agency has chosen to adopt at this time.
    Third, NHTSA has confirmed that its initial concern (which was also 
expressed by Toyota) regarding safety considerations and equipment 
limitations when running higher-speed LVD tests was unwarranted for 
speeds up to 80 kph (49.7 mph). The Agency's recent research for model 
year 2021-2022 vehicles showed that it is feasible to conduct CIB LVD 
testing at 80 kph (49.7 mph) safely. Further, neither test track 
limitations nor achieving the higher GVT speeds were found to be 
problematic during this testing.
    Finally, as mentioned previously, NHTSA notes that real-world 
fatality and injury data highlights a safety need for testing at higher 
speeds, further suggesting that adopting an 80 kph (49.7 mph) upper 
test speed for the LVD test scenario is warranted. While Euro NCAP's 
CCRb test scenario specifies a single test speed of 50 kph (31.1 mph), 
and Intel requested that NHTSA adopt only this speed for the LVD 
scenario, adopting 80 kph (49.7 mph) in addition to 50 kph (31.1 mph) 
is appropriate. This decision also aligns with the recommendation made 
by other commenters, including Tesla and Subaru.
    NHTSA acknowledges Subaru's recommendation that the Agency should 
perform an additional test at 70 kph (43.5 mph) if the SV contacted the 
POV during the 80 kph (49.7 mph) test to identify the vehicle's CIB 
performance threshold. Other commenters stated that NHTSA should test a 
range of speeds for the LVD tests, like the range being adopted for LVM 
and LVS scenarios. However, the initial speed conditions for the LVD 
scenario are not as critical to the outcome as other test parameters, 
such as headway and POV deceleration, since the SV and POV speeds are 
initially the same. Therefore, the Agency has decided to use two 
discrete speeds to evaluate LVD performance instead of speed increments 
but, as detailed in the next sub-section, will vary the headway and POV 
deceleration magnitude assessed for each speed. The use of two speeds 
is expected to ensure system robustness while limiting test burden.
    NHTSA also acknowledges Toyota's comments that, in some high-speed 
cases, steering away from the impending crash may be preferable to 
remaining in the same travel lane and fully braking, since the time 
required to steer away would be less than the time required to fully 
stop.\105\ That said, the timing necessary to steer away from a crash 
rather than brake is not the only factor that should be considered; 
vehicle dynamics, traffic conditions, and other traffic participants 
all influence the possibility and advisability of a steering avoidance 
maneuver. Steering to avoid a crash with a lead vehicle could cause the 
subject vehicle to either depart the road, collide with a vehicle in 
the adjacent lane, or on an undivided two-lane road, causing a head-on 
frontal crash. As such, the situations in which an evasive steering 
maneuver to avoid a crash would likely be the preferable response would 
be under limited circumstances, since there must be sufficient space in 
a lane or on the shoulder adjacent to the subject vehicle's lane that 
the subject vehicle may move to, and the driver must have the ability 
to safely maneuver a vehicle at such a high speed. Further, it is 
unreasonable to assume that a driver who is inattentive until moments 
before a crash will reengage and be able to perform a safe steering 
maneuver that would not jeopardize the safety of others in the 
surrounding area or themselves.
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    \105\ The Agency additionally notes that Euro NCAP awards points 
for vehicles equipped with Emergency Steering Support (ESS) systems 
that assist a driver in safely maneuvering around an obstacle in 
select scenarios. See TB037, https://cdn.euroncap.com/media/68587/tb-037-ess-assessment-v10.pdf.
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    Research also shows drivers are not prone to initiate steering 
alone to avoid a surprise obstacle in front of them in the roadway in 
an emergency situation.\106\ Instead, they either brake, or brake and 
steer. When drivers were presented with a surprise obstacle catapulted 
from the side (which typically would invoke a steering response) at a 
TTC of 1.5 seconds, with the adjacent lane free of obstacles such that 
the drivers had the opportunity to avoid a collision by steering alone, 
43 percent of research participants attempted to avoid the obstacle by 
braking alone. The other 57 percent of participants tried to avoid a 
collision by braking and steering, while no participant tried to avoid 
contact by steering alone. Only as the TTC increased (i.e., above 2.0 
seconds) did drivers feel comfortable attempting to avoid the obstacle 
by steering alone. At a TTC of 2.0 seconds, 46 percent of participants 
tried to avoid by braking alone, 38 percent tried to avoid by braking 
and steering, and 15 percent tried to avoid by steering alone, while at 
a TTC of 2.5 seconds, 72 percent of participants tried to avoid by 
braking only, 14 percent tried to avoid by braking and steering, and 14 
percent tried to avoid by steering alone. These findings further 
reinforce the Agency's assertion that braking in lane is appropriate at 
the speeds NCAP will test.
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    \106\ Emergency Steer and Brake Assist--A Systematic Approach 
for System Integration of Two Complementary Driver Assistance 
Systems (Eckert, Continental AG, Paper Number 11-0111), https://www-hesv.nhtsa.dot.gov/Proceedings/22/files/22ESV-000111.pdf.
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    The Agency also notes that in its data analysis, for those rear-end 
crashes where the driver's avoidance maneuver was known, Volpe found 
the driver made no attempt to avoid the crash for 75 percent of crashes 
involving fatalities and 48 percent of crashes involving 
injuries.107 108 Therefore, initiating

[[Page 95943]]

steering (which would require driver engagement) during an AEB test 
would not address this large portion of crashes resulting in injuries 
and fatalities. Given the findings from these studies, the Agency's 
current AEB test requirement for braking in the absence of steering is 
appropriate. However, this is not to say that steering must be 
suppressed in crash-imminent situations.
---------------------------------------------------------------------------

    \107\ Swanson, E., Foderaro, F., Yanagisawa, M., Najm, W.G., & 
Azeredo, P. (2019, August), Statistics of light-vehicle pre-crash 
scenarios based on 2011-2015 national crash data (Report No. DOT HS 
812 745), Washington, DC: National Highway Traffic Safety 
Administration.
    \108\ The SV driver's avoidance maneuver was unknown for 25 
percent of fatal rear-end crashes and 54 percent of rear-end crashes 
with police-reported injuries.
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CIB Headway for the LVD Test Scenario
    NHTSA plans to adopt the 12 m (39.4 ft.) and 40 m (131.2 ft.) 
headway conditions proposed for both the 50 kph (31.1 mph) and 80 kph 
(49.7 mph) LVD CIB tests. The Agency's model year 2021-2022 testing 
demonstrated that no contact performance is practicable for both 
headways, even at the highest test speed (i.e., 80 kph (49.7 mph)) and 
most stringent POV deceleration proposed (i.e., 0.5g). One of the 
twelve test vehicles was able to achieve no contact performance at 80 
kph (49.7 mph) with an initial headway of 12 m and lead vehicle 
deceleration of 0.5g. This same vehicle, in addition to a second model, 
was also able to meet the test requirements at the same test speed for 
a headway of 40 m and POV deceleration of 0.5g. For an SV test speed of 
50 kph (31.1 mph) and 0.5g POV deceleration, all but one of the twelve 
vehicles tested avoided contact with the POV for the 40 m headway and 
six of the twelve vehicles provided passing performance for the 12 m 
headway.
    NHTSA previously stated that adopting multiple headways in the LVD 
CIB test to assess CIB system performance would unnecessarily increase 
test burden because longer headways should result in less stringent 
test conditions compared to shorter headways. However, the Agency's 
recent model year 2021-2022 research test findings contradicted this 
assertion. Specifically, greater relative speed reduction was not 
always observed for the longer assessed headway (40 m (131.2 ft.)) 
compared to the shorter headway (12 m (39.4 ft.)), as the Agency had 
expected. When assessing vehicles at 50 kph (31.1 mph) with a POV 
deceleration of 0.5g, one vehicle experienced greater relative speed 
reduction during the shorter headway (12 m (39.4 ft.)) test than during 
the longer headway (40 m (131.2 ft.) test. For LVD CIB tests completed 
at 80 kph (49.7 mph) and 0.4g POV deceleration, six vehicle models 
performed better in the shorter headway test compared to the longer 
headway test.\109\ Thus, the Agency now reasons that assessments using 
both headways--the 12 m (39.4 ft.) condition proposed by NHTSA and the 
40 m (131.2 ft.) condition required by Euro NCAP in its CCRb test--are 
necessary for NCAP testing (in addition to the two adopted test speeds) 
to assess CIB performance in the LVD test scenario.
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    \109\ Note that most of the vehicles in this test series did not 
undergo CIB LVD testing at 80 kph (49.7 mph) and 0.5g POV 
deceleration. Thus, 0.4g POV deceleration data was used.
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    The Agency notes that HATCI requested NHTSA increase headways for 
higher-speed testing based on field-representative distances. 
Alternatively, it and other commenters recommended that NHTSA adjust 
headways based on test speed to achieve specific times-to-collision, 
suggesting these would be more representative of real-world driving. 
Such changes are not necessary, since results from NHTSA's recent 
research demonstrate it is possible to achieve full avoidance across 
both short and long headways, even at the highest speed and highest POV 
deceleration for the CIB LVD tests. Further, while maintaining a 12 m 
(39.4 ft.) headway at an 80 kph (49.7 mph) travelling speed is 
uncomfortably close and more likely to result in a crash imminent 
situation, it is reflective of the real-world driving habits of some 
individuals. In such situations, it will be difficult, even for an 
attentive driver, to react quickly enough to avoid a crash, especially 
with a lead vehicle braking above 0.3g. As such, it is imperative to 
ensure vehicles respond quickly and appropriately in such instances. 
Performing CIB tests in NCAP with an 80 kph (49.7 mph) test speed and 
12 m (39.4 ft.) headway can provide this assurance.
    Based on the results of NHTSA's recent model year 2021-2022 
research testing, and in an effort to harmonize test procedures as much 
as possible with other consumer information programs per the BIL 
mandate, NHTSA will conduct tests using both 12 m (39.4 ft.) and 40 m 
(131.2 ft.) headways for both test speeds selected for CIB LVD testing.
CIB POV Deceleration Magnitude for the LVD Test Scenario
    With respect to NHTSA's proposal to increase the POV deceleration 
magnitude currently specified in NCAP's CIB LVD test procedure from 
0.3g to 0.5g or 0.6g for this upgrade of NCAP, the Agency has decided 
to retain a 0.3g POV deceleration in its CIB LVD tests and adopt a 0.5g 
POV deceleration specification.\110\
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    \110\ The Agency notes that testing with a 12 m (39.4 ft.) 
headway and a POV deceleration of 0.5g roughly corresponds to the 
deceleration necessary to comply with the minimum stopping distance 
required in FMVSS No. 135, ``Light vehicle brake systems.''
---------------------------------------------------------------------------

    While NHTSA sought comments on adopting a 0.6g POV deceleration for 
LVD testing and received some supportive feedback regarding this idea 
due in part to Euro NCAP's use of a similar test specification (6 m/
s\2\), the Agency reasons that adopting a maximum 0.6g POV deceleration 
is not appropriate at this time. Although harmonization is generally 
desired, Euro NCAP requires only a 50 kph (31.1 mph) test speed for its 
CCRb test and provides partial credit for speed reduction, while NHTSA 
has also adopted an 80 kph (49.7 mph) test speed and is moving forward 
with a no contact passing criterion for its CIB testing (as discussed 
later). Additionally, as mentioned in its March 2022 RFC notice, NHTSA 
observed excessive wear on the GVT's tires (i.e., flat-stopping due to 
wheel lockup) while conducting research testing during braking 
maneuvers where the POV deceleration was near 0.6g, and found it was 
more difficult to achieve and accurately control deceleration within 
the prescribed tolerances when braking maneuvers were performed with 
decelerations higher than 0.5g, even with extensive tuning efforts. 
Commenters also suggested that a 0.5g deceleration was less likely than 
a 0.6g deceleration to introduce repeatability issues or cause damage 
to test equipment. To limit potential testing challenges, NHTSA is 
adopting a 0.5g maximum POV deceleration for NCAP's updated LVD test 
requirements at this time but may consider incorporating a 0.6g 
deceleration as part of future program updates if testing concerns can 
be alleviated.
    The Agency notes that many commenters asserted a 0.5g deceleration 
was representative of real-world driving. NHTSA's previous research 
suggests that drivers decelerate up to approximately 0.3g in a non-
emergency situation and up to approximately 0.5g when encountering an 
unexpected obstacle.\111\ Additionally, past NHTSA research analysis of 
rear-end crash event data recorder data showed that drivers applied the 
brakes at approximately 0.4g

[[Page 95944]]

in rear-end crash scenarios.\112\ Therefore, a POV deceleration of 0.5g 
seems reasonable to adopt (i.e., compared to 0.6g) when real-world 
driving data are considered.
---------------------------------------------------------------------------

    \111\ Fitch, G.M., Blanco, M., Morgan, J.F., Rice, J.C., 
Wharton, A., Wierwille, W.W., & Hanowski, R.J. (2010, April) Human 
Performance Evaluation of Light Vehicle Brake Assist Systems: Final 
Report (Report No. DOT HS 811 251) Washington, DC: National Highway 
Traffic Safety Administration, p. 13 and p. 101.
    \112\ Automatic Emergency Braking System (AEB) Research Report, 
NHTSA, August 2014, pg. 47. https://www.regulations.gov/document/NHTSA-2012-0057-0037.
---------------------------------------------------------------------------

    Given these data, there is also reason to retain the 0.3g POV 
deceleration currently specified in the Agency's CIB test procedure. 
Adopting this lower deceleration magnitude in addition to 0.5g will 
ensure vehicles continue to perform as expected in situations where the 
lead vehicle decelerates at a more moderate rate. The Agency reasons 
that CIB systems should function whether the lead vehicle is engaged in 
an emergency maneuver or not. AEB systems that perform well in a test 
with higher lead vehicle deceleration may not necessarily offer 
comparable or better performance in tests with lower lead vehicle 
decelerations. The Agency also notes Euro NCAP takes a similar approach 
to testing in its CCRb scenario. In addition to the previously 
mentioned 6 m/s\2\ (19.7 ft./s\2\) deceleration, Euro NCAP prescribes a 
lower POV deceleration of 2 m/s\2\ (6.6 ft./s\2\). Tesla and Advocates 
also agreed with such a testing approach. By adopting two POV 
deceleration rates for NHTSA's NCAP testing, manufacturers will need to 
demonstrate that their vehicles offer consistent performance by 
effectively recognizing and responding to lead vehicles that are 
braking at various rates.
    While much of the Agency's recent model year 2021-2022 research 
testing was conducted using a 0.4g POV deceleration in addition to a 
0.5g POV deceleration at each headway and test speed, NHTSA is not 
adopting a POV deceleration of 0.4g for its future NCAP testing. At the 
lower test speed of 50 kph (31.1 mph) and longer headway of 40 m (39.4 
ft.), all vehicles achieved full avoidance when the POV decelerated at 
0.4g and all but one vehicle met the no-contact requirements at a POV 
deceleration of 0.5g. Reducing the headway to 12 m (39.4 ft.) made this 
test condition more challenging, with half the vehicles tested 
achieving full avoidance when subjected to POV decelerations of 0.4g 
and 0.5g.\113\ As noted earlier in this notice, higher-speed LVD 
testing (i.e., 80 kph (49.7 mph)) was more rigorous, and few vehicles 
offered full avoidance for either headway. However, for the 80 kph 
(49.7 mph) conditions, vehicles that achieved full avoidance in a given 
0.4g POV deceleration test condition also achieved full avoidance when 
subjected to the same condition but with a POV deceleration of 0.5g. 
While the Agency has noted (above) that vehicles may not always provide 
comparable or better performance for lower POV decelerations, NHTSA's 
test data shows they often do, thus suggesting it may be appropriate 
for NCAP, in consideration of limiting test burden, to adopt one of 
these decelerations (i.e., 0.4 or 0.5g) without sacrificing the 
program's efforts to ensure robust CIB system performance. This 
decision seems especially reasonable since NHTSA has decided to retain 
a 0.3g POV deceleration while adding a 0.5g deceleration.
---------------------------------------------------------------------------

    \113\ If a vehicle did not achieve full avoidance during the 
0.4g POV deceleration test condition, the 0.5g POV deceleration test 
condition was not assessed.
---------------------------------------------------------------------------

    For the LVD CIB scenario, NHTSA will impose a similar testing 
assessment process to that adopted for the LVS and LVM CIB scenarios. 
The Agency will perform the LVD CIB test conditions in a manner 
consistent with increasing stringency. The first LVD trial will be 
performed at the minimum test speed (50 kph (31.1 mph)), maximum 
headway (40 m (131.2 ft.)), and minimum deceleration (0.3g). If the 
initial trial run is valid (i.e., all test specifications and 
tolerances are satisfied) and the SV does not contact the POV, the 
Agency will proceed with conducting the next trial run at the same test 
speed (50 kph (31.1 mph)) and deceleration (0.3g) but will adjust the 
headway to the minimum specified distance, 12 m (39.4 ft.). If the 
vehicle does not contact the POV for this test condition and the trial 
run is determined to be valid, NHTSA will then increment the test speed 
to the maximum LVD test speed, 80 kph (49.7 mph), and perform one trial 
run at the maximum headway (40 m (131.2 ft.)) and minimum deceleration 
(0.3g), followed by one trial run at 80 kph (49.7 mph), minimum headway 
(12 m (39.4 ft.)), and minimum deceleration (0.3g). If no vehicle-to-
POV contact is observed and all 80 kph (49.7 mph) trials are considered 
valid, the Agency will repeat the LVD test sequence utilizing a POV 
deceleration of 0.5g. See Table 14 for the sequence of CIB LVD tests.
DBS Testing in NCAP
    After consideration of the most recent research data and comments 
received from the public in response to the March 2022 RFC notice, the 
Agency has decided to retain DBS testing in NCAP.
    For the LVS and LVM scenarios, NHTSA will perform DBS assessments 
at the two highest test speeds adopted for the complementary CIB test 
scenarios--70 kph (43.5 mph) and 80 kph (49.7 mph)--as well as two 
additional speeds, 90 kph (55.9 mph) and 100 kph (62.1 mph). The 
performance criterion for each assessment will be ``no contact,'' and 
the POV speeds adopted for DBS will align with those adopted for CIB 
evaluation (i.e., 0 kph (0 mph) for the LVS scenario and 20 kph (12.4 
mph) for the LVM scenario). For the LVD scenario, the Agency will 
perform DBS assessments in all eight test conditions covered by CIB: 50 
kph (31.1 mph) and 80 kph (49.7 mph), each at 12 m (39.4 ft.) and 40 m 
(131.2 ft.) headways and each with 0.3g and 0.5g POV deceleration. Like 
the LVS and LVM DBS tests, the performance criterion adopted for the 
LVD DBS assessment will be ``no contact.''
    NHTSA notes that commenter suggestions on appropriate DBS test 
speeds varied. Some suggested that the Agency conduct CIB and DBS tests 
at the same speeds or alternate between CIB and DBS testing above 
certain speeds. Others recommended that NHTSA perform CIB tests at 
lower speeds and DBS tests at higher speeds, albeit sometimes with 
slight deviations (e.g., conducting DBS testing at the next highest 
speed once the CIB system fails to provide complete avoidance.) Several 
commenters also stated that NHTSA should conduct AEB assessments, in 
general, at speeds higher than those proposed, citing the need to 
better reflect real-world driving conditions and foster ideal system 
performance. There is merit to these commenters' recommendations for 
NCAP's DBS tests. In its real-world data analysis, Volpe found that, 
for rear-end crashes where posted speed was known, over 37 percent of 
fatalities and 21 percent of injuries occurred on roadways having 
posted speeds between 80 kph (49.7 mph) and 100 kph (62.1 
mph).114 115
---------------------------------------------------------------------------

    \114\ Swanson, E., Foderaro, F., Yanagisawa, M., Najm, W.G., & 
Azeredo, P. (2019, August), Statistics of light-vehicle pre-crash 
scenarios based on 2011-2015 national crash data (Report No. DOT HS 
812 745), Washington, DC: National Highway Traffic Safety 
Administration.
    \115\ Posted speed limit was unknown or not reported in 2 
percent of fatal rear-end crashes and 11 percent of rear-end crashes 
with injuries.
---------------------------------------------------------------------------

    By adopting two additional higher test speeds for NCAP's LVS and 
LVM test scenarios (i.e., 90 kph (55.9 mph) and 100 kph (62.1 mph)) in 
addition to those proposed (i.e., 70 kph (43.5 mph) and 80 kph (49.7 
mph)), the program's DBS tests would represent the posted speeds at 
which more than 65 percent of fatalities and 91 percent of injuries 
occurring in rear-end crashes.\116\

[[Page 95945]]

NHTSA's testing has shown such test speeds to be practicable with 
respect to both testing feasibility and current AEB system 
capabilities. In its model year 2021-2022 research testing, one vehicle 
was able to provide complete crash avoidance up to 100 kph (62.1 mph) 
for all LVM and LVS test conditions.\117\ This is likely because a 
speed differential of 80 kph (49.7 mph) in the Agency's LVS CIB test, 
where no manual braking is imparted, affords similar stringency to the 
Agency's LVS DBS test scenario for a test speed of 100 kph (62.1 mph), 
where manual braking at a constant average deceleration of 0.4g is 
required. The Agency also maintains that a 100 kph (62.1 mph) LVS DBS 
test would require braking that is no harsher than that currently 
demonstrated by vehicles compliant with FMVSS No. 135, ``Light vehicle 
brake systems.'' In addition, a maximum subject vehicle test speed of 
100 kph (62.1 mph) in the Agency's DBS LVM test affords similar 
stringency as a test speed of 80 kph (49.7 mph) in its DBS LVS test 
since the POV speed in the LVM test is 20 kph (12.4 mph), and thus, the 
relative speed between the subject vehicle and POV is 80 kph (49.7 
mph).
---------------------------------------------------------------------------

    \116\ Swanson, E., Foderaro, F., Yanagisawa, M., Najm, W.G., & 
Azeredo, P. (2019, August), Statistics of light-vehicle pre-crash 
scenarios based on 2011-2015 national crash data (Report No. DOT HS 
812 745), Washington, DC: National Highway Traffic Safety 
Administration.
    \117\ This same vehicle, when tested for the LVD scenario with 
the more stringent headway and POV deceleration (i.e., a 12 m 
headway and 0.5g POV deceleration), was also able to avoid collision 
when tested at 50 kph (31.1 mph) and 80 kph (49.7 mph).
---------------------------------------------------------------------------

    While NHTSA is adopting a 100 kph (62.1 mph) maximum speed for its 
DBS LVS and LVM assessments, NHTSA's proposed maximum speed of 80 kph 
is appropriate for its DBS LVD assessment. As mentioned for the CIB LVD 
test, there was some concern regarding the ability to perform LVD 
testing reliably at 80 kph (49.7 mph). While research data has shown 
that testing at this speed is feasible and practicable, LVD research 
testing has not been conducted at speeds higher than 80 kph (49.7 mph). 
As such, the Agency hesitates to raise the DBS LVD test speeds to match 
those for LVS and LVM. Another concern raised in response to the March 
2022 RFC was related to the LVD scenario and FCW timing for higher test 
speeds, with Toyota and Intel both noting there may not be sufficient 
time to: (1) issue the FCW, (2) wait for the prescribed amount of time 
between FCW and brake activation (i.e., 1.0 second, as proposed), and 
(3) initiate braking during an LVD assessment where POV deceleration is 
0.5g and headway is 12 m (39.4 ft.). In fact, Toyota stipulated that 
the POV may not have even begun decelerating at the time at which the 
FCW would need to be issued. However, during its research testing, 
NHTSA found many vehicle models are currently available to meet this 
criterion.\118\ In the 12 m (39.4 ft.) headway LVD tests with 0.5g POV 
deceleration, for a 50 kph (31.1 mph) test speed, eight vehicle models 
were able to fully avoid the POV. For the 80 kph (49.7 mph) test speed, 
four were able to achieve full avoidance.\119\ These results confirm 
that the requirements adopted for the LVD test conditions are feasible 
for current DBS systems. The Agency's decision (discussed later) to 
explicitly allow automatic braking resulting from CIB activation after 
issuance of the FCW but prior to manual brake application during DBS 
testing is also an important consideration, as it ensures the SV is 
provided with the best overall opportunity to avoid the POV regardless 
of whether a manual brake application is being used.
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    \118\ The time between FCW onset and braking initiation for this 
testing was set at 1.0 second, which is the timing being adopted in 
this final notice (see later section).
    \119\ https://www.regulations.gov/document/NHTSA-2023-0021-0005.
---------------------------------------------------------------------------

    Although there was overall support for retaining DBS testing in 
NCAP, NHTSA also recognizes that a few commenters suggested that 
continued testing for this technology was unnecessary. For example, 
Subaru stated that NHTSA remove DBS assessments from NCAP because DBS 
systems have a record of good performance. The automaker reasoned that 
mature ADAS technologies with high adoption rates could be removed and 
replaced with other emerging technologies. In general, NHTSA agrees 
with this approach, but it does not agree there are no further gains to 
be made regarding DBS performance. Model year 2021-2022 research 
testing showed that, at test speeds greater than 80 kph (49.7 mph), 
vehicle models offered a range of DBS performance in the LVM test. Of 
the 12 models, four did not offer full avoidance at 90 kph (55.9 mph) 
and an additional five did not offer full avoidance at 100 kph (62.1 
mph). For the DBS LVS condition, five did not offer full avoidance at 
70 kph (43.5 mph), three did not offer full avoidance at 80 kph (49.7 
mph), two did not offer full avoidance at 90 kph (55.9 mph), and 
another one did not offer full avoidance at 100 kph (62.1 mph). 
Further, one vehicle was able to fully avoid contact through 80 kph 
(49.7 mph) in the CIB LVS tests but did not avoid contact in the 90 kph 
(55.9 mph) DBS LVS test, which would be expected to be less challenging 
based on the additional manual braking imparted by the driver.
    DBS LVD assessments at 80 kph (49.7 mph) also demonstrated room for 
improvement in the same study. When the POV deceleration was 0.4g, only 
five of the total 12 vehicles tested were able to fully avoid the POV 
for the 40 m (131.2 ft.) headway test condition, while six of the total 
12 were able to fully avoid the POV in the 12 m (39.4 ft.) headway test 
condition. When the POV deceleration was increased to 0.5g, only three 
of five vehicle models tested for the 80 kph (49.7 mph), 40 m (131.2 
ft.) headway test condition provided full avoidance and four of the six 
vehicle models achieved this performance for the 12 m (39.4 ft.) 
headway test condition. Several commenters also stated that continuing 
to perform DBS testing for each of the test conditions adopted for CIB 
would be redundant and only serve to increase test burden. The Agency's 
decision to adopt additional higher test speeds than those adopted for 
CIB (i.e., 90 kph (55.9 mph) and 100 kph (62.1 mph)) for its LVS and 
LVM tests, in addition to a ``no contact'' performance criterion, 
effectively ensures that the majority of NCAP's DBS tests will be as 
stringent as the program's CIB tests. Thus, it is not necessary at this 
time to require a higher level of stringency in NCAP's DBS tests 
compared to its CIB tests to justify the need to retain DBS testing in 
NCAP. Rather, the Agency agrees with those commenters who suggested 
that DBS testing in NCAP is necessary to ensure that brake pedal 
application does not adversely affect overall AEB functionality or 
suppress CIB operation. If a driver attempts to brake but does so with 
an input that is insufficient to avoid a crash, the vehicle's DBS 
system must support the driver's action and intention to stop the 
vehicle.
    With respect to the assessment approach to be used for NCAP's DBS 
tests, the Agency plans to align its approach for the LVS and LVM DBS 
tests with those finalized for CIB; however, the first and last SV 
speed in the respective test series will be higher. NHTSA will initiate 
the DBS test sequence for each of the LVS and LVM scenarios by 
performing a trial run at the minimum DBS test speed in the sequence 
(i.e., 70 kph (43.5 mph)) and will then incrementally increase the test 
speed by 10 kph (6.2 mph) to assess the next test condition in the 
sequence (i.e., 80 kph (49.7 mph)), as long as the initial trial run is 
valid (i.e., all test specifications and tolerances satisfied) and the 
SV does not contact the POV. This incremental process will continue

[[Page 95946]]

until the maximum test speed of 100 kph (62.1 mph) is assessed.
    For the LVD scenario, NHTSA will impose a DBS testing assessment 
process that is identical to that adopted for the LVD CIB tests. The 
Agency will conduct the first LVD trial at the minimum test speed (50 
kph (31.1 mph)), maximum headway (40 m (131.2 ft.)), and minimum 
deceleration (0.3g). If the initial trial run is valid (i.e., all test 
specifications and tolerances satisfied) and the SV does not contact 
the POV, the next trial run will be conducted at the same test speed 
(50 kph (31.1 mph)) and deceleration (0.3g) but the headway will be 
adjusted to the minimum specified distance, 12 m (39.4 ft.). If the 
vehicle fully avoids contacting the POV for this test condition and the 
trial run is determined to be valid, NHTSA will then increment the test 
speed to the maximum LVD test speed, 80 kph (49.7 mph), and will 
perform one trial run at the maximum headway (40 m (131.2 ft.)) and 
minimum deceleration (0.3g), followed by one trial run at 80 kph (49.7 
mph), minimum headway (12 m (39.4 ft.)), and minimum deceleration 
(0.3g). If no vehicle-to-POV contact is observed and all 80 kph (49.7 
mph) trials are considered valid, the Agency will repeat the LVD DBS 
test sequence utilizing a POV deceleration of 0.5g. See Table 15 for 
the sequence of LVD DBS tests.
    The test conditions, performance criteria, and assessment 
approaches adopted for the LVS, LVM, and LVD DBS test scenarios will 
allow NHTSA to keep test burden to a minimum while confirming 
functionality of DBS systems and ensuring acceptable system performance 
across a range of real-world driving conditions, as Advocates 
requested.
c. Removal of False Positive Assessments
    When the STP test was initially developed, many AEB systems relied 
solely on radar for lead vehicle detection. Today, most vehicles 
utilize a camera-only or fused system that relies on both camera and 
radar. While some radar-only systems have had difficulty classifying 
the STP correctly (i.e., responding to the STP as if it was a vehicle), 
camera-only and fused systems have not exhibited this issue.\120\ Since 
its AEB testing began in NCAP for model year 2017 vehicles, the Agency 
has observed no instances of false positive test failures during CIB 
and DBS NCAP evaluations performed for camera-only and fused AEB 
systems. Since fused camera-radar forward-looking AEB systems are 
becoming more prevalent in the fleet, NHTSA suggested it might be 
appropriate to remove the false positive STP assessments from NCAP's 
AEB (i.e., CIB and DBS) evaluation matrix as part of this NCAP update 
and sought comment in that regard.
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    \120\ This is not to suggest that camera systems are superior to 
radar systems in all tests.
---------------------------------------------------------------------------

Summary of Comments
    Approximately two-thirds of commenters stated that NHTSA could 
remove the STP false positive assessment from NCAP's AEB test matrix. 
The remaining one-third urged the Agency to continue to conduct false 
positive tests.
Remove False Positive Tests
    The following commenters supported removal of the STP false 
positive tests from NCAP's AEB test matrix: Auto Innovators, BMW, 
Bosch, GM, HATCI, Honda, IDIADA, IIHS, Intel, MEMA, Rivian, Toyota, and 
TRC.
    Toyota and HATCI cited improved performance of the latest 
technologies, as demonstrated by NCAP test results, as a reason to 
remove the STP tests. Likewise, TRC mentioned that vehicles may 
occasionally issue an alert when driven over the steel trench plate 
during testing, but they no longer activate AEB.
    Bosch supported removal of the STP assessments from both CIB and 
DBS test procedures due to concerns about the tests' repeatability and 
representation of all real-world driving situations. Along the same 
lines, GM mentioned that the Agency's current STP false positive tests 
address only a very limited number of potential conditions that vehicle 
manufacturers and suppliers must assess as part of their due diligence 
to ensure sensors and systems respond appropriately (i.e., without 
issuing false activations) when driven in a myriad of driving 
environments and conditions. Auto Innovators and BMW agreed that NCAP's 
false positive tests are inadequate to address all potential conditions 
that may incite a false positive event for all AEB systems. As such, 
the commenters asserted that they only serve to unnecessarily increase 
test burden without providing appreciable safety benefit.
    Both GM and Auto Innovators suggested that, in lieu of conducting 
false activation tests, NHTSA should monitor customer complaints about 
frequent false activation events. Both commenters stated that this 
information would be more useful to NHTSA. IIHS also favored such an 
approach to addressing false-positive braking problems. IIHS remarked 
that NHTSA has received customer complaints and opened investigations 
for false positive activations for both radar-only and camera-based AEB 
systems despite currently performing false positive tests and only 
witnessing failures for radar-only systems. Accordingly, the commenter 
concluded that not only are the current tests insufficient to address 
all instances of real-world false activations, but also the Agency 
could use its authority through a recall process to address false 
positive braking problems as they arise. IIHS further mentioned that 
vehicle manufacturers are sufficiently motivated to minimize false-
positive interventions by customer feedback such that false positive 
AEB tests are not necessary.
    Honda and HATCI also stated that the current false positive tests 
no longer address a safety need, particularly since, as Honda added, 
cameras are now a fundamental component of AEB, and their performance 
should continue to improve. Rivian agreed that most vehicles rely on 
fused data (i.e., involving cameras) for FCW and CIB activations but 
also cautioned that ``some manufacturers still rely on radar confidence 
and allow low deceleration radar-only braking.'' As such, the 
manufacturer recommended that the Agency should incorporate scenarios 
that could trigger radar-only braking if it wants to evaluate a 
vehicle's propensity to issue false positive braking. Similarly, FCA 
commented that it would be appropriate for the Agency to remove the STP 
assessment for vehicles equipped with camera-based systems, but NHTSA 
should continue those assessments for vehicles using radar-only 
systems. Intel stated that false positive STP evaluations were now 
``redundant'' for CIB and DBS because the Agency has relaxed the 
allowable deceleration threshold.
Continue To Perform False Positive Tests
    Some commenters (including Adasky, Advocates, CAS, Tesla, Vayyar, 
and ZF Group) stated that NHTSA should continue to conduct false 
positive assessments as part of NCAP's AEB test evaluations.
    Adasky stated that NHTSA should retain the false positive AEB tests 
in NCAP because ``they serve as an indication of the lack of robustness 
of RGB cameras and radars.'' \121\ The supplier also suggested that 
thermal cameras should be encouraged (or required) because they may 
address ``phantom braking'' in real-world cases.

[[Page 95947]]

Adasky noted that thermal cameras offer more robust detection and 
provide the redundancy necessary to overcome RGB camera and radar 
deficiencies. Vayyar explained that removal of false positive 
assessments from NCAP would serve to foster development of ``suboptimal 
technologies'' and drive an increase in real-world false positive 
events. ZF Group reasoned that current and future AEB systems would not 
necessarily be prone to false positive activations, but in the interest 
of safety, the group recommended retaining STP false positive tests in 
NCAP to ensure systems continue to work as expected. Tesla commented 
that false positive activations may become more common as vehicle 
sensing technologies continue to evolve. Accordingly, the automaker 
recommended that NHTSA continue to conduct the current false positive 
STP assessments since they may help provide nuanced distinctions in AEB 
performance among vehicles relying on different sensing technologies in 
the future. Tesla stated this would permit a more comprehensive rating.
---------------------------------------------------------------------------

    \121\ RGB cameras are cameras that can capture light in red, 
green, and blue (hence, RGB) wavelengths.
---------------------------------------------------------------------------

    CAS also stated that NHTSA should continue performing false 
positive STP assessments for AEB. The commenter noted that it would be 
inappropriate to assume system capabilities without test verification, 
especially since false positive activations have been reported for 
production vehicles, and there are many reasons for system failures, 
including supply chain disruptions, design or production issues, and 
manufacturing defects. Advocates opposed eliminating the false positive 
AEB assessments from NCAP until they were adopted into regulations.
Response to Comments and Agency Decisions
    The Agency will retain the STP false positive test in NCAP's AEB 
evaluation matrix. The test scenario will be conducted as part of both 
CIB and DBS system assessments as is done currently in NCAP. However, 
instead of performing the STP test at the currently prescribed test 
speeds, 40.2 and 72.4 kph (25 and 45 mph), the Agency is adopting only 
a test speed of 80 kph (49.7 mph) to mirror the highest test speed 
adopted for CIB testing.
    NHTSA reasons it is no longer necessary to conduct AEB STP tests at 
40.2 kph (25 mph) because the Agency has observed no instances of false 
positive test failures during CIB and DBS NCAP evaluations performed 
since the tests were added to the program for model year 2017 vehicles. 
Requiring only one test speed instead of two for NCAP's CIB and DBS STP 
assessments should also help to offset any added test burden imposed by 
the 90 and 100 kph (55.9 and 62.1 mph) assessments adopted for the 
program's LVM and LVS DBS test scenarios. The slight increase in test 
speed (from 72.4 kph (45 mph), as currently prescribed for NCAP's STP 
tests, to 80 kph (49.7 mph), as adopted) for the higher speed test 
condition is reasonable and justifiable to complement the performance 
requirements adopted for the Agency's other AEB tests. During NHTSA's 
AEB research testing for model year 2021-2022 vehicles, no AEB false 
positives (i.e., unnecessary system activations) were observed for any 
of the twelve vehicles evaluated during the conduct of valid CIB and 
DBS trials for the STP scenario at a test speed of 80 kph (49.7 mph).
    Although some commenters supported removal of the false positive 
tests, others encouraged the Agency to continue to conduct such tests 
in NCAP. Adasky, Tesla, and Vayyar expressed concerns surrounding a 
lack of sensor robustness and an increase in false activations with 
system evolution if NHTSA was to stop performing false positive tests 
in NCAP. While the Agency has not observed false positive test failures 
in CIB or DBS testing since NHTSA added these ADAS technologies to 
NCAP, and similarly did not observe failures in NHTSA's research tests 
for model year 2021-2022 vehicles, it agrees with these commenters that 
it should exercise due diligence given the anticipated system changes 
that will be necessary to ensure current system functionality is 
maintained as sensing technologies evolve and as CIB test speeds 
increase. The Agency remains concerned that false activation events may 
introduce hard braking situations when such actions are not warranted, 
potentially causing rear-end crashes instead of mitigating them. Since 
the consequences of unintended braking can be more significant at 
higher vehicle travel speeds, retaining the highest proposed test speed 
(i.e., 80 kph (49.7 mph) is most appropriate. It is not appropriate at 
this time to adopt a test speed higher than 80 kph (49.7 mph) for the 
program's CIB and DBS STP test assessments, such as the maximum test 
speed adopted for NCAP's DBS tests (i.e., 100 kph (62.1 mph)), since, 
to date, NHTSA has not performed research testing at speeds higher than 
80 kph (49.7 mph) for the STP test.
    Of those commenters that suggested the Agency should remove the 
false positive test conditions from NCAP's AEB test matrix, some, like 
Honda and HATCI, stated the current STP test no longer addresses a 
safety need. However, NHTSA contends that if NCAP's STP test provides 
even limited coverage of real-world false positive conditions, it is 
still beneficial. Along these lines, continuing false positive testing 
in NCAP should lessen Auto Innovators' concern that an increase in 
false positives during real-world driving may discourage AEB use.
    Some commenters asserted that performing false positive tests in 
NCAP should be unnecessary since vehicle manufacturers have an 
incentive to maintain high customer satisfaction; therefore, they will 
design AEB systems to thoroughly address the potential for unwarranted 
braking in real-world driving scenarios. GM asserted that it is the 
vehicle manufacturers' responsibility to ensure systems respond 
appropriately. NHTSA agrees with these commenters in theory and expects 
vehicle manufacturers to design AEB systems to thoroughly address the 
potential for false activations in a myriad of possible real-world 
situations so that vehicles do not pose an unreasonable risk to safety. 
However, the Agency also recognizes that it has received customer 
complaints and opened investigations for false positive activations for 
AEB systems. This suggests that the motivation of positive consumer 
feedback and accountability alone may be insufficient to fully 
eliminate false positive activations. Therefore, it is appropriate to 
retain false positive testing in NCAP's AEB test matrix. The Agency 
maintains this position while acknowledging that current false positive 
tests are neither comprehensive nor sufficient to eliminate 
susceptibility to all false activations. The false activation tests 
serve to provide a baseline for system functionality and to establish a 
minimum expected performance level.
    To address real-world conditions not covered by NCAP's false 
positive test, NHTSA will continue to monitor customer complaints to 
look for reports of frequent false activations as part of its 
oversight. The Agency will conduct investigations, as necessary, to 
determine whether vehicles experiencing excessive false positive 
activations have a safety-related defect and thus pose an unreasonable 
risk to safety. The Agency will continue to handle such cases 
appropriately as they arise. NHTSA also plans to amend or supplement 
the STP test with other false positive activation tests or criteria as 
needed based on real-world data.
Peak Additional Deceleration in DBS False Positive Test
    Currently, in NCAP's STP DBS test, a vehicle's DBS system must not 
engage the brakes to create a peak deceleration

[[Page 95948]]

that is greater than 1.5 times the average of the peak decelerations 
imparted by manual brake application during ``baseline'' tests, which 
are conducted to simulate the magnitude of brake application needed to 
produce 0.4g deceleration using the vehicle's foundation brakes. For 
the Agency's future DBS STP tests, the DBS system must not engage the 
brakes to create a peak deceleration of more than 0.25g additional 
deceleration beyond the average of the peak decelerations recorded 
during the DBS STP ``baseline'' runs. NHTSA is making this change 
because the lower braking threshold, which equates to a maximum 
combined braking level of 0.65g (i.e., combining the 0.4g from the 
foundation's brakes with a possible 0.25g additional deceleration), is 
more appropriate for the false positive test, which offers no real 
crash threat.
    The Agency will also make a similar change for its CIB false 
positive test. Instead of stipulating that a vehicle cannot impart 
braking that exceeds 0.5g in NCAP's CIB STP test, NHTSA is amending the 
criterion to reflect a maximum peak braking of 0.25g. Effectively, the 
vehicle's CIB system must not engage the brakes to create a peak 
deceleration of more than 0.25g during the CIB STP test.
    In imposing these modified requirements, a mild DBS intervention, 
such as that stemming from a haptic brake pulse, is deemed acceptable, 
but one where the vehicle thinks it must respond to the STP as if it 
was a real vehicle is not.
Brake Pedal Application Rate in DBS False Positive Test
    Since the Agency has decided to retain the false positive test 
scenarios for its AEB tests, it plans to retain the current brake pedal 
application rate of 254  25.4 mm/s (10  1 in./
s) for the DBS test, as discussed in the March 2022 RFC notice.
    In response to NHTSA's December 2015 RFC notice, BMW had suggested 
that the Agency should allow manufacturers to specify a brake pedal 
application rate limit up to 400 mm/s (16 in./s) for the false positive 
DBS test scenario to harmonize with Euro NCAP requirements. BMW 
asserted that limiting the rate to a lower threshold could increase a 
DBS system's sensitivity and thereby increase the likelihood of 
additional false activation events in the real world.
    As the Agency mentioned in its RFC notice, the current application 
rate value is not only well within the brake application rate range of 
200 to 400 mm/s (8 to 16 in./s) specified by Euro NCAP,\122\ but also 
has been shown to provide the input characteristics needed to satisfy 
DBS activation thresholds during NHTSA NCAP testing. To reduce the 
potential for an unintended intervention, activation of conventional 
brake assist systems typically requires higher brake pedal application 
rates than those required for DBS. This is because conventional brake 
assist systems assume that if the driver applies the brakes quickly 
(i.e., with a brake pedal velocity profile used by drivers in an 
emergency/panic situation), supplemental braking is appropriate, 
whereas DBS systems consider data from forward-looking sensors and how 
the driver is applying the brakes. The additional data used by DBS 
allows the brake pedal velocity threshold to be lower than that of 
conventional brake assist systems. Thus, retaining the brake 
application rate of 254  25.4 mm/s (10  1 in./
s) in the DBS system performance test enables NHTSA to focus on 
evaluating DBS system performance instead of conventional brake 
technology.
---------------------------------------------------------------------------

    \122\ 80 FR 68608 (Nov. 5, 2015).
---------------------------------------------------------------------------

d. No Contact Versus Speed Reduction Performance Criterion
    In its March 2022 RFC notice, NHTSA proposed to adopt a performance 
criterion of ``no contact'' for both CIB and DBS tests. Although 
NHTSA's DBS test procedure currently specifies ``no contact'' as the 
performance criterion for all DBS test conditions, the Agency's CIB 
test procedure specifies speed reduction as the passing requirement for 
all but one CIB test condition.\123\ Under the Agency's proposal, the 
SV would have to avoid contacting the POV test device to pass CIB and 
DBS test trials. NHTSA reasoned that this approach would limit damage 
to the SV and POV test device during testing, thus maintaining test 
repeatability and vehicle test device usability. However, as 
alternatives to this proposal, NHTSA also asked if it would be more 
appropriate to require minimum speed reductions or specify a maximum 
allowable SV-to-POV impact speed for any or all of the proposed AEB 
test conditions (i.e., test scenario and test speed combinations).
---------------------------------------------------------------------------

    \123\ A performance criterion of ``no contact'' is currently 
specified for the lower speed LVM scenario (i.e., SV speed of 40.2 
kph (25 mph) and POV speed of 16.1 kph (10 mph)).
---------------------------------------------------------------------------

Summary of Comments
Speed Reduction is Appropriate
    Most respondents (Auto Innovators, BMW, DENSO, GM, HATCI, Honda, 
IIHS, Intel, Subaru, Tesla, and Toyota) favored a speed reduction 
performance criterion in lieu of ``no contact'' because of its 
implication for safety benefits. BMW, DENSO, IIHS, and Subaru stated 
that speed reduction was appropriate for all AEB test scenarios because 
it mitigates crash severity, thus reducing vehicle damage, the risk of 
injury, and injury severity. Similarly, GM voiced that, under many 
conditions (e.g., speeds above 40 kph (24.9 mph) for the tested 
scenarios), current systems do not have the capability to completely 
avoid a crash, and as such, speed reduction provides the ``most 
relevant measurable safety benefit'' for AEB systems because it 
directly correlates to injury risk. Therefore, the automaker suggested 
the Agency should assess speed reduction at test speeds ranging from 40 
to 60 kph (24.9 to 37.3 mph). IIHS objected to a ``no contact'' 
criterion whether the Agency proceeds with single trials, multiple 
trials, or single trials with follow-up trials. Like GM, Honda and Auto 
Innovators also asserted that many current AEB systems will not be able 
to achieve complete crash avoidance at higher speeds but will still 
provide a significant speed reduction. Honda and Auto Innovators, in 
addition to HATCI, stated that they were opposed to a ``no contact'' 
criterion because such an approach (i.e., pass/fail) does not 
accurately reflect the safety benefits inherent to speed reductions. 
Auto Innovators cited DOT HS 813 194 to highlight the influence speed 
reduction can have on crash severity.\124\
---------------------------------------------------------------------------

    \124\ NHTSA Traffic Safety Facts: Speeding 2019 Data, DOT HS 813 
194 (Published October 2021).
---------------------------------------------------------------------------

    Auto Innovators and HATCI recommended NHTSA adopt a sliding scale 
with points awarded to systems that successfully avoid a crash and also 
those that provide speed reduction (at least for ``the most challenging 
situations'' (Auto Innovators)), with the former receiving full points 
and the latter receiving partial credit to better differentiate 
performance among the fleet.\125\ This approach is similar to that of 
Euro NCAP. Auto Innovators added points should be determined based on 
the corresponding injury risk gleaned from real-world data, and HATCI 
mentioned points should progressively decrease with decreasing speed 
reduction until the speed reduction does not provide statistically 
significant safety benefits. BMW mentioned that basing AEB performance 
assessments on speed reduction instead of pass/fail criteria would 
``more accurately'' rate AEB systems and allow ratings to be

[[Page 95949]]

more easily adjusted in the future. Honda and Auto Innovators 
recommended the Agency adopt maximum allowable collision speed as a 
performance criterion for higher-speed test conditions (i.e., SV speeds 
of 70 and 80 kph (43.5 and 49.7 mph) per Auto Innovators). Although 
HATCI favored a scoring approach based on speed reduction like that 
used by Euro NCAP, it noted that specifying a maximum allowable impact 
speed for all test conditions in lieu of ``no contact'' would also be 
acceptable.
---------------------------------------------------------------------------

    \125\ European New Car Assessment Programme (Euro NCAP) 
(November 2022), Assessment Protocol--Safety Assist--Collision 
Avoidance, Version 10.2.
---------------------------------------------------------------------------

    Adopting performance-based criteria (i.e., speed reduction) in lieu 
of pass/fail criteria (i.e., ``no contact'') was also preferred by 
Toyota for similar reasons to those already mentioned. Specifically, 
the manufacturer stated that performance-based criteria, such as speed 
reduction, can be associated with reducing injuries and fatalities to 
better represent real-world ADAS performance. The commenter also stated 
that adopting a speed reduction performance criterion could reduce the 
number of trials that are necessary (due to system variations) for 
vehicle assessments, which would ultimately reduce test burden. 
Therefore, like Auto Innovators, the automaker recommended assigning 
points for both crash mitigation and avoidance.
    Intel and Subaru suggested NHTSA adopt Euro NCAP's speed reduction 
approach for the Agency's CIB and DBS tests, with the latter commenter 
referencing Euro NCAP Assessment Protocol--Safety Assist Collision 
Avoidance v10.0.\126\ Intel suggested that it is important for NHTSA to 
distinguish between those systems that afford at least partial speed 
reduction and those that offer no speed reduction, especially at higher 
initial test speeds.
---------------------------------------------------------------------------

    \126\ See figure provided by Intel and Euro NCAP Assessment 
Protocol--Safety Assist Collision Avoidance v10.0 for Subaru.
---------------------------------------------------------------------------

    Like Auto Innovators and HATCI, Rivian suggested that the Agency 
award points for speed reduction (at least for certain scenarios) in 
addition to having a ``no contact'' criterion to encourage 
manufacturers to continuously improve system performance for those 
scenarios. FCA, Bosch, and GM shared a similar sentiment. FCA suggested 
it may be appropriate to require ``no contact'' for LVS tests with 
speeds up to 30 kph (18.6 mph), but speed reduction should generally be 
required for higher test speeds since the ``prediction time increases'' 
for such conditions. The commenter stated a requirement of ``no 
contact'' may cause higher false positive rates, resulting in system 
deactivation in the real world. Bosch opined that ``no contact'' is an 
appropriate performance criterion for test speeds up to 60 kph (37.3 
mph) but stated that points should be awarded for speed reductions as 
low as 10 kph (6.2 mph) for higher speed test conditions.
No Contact Is Appropriate
    A few commenters asserted a performance criterion of ``no contact'' 
was appropriate for the Agency to adopt for its NCAP AEB testing. CAS 
expressed that ``no contact'' is the most appropriate performance 
criterion for the Agency's AEB tests since the desired outcome of any 
CIB or DBS activation is to avoid contact. CAS also asserted that ``no 
contact'' serves as a useful criterion for consumers when comparing 
vehicles, especially as speeds are increased. Finally, it stated that 
if the Agency found that a vehicle exhibited contact as test speeds 
were progressively incremented, then it should ``regressively test at 
lower speeds'' to determine ``the maximum `no contact' speed,'' which 
could then be used as the baseline to compare vehicles.
    Adasky commented that AEB systems should afford ``no contact'' even 
at higher test speeds and at night since thermal cameras are available 
and can help systems perform well under these conditions. Advocates 
stated that a ``no contact'' requirement is ``essential,'' but also 
suggested that the Agency consider assigning credit to systems that 
offer ``meaningful'' speed reductions for tested speeds that fall 
outside of the range of performance afforded by current systems--both 
lower and higher.
Response to Comments and Agency Decisions
    The Agency is proceeding with adopting a ``no contact'' criterion 
for NCAP's AEB performance test requirements. Such a criterion is 
feasible to achieve, consistent with the safety need, and necessary to 
ensure test repeatability, among other reasons.
    Recent AEB testing has shown that several vehicles from the modern 
fleet were able to avoid contacting the vehicle test device for most of 
the test conditions adopted herein. For instance, one vehicle model 
provided complete avoidance in most of the adopted test conditions. 
This model did not provide full avoidance when tested using a 12 m 
(39.4 ft.) headway and 0.4g POV deceleration, so the more stringent 
0.5g deceleration NCAP test condition using the same 12 m (39.4 ft.) 
headway was not performed. However, the vehicle's relative impact speed 
for the 0.4g deceleration condition was relatively low, at 9.5 kph (5.9 
mph) during the first trial. Consequently, it is reasonable to expect 
that minor changes could be made to the vehicle model's AEB system such 
that it would be able to pass the CIB LVD, 12 m (39.4 ft.) headway and 
0.5g POV deceleration condition in the near future. Another vehicle 
model provided full avoidance in nearly every test condition, failing 
to completely avoid contact with the POV in only the CIB LVS test 
scenario. For this test scenario, the vehicle provided complete 
avoidance at test speeds through 60 kph (37.3 mph), and at 70 kph (43.5 
mph), the vehicle provided partial speed reduction. Since full 
avoidance was not observed at 70 kph (43.5 mph), the vehicle was not 
subsequently tested at 80 kph (49.7 mph). Thus, while several 
commenters mentioned that tested vehicles may currently have difficulty 
with completely avoiding contact with the vehicle test device, the 
aforementioned results suggest that the test requirements are practical 
for vehicles to achieve in the near future. Furthermore, manufacturers 
of these vehicles have shown that a ``no contact'' performance 
criterion can be met with no increase to false positive rates, even at 
higher test speeds, which was a concern expressed by FCA. To date, 
NHTSA has not received an increased number of false positive reports 
for either vehicle.
    In response to Rivian and FCA's statements that adopting speed 
reduction as a performance criterion would encourage manufacturers to 
continuously improve system performance, particularly at higher test 
speeds, applying a ``no contact'' performance criterion should achieve 
the same goal. Vehicle manufacturers that wish to obtain NCAP credit 
for AEB must have vehicles that offer exceptional, robust system 
performance. Although it may be true that there are inherent safety 
benefits to adopting a maximum allowable impact speed or speed 
reduction performance criterion, as numerous commenters asserted, there 
are more profound safety benefits afforded by systems that offer 
complete crash avoidance. By promoting development of more robust AEB 
systems capable of much higher speed reductions and complete crash 
avoidance, AEB systems may effectively address a larger percentage of 
crashes that cause serious injuries and/or fatalities.
    It would be most advantageous to establish a ``no contact'' 
performance criterion for several other reasons. From a testing 
logistics perspective, the Agency has observed that it is possible for 
even relatively low-speed collisions with the lead vehicle test device 
to

[[Page 95950]]

damage the SV during testing. In such instances, camera or radar 
sensors on the vehicle may become misaligned such that subsequent runs 
might not be representative of the vehicle condition at the time of 
first sale. Further, striking the vehicle test device might prematurely 
degrade the appearance of the device and modify its specifications, 
including in ways not immediately observable. As mentioned previously, 
damage to the test device might affect the radar cross section and may 
require a lengthy verification procedure to discover. As such, vehicle 
contact which does not result in immediate test failure may introduce 
repeatability concerns, time-consuming interruptions to testing, and 
higher costs.
    As mentioned in the March 2022 RFC notice, the Agency is not 
proposing a full-scale rating system for crash avoidance technologies 
at this time. NHTSA plans to continue to use check marks to give credit 
to vehicles that are equipped with the recommended ADAS technologies 
and pass the applicable system performance test requirements for each 
ADAS technology included in NCAP until it issues a final decision 
notice announcing the new ADAS rating system. Therefore, at this time, 
the Agency cannot adopt a points-based system for speed reductions, as 
Auto Innovators, HATCI, Toyota, and Rivian suggested.
    Regarding Toyota's comment that adopting a speed reduction 
performance criterion could reduce the number of trials necessary for 
vehicle assessments and therefore reduce test burden, the Agency's 
planned testing approach (discussed in the next section) will 
effectively address this concern.
    Finally, the Agency agrees with CAS that it will be easier to 
communicate test results to consumers if the passing criterion is 
straightforward (``no contact'') compared to a passing criterion based 
on speed reduction or maximum allowable impact speed. NHTSA also 
recognizes, as the respondent suggested, that full avoidance is likely 
the result that most consumers desire from an AEB system.
e. Number of Trials
    Currently, NHTSA's AEB test procedure requires that a vehicle meet 
performance criteria (i.e., a specified speed reduction) for five out 
of seven trials. In its March 2022 proposal, however, the Agency 
suggested that a new testing approach may be more appropriate given the 
changes proposed for its AEB tests.
    Per NHTSA's March 2022 RFC, only one valid test trial (i.e., a 
trial in which all test specifications and tolerances are satisfied) 
would be conducted per each incremented test speed (i.e., 40, 50, 60, 
70, and 80 kph or 24.9, 31.1, 37.3, 43.5, and 49.7 mph (as applicable 
for each test scenario)) \127\ as long as the SV did not contact the 
POV test device. If the SV were to contact the POV during a test trial, 
and the relative longitudinal velocity between the SV and POV was less 
than or equal to 50 percent of the initial speed of the SV, NHTSA 
proposed that it would then perform four additional (repeated) test 
trials at the same speed for which the impact occurred. The Agency 
proposed that the SV could not contact the POV for at least three out 
of the five test trials performed at that same speed to pass that 
specific combination of test scenario and test speed (i.e., test 
condition).\128\ If the SV contacted the POV during a valid trial of a 
test condition (whether it be the first test performed at a particular 
test speed or a subsequent test trial at that same speed), and the 
relative impact velocity exceeded 50 percent of the initial speed of 
the SV, no additional test trials would be conducted at the given test 
speed (or for the test scenario) and the SV would fail the test 
condition.
---------------------------------------------------------------------------

    \127\ NHTSA's proposal included several assessment alternatives 
for the LVD test scenario. These included testing one speed, 50 kph 
(31.1 mph); two speeds, 50 kph (31.1 mph) and 80 kph (49.7 mph); or 
four speeds, 50, 60, 70, and 80 kph (31.1, 37.3, 43.5, and 49.7 
mph).
    \128\ The Agency notes that a similar pass/fail criterion (i.e., 
a vehicle must meet performance requirements for three out of five 
trials for a particular test condition to pass the test condition) 
is included in its current LDW test procedure, as referenced later 
in this document.
---------------------------------------------------------------------------

    Because the Agency had proposed additional test speeds (compared to 
its current assessments) for the various AEB test scenarios, NHTSA 
asserted this assessment approach would reduce test burden while 
continuing to ensure that passing AEB systems represent robust designs 
that offer a high level of performance and safety. In its March 2022 
RFC, the Agency sought comment on whether this proposed assessment 
method was appropriate or whether an alternative method, such as 
subjecting the vehicle to multiple trials, should be adopted instead. 
For respondents preferring multiple trials, NHTSA asked how many trials 
would be appropriate and what an acceptable pass rate would be. 
Further, for those respondents who favored the proposed assessment 
method, NHTSA asked whether such a method would also be acceptable in 
instances where only one or two test speeds were selected for 
inclusion, such as for the LVD test scenario,\129\ or whether it would 
be more appropriate in such instances to alternatively require seven 
trials for each test speed and additionally require that five out of 
the seven trials conducted pass the ``no contact'' performance 
criterion.
---------------------------------------------------------------------------

    \129\ For the LVD test scenario, NHTSA proposed to adopt an SV 
and POV test speed of 50 kph (31.1 mph) (i.e., one test condition) 
but also sought comment on whether it would be appropriate to 
incorporate additional SV and POV test speeds of 60, 70, and 80 kph 
(37.3, 43.5, and 49.7 mph, respectively). Furthermore, for DBS 
specifically, the Agency sought comment on whether it was reasonable 
to only conduct LVS and LVM tests at only the highest two test 
speeds proposed for CIB--70 and 80 kph (43.5 and 49.7 mph) (i.e., 
two test conditions). A similar comment request was made for the LVD 
DBS test, if NHTSA decided to adopt those same higher test speeds 
(i.e., 70 and 80 kph (43.5 and 49.7 mph)) for the CIB LVD test.
---------------------------------------------------------------------------

Summary of Comments
    A few commenters generally agreed with the Agency's proposal to 
conduct one trial per test speed with speed increments of 10 kph (6.2 
mph) and to only perform repeated trials in the event of POV contact. 
Rivian was one such commenter, stating that the proposed AEB test 
method was ``practical,'' as 10 kph (6.2 mph) test speed increments 
should sufficiently highlight performance degradations such that 
multiple trials at a given speed should not be necessary, thus reducing 
test burden. Likewise, IDIADA commented that performing one trial per 
test speed across many different speeds was sufficient to ensure system 
robustness. DRI also supported the Agency's proposal for AEB testing, 
explaining that their experience has shown that CIB and DBS systems 
typically do not have difficulty detecting lead vehicles and are able 
to do so repeatedly such that inconsistent results generally stem from 
poor system performance rather than detection capabilities.
    HATCI and Honda also generally agreed with the Agency's proposal. 
The manufacturers were in favor of completing an additional four runs 
after the first failed (i.e., contact) run and supported the proposed 
pass rate of three out of five total runs. However, Honda commented 
that additional trials should be conducted even if the AEB system does 
not impart a 50 percent relative speed reduction in the first trial 
run. The automaker expressed that stopping the test after one failed 
run may be ``overly strict'' and ``premature'' given potential 
variations in test conditions.
    BMW supported test speed increments of 10 kph (6.2 mph) and the 
Agency's proposal to conduct four additional runs in the event of 
contact if NHTSA ultimately adopted a ``no contact'' (i.e., pass/fail) 
criterion. Having noted this, the automaker, along

[[Page 95951]]

with several other commenters, expressed strong support for adopting 
assessment criteria based on speed reduction instead. With speed 
reduction as the assessment criterion (instead of ``no contact''), BMW 
supported conducting two additional trials after the first run failure 
(i.e., contact) and then using the median speed for all three trial 
runs as the true impact speed for rating purposes.
    Auto Innovators and FCA also generally supported the Agency's 
proposal for AEB testing (i.e., one trial per test speed) but suggested 
that a pass rate of two out of three would be acceptable in instances 
of contact during the first trial run for a test condition to reduce 
test burden. However, like BMW, both groups also stated that the Agency 
should recognize the inherent safety benefits afforded by crash 
mitigation (i.e., speed reduction) in addition to complete crash 
avoidance. In the same vein, Auto Innovators asserted that the Agency's 
current proposal, which would prohibit test conduct for higher speeds 
if lower speeds did not result in crash avoidance, ``may 
unintentionally penalize systems that have robust higher-speed 
performance.'' Accordingly, the group suggested that (1) conducting 
higher-speed trial runs should not be contingent on a 50 percent 
relative speed reduction for lower speed runs and/or (2) testing for a 
scenario should continue regardless of whether the relative speed 
reduction in one trial is less than 50 percent. Instead, Auto 
Innovators suggested the Agency consider assigning ``partial credit'' 
to systems that perform worse at lower speeds. Whereas BMW recommended 
using the median speed of all three trials to assign vehicles' AEB 
performance ratings, FCA suggested NHTSA average the impact speed for 
the trials conducted when impact occurs. FCA further noted it would 
prefer ``further definition'' for LVD tests at test speeds greater than 
60 kph (37.3 mph) before settling on an assessment method for these 
test conditions.
    In general, GM favored optimizing the number of test conditions 
rather than reducing the number of test runs. The manufacturer noted 
the former does more to reduce overall test burden and the latter leads 
to a diminished understanding of system performance variation. However, 
in this instance, the automaker reasoned that the Agency's proposal 
would ``speed up the test, and only repeat trials when necessary,'' so 
they were supportive of the proposed three out of five pass rate if the 
Agency adopted a ``no contact'' performance criterion. However, the 
automaker, like many others, favored speed reduction as the performance 
criterion for higher speeds in lieu of ``no contact.'' More 
specifically, GM recommended the Agency adopt a 30 kph (18.6 mph) 
relative impact speed (instead of full avoidance) as the minimum 
performance criterion for SV speeds above 50 kph (31.1 mph). The 
manufacturer suggested that additional trials should be performed for 
those vehicles having a relative impact speed of 30 kph (18.6 mph) or 
less, and either the mean or median of the resulting velocity 
reductions should be used for scoring.
    While Rivian stated that the Agency's proposal of testing across 
multiple speeds instead of multiple trials at the same speed would 
ensure system robustness, Intel stated that conducting multiple trials 
was ``more robust.'' However, to limit test burden, Intel suggested, 
like others, that a pass rate of two out of three trials was 
appropriate for a given test condition. The company also agreed in 
sentiment with others' recommendation that the Agency recognize the 
safety benefits inherent to speed reductions, and Honda's assertion 
that stopping a test because of one run at a lower speed that doesn't 
produce at least a 50 percent speed reduction may be too extreme. As 
such, Intel also proposed an alternative test procedure to further 
reduce test burden.
    For its proposed procedure, Intel suggested that instead of 
performing the entire AEB test matrix, NHTSA should select a random 
subset of tests (i.e., test conditions) to be performed based on test 
results for the complete matrix provided by vehicle manufacturers. The 
first trial of the first selected test condition would then be 
performed. If the speed reduction for that trial meets a ``predicted'' 
speed reduction, points applicable to the actual speed reduction would 
be awarded and the first trial of the next randomly selected test 
condition would then be performed. If the speed reduction for the first 
trial was insufficient (i.e., did not achieve the ``predicted'' speed 
reduction), an additional two trials would be conducted (as mentioned 
previously). If both of those trial runs achieved the ``predicted speed 
reduction,'' points applicable to the actual speed reduction would be 
awarded and testing would continue with the next randomly selected test 
condition. If the ``predicted'' speed reduction was not met for at 
least two of the three trials conducted for a given test condition, 
then the test would cease, and partial points would be awarded based on 
the average speed reduction recorded for the three trials. Intel also 
suggested the Agency should apply a penalty, as is done by Euro NCAP, 
for instances where the actual speed reduction is less than the 
``predicted'' speed reduction.
    Tesla also stated it supported adopting performance criteria based 
on speed reduction in lieu of a ``no contact'' pass/fail criterion (for 
both CIB and DBS). Unlike the other commenters who expressed a similar 
sentiment and proposed that three trials should be conducted upon 
impact, Tesla supported the Agency's original proposal of requiring 
that an additional four runs be conducted after the initial trial run 
(for five runs total). For those additional four runs, Tesla asserted 
the vehicle should have to achieve a speed reduction of 75 percent or 
more of the initial SV speed to obtain a passing result for that test 
condition. If the vehicle was to achieve passing results for that test 
condition, then the speed would be incremented to the next test speed 
and the process would repeat until the vehicle either could not exceed 
a 75 percent speed reduction, or the 80 kph (49.7 mph) test condition 
was passed, whichever came first.
    CAS stated that NHTSA's assessments should be based on objective 
reliability and confidence criteria, noting that passing 7 out of 7 
trials at any speed provides 91 percent reliability of the AEB system 
with only 50 percent confidence. Therefore, CAS contended that no fewer 
than 7 successful trials and no failures should be acceptable at any 
speed.
    As previously mentioned, Auto Innovators did not favor a pass rate 
of five out of seven runs since this pass rate would not optimize test 
resources. Notwithstanding, the group remarked that if the Agency did 
impose a five out of seven requirement and the first five runs produced 
passing results (i.e., no contact), then the last two runs should not 
be conducted in order to reduce test burden.
    Other commenters provided general comments on this topic. For 
example, Toyota stated the Agency should conduct the number of trials 
that were sufficient to communicate accurate performance information to 
consumers, without recommending a specific number. Advocates asserted 
that the Agency should justify how the number of trials and pass/fail 
criteria adopted will assure that evaluated systems will perform as 
expected and address the safety need, especially since NHTSA's testing 
is conducted under controlled conditions.

[[Page 95952]]

Response to Comments and Agency Decisions
    The Agency sought feedback on the proposed number of trials within 
each test variant. The Agency also asked commenters to consider a 
potential ADAS rating system that would allow flexibilities for 
continuous improvements to the program and cross-model year 
comparisons. Based on comments received on the appropriate number of 
trials for each test variant, NHTSA has decided that instead of 
performing multiple trials for each assessed test condition for a given 
test scenario, as is currently done for NCAP testing, it will conduct 
one trial per test condition (e.g., at a prescribed test speed for a 
given test condition/scenario) for future AEB NCAP tests. In the event 
the SV contacts the POV during a trial, testing will cease for the test 
condition, respective test scenario, and the AEB test being performed 
(i.e., CIB or DBS). Effectively, the vehicle will fail the individual 
test condition/scenario being assessed, and it will not receive NCAP 
credit for the ADAS system being evaluated, whether it be CIB or DBS.
Number of Trials Required for Each Test Condition
    Since the Agency will run only one valid trial per test condition, 
per NHTSA's finalized CIB testing approach, the Agency will conduct, at 
most, five LVS tests, five LVM tests, eight LVD tests, and one false 
positive test. For DBS, NHTSA will conduct, at most: four LVS tests, 
four LVM tests, eight LVD tests, and one false positive test. This 
results in a maximum total of 19 CIB test trials and 17 DBS test 
trials, or 36 total AEB trials.
    Although several commenters, like Intel and CAS, stated the Agency 
should or must continue to conduct multiple trials per test condition, 
many other commenters (Auto Innovators, FCA, GM, HATCI, Honda, and BMW) 
asserted that NHTSA's planned testing approach was appropriate. There 
are several reasons that a testing approach requiring one trial run per 
test condition, instead of multiple runs, is appropriate for the 
Agency's AEB testing in NCAP. First, NHTSA notes that DRI attested 
that, from its own experience with AEB testing, systems exhibiting 
better performance tend to do so repeatably. DRI's observation for 
superior AEB systems partially counters CAS's assertion that conducting 
a single trial for a given test condition would be insufficient. With 
respect to less robust AEB systems, the Agency acknowledges that, 
occasionally, a vehicle may pass the first trial for a given speed even 
though it may fail subsequent trials if additional trials were to be 
conducted at that same speed. However, NHTSA also asserts that the 
system's poor performance could alternatively be exposed in single 
trials conducted for progressively higher speeds, which is the approach 
the Agency has adopted for its LVS and LVM tests.\130\ As such, the 
Agency agrees not only with IDIADA, which stated that an approach that 
requires one trial per test speed across many different speeds should 
effectively assure system robustness, but also with Rivian, which noted 
that such an approach should effectively identify changes in system 
performance without the need to conduct multiple runs for each test 
condition. Further, NHTSA asserts its planned testing approach of 
incrementing test speeds should also reduce the risk of damage to the 
SV and POV.
---------------------------------------------------------------------------

    \130\ The Agency will increment test speeds by 10 kph (6.2 mph) 
from a minimum to a maximum speed.
---------------------------------------------------------------------------

    Performing one trial run per test condition is also reasonable for 
NCAP's LVD tests. Although NHTSA plans to assess only two discrete test 
speeds for the LVD scenario rather than a range of speeds as planned 
for the LVS and LVM scenarios, NHTSA reasons this approach should still 
ensure system robustness for the LVD AEB tests. As mentioned earlier, 
since the SV and POV speeds are initially the same in the LVD tests, 
the initial speed conditions for the decelerating lead vehicle scenario 
are not as critical to the outcome of the test as the other main 
parameters, headway and POV deceleration. It should be noted, though, 
that a higher initial test speed inherently requires additional braking 
to achieve a complete stop compared to a lower initial test speed. 
Thus, by adopting two discrete test speeds, two different headways, and 
two POV deceleration magnitudes, as well as structuring testing such 
that it progresses from generally the least challenging to the most 
challenging parameters, it will still ensure AEB systems receiving NCAP 
credit for passing test results represent robust designs offering a 
high level of performance and safety without increasing test burden 
unnecessarily.
    Second, NHTSA's testing approach is reasonable for NCAP because it 
best manages test burden. Per CAS' comments, the Agency can only be 50 
percent confident that AEB systems will be 91 percent reliable when 
seven runs are conducted for each test condition. This means that NHTSA 
would have to perform a far greater number of runs for each test 
condition to have a reasonably high confidence that the observed system 
performance is representative of the system's true capability.\131\ 
Alternatively, the Agency could consider conducting a large number of 
runs at only the highest test speed for each test scenario. However, it 
would risk imparting additional damage to the test vehicle and test 
equipment in addition to test delays due to repairs if it were to take 
such an approach.\132\
---------------------------------------------------------------------------

    \131\ Three hundred trials would be needed for 99 percent 
reliability with 95 percent confidence. Similarly, 59 trials would 
be needed for 95 percent reliability with a 95 percent confidence, 
and 29 trials would be needed for 90 percent reliability with 95 
percent confidence.
    \132\ Since the vehicle tested is randomly purchased or leased 
from dealerships, its performance in the AEB tests is based on the 
performance and manufacturing reliability set by the manufacturer.
---------------------------------------------------------------------------

    Third, permitting some number of failures, which would be inherent 
to repeated trials, would be detrimental to real-world safety. 
Considering NCAP testing will be limited to only certain conditions in 
a controlled testing environment, allowing no test failures is the most 
acceptable approach and will best ensure consistency in real world AEB 
system performance and safety improvement in rear-end crashes.
    The aforementioned considerations make the Agency's planned testing 
approach the most appropriate for NCAP testing. Because NHTSA has 
decided to adopt an approach requiring only one trial per test 
condition, it is not necessary to evaluate a random subset of test 
conditions to limit test burden, as Intel suggested.
Repeat Trials in the Event of Contact
    NHTSA's RFC notice proposed performing four additional (repeated) 
test trials at the same test speed if the SV contacted the POV during 
the first test trial for a given AEB test condition and the relative 
longitudinal velocity between the SV and POV was less than or equal to 
50 percent of the initial speed of the SV. To pass the test condition, 
NHTSA proposed that the SV could not contact the POV for at least three 
out of the five total trials conducted. The Agency also proposed that 
if the SV contacted the POV during a valid trial of a test condition 
(whether it be the first test performed at a particular test speed or a 
subsequent repeat run conducted at that same speed), and the relative 
longitudinal impact velocity exceeded 50 percent of the initial speed 
of the SV, no additional test trials would be conducted at the given 
test speed (or for the test scenario) and the SV would fail the test 
condition.

[[Page 95953]]

The Agency has decided not to finalize this part of its proposal and 
will thus not conduct repeat trials in the event of SV-to-POV contact, 
regardless of the relative longitudinal impact velocity recorded 
between the two vehicles at the time of impact.
    Many commenters (Auto Innovators, BMW, FCA, GM, HATCI, Honda, 
Rivian, and Tesla) agreed, at least in part (some differed on the pass 
rate), with the Agency's proposal to conduct additional trials if an 
initial trial run resulted in contact, and most of these commenters 
(Auto Innovators, BMW, FCA, GM, Honda, and Rivian) stated that NHTSA 
should consider conducting multiple trials regardless of whether a 50 
percent speed reduction was observed in the first or subsequent trial 
runs. However, based on other comments received and laboratory testing 
experience, NHTSA reasons it is no longer appropriate to conduct repeat 
trials in the event of contact.
    Specifically, the Agency's underlying objective in updating NCAP is 
to adopt AEB tests that are representative of real-world rear-end 
crashes and maximize safety. To achieve these goals, NHTSA must 
establish performance criteria for testing that will ensure AEB system 
response is consistent and repeatable. Similar to DRI's observations 
during AEB testing, the Agency has observed that if a vehicle contacts 
the vehicle test device during the first trial run for a test 
condition, it is also likely to contact the vehicle test device during 
subsequent runs conducted.\133\ In the Agency's testing, if an impact 
occurred and additional tests were performed for that test condition, 
at least one more impact was observed 97 percent of the time (32 of 33 
applicable test conditions) for CIB tests, and for 100 percent of the 
DBS tests (27 of 27 of the applicable test conditions). Considering all 
CIB and DBS trials, the total was 98 percent (59 of 60 total trials). 
Therefore, the Agency disagrees with commenters who stated that 
discontinuing testing after a single-run failure is ``overly strict.''
---------------------------------------------------------------------------

    \133\ https://downloads.regulations.gov/NHTSA-2023-0021-0006/attachment_2.pdf.
---------------------------------------------------------------------------

    Encouraging robust system performance that limits contact will lead 
to a reduction of harm and costs associated with crashes, and result in 
fewer testing delays and costs caused by SV-to-POV contact, benefiting 
both the public and the Agency. Based on this, NHTSA does not agree 
with concerns raised by several commenters who expressed that 
discontinuing testing after failures at low speeds may be ``premature'' 
or may unfairly penalize vehicles that offer more robust AEB system 
performance at higher test speeds. Specifically, NHTSA notes that a 
lower speed rear-end crash resulting in an injury still causes an 
unnecessary injury, and still imposes an economic cost. As such, 
requiring crash avoidance performance across the range of speeds and 
test conditions defined in the NCAP AEB test matrix is imperative to 
maximize safety.
    The Agency also agrees with Toyota that it should only conduct the 
number of test trials necessary to provide consumers with accurate 
information pertaining to AEB system performance. Allowing repeated 
trials in the event of SV-to-POV contact may mislead consumers, 
potentially causing them to assume that a vehicle's AEB system provides 
more repeatable, robust crash avoidance performance than it does. As 
such, it is most appropriate to provide consumers with an assessment of 
system performance using a single, representative sample rather than an 
assessment based on the average or median impact speed across several 
runs, as some commenters suggested. Manufacturers must design their 
vehicles to meet the adopted performance criteria every time. By 
proceeding in this manner, the Agency is responding to Advocates' 
request to best ensure the number of trial and performance criteria 
adopted will assure that evaluated systems will perform as expected and 
best address the safety need.
f. Pass Rate
    The Agency sought comment on an appropriate minimum pass rate to 
evaluate AEB performance based on the adjustments it proposed for its 
AEB assessments. The proposal included plans to (1) consolidate its FCW 
and CIB tests such that the CIB tests would also serve as an indicant 
of FCW operation, (2) assess up to 14 test speeds for CIB (i.e., five 
for LVS, five for LVM, and potentially four for LVD), and (3) assess up 
to six test speeds for DBS (two for LVS, two for LVM, and potentially 
two for LVD), which would result in a total of up to 20 unique 
combinations of test conditions to be evaluated for AEB. As an example, 
the Agency suggested that a vehicle could be considered to meet the AEB 
performance if it passes two-thirds of the 20 unique combinations of 
test conditions (i.e., passes 14 unique combinations of test 
conditions).
Summary of Comments
    Bosch favored a pass rate of two-thirds of the 20 unique 
combinations but stated that any vehicles not able to meet this 
criterion should be awarded partial credit. BMW, Honda, and Auto 
Innovators also commented that a pass rate of two-thirds is reasonable. 
However, to ensure that both CIB and DBS performance is weighted 
equally, Honda suggested (as mentioned earlier) that the Agency should 
add DBS tests at lower speeds (40, 50, and 60 kph) to align with CIB 
performance evaluations that are also conducted at those speeds.
    Tesla favored a pass rate of 70 percent for CIB and DBS tests 
overall (i.e., 70 percent of all test conditions assessed for the 
specified test scenarios) since this would generally be consistent with 
current NCAP test procedures, which require a pass rate of five out of 
seven trials.
    CAS asserted that the only appropriate pass rate is 100 percent, 
stating that the number of trials proposed by the Agency was 
``insufficient to establish high confidence in safe performance even 
with no failures.''
Response to Comments and Agency Decisions
    NHTSA has decided to adopt a 100 percent pass rate for CIB and DBS 
system testing and will provide consumers with an overall assessment of 
AEB performance, as proposed. This means AEB systems must achieve 
passing results (i.e., no POV-to-SV contact) in all adopted test 
conditions for both CIB and DBS (i.e., 19 test conditions for CIB--five 
for LVS, five for LVM, eight for LVD, and one false positive; and 17 
test conditions for DBS--four for LVS, four for LVM, eight for LVD, and 
one false positive) to receive credit for AEB technology. The Agency 
will not provide separate credit for CIB and DBS passing performance; 
only those vehicles achieving passing performance for all 36 AEB test 
conditions will receive NCAP credit for passing AEB performance.
    The Agency's decision to adopt a pass rate of 100 percent and 
combine CIB and DBS performance into an overall assessment for AEB is 
appropriate for several reasons. First, NHTSA agrees with CAS that no 
test failures should be allowed for any test scenarios/conditions. This 
is the best way to ensure that only the most robust AEB systems obtain 
AEB credit on the Agency's website. Adopting a pass rate of two-thirds 
or seventy percent, as some commenters suggested, or awarding partial 
credit, as Bosch requested, does not best serve the motoring public. As 
mentioned previously, the only way to ensure AEB systems afford 
meaningful safety is to require vehicles to avoid contact for every 
test condition assessed. Further, since the goal of NCAP is to provide

[[Page 95954]]

consumers with information to inform their vehicle buying choices, 
communicating information on the functionality of a vehicle's entire 
AEB system, rather than its individual system components, would be more 
beneficial at this time. The Agency reasons that consumers' new vehicle 
selection criteria will not include a consideration of whether they 
anticipate braking or not when faced with a crash-imminent situation. 
Rather, they will want to purchase a vehicle that responds 
appropriately to prevent the crash regardless of their action(s) or 
inaction. As such, providing separate ratings for CIB and DBS 
performance would be unhelpful in this regard. NHTSA also does not want 
to mislead consumers in assuming AEB system performance is better than 
it is by assigning credit to a vehicle for passing DBS performance when 
its CIB performance was lackluster. This is particularly concerning 
since, as mentioned, NHTSA found in its analysis of 2003-2009 NASS-CDS 
data that drivers of an SV involved in a rear-end crash tended to brake 
at about the same rate as those who did not brake, thus making 
performance for both system components equally important.\134\ Yet, the 
Agency's research testing for model year 2021-2022 vehicles suggested 
that no vehicle exhibited passing performance for both AEB 
technologies, although one vehicle achieved passing results for one 
technology, DBS.\135\ Nonetheless, NHTSA believes that achieving a pass 
rate of 100 percent for CIB and DBS testing is feasible. The Agency 
notes that the vehicle which provided passing performance for all DBS 
tests also achieved no contact performance for 16 of the 18 assessed 
CIB test conditions. While contact was observed for the 12 m headway, 
0.4g deceleration LVD CIB test condition (such that the 12 m headway, 
0.5g deceleration LVD CIB test condition was not subsequently 
performed), the vehicle exhibited a relative impact speed of less than 
10 kph during all runs performed. Considering the vehicle's robust 
performance overall for the overwhelming majority of the AEB tests 
conducted, NHTSA believes that minor changes to the system's software 
should afford a perfect pass rate overall.
---------------------------------------------------------------------------

    \134\ National Highway Traffic Safety Administration (2012, 
June), Forward-looking advanced braking technologies research 
report, https://www.regulations.gov/document?D=NHTSA-2012-0057-0001.
    \135\ National Highway Traffic Safety Administration. (2023, 
February). NHTSA's 2022 Light Vehicle Automatic Emergency Braking 
Research Test Summary. http://www.regulations.gov. Docket No. NHTSA-
2023-0021-0005. This statement is based on the results of the 
Agency's model year 2021-2022 research test data, which did not 
include the LVD test conditions that require a 0.3g POV 
deceleration.
---------------------------------------------------------------------------

    Since the number of tests adopted for NCAP's CIB assessments is 
nearly identical to the number adopted for the program's DBS 
assessments (i.e., 19 tests for CIB versus 17 for DBS), there is no 
need to weight either set of assessments (i.e., those for CIB or DBS), 
as Honda requested, especially since vehicles must achieve a pass rate 
of 100 percent for each of the two AEB technologies to receive credit 
for both.
    An overview of test scenarios and conditions that will be required 
to receive passing credit for AEB systems in NCAP is shown in Tables 14 
and 15.

                               Table 14--Adopted CIB Test Scenarios and Conditions
----------------------------------------------------------------------------------------------------------------
                                                                                    POV
    Test No.          Test scenario       SV speed    POV speed   POV headway  deceleration  Requirement to pass
                                        (kph (mph))  (kph (mph))   (m (ft.))        (g)
----------------------------------------------------------------------------------------------------------------
1...............  LVS.................    40 (24.9)            0          n/a           n/a  No SV-to-POV
                                                                                              contact during any
                                                                                              trial.
2...............                          50 (31.1)            0          n/a           n/a
3...............                          60 (37.3)            0          n/a           n/a  ...................
4...............                          70 (43.5)            0          n/a           n/a
5...............                          80 (49.7)            0          n/a           n/a
6...............  LVM.................    40 (24.9)    20 (12.4)          n/a           n/a
7...............                          50 (31.1)    20 (12.4)          n/a           n/a
8...............                          60 (37.3)    20 (12.4)          n/a           n/a
9...............                          70 (43.5)    20 (12.4)          n/a           n/a
10..............                          80 (49.7)    20 (12.4)          n/a           n/a
11..............  LVD.................    50 (31.1)    50 (31.1)   40 (131.2)           0.3
12..............                          50 (31.1)    50 (31.1)    12 (39.4)           0.3
13..............                          80 (49.7)    80 (49.7)   40 (131.2)           0.3
14..............                          80 (49.7)    80 (49.7)    12 (39.4)           0.3
15..............                          50 (31.1)    50 (31.1)   40 (131.2)           0.5
16..............                          50 (31.1)    50 (31.1)    12 (39.4)           0.5
17..............                          80 (49.7)    80 (49.7)   40 (131.2)           0.5
18..............                          80 (49.7)    80 (49.7)    12 (39.4)           0.5
19..............  False Positive (STP)    80 (49.7)          n/a          n/a           n/a  SV peak
                                                                                              deceleration
                                                                                              <0.25g.
----------------------------------------------------------------------------------------------------------------


                               Table 15--Adopted DBS Test Scenarios and Conditions
----------------------------------------------------------------------------------------------------------------
                                                                                    POV
    Test No.          Test scenario       SV speed    POV speed   POV headway  deceleration  Requirement to pass
                                        (kph (mph))  (kph (mph))   (m (ft.))        (g)
----------------------------------------------------------------------------------------------------------------
1...............  LVS.................    70 (43.5)            0          n/a           n/a  No SV-to-POV
                                                                                              contact during any
                                                                                              trial.
2...............                          80 (49.7)            0          n/a           n/a
3...............                          90 (55.9)            0          n/a           n/a
4...............                         100 (62.1)            0          n/a           n/a
5...............  LVM.................    70 (43.5)    20 (12.4)          n/a           n/a
6...............                          80 (49.7)    20 (12.4)          n/a           n/a
7...............                          90 (55.9)    20 (12.4)          n/a           n/a
8...............                         100 (62.1)    20 (12.4)          n/a           n/a
9...............  LVD.................    50 (31.1)    50 (31.1)   40 (131.2)           0.3

[[Page 95955]]

 
10..............                          50 (31.1)    50 (31.1)    12 (39.4)           0.3
11..............                          80 (49.7)    80 (49.7)   40 (131.2)           0.3
12..............                          80 (49.7)    80 (49.7)    12 (39.4)           0.3
13..............                          50 (31.1)    50 (31.1)   40 (131.2)           0.5
14..............                          50 (31.1)    50 (31.1)    12 (39.4)           0.5
15..............                          80 (49.7)    80 (49.7)   40 (131.2)           0.5
16..............                          80 (49.7)    80 (49.7)    12 (39.4)           0.5
17..............  False Positive (STP)    80 (49.7)          n/a          n/a           n/a  SV peak
                                                                                              deceleration
                                                                                              <0.25g over the
                                                                                              baseline peak
                                                                                              imparted by manual
                                                                                              braking.
----------------------------------------------------------------------------------------------------------------

g. Use of the ABD GVT and Appropriate Revision(s)
    Currently, NHTSA uses the SSV as the POV in NCAP testing of DBS and 
CIB systems. The SSV, modeled after a small hatchback passenger car, is 
fabricated from light-weight composite materials including carbon fiber 
and Kevlar[supreg].\136\ To maximize visual realism, the SSV shell is 
wrapped with a vinyl material that simulates paint on the body panels 
and rear bumper and a tinted glass rear window. Given the combination 
of a design that emphasizes being lightweight, use of a towed track to 
support movement, and its material properties, the SSV has certain 
limitations during testing; namely, the maximum speed at which it can 
operate (i.e., <=56 kph (35 mph)) and maximum relative speed at which 
the SV can strike it (i.e., 40 kph (25 mph) and lower speed). When 
operated outside of its intended operational constraints, the SSV can 
inflict damage to other vehicles and/or be damaged itself. The monorail 
used to laterally constrain the SSV is visible and secured to the test 
surface, which could potentially confound camera-based AEB systems. 
Considering these complications and constraints for testing, NHTSA 
proposed in its March 2022 RFC notice to use a GVT, mounted to a 
robotic platform, in lieu of the SSV in future AEB testing because GVTs 
do not have the same testing limitations.
---------------------------------------------------------------------------

    \136\ 80 FR 68604 (Nov. 5, 2015).
---------------------------------------------------------------------------

    A GVT, which also resembles a white hatchback passenger car, is 
meant to represent a vehicle in the subcompact to compact car class. A 
specific description of the required GVT characteristics is defined in 
International Organization for Standardization (ISO) 19206-3:2021, and 
at the time of this notice, there were two companies that produced a 
GVT as a commercially available product: AB Dynamics, Inc (ABD) and 
4activeSystems (4a).\137\ Both versions use an internal foam-based 
frame covered by multiple vinyl outer ``skin'' sections designed to 
provide the dimensional, optical, and radar characteristics of a real 
vehicle that can be recognized as such by camera and radar 
sensors.\138\ In contrast to the SSV, the available GVTs are secured 
using hook and loop fasteners to the top of a programmable robotic 
platform which facilitates their movement. When either version of the 
GVT is impacted at low speed, it is typically pushed off the robotic 
platform but remains assembled. At higher impact speeds, the ABD GVT 
breaks apart, as the SV essentially drives through it.\139\ At similar 
impact speeds, the 4a GVT is designed to remain more intact after being 
pushed off the robotic platform. Both GVT variants are designed to be 
reconstructed/reset back on top of the robotic platform after an SV-to-
POV impact occurs. NHTSA reasoned that a GVT is therefore less likely 
than the SSV to impart damage to other vehicles, particularly at higher 
impact speeds.
---------------------------------------------------------------------------

    \137\ ABD refers to their GVT product as the ``Soft Car 360'' 
and 4activeSystems refers to their GVT product as the ``4activeC2.''
    \138\ Snyder, A.C., Forkenbrock, G.J., Davis, I.J., O'Harra, 
B.C., & Schnelle, S.C., A test track comparison of the global 
vehicle target and NHTSA's strikeable surrogate vehicle, (Report No. 
DOT HS 812 698), July 2019, https://rosap.ntl.bts.gov/view/dot/41936.
    \139\ Id.
---------------------------------------------------------------------------

    In its March 2022 RFC notice, NHTSA proposed to use the [ABD] GVT 
Revision G for its future AEB assessments. This vehicle test device was 
proposed at the time because it is currently used by other consumer 
vehicle safety organizations that provide consumer information, 
including Euro NCAP,\140\ as well as many vehicle manufacturers in 
their internal testing conducted per NCAP test specifications.\141\ As 
such, by adopting ABD GVT Revision G for NCAP's AEB testing, NHTSA 
would embrace another opportunity to harmonize with other consumer 
information safety rating programs, as mandated by the BIL. The Agency 
also noted that the ABD GVT would be an appropriate replacement for the 
SSV in NCAP's future AEB testing because the test device (1) afforded 
similar AEB system performance to that of the SSV in comparison 
testing,\142\ and (2) was found to be physically stable and durable 
when evaluated using straight line and curved path maneuvers for 
various speeds and lateral accelerations.\143\ Accordingly, the Agency 
reasoned that the ABD GVT Revision G could be used to evaluate more 
challenging crash scenarios in future NCAP upgrades as well, such as 
those required for other ADAS technologies (intersection safety assist 
(intersection AEB) and Opposing Traffic Safety Assist (OTSA)), which 
would allow harmonization across the program areas. NHTSA did not 
similarly propose adoption of the 4a GVT because it had not yet 
evaluated the in-use characteristics of the device as part of its AEB 
research.
---------------------------------------------------------------------------

    \140\ https://www.euroncap.com/en/for-engineers/supporting-information/technical-bulletins/. See Appendices I & II.
    \141\ Currently, manufacturers use test results from their 
internal testing and submit them to NHTSA for NCAP's recommendation 
of vehicles that pass its performance testing requirements.
    \142\ FCW and CIB onset timings for a given vehicle model were 
found to be highly comparable in the Agency's CIB characterization 
testing regardless of whether the SSV or ABD GVT vehicle test device 
was used. NHTSA notes that ABD GVT Revision E was used for these 
assessments.
    \143\ Snyder, A.C., Forkenbrock, G.J., Davis, I.J., O'Harra, 
B.C., & Schnelle, S.C., A test track comparison of the global 
vehicle target and NHTSA's strikeable surrogate vehicle, (Report No. 
DOT HS 812 698), July 2019, https://rosap.ntl.bts.gov/view/dot/41936.
---------------------------------------------------------------------------

    The Agency, recognizing that there have been ongoing revisions to 
the ABD GVT to address its performance in other crash modes that 
exercise different ADAS applications, proposed to adopt the latest 
revision of the test device, Revision G, for NCAP's AEB testing.

[[Page 95956]]

NHTSA reasoned that this latest revision could be utilized for other 
ADAS technologies proposed for adoption as part of this NCAP upgrade, 
such as blind spot intervention (BSI), as well as future technologies, 
such as intersection safety assist (ISA) and opposing traffic safety 
assist (OTSA). For AEB testing purposes only, NHTSA proposed to accept 
manufacturer verification data for AEB tests conducted using ABD GVT 
Revision F as well. It is the Agency's understanding that modifications 
to the front, side, and oblique aspects of ABD GVT Revision F were 
incorporated into the company's GVT Revision G. NHTSA reasoned that 
these changes should not alter the physical characteristics of the rear 
of the vehicle test device such that a vehicle's performance in the 
rear-end crash mode (i.e., AEB testing) would be impacted.\144\
---------------------------------------------------------------------------

    \144\ To improve the real-world characteristics from the front 
and side of the vehicle test device, several changes to the radar 
treatment were integrated into the components of the body for ABD 
GVT Revision G compared to ABD GVT Revision F, including changes to 
the skin and wheel treatment. There were also some minor shape 
changes to the front of the GVT body to improve front radar return 
and to the side to improve the ability to hold its shape. http://www.dynres.com/2020/02/25/the-new-global-vehicle-target-gvt-has-arrived/.
---------------------------------------------------------------------------

    Though the Agency used ABD GVT Revision E in its comparison testing 
with the SSV, it is unclear if/how the small changes made to Revision E 
to create Revision F may have affected the test track AEB 
performance.\145\ For this reason, NHTSA did not propose to similarly 
accept manufacturer data for AEB test results derived using ABD GVT 
Revision E since this revision is no longer in production. Further, 
NHTSA also did not propose to accept vehicle manufacturer test data 
derived from alternative vehicle test devices other than that which is 
specified in NCAP's test procedures, though this was requested in 
response to NHTSA's November 2015 AEB final decision 
notice.146 147 The Agency explained that during its system 
performance verification testing it has observed several test failures 
that may be attributed to differences in vehicle test device designs. 
Therefore, NHTSA proposed to only accept manufacturer self-reported 
data obtained using tests conducted in accordance with NHTSA test 
procedures.
---------------------------------------------------------------------------

    \145\ It is the Agency's understanding that the modifications 
made to the rear of ABD GVT Revision E consisted of adding 
additional radar-absorbing material to the bottom skirt of the 
vehicle test device to attenuate internal reflections and reducing 
the slope of the simulated rear hatchback glass to increase the 
power of the radar return from the rear aspect.
    \146\ 80 FR 68604 (Nov. 5, 2015).
    \147\ Mercedes-Benz requested that NHTSA consider several 
vehicle test devices and allow manufacturers the option to choose 
which test device is used for testing.
---------------------------------------------------------------------------

    Comments were sought on the adoption of the ABD GVT Revision G in 
lieu of the SSV for AEB testing in NCAP regardless of whether 
modifications were made to test speeds, deceleration, test scenarios, 
combining test procedures, et cetera. The Agency also requested comment 
on whether ABD GVT Revision G was the most appropriate for adoption, 
and whether ABD GVT Revisions F and G should be considered equivalent 
for AEB testing.
Summary of Comments
Use of the ABD GVT Revision G in Lieu of the SSV
    Commenters who supported replacing the SSV with the ABD GVT 
Revision G \148\ in NCAP testing included AAA, Adasky, Auto Innovators, 
BMW, Bosch, CAS, GM, HATCI, Honda, IDIADA, MEMA, Rivian, Subaru, 
Toyota, and ZF Group.
---------------------------------------------------------------------------

    \148\ While not specifically mentioned in most comments, NHTSA 
assumes (unless otherwise indicated) responses to this topic 
pertained to the ABD GVT Revision G, as proposed.
---------------------------------------------------------------------------

    ZF Group stated it supported adoption of the GVT because it was 
developed through coordinated efforts. Several commenters, including ZF 
Group, HATCI, Honda, and GM, stated the GVT more reasonably simulates 
the characteristics (e.g., appearance, camera/radar detection, etc.) of 
actual vehicles. Auto Innovators noted that NHTSA participated in the 
GVT's development and 360-degree correlation to real-world vehicles but 
has yet to adopt it for use in its testing.
    Toyota, GM, and Auto Innovators approved the use of the GVT because 
of its design and inherent durability. The commenters mentioned that 
the GVT is both less susceptible to damage compared to the SSV and less 
likely to induce damage to the SV, which naturally improves test 
efficiency and lowers testing costs. HATCI agreed that the GVT would 
limit damage to the SV and, along with Auto Innovators, asserted that 
it would promote a safer testing environment.
    Intel encouraged NHTSA to adopt the GVT because the Agency showed 
that performance differences between the two vehicle test devices were 
``negligible'' and real-world data has not revealed negative 
consequences due to its use. Furthermore, the company, along with Auto 
Innovators, Rivian, HATCI, Honda, and Adasky, favored the GVT's 
adoption because it would harmonize with Euro NCAP and other consumer 
programs, which Rivian specifically asserted would permit consistency 
in testing and reduce overall test burden and costs. Bosch supported 
adopting the GVT because it is specified in International Organization 
for Standardization Approved Work Item (ISO/AWI) 19206-3:2021.\149\ 
Auto Innovators further added that the GVT would improve repeatability 
for LVD tests. IDIADA suggested that the SSV was ``obsolete,'' and GM 
and Auto Innovators mentioned that it had limited functionality (i.e., 
it is acceptable only for rear-end tests with no offset or angular 
requirements). CAS agreed with the sentiment expressed by these last 
two commenters and asserted that the GVT should replace the SSV because 
it will allow the Agency to perform higher speed tests and additional 
crash scenarios, as well as accommodate testing for other ADAS 
technologies, which will promote more safety.
---------------------------------------------------------------------------

    \149\ ISO/AWI 19206-3:2021, ``Road vehicles--Test devices for 
target vehicles, vulnerable road users and other objects, for 
assessment of active safety functions--Part 3: Requirements for 
passenger vehicle 3D targets.''
---------------------------------------------------------------------------

    DRI mentioned that the GVT should be used in rear-end tests with 
100 percent overlap when closing speeds exceed 40.2 kph (25 mph); 
however, the laboratory asserted that the SSV remains appropriate for 
testing (and offers equivalent results to the GVT) at closing speeds of 
40.2 kph (25 mph) or less. TRC expressed similar sentiments. HATCI also 
recognized the SSV's viability for lower speed rear-end testing but 
argued that since it is limited to low speed rear-end tests, whereas 
the GVT can accommodate higher speeds and additional AEB and other ADAS 
technology test scenarios, the SSV should ideally be replaced with the 
GVT in NHTSA testing. Auto Innovators and GM agreed with HATCI but 
suggested it would be appropriate to ``adopt a phase-in approach'' for 
replacement of the SSV with the GVT since some manufacturers may 
currently be using the SSV for testing. Both Auto Innovators and GM 
suggested that NHTSA accept test data derived using either vehicle test 
device for a period of time.
    In addition to their recommendation that the Agency adopt the GVT, 
Subaru and Auto Innovators requested that NHTSA harmonize with Euro 
NCAP with respect to the GVT moving platform, a GST100/120 or 
4activeFB-Large, manufactured by ABD and 4a, respectively, in addition 
to adopting the related version of the GVT, to limit the cost burden to 
manufacturers.

[[Page 95957]]

Consideration of Other ABD GVT Revisions and Alternative GVTs
    Some commenters supported only adoption of Revision G of the ABD 
GVT at this time, including BMW, Bosch, MEMA, Toyota, and ZF Group. BMW 
recommended use of the ABD GVT Revision G to harmonize with other 
consumer testing programs, including Euro NCAP. As mentioned 
previously, Intel also supported efforts to harmonize where possible. 
IDIADA was another commenter to support using ABD GVT Revision G for 
NCAP's AEB testing. IDIADA opined that ABD GVT Revision G is the 
current standard version and ``offers more stable detection.'' Similar 
to its prior comments for use of the GVT in general, Bosch stated that 
ABD GVT Revision G was appropriate to incorporate because it fulfills 
ISO/AWI 19206-3:2021 requirements; however, the commenter also 
suggested that NHTSA refer to the ISO standard for incorporation rather 
than a GVT revision to allow for more flexibility in market 
participation.
    Several commenters expressed support for ABD GVT Revision G in 
addition to ``lower'' ABD GVT revisions (i.e., E, F) at this time. Auto 
Innovators, CAS, DENSO, DRI, FCA, GM, HATCI, Honda, Subaru, and TRC all 
opined that ABD GVT Revisions F and G should be considered equivalent 
for the purpose of AEB testing covering the current NCAP test 
scenarios. DENSO and Honda (which expressed a preference for ABD GVT 
Revision G) mentioned that since the rear components of both ABD GVT 
Revisions F and G have ``equivalent physical characteristics,'' they 
would be expected to perform the same in scenarios simulating rear-end 
crashes. However, a few of the commenters who supported adopting 
``lower'' ABD GVT revisions for the proposed AEB test matrix, including 
Auto Innovators and GM, remarked that they would recommend use of only 
``higher'' ABD GVT revisions (e.g., ABD GVT Revision G and newer) in 
the future to improve correlation if additional test conditions with 
different approach angles and/or directions are added to Agency 
testing.
    Some commenters, such as GM, supported adoption of ABD GVT Revision 
E in addition to ABD GVT Revisions F and G. Auto Innovators and HATCI 
preferred ABD GVT Revision G but additionally supported the inclusion 
of both ABD GVT Revisions E and F for use in current NHTSA NCAP test 
conditions. HATCI suggested that the Agency allow use of ABD GVT 
Revisions E and F in case of damage or supply shortages. CAS did not 
agree that the Agency should accept data from tests utilizing ABD GVT 
Revision E if that version is ``obsolete'' and ABD GVT Revisions F and 
G are now available.
    Regarding the timeline and preparation for inclusion, HATCI 
requested that manufacturers be given a two-year lead-time to align 
with product development cycles if the Agency was to adopt an 
alternative GVT revision in the future. Auto Innovators requested that 
NHTSA work with other NCAPs to harmonize development of future versions 
of a global vehicle test device suitable for testing.
Response to Comments and Agency Decisions
Use of the ABD GVT Revision G in Lieu of the SSV
    Commenters overwhelmingly supported replacing the SSV with the ABD 
GVT Revision G in NCAP testing, with many echoing points expressed by 
NHTSA in its March 2022 RFC notice. Most notably, commenters stated 
that adoption of the ABD GVT Revision G permits harmonization with 
other consumer information programs, including Euro NCAP, and allows 
the Agency to incorporate higher speed tests and additional test 
scenarios, including those for other ADAS technologies. The ABD GVT 
Revision G is an appropriate surrogate for use in NCAP testing given 
its physical characteristics, material properties, and durability, 
especially when compared to the SSV. The vehicle test device complies 
with ISO/AWI 19206-3:2021, ``Road vehicles--Test devices for target 
vehicles, vulnerable road users and other objects, for assessment of 
active safety functions--Part 3: Requirements for passenger vehicle 3D 
targets'' \150\ with respect to the specifications outlined for radar 
cross section, reflectivity, color, and physical dimensions. As such, 
it is considered to be representative of a real vehicle. Further, in 
the Agency's most recent high-speed AEB research tests, the ABD GVT 
Revision G was found capable of operation at higher speeds and durable 
enough to receive impacts at higher relative speed than possible with 
the SSV. Accordingly, NHTSA plans to use the ABD GVT Revision G to 
conduct NCAP testing to measure the performance of AEB systems 
beginning with model year 2026 vehicles.
---------------------------------------------------------------------------

    \150\ https://www.iso.org/standard/70133.html. May 2021.
---------------------------------------------------------------------------

    Although the Agency did not specify in its RFC notice a specific 
robotic platform to be used with the GVT, a few commenters recommended 
that NHTSA harmonize its platform(s) with Euro NCAP's to decrease 
burden. Because the GVT's movement will be subjected to specifications 
(speed, deceleration magnitude, etc.), the Agency does not see a 
substantial need to specify which platform must be used to achieve the 
appropriate POV kinematics.
Consideration of Other ABD GVT Revisions and Alternative GVTs
    The Agency notes that several commenters favored adoption of ABD 
GVT Revision E and/or F in addition to Revision G, or desired a phase-
in period for adoption of ABD GVT Revision G. Since ABD GVT Revision G 
only includes changes to the front and sides of Revision F, it is 
reasonable to continue to accept data using ABD GVT Revision F for LVS, 
LVD, and LVM AEB test scenarios for a period of time. NHTSA will accept 
manufacturers' AEB self-reported data for tests that use either ABD GVT 
Revisions F or G for the first two model years under the new ADAS 
testing program (i.e., for model year 2026 and model year 2027). For 
model year 2028 and beyond, the Agency will only accept AEB data 
generated using the ABD GVT Revision G vehicle test device. This two-
year period allows sufficient lead-time for vehicle manufacturers to 
procure the required GVT and complete testing for model year 2028 
models. Since the Agency is making extensive changes to the AEB test 
procedures, including integrating FCW evaluations (as will be discussed 
in a later section), no test data collected for model year 2025 
vehicles will carry over to model year 2026. Therefore, it is expected 
that vehicle manufacturers will have to conduct the updated AEB tests 
for all vehicle models in their model year 2026 fleet to claim AEB NCAP 
credit. Although the Agency anticipates that most manufacturers will 
utilize ABD GVT Revision G during testing conducted for their model 
year 2026 models, the Agency recognizes that manufacturers may 
experience procurement delays when obtaining ABD GVT Revision G such 
that only the Revision F version of the test device may be available 
for testing. Therefore, providing a short lead-time to account for this 
possibility is appropriate. For its own testing, NHTSA will utilize ABD 
GVT Revision G to validate AEB system performance beginning with model 
year 2026 vehicles.
    NHTSA has decided it will not accept data obtained from tests 
utilizing ABD GVT Revision E for the 2026 model year and beyond. The 
Agency agrees with CAS that this version should be considered 
``obsolete'' since it is no longer in production. Further, data 
gathered from testing conducted with the SSV will also not be eligible 
for credit starting in model year 2026. As

[[Page 95958]]

mentioned in the March 2022 RFC notice, NHTSA plans to only accept 
self-reported manufacturer data from tests conducted in accordance with 
its test procedures to uphold NCAP's credibility. This requirement 
includes use of the prescribed test device, when applicable. Vehicles 
failing to provide passing performance during the Agency's assessments 
will not receive credit for AEB technology, regardless of whether 
passing results were provided by the vehicle manufacturer in response 
to NCAP's annual data information request.
    Although nearly all commenters supported adoption of Revision G of 
the ABD GVT, the Agency recognizes that Bosch recommended NHTSA 
incorporate by reference ISO/AWI 19206-3:2021 in NCAP, rather than 
stipulate a specific vehicle test device for use in the program's AEB 
tests. The Agency has not conducted thorough evaluations of alternative 
test devices, such as the 4a GVT, to ensure they invoke equivalent 
vehicle/system performance as the ABD GVT Revision G in the Agency's 
AEB tests. Therefore, at this time, the Agency is specifying use of the 
ABD GVT Revision G in the NCAP AEB tests to mitigate variability 
between the Agency's test results and those submitted by the 
manufacturer. As noted earlier, the ABD GVT Revision G meets the ISO 
19206-3:2021 specifications.
Vehicle Test Device Specifications
    Since AEB systems currently on the market may utilize camera-, 
radar-, and/or lidar-based sensors (or some combination thereof) to 
provide automatic emergency braking, the vehicle test device adopted 
for NCAP's AEB testing must meet certain specifications to ensure the 
SV recognizes the target as a real-world vehicle to ensure real-world 
benefit and assure test repeatability and reproducibility. These 
specifications include (1) physical dimensions, such as vehicle width; 
(2) features that are identifiable on the rear of a typical passenger 
vehicle, such as tail lamps, reflex reflectors, windows, and the rear 
license plate; (3) those addressing visual and near infrared 
specifications, such as for the exterior of the vehicle and also for 
various surface features, including tires, windows, and reflex 
reflectors; and (4) radar reflectivity, since many AEB systems rely on 
radar sensors in some capacity to identify the presence of other 
vehicles. Specifications for acceptable vehicle test devices are 
defined in ISO 19206-3:2021, and as mentioned, ABD states that the GVT 
Revision G meets these requirements as manufactured. Given this, it is 
unnecessary to prescribe additional specifications for the ABD GVT 
Revision G for NCAP testing, as compliance with the ISO standard in its 
entirety should be inherent. That said, the Agency will reference ISO 
19206-3:2021 in NCAP's AEB test procedures to ensure any device 
utilized for Agency testing complies with the standard's 
specifications.
h. DBS Brake Application Timing
    The Agency proposed that, should it decide to continue to perform 
DBS testing in NCAP, in lieu of the current procedure of initiating 
manual braking at prescribed TTCs for each test scenario,\151\ brake 
application for all LVD, LVS, and LVM DBS test scenario and speed 
combinations would occur at a time corresponding to 1.0 second after 
the FCW is issued. NHTSA proposed this change would apply regardless of 
whether automatic braking occurs after the FCW but before initiation of 
the manual brake application. The Agency reasoned this procedural 
modification would better represent real-world use and driving 
conditions while also being in basic agreement with the approach 
specified for FCW performance evaluations in Euro NCAP's AEB Car-to-Car 
systems test protocol.\152\ Euro NCAP requires that brake application 
begin 1.2 seconds after issuance of the FCW. As an alternative to this 
proposal, NHTSA also requested comment on appropriate TTCs for the 
modified test conditions.
---------------------------------------------------------------------------

    \151\ The TTCs prescribed for actuator braking in NCAP's DBS 
test procedure are 1.1 seconds, 1.0 second, and 1.4 seconds, 
respectively, for the LVS, LVM, and LVD scenarios.
    \152\ European New Car Assessment Programme (Euro NCAP) 
(November 2022), Test Protocol--AEB Car-to-Car systems, Version 
4.1.1. See Annex A.
---------------------------------------------------------------------------

Summary of Comments
    Many commenters, including Toyota, Honda, GM, and Tesla, agreed 
with the Agency's proposal to trigger manual brake application 1.0 
second after the FCW is issued in DBS testing. GM supported the 
proposed changes for the Agency's DBS test procedure, stating that such 
modifications would better align with protocols used by other NCAPs and 
``provide a more comprehensive assessment of overall system 
performance.'' GM, Honda, and ZF Group commented that the proposed time 
of 1.0 second after issuance of an FCW would reasonably simulate the 
time it might take a driver to depress the vehicle's brake after an FCW 
is issued. Tesla agreed that this was a reasonable method of 
replicating human behavior but cautioned the Agency to use factory 
default settings for configurable FCW timing settings to ensure 
consistency across vehicle models.
    Auto Innovators, Bosch, IDIADA, and Intel agreed with the Agency's 
proposal of applying the brake 1.0 second after the FCW was issued in 
DBS tests but suggested that a brake application timing of 1.2 seconds 
after the FCW, as used by Euro NCAP, would also be reasonable. Like 
other commenters, Auto Innovators stated that triggering a brake 
application at a prescribed time after issuance of an FCW in the 
Agency's DBS tests rather than at a fixed TTC is more appropriate since 
the intent of an FCW is to compel the driver to react; thus, it should 
be more representative of the driver's behavior under real-world 
conditions. The group added that aligning with Euro NCAP's brake 
activation timing would reduce test burden.
    Rivian stated the Agency should adopt a ``lower time gap'' between 
the FCW and manual brake application because CIB will often activate 
and move the brake pedal before DBS activation, (as the Agency 
acknowledged in its 2022 RFC notice), such that not all DBS systems may 
be effectively assessed if the Agency were to adopt the proposed test 
procedure modifications. Similarly, in agreement with its 
recommendation to conduct integrated assessments for FCW, CIB, and DBS 
collectively ``to better assess the total safety benefit,'' BMW stated 
that once CIB activates, ``any DBS influence is irrelevant.''
    CAS recommended that the Agency should base brake application 
timing for DBS testing on actual human driver responses to an FCW.
Response to Comments and Agency Decisions
    To provide a comprehensive assessment of AEB system performance, 
the Agency has decided to initiate manual (robotic) brake application 
in NCAP's LVS, LVD, and LVM DBS tests at a time that corresponds to 1.0 
 0.1 seconds after issuance of the required FCW signals 
(i.e., both signals for any bimodal warning, as will be discussed 
later) instead of at prescribed TTCs, as is done currently. The 
prescribed 1.0-second delay is based on the time it takes a driver to 
react when presented with an obstacle.\153\ If the FCW (i.e., one or 
more of the required two signals) is not issued in an LVS, LVD, or LVM 
DBS

[[Page 95959]]

test, the SV accelerator pedal will not be released, and the brake will 
not be manually applied prior to impact with the vehicle test device 
(i.e., POV).\154\ This planned procedural change will not apply to the 
false positive DBS assessment since an FCW is not expected during this 
assessment (though it may occur). For the false positive DBS test, the 
SV brakes will be applied (after throttle release) \155\ at a TTC of 
1.1 seconds, corresponding to a nominal distance of 24.4 m (80.2 ft.) 
from the edge of the STP.
---------------------------------------------------------------------------

    \153\ Fitch, G.M., Blanco, M., Morgan, J.F., Rice, J.C., 
Wharton, A., Wierwille, W.W., & Hanowski, R.J. (2010, April) Human 
Performance Evaluation of Light Vehicle Brake Assist Systems: Final 
Report (Report No. DOT HS 811 251) Washington, DC: National Highway 
Traffic Safety Administration, p. 101.
    \154\ In this instance, the vehicle will also fail the trial 
run.
    \155\ For the false positive DBS tests, the subject vehicle 
accelerator pedal will be released at any rate, such that it is 
fully released within 500 milliseconds, either when a forward 
collision warning is given or at a headway that corresponds to a 
time-to-collision of 2.1 seconds, whichever occurs earlier.
---------------------------------------------------------------------------

    NHTSA notes that commenters were generally supportive of this 
proposed change and agreed that such an approach better represents 
human behavior during real-world driving. Several respondents also 
noted this approach aligns well with Euro NCAP's AEB Car-to-Car systems 
test protocol, which specifies that braking is applied 1.2 seconds 
after the FCW is issued. Though some commenters requested that the 
Agency harmonize precisely with Euro NCAP's specification, the Agency's 
requirement is reasonable, and NHTSA has no data showing that a 
reaction time of 1.2 seconds is more appropriate. Previous NHTSA 
research has shown it takes drivers 1.04 seconds, on average, to begin 
applying the brake when presented with an unexpected obstacle, and 0.8 
seconds when presented with an anticipated obstacle.\156\ For similar 
reasons, NHTSA reasons it is inappropriate to adopt a lower time gap 
between the FCW and manual brake application, as requested by Rivian.
---------------------------------------------------------------------------

    \156\ Fitch, G.M., Blanco, M., Morgan, J.F., Rice, J.C., 
Wharton, A., Wierwille, W.W., & Hanowski, R.J. (2010, April) Human 
Performance Evaluation of Light Vehicle Brake Assist Systems: Final 
Report (Report No. DOT HS 811 251) Washington, DC: National Highway 
Traffic Safety Administration, p. 101.
---------------------------------------------------------------------------

    Regarding Rivian's concern that CIB may activate and move the brake 
pedal after the time of the FCW but before the brake pedal is manually 
applied one second later during DBS testing, the Agency has observed 
this phenomenon and does not consider it problematic for several 
reasons. First, although the presence of CIB braking may negate the 
need for DBS activation (i.e., the supplemental braking typically 
associated with DBS is not required since the CIB system may already be 
braking the vehicle at its maximum capability), the manual brake 
application timing relative to the FCW is not changed and the crash 
avoidance performance requirement remains in place, so the test 
severity is fully retained. Second, tests where the brakes are manually 
applied after a CIB intervention has been initiated provide an 
opportunity not only to demonstrate the vehicle can avoid the POV, but 
also to ensure that the driver's input does not override the CIB system 
such that it reverts to the braking level input by the driver alone 
(i.e., without any braking contribution from AEB), since doing so would 
be expected to result in contact with the POV, and therefore a test 
failure. Third, the Agency defines the onset of SV manual brake 
application as when the force applied to the brake pedal is >=11 N (2.5 
lbf), not when the brake pedal physically moves. This is a 
consideration for both CIB and DBS tests when assessing whether a given 
test trial is valid (i.e., performed properly). For CIB testing, the 
Agency's test procedure prohibits the driver from applying force to the 
brake pedal during the test's validity period. For DBS testing, the 
onset of SV manual braking is important when assessing manual brake 
application timing relative to the onset of the FCW.
    Given the Agency's decision to initiate manual (robotic) brake 
application in NCAP's LVD, LVS, and LVM DBS tests at a time that 
corresponds to 1.0  0.1 seconds after issuance of the 
required FCW signals, the Agency has also tried to limit the effect of 
different FCW timing settings (e.g., early vs. late) on AEB testing 
outcomes to best ensure consistency across vehicle models, as Tesla 
suggested. As discussed later in this final notice, NHTSA has decided 
to specify use of the middle (or next latest) FCW setting in lieu of 
the default setting (as Tesla requested) or the latest alert setting 
for NCAP testing. This is because the warning setting most preferred by 
drivers will likely correspond to the default setting and should 
generally fall in the middle of the range of driver setting preferences 
that span either earlier or later alert settings.
i. SV Throttle and Brake Application Overlap in DBS Tests
    The Agency's existing DBS test procedure states that the 
accelerator pedal must be fully released within 500 ms after an FCW is 
issued but prior to the onset of the manual SV brake application by a 
robotic brake controller, a timing currently dictated in the test 
procedure (as prescribed TTCs) for each test condition. As mentioned 
previously, if the Agency decided to continue to perform DBS testing in 
NCAP, it proposed to revise the time when the manual (robotic) brake 
application is initiated during testing to a time that corresponds to 
1.0 second after the FCW is issued, even in instances where automatic 
braking (i.e., CIB) occurs after the FCW but before initiation of the 
manual brake application. However, as an alternative to this proposed 
procedural change, NHTSA also requested comment on appropriate revised 
TTCs for the modified DBS test conditions. In the event the Agency 
decided to proceed with this alternative proposal to adopt revised 
TTCs, NHTSA proposed that the current test specifications for pedal 
release timing (i.e., within 500 ms after an FCW is issued, but prior 
to the onset of the prescribed manual SV brake application by a robotic 
brake controller) would be maintained.
    In its March 2022 RFC notice, the Agency recognized that the 
current test requirements for pedal release timing can be problematic 
if no FCW is issued or if the alert happens very close to the 
prescribed brake activation timing, because the throttle may still be 
depressed (since no warning was issued, or it was issued late) while 
the SV brakes are applied by the robot at the prescribed TTC. The 
Agency documented this possibility (i.e., where the SV throttle and 
brake pedals are applied at the same time) during track testing and 
provided a recommendation that up to a 250 ms overlap be allowed.\157\ 
In other words, once the SV driver detects that the robot has applied 
the brakes, the driver will have 250 ms (instead of 500 ms) to fully 
release the accelerator. A test run would not be valid unless this 
criterion is met.
---------------------------------------------------------------------------

    \157\ Forkenbrock, G.J., & Snyder, A.S. (2015, June), NHTSA's 
2014 automatic emergency braking test track evaluations (Report No. 
DOT HS 812 166), Washington, DC: National Highway Traffic Safety 
Administration.
---------------------------------------------------------------------------

    Given the Agency's findings and recommendation, NHTSA sought 
comment on whether it would be acceptable to modify NCAP's DBS test 
procedure (in the event it adopted revised TTCs for the modified DBS 
test conditions) to allow a 250 ms overlap of SV throttle and brake 
pedal application in instances where no FCW has been issued by the 
prescribed TTC in a DBS test, or where the FCW is issued very close to 
brake activation.
Summary of Comments
    Several commenters, including Auto Innovators, FCA, GM, and Rivian, 
stated that a 250 ms overlap for SV throttle and brake pedal 
application was acceptable. Rivian added that it appropriately

[[Page 95960]]

simulates panic braking within 250 ms of an FCW in real-world driving 
situations. Honda also agreed that such an overlap was unobjectionable 
``as long as the application of SV throttle is not excessive'' since 
this could possibly affect braking performance.
    In contrast, IDIADA and Intel did not support any amount of 
throttle and brake overlap. IDIADA commented that the DBS test 
procedure is intended to simulate a driver's normal response in 
situations represented by the test scenarios. As such, the laboratory 
asserted there should be no overlap between brake and throttle 
application since the driver would normally be operating both pedals 
with one foot, and therefore could not depress both simultaneously. 
Intel expressed a similar sentiment.
    TRC noted that, as not all throttle robots permit application of 
both the brake and throttle at once, some test entities may have to 
purchase new equipment if NHTSA was to adopt this test procedural 
change.
Response to Comments and Agency Decisions
    NHTSA has decided not to adopt a 250 ms overlap for testing 
scenarios, despite several commenters stating that such an overlap is 
acceptable. The 250 ms overlap is unnecessary because it has 
implemented requirements in NCAP's LVD, LVS, and LVM DBS tests to (1) 
fully release the SV's accelerator pedal (at any rate) within 500 ms 
after an FCW is issued (whether it be before or after automatic braking 
has begun), and (2) initiate manual (robotic) brake application at a 
time that corresponds to 1.0  0.1 seconds after issuance of 
the required FCW signals (i.e., any dual-modality alert, as discussed 
later) instead of at currently prescribed TTCs.
    In any situation, the throttle should be fully released for a 
minimum of 500 ms prior to manual brake application. This manual 
(robotic) braking procedure aligns with comments received from IDIADA 
and Intel, both of which stated it was inappropriate for throttle 
depression to overlap with brake application. The Agency agrees with 
IDIADA that NCAP's DBS test procedure should simulate real-world 
driving conditions, where the driver's foot would be removed from the 
throttle prior to depressing the brake. The changes NHTSA has made to 
throttle release and robotic brake application timing requirements 
reflect that intention.
    NHTSA also asserts the possibility of SV throttle and brake 
application overlap does not exist for the false positive DBS 
assessment. In the false positive DBS test, issuance of an FCW is not 
expected (though it may occur). As such, the SV throttle is to be 
released within 500 ms of the prescribed TTC (2.1 seconds) if no FCW is 
issued by the specified time. If an FCW is issued, the SV throttle is 
released within 500 ms of the warning. In both situations, the SV 
brakes are then to be applied at a TTC of 1.1 s, which corresponds to a 
nominal distance of 24.4 m (80.2 ft.) from the edge of the STP. Like 
the LVD, LVS, and LVM DBS tests, the SV accelerator should always be 
fully released for a minimum of 500 ms prior to brake application in 
the false positive DBS test, regardless of whether an FCW is issued. 
NHTSA notes that no commenters suggested revised TTCs for the false 
positive test condition. As such, the Agency will maintain the current 
TTC requirement for the 80 kph (49.7 mph) false positive test 
condition. This is reasonable given the same TTC requirements are 
currently specified for both the 40.2 kph (25 mph) and 72.4 kph (45 
mph) test speeds.
    Finally, TRC's contention that some braking robots are not able to 
apply both the brake and accelerate at the same time is no longer a 
concern, because overlap between the SV throttle and manual brake 
application is now avoidable for all DBS tests due to the adopted 
throttle release and brake application timing requirements.
j. Addition of Manual Brake Application Controller Option
    To achieve accurate, repeatable, and reproducible SV brake pedal 
inputs during NCAP's DBS tests, NHTSA uses a programmable brake 
controller, set to one of two closed-loop control modes--constant pedal 
displacement or hybrid feedback--to command the necessary brake 
force.\158\
---------------------------------------------------------------------------

    \158\ National Highway Traffic Safety Administration (2015, 
October), Dynamic brake support performance evaluation confirmation 
test for the New Car Assessment Program, http://www.regulations.gov, 
Docket No. NHTSA-2015-0006-0026.
---------------------------------------------------------------------------

    The Agency is incorporating a third manual brake application 
controller option, a force-only feedback controller, which will provide 
another useful method of brake application. The force feedback 
controller is substantially similar to the hybrid controller with the 
commanded brake pedal position omitted, leaving only the commanded 
brake pedal force application.
    For the force feedback procedure, the commanded brake pedal 
application is the brake pedal force that results in a mean 
deceleration of 0.4g in the absence of AEB system activation. The mean 
deceleration is the deceleration over the time from when the commanded 
brake pedal force is first achieved to 250 ms before the vehicle comes 
to a stop. The force controller applies a force of at least 11.1 N (at 
an unrestricted rate) to the brake pedal to achieve the commanded brake 
pedal force within 250 ms. The force controller may overshoot the 
commanded force by any amount up to 20 percent. If such an overshoot 
occurs, it must be corrected within 250 ms from when the commanded 
force is first achieved. The average pedal force must be maintained 
within 10 percent of the commanded brake pedal force from 250 ms after 
the commanded pedal force occurs until test completion.
k. Regenerative Braking
    In its March 2022 RFC notice, the Agency noted that regenerative 
braking \159\ may influence vehicle performance during its AEB tests 
and create complications for DBS testing.
---------------------------------------------------------------------------

    \159\ Regenerative braking slows a vehicle down when the 
accelerator pedal is released, which helps traditional brakes. It 
also recovers kinetic energy that would otherwise turn into heat by 
converting it into electrical energy for storage in onboard 
propulsion batteries. Regenerative braking is a common feature in 
electric-powered vehicles.
---------------------------------------------------------------------------

    Regenerative braking, which has become more common as electric 
vehicles have begun to proliferate the fleet, slows a vehicle when the 
accelerator pedal is released. As such, a vehicle that has regenerative 
braking may exhibit a significant speed reduction prior to the onset of 
AEB-induced braking during the Agency's CIB and DBS testing, 
particularly in instances where the FCW is issued early, since the 
vehicle's accelerator pedal is to be fully released upon the issuance 
of the FCW. Furthermore, a relatively high deceleration resulting from 
regenerative braking can introduce complications during DBS testing, as 
only a relatively small increase in braking from the braking actuator 
would be required to provide the necessary combined 0.4g 
deceleration.\160\
---------------------------------------------------------------------------

    \160\ For instance, if the regenerative braking from simply 
releasing the accelerator pedal results in 0.3g braking, the 
additional braking required from the actuator to achieve a total 
deceleration of 0.4g would be a very low force and/or brake pedal 
displacement.
---------------------------------------------------------------------------

    To limit the influence of regenerative braking during AEB testing, 
NHTSA proposed to select the ``off'' setting, or the setting that 
provides the lowest deceleration when the accelerator is fully released 
for those vehicles offering multiple regenerative braking settings 
(e.g., less aggressive, nominal, more aggressive). The Agency proposed 
to test with the least aggressive setting (or the ``off'' setting) over 
the ``nominal'' setting for two reasons. First, NHTSA believed

[[Page 95961]]

that the least aggressive (or ``off'') regenerative braking setting 
would be the setting most likely to produce comparable performance to 
vehicles that are not equipped with a regenerative braking feature. 
Second, the Agency reasoned that the least aggressive setting would 
likely afford ``worst case'' performance during testing, since it 
should generate the lowest deceleration and thus allow the vehicle to 
travel faster at the onset of AEB braking. The Agency did not propose 
to make any procedural modifications for vehicles that have 
regenerative braking that cannot be switched off or adjusted, since 
those vehicles should operate similarly during testing as compared to 
real-world driving.
    Comments were requested on whether the proposed setting selection 
was appropriate. NHTSA also requested comment on whether regenerative 
braking could introduce additional testing issues for the Agency's AEB 
testing, such as those described, along with recommendations for test 
procedural changes to best address them.
Summary of Comments
    Most commenters agreed with the Agency's proposal to select the 
``off'' setting during AEB NCAP testing. However, a few respondents 
favored the ``Default'' setting or letting manufacturers choose the 
setting they preferred.
Choose ``Off'' or the Lowest Setting
    Commenters who favored turning regenerative braking ``off'' and/or 
selecting the lowest regenerative braking setting for AEB testing 
included Advocates, BMW, CAS, FCA, GM, Honda, Intel, and TRC. Intel 
commented that choosing the regenerative braking setting that is 
considered ``worst case'' (i.e., ``off'') is ``reasonable,'' while CAS 
remarked that NHTSA should evaluate ADAS systems in ``the least 
favorable foreseeable circumstances.'' GM remarked that it was most 
appropriate to conduct a worst-case performance assessment for electric 
vehicles (i.e., regenerative braking ``off'') since it is currently 
unknown what percentage of drivers release the accelerator pedal prior 
to, or during, AEB activation (such that regenerative braking would 
engage). BMW asserted that selecting the ``off'' or lowest setting for 
regenerative braking is appropriate because choosing a setting that 
induces high regenerative braking may unfairly skew AEB test results. 
Advocates agreed that the regenerative braking setting should be set to 
``off'' unless there is no way to disable it, and Honda commented that 
NHTSA's approach seems ``reasonable for most vehicles'' for AEB and FCW 
assessments.
    A few commenters favored the ``off'' or lowest setting for 
regenerative braking because alternative settings may cause 
complications for testing. TRC and GM mentioned that the ``off'' or 
lowest settings simplify test execution. TRC added that they have seen 
instances where a test cannot be properly conducted per the applicable 
procedure to create a crash-imminent situation because of early FCWs 
coupled with high regenerative braking. FCA noted that disabling 
regenerative braking improves test repeatability, particularly for DBS 
tests, due to ``different brake pedal behavior when transitioning from 
regeneration to braking.'' For this reason, the automaker recommended 
that the Agency select the ``off'' setting in the near-term and switch 
to an alternative setting (resulting in a ``more complicated test'') if 
real-world data supports this change. GM agreed that selecting the 
``off'' setting for regenerative braking would lead to more consistent 
testing for electric vehicles.
Choose the ``Default'' Setting
    In lieu of turning regenerative braking ``off'' or to the lowest 
setting for AEB testing, Rivian, Tesla, and HATCI stated that NHTSA 
should use the factory default setting, as this setting is more 
consistent with real-world driving. HATCI commented that an internal 
study of Hyundai and Kia owners revealed that most owners do not change 
the ADAS settings from the factory default settings after purchasing a 
vehicle.\161\ As such, the commenter stated the Agency should only 
deviate from default settings for testing purposes if there is a need 
to do so to ensure safe test conduct. Given these findings for ADAS 
settings, HATCI encouraged NHTSA to conduct a similar fleet-wide study 
of customer-selected regenerative braking settings before incorporating 
related test procedure changes. Similarly, Tesla mentioned that the 
company's fleet data has shown that over 80 percent of Tesla vehicles 
on the road use the default setting for regenerative braking. Like 
other commenters above, the manufacturer acknowledged that different 
regenerative braking settings will generate different AEB performance. 
Similar to TRC, Tesla mentioned that, depending on the regenerative 
braking setting selected, a vehicle may not even need to activate AEB 
in some test scenarios because regenerative braking effectively slows 
the vehicle to a stop and prevents it from making contact with the 
vehicle test device.
---------------------------------------------------------------------------

    \161\ https://www.regulations.gov/comment/NHTSA-2021-0002-3862. 
HATCI's internal research covered nine focus groups of Hyundai and 
Kia vehicle owners from 2017-2019 from the Chicago, IL area (N=24) 
and an online survey.
---------------------------------------------------------------------------

Let Manufacturers Specify the Setting
    Auto Innovators explained that they were not opposed to turning 
regenerative braking ``off'' for electric vehicles but requested that 
NHTSA allow vehicle manufacturers to specify the regenerative braking 
setting they want to be tested (``off'' or otherwise) for each vehicle/
test.
Single-Pedal Operation Considerations
    Honda and Auto Innovators requested that NHTSA amend the AEB test 
procedures, where appropriate for electric vehicles, to clarify what it 
means for the throttle to be ``fully released'' in vehicles that use 
one pedal for both acceleration and braking. To accommodate vehicles 
using one pedal operation, the commenters suggested that ``fully 
released'' should translate to ``an accelerator position that provides 
deceleration equivalent to that of engine braking, about 0 to 0.1 g.'' 
BMW expressed a similar sentiment.
Response to Comments and Agency Decisions
    NHTSA has decided that, for NCAP's AEB tests, it will adopt its 
initial proposal to select the ``off'' setting for regenerative 
braking, or the setting that provides the lowest deceleration when the 
accelerator is fully released for those vehicles offering multiple 
regenerative braking settings (e.g., less aggressive, nominal, more 
aggressive). Although some commenters shared the assertion that this 
setting is not reflective of real-world use, it is prudent to perform 
testing to represent the worst reasonable case scenario, a sentiment 
shared by multiple respondents. By taking such an approach, the 
vehicle's speed just prior to either manual (robotic) or automatic 
braking will be retained to the greatest extent possible, which should 
allow the Agency to most objectively evaluate the vehicle's ability to 
avoid a crash without introducing confounding factors caused by early 
FCWs or significant braking prior to the onset of AEB. In a similar 
vein, selecting the ``off,'' or least aggressive regenerative braking 
setting, should improve test execution, and thus test repeatability, 
and allow the Agency to evaluate actual system performance more 
effectively, as several commenters mentioned. Also, selecting the 
``off'' setting promotes a level of fairness. This is particularly 
important for a consumer information program in which comparisons may 
be made between

[[Page 95962]]

vehicle model test results. If the Agency instead allowed vehicle 
manufacturers to specify any regenerative braking setting that they 
prefer, as Auto Innovators suggested, this could result in AEB 
performance that is not comparable to other tested vehicles in the 
fleet, and thus, not necessarily consistent in a way consumers might 
expect.
    With respect to accelerator pedal input and release for vehicles 
equipped with a one pedal operation mode, by setting regenerative 
braking to ``off,'' one pedal operation will also effectively be 
disabled in most instances. However, in agreement with the decision 
made above to select settings that provide the lowest deceleration in 
order to represent the worst reasonable case scenario, the Agency will 
also select the ``off'' setting for one pedal operation, for those 
vehicles offering selectable settings for modes of operation. If one 
pedal operation cannot be disabled (i.e., regenerative braking is 
always enabled and one pedal operation cannot be switched ``off''), the 
vehicle will be tested with the moderate deceleration level ensuing 
from accelerator pedal release. At this time, accelerator pedal release 
need not be defined beyond the definition applicable to vehicles that 
do not permit one pedal operation. The Agency will require the 
accelerator pedal to be fully released within 500 ms after the FCW is 
presented for all vehicles, including those equipped with a one pedal 
operation mode.
    For electric vehicles, propulsion batteries will be charged at 80 
percent or higher capacity during NCAP's AEB testing. This decision 
aligns well with the Agency's decision to select the setting for 
regenerative braking that provides the lower deceleration when the 
accelerator is fully released. Performing AEB assessments with a higher 
SOC should limit regenerative braking.
l. Refinement and Clarification of Test Procedures
    In addition to the changes discussed herein for NCAP's AEB test 
procedures, the Agency also sought public comment on whether there are 
any aspects of NCAP's current FCW, CIB, and/or DBS test procedure(s) 
that need further refinement or clarification. Commenters responded 
with recommendations for general test procedure clarifications, 
additions, and refinements. These recommendations tended to fall into 
three general categories: the use of robotic test equipment, tolerances 
currently used, and general test procedure changes to either increase 
the applicability of results or to increase repeatability.
Summary of Comments
Robotic Test Equipment
    Auto Innovators requested that driver braking be implemented in a 
``more realistic manner.'' The group asserted that, in general, a brake 
robot ``adds a degree of reliability to the test operation.'' 
Accordingly, the organization suggested that the Agency eliminate human 
operation to the extent possible for all AEB tests and specify use of a 
robot-controlled POV test device. Toyota also asserted that the Agency 
should require the SV to be controlled by a steering robot controller 
since vehicle test devices can be controlled by a GST system.
    GM and Auto Innovators requested that NHTSA harmonize the robotic 
test equipment and settings used in NCAP's tests with other equipment 
used by industry and other NCAPs globally. However, at a minimum, Auto 
Innovators requested NHTSA refine the brake robot procedure to add more 
detailed instructions about calibration and setup. Both commenters 
mentioned that one of NHTSA's test contractors uses different robotic 
test equipment than that which is commonly used, and the robot 
parameters are applied slightly differently in NCAP's tests. Per GM, 
troubleshooting performance issues may be difficult when differences 
arise because of various equipment and settings.
    TRC asked for NHTSA to clarify the meaning of the test procedure 
phrase ``smooth throttle inputs.'' The commenter mentioned that data 
from brake and throttle robots, which are helpful to maintain speed 
tolerances, may appear ``noisy'' even with tuning. As such, they 
requested clarification on NHTSA's definition of ``smooth'' in such 
instances. Auto Innovators requested that accelerator pedal release 
rates be defined in general.
    IDIADA noted that regenerative braking may affect the speed control 
during testing when regenerative braking is activated, such that the 
throttle robot may ``over-throttle and result in an override action.'' 
To prevent the occurrence of a system override, the commenter suggested 
that NHTSA ``ensure that [the] throttle robot is kept on [the] hold 
position prior to AEB activation.''
Changes to Tolerances
    Honda and Auto Innovators asserted that the tolerances for POV and 
SV deceleration, POV and SV speed, and headways in the Agency's CIB and 
DBS test procedures are currently too wide. The commenters noted the 
combined tolerance variation ``have a significant influence on 
collision closing speed and timing,'' and Honda added that certain 
tolerance combinations can prevent a possible SV and POV collision. As 
such, both commenters recommended that NHTSA adopt the tolerances Euro 
NCAP uses for these test variables to (as Honda stated) improve test 
objectivity and uphold program credibility.\162\ Toyota also 
recommended that NHTSA adopt Euro NCAP tolerances if the Agency 
ultimately decides to incorporate higher test speeds and higher 
decelerations for the lead vehicle with shorter headways. Toyota 
asserted that if test procedures allow for wide variation, then system 
design will need to cover the variation, potentially causing real-world 
false positive cases to increase. Intel suggested certain tolerances 
should be tightened, noting that if the headway and braking force of 
the braking robot are at the higher end of the tolerance range, ``the 
brake robot itself is almost enough to avoid the collision,'' making it 
difficult to assess what is supposed to be a crash-imminent event.
---------------------------------------------------------------------------

    \162\ See Appendix A of Honda's submission for detailed proposed 
revisions.
---------------------------------------------------------------------------

General Test Procedure Additions/Clarifications
    To improve test repeatability and reproducibility, Tesla suggested 
NHTSA should better define the ``end-of-the-event'' in the test 
procedures.
    Additionally, CAS suggested that the Agency should conduct testing 
to ensure vehicles provide effective warnings when ``safe operating 
limits are exceeded,'' such as for certain environmental conditions 
(e.g., ice, snow), maximum speed conditions for ADAS operation, or upon 
violation of minimum following distances.
Response to Comments and Agency Decisions
Robotic Test Equipment
    Proper test conduct is vital to the credibility of NCAP, and the 
Agency seeks to maximize testing consistency wherever possible. NHTSA 
agrees with commenters that eliminating human operation as much as is 
practicable might be helpful in maintaining test repeatability. 
However, NCAP CIB and DBS testing currently utilizes a human driver to 
maintain SV lane position and speed, and NHTSA has not encountered 
problems with achieving valid tests using human inputs to satisfy the 
test tolerances associated with these parameters. Therefore, NHTSA is 
not

[[Page 95963]]

requiring robotic control of all SV inputs used to perform the Agency's 
AEB tests. However, there are some inputs where robotic control is 
beneficial, namely those associated with the SV brake pedal inputs 
(e.g., force, velocity, and displacement) used during DBS testing. For 
instance, the test tolerances associated with these inputs must be 
accurately achieved and maintained throughout the brake application. 
Also, some vehicles require a precise transition from brake pedal 
inputs based on position control to those based on applied force. Such 
brake inputs are difficult to reproduce with a human driver. In the 
future, NHTSA may consider performing AEB tests using robotic control 
of all SV inputs.
    Along these lines, NHTSA will not harmonize the robotic test 
equipment and/or settings used with those used commonly in industry. 
The Agency has specified steering, throttle, and brake input 
requirements that must be met. Therefore, it is not warranted to 
specify particular equipment.
    With respect to the POV, the Agency's decision to use the ABD GVT 
Revision G during NCAP's AEB tests necessarily requires that the test 
device be secured to a robotic platform to facilitate movement during 
conduct of the LVM and LVD tests. For the sake of scenario-to-scenario 
consistency, the ABD GVT Revision G will also be secured to an LPRV 
during conduct of the LVS tests. NHTSA notes that the movement of a 
robotic platform is accurately and repeatably controlled and can be 
safely achieved, monitored, and terminated, if necessary, by laboratory 
personnel at any time during a test trial. Given the demanding test 
conditions of the CIB and DBS tests described in this notice, these are 
all important considerations.
    NHTSA received general comments regarding throttle and brake 
inputs. Pertaining to the test procedure phrase ``smooth throttle 
inputs,'' there is no current definition of this phrase. The intent 
underlying this description is that the manner in which the accelerator 
pedal inputs are applied must not confound AEB operation or affect the 
test outcome. As described in the previous section, further definition 
of accelerator pedal release rates, as Auto Innovators requested, is 
unnecessary. Finally, NHTSA has not encountered the over-throttling 
problem that IDIADA has described; therefore, no changes will be made 
to the test procedure at this time to alter throttle robot inputs. 
However, the Agency will make refinements to the procedures in the 
future to clarify additional details if the need arises.
Changes to Tolerances
    NHTSA acknowledges that several commenters to the March 2022 RFC 
notice reasoned that many tolerances in the Agency's CIB and DBS test 
procedures should be revised. Specifically, commenters remarked that 
tolerances were too wide. Honda noted that wide tolerances in NHTSA's 
DBS LVD test procedure may compound and allow for a vehicle with 
borderline performance to either make contact or not, depending on test 
parameters. NHTSA does not expect Honda's concern to be relevant for 
the updated NCAP AEB tests. Specifically, the wide assortment of test 
conditions being evaluated (e.g., POV speed combinations, SV-to-POV 
headways and POV decelerations (for LVD tests)), along with a no-
contact criterion, contributes to greater test stringency overall. A 
vehicle achieving marginal performance will likely have difficulty 
passing the suite of tests performed by NCAP. Further, the Agency's 
current test tolerances balance the desire to perform the tests as 
accurately and consistently as possible with the ability to practically 
perform them. NHTSA has demonstrated the practicability of using its 
AEB test tolerances during NCAP and research testing; thus, it is 
appropriate to retain their use during conduct of the updated NCAP CIB 
and DBS tests.
    Regarding comments on SV speed, NHTSA's experience is that test 
vehicle speed can be reliably controlled within the proposed tolerance, 
and that speed variation within the tolerance yields consistent 
results. A smaller speed tolerance would be unnecessarily burdensome, 
as it may result in a higher rate of invalid test runs without any 
greater assurance of test accuracy. Therefore, the Agency will proceed 
with a speed tolerance of 1.6 kph (1.0 mph) for 
both the SV as well as for the POV in NCAP's CIB and DBS testing.
General Test Procedure Additions/Clarifications
    Regarding comments relating to the definition of the end of the 
validity or test period, for the AEB LVS and LVD scenarios, NHTSA 
considers a test run complete when either of the following occurs: (1) 
the SV contacts the POV; or (2) the SV comes to a complete stop without 
making contact with the POV. For the AEB LVM test scenario, a test run 
is considered complete when either of the following occurs: (1) the SV 
contacts the POV; or (2) the SV speed becomes less than or equal to the 
POV speed without contacting the POV. For the false positive STP test, 
the test is complete when either (1) the SV comes to a stop prior to 
crossing over the leading edge of the steel trench plate, or (2) when 
the frontmost part of the SV crosses over the leading edge of the STP.
    NHTSA acknowledges that some vehicles are equipped with telltales 
that alert the driver that an ADAS system is not functional. These 
cases may include manual system deactivation or detection of system 
malfunction, which may result from sensor obstruction or saturation due 
to accumulated snow or debris, sunlight glare, fog, and other 
environmental conditions. These warnings serve as an indication to the 
driver that assistance with the driving task is not available. While 
NHTSA agrees that these warnings are useful to the driver, stipulating 
the type, function, and performance of a system malfunction warning is 
out of scope of an NCAP evaluation and is more suitable for rulemaking.
2. FCW
a. NHTSA's Proposal for FCW Testing, Including Alternatives
    NCAP's current FCW requirements were developed at a time when FCW 
and AEB functionality were not integrated as part of one frontal crash 
prevention system. Consequently, when FCW was selected for inclusion in 
the program in 2008, the Agency adopted a test procedure and 
performance requirements that served only to evaluate the performance 
of FCW systems. However, in recent years, there has been a shift 
towards FCW and AEB system integration to improve real-world safety 
performance and consumer acceptance. It may be reasonable to combine 
FCW testing with AEB (and PAEB) testing such that FCW operation is 
evaluated as part of NCAP's AEB (and PAEB) tests. NHTSA also expects 
this change would reduce test burden since there will not be an 
additional suite of tests to conduct solely for the purpose of 
verifying FCW performance.
NHTSA's Proposal for FCW Testing--Integrating FCW Assessments Into CIB 
Testing
    In its March 2022 RFC Notice, NHTSA proposed that the Agency's CIB 
(and PAEB) tests could be used as an indicant of FCW functionality. 
Essentially, the Agency would evaluate the functionality of a vehicle's 
FCW system during the CIB system evaluation by requiring the SV's 
accelerator pedal to be fully released within 500 ms after the FCW is 
issued. If no FCW were issued during a CIB test, the SV accelerator 
pedal would be fully released within 500 ms after the onset

[[Page 95964]]

of CIB system braking (as defined in the Agency's proposal as the 
instant SV deceleration reached at least 0.5g).\163\ If no FCW were 
issued and the vehicle's CIB system did not offer any braking, release 
of the SV accelerator pedal would not be required prior to impact with 
the POV (i.e., the GVT). Comments were requested on whether this 
proposed approach was reasonable to assess FCW operation.
---------------------------------------------------------------------------

    \163\ The Agency proposed these test procedural changes for its 
PAEB tests as well.
---------------------------------------------------------------------------

    NHTSA asserted that it was appropriate to assess the presence of an 
FCW within CIB (and PAEB) tests because the operation of FCW and AEB/
PAEB systems are complementary and fundamentally intertwined in the 
test scenarios currently assessed by NCAP. Therefore, it seemed 
appropriate to the Agency to begin to assess FCW timing relative to the 
intended onset of CIB activation instead of relative to an ``absolute 
TTC,'' as in NCAP's current FCW tests, since the former would be at the 
discretion of the vehicle manufacturer, which would have explicit 
knowledge of how the operation of their vehicles' CIB systems affect 
the FCW TTC. The Agency proposed to integrate FCW performance 
assessments into its CIB tests rather than DBS tests because, as 
mentioned previously, the Agency had considered removing DBS testing 
from NCAP entirely, and alternatively, weighed performing DBS testing 
at only a limited number of higher speeds. As such, evaluating FCW 
functionality during DBS testing did not seem like a viable option at 
the time.
Alternative 1--Conduct Multiple Separate FCW Assessments
    As an alternative to integrating FCW and CIB tests, NHTSA also 
mentioned that it could maintain the FCW test scenarios currently 
included in its FCW test procedure if commenters suggested the current 
testing approach was more appropriate than its consolidation proposal. 
If the Agency maintained separate FCW and CIB assessments, it proposed 
to align the corresponding maximum SV test speeds, POV speeds, headway, 
POV deceleration magnitude, etc., as applicable, for the FCW tests with 
the included CIB tests (which will be discussed later). More 
specifically, it proposed to adopt the following for NCAP's FCW 
assessments:
     LVS--SV speed of 80 kph (49.7 mph); POV is stationary.
     LVD--SV and POV speed of 50 kph (31.1 mph) or up to 80 kph 
(49.7 mph), depending on the final test speed adopted for the CIB LVD 
scenario; a 12 m (39.4 ft.) SV-to-POV headway; and a POV deceleration 
magnitude of 0.5g.
     LVM--SV speed of 80 kph (49.7 mph); POV speed of 20 kph 
(12.4 mph).
    If the Agency continued to conduct separate FCW assessments that 
aligned procedurally with those required for CIB, NHTSA also reasoned 
it would be necessary to revise the prescribed TTCs currently used to 
assess FCW performance to reflect the revised test scenario and speed 
combinations.\164\ As such, NHTSA sought comment on what TTC would be 
appropriate for each test scenario.
---------------------------------------------------------------------------

    \164\ To pass a test trial, the vehicle must issue the FCW on or 
prior to the prescribed time-to-collision (TTC) specified for each 
of the three FCW test scenarios.
---------------------------------------------------------------------------

    The Agency also proposed a revised assessment approach for FCW (in 
lieu of requiring a pass rate of at least five out of seven runs for 
each FCW test scenario, as is done currently) if FCW assessments were 
not integrated into those for CIB. The Agency proposed to conduct one 
test trial per test speed for each FCW test scenario and to increase 
test speeds in 10 kph (6.2 mph) increments from the minimum test speed 
to the maximum test speed. In the event of a test failure for instances 
where the SV has a relative velocity at impact that is equal to or less 
than 50 percent of the initial SV speed, NHTSA proposed that up to four 
repeat trials would be performed.
Alternative 2--Perform One Indicant FCW Assessment
    Given that most FCW systems are currently able to pass all relevant 
NCAP test scenarios, the Agency also suggested that as an alternative 
to retaining three separate FCW test scenarios (to be conducted per the 
test conditions prescribed for the related CIB tests), it may be 
feasible for NCAP to perform one FCW test (to be conducted per the test 
conditions prescribed for the comparable CIB test) that could serve as 
an indicant of FCW system performance. NHTSA reasoned that taking this 
approach for FCW testing would also reduce test burden, similar to its 
proposal to integrate FCW and CIB testing. For this alternative 
proposal, the Agency sought comment on which one of the proposed CIB 
test scenarios would be most appropriate to adopt for an FCW test to 
assess the performance of FCW systems.
Assessment Method, Number of Trials, and Pass Rate (for Separate FCW 
Assessments)
    NHTSA also requested comment on whether an alternative assessment 
method would be appropriate if the decision was made to retain one or 
more FCW scenarios that would be performed at only a single test speed, 
such as for the LVS and LVM test conditions. In such instances, the 
Agency sought comment on whether it should require one trial per test 
condition (i.e., align with the assessment method proposed for the AEB 
test conditions) or conduct multiple trials instead, similar to the 
approach currently prescribed in NCAP's FCW and AEB tests. If 
commenters preferred that the Agency adopt multiple trials in such 
instances, NHTSA asked how many trials would be appropriate, and what 
would be an acceptable pass rate.
    The changes NHTSA proposed for its FCW test procedure as well as 
possible alternatives are shown in Table 16.

                                         Table 16--FCW Test Scenarios and Conditions--Proposals and Alternatives
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                                  SV Speed (kph  POV Speed (kph  POV Headway (m
                                                         Test scenario               (mph))          (mph))          (ft.))       POV  deceleration (g)
--------------------------------------------------------------------------------------------------------------------------------------------------------
Proposal.....................................               Evaluate FCW during all CIB testing (release throttle within 500 ms after FCW).
Alternative 1................................  LVS.............................       80 (49.7)               0             n/a                      n/a
                                               LVM.............................       80 (49.7)       20 (12.4)             n/a                      n/a
                                               LVD *...........................       80 (49.7)       80 (49.7)       12 (39.4)                      0.5
Alternative 2................................                                 Evaluate FCW in one CIB test condition only.
--------------------------------------------------------------------------------------------------------------------------------------------------------
* For LVD, NHTSA proposed adoption of the highest CIB SV/POV speed for the FCW assessment.


[[Page 95965]]

Summary of Comments
Integrating FCW Assessments Into CIB Testing
    The majority of commenters (BMW, MEMA, DENSO, GM, HATCI, Intel, 
Auto Innovators, Rivian, and TRC) supported the consolidation of FCW 
and CIB tests into a single evaluation. Rivian expressed that combining 
FCW and CIB is appropriate because FCW and AEB rely on the same inputs, 
and FCW is designed to work in a sequential manner with AEB. The 
automaker also mentioned that consolidation of FCW and AEB testing 
would reduce overall test burden, an assertion also expressed by Auto 
Innovators, GM, and TRC. Additionally, TRC mentioned that combining 
assessments for FCW and CIB functionality seemed logical since the 
timing of FCWs is already collected during the Agency's CIB tests. 
IDIADA also articulated this assertion.
    DENSO also noted that it was appropriate to integrate FCW and CIB 
testing since voluntary agreements have helped to standardize CIB. The 
company asserted that this was even more fitting if the Agency was 
considering higher-speed CIB assessments, since Euro NCAP's AEB Car-to-
Car test protocol stipulates assessment of FCW functionality within the 
CIB assessments at even higher speeds than those utilized to evaluate 
CIB functionality. NTSB supported harmonizing NHTSA's FCW test protocol 
with those used by other NCAPs, and consolidating FCW and AEB testing, 
but expressed concern that the proposed maximum SV test speed of 80 kph 
(49.7 mph) is inadequate, as it is only slightly higher than the SV 
speed currently specified in NCAP's FCW test procedure (72.4 kph (45 
mph)).
    Bosch also supported harmonization with Euro NCAP, suggesting that 
NHTSA combine assessments for FCW, CIB, and DBS, as they maintained it 
would be difficult to define acceptable TTCs for FCW alone. Thus, 
instead of specifying prescribed TTCs for FCW, Bosch favored 
stipulating when FCWs should be issued prior to AEB braking. Like 
Bosch, BMW and Auto Innovators stated consolidation of FCW, CIB, and 
DBS testing was appropriate, since all three systems are designed to 
work together to achieve the same goal of rear-end crash avoidance or 
crash mitigation through speed reduction.\165\ The commenters 
recommended that the Agency combine FCW, CIB, and DBS assessments into 
one test series consisting of multiple test scenarios since this would 
better assess the safety rendered by the systems collectively and align 
with other NCAPs globally. They also noted that FCW system requirements 
were determined at a time when FCW and AEB functionalities were not 
necessarily integrated with one another, as they often are currently. 
GM also supported consolidating FCW and CIB/DBS testing like that 
employed in test protocols used in other global NCAPs. The automaker 
expressed that FCW should be assessed as part of the overall system 
performance since AEB systems are now widely available in current 
vehicles and provide additional safety benefits compared to FCWs 
alone.\166\
---------------------------------------------------------------------------

    \165\ Also see Auto Innovators Appendix 1.
    \166\ See GM Attached A and Table 1.
---------------------------------------------------------------------------

    Both GM and Auto Innovators mentioned two potential ways the Agency 
could integrate FCW performance assessments into AEB tests, with both 
affording an overall assessment of system performance. The commenters 
stated the Agency could trigger activation of the brake robot during 
DBS testing based on the timing of the FCW, as is done by Euro NCAP. 
Alternatively, they stated NHTSA could directly assess FCW timing 
during CIB tests if the Agency's FCW and CIB protocols included the 
same test conditions, as is the case currently for the LVM 45_20 
condition. The commenters expressed that appropriate FCW TTCs for the 
other CIB scenarios/conditions could be similarly calculated using the 
same approach NHTSA used to establish criteria for the LVM 45_20 
condition. Although the respondents suggested the latter option may 
provide a simpler test method, they preferred that the Agency adopt the 
methodology employed by Euro NCAP, stating that this method would also 
provide the best indication of appropriate timing for brake pedal 
application. The commenters favored combining FCW and CIB assessments 
over NCAP's current evaluation method, which stipulates separate 
assessments for each technology. This is because the commenters 
supported evaluations for the same test scenarios but over a varying 
range of speeds. If the Agency ultimately chose not to combine FCW and 
AEB assessments, Auto Innovators suggested that it should continue to 
conduct all three of the current FCW test scenarios.
    Advocates stated they supported consolidating FCW and CIB testing 
if NHTSA provided data and analysis to support such a decision, and if 
the Agency was able to ensure the adopted test procedure could 
adequately assess the functionality for each system independently.
    A few commenters, including Honda, Toyota, FCA, and CAS, did not 
support consolidating FCW and CIB testing. Honda stated that it was 
more appropriate to instead consolidate FCW and DBS tests, since the 
two technologies are designed to work in tandem to mitigate or avoid a 
rear-end collision (i.e., the driver is aware of the impending 
collision and responds to the FCW by braking), and CIB is designed to 
operate alone (i.e., the driver is not aware of the impending threat 
and therefore does not apply the vehicle's brakes in response to an 
FCW, and as such, is also unlikely to have released the accelerator 
pedal). FCA and Toyota also supported consolidating FCW and DBS testing 
for similar reasons. FCA stated that CIB can be executed differently 
when the attentiveness of the driver is present, and that automatic 
braking from CIB is more effective at low speeds than manual braking 
resulting from the combination of FCW and DBS, such that FCW would not 
necessarily be issued in such situations. Toyota also supported 
combined FCW and DBS testing because such an approach would be like 
that used by Euro NCAP. Furthermore, in the case of combined FCW and 
CIB testing, the automaker relayed that simply releasing the 
accelerator pedal after FCW activation would not discern the actual 
effectiveness of the FCW system to alert the driver to brake, since 
there would be no large deceleration observed by the time the pedal was 
released. Instead, Toyota asserted that such an approach only serves to 
demonstrate CIB performance regardless of FCW activation.
    CAS asserted that it would only be appropriate to consolidate FCW 
and CIB testing if FCW is a part of the underlying CIB system (such 
that it utilizes identical physical components (e.g., sensors and 
brakes)), if it is provided every time CIB is activated (i.e., uses the 
same logic and parameters for system execution), and if capabilities 
for both systems can be ``separately appreciated and evaluated'' by 
users.
Alternative 1--Conduct Multiple Separate FCW Assessments
    Honda favored combining FCW and DBS tests but stated if the Agency 
chose to keep FCW tests separate, it did not support any adjustment to 
the current FCW tests, unless other commenters suggested differently. 
Intel proposed to consolidate FCW and CIB testing but asserted TTCs 
should be revised and ``carefully selected'' to limit nuisance 
activations if the Agency chooses to continue to conduct separate FCW 
assessments. Intel stated this was

[[Page 95966]]

particularly important for low SV speeds where a high TTC may be 
particularly annoying since a late reaction from the driver could still 
be reasonable and practicable.
    Like Honda and Intel, Bosch also did not support separate FCW 
assessments. As mentioned earlier, the company stated it would be 
challenging to define appropriate TTCs and other performance criteria 
for FCW only, and specifically requested that the current TTC for the 
LVD scenario (i.e., 2.4 seconds) be revised because they considered it 
too difficult for current technology.
    Other commenters expressed that test criteria would have to change 
if the Agency opted to continue with separate FCW assessments. Auto 
Innovators, which supported the conduct of all three of the current FCW 
test scenarios if FCW assessments were not consolidated with those for 
AEB, mentioned that the SV headway should be increased if the current 
FCW tests were to be conducted at higher speeds. FCA opined that NHTSA 
should adjust the TTC criteria if it chooses to amend the test speed 
for the SV, but the automaker did not suggest appropriate TTC values. 
Likewise, Advocates generally mentioned that the Agency would have to 
specify TTCs, test speed, headway, etc. and present the data to support 
its selections to ensure FCW systems continue to elicit the intended 
driver response.
Alternative 2--Perform One Indicant FCW Assessment
    If the Agency were to retain separate FCW assessments, FCA and CAS 
supported retaining all three current FCW test scenarios. CAS added 
that NHTSA should not reduce the number of test scenarios unless it 
could prove that doing so would not negatively affect safety. Advocates 
agreed that any reduction to the number of required tests should be 
supported by data. Furthermore, the group cautioned the Agency not to 
``seek convenience or expediency over the promotion of safety.'' 
Instead, Advocates commented that NHTSA should test the range of 
conditions necessary to ensure FCW systems address the safety need and 
offer robust performance during real-world driving. They recommended 
the Agency establish minimum test criteria to ensure a baseline level 
of safety and use supplemental test criteria (e.g., assessments at 
higher or lower speeds, shorter headways, etc.) to assign additional 
credit to higher-performing systems.
    GM and Auto Innovators favored consolidating FCW, CIB, and DBS 
testing, as is done by other consumer programs, to permit assessment of 
FCW and AEB systems simultaneously and thus minimize test burden. 
However, if the Agency opted to assess FCW separately, the commenters 
favored retaining all three test scenarios (i.e., LVD, LVM, and LVS), 
as FCA and CAS proposed, to ensure (1) consistency with other NCAPs and 
that (2) FCW performance continues to align with the rear-end crash 
problem in the real world.
    Similar to GM and Auto Innovators, Honda supported consolidation of 
FCW and DBS tests. However, the manufacturer also acknowledged not all 
DBS systems may perform well at certain higher test speeds, such as 80 
kph (49.7 mph). Therefore, the manufacturer commented it may be 
necessary to perform one FCW test scenario independently at the maximum 
SV speed to appropriately evaluate FCW performance.
    Intel suggested the Agency should choose either the LVS or LVM test 
scenarios if NHTSA decides to require one test for FCW assessment. The 
company envisioned that procedural changes proposed for the CIB LVD 
test may be especially challenging for FCW systems as the prescribed 
headway (12 m (39.4 ft.)) and POV deceleration (0.5g) will shorten the 
TTC substantially compared to that afforded currently in the FCW LVD 
test (i.e., 30 m (98.4 ft.) and 0.3 g POV deceleration). BMW also 
stated that the proposed LVS test scenario was the most appropriate 
scenario to select to evaluate FCW systems.
Assessment Method, Number of Trials, and Pass Rate (for Separate FCW 
Assessments)
    Auto Innovators and FCA recommended that NHTSA should continue to 
conduct seven trials per scenario and maintain the pass rate of five 
out of seven trials if the Agency retains separate FCW tests. Intel 
also supported retaining multiple trials, stating that conducting three 
trials and adopting a pass rate of two out of three would limit test 
burden while still ensuring robust assessments. For the assessment 
method in general, the company proposed an approach that aligned with 
their comments to PAEB and AEB.
    Stating that FCW is not as important as AEB, IDIADA expressed that 
the Agency should award fewer points for FCW if separate assessments 
will be conducted for this technology.
Accelerator Release Timing (Applicable for FCW Integration)
    With respect to the Agency's proposal for release of the 
accelerator pedal if it was to integrate FCW and AEB tests, FCA stated 
a release time of 500 ms after the issuance of the FCW was appropriate. 
IDIADA also mentioned that a 500 ms pedal release time could be 
acceptable, as FCWs would ``ideally'' be issued 1.2 seconds prior to 
braking. However, Toyota did not agree with releasing the accelerator 
pedal 500 ms after issuance of the FCW if FCW and CIB testing was 
combined since, as mentioned previously, the commenter noted this 
approach would not assess the actual effectiveness of FCW, but rather, 
would just show the effectiveness of CIB.
    Intel suggested an alternative approach to validate FCW 
functionality. The company suggested NHTSA pursue a similar approach to 
that used by the General Safety Regulation (GSR), whereby the Agency 
would require an FCW be issued 0.8 seconds prior to the start of 
autonomous braking (as measured by the deceleration reaching a certain 
level).
    Auto Innovators suggested that NHTSA study drivers' reaction times 
to determine whether releasing the accelerator pedal 500 ms after an 
FCW is issued is appropriate. The organization also opined that 
specifying 0.5g as the threshold indicative of CIB braking in instances 
where no FCW is issued may be too high, such that the release of the 
accelerator pedal should potentially occur at a lower deceleration 
level.
Response to Comments and Agency Decisions
    Based on the comments received, NHTSA has decided to consolidate 
FCW and AEB testing such that an assessment of FCW functionality will 
be assessed during NCAP's CIB and DBS evaluations using LVD, LVS, and 
LVM test scenarios. During these evaluations, the SV must issue an FCW 
prior to the onset of automatic braking (as defined by the instant SV 
deceleration reaches at least 0.15g) for each trial run performed. If 
an FCW is issued, the SV's accelerator pedal will be fully released (at 
any rate) within 500 ms. For DBS testing, manual (i.e., robotic) 
braking will then be imparted 1.0  0.1 seconds after 
issuance of the FCW. If no FCW is issued during a test trial, release 
of the SV accelerator pedal would not be required prior to impact with 
the POV (regardless of whether the vehicle's AEB system offers 
automatic braking), and the SV will fail the trial run. See Figure

[[Page 95967]]

5 for sequence of FCW, throttle release, and brake application in the 
CIB and DBS evaluation tests.
[GRAPHIC] [TIFF OMITTED] TN03DE24.004

    NHTSA notes that the requirement that an FCW be issued prior to the 
onset of automatic braking (as defined by the instant SV deceleration 
reaches at least 0.15g) will not apply to the AEB false positive tests 
since issuance of an FCW and activation of automatic braking is not 
expected in these tests. If an FCW is issued in the CIB false positive 
test, the SV throttle will also be released within 500 ms, as this is 
an existing requirement for this test scenario. Likewise, per the 
existing CIB test procedure, if no FCW is issued during the CIB false 
positive test, the throttle will not be released until the test's 
validity period (the time when all test specifications and tolerances 
must be satisfied) has passed. The Agency is also making no changes to 
throttle release timing or brake application for the DBS false positive 
test. As currently specified for this test, the SV throttle will be 
released within 500 ms of the currently prescribed TTC (2.1 seconds) if 
no FCW is issued by the specified time. If an FCW is issued, the SV 
throttle will be released within 500 ms of the alert. For both 
situations in the DBS test, the SV brakes will then be applied at a TTC 
of 1.1 s, which corresponds to a nominal distance of 24.4 m (80.2 ft.).
Integrating FCW Assessments Into AEB Testing
    The decision to evaluate FCW functionality during CIB and DBS 
evaluations using NCAP's LVD, LVS, and LVM test scenarios differs 
slightly from the Agency's March 2022 proposal. As mentioned earlier, 
NHTSA had proposed to integrate FCW into CIB testing in NCAP. At the 
time, the proposed combination of tests appeared to be the only viable 
option, (if the Agency was to consolidate FCW and AEB testing), since 
NHTSA had considered removing DBS testing from NCAP entirely or 
performing DBS testing at only a limited number of higher speeds. 
However, since the Agency has decided to retain DBS assessments in NCAP 
and will continue to perform DBS tests at multiple speeds, as discussed 
previously, evaluating FCW within DBS testing is also appropriate. 
NHTSA notes that FCA, Honda, and Toyota supported integrating FCW and 
DBS testing, suggesting that such an approach was more appropriate than 
integrating FCW and CIB testing. As Honda stated, FCW and DBS are 
designed to be complementary systems that operate sequentially to 
assist a driver in responding appropriately to prevent a rear-end 
collision. The FCWs the driver to the impending collision, the driver 
responds by braking, and the DBS system offers additional braking in 
instances where the driver's braking alone is insufficient to avoid the 
crash. Therefore, it seems reasonable to evaluate FCW functionality 
(i.e., notification and timing) during NCAP's DBS testing.
    Although CIB systems are designed to operate when the driver is 
unaware or unresponsive to an impending rear-end crash (i.e., the 
driver either does not respond to an FCW by braking or does not have 
time to brake after an FCW is issued), a vehicle should still issue an 
FCW in such situations. First, the vehicle cannot anticipate what 
actions the driver will take. Second, the warning serves to warn the 
driver not only of the crash threat but also of the onset of sudden 
profound braking, which can be alarming in itself. For these reasons 
the Agency has also decided to require the FCW be issued prior to 
automatic braking during NCAP's CIB assessments. While the Agency 
acknowledges Toyota's assertion that integrating FCW and CIB 
assessments ``only serves to demonstrate CIB performance regardless of 
FCW activation,'' the consolidation of FCW and CIB assessments permits 
an overall assessment of FCW functionality in situations where the 
driver may still find an alert to be beneficial.
    The requirement that an FCW be issued prior to the onset of 
automatic braking (as defined by the instant SV deceleration reaches at 
least 0.15g) will apply for all test speed and scenario combinations 
used during the conduct of the NCAP's CIB and DBS evaluations, except 
for the false positive scenarios. By adopting this requirement, it is 
not necessary to calculate appropriate FCW TTCs for all AEB test 
conditions, as Auto Innovators and GM suggested. Rather, the presence 
of FCW will simply be assessed in the context of the AEB system as a 
whole.
    Although FCA expressed that automatic braking from CIB may be more 
effective at low speeds compared to driver braking and subsequent DBS 
intervention, NHTSA does not agree with the manufacturer that an FCW is 
not needed at lower speeds for a particular intervention method (i.e., 
automatic braking from CIB compared to driver braking and subsequent 
DBS engagement). For the reasons mentioned previously, an FCW should 
always be issued prior to automatic braking in the real-world 
situations represented by the Agency's AEB testing. Additionally, well-
designed FCWs can provide significant safety benefits in crash-imminent 
rear-end crash scenarios. NHTSA encourages vehicle manufacturers to 
present them so that the driver may be able to respond with sufficient 
time to avoid a crash (i.e., not to solely rely on CIB activation for 
crash

[[Page 95968]]

avoidance). That being said, the Agency is not prescribing that the FCW 
be issued at a specific time prior to braking in each test, as several 
commenters recommended. NHTSA should afford manufacturers with 
flexibility in this regard so they may design systems that are most 
appropriate for the complexities of various crash situations, some of 
which may provide very little time for a driver to take action to avoid 
a crash. Although the Agency reasons a requirement that an FCW be 
issued prior to automatic braking is appropriate for pre-defined 
scenarios during track testing, it does not want to be overly 
prescriptive such that automatic braking is suppressed in certain 
situations during real-world driving, such as when a lead vehicle cuts 
immediately in front of an AEB-equipped vehicle, where it may not be 
appropriate to delay immediate automatic braking in anticipation of a 
driver warning.
    NHTSA acknowledges BMW's and Auto Innovators' recommendation that 
the Agency combine FCW, CIB, and DBS assessments into one test series 
consisting of multiple test scenarios to assess the total safety 
provided by the systems collectively; however, this is not feasible 
given the Agency's desire to provide assurance of both CIB and DBS 
system functionality. Driver-imparted manual braking may not be 
provided in all real-world situations; thus, it is beneficial to 
evaluate the performance of CIB systems devoid of DBS intervention. 
Further, the Agency agrees with FCA's assertion that manufacturers may 
choose to execute CIB differently when the driver is attentive and 
responsive (i.e., situations represented by DBS testing) compared to 
when they are not (i.e., situations represented by CIB testing). The 
Agency aims to ensure system effectiveness in both situations.
Conducting Separate FCW Assessments
    The Agency has decided not to conduct separate FCW assessments. 
NHTSA's decision to expand upon its proposal to evaluate FCW 
functionality in both CIB and DBS assessments aligns well with 
recommendations made by many commenters, including Auto Innovators, 
Bosch, BMW, and GM. Respondents supported integration of FCW, CIB, and 
DBS testing for various reasons, including harmonization and a 
reduction in test burden. As mentioned by commenters, FCW is designed 
to work in a sequential manner with AEB, and AEB provides additional 
safety benefits compared to FCWs alone. Therefore, NHTSA reasons it is 
no longer necessary to assess FCW independent of AEB. Although Honda 
supported FCW and AEB consolidation, the commenter also asserted it may 
be necessary to perform one separate FCW test to assess system 
functionality at higher speeds (i.e., 80 kph (49.7 mph)) since not all 
DBS systems may perform well when tested. Similarly, NTSB suggested 
that NHTSA pursue FCW assessments at test speeds in excess of 80 kph 
(49.7 mph). Since the Agency will perform LVS and LVM DBS assessments 
for test speeds of 80, 90, and 100 kph (49.7, 55.9, and 62.1 mph), and 
vehicles will be required to issue an FCW prior to automatic braking 
for all AEB test conditions to be evaluated (except for the false 
positive test conditions), it is unnecessary to conduct a separate 
high-speed assessment specifically to evaluate FCW functionality. 
Vehicles unable to meet the Agency's FCW requirement will fail an AEB 
test trial.
Accelerator Release Timing
    The Agency has decided to proceed with adopting its proposal for 
accelerator release timing. The SV's accelerator pedal will be fully 
released at any rate within 500 ms after an FCW is issued during all 
CIB and DBS evaluations using LVD, LVS, and LVM test scenarios. This 
timing is consistent with that specified in NCAP's current CIB and DBS 
test procedures, and the approach (i.e., releasing the throttle after 
the FCW is issued) matches that prescribed in Euro NCAP's AEB Car-to-
Car systems test protocol. The Agency notes Euro NCAP specifies the 
pedal be released 1.0 second after issuance of the FCW during manual 
braking tests. Since NHTSA's test laboratories have not experienced 
difficulties with releasing the accelerator pedal within 500 ms, as 
currently specified in the current test procedure, the Agency sees no 
reason to adopt Euro NCAP's requirement instead. Loosening the 
requirement would only serve to increase the likelihood that an 
accelerator pedal application may interfere with AEB engagement.
    Although NHTSA had also proposed that the SV accelerator pedal 
would be fully released within 500 ms after the onset of automatic 
braking (as defined in the Agency's proposal as the instant SV 
deceleration reaches at least 0.5g) \167\ for CIB and DBS tests if no 
FCW is issued, this additional requirement is seemingly unnecessary 
since the Agency has decided that a vehicle would fail a trial in such 
instances. As such, if no FCW is issued during a CIB or DBS evaluations 
using LVD, LVS, or LVM test scenarios, release of the SV accelerator 
pedal would not be required prior to impact with the POV.
---------------------------------------------------------------------------

    \167\ NHTSA notes that, pursuant to other changes made in this 
notice, the onset of automatic braking will be defined as 0.15g 
instead of 0.5g for NCAP's future AEB tests.
---------------------------------------------------------------------------

    For false positive testing, as stated earlier, the SV accelerator 
pedal will be released within 500 ms of an FCW if one is issued in the 
CIB false positive test; however, if no FCW is issued, the accelerator 
pedal will not be released until the test's validity period has passed. 
For the DBS false positive test, the SV accelerator pedal will be 
released within 500 ms of the currently prescribed TTC (2.1 seconds) if 
no FCW is issued by the specified time; if an FCW is issued, the SV 
throttle will be released within 500 ms of the alert.
Defining the Onset of Automatic Braking
    While there is no need to define the term ``onset of automatic 
braking'' for the purpose of releasing the accelerator pedal (given the 
decisions made herein), a definition of the term is needed to determine 
whether a vehicle's FCW timing meets the adopted requirements for 
passing performance. Instead of defining the onset of automatic braking 
as 0.5g, as proposed, the Agency has decided to define the onset of 
automatic braking as a deceleration of 0.15g. NHTSA agrees with Auto 
Innovators that a 0.5g threshold may be too high. The Agency now 
reasons a 0.15g threshold is appropriate based on its experience 
conducting AEB testing for NCAP. This value has proven to be a reliable 
marker for AEB onset during the program's track testing.\168\ As will 
be discussed, a vehicle cannot pass an NCAP AEB LVS, LVM, or LVD test 
trial unless the required FCW is presented prior to the onset of 
automatic braking (i.e., CIB), as defined by the instant SV 
deceleration reaches at least 0.15g.
---------------------------------------------------------------------------

    \168\ https://www.regulations.gov/document/NHTSA-2021-0002-0002.
---------------------------------------------------------------------------

    Since NHTSA has decided to integrate FCW and AEB testing rather 
than conduct separate FCW assessments, the Agency does not see the need 
to address comments received in this regard that are specific to an 
appropriate assessment method, number of trials, and pass rate solely 
for FCW.
b. FCW Signal Modalities
    Currently, NHTSA gives credit to vehicles having FCW systems that 
send visual, auditory and/or haptic warning signals that meet the TTC 
requirements outlined in NCAP's FCW test procedure. The Agency's 
research has provided mixed results surrounding warning signal 
effectiveness. In one study, the Agency found that presenting drivers 
with an auditory warning in medium or

[[Page 95969]]

high urgency situations significantly reduced crash severity relative 
to visual and tactile (or haptic) warnings.\169\ However, in other 
research studying the response of distracted human subjects to FCWs in 
forward collision crash scenarios on a test track, NHTSA found that 15 
of the 17 total crashes that were successfully avoided (88 percent) 
occurred during trials performed with a seat belt pretensioner-based 
haptic alert. Only one crash was avoided during a trial performed with 
a beep-based auditory-only alert.\170\ Research conducted by other 
entities has also suggested that haptic warning signals may increase 
consumer acceptance of FCW technologies compared to auditory 
alerts.\171\
---------------------------------------------------------------------------

    \169\ Lerner, N., Robinson, E., Singer, J., Jenness, J., Huey, 
R., Baldwin, C., & Fitch, G. (2014, September), Human factors for 
connected vehicles: Effective warning interface research findings 
(Report No. DOT HS 812 068), Washington, DC: National Highway 
Traffic Safety Administration.
    \170\ Forkenbrock, G., Snyder, A., Heitz, M., Hoover, R. L., 
O'Harra, B., Vasko, S., and Smith, L. (2011, July), A Test Track 
Protocol for Assessing Forward Collision Warning Driver-Vehicle 
Interface Effectiveness (Report No. DOT HS 811 501), Washington, DC: 
National Highway Traffic Safety Administration.
    \171\ Flannagan, C., LeBlanc, D., Bogard, S., Nobukawa, K., 
Narayanaswamy, P., Leslie, A., Kiefer, R., Marchione, M., Beck, C., 
and Lobes, K. (2016, February), Large-scale field test of forward 
collision alert and lane departure warning systems (Report No. DOT 
HS 812 247), Washington, DC: National Highway Traffic Safety 
Administration.
---------------------------------------------------------------------------

    Based on these findings, the Agency sought comment on whether it 
should give credit to vehicles equipped with FCW systems that only 
provide a passing auditory warning or whether it should also give 
credit to those FCW systems that only provide passing haptic signals 
(if it chose to retain one or more separate FCW tests).\172\ NHTSA 
questioned whether haptic warning signals can be accurately and 
objectively assessed, and if so, whether certain haptic signal types 
should be excluded from consideration (if the Agency was to award 
credit to vehicles with haptic warnings that pass NCAP tests) because 
they may be a nuisance to drivers such that they would be more likely 
to disable them. NHTSA further questioned whether, for separate FCW 
evaluations, it should no longer give credit to FCW-equipped vehicles 
that offer only visual FCW signals. Finally, the Agency sought comment 
on what type(s) of FCW signal(s) would be acceptable for use in 
defining the timing of the release of the SV accelerator pedal if the 
Agency decided to assess the sufficiency of an FCW in the context of 
CIB (and PAEB) tests in lieu of separate FCW assessments.
---------------------------------------------------------------------------

    \172\ NHTSA proposed that it would give credit to FCW systems 
that have both passing auditory and haptic alerts if both alert 
types were available. However, if a vehicle with such a system 
provided only a passing haptic alert and the Agency decided only to 
give credit to systems that provided passing auditory alerts, then 
the vehicle would not receive credit as having met the Agency's FCW 
test requirements.
---------------------------------------------------------------------------

Summary of Comments
Allow All Warning Signal Modalities
    Those in favor of not restricting the type of FCW signal modality 
permitted during Agency testing included CAS, HATCI, and Intel. HATCI 
stressed the importance that NHTSA be flexible with respect to warning 
signal type(s), contending that ``[current] flexibilities allow 
industry to optimize and adjust the alerts based on the multitude of 
ADAS technology installed, the interaction between the technologies, 
and research and development findings.'' The manufacturer warned that 
restricting system warning signals to specific modalities may limit 
future alert strategies (e.g., combinations, locations) and have 
unintended consequences (e.g., reduced alert effectiveness) as ADAS 
technology evolves and other systems are introduced. Instead of 
prescribing alert types, HATCI suggested that NHTSA work with industry 
and/or established standards bodies (e.g., Society of Automotive 
Engineers, or SAE) to define process-based and/or performance-based 
methods to assess alert effectiveness.
    Intel mentioned that modality should not be restricted since credit 
should be based on warning effectiveness (i.e., a warning resulting in 
passing performance is effective, regardless of the signal modality). 
CAS agreed that any effective implementation of warning signal type(s) 
should be considered acceptable since FCW activation during real-world 
driving should rarely occur.
Restrict Warning Signal Modalities
    A few commenters recommended the Agency award credit only to 
certain FCW signal modalities. MEMA, FCA, Bosch, and Subaru stated that 
credit should be awarded for only auditory or haptic warnings. Although 
Bosch supported awarding credit for both auditory and haptic warnings 
and considered itself to be ``technology agnostic'' in general, the 
company also reasoned that haptic warnings are more likely to seize the 
attention of the driver. If a specific haptic warning (e.g., steering 
wheel vibration) is implemented for a specific technology (e.g., FCW), 
Bosch asserted strongly that the same haptic warning (e.g., steering 
wheel vibration) should not also be paired to a different technology 
(e.g., BSW) to avoid confusing the driver.
    Subaru stated that credit should be awarded to auditory and haptic 
FCW signals since they are the most effective. The company cited the 
Agency's research findings pertaining to the effectiveness of auditory 
warnings versus visual and haptic warnings referenced in its March 9, 
2022, RFC Notice \173\ (and above) as justification to award credit to 
auditory warnings.
---------------------------------------------------------------------------

    \173\ 87 FR 13477.
---------------------------------------------------------------------------

    NTSB supported awarding credit to vehicles offering auditory 
unimodal FCW or bimodal FCWs that include an auditory component. In 
general, the commenter did not support awarding credit to vehicles 
offering haptic FCW signals as the group noted that there is large 
variation in the implementation of haptic warnings (e.g., seat, 
steering wheel, seat belt); therefore, it would not be prudent to 
assume equivalent effectiveness without supporting research. Finally, 
ZF Group suggested the Agency should award credit to haptic seatbelt 
warnings when considering approved warning signal modalities, as their 
research has shown them to be highly effective.
Add Requirements to Visual Warning Signals or Require Multiple 
Modalities
    Several commenters, including NTSB and DRI, remarked that visual-
only warnings should not be considered acceptable to earn FCW credit. 
NTSB cited the low effectiveness of visual-only warnings as the reason 
not to award credit to visual FCWs.\174\ The group also referenced 
several crash investigations where visual warnings failed to capture 
drivers' attention when the vehicle was operating in partial automation 
mode at the time of the crash.\175\
---------------------------------------------------------------------------

    \174\ https://www.regulations.gov/comment/NHTSA-2021-0002-1530. 
See footnote 15.
    \175\ https://www.regulations.gov/comment/NHTSA-2021-0002-1530. 
See footnote 16.
---------------------------------------------------------------------------

    DRI also suggested the Agency discontinue the acceptance of visual 
warnings or ``alternatively prescribe minimum characteristics of the 
alerts (size, color, brightness, location)'' to gain the driver's 
attention. The test laboratory stated that in many FCW systems, the 
visual warning signal, which is typically a telltale in the instrument 
panel that changes color, is ``too small,'' appears in ``non-attention-
capturing colors (e.g., white),'' or is otherwise inconspicuous. The 
company also reasoned that a distracted driver's gaze would likely not 
be forward-looking, such that a visual warning located in the 
instrument panel would

[[Page 95970]]

not capture the driver's attention as well as an auditory or haptic 
warning. However, DRI suggested that a large, bright visual warning in 
an attention-capturing color, such as red, may suffice. DRI further 
surmised that a visual FCW is often intended to be an indicator to a 
driver regarding the ``real'' alert, which may be auditory or haptic, 
such that it serves to ``communicate visually to the driver why they 
are hearing a warning beeping, rather than [the visual alert] being a 
warning in and of itself.'' As such, the laboratory, along with an 
anonymous commenter, opined that visual FCWs are not effective at 
warning the driver unless they are combined with an auditory or haptic 
warning signal. IDIADA agreed that visual warnings alone are 
insufficient to capture the driver's attention since they may not be 
looking at the instrument panel, and as such, recommended the Agency 
award credit to vehicles offering a combination of visual and auditory 
warnings.
    GM stated that multimodal (e.g., visual plus directional auditory 
or directional haptic) warnings are necessary for ``imminent'' crash 
warnings, but visual-only signals are acceptable for ``cautionary'' 
crash alerts. The manufacturer suggested that multimodal warnings may 
increase consumer acceptance and limit instances of drivers turning off 
FCW systems due to annoyance. However, GM opined that NHTSA should only 
provide credit to vehicles in NCAP testing offering multimodal FCWs 
that include both a visual and haptic or auditory signals. Like DRI, GM 
also suggested the Agency impose additional requirements for visual 
warning signals, recommending that visual alerts should explain the 
nature of the warning and should be located such that they ``draw the 
driver's attention to the general direction of the crash threat.'' This 
directional requirement, referenced previously, was also suggested for 
haptic and auditory components of multimodal warnings. The manufacturer 
suggested that acceptable visual FCWs should include a ``red flashing 
imminent alert and be placed in the lower, center portion of the 
driver's forward field-of-view,'' like a translucent red flashing alert 
reflected on the lower part of the vehicle's windshield, to draw the 
driver's attention forward, in the direction of the crash threat, 
stating this may facilitate a rapid, appropriate response by the 
driver.
    With respect to haptic warnings, GM suggested the Agency should 
award additional credit to their Safety Alert Seat (SAS) vibration 
alerts, and to other haptic alerts shown to support equivalent 
rationale.\176\ According to GM, SAS vibration alerts are triggered 
simultaneously with an auditory alert by the same ADAS signal and can 
be detected by various means during testing (e.g., voltage readings, 
vibration sensors, auditory microphone, etc.). GM explained they allow 
non-visual crash alerts to be detected by hearing-impaired drivers, 
thus improving accessibility. GM further stated a large-scale 
telematics-based study funded by NHTSA found that, compared to auditory 
warnings, SAS warnings produced braking at the same time after issuance 
of an FCW, were preferred by drivers, and increased usage of not just 
the FCW system overall, but also the most conservative alert timing 
setting (i.e., ``Far'').\177\
---------------------------------------------------------------------------

    \176\ https://www.regulations.gov/comment/NHTSA-2021-0002-3856. 
See Appendix 2 for rationale and supporting data.
    \177\ DOT HS 812 247.
---------------------------------------------------------------------------

    Several other commenters (BMW, Subaru, Rivian, and Auto Innovators) 
also favored systems offering multimodal warning strategies, 
specifically auditory or haptic warning signals in combination with 
visual signals. Auto Innovators suggested that vehicles having haptic 
or auditory warnings could receive a greater number of points than 
those offering only visual warnings if the Agency was to implement a 
rating system for FCWs. Similarly, Subaru supported awarding more 
points to FCW systems that provide a combination of warning signal 
modalities. Rivian suggested that drivers could be given the option to 
turn off either the auditory or haptic warning to suit their 
preference. To limit driver nuisance, the commenter stated NHTSA should 
provide a recommended decibel level for auditory warnings and a 
recommended type and location for haptic warning signal presentation, 
but not restrict system designs. As stated previously, NTSB also 
implied that bimodal auditory warnings (i.e., auditory plus visual) 
would be preferred.
Other Related Comments
    Auto Innovators requested that the Agency clarify what constitutes 
an alert. Specifically, the group asked whether alerts at the steering 
wheel, driver's seat, and pedal qualify as haptic alerts, in addition 
to system-induced vehicle braking at low deceleration levels (i.e., 
partial braking). The commenter mentioned that, per Euro NCAP's 2023 
update, the organization now considers partial braking to be an 
approved haptic warning. DRI posed a similar question. The commenter 
cited section 11.5.2.4 of the Agency's FCW test procedure, which 
states, ``The FCW system shall provide a warning to the driver by 
presenting an auditory alert, visual alert, haptic vibration, haptic 
vehicle cue (e.g., braking vibration, steering vibration, or seat 
vibration),'' and asked whether the Agency intended to include ``a 
brake tug,'' defined as a short (0.3 seconds) system-supplied braking 
at a low, 0.2 g deceleration, as a valid warning modality. DRI stated 
it considers ``a brake tug'' to be an effective FCW that should be 
accepted.
    Advocates recommended that the Agency conduct research to identify 
which FCW warning signal modalities will increase use, reduce 
dissatisfaction, and be most effective at reengaging the driver and 
eliciting a safe, timely, and appropriate response. The organization 
also suggested there may be further benefit realized from standardizing 
warnings, especially for drivers that use multiple vehicles.
Response to Comments and Agency Decisions
FCWs Must Include Auditory and Visual Signals
    Based on the comments received and the general support for use of a 
multimodal FCW strategy, the Agency has decided that a vehicle must 
present a forward collision warning consisting of auditory and visual 
warning signals to the vehicle operator to receive credit in each of 
NCAP's LVD, LVM, and LVS AEB tests.
    Use of a multimodal FCW will ensure most drivers will perceive the 
warning as soon as it is presented, allowing the most time for the 
driver to take evasive action to mitigate or, if possible, avoid a 
crash. Further, a multimodal FCW strategy is consistent with the 
recommendations of multiple U.S. and international organizations, 
including Euro NCAP, the ISO, and SAE International. ISO recommends a 
multimodal approach in both ISO 15623, ``Forward vehicle collision 
warning systems--Performance requirements and test procedures,'' and 
ISO 22839, ``Forward vehicle collision mitigation systems--Operation, 
performance, and verification requirements'' (which applies to light 
and heavy vehicles). SAE addresses the topic of a multimodal FCW 
strategy in both information report J2400 2003-08, ``Human Factors in 
Forward Collision Warning Systems: Operating Characteristics and User 
Interface Requirements,'' and J3029, ``Forward Collision Warning and 
Mitigation Vehicle Test Procedure and Minimum

[[Page 95971]]

Performance Requirements--Truck and Bus (2015-10; Work in Progress 
currently).''
    While no one signal combination was preferred by commenters, 
NHTSA's decision to impose a standardized auditory plus visual alert 
strategy for NCAP is appropriate given most of these organizations' 
recommendations specify an FCW consisting of auditory and visual 
signals, though ISO 15623 specifies that an FCW include a visual 
warning as well as an auditory or haptic signal. Euro NCAP also defines 
an FCW as an audio-visual warning.\178\ The Agency's decision to adopt 
a combined auditory/visual bimodal alert aligns well with its ``Human 
factors design guidance for driver-vehicle interfaces'' report,\179\ 
which contains best practice information for implementation of various 
alerts, including those for FCW. Based on cited research, the report 
suggests ``collision avoidance performance for both forward and side 
object collisions may be best when a bimodal auditory/visual warning 
system is used, which extends across driving scenarios, types of 
collisions, and driver populations.'' Requiring a bimodal auditory/
visual alert also seems reasonable considering FCWs comprised of 
auditory and visual signals are prevalent in current U.S. vehicle 
models, thus limiting manufacturer burden.
---------------------------------------------------------------------------

    \178\ TFCW is determined by the auditory portion of 
the warning in Euro NCAP's test procedure.
    \179\ Campbell, J.L., Brown, J.L., Graving, J.S., Richard, C.M., 
Lichty, M.G., Sanquist, T., . . . & Morgan, J.L. (2016, December). 
Human factors design guidance for driver-vehicle interfaces (Report 
No. DOT HS 812 360). Washington, DC: National Highway Traffic Safety 
Administration.
---------------------------------------------------------------------------

    The Agency recognizes that multiple commenters sought flexibility 
for automakers to use an FCW of their own preference in lieu of one 
prescribed by NHTSA to optimize warning strategies for other 
technologies in the future. However, as Advocates suggested, 
standardizing FCW signal modalities may simplify a consumer's 
understanding of these warnings while hastening a driver's recognition, 
and thus, response, to them. As commenters provided no data concerning 
consumers' degree of understanding of the wide variety of FCW 
implementations currently--they simply made generalized statements 
about consumer familiarity--NHTSA does not view these arguments as 
sufficient to overcome the value of standardization as a means of 
ensuring consumer familiarity with FCWs. FCW components that differ by 
manufacturer and across models may cause confusion for drivers, 
especially when driving new, unfamiliar, or rental vehicles. 
Consistency of alerts to the extent possible should improve a driver's 
ability to quickly comprehend the nature of the alert and the reason 
behind any AEB intervention. Although NHTSA acknowledges that studies 
exist which suggest that, depending on design, alternative warning 
types (i.e., visual and haptic, auditory and haptic, or haptic-only) 
can also be effective, without overwhelming data to suggest that one of 
these alert types/combinations is more effective than a combined 
auditory/visual FCW, ensuring standardization of a familiar alert 
option would best serve consumers.
Option To Include Supplementary Haptic Signal
    Although the Agency will require a combined auditory/visual FCW, a 
vehicle may additionally present a haptic signal to warn of an 
impending collision without penalty. As several commenters noted, some 
vehicle manufacturers incorporate a haptic component into their 
products' FCWs. These may include vibrations in the steering wheel, 
driver's seat, and/or pedal, ``tugs'' on the driver's seat belt, or 
system-induced vehicle braking at low deceleration levels (i.e., 
partial braking), including ``brake tugs.'' \180\ There is no current 
evidence to show that haptic FCW signals themselves are detrimental to 
safety. In fact, Euro NCAP awards extra human machine interface (HMI) 
credit to systems offering supplementary haptic alerts that meet 
certain criteria.\181\ Thus, the Agency does not want to discourage 
manufacturers from incorporating haptic alerts as an optional addition 
if they so choose. That said, NHTSA advises vehicle manufacturers to 
carefully implement haptic signals such that they will not be confused 
with those currently used for other crash avoidance technologies, such 
as those related to lane keeping or blind spot detection. The issuance 
of an FCW will not be considered complete during NCAP tests until both 
auditory and visual components are provided.
---------------------------------------------------------------------------

    \180\ These examples of ``haptic vehicle cues'' are currently 
permitted under Section 11.5.2.4 of NCAP's current FCW test 
procedure. See Docket No. NHTSA-2006-26555-0134.
    \181\ Euro NCAP Assessment Protocol--Safety Assist, Collision 
Avoidance, Version 10.4. December 2023.
---------------------------------------------------------------------------

Warning Signal Timing
    During DBS tests performed with LVD, LVM, and LVS scenarios, 
release of the SV's accelerator pedal will not be initiated (and thus, 
the brake will not be applied) until after issuance of the required 
auditory and visual signals. However, a vehicle cannot pass a DBS test 
trial unless the two required FCW signals are presented prior to the 
onset of automatic braking (i.e., CIB), as defined by the instant SV 
deceleration reaches at least 0.15g.\182\ In other words, if automatic 
braking stemming from CIB occurs prior to the issuance of either signal 
(auditory or visual) from the required bimodal FCW, the vehicle will 
fail a test trial even if it does not make contact with the vehicle 
test device. However, if automatic braking from CIB occurs prior to the 
application of manual braking used to assess DBS but after the required 
FCW signals are presented, the vehicle can pass a test trial if it does 
not contact the POV. NHTSA reasons that this procedural requirement not 
only aligns with the intent of DBS tests (i.e., for an inattentive 
driver to respond to the FCW by braking prior to CIB system 
intervention), but it should also make certain that the driver is 
presented with a warning with sufficient time to react to an impending 
rear-end crash even if CIB intervention begins relatively soon after 
the FCW is issued. In addition, it should ensure a vehicle's FCW 
affords real-world effectiveness. If one or more of the required 
components of the bimodal FCW are not issued, release of the SV 
accelerator pedal would not be required prior to impact with the 
vehicle test device (i.e., POV).
---------------------------------------------------------------------------

    \182\ NHTSA clarifies that FCW onset would be determined via 
measurement of the FCW auditory signal sound output within the 
vehicle cabin and the illumination of the FCW visual signal. CAN bus 
information would not be used to assess FCW onset.
---------------------------------------------------------------------------

    NHTSA is requiring that both FCW signals be issued before the 
accelerator pedal is released in DBS tests because, as DRI asserted 
with respect to visual cues, for bimodal alerts, one FCW signal often 
serves as a secondary, confirmatory indication that explains to the 
driver what the primary signal is intended to communicate (i.e., a 
forward crash-imminent situation). Therefore, it seems reasonable to 
require both signals be issued to provide a timely response so the 
driver can recognize the purpose of the FCW, release the accelerator, 
and brake.
    While the Agency's CIB test represents a different real-world 
situation compared to its DBS test, adopting a similar test approach 
for CIB is reasonable. As mentioned, NHTSA's DBS tests represent 
situations where an inattentive driver re-engages in the driving task 
in response to an FCW (or simply in response to noticing a crash-
imminent situation) and applies the brakes to avoid or mitigate a rear-
end

[[Page 95972]]

crash. On the other hand, the Agency's CIB tests are designed to 
represent situations in which the driver does not brake. For instance, 
the driver may respond to the FCW by releasing the throttle but still 
fail to manually apply the brake pedal. Since the vehicle cannot 
anticipate what actions the driver will or will not take in a crash-
imminent situation, the Agency expects that an FCW would/should always 
be issued. In situations where the driver does not respond by braking 
(such as those represented by NHTSA's CIB tests), the alert serves to 
inform the driver that the vehicle is going to intervene. As such, for 
NHTSA's LVD, LVM, and LVS CIB testing, like for its DBS tests, the 
Agency will release the SV's accelerator pedal after the issuance of 
both FCW components (i.e., the visual and auditory signal), and a 
vehicle will fail a CIB test trial (even if it does not contact the 
vehicle test device) if both FCW signals are not issued prior to the 
onset of automatic braking (i.e., CIB), as defined by the instant SV 
deceleration reaches at least 0.15g. Furthermore, if one or more of the 
two required alert signals from the bimodal FCW are not issued, release 
of the SV accelerator pedal would not be required prior to impact with 
the vehicle test device (i.e., POV).
Additional Requirements for Specific Warning Signal Types
    At this time, the Agency is not prescribing additional requirements 
for visual or auditory warning signals (e.g., color, location, decibel 
level, type, etc.) as some commenters suggested, and it is not 
standardizing FCW beyond defining signal types, as requested by 
Advocates. It is outside the scope of NCAP (a consumer information 
program) to be prescriptive in this regard.
c. Adjustable Setting for FCW/AEB
    NCAP's current FCW test procedure states that if an FCW system 
provides a warning timing adjustment setting for the driver, at least 
one timing setting must meet the TTC warning criteria specified in the 
procedure. Therefore, if a vehicle is equipped with a warning timing 
adjustment, only the most conservative (i.e., earliest) warning setting 
is presently tested. However, in its March 2022 RFC notice, the Agency 
acknowledged that while selecting the most conservative setting is 
beneficial for track testing where the driver of the SV must steer and/
or brake to avoid a crash with the POV after the FCW is issued, another 
setting may be more appropriate for NCAP evaluation.
    NHTSA recognized that many consumers may not adjust the warning 
timing setting for FCWs, and those that do may be unlikely to select 
the earliest setting since this setting is most likely to result in 
false positive warnings (i.e., nuisance warnings) during real-world 
operation.\183\ The Agency also expressed that selecting the earliest 
(i.e., most conservative) FCW setting may allow a vehicle to pass 
NCAP's FCW test, whereas later warning settings may not earn NCAP 
credit. Accordingly, NHTSA voiced concern that its FCW test results for 
such vehicles may not accurately represent drivers' real-world 
experiences.
---------------------------------------------------------------------------

    \183\ Nodine, E., Fisher, D., Golembiewski, G., Armstrong, C., 
Lam, A., Jeffers, M.A., Najm, W., Miller, S., Jackson, S., and 
Kehoe, N. (2019, May), Indicators of driver adaptation to forward 
collision warnings: A naturalistic driving evaluation (Report No. 
DOT HS 812 611), Washington, DC: National Highway Traffic Safety 
Administration.
---------------------------------------------------------------------------

    Based on these considerations, the Agency proposed to test the 
middle (or next latest) FCW system setting when performing FCW (and 
AEB/PAEB) NCAP tests on vehicles that offer multiple FCW timing 
adjustment settings. Selection of the middle or next latest warning 
setting for testing would harmonize with Euro NCAP's AEB Car-to-Car 
systems test protocol, thus potentially driving costs down for 
manufacturers and attempting to ensure that consumers in both the U.S. 
and European markets benefit from similar FCW system settings.\184\ The 
Agency noted that the proposed procedural change would uphold the 
mandate in the BIL that NHTSA consider harmonization with third-party 
safety rating programs when practicable. NHTSA requested comments on 
whether testing the middle (or next latest) FCW system setting was 
acceptable or whether another setting would be more appropriate.
---------------------------------------------------------------------------

    \184\ European New Car Assessment Programme (Euro NCAP) 
(December 2023), Test Protocol--AEB Car-to-Car systems, Version 4.3. 
See section 7.4.1.1.
---------------------------------------------------------------------------

Summary of Comments
Middle or Next Latest Timing Setting
    Many commenters (FCA, Honda, Bosch, NTSB, Advocates, and NYC DOT/
NYC DCAS, Vision Zero Task Force) suggested that the middle (or next 
latest) FCW system setting should be utilized for testing. Honda stated 
this setting was ``the best compromise'' to evaluate system 
capabilities. AAA also asserted the middle setting was most appropriate 
because it should be less likely to ``bias system response relative to 
endpoint settings.'' That said, the commenter also opined that if the 
system automatically reverts to a certain setting with each key cycle, 
that setting should be utilized for testing instead. NYC DOT/NYC DCAS, 
Vision Zero Task Force favored the middle (or next latest) FCW setting 
to ``eliminate grade inflation'' and ensure systems perform well under 
conditions consumers would expect them to. Advocates favored the middle 
or next latest setting to harmonize with Euro NCAP test protocols if 
such an approach did not negatively affect FCW safety benefits, such as 
if the vehicle exhibited a significant degradation in performance when 
an alternative alert setting was chosen, particularly if that setting 
was favored by the majority of consumers.
    Some commenters did not favor assessments that utilized the middle 
FCW setting. Intel stated that by choosing the middle setting, TTC 
thresholds may increase, which may be perceived as a nuisance by many 
drivers such that they would turn off the FCW system. The commenter 
suggested that the Agency could utilize the middle setting if it 
reduced the TTC requirements for the FCW tests. GM contended that if 
NHTSA was to select the middle setting for testing, automakers would 
alter FCW system designs accordingly to align current default settings 
to the test settings (i.e., middle) to limit the possibility of 
unexpected performance differences.
    If NHTSA was to choose the middle setting for testing, HATCI asked 
for clarification on what setting would be used if the vehicle has only 
two settings.
Factory Default Timing Setting
    Several commenters stated that the Agency should select the factory 
default setting for testing purposes when driver configuration is 
available. BMW and Rivian mentioned that such system settings are 
rarely changed and therefore the default setting is most likely to be 
the one enabled. BMW commented that vehicle manufacturers should inform 
NHTSA of the default setting, and if such information is not provided, 
the Agency should utilize the middle (or next latest) setting during 
testing. As mentioned previously, Tesla also favored testing with the 
factory default setting (for any configurable FCW or AEB setting), 
contending that the default setting is the most-used setting by 
drivers, ``best represents the vehicle manufacturer's intended system 
performance,'' and would best ensure consistency across vehicle models. 
The automaker mentioned that different settings may result in a 1.0 
second variation (earlier or later compared to other settings) which 
would have varying impacts on performance.
    HATCI also proposed that NHTSA utilize the default system settings 
during testing. HATCI noted their

[[Page 95973]]

research has shown that most Hyundai and Kia customers do not change 
ADAS settings after purchasing a new vehicle, and that changing the 
settings for testing purposes would likely not be most representative 
of most real-world driving situations.\185\ The automaker recommended 
that the Agency conduct a comparable fleet-wide study and use those 
findings for system settings to guide future test procedural changes.
---------------------------------------------------------------------------

    \185\ In a 2017-2019 study of nine focus groups involving 24 
participants (58 percent female and 42 percent male) from the 
Chicago, IL area, market research, and an online review focused on 
consumer perception of ADAS technologies, HATCI found that 
approximately 62 percent of consumers did not access or make changes 
to ADAS settings.
---------------------------------------------------------------------------

    Similar to HATCI, GM asserted that testing with a setting other 
than the factory default setting would not best represent real-world 
customer selection. In a 2016 study of FCWs, the automaker found their 
default setting (i.e., ``Far'') was utilized 59 percent of the time 
compared to 17 percent for the ``Medium'' setting and 15 percent for 
the ``Near'' setting.\186\ In 9 percent of cases, customers had turned 
the FCW system off even though a range of alert settings was available. 
From this, GM gleaned that the default setting aligns well with their 
customer preferences, and if customers had not been provided with a 
range of alert settings, more would have likely turned the FCW system 
off. Based on these findings, GM opined that utilizing the factory 
default setting for NCAP testing would challenge vehicle manufacturers 
to provide NCAP levels of performance at the setting choice most likely 
to be used by consumers while also limiting nuisance alerts.
---------------------------------------------------------------------------

    \186\ DOT HS 812 247, ``Large-Scale Field Test of Forward 
Collision Alert and Lane Departure Warning Systems,'' 2016.
---------------------------------------------------------------------------

Alternative Timing Settings
    Some respondents, like CAS, mentioned that selecting the setting 
that is ``least sensitive'' is most appropriate since it would provide 
consumers with a sense of the ``worst-case'' protection offered by the 
system, while Auto Innovators recommended that the Agency allow the 
manufacturer to decide the setting to be tested to promote flexibility 
with respect to system design. Like Intel, the group asserted that 
requiring a specific setting may impact the upper and lower bounds of 
system performance and sensitivity and thus affect customer 
satisfaction. Auto Innovators stated that by allowing automakers to 
specify the test setting, consumer acceptance would not be affected, 
and the Agency could still be assured that at least one setting meets 
system performance requirements.
Response to Comments and Agency Decisions
    The Agency has decided to adopt its March 2022 proposal for FCW 
timing settings in NCAP testing and will set FCW presentation timing to 
the middle (or next latest) setting during its AEB evaluations (see 
Figure 6). For FCW systems that have only two settings, as HATCI 
mentioned, the Agency will select the later setting for NCAP testing. 
NHTSA will apply a similar requirement to vehicles separately offering 
adjustments for AEB (e.g., early versus late intervention).
[GRAPHIC] [TIFF OMITTED] TN03DE24.005

    Although many commenters recommended that the Agency select the 
default setting for its AEB tests, generally citing that it is the 
setting most likely to be utilized in real-world driving, selecting the 
middle (or next latest) setting is most appropriate for NCAP's AEB 
testing program for several reasons. First, while there may be merit in 
selecting default settings for test evaluations, as noted in the 
Agency's initial proposal, harmonization with other third-party safety 
rating protocols, most notably Euro NCAP, is desirable whenever 
practicable. Also, it is a reasonable expectation that the setting most 
preferred or often used by consumers would (or rather should) be the 
default setting and that this setting should generally fall in the 
middle of the range of driver setting preferences that span either 
earlier or later alert settings. In essence, the default setting for 
FCW systems is expected to correspond to the middle alert setting. As 
such, NHTSA is not concerned that vehicle manufacturers may choose to 
alter FCW system designs to align current default settings to the test 
settings (i.e., middle), as GM asserted. In fact, the Agency encourages 
this. As AAA mentioned, this should limit designs that bias system 
response toward either earlier or later settings. Along these lines, 
the Agency has decided against choosing the latest setting for NCAP's 
AEB testing, as CAS suggested, even though it may identify worst-case 
performance. NHTSA does not want to encourage acceptable performance 
for only more aggressive settings that may be preferred by a limited 
number of drivers. Similarly, it has not opted to retain the most

[[Page 95974]]

conservative (or earliest) setting for NCAP's tests.
    This is not to suggest that manufacturers should provide other FCW 
or AEB system settings which will afford little to no benefit, nor 
should any other setting negatively impact the performance of FCW and/
or AEB. However, as NCAP is a consumer information program, NHTSA must 
provide comparable results in order for consumers to make informed 
purchasing decisions. Accordingly, it is selecting one timing setting 
for FCW and AEB systems, the middle (or next latest) setting, for 
NCAP's AEB testing. Also, for vehicles that have an ESC off switch, 
NHTSA will keep ESC engaged for the duration of the test.
    As previously mentioned, NHTSA has decided to evaluate FCW in 
tandem with CIB and DBS. To pass a test trial in the Agency's CIB or 
DBS evaluations that use LVD, LVM, and LVS scenarios, the SV must issue 
the required FCW signals (i.e., auditory and visual) prior to the onset 
of automatic braking (as defined by the instant SV deceleration reaches 
at least 0.15g). After the required FCW signals are issued, the SV's 
accelerator pedal will be fully released (at any rate) within 500 ms. 
Additionally, for DBS test conditions, manual braking will be imparted 
1.0  0.1 seconds after the complete, bimodal FCW is 
presented. Effectively, to perform well in the Agency's AEB 
evaluations, the vehicle must issue the FCW in a timely manner so that 
the accelerator pedal can be released, and the brake can be applied 
(either automatically or manually), with sufficient time to allow the 
vehicle to avoid contacting the POV. By integrating FCW assessments in 
this way, NHTSA expects, as GM opined with respect to default settings, 
that vehicle manufacturers will inherently strive to limit nuisance 
alerts during real-world driving for the FCW timing setting preferred 
by most drivers while also performing well in NCAP's AEB tests at this 
preferred setting. In essence, the Agency's effort to integrate testing 
should help to eliminate the concern expressed by Intel that TTC 
thresholds (and inherently nuisance alerts) may increase if the middle 
timing setting is selected for testing. Since the functionality of FCW 
and AEB will be assessed holistically, manufacturers should ultimately 
be afforded more flexibility with respect to system design. They may 
establish the upper and lower bounds of the FCW system's performance, 
deciding whether to either increase or reduce FCW TTCs to address 
customer satisfaction, and thus will effectively set the timing for the 
FCW setting to be tested (albeit the middle setting), as Auto 
Innovators requested. The resultant FCW and AEB system performance is 
markedly at their discretion.
    NHTSA also notes that, to receive credit for AEB, forward collision 
warning and automatic emergency braking technologies (i.e., FCW and AEB 
systems) must appear `Default ON' during each ignition/key cycle. While 
the Agency is not prohibiting a disabling function for these 
technologies in its NCAP evaluation, it does not expect that the 
testing requirements imposed herein should result in reduced consumer 
satisfaction. Instead, NHTSA expects drivers will adjust their 
vehicle's FCW and AEB system settings to meet their personal 
preferences instead of disengaging the systems altogether.
3. Additional FCW and AEB Test Scenarios and Conditions
a. Other FCW Scenarios or Test Conditions
    In its March 2022 RFC notice, NHTSA also requested comment on 
whether there were additional or alternative test scenarios or test 
conditions that it should consider incorporating into an updated FCW 
test procedure for NCAP. More specifically, the Agency sought comment 
on whether it should adopt tests for FCW that were more complex or at 
higher speeds compared to those tests/conditions proposed for CIB 
evaluations, and if so, whether or how NHTSA should amend the current 
FCW performance criteria (i.e., TTCs) and/or test scenario 
specifications.
Summary of Comments
    Intel, Honda, Auto Innovators, and GM recommended that the Agency 
not adopt any additional or alternative test scenarios or conditions 
for NCAP's FCW assessments. GM and Auto Innovators asserted that adding 
more complicated tests would increase test variation without providing 
meaningful performance distinctions, thus hampering consumers' ability 
to use results to compare performance across vehicles. Auto Innovators 
further stated that the current scenarios align well with crash data 
and other NCAPs. FCA also suggested that NHTSA retain the current test 
scenarios and did not offer suggested changes.
    In contrast, some respondents stated that the current FCW test 
conditions are not sufficient. Specifically, Adasky supported adopting 
tests for FCW (and CIB/DBS) that would assess system performance at 
higher speeds, at nighttime, and while turning. The commenter further 
stated that thermal cameras are currently available and can perform 
well under such conditions. NTSB also recommended incorporation of 
other test scenarios, including those involving cross traffic, vehicle 
cut-in situations, and additional targets (e.g., different types or 
orientations of vehicles, roadway hardware, such as crash attenuators, 
etc.).\187\ CAS encouraged the Agency to aim to optimize safety rather 
than simply encourage compliance.
---------------------------------------------------------------------------

    \187\ https://www.regulations.gov/comment/NHTSA-2021-0002-1530. 
See footnote 14.
---------------------------------------------------------------------------

Response to Comments and Agency Decisions
    As NHTSA has decided to integrate FCW testing into its AEB 
assessments as part of this upgrade to NCAP, and commenters were 
generally not supportive of retaining separate FCW assessments, the 
Agency will not incorporate any additional FCW test scenarios or test 
conditions at this time. However, the Agency currently has plans to 
conduct research that aligns with some of the commenters' 
recommendations, including nighttime AEB assessments and AEB testing 
with motorcycles and bicycles. NHTSA will continue to add scenarios to 
NCAP's roadmap in the future as research data becomes available, as 
detailed, objective test procedures are drafted, and as technologies 
mature to address the safety need.
b. Additional AEB Test Scenarios and Test Surrogates
    As mentioned previously, in its March 2022 RFC notice, NHTSA 
discussed findings from a 2019 IIHS study \188\ of 2009-2016 crash data 
from 23 states which suggested that the increasing effectiveness of AEB 
technology in certain crash situations is changing the rear-end crash 
problem. The study identified types of rear-end crashes in which 
striking vehicles involved in rear-end crashes were more likely to be 
equipped with AEB.\189\ These included rear-end crashes: (1) where the 
striking vehicle was turning relative to when it was moving straight; 
(2) when the struck vehicle was turning or changing lanes relative to 
when it was slowing or stopped; (3) when the struck vehicle was not a 
passenger

[[Page 95975]]

vehicle or was a special use vehicle relative to a passenger car; (4) 
on snowy or icy roads; or (5) on roads with speed limits of 112.7 kph 
(70 mph) relative to those with 64.4 to 72.4 kph (40 to 45 mph) speed 
limits.
---------------------------------------------------------------------------

    \188\ Cicchino, J.B. & Zuby, D.S. (2019, August), 
Characteristics of rear-end crashes involving passenger vehicles 
with automatic emergency braking, Traffic Injury Prevention, 2019, 
VOL. 20, NO. S1, S112-S118, https://doi.org/10.1080/15389588.2019.1576172.
    \189\ In this instance, over-represented means a higher 
frequency as a percentage for AEB-equipped vehicles versus non-AEB-
equipped vehicles on a normalized basis.
---------------------------------------------------------------------------

    Findings from the study suggested that tests used to evaluate the 
performance of AEB systems by the Agency's NCAP and other consumer 
information programs are influencing the development of countermeasures 
capable of minimizing the crash problems they were intended to address. 
However, the results also implied that, while current AEB systems are 
effective at addressing the most common rear-end crashes, they have not 
yet been optimized to address more atypical crashes where the SV is the 
striking vehicle.
    Given IIHS's findings, NHTSA requested comment on if (and how) it 
should alter its current AEB tests to not only address the ``changing'' 
rear-end crash problem, but also discourage system performance 
degradation in more typical crash situations, create unintended safety 
consequences, or adversely affect AEB use due to nuisance activations. 
The Agency also sought comment on future suggestions for AEB generally 
(i.e., beyond any near-term upgrade), including the adoption of 
additional AEB tests.
Summary of Comments
Capture Front Impact Events
    Rivian and NTSB stated the Agency should add ``cut-in'' scenarios, 
while CAS expressed that NHTSA should add ``lead vehicle maneuvers.'' 
Similar to Rivian and CAS, and in line with findings from its 2019 
study, IIHS suggested adding scenarios to capture lead vehicles that 
were changing lanes or turning, and tests where the lead vehicle is a 
non-passenger vehicle (e.g., medium- or heavy-duty truck) or motorcycle 
in order to improve the real-world effectiveness of AEB systems. 
Further, the organization suggested incorporating tests where the SV is 
turning (i.e., cross traffic) or travelling on roads with speed limits 
of 112.7 kph (70 mph) or more. IIHS explained, as the Agency 
acknowledged in its March 2022 RFC notice, that these situations were 
over-represented in real-world rear-end crashes involving an AEB-
equipped striking vehicle.\190\ Although the group acknowledged that 
the majority of the crash types mentioned were ``rare,'' those where an 
AEB-equipped vehicle struck a large truck or motorcycle accounted for 
approximately 40 percent of fatal rear-end crashes, thus suggesting 
that a test scenario simulating this crash type should be given 
thoughtful consideration for adoption. Adasky also supported AEB 
testing for turning scenarios.
---------------------------------------------------------------------------

    \190\ Cicchino & Zuby, 2019.
---------------------------------------------------------------------------

    Other commenters also favored incorporation of certain scenarios 
recommended by IIHS. Intel, for example, expressed support for 
including oncoming and crossing traffic test scenarios, similar to 
those recently adopted by Euro NCAP. IDIADA, along with several public 
commenters, mentioned the need for higher-speed assessments. Since 
testing becomes more difficult at higher speeds, the test laboratory 
suggested the Agency should incorporate a requirement that AEB systems 
must be operational up to 120 kph (74.6 mph). NTSB also favored the 
addition of cross-traffic scenarios, assessments for various vehicle 
types and orientations, and assessments for ``common roadway 
obstacles'' like ``roadway hardware'' (e.g., crash attenuators, 
concrete median barriers, etc.) that many vehicles do not currently 
detect.\191\
---------------------------------------------------------------------------

    \191\ Safety Recommendation H-20-1, currently classified 
``Open--Acceptable Response.''
---------------------------------------------------------------------------

    Finally, ZF Group supported adding an Emergency Steering Support 
(ESS) test, which it stated would assure vehicles provide steering (or 
added steering, in the case that the driver is already steering) to 
avoid a collision with the vehicle in front of it if there is not 
enough time for CIB to intervene effectively before a crash occurs. 
Examples of these scenarios include situations where vehicles are 
travelling at a high rate of speed and ``scenarios with low overlap.''
Capture Backing Events
    There were commenters, including TRC and Consumer Reports, who 
mentioned that the Agency should add rear automatic emergency braking 
(RAB). Consumer Reports suggested that the Agency adopt a rear cross-
traffic warning (RCTW) test.
Add Motorcycle or Other Powered 2-Wheeled Test Device
    Some commenters stated, like IIHS, that the Agency should adopt AEB 
test scenarios for motorcycle test devices. DRI proposed AEB testing 
with a motorcycle and/or scooter test device because: (1) ``motorcycle 
fatalities reached an all-time high'' in 2020,\192\ (2) the number of 
registered on-road motorcycles has been steadily increasing,\193\ and 
(3) NHTSA data shows that more than a quarter of motorcycle accidents 
involve rear-end crashes. FCW testing involving a motorcycle test 
device that was conducted by DRI showed that motorcycle detection rates 
varied widely compared to vehicle detection rates. The laboratory 
remarked that in many cases the SV either did not detect the motorcycle 
test device or detected it much later compared to the vehicle test 
device.
---------------------------------------------------------------------------

    \192\ According to DRI, there were 5,579 motorcycle fatalities 
in 2020 compared to 1,260 cyclist fatalities.
    \193\ IIHS data showed 4.2 million registrants in 2002 compared 
to 8.3 million in 2018.
---------------------------------------------------------------------------

    NTSB also supported AEB (and FCW) test assessments using a 
motorcycle test device.\194\ Similarly, Intel suggested the Agency 
consider incorporation of the test device used in Euro NCAP's powered 
two-wheeler (PTW) tests.
---------------------------------------------------------------------------

    \194\ Safety Recommendation H-18-29, currently classified 
``Open--Acceptable Response.''
---------------------------------------------------------------------------

Add Additional AEB Test Scenarios Based on Real-World Data
    Several commenters (Auto Innovators, BMW, FCA, and GM) specifically 
stated the Agency should not adopt any additional AEB test scenarios 
for NCAP unless real-world data supports their inclusion. FCA, GM, and 
Auto Innovators commented that current AEB systems have shown 
significant safety benefits in reducing rear-end crashes, such that 
according to GM and Auto Innovators, it is expected that adopting 
additional rear-end AEB test scenarios would likely offer little 
additional benefit.\195\ The two commenters stated that any additional 
AEB performance assessments should be centered around new crash types 
(depending on system capabilities) and supported by crash data trends. 
In addition, Auto Innovators asserted that potential new scenarios, 
such as those involving turning by an SV or lead vehicle, a lead 
vehicle lane change, or alternative test targets, may require vehicles 
to have cameras offering a larger field of view, additional radars 
(such as on the vehicle front corners), and algorithm changes to permit 
detection of the added targets. As such, the organization reiterated 
their opinion that crash data should dictate the need for these tests, 
which should be harmonized with Euro NCAP. CAS also mentioned that 
crash statistics should be considered when considering new tests for 
NCAP and suggested that market penetration of the various

[[Page 95976]]

system types (e.g., camera, radar) should guide priority for future 
testing.
---------------------------------------------------------------------------

    \195\ GM cited Leslie, A.J., Kiefer, R.J., Flannagan, C.A., 
Owen, S.H, & Schoettle, B.A. (2022). Analysis of the Field 
Effectiveness of General Motors Model Year 2013-2020 Advanced Driver 
Assistance System Features. UMTRl-2022-2 as a source of data 
considered for its conclusion.
---------------------------------------------------------------------------

    MEMA did not offer explicit suggestions for NHTSA to consider with 
respect to additional test scenarios that may be viable for inclusion, 
but the commenter did express support for the Agency's decision to 
``focus resources on emerging trends with the potential for future 
updates as the crash problem evolves.'' NTSB recommended that the 
Agency add tests (for all technologies) that assess higher speeds and 
increased complexities to evaluate ``advanced capabilities.'' State 
Farm and NYC DOT/NYC DCAS, Vision Zero Task Force also expressed 
support for higher test speeds in general and tests to reflect real-
world driving conditions and crashes.
Response to Comments and Agency Decisions
Capture Front Impact Events
    While the LVS, LVM, and LVD scenarios cover a substantial number of 
frontal impact events, there are other frontal impact scenarios that 
will not be directly assessed by NHTSA's NCAP testing as adopted in 
this final notice.
    Several commenters to the March 2022 RFC requested the addition of 
various intersection crash scenarios. The Agency agrees that, while the 
scenarios adopted for NCAP's AEB testing cover a large portion of 
crashes, there is a safety need for scenarios which cover intersection-
specific interactions, such as left turn across path and straight 
crossing path conditions. As mentioned in the NCAP Roadmap section, 
NHTSA plans to consider the inclusion of these scenarios in the future. 
Pending necessary research, the Agency may implement these additional 
scenarios for model year 2032 vehicles.
    Regarding AEB testing at higher speeds, NHTSA acknowledges that 
there is further safety potential to be realized by assessing CIB and 
DBS performance at speeds greater than those adopted for NCAP in this 
final notice. Indeed, NHTSA is aware, from a review of owner's manuals, 
that many vehicle manufacturers have equipped their vehicles with AEB 
systems that function at speeds much higher than those which will be 
evaluated by NCAP. Given the practical limitations of testing (e.g., 
safety of test personnel, vehicle and test equipment damage, etc.), 
test speeds are currently restricted. That said, the Agency expects 
that, with further evolution of test methods, vehicle systems, and 
equipment, test speeds could be increased in the future. The NCAP 
Roadmap currently incorporates a plan for further enhancement to the 
adopted AEB tests with evaluations beginning with model year 2033 
vehicles.
    At this time, NHTSA is not incorporating ESS testing as ZF Group 
suggested. The Agency must further study the capabilities and 
limitations of systems meant to support the driver during these 
maneuvers prior to incorporating assessments in its NCAP testing. The 
Agency may decide to include an evaluation of ESS systems in the 
future, particularly if it moves to evaluating performance at higher 
speeds than those adopted in this final decision notice.
    Additional recommendations included assessments using a variety of 
other objects as targets, such as crash attenuators, median barriers, 
and other roadway hardware. Large trucks were also proposed as possible 
impact targets for AEB evaluation. NHTSA does not have current research 
planned to evaluate these scenarios, but it may consider these, and 
other, assessments for the future.
Capture Backing Events
    The Agency will not include backing scenarios, such as those 
mitigated by RAB or RCTW, in NCAP's AEB testing at this time. As noted 
in the March 2022 notice, NHTSA is currently amending its RAB test 
procedure to account for earlier comments received. Once this work is 
completed, NHTSA hopes to add the related assessments to NCAP. As noted 
in the NCAP Roadmap section, NHTSA's plan is to evaluate RAB systems 
starting with model year 2028 vehicles.
Add Motorcycle or Other Powered 2-Wheeled Target
    In the March 2022 RFC notice, NHTSA stated that it was conducting 
additional research to evaluate vehicle AEB performance when 
approaching cyclists and motorcyclists. The Agency acknowledges, as did 
DRI, that motorcyclist fatalities have risen in recent years. Euro NCAP 
performs car-to-motorcyclist AEB testing under its AEB/Lane Support 
System (LSS) VRU Test Protocol.\196\ Specifications for the 
motorcyclist test device used in Euro NCAP's testing can be found in 
Motorbike Users Safety Enhancement (MUSE) Deliverable 2.1, Motorcyclist 
Target Specifications.197 198 The test device represents an 
average human adult motorcyclist on a motorcycle with dimensions based 
on average values of most registered motorcycles in Europe with a 
cylinder capacity of greater than 500 cc. Euro NCAP's AEB testing 
includes several scenarios, including rear stationary, rear braking, 
and front turn across path scenarios, all in daylight conditions.
---------------------------------------------------------------------------

    \196\ European New Car Assessment Programme (Euro NCAP) Test 
Protocol--AEB/LSS VRU systems, Implementation 2023. Version 4.5, 
December 2023.
    \197\ https://www.utac.com/wp-content/uploads/2023/04/MUSE-d2-1-motorcyclist-target-specifications.pdf.
    \198\ When published, Euro NCAP will replace the specifications 
provided with those in ISO/AWI 19206-5, ``Road vehicles--Test 
devices for target vehicles, vulnerable road users and other 
objects, for assessment of active safety functions--Part 5: 
Requirements for Powered Two-Wheeler targets''. At the time of this 
publication, ISO/AWI 19206-5 is Under Development in Stage 20.00 
(Preparatory, New project registered in TC/SC work programme).
---------------------------------------------------------------------------

    Preliminary results of NHTSA's motorcycle research testing using 
five vehicles have shown that many factors, such as lane position of 
the test device, lighting condition, and speed may influence vehicle 
braking performance, and there was no discernable pattern across the 
five vehicles tested. Further, some concerns were noted with the 
motorcyclist surrogate design used. Thus, NHTSA has further research 
underway and planned. A report summarizing this initial research, which 
was conducted in both daylight and darkness conditions, is expected to 
be available in 2024.
    NHTSA has expedited its follow-on research on AEB for other VRUs, 
namely bicyclists and motorcyclists. The Agency's research to develop 
and evaluate test procedures and surrogate targets for certain crash 
scenarios to address bicyclist and motorcyclist injuries in crashes 
with light vehicles is expected to be completed in 2024. As noted in 
the mid-term updates to NCAP in the NCAP roadmap finalized in this 
notice, NHTSA has included evaluation of AEB for mitigating crashes 
with bicyclists and motorcyclists starting with model year 2028 
vehicles.
c. Additional AEB Environmental Test Conditions
    In its March 2022 RFC notice, NHTSA noted that 51 percent of 
fatalities and 80 percent of MAIS 1-5 injuries caused by rear-end 
crashes occurred under daylight conditions. Further, nearly 92 percent 
of fatalities and 88 percent of injuries caused by such crashes 
occurred in clear weather.\199\ However, IIHS's rear-end crash study 
concluded that AEB-equipped vehicles are over-represented for crashes 
occurring in certain weather conditions, such as

[[Page 95977]]

snow and ice.\200\ Given these findings and the fact that the Agency's 
proposal for PAEB systems encompassed testing under less-than-ideal 
environmental conditions (specifically in darkness), NHTSA sought 
comment on whether it should pursue research to assess AEB system 
performance under less-than-ideal environmental conditions, and if so, 
what environmental conditions would be appropriate. This research would 
subsequently inform further updates to NCAP testing.
---------------------------------------------------------------------------

    \199\ Swanson, E., Foderaro, F., Yanagisawa, M., Najm, W.G., & 
Azeredo, P. (2019, August), Statistics of light-vehicle pre-crash 
scenarios based on 2011-2015 national crash data (Report No. DOT HS 
812 745), Washington, DC: National Highway Traffic Safety 
Administration.
    \200\ Cicchino, J.B. & Zuby, D.S. (2019, August), 
Characteristics of rear-end crashes involving passenger vehicles 
with automatic emergency braking, Traffic Injury Prevention. 2019, 
VOL. 20, NO. S1, S112-S118, https://doi.org/10.1080/15389588.2019.1576172.
---------------------------------------------------------------------------

Summary of Comments
    Commenters were generally in favor of the Agency conducting 
research to support inclusion of evaluations for different 
environmental conditions to encourage improved AEB performance. 
However, responses were varied, with suggestions spanning lighting 
conditions, road surface conditions, atmospheric conditions, etc. There 
were also a few commenters who did not support additional research into 
alternative environmental test conditions.
Lighting Conditions
    Several respondents, including ASC, Rivian, State Farm, and TRC, 
suggested that NHTSA add test scenarios that include different lighting 
conditions. ASC, CAS, Consumer Reports, and Uhnder favored assessments 
for dark, nighttime conditions as well as conditions that may cause 
glare or temporary driver blindness, such as those resulting from 
travelling directly toward the sun at dawn or dusk.
    Bosch, Adasky, and The Lidar Coalition commented that they support 
testing in low light conditions. Similar assertions were expressed by 
public commenters who mentioned that current AEB systems are 
problematic because they do not perform well in low light. The Lidar 
Coalition commented that testing in low light (with no overhead 
lighting and use of only the lower beam headlamps) is necessary because 
of performance differences observed for various sensor types. The 
commenter asserted that: cameras have high resolution but do not work 
well (i.e., cannot ``see'') in low light conditions; radar works well 
(i.e., can ``see'') in such conditions but lacks the resolution to 
detect slow-moving or stationary objects and to distinguish between 
objects that are close together; and lidar can both ``see'' in low 
light conditions and has high resolution, thus affording advantages 
where the other sensors independently cannot. Adasky stated that 
thermal cameras can perform well in dark conditions.
    Although Auto Innovators, in general, did not support the 
consideration of alternative environmental conditions to assess AEB 
systems currently, they did express modest support for adding low light 
evaluations in the near-term. However, the group, in addition to TRC, 
cautioned that the GVT would likely have to be modified to permit 
taillight illumination (TRC) and ``replicate the vehicle lighting or 
light reflection characteristics of real vehicles at night'' (Auto 
Innovators).
Road Surface Conditions
    Other commenters, including Rivian and CAS, recommended the Agency 
add test scenarios that evaluate performance on wet surfaces. CAS and 
Consumer Reports stated that assessments for icy conditions may also be 
appropriate, and IIHS suggested adding evaluations for ``surfaces with 
reduced friction.'' IIHS stated that crash data shows that AEB-equipped 
vehicles are over-represented in rear-end crashes on ``slippery roads'' 
such that encouraging AEB systems through testing to adjust brake force 
and intervene earlier on slippery roads compared to dry roads should 
promote improved AEB performance in the real world. IIHS further 
mentioned that their testing has shown that ``AEB systems initiate 
automated braking with the same force and time on `slippery' roads as 
on snowy roads,'' suggesting that only one test condition would be 
necessary. Advocates also supported incorporating testing for various 
roadway conditions.
Atmospheric Conditions
    Other respondents encouraged pursuing research to assess AEB 
performance in various atmospheric conditions that cause reduced driver 
visibility such as fog, smoke, ash, rain, hail, and snow (ASC and 
Uhnder). Uhnder remarked that fog alone causes more than 600 fatalities 
and over 16,300 injuries per year in the U.S.\201\ and yet digital 
radar, which is ``agnostic to lighting conditions'' and functions in 
``degraded visibility environments,'' is available and could provide 
safety benefits.
---------------------------------------------------------------------------

    \201\ ``Low visibility.'' Low Visibility--FHWA Road Weather 
Management. https://ops.fhwa.dot.gov/weather/weather_events/low_visibility.htm.
---------------------------------------------------------------------------

    Honda stated that NHTSA should first test in ``normal'' rain 
followed by fog, ``heavy'' rain, and snow. Although the automaker 
acknowledged that AEB performance may be limited in heavy rain and snow 
conditions due to tire traction, the company stated that assuring 
effective AEB functionality in conditions representing ``normal'' rain 
was reasonable and appropriate. State Farm also supported testing in 
snow and over a range of fog and rain conditions since sensors are 
known to operate differently. Likewise, Consumer Reports supported 
testing in heavy rain and snow as well as in low-visibility conditions, 
such as those found in fog and smoke, and Adasky supported assessments 
for heavy rain, snow, fog, and sleet. Adasky asserted that such 
conditions are ``typical and predictable;'' therefore, AEB systems 
should function reliably. Conversely, Auto Innovators explicitly stated 
that they did not support testing in heavy rain and snow because of the 
loss of tire traction previously mentioned by Honda.
    Several public commenters also expressed support for testing in 
inclement weather in general, stating current AEB systems are less 
reliable in such conditions. Additionally, Advocates stated that 
evaluating system performance under different weather and temperature 
conditions seems appropriate, since these are normal vehicle operating 
conditions. The group also stated that this testing will be essential 
to address inadequacies in system performance to assure the success of 
automated vehicles (AVs), as many of these technologies will serve as 
the building blocks for future AV development. Advocates, along with 
The League, suggested that NHTSA adopt those conditions that prove to 
be the most ``problematic'' for technologies during Agency research.
Use Real-World Data
    BMW, FCA, Auto Innovators, and GM stated that NHTSA should use 
real-world crash data to guide development of future test conditions.
    With respect to environmental conditions, Auto Innovators asserted 
that, if the Agency decides to pursue future research to assess AEB 
performance for varying environmental conditions, it should prioritize 
those conditions that occur more frequently in the real world before 
proceeding with assessments that simulate less frequently encountered 
conditions. The group cautioned that, at this time, the Agency should 
add only those conditions that are justifiable (i.e., will result in 
large safety benefits) because adding ``complex . . . variations in 
environmental conditions may require more sophisticated sensors and/or 
research and development that can

[[Page 95978]]

ultimately affect affordability.'' Likewise, BMW added that NHTSA 
should consider incorporating those environmental conditions that 
contribute to a higher percentage of accidents, critical injuries, and 
fatalities. That said, the manufacturer also stated they were not 
currently aware of any environmental condition that would be 
appropriate for inclusion. Similarly, GM remarked that real-world data 
shows that for those crashes with the highest Functional Years Lost 
that are relevant to the ADAS technologies the Agency is considering 
adopting in NCAP, the environmental conditions were typically clear and 
dry, such that there is not a strong need to include alternative 
assessments.
Repeatability and Reproducibility Concerns
    Several commenters (Auto Innovators, Bosch, GM, Intel, and TRC) 
cautioned NHTSA that repeatability and reproducibility is a concern for 
assessments involving environmental conditions. In fact, Intel, GM, and 
Auto Innovators stated they did not support the inclusion of less-than-
ideal environmental conditions in NCAP assessments for this reason. GM 
added that testing additional environmental conditions would be 
``inherently difficult and expensive to precisely control,'' and Auto 
Innovators stated that, except for possible low light conditions, it 
would add ``unnecessary test complexity.'' Both commenters further 
stated that the limited assessments conducted by NCAP would pale in 
comparison to the vast range of conditions and overall performance 
considerations that must be factored in during product design and 
development.
Add Changes to Test Conditions to NCAP Roadmap
    Some commenters (Auto Innovators, BMW, Bosch, and Consumer Reports) 
requested that NHTSA include any planned research into environmental 
conditions, along with expected completion dates, in the NCAP roadmap 
so that industry would have time to prepare for such changes.
Response to Comments and Agency Decisions
    At the moment, the Agency has decided to continue its research on 
AEB technologies. Further enhancements to AEB with additional scenarios 
and test conditions will be considered in the long-term updates to NCAP 
for the period 2029 to 2033.

V. Adding Pedestrian Automatic Emergency Braking (PAEB) Technology

    NHTSA is committed to improving the safety of VRUs and acknowledges 
the rapidly growing safety risk to pedestrians, with 7,388 pedestrians 
killed in 2021 and 60,577 injured in traffic crashes in the U.S.\202\ 
NHTSA notes that between 2012 and 2021, pedestrian fatalities rose from 
14 to 17 percent of all traffic fatalities. From 2020 to 2021 alone, 
pedestrian fatalities increased 13 percent, and pedestrian injuries 
increased 11 percent. PAEB has the potential to mitigate this risk, 
with a recent Swedish study finding that in daylight and twilight 
conditions, the presence of PAEB reduced pedestrian crash risk by 18 
percent.\203\ Given this substantial safety need, NHTSA is adopting 
PAEB evaluation as part of this NCAP upgrade.
---------------------------------------------------------------------------

    \202\ National Center for Statistics and Analysis. (2023, June), 
Pedestrians. (Traffic Safety Facts, 2021 Data. Report No. DOT HS 813 
458), Washington, DC: National Highway Traffic Safety 
Administration.
    \203\ Kullgren, A., Amin, K, & Tingvall, C. (2023) Effects on 
crash risk of automatic emergency braking systems for pedestrians 
and bicyclists, Traffic Injury Prevention, 24:sup1, S111-S115, DOI: 
10.1080/15389588.2022.2131403.
---------------------------------------------------------------------------

    By way of background, PAEB systems function like AEB systems but 
detect pedestrians instead of vehicles. PAEB systems use information 
from forward-looking sensors to warn the driver and actively apply the 
vehicle's brakes when a pedestrian (or, sometimes, cyclist, scooter-
rider, motorcyclist) is in the path of the vehicle and the driver has 
not acted to avoid the crash. Current PAEB systems typically use 
cameras to determine whether a pedestrian is in imminent danger of 
being struck by the vehicle. However, some systems use a combination of 
cameras, radars, and/or possibly lidar sensors.

A. Proposed Pedestrian Automatic Emergency Braking Test Procedures

    Most pedestrian crashes occur when a pedestrian is in the forward 
path of a driver's vehicle. Four common pedestrian crash scenarios 
include when the vehicle is:
    1. Heading straight and a pedestrian is crossing the road;
    2. Turning right and a pedestrian is crossing the road;
    3. Turning left and a pedestrian is crossing the road; and
    4. Heading straight and a pedestrian is walking along or against 
traffic.
    These four crash scenarios are defined as Scenarios S1-S4, 
respectively, by the Crash Avoidance Metrics Partnership (CAMP) Crash 
Imminent Braking (CIB) Consortium.\204\
---------------------------------------------------------------------------

    \204\ Carpenter, M.G., Moury, M.T., Skvarce, J.R., Struck, M. 
Zwicky, T.D., & Kiger, S.M. (2014, June), Objective tests for 
forward looking pedestrian crash avoidance/mitigation systems: Final 
report (Report No. DOT HS 812 040), Washington, DC: National Highway 
Traffic Safety Administration.
---------------------------------------------------------------------------

    NHTSA's draft research PAEB test procedure, published on November 
21, 2019, and referenced herein as the 2019 PAEB test procedure, 
included two scenarios, S1 and S4, which were identified when combined 
as the two most frequent, injurious, and fatal crash scenarios 
involving pedestrians in the U.S.205 206 Scenario S1 
represents a pedestrian crossing the road in front of the vehicle, and 
the S4 scenario represents a pedestrian moving with or against traffic 
along the side of the road in the path of the vehicle. Both test 
scenarios are expanded into multiple test conditions representing 
multiple pedestrian impact locations. A short description of each test 
condition (e.g., S1a, S4b) described in the 2019 PAEB test procedure is 
presented below for each test scenario (S1 and S4):
---------------------------------------------------------------------------

    \205\ Yanagisawa, M., Swanson, E., Azeredo, P., & Najm, W.G. 
(2017, April). Estimation of potential safety benefits for 
pedestrian crash avoidance/mitigation systems. (Report No. DOT HS 
812 400). Washington, DC: National Highway Traffic Safety 
Administration.
    \206\ 84 FR 64405 (Nov. 21, 2019).

 S1
[cir] S1a--The SV travels in a straight, forward direction at 16 kph 
(9.9 mph) or 40 kph (24.9 mph). An adult pedestrian mannequin crosses 
perpendicular to the vehicle's line of travel at 5 kph (3.1 mph). The 
SV encounters the mannequin walking from the right (i.e., the 
passenger's side of the vehicle) with 25 percent overlap of the 
vehicle.\207\ See Figure 7(a) for a scenario diagram.
---------------------------------------------------------------------------

    \207\ Overlap is defined as the percent of the vehicle's width 
that the pedestrian would traverse prior to impact if the vehicle's 
speed and pedestrian's speed remain constant.
---------------------------------------------------------------------------

[cir] S1b--The SV travels in a straight, forward direction at 16 kph 
(9.9 mph) or 40 kph (24.9 mph). An adult pedestrian mannequin crosses 
perpendicular to the vehicle's line of travel at 5 kph (3.1 mph). The 
SV encounters the mannequin walking from the right with 50 percent 
overlap of the vehicle. See Figure 7(b) for a scenario diagram.
[cir] S1c--The SV travels in a straight, forward direction at 16 kph 
(9.9 mph) or 40 kph (24.9 mph). An adult pedestrian mannequin crosses 
perpendicular to the vehicle's line of travel at 5 kph (3.1 mph). The 
SV encounters the mannequin walking from the right with 75 percent 
overlap

[[Page 95979]]

of the vehicle. See Figure 7(c) for a diagram.
[GRAPHIC] [TIFF OMITTED] TN03DE24.006

[cir] S1d--The SV travels in a straight, forward direction at 16 kph 
(9.9 mph) or 40 kph (24.9 mph). A child pedestrian mannequin crosses 
perpendicular to the vehicle's line of travel at 5 kph (3.1 mph). The 
SV encounters the child mannequin running from behind parked cars on 
the right with 50 percent overlap of the vehicle. See Figure 8 for a 
diagram.

[[Page 95980]]

[GRAPHIC] [TIFF OMITTED] TN03DE24.007

[cir] S1e--The SV travels in a straight, forward direction at 40 kph 
(24.9 mph). An adult pedestrian mannequin crosses perpendicular to the 
vehicle's line of travel at 8 kph (5.0 mph). The SV encounters the 
mannequin walking from the left (i.e., the driver's side of the 
vehicle) with 50 percent overlap of the vehicle. See Figure 9 for a 
diagram.
[GRAPHIC] [TIFF OMITTED] TN03DE24.008


[[Page 95981]]


[cir] S1f--The SV travels in a straight, forward direction at 40 kph 
(24.9 mph). An adult pedestrian mannequin moves perpendicular to the 
vehicle's line of travel toward the vehicle's right at 5 kph (3.1 mph), 
but it stops short (-25 percent overlap) of the SV's path. See Figure 
10(a) for a diagram.
[cir] S1g--The SV travels in a straight, forward direction at 40 kph 
(24.9 mph). An adult pedestrian mannequin crosses perpendicular to the 
vehicle's line of travel toward the vehicle's right at 5 kph (3.1 mph). 
The mannequin clears the SV's path (125 percent overlap). See Figure 
10(b) for a diagram.
[GRAPHIC] [TIFF OMITTED] TN03DE24.009

 S4
[cir] S4a--The SV travels in a straight, forward direction at 16 kph 
(9.9 mph) or 40 kph (24.9 mph). An adult pedestrian mannequin is 
stationary in front of the SV at 25 percent overlap. The mannequin is 
facing away from the SV on the right hand side of the road. See Figure 
11 for a diagram.
[cir] S4b--The SV travels in a straight, forward direction at 16 kph 
(9.9 mph) or 40 kph (24.9 mph). An adult pedestrian mannequin is 
stationary in front of the SV at 25 percent overlap. The mannequin is 
facing toward the SV on the right hand side of the road. See Figure 11 
for a diagram.

[[Page 95982]]

[GRAPHIC] [TIFF OMITTED] TN03DE24.010

[cir] S4c--The SV travels in a straight, forward direction at 40 kph 
(24.9 mph). An adult pedestrian mannequin is walking away from the 
approaching SV at 5 kph (3.1 mph), parallel to the flow of traffic. The 
mannequin is located on the right hand side of the road at 25 percent 
overlap. See Figure 12 for a diagram.
[GRAPHIC] [TIFF OMITTED] TN03DE24.011


[[Page 95983]]


    The proposed 2019 PAEB test procedure required that all testing 
take place during daylight hours with good atmospheric visibility and 
the use of posable pedestrian mannequins.
    As detailed in the March 2022 RFC Notice, the Agency proposed 
several changes to the 2019 PAEB test procedure involving the 
pedestrian mannequins, test conditions, test variants for SV speed, 
specified lighting conditions, and the number of test trials required 
to be conducted for each test variant. The RFC included the following:
    1. Use of articulated pedestrian mannequins with moving legs, 
instead of the posable child and adult pedestrian mannequins;
    2. SV test speeds from 10 kph (6.2 mph) to 60 kph (37.3 mph) in 
increments of 10 kph (6.2 mph) for each test condition (S1a, S1b, S1c, 
S1d, S1e, S4a, S4b, and S4c)
    3. PAEB evaluation in darkness lighting conditions with the 
vehicle's lower beam headlamps switched on, in addition to daylight 
conditions.
    The test matrix of the proposed PAEB evaluations is summarized in 
Table 17.

                                     Table 17--Test Matrix of Proposed PAEB Evaluations in the March 2022 RFC Notice
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                     Test speeds (kph (mph))
 Test cond.         Size        --------------------------------      Movement           Path origin      Overlap     Obstruction       Light condition
                                         SV          Pedestrian    classification                           (%)
--------------------------------------------------------------------------------------------------------------------------------------------------------
S1a........  Adult.............  10, 20, 30, 40,        5 (3.1)  Walk..............  Right.............        25  No...............  Daylight
                                  50, 60 (6.2,                                                                                        Darkness--Lower
                                  12.4, 18.6, 24.9,                                                                                    Beam.
                                  31.1, 37.3).
S1b........  Adult.............  10, 20, 30, 40,        5 (3.1)  Walk..............  Right.............        50  No...............  Daylight
                                  50, 60 (6.2,                                                                                        Darkness--Lower
                                  12.4, 18.6, 24.9,                                                                                    Beam.
                                  31.1, 37.3).
S1c........  Adult.............  10, 20, 30, 40,        5 (3.1)  Walk..............  Right.............        75  No...............  Daylight
                                  50, 60 (6.2,                                                                                        Darkness--Lower
                                  12.4, 18.6, 24.9,                                                                                    Beam.
                                  31.1, 37.3).
S1d........  Child.............  10, 20, 30, 40,        5 (3.1)  Run...............  Right.............        50  Yes..............  Daylight
                                  50, 60 (6.2,                                                                                        Darkness--Lower
                                  12.4, 18.6, 24.9,                                                                                    Beam.
                                  31.1, 37.3).
S1e........  Adult.............  10, 20, 30, 40,        8 (5.0)  Run...............  Left..............        50  No...............  Daylight
                                  50, 60 (6.2,                                                                                        Darkness--Lower
                                  12.4, 18.6, 24.9,                                                                                    Beam.
                                  31.1, 37.3).
S4a........  Adult (Facing       10, 20, 30, 40,              0  Stationary........  Right.............        25  No...............  Daylight
              Away).              50, 60 (6.2,                                                                                        Darkness--Lower
                                  12.4, 18.6, 24.9,                                                                                    Beam.
                                  31.1, 37.3).
S4b........  Adult (Facing       10, 20, 30, 40,              0  Stationary........  Right.............        25  No...............  Daylight
              Toward).            50, 60 (6.2,                                                                                        Darkness--Lower
                                  12.4, 18.6, 24.9,                                                                                    Beam.
                                  31.1, 37.3).
S4c........  Adult (Facing       10, 20, 30, 40,        5 (3.1)  Walk..............  Right.............        25  No...............  Daylight
              Away).              50, 60 (6.2,                                                                                        Darkness--Lower
                                  12.4, 18.6, 24.9,                                                                                    Beam.
                                  31.1, 37.3).
--------------------------------------------------------------------------------------------------------------------------------------------------------

B. Linking Proposed PAEB Test Scenarios With Real-World Crashes

    A review of pedestrian crashes from the 2011-2012 GES and FARS data 
sets where a light vehicle's front struck the pedestrian as the first 
event and there was no avoidance maneuver \208\ found that, on average, 
the S1 and S4 pre-crash scenarios represent approximately 10,431 (17 
percent) of the 62,917 real-world crashes involving pedestrians 
annually. The two pre-crash scenarios also account for 3,889 (30 
percent) of the 13,058 MAIS 2+ and 2,739 (40 percent) of the 6,770 MAIS 
3+ injured pedestrians. In these real-world crashes represented by S1 
and S4 scenarios, there were, on average, 2,016 fatal vehicle-to-
pedestrian crashes annually, representing 60 percent of the 3,337 fatal 
vehicle-pedestrian crashes.
---------------------------------------------------------------------------

    \208\ Yanagisawa, M., Swanson, E., Azeredo, P., & Najm, W.G. 
(2017, April), Estimation of potential safety benefits for 
pedestrian crash avoidance/mitigation systems (Report No. DOT HS 812 
400), Washington, DC: National Highway Traffic Safety 
Administration.
---------------------------------------------------------------------------

    More specifically, the researchers from the study found that for 
the S1 scenario, approximately 7,481 (12 percent) and 1,396 (42 
percent) real-world crashes involving pedestrian injuries and 
fatalities occurred annually, respectively. These resulted in, on 
average, 2,682 (21 percent) of MAIS 2+ injured pedestrians and 1,879 
(28 percent) of MAIS 3+ injured pedestrians yearly. For the S4 
scenario, approximately 2,950 (5 percent) and 620 (19 percent) of real-
world crashes involving pedestrian injuries and fatalities occurred 
annually, respectively. These resulted in, on average, 1,207 (9 
percent) of MAIS 2+ injured pedestrians and 860 (13 percent) of MAIS 3+ 
injured pedestrians yearly.
    The above figures include both daytime and nighttime crashes. 
Though the 2019 PAEB test procedure specified daylight conditions, 
there is a demonstrated safety need for the Agency and industry to 
jointly address nighttime pedestrian crashes in addition to those 
crashes that occur in the daytime. The Volpe study of 2011-2015 FARS 
and GES crash data showed that 75 percent of pedestrian fatalities and 
38 percent of pedestrian injuries occurred in dark conditions, 
including darkness illuminated by overhead lighting.\209\ A study of 
California, North Carolina, and Texas crash data revealed that 
pedestrians struck in the dark were five times more likely to be killed 
than those struck during the day.\210\ Various factors make low-light 
driving inherently more dangerous for pedestrians than driving during 
daylight hours, including a reduction in pedestrian visibility, night 
vision deterioration as an individual ages,\211\ an increased 
likelihood of driver drowsiness at nighttime,\212\ and an increased 
likelihood that both pedestrians and drivers are under the influence of 
drugs or alcohol in darkness compared to daylight.\213\ Furthermore, 
both IIHS and AAA have shown performance issues with current PAEB 
systems in dark conditions.\214\
---------------------------------------------------------------------------

    \209\ Yanagisawa, M., Swanson, E., Azeredo, P., & Najm, W.G. 
(2017, April), Estimation of potential safety benefits for 
pedestrian crash avoidance/mitigation systems (Report No. DOT HS 812 
400), Washington, DC: National Highway Traffic Safety 
Administration.
    \210\ Ferenchak, Nicholas N., Gutierrez, Risa E., & Singleton, 
Patrick A. (2022), Shedding light on the pedestrian safety crisis: 
An analysis across the injury severity spectrum by lighting 
condition, Traffic Injury Prevention, 23:7, 434-439, DOI: 10.1080/
15389588.2022.2100362.
    \211\ https://www.nsc.org/road/safety-topics/driving-at-night.
    \212\ https://www.nhtsa.gov/sites/nhtsa.gov/files/808707.pdf.
    \213\ https://deepblue.lib.umich.edu/bitstream/handle/2027.42/58726/99831.pdf?sequence=1&isAllowed=y.
    \214\ Cicchino, J.B (2022, February), Effects of automatic 
emergency braking systems on pedestrian crash risk, Insurance 
Institute for Highway Safety, https://www.iihs.org/api/datastoredocument/bibliography/2243.
---------------------------------------------------------------------------

    With regard to SV speeds, a review of 2011-2015 FARS and GES crash 
data sets showed that, for crashes where posted speed limit was known, 
8 percent of pedestrian fatalities and 36 percent of pedestrian 
injuries resulted from crashes that occurred on roadways with posted 
speeds of 40.2 kph (25 mph) and less (i.e., at speeds equivalent

[[Page 95984]]

to those covered by NHTSA's 2019 PAEB test procedure), whereas 38 
percent of fatalities and 76 percent of injuries occurred as a result 
of crashes on roadways with posted speeds of 56.3 kph (35 mph) and 
less.\215\ \216\ By adopting a higher maximum test speed than the one 
in the 2019 draft PAEB procedure, the Agency could address an 
additional 30 percent of fatalities and 40 percent of injuries. Since 
speeding was a reported factor in only 5 percent of the fatal 
pedestrian crashes and 2 percent of the injurious pedestrian crashes, 
NHTSA reasoned that the posted speed may correlate closely with the 
travel speed of the vehicle prior to impact with the pedestrian.\217\ 
\218\
---------------------------------------------------------------------------

    \215\ Swanson, E., Foderaro, F., Yanagisawa, M., Najm, W.G., & 
Azeredo, P. (2019, August), Statistics of light-vehicle pre-crash 
scenarios based on 2011-2015 national crash data (Report No. DOT HS 
812 745), Washington, DC: National Highway Traffic Safety 
Administration.
    \216\ The posted speed limit was either not reported or was 
unknown in 4 percent of fatal pedestrian crashes and 29 percent of 
pedestrian crashes that resulted in injuries.
    \217\ Swanson, E., Foderaro, F., Yanagisawa, M., Najm, W.G., & 
Azeredo, P. (2019, August), Statistics of light-vehicle pre-crash 
scenarios based on 2011-2015 national crash data (Report No. DOT HS 
812 745), Washington, DC: National Highway Traffic Safety 
Administration.
    \218\ In 4 percent of fatal and 11 percent of injurious 
pedestrian crashes, it was unknown or not reported whether speeding 
was a factor.
---------------------------------------------------------------------------

    Finally, roadway alignment and grade for real-world pedestrian 
crashes in Volpe's 2011-2015 data set were found to be comparable to 
those prescribed in the Agency's 2019 PAEB test procedures. Of those 
pedestrian crashes where roadway alignment was known, 94 percent of 
both fatal and injurious crashes occurred on a straight roadway, and 84 
percent and 88 percent of fatal and injurious pedestrian crashes, 
respectively, occurred on a level roadway.

C. PAEB Installation Rates and Research Tests

1. PAEB Installation Rates
    New vehicles equipped with PAEB systems, like those equipped with 
AEB systems, are currently broadly available. In the five years between 
model years 2018 and 2023, the percentage of the fleet fitted with 
standard PAEB systems rose from 19 percent to 91 percent. Not only has 
the presence of PAEB increased, but system performance has improved 
substantially. In model year 2019, 21 percent of vehicles tested by 
IIHS for PAEB performance received a ``Superior'' score, 27 percent 
received ``Advanced,'' 5 percent received ``Basic,'' and 4 percent 
received no credit. The remaining 44 percent did not have the 
technology available. By contrast, in model year 2022, only 12 percent 
of vehicles did not have PAEB available; 54 percent received 
``Superior'' ratings and 30 percent received ``Advanced'' ratings.\219\ 
\220\ The Agency has observed similar improvements in PAEB performance 
over this period during its research testing, as discussed in the 
sections to follow.
---------------------------------------------------------------------------

    \219\ IIHS's vehicle-to-pedestrian rating is a points-based 
assessment. A maximum of six points is possible, and points are 
assigned based on average amount of speed reduction afforded in each 
of three test scenarios, with bonus points awarded for vehicles that 
warn a driver at least 2.1 seconds prior to impact in a test 
condition similar to NHTSA's S1a.
    \220\ https://iihs.org/ratings/.
---------------------------------------------------------------------------

2. Model Year 2019 and 2020 Research Testing
    As described in the March 2022 RFC notice, the Agency conducted a 
series of tests on the same 11 model year 2019 and 2020 vehicles used 
in the CIB testing series to assess the operational range and 
performance of then-current PAEB systems. For the purpose of this 
study, the Agency used the 2019 PAEB test procedure but employed the 
articulating mannequins in lieu of posable mannequins and expanded the 
test procedure specifications to include higher vehicle test speeds of 
60 kph (37.2 mph) for the S1b, S1d, and S1e test conditions and 80 kph 
(49.7 mph) for the S4a and S4c conditions.\221\ For each test, the SV 
speed was incrementally increased to identify when each SV reached its 
operational limits and did not respond to the pedestrian mannequin. 
When no or late intervention occurred for a vehicle and test condition 
(i.e., combination of test scenario and speed), NHTSA repeated the test 
condition at a test speed that was 5 kph (3.1 mph) lower. This reduced 
speed defined the system's upper capabilities. NHTSA also chose to 
alter the lighting conditions from the 2019 PAEB test procedure 
specifications and conducted tests in both daylight and dark conditions 
using the vehicles' lower or upper beam headlamps as the only light 
source to illuminate the pedestrian mannequin. For most of the darkness 
tests, no overhead ambient light source was provided in either 
condition; however, for two of the model year 2020 vehicles, limited 
testing was also conducted using the vehicles' lower beam headlamps and 
overhead lights to investigate possible performance differences when 
using overhead lighting. These vehicles were subjected to PAEB 
conditions S1b, S1d, S1e, S4a, and S4c at test speeds of 16 kph (9.9 
mph) and 40 kph (24.9 mph).
---------------------------------------------------------------------------

    \221\ These test speeds represent the maximum test speeds 
potentially utilized for a given test condition. The actual speeds 
used for a given vehicle and test condition depended on observed 
PAEB system performance.
---------------------------------------------------------------------------

    The Agency's characterization testing showed that many model year 
2019 and 2020 vehicles were able to repeatedly avoid impacting the 
pedestrian mannequins at higher test speeds for S1 and S4 than those 
specified in the 2019 PAEB test procedure, and several vehicles 
repeatably achieved full crash avoidance at speeds up to 60 kph (37.3 
mph) or higher.\222\ These findings suggested that PAEB system 
performance at the time exceeded most of the testing requirements 
outlined in NHTSA's 2019 PAEB test procedure. Specific to testing in 
dark lighting conditions, PAEB system performance generally degraded in 
dark conditions compared to daylight conditions, results which align 
well with IIHS's system effectiveness study for 2017-2020 model year 
vehicles. IIHS found that although PAEB systems were associated with a 
32 percent reduction in pedestrian crashes occurring during daylight 
and a 33 percent reduction in pedestrian crashes for areas with 
artificial lighting during dawn, dusk, or at night, there was no 
evidence that PAEB systems were effective at nighttime without street 
lighting.\223\ With regard to overhead lighting, NHTSA's data suggested 
that a vehicle's PAEB system performs only slightly better with 
overhead lighting versus no overhead lighting.
---------------------------------------------------------------------------

    \222\ See Docket No. NHTSA-2021-0002-0002. There are embedded 
reports titled, ``PEDESTRIAN AUTOMATIC EMERGENCY BRAKING SYSTEM 
RESEARCH TEST'' for each of the 11 vehicle make/models.
    \223\ Cicchino, J.B (2022, February), Effects of automatic 
emergency braking systems on pedestrian crash risk, Insurance 
Institute for Highway Safety, https://www.iihs.org/api/datastoredocument/bibliography/2243.
---------------------------------------------------------------------------

3. Model Year 2021 and 2022 Research Testing
    Subsequently, NHTSA conducted a series of PAEB research tests to 
further assess current fleet performance.\224\ This testing, which 
generally aligned well with NHTSA's proposal for NCAP PAEB assessments, 
involved 12 model year 2021 and 2022 light vehicles and included PAEB 
testing for the following PAEB test conditions: S1a, S1b, S1c, S1d, 
S1e, S4a, S4b, and S4c. Testing was conducted under both daylight and 
darkness lighting conditions. For darkness conditions, NHTSA evaluated

[[Page 95985]]

the PAEB systems using lower beam headlamps, but for select conditions 
(S1b, S4a, and S4c), NHTSA also evaluated systems using upper beam 
headlamps. NHTSA utilized both adult and child articulated mannequins 
for this series. The goal of this research was to assess NHTSA's PAEB 
proposals (outlined in subsequent sections) and to gain further 
knowledge regarding capabilities of the current vehicle fleet. See 
Table 18 below for nominal test parameters used in this series of 
research tests.
---------------------------------------------------------------------------

    \224\ National Highway Traffic Safety Administration (2023, 
March). 2022 Light Vehicle Pedestrian Automatic Emergency Braking 
Test Summary. Washington, DC: National Highway Traffic Safety 
Administration.

                                    Table 18--Nominal Test Parameters for Model Year 2021-2022 PAEB Research Testing
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                         Test speeds (kph (mph))
Test  condition         Size        ---------------------------------      Movement        Path origin    Overlap      Obstruction      Light condition
                                             SV           Pedestrian    classification                      (%)
--------------------------------------------------------------------------------------------------------------------------------------------------------
S1a............  Adult.............  10, 20, 30, 40,         5 (3.1)  Walk.............  Right.........         25  No..............  Daylight.
                                      50, 60 (6.2,                                                                                    Darkness--Lower
                                      12.4, 18.6, 24.9,                                                                                Beam.
                                      31.1, 37.3).
S1b............  Adult.............  10, 20, 30, 40,         5 (3.1)  Walk.............  Right.........         50  No..............  Daylight.
                                      50, 60 (6.2,                                                                                    Darkness--Lower
                                      12.4, 18.6, 24.9,                                                                                Beam.
                                      31.1, 37.3).                                                                                    Darkness--Upper
                                                                                                                                       Beam.
S1c............  Adult.............  10, 20, 30, 40,         5 (3.1)  Walk.............  Right.........         75  No..............  Daylight.
                                      50, 60 (6.2,                                                                                    Darkness--Lower
                                      12.4, 18.6, 24.9,                                                                                Beam.
                                      31.1, 37.3).
S1d............  Child.............  10, 20, 30, 40,         5 (3.1)  Run..............  Right.........         50  Yes.............  Daylight.
                                      50, 60 (6.2,                                                                                    Darkness--Lower
                                      12.4, 18.6, 24.9,                                                                                Beam.
                                      31.1, 37.3).
S1e............  Adult.............  10, 20, 30, 40,         8 (5.0)  Run..............  Left..........         50  No..............  Daylight.
                                      50, 60 (6.2,                                                                                    Darkness--Lower
                                      12.4, 18.6, 24.9,                                                                                Beam.
                                      31.1, 37.3).
S4a............  Adult (Facing       10, 20, 30, 40,               0  Stationary.......  Right.........         25  No..............  Daylight.
                  Away).              50, 60 (6.2,                                                                                    Darkness--Lower
                                      12.4, 18.6, 24.9,                                                                                Beam.
                                      31.1, 37.3).                                                                                    Darkness--Upper
                                                                                                                                       Beam.
S4b............  Adult (Facing       10, 20, 30, 40,               0  Stationary.......  Right.........         25  No..............  Daylight.
                  Toward).            50, 60 (6.2,                                                                                    Darkness--Lower
                                      12.4, 18.6, 24.9,                                                                                Beam.
                                      31.1, 37.3).
S4c............  Adult (Facing       10, 20, 30, 40,         5 (3.1)  Walk.............  Right.........         25  No..............  Daylight.
                  Away).              50, 60, 65 (6.2,                                                                                Darkness--Lower
                                      12.4, 18.6, 24.9,                                                                                Beam.
                                      31.1, 37.3, 40.4).                                                                              Darkness--Upper
                                                                                                                                       Beam.
--------------------------------------------------------------------------------------------------------------------------------------------------------

    Like the Agency's AEB characterization research, testing for each 
PAEB scenario advanced from the lowest SV speed to the highest, with 
one initial trial conducted per test speed. If the SV did not contact 
the pedestrian mannequin during the initial trial for a given speed, 
the SV speed was increased by 10 kph (6.2 mph) and the next trial was 
conducted. This iterative process continued until the maximum test 
speed was reached.\225\ However, if the SV contacted the pedestrian 
mannequin for the initial trial conducted for test speeds of 20 kph 
(12.4 mph) or greater, and the SV speed at the time of impact was at 
least 50 percent less than the initial SV speed, the Agency performed 
up to four additional trials at the same SV speed.\226\ If the SV speed 
at the time of impact was 50 percent or greater than the initial SV 
speed, testing for that scenario ended. Relevant outcomes of this 
research are detailed throughout the applicable sections of this 
notice. Overall, vehicle performance in this test series was shown to 
have improved from the already relatively strong model year 2019-2020 
research test series.
---------------------------------------------------------------------------

    \225\ For S4 scenarios, after 60 kph (37.3 mph), the next, and 
final, test speed was 65 kph (40.4 mph).
    \226\ Vehicle-to-pedestrian contact at the lowest test speed of 
10 kph (6.2 mph) was noted but did not result in a cessation of 
testing at the next highest test speed.
---------------------------------------------------------------------------

D. Summary of Comments, Response to Comments, and Agency Decisions 
Pedestrian Automatic Emergency Braking Technology Inclusion in General

    Broadly, commenters were in favor of evaluating PAEB systems on new 
vehicle models. Many noted that pedestrian and cyclist fatalities are 
rising quickly relative to vehicle occupant fatalities. NSC presented 
data to show that in 2020, an estimated 6,721 pedestrians were killed, 
a 33-year high. On a local level, several city governments, 
transportation departments, and advocacy groups submitted pedestrian 
crash data from their own cities to support inclusion of PAEB 
evaluations in NCAP (Portland, OR; Minneapolis, MN; Boston, MA; 
Philadelphia, PA; New York, NY; and Bike Anchorage, among others). Data 
supplied by Bosch showed that an estimated 21,300 crashes with injuries 
and/or fatalities could be eliminated each year assuming full fleet 
penetration of PAEB.\227\ Bosch also presented data from IIHS that 
showed the presence of a PAEB system results in a 25 to 27 percent 
reduction in the risk of overall pedestrian crashes and a 29 to 30 
percent reduction in risk of injurious pedestrian crashes.\228\ 
Advocates stated that the research, analyses, and justification laid 
forth in the March 2022 RFC notice were detailed and sound, and CR 
suggested that the Agency should take action as quickly as possible 
given the rapid rise in crashes involving VRUs.
---------------------------------------------------------------------------

    \227\ https://www.regulations.gov/comment/NHTSA-2021-0002-3613. 
See attachment 4.
    \228\ Cicchino, J.B. (2022, February), Effects of automatic 
emergency braking systems on pedestrian crash risk, Insurance 
Institute for Highway Safety, https://www.iihs.org/api/datastoredocument/bibliography/2243.
---------------------------------------------------------------------------

    NSC also noted that VRU protection is one of the ``largest gaps'' 
in the current NCAP. In general, commenters strongly favored a paradigm 
shift in NHTSA's vehicle ratings program. NCAP ratings currently 
address safety of the vehicle occupants only; however, many wished to 
see the safety information provided expand beyond the vehicle and 
extend to VRUs in the wider community. Some individuals indicated that 
they do not feel safe as a VRU. Commenters often stated that only 
vehicle purchasers (i.e., not VRUs) can choose vehicles that are 
designed to protect VRUs. Aptiv stated that vehicle-to-VRU scenarios 
should be treated with greater stringency than vehicle-to-vehicle 
scenarios because of the risk of severe injury and/or fatality to those 
outside of the vehicle. NTSB stated it has previously called on NHTSA 
to implement performance tests for evaluating PAEB systems \229\ and to 
incorporate them into NCAP,\230\ noting that these actions might 
incentivize vehicle manufacturers to include and improve PAEB systems.
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    \229\ Safety Recommendation H-18-42.
    \230\ Safety Recommendation H-18-43.

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[[Page 95986]]

    Comments received in response to NHTSA's proposal are summarized 
below, along with the corresponding Agency decision.
1. Test Conditions for S1 and S4, Including False Positive Assessments 
S1f and S1g and Varying Lighting Conditions
    Because the Agency is committed to reducing test burden whenever 
appropriate, NHTSA proposed to include Scenarios S1a-e and S4a-c in its 
upcoming NCAP assessment but sought comments on the necessity of 
running each test condition to adequately address the safety problem. 
Further, NHTSA did not propose to include PAEB false positive test 
conditions (i.e., S1f and S1g) in NCAP in its March 2022 notice. 
However, it requested comment on whether the omission of these test 
conditions is acceptable.
    In addition to performing PAEB testing in daylight conditions, 
NHTSA's proposal for PAEB in NCAP included executing scenarios S1a-e 
and S4a-c in dark lighting conditions to simulate nighttime pedestrian 
encounters. As detailed in the RFC notice and by many commenters, 
nighttime travel is risky for VRUs.\231\ In 2021, most pedestrian 
fatalities occurred in the dark (77 percent).\232\ NHTSA sought comment 
on this approach.
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    \231\ As detailed in the March 2022 RFC notice, Volpe's 2011-
2015 FARS data set showed that 36 percent of pedestrian fatalities 
occurred in the dark with no overhead lights.
    \232\ National Center for Statistics and Analysis. (2023, June), 
Pedestrians. (Traffic Safety Facts, 2021 Data. Report No. DOT HS 813 
458), Washington, DC: National Highway Traffic Safety 
Administration.
---------------------------------------------------------------------------

Summary of Comments
    Several commenters stated that the Agency should move forward with 
the proposed PAEB test conditions. Specifically, Uhnder, CAS, FCA, AAA, 
ASC, Intel, and one individual submitted comments in support of moving 
forward with test conditions S1a-e and S4a-c. CAS and the individual 
commenter noted that reducing test burden without empirical evidence 
supporting this decision will not adequately address the safety 
problem. AAA asserted that inclusion of the proposed test plan would 
``characterize system response to variations of kinematic 
characteristics realistically encountered in the naturalistic 
environment.'' To reduce test burden while maintaining real-world 
relevance and test stringency, Intel reasoned that, since these test 
conditions are all well-known to industry and have been defined in 
existing international regulations, NHTSA could require OEMs to self-
report predicted performance data and the Agency could ``spot-check'' 
results, reflecting Euro NCAP's methodology. As an alternative approach 
to reduce burden, Toyota posed that NHTSA could determine a subgroup of 
certain scenarios (and/or test speeds) that will ensure adequate 
performance across a range of conditions/speeds and run this subgroup 
of tests rather than the full battery. Instead of reducing the test 
matrix at this time, Uhnder and ASC suggested NHTSA could re-evaluate 
the necessity for each test condition on a regular basis; at that time, 
tests could be reduced if there is no longer a need.
    Several other commenters provided general input on which test 
conditions should be selected for inclusion. Mercedes-Benz and 
Advocates noted that test conditions selected should reflect real-world 
conditions and needs, and those needs should be supported by 
statistically significant data. Advocates added that NHTSA should 
select test conditions which give the Agency confidence that the system 
will operate as intended by the manufacturer.
    Some commenters recommended specific reductions for the proposed 
test conditions. Pertinent comments are summarized below.
S1 Test Conditions
    Many commenters requested the Agency reduce the test plan proposed 
for the S1 scenario. HATCI, Honda, Auto Innovators, MEMA, GM, and BMW 
supported removal of S1b, a test condition involving an adult-sized 
pedestrian mannequin entering the roadway from the nearside with 50 
percent overlap of the vehicle at point of contact. HATCI's rationale 
for removal of S1b was that the 25 percent (S1a) and 75 percent (S1c) 
overlap conditions address the 50 percent condition adequately; 
therefore, the S1b test condition would be redundant. Bosch, Honda, 
MEMA, BMW, and Auto Innovators agreed with HATCI's sentiments. GM 
supported this rationale for a pass/fail scoring system; however, the 
manufacturer recommended that the Agency adopt a wider range of test 
conditions if NCAP ratings would be assigned according to a points-
based system. Some of the same commenters supporting a reduction in the 
test matrix for the S1 scenario (Honda, Auto Innovators, BMW) asserted 
that S1c should also be removed because they considered the S1a (25 
percent overlap) condition to be the most stringent test case. TRC also 
stated that S1c was redundant and could be removed for similar reasons; 
the laboratory did not mention removal of S1b. Mercedes-Benz supported 
harmonization with international test protocols for the PAEB crossing 
conditions whenever possible. Similarly, Bosch recommended 
harmonization with Euro NCAP's PAEB evaluation.
S4 Test Conditions
    For the S4 scenarios, Mercedes-Benz, Auto Innovators, Subaru, and 
BMW recommended NHTSA remove both S4a and S4b from its test plan. S4a 
and S4b both involve the use of a stationary pedestrian mannequin 
situated on the nearside of the road at a 25 percent overlap facing 
away from (S4a) or towards (S4b) the SV. Mercedes-Benz was unsupportive 
of the use of stationary targets, citing data from three resources: a 
Volpe study, which did not identify any stationary scenarios; \233\ an 
ISO standard, which does not prescribe the use of any stationary 
pedestrian tests due to low occurrence; \234\ and a Mercedes-Benz study 
of German In Depth Accident Study (GIDAS) data, which revealed that 
only 4 percent of pedestrians struck were stationary.\235\ Subaru 
recommended that NHTSA focus on the S4c test condition, showing FARS 
data from 2016-2020 that indicated 61% of pedestrians struck alongside 
a roadway were walking in the direction of traffic. Auto Innovators, 
Honda, GM, and BMW reasoned that S4b is redundant with S4a since the 
only difference is the direction of the pedestrian, but Auto Innovators 
and BMW went on to state, similar to Subaru, that S4a and S4b may both 
be eliminated since S4c scenarios are more common in the real world. 
MEMA, Bosch, and Toyota were in favor of including either S4a or S4b, 
but not both, with Bosch encouraging the Agency to harmonize with the 
corresponding PAEB test procedures used by Euro NCAP. NACTO did not 
offer support for specific in-path condition, but the group noted that 
it is important for PAEB systems to detect stationary pedestrians.
---------------------------------------------------------------------------

    \233\ Carpenter, M.G., Moury, M.T., Skvarce, J.R., Struck, M. 
Zwicky, T.D., & Kiger, S.M. (2014, June), Objective tests for 
forward looking pedestrian crash avoidance/mitigation systems: Final 
report (Report No. DOT HS 812 040), Washington, DC: National Highway 
Traffic Safety Administration.
    \234\ ISO/CD 19237:2017.
    \235\ NHTSA-2021-0002-3847.
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Removal of Select Test Conditions
    IIHS took a different approach in its comments, stating that its 
consumer information program includes scenarios S1a, S1d, and S4c. S1d 
is a test scenario in which a child-sized pedestrian

[[Page 95987]]

mannequin enters the roadway from the nearside behind parked vehicles 
with 50 percent overlap of the vehicle. IIHS recommended that NHTSA 
focus on expediting rulemaking efforts for AEB/PAEB, stating that model 
year 2021 vehicles examined by the group performed exceedingly 
well.\236\ Should the Agency pursue PAEB rating in NCAP, the group 
suggested removal of the three tests that it currently conducts (S1a, 
S1d, and S4c) to reduce unnecessary test burden, indicating that any 
consumer confusion could be mitigated by explaining that the two 
programs are meant to be complementary.
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    \236\ https://www.regulations.gov/comment/NHTSA-2021-0002-4068. 
``Of 186 systems on vehicles from 29 automakers that we examined in 
2021, 46% were superior, 34% were advanced, 5% were basic, 1% 
received no credit, and 13% were not available with pedestrian 
detection. Of those rated advanced or superior, 68% were standard 
equipment rather than optional features. Systems receiving a 
superior rating can avoid or substantially reduce the impact speed 
in almost all, if not all, three scenarios.''
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False Positive Test Conditions (S1f and S1g)
    Regarding false positive test conditions S1f and S1g, most 
commenters suggested that false positive tests should not be conducted 
in NCAP for PAEB. Bosch, Toyota, Honda, FCA, AAA, GM, Auto Innovators, 
BMW, and IIHS were not in favor of including S1f and S1g. Toyota 
submitted data to show that, due to tolerance overlap between the 
``off'' and ``on'' conditions, there is a risk of leaving PAEB off when 
it should remain on. Bosch, Auto Innovators, Honda, and BMW echoed this 
sentiment. For instance, Bosch noted the unpredictability of 
pedestrians and suggested that it is safer for a vehicle to stop if 
there is a chance that the pedestrian will enter the vehicle's path. 
Bosch suggested that NHTSA should be cautious not to incorporate 
scenarios that may prompt a vehicle to continue driving when a 
pedestrian may continue into the vehicle's path, as this may erode 
consumer confidence and trust in PAEB systems. Similarly, AAA stated 
that automakers should not be ``pressured to minimize false positives 
at the possible expense of reduced system efficacy.'' Along these 
lines, FCA asserted that designing for S1f and S1g conditions may 
negatively affect tuning and calibration. IIHS and GM both noted that 
stakeholders could collect data on false activations by monitoring 
real-world field performance data. They claimed that this will be more 
useful since the test conditions outlined by the Agency will not 
address the full variety of situations in which false activations may 
occur in the field. They also noted that manufacturers have a vested 
interest in minimizing false positives to improve customer 
satisfaction.
    Conversely, a few commenters were in favor of adding false positive 
test conditions S1f and S1g to the battery of NCAP PAEB tests. TRC 
noted that vehicles still brake during these false positive tests, and 
thus reasoned that manufacturers may continue to increase system 
robustness if included in NCAP. Rivian stated that false positive 
conditions should be included since these situations occur in the field 
and braking unnecessarily and on short notice can contribute to the 
rear-end crash problem. CAS cited concern for various groups of VRUs, 
such as children, compromised adults, and animals, in its support for 
false positive testing. Like Bosch (above), CAS mentioned that these 
VRUs may first stop at the edge of the roadway but then continue 
crossing or reverse direction. Unlike Bosch, however, CAS suggested 
that the Agency should conduct false positive testing to ensure PAEB 
systems include additional safety margins and provide adequate 
protection. Adasky stated that false positive results serve as an 
indication of a lack of system robustness and are therefore important 
to include. Aptiv also noted that fused sensor technology should 
minimize false positive activation. Intel was not opposed to the 
inclusion of scenarios S1f and S1g, but it also suggested that test 
parameters and criteria should be reviewed carefully. In Intel's 
opinion, warnings or short braking intervals may be acceptable to the 
driver since the miss distance for the false positive scenarios is 
relatively small. The group noted that this especially holds true for 
cases where the SV speed is high and the pedestrian is crossing the 
path, as the driver may not be sure that there is enough time for the 
pedestrian to cross safely. Intel stated it would like to see the miss 
distance reviewed and road markings considered.
Overall Need for PAEB Testing in Darkness Lighting Conditions
    Respondents from a variety of backgrounds approved of NHTSA's 
decision to conduct PAEB testing in dark lighting conditions. Many 
suggested that PAEB testing in dark lighting conditions was critical 
given the real-world safety problem. Generally, commenters were 
concerned about the current effectiveness of PAEB systems, citing 
studies that showed PAEB systems do not work as well in low light as 
they do in daylight. These groups and individuals reasoned that NHTSA 
must evaluate PAEB systems in dark conditions to encourage improvements 
in system performance.
    Auto Innovators and HATCI requested more information from NHTSA 
regarding PAEB test procedures in dark lighting conditions and real-
world nighttime crash conditions. Auto Innovators asked that NHTSA more 
clearly define nighttime parameters in its test procedure so that test 
repeatability could be guaranteed. Should NHTSA decide not to harmonize 
with Euro NCAP nighttime test procedures, HATCI reasoned that NHTSA 
should study U.S. areas prone to nighttime crash events to determine 
precise lux levels and other environmental conditions which might be 
representative of these high-incident areas. These specifications 
should then be incorporated into NCAP's test procedures, increasing 
test repeatability. The automaker provided pedestrian-related crash 
data gathered from Ann Arbor, MI, including recorded lux measurements 
for areas with the highest pedestrian crash risk. Similarly, Advocates 
suggested that NHTSA evaluate real-world data to determine which kinds 
of crashes are occurring most frequently in low light and dark 
conditions. The group mentioned that this data could help inform 
testing practices and may also suggest that other technologies, 
including LDW/LKA and BSW/BSI, should be evaluated under nighttime 
conditions as well.
    Two commenters, Toyota and Auto Innovators, asserted there was not 
a need for the Agency to conduct condition S1d runs at night. Both 
groups referred to an accident analysis that showed the percentage of 
pedestrian impacts with vehicle obstacles present is low and therefore 
suggested that NHTSA eliminate the nighttime assessment of this 
scenario.
Response to Comments and Agency Decisions
    The Agency plans to adopt specific test conditions from the S1 and 
S4 test scenarios included in its 2019 PAEB test procedure for NCAP's 
PAEB assessments. In particular, the Agency is adopting S1a, S1b, S1d, 
and S1e for crossing path conditions and S4a and S4c for in-path 
conditions. NHTSA will perform assessments for each of these test 
conditions in both daylight and darkness.
    The Agency recognizes that this decision conflicts with IIHS's 
request that NHTSA consider removal of select test conditions, notably 
S1a, S1d, and S4c, because they are performed by IIHS. While NHTSA 
suggests that consumers review all available,

[[Page 95988]]

reputable safety information to make purchasing decisions, the Agency's 
safety information program should be informative enough to stand alone. 
Since NHTSA cannot guarantee that any information currently available 
from other entities will remain available in the same capacity 
indefinitely, the Agency should not omit certain test conditions simply 
because comparable ratings information is currently provided by another 
consumer program. However, NHTSA has decided to omit a few of the test 
conditions it proposed in its RFC from NCAP's final PAEB test matrix 
based on comments received and recent Agency research.
S1 Test Conditions
    As noted earlier, in 12 percent of pedestrian crashes involving 
injuries and 42 percent of crashes involving pedestrian fatalities, a 
light vehicle is traveling straight while a pedestrian enters the 
vehicle's path from either the left or right side.\237\ These real-
world crashes can be represented by the S1 crossing path scenario. More 
specifically, the S1a-c test conditions involve an adult pedestrian 
walking into the roadway and into the SV's path from the right side. 
For each of these three S1 test conditions, S1a, S1b, and S1c, the 
pedestrian mannequin begins its crossing maneuver at different times 
prior to collision, thus resulting in 25, 50, and 75 percent overlap, 
respectively, with the vehicle's front end.
---------------------------------------------------------------------------

    \237\ Yanagisawa, M., Swanson, E., Azeredo, P., & Najm, W.G. 
(2017, April), Estimation of potential safety benefits for 
pedestrian crash avoidance/mitigation systems (Report No. DOT HS 812 
400), Washington, DC: National Highway Traffic Safety 
Administration.
---------------------------------------------------------------------------

    Several commenters suggested that NHTSA include the 25 and 75 
percent overlap assessments only (i.e., S1a and c, respectively). Euro 
NCAP assesses vehicles in these two test conditions, represented by 
their Car-to-Pedestrian Nearside Adult 25 percent (CPNA-25) and Car-to-
Pedestrian Nearside Adult 75 percent (CPNA-75) conditions, and does not 
perform a CPNA test at 50 percent overlap. Commenters stated that the 
25 and 75 percent overlap conditions sufficiently cover the 50 percent 
overlap condition, making the S1b assessment superfluous. However, this 
assertion was not found to be accurate in the Agency's model year 2021-
2022 research testing. One vehicle contacted the pedestrian mannequin 
in the S1b test at 60 kph (37.3 mph) but did not contact the mannequin 
for any of the other test speeds included for either the S1a or S1c 
conditions during daylight testing. Thus, if the Agency had not 
conducted S1b for this vehicle, the failure would not have been 
captured. Additionally, for a second vehicle, contact was observed at 
50 kph (31.1 mph) in the S1b test conducted during daylight but was not 
observed until 60 kph (37.3 mph) in the S1a test. Similarly, during 
darkness testing with lower beam headlamps, three vehicles subjected to 
the S1b test condition contacted the pedestrian mannequin at 50 kph 
(31.1 mph), whereas contact was not observed for the S1a test condition 
until 60 kph (37.3 mph). Given these findings, it is beneficial to 
adopt the S1b test condition.
    The Agency is also retaining the S1a condition from its proposal 
because doing so should ensure the system has an adequate operational 
field of view and is able to identify pedestrians that are not at the 
center of the travel path. In addition, this test condition was 
generally found to be more stringent, as several commenters suggested, 
with the only exceptions observed being the two vehicles previously 
mentioned for the S1b test. Although IIHS also performs tests that 
correspond to NHTSA's S1a test, adopting this test condition for NCAP 
would be advantageous at this time given the results observed during 
the Agency's model year 2021-2022 research testing. Specifically, only 
four of the twelve vehicles tested were able to avoid contacting the 
pedestrian mannequin for every test speed assessed for the S1a test 
condition in daylight. This number was reduced to two during darkness 
testing with lower beam headlamps, with performance degradation 
generally beginning around 40 kph (24.9 mph). While these results show 
this condition may be challenging for current PAEB systems, they also 
show that passing performance is practicable for all adopted test 
speeds.
    Although NHTSA has decided to retain the S1a and S1b test 
conditions for NCAP PAEB testing, it does not plan to adopt the S1c 
test condition (i.e., Euro NCAP's CPNA-75 test). Because of the larger 
amount of overlap at the point of impact (75 percent) for the S1c 
condition, the vehicle is afforded an increased amount of time for the 
PAEB system to sense and react to the crossing pedestrian. NHTSA's 
model year 2021-2022 research testing showed that vehicles which 
contacted the pedestrian mannequin in the S1c test condition also 
contacted the mannequin in either S1a or S1b at the same speed or at a 
lower speed for both daylight and darkness testing. Therefore, the 
Agency agrees with those commenters that stated that S1c is the least 
stringent of the S1a-c crossing path test conditions. The Agency also 
acknowledges Toyota's recommendation that it should seek to reduce test 
burden in situations where it can remove a test condition and still 
ensure adequate performance across a range of conditions. Since system 
performance observed for the 75 percent overlap condition appears to be 
sufficiently addressed by the 25 percent and 50 percent overlap 
conditions, NCAP sees no need to also adopt the S1c test condition.
    The Agency has also decided to adopt the S1d test condition, which 
was particularly challenging for vehicles in the Agency's recent 
testing series. Because the child mannequin emerges from behind an 
obstruction (parked vehicle along the SV's path), the SV's PAEB system 
has less time to detect and react to the pedestrian. No vehicle out of 
the 12 tested in the model year 2021-2022 test series achieved full 
avoidance for every test speed assessed for this test condition in 
either daylight or dark lighting condition. For daylight testing, four 
vehicles contacted the pedestrian mannequin in the first trial for the 
60 kph (37.3 mph) test at a speed less than 50 percent of the initial 
speed (less than 30 kph, or 18.7 mph), but none demonstrated full 
avoidance in at least three of the four retrials. However, three 
vehicles were able to repeatedly avoid contact up to and including 50 
kph (31.1 mph). An additional vehicle contacted the pedestrian 
mannequin at 10 kph (6.1 mph) in daylight but avoided contacting again 
until the 60 kph (37.3 mph) test was conducted. Most often, for the 
other vehicles in the test series, performance degradation at higher 
speeds began occurring around 40 kph (24.9 mph) during the daylight 
runs. During darkness testing, no vehicle was able to achieve full 
avoidance for three or more trials at test speeds of 40 kph (24.9 mph) 
or greater. Five vehicles exhibited contact with the pedestrian 
mannequin at the lowest test speed of 10 kph (6.1 mph). For the 
remaining seven vehicles, four contacted the mannequin with speed 
reductions of less than 50 percent at an SV initial speed of 40 kph 
(24.9 mph), two models contacted at 30 kph (18.6 mph), and one model 
contacted at 20 kph (12.4 mph).
    While subpar performance was observed for the S1d test condition, 
there is merit in including it in NCAP's final PAEB test matrix for 
both daylight and dark lighting conditions. Several commenters 
mentioned that the real-world occurrence rate of this condition is 
relatively low in comparison to some of the other adopted test 
conditions, particularly with respect to the darkness variant. However, 
NHTSA notes that because of the shorter daylight time in fall and 
winter, it is possible for

[[Page 95989]]

children to be walking after events, such as an evening soccer 
practice, in relatively dark lighting conditions. It is important to 
adopt the S1d condition for NCAP testing since it involves a child 
pedestrian and is one with which current vehicles especially struggle. 
NHTSA received a substantial number of comments in response to the RFC 
regarding child safety.
    Finally, NHTSA will adopt the test scenario S1e, which represents 
an adult pedestrian running into the vehicle's path from the far, or 
left-hand, side. NHTSA received few comments regarding the 
applicability of this test condition. During the Agency's model year 
2021-2022 daylight testing series, two vehicles achieved full crash 
avoidance at all test speeds in the S1e condition, and an additional 
two only contacted the pedestrian mannequin during the 60 kph (37.3 
mph) test speed. Nearly the same observations were made for the 
Agency's lower beam headlamp darkness testing; two vehicle models 
avoided contact with the pedestrian mannequin at all assessed test 
speeds, and one additional model only contacted the mannequin at the 60 
kph (37.3 mph) test speed. Several vehicles that only experienced 
contact at higher test speeds during the S1b condition (where the 
pedestrian mannequin approaches the test vehicle from the right side at 
50 percent overlap) did not perform as well for S1e, when the 
pedestrian entered at a faster speed from the left-hand side with the 
same overlap at the point of impact (50 percent). This was true for 
both daylight and darkness testing with lower beams.
    It is critical to assess PAEB performance when the pedestrian is 
crossing from the left side as well as from the right, and while both 
walking and jogging. As several vehicles were able to perform well when 
subjected to the S1e condition in daylight, and two vehicles were able 
to provide complete avoidance for all test speeds in darkness with 
lower beams, NHTSA will include the S1e condition in NCAP at this time.
S4 Test Conditions
    NHTSA has decided to include scenarios S4a and S4c in NCAP's 
updated test matrix for both lighting variants. The in-path scenario, 
S4, which includes test conditions S4a, S4b, and S4c, represents a 
pedestrian standing alongside the roadway facing away from the vehicle 
(S4a) or towards the vehicle (S4b), or walking along with traffic away 
from the vehicle on the side of the roadway with a 25 percent overlap 
(S4c). Overall, the S4 scenario comprises 5 percent of pedestrian 
crashes involving injuries and 19 percent of pedestrian 
fatalities.\238\
---------------------------------------------------------------------------

    \238\ Yanagisawa, M., Swanson, E., Azeredo, P., & Najm, W. G. 
(2017, April), Estimation of potential safety benefits for 
pedestrian crash avoidance/mitigation systems (Report No. DOT HS 812 
400), Washington, DC: National Highway Traffic Safety 
Administration.
---------------------------------------------------------------------------

    Regarding commenters' concerns surrounding redundancy between the 
proposed stationary mannequin conditions (i.e., S4a and S4b), in its 
model year 2021-2022 research tests, NHTSA found that, when comparing 
daylight results for each vehicle, the S4a test condition, where the 
stationary mannequin was facing away from the SV, resulted in more 
frequent vehicle-to-pedestrian contact across the incremented test 
trials compared to the S4b test condition, where the stationary 
mannequin was facing toward the SV. This same trend was observed for 
the Agency's darkness testing. Given these findings, NHTSA agrees with 
commenters that adding both S4a and S4b test conditions is not 
necessary to achieve improved PAEB performance. Thus, the Agency has 
chosen not to adopt the seemingly less stringent test condition for the 
stationary mannequin, S4b, for NCAP to reduce testing burden.
    While the Agency is removing one of the in-path stationary 
mannequin tests from NCAP's PAEB test matrix (i.e., S4b), it will not 
remove both stationary mannequin conditions, as some commenters 
requested. The Agency agrees with NACTO that stationary pedestrians 
should be accounted for when conducting PAEB testing; consumers expect 
PAEB systems to operate regardless of the pedestrian's movement, or 
lack thereof. Testing using a stationary pedestrian may also help to 
mitigate crashes in which a law enforcement officer or other first 
responder is standing in the roadway. Based on the results of the 
Agency's model year 2021-2022 research testing, in-path assessments for 
both stationary and moving pedestrian mannequins are necessary to 
ensure robust PAEB system performance. When comparing daylight results 
from the S4a tests to those for S4c, five vehicles contacted the 
mannequin at the uppermost test speed (60 kph (37.3 mph)) when the 
pedestrian was stationary (S4a), but not when it was moving (S4c). 
Furthermore, four vehicle models contacted the mannequin at the lowest 
test speed (10 kph (6.2 mph)) for the moving mannequin test (S4c) but 
not for either stationary test (S4a or S4b). Similar findings were 
observed during the Agency's darkness testing. Results for the S4a 
stationary mannequin condition with lower beam headlamps showed contact 
at 60 kph (37.3 mph) for three vehicles which was not similarly 
observed for the moving pedestrian condition. Furthermore, at 10 kph 
(6.2 mph), seven vehicles contacted the moving mannequin target during 
the S4c darkness tests but did not contact the stationary mannequin 
target at this same test speed in the S4a tests. In addition, five of 
these seven vehicles exhibited no reduction in speed. This is 
concerning because, as the Agency has mentioned previously, even low-
speed pedestrian crashes can be fatal. Further, as Subaru and others 
suggested, recent FARS data shows that the S4c test condition is 
representative of a common, fatal real-world crash. This is 
unsurprising since the pedestrian is facing away from the vehicle in 
these crashes and therefore may be unaware that a vehicle is 
approaching; if the driver of the vehicle is inattentive, it is even 
more likely that the vehicle may collide with the pedestrian. These 
results show that at very low and high speeds, PAEB systems may have 
trouble properly classifying moving and stationary pedestrians, 
respectively. Therefore, both stationary and moving targets should be 
assessed in NCAP's PAEB tests in daylight and dark lighting conditions 
and will proceed with adopting the S4a and S4c test scenarios 
accordingly.
    Although many vehicles exhibited contact at higher and/or lower 
speeds for the S4a and S4c test conditions, three vehicles offered 
complete crash avoidance for all test speeds, up to and including 60 
kph (37.3 mph) for both conditions during the Agency's daylight 
assessments, thus showing that robust performance is practicable. 
Further, although no vehicles were able to completely avoid contact 
with the pedestrian mannequin for all test speeds during darkness 
testing for the NCAP-adopted S4a and S4c scenarios, one vehicle only 
contacted the pedestrian mannequin at 10 kph (6.2 mph) for both 
conditions (i.e., S4a and S4c). In fact, of the 10 vehicles exhibiting 
contact at 10 kph (6.2 mph) in at least one of the two S4 test 
conditions in dark lighting being adopted, four avoided contacting the 
mannequin again completely during higher-speed tests in the scenario 
and three avoided contact until 60 kph (37.3 mph). These results 
demonstrate the achievability of future iterations of PAEB systems to 
fully avoid pedestrians for in-path stationary and moving pedestrian 
test conditions during assessments in both daylight and dark lighting 
conditions, making adoption of scenarios S4a and S4c in NCAP's

[[Page 95990]]

updated test matrix reasonable for both lighting variants.
False Positive Test Conditions (S1f and S1g)
    Regarding the false positive test conditions S1f and S1g, the 
Agency will not adopt these test conditions for NCAP's PAEB testing at 
this time. Despite the risk of drivers disabling PAEB if too many 
unnecessary activations occur, comments received regarding NCAP's 
inclusion of false positive testing negatively affecting system 
efficacy is also of concern, especially given the inherently vulnerable 
nature of those outside the vehicle. Data submitted by Toyota 
demonstrated that there is a potential overlap in the S1b and S1f cases 
up to 0.8 seconds TTC. As a result, systems may either falsely activate 
when it is not appropriate, or they may not activate when it is 
necessary to do so. Fewer false positive activations should not come at 
the expense of increased false negatives. Further, pedestrian behavior 
can be unpredictable, as Bosch noted. If there is a reasonable chance 
that the pedestrian will enter the vehicle's path, the vehicle's PAEB 
system should be prepared to react accordingly. The Agency reasons, as 
Intel suggested, that drivers will accept false activations in cases 
where the miss distance is small, especially at higher vehicle speeds, 
since the driver may not be certain that the individual will indeed 
avoid the vehicle's path. Additionally, NHTSA agrees that manufacturers 
have an interest in maintaining customer satisfaction. The lack of 
false positive testing does not prevent a manufacturer from optimizing 
its designs and improving sensor technology and system robustness. 
Nevertheless, the Agency plans to monitor real-world performance data 
to ensure that nuisance activations do not become problematic, 
especially given the numerous situations that may occur in the field. 
As mentioned for AEB, vehicles that have excessive false positive 
activations may pose an unreasonable risk to safety and, as such, may 
be considered to have a safety-related defect.
    The Agency acknowledges that its decision not to add false positive 
tests for PAEB is a departure from its treatment of false positive 
testing for AEB. NHTSA expects that a vehicle should encounter near-
miss pedestrians relatively less frequently than it encounters near-
miss situations with other vehicles. Therefore, a deficient PAEB system 
design should produce fewer unnecessary activations than a deficient 
AEB system. However, it is the Agency's intent to periodically revisit 
its review of the crash problem and adjust scenarios and test 
conditions accordingly, not only for false positive testing and PAEB 
assessments but for all ADAS testing.
Need for PAEB Assessments in Daylight and Dark Lighting Conditions
    Given the significant safety need described earlier in this notice, 
the proven feasibility of conducting PAEB testing in dark lighting 
conditions, and the ability for current systems to meet requirements, 
assessments in both daylight and dark lighting conditions are suitable 
for the adopted NCAP PAEB test conditions.
    For the adopted S1 crossing path test conditions (i.e., S1a, S1b, 
S1d, and S1e), one vehicle in the Agency's model year 2021-2022 
research testing was able to achieve full crash avoidance from 10 kph 
to 60 kph (6.2 mph to 37.3 mph) in all but one test condition, S1d, 
during testing in both daylight and dark lighting conditions using the 
vehicle's lower beam headlamps. For the S1d dark lighting test 
condition, the vehicle afforded full crash avoidance up to and 
including 30 kph (18.6 mph). Additionally, although eight of the 12 
vehicles contacted the pedestrian mannequin in each of the four 
crossing path conditions being adopted for NCAP's assessments in dark 
lighting conditions, three of these eight were able to achieve full 
avoidance in at least one crossing path test condition during daylight 
testing. These results show that excellent PAEB response in S1 dark 
lighting test conditions can be achieved, like those observed for 
testing in daylight, but for many vehicle models, there are further 
gains to be made specifically for PAEB performance under dark lighting 
conditions.
    For the adopted S4 in-path conditions and test speeds (i.e., S4a 
and S4c), five of the 12 models were able to fully avoid the mannequin 
target during daylight testing for at least one in-path condition; 
three of these five afforded full crash avoidance for both S4a and S4c 
test conditions. While none of the vehicles achieved full crash 
avoidance in either of the two adopted in-path test conditions during 
testing in the dark lighting condition using the vehicle's lower beam 
headlamps, many performed well between 20 kph and 50 kph (12.4 mph and 
31.1 mph) for both S4 test conditions. Furthermore, although eight out 
of 12 vehicle models failed to avoid the pedestrian mannequin in the 
S4c test condition at 10 kph (6.2 mph) in the dark lighting condition 
(with lower beam headlamps), only five of these same models failed this 
test condition variant during the corresponding tests in daylight. 
These results suggest that robust performance is achievable in both 
daylight and darkness assessments for the selected in-path test 
conditions; however, performance in one lighting condition does not 
necessarily translate to the other lighting condition.
    While the Agency acknowledges that its model year 2021-2022 PAEB 
testing demonstrated that current systems provided wide-ranging system 
capabilities during darkness testing for the adopted test conditions, 
it sees no reason to reduce the test matrix for testing in dark 
lighting condition, other than for the speed maximum speed to be 
assessed for the S1d condition, as will be discussed in the next 
section. NHTSA's research test results suggest that installation of 
improved sensing capabilities should allow for improved nighttime PAEB 
performance that more closely mirrors the performance observed during 
daylight. Further, the Agency reasons there is no reason to conduct 
only testing in darkness and forgo testing in daylight. As mentioned 
earlier, a significant number of pedestrian crashes occur in both 
lighting conditions. As such, the Agency must ensure system changes 
made to improve performance in darkness do not affect performance in 
daylight, and vice versa. In addition, because of the vast differences 
in current PAEB system capabilities, it is most reasonable to offer 
PAEB credit for performance in daylight separate from that of 
performance in darkness. By proceeding in this manner, the Agency 
expects it can more quickly award partial PAEB credit to current 
systems that may require relatively minor changes (i.e., to software) 
to perform successfully for all test variants in daylight.
2. Test Speeds
    Like its plan for AEB, NHTSA proposed to assess PAEB system 
performance over a range of test speeds for each of the test scenarios 
considered for inclusion. Specifically, NHTSA proposed to increase the 
SV test speed in 10 kph (6.2 mph) increments from a minimum test speed 
of 10 kph (6.2 mph) to a maximum test speed of 60 kph (37.3 mph) for 
each test condition, performing one trial per speed. To achieve a 
passing result for each speed, the Agency stipulated that the test 
trial must be valid (all test specifications and tolerances satisfied), 
and the SV must not contact the pedestrian mannequin. As will be 
discussed later, similar to its research testing of model year 2021 and 
2022 vehicles, the Agency further suggested that it would conduct up to

[[Page 95991]]

four additional trials for any specific test speed that resulted in a 
test failure (i.e., contact) as long as the SV had a relative velocity 
at impact equal to or less than 50 percent of the initial SV test 
speed. In such instances, NHTSA proposed that the SV must not contact 
the pedestrian mannequin for at least three out of the five total 
trials conducted to pass the test condition (i.e., combination of test 
scenario and test speed).
    The Agency believed it was appropriate to increase the maximum SV 
test speed from the 40 kph (24.9 mph) specified in its 2019 PAEB test 
procedure to 60 kph (37.3 mph) for all PAEB test conditions proposed 
for inclusion in NCAP for several reasons. First, as detailed in the 
real-world data section earlier, NHTSA reasoned that adopting a higher 
maximum PAEB test speed was necessary to drive improved PAEB system 
performance and address a larger portion of real world injuries and 
fatalities.\239\ Second, the Agency found that performing PAEB testing 
at 60 kph (37.3 mph) was reasonable, as NHTSA's model year 2019-2020 
(and subsequent model year 2021-2022) research testing showed that 
robust PAEB system performance across various test conditions was 
achievable at this higher test speed. Further, Euro NCAP prescribes a 
maximum vehicle speed of 60 kph (37.3 mph) in its PAEB testing for test 
conditions similar or identical to those proposed; in particular, S1a, 
S1c, S1d, S1e and S4c. Harmonizing test speeds with Euro NCAP should 
reduce manufacturer burden while also fulfilling mandates stipulated in 
the Bipartisan Infrastructure Law, which requires that the Agency take 
steps to harmonize with existing consumer information rating programs 
where possible and when appropriate.
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    \239\ The Agency hesitated to draw conclusions based solely on 
the travel speed data due to its significant limitations. The travel 
speed was either not reported or was unknown in 59 percent of fatal 
pedestrian crashes and 72 percent of pedestrian crashes that 
resulted in injuries. That being said, this data did show similar 
trends to that observed for posted speeds. For crashes that occurred 
on roadways where the travel speed was known, 14 percent of 
pedestrian fatalities and 70 percent of pedestrian injuries were 
reported for travel speeds of 40.2 kph (25 mph) and less, whereas 36 
percent of fatalities and 85 percent of injuries occurred for travel 
speeds of 60 kph (37.3 mph) and less. Like the posted speed data, 
the known travel speed data, although limited, also showed that 
adopting the higher maximum test speed of 60 kph (37.3 mph) would 
allow the Agency to capture additional fatalities and injuries, 21 
percent and 15 percent, respectively.
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    The Agency's reasons for proposing the minimum test speed of 10 kph 
(6.2 mph) for the planned PAEB test conditions were similar to those 
used to justify the proposed maximum test speed: harmonization and 
real-world relevance. Although the minimum test speed proposed is lower 
than the minimum speed prescribed in NHTSA's 2019 PAEB test procedure 
and in its characterization testing (i.e., 16 kph (9.9 mph)), the 
Agency noted that it aligns with the minimum test speed specified in 
Euro NCAP's pedestrian tests, except for Euro NCAP's Car-to-Pedestrian 
Longitudinal Adult (CPLA) scenario. The minimum vehicle test speed for 
the CPLA scenario, which is similar to the Agency's PAEB S4c test 
condition, is 20 kph (12.4 mph). NHTSA also believed that reducing the 
minimum test speed to 10 kph (6.2 mph) would ensure PAEB system 
functionality for very low speed crashes that may still cause injuries. 
Such injuries incurred from low-speed pedestrian collisions often 
result from secondary impacts with the ground.
    NHTSA also proposed to adopt Euro NCAP's approach to assessing 
vehicles' PAEB system performance by incrementally increasing the SV 
speed from the minimum test speed for a given scenario to the maximum. 
The Agency reasoned that such an approach would (1) harmonize with 
other consumer information programs on vehicle safety, (2) address 
comments received in response to NHTSA's December 2015 notice to expand 
the applicability of PAEB tests to include a broader range of test 
speeds, thus addressing a broader range of crash speeds driving 
pedestrian injuries and fatalities, and (3) ensure future PAEB systems 
effectively manage the inherent trade-off between a wider field-of-view 
needed for lower speed impacts and a narrower field-of-view necessary 
for distance detection in higher speed crashes. The Agency proposed 10 
kph (6.2 mph) increments for the test speed progression.
    The Agency sought comment on whether the proposed speeds and 
overall assessment approach were appropriate or whether alternatives 
should be considered.
Summary of Comments
    Many commenters agreed with the Agency's plan to set lower and 
upper bounds for SV test speed in PAEB testing to 10 kph (6.2 mph) and 
60 kph (37.3 mph), respectively. Toyota, Advocates, MEMA, NYC DOT/NYC 
DCAS Vision Zero Task Force, IDIADA, AAA, ASC, FCA, Rivian, Uhnder, 
BMW, Intel, HATCI, and ZF Group stated that this range of speed was 
appropriate. Some of those in favor mentioned that this speed range is 
representative of urban driving conditions to which pedestrians are 
typically exposed (roads with speed limits of 35 mph or less) (NYC DOT/
NYC DCAS Vision Zero Task Force, IDIADA, ASC, Uhnder, and Intel). 
Others (FCA and Rivian) noted that this speed range would lessen the 
testing burden for manufacturers because it aligns with Euro NCAP's 
PAEB speed range. Advocates, AAA, and Rivian cited the need to ensure 
that the technology works across a spectrum of vehicle speeds to 
address both lower- and higher-speed pre-impact scenarios, but 
Advocates added that NHTSA should continue to evaluate whether the 
proposed speed ranges will be adequate to protect all VRUs.
    Although Toyota agreed with the test speed range proposed by the 
Agency, it noted that physical intervention at higher speeds may 
interfere with a driver's ability to intentionally maneuver to avoid 
the collision since the vehicle must begin braking earlier. In 
addition, Toyota suggested that if there is a test speed (or subgroup 
of speeds) at which system performance is most representative of the 
entire speed spectrum, testing at that speed would be the most 
preferable solution as it would be the most efficient method to 
disseminate information to the public. Auto Innovators and GM also 
remarked that tests with SV speeds higher than 60 kph (37.3 mph) are 
more likely to damage test equipment. State Farm was generally 
supportive of higher vehicle speeds and conditions representative of 
real-world cases.
Minimum Test Speed Changes
    A few commenters disagreed with the lower boundary of NHTSA's 
proposed speed range. GM requested that the Agency begin testing PAEB 
S1 and S4 scenarios at 20 kph (12.4 mph). The automaker noted that the 
speed range of 20 kph (12.4 mph) to 60 kph (37.3 mph) is supported by 
other global consumer metrics and is referenced in a NHTSA-supported 
project.\240\ Auto Innovators and Honda requested that NHTSA allow 
vehicle manufacturers to select the minimum speed for PAEB testing, 
reasoning that modern AEB sensors are designed to prioritize 
functionality at higher, more injurious speeds. Since the speed 
differential between the SV and the pedestrian is lower at lower 
speeds, the pedestrian enters the AEB sensor field-of-view at a wider 
angle than at higher speeds. IDIADA also echoed this sentiment. Both 
groups noted that Euro NCAP and Japan New Car Assessment

[[Page 95992]]

Program (JNCAP) allows manufacturers to select the minimum speed.
---------------------------------------------------------------------------

    \240\ Carpenter, M.G., Moury, M.T., Skvarce, J.R., Struck, M. 
Zwicky, T.D., & Kiger, S.M. (2014, June), Objective tests for 
forward looking pedestrian crash avoidance/mitigation systems: Final 
report (Report No. DOT HS 812 040), Washington, DC: National Highway 
Traffic Safety Administration.
---------------------------------------------------------------------------

Maximum Test Speed Changes
    The upper speed range was also questioned by several commenters. 
Vision Zero Network, NTSB, CAS, League of American Bicyclists, and a 
number of individuals commented that they would like the Agency to run 
PAEB testing at speeds higher than 60 kph (37.3 mph). NTSB disagreed 
with NHTSA regarding its logic for selecting the upper test speed, 
stating that test specifications should not be based on current system 
capabilities but instead should drive systems toward ideal performance. 
CAS suggested that NHTSA determine the upper limits for each model's 
PAEB system to discourage designing to the test and to allow consumers 
to identify vehicles with superior performance. Vision Zero Network 
cited an IIHS study which found that PAEB is not efficient in areas 
with speed limits of 80.5 kph (50 mph) or greater. The League of 
American Bicyclists did not provide a preferred upper speed limit; 
however, the advocacy group did provide pedestrian fatality data to 
support upper speeds anywhere from 56.3 kph (35 mph) to 88.5 kph (55 
mph). Advocates, while supporting the speed range overall, also 
suggested that NHTSA evaluate whether the upper test speed limit is 
sufficient to capture the full range of real-world incidents. ZF Group 
supported increasing the test speed for test scenario S4c up to 80 kph 
(49.7 mph), as it could evaluate system capability in a pre-crash 
scenario involving a pedestrian walking along a rural road or highway 
with a higher speed limit. Comments from individuals were mostly in 
favor of increasing the speed range to anywhere from 64.3 kph (40 mph) 
to 120.7 kph (75 mph).
Incremental Speed Changes
    Regarding speed intervals between the minimum and the maximum, some 
(HATCI, ZF Group, and one individual) specifically offered support for 
10 kph (6.2 mph) speed intervals. ASC recommended that NHTSA use three 
test speeds to evaluate the range of performance more efficiently: 10 
kph (6.2 mph), 35 kph (21.7 mph), and 60 kph (37.3 mph). Adasky 
suggested that NHTSA drop to three test speed increments instead of six 
to allow resources to test a wider range of scenarios.
Response to Comments and Agency Decisions
    NHTSA will begin testing for each of the adopted PAEB test 
conditions at a minimum SV speed threshold of 10 kph (6.2 mph) and will 
increase the SV speed in 10 kph (6.2 mph) increments until a maximum 
speed threshold is reached, as long as the test vehicle does not make 
contact with the pedestrian mannequin during each progressive speed 
tested. For test conditions S1a, S1b, S1e, S4a, and S4c, the Agency is 
adopting a maximum SV speed threshold of 60 kph (37.3 mph) for both 
daylight and dark testing. For test condition S1d, the Agency is 
adopting a maximum SV speed threshold of 60 kph (37.3 mph) for daylight 
testing and 40 kph (24.9 mph) for dark testing. Travel speeds adopted 
for the pedestrian mannequins align with those proposed--5 kph (3.1 
mph) for the walking adult test conditions (S1a, S1b, and S4c) and the 
running child test condition (S1d), 8 kph (4.9 mph) for the running 
adult test condition (S1e), and 0 kph (0 mph) for the standing adult 
test condition (S4a). Should vehicle-to-mannequin contact occur at any 
speed, the test laboratory will discontinue the PAEB test series for 
the relevant lighting condition.
    Citing real-world relevance, testing feasibility, and reduced test 
burden due to harmonization, commenters generally favored the lower 
speed threshold (i.e., 10 kph (6.2 mph)) proposed by NHTSA. A few 
commenters, however, requested that NHTSA adopt an alternative minimum 
speed threshold, either one dictated by vehicle manufacturers' 
preference or 20 kph (12.4 mph) to align with other consumer testing 
programs. NHTSA reasons it is inappropriate to allow vehicle 
manufacturers to select the minimum speed for testing simply because 
some vehicles may currently prioritize functionality at higher, more 
injurious speeds, as Honda and Auto Innovators asserted. A vehicle 
striking a pedestrian at low speeds, such as 10 kph (6.2 mph), can 
still result in serious injuries or a fatality. Also, the minimum PAEB 
test speed of 10 kph (6.2 mph) is acceptable for NCAP's test matrix 
because it aligns with the lower-most test speed utilized by Euro NCAP 
for its CPNA, CPNCO, and CPFA tests, which are comparable to the 
Agency's S1a and S1c, S1d, and S1e tests, respectively.\241\ Adopting a 
minimum speed threshold of 10 kph (6.2 mph) allows the Agency to best 
achieve its goal to pursue harmonization, where reasonable, to reduce 
manufacturer burden and better fulfill the BIL's mandate that NHTSA 
consider the benefits of consistency with other U.S. and international 
rating systems.
---------------------------------------------------------------------------

    \241\ Euro NCAP prescribes a 20 kph (12.4 mph) lower speed 
threshold for its CPLA scenario, which is comparable to NHTSA's S4c 
test.
---------------------------------------------------------------------------

    The Agency is also selecting 10 kph (6.2 mph) as the minimum speed 
threshold because system performance at speeds below 10 kph (6.2 mph) 
does not appear to be practical at this time. The Agency's recent 
research testing for model year 2021 and 2022 vehicles showed that many 
vehicles were unable to prevent contact with the SV at 10 kph (6.2 
mph), even though these same models achieved acceptable performance at 
incrementally higher test speeds (i.e., 20, 30, 40 kph (12.4, 18.6, 
24.9 mph), etc.). This was observed for each of the various test 
conditions and lighting specifications.
    NHTSA is establishing a maximum speed threshold of 60 kph (37.3 
mph), as proposed, for nearly all of the test conditions adopted 
herein, with the exception of S1d testing conducted in darkness. A 60 
kph (37.3 mph) upper speed limit is generally appropriate for several 
reasons. Adopting this speed for the upper limit of the test speed 
range would permit safe test conduct and repeatability, as the 
pedestrian surrogates the Agency plans to use for testing allow impact 
speeds of 60 kph (37.3 mph). As mentioned above, a 60 kph (37.3 mph) SV 
speed is also consistent with that prescribed in Euro NCAP's AEB/LSS 
VRU systems test protocol for the comparable AEB test conditions (i.e., 
CPFA, CPNA, CPNCO, and CPLA).\242\ In addition, adopting a 60 kph (37.3 
mph) upper limit for the SV speed range allows the Agency to mitigate a 
large portion of the safety problem involving pedestrians. Recall that 
nearly 40 percent of all pedestrian fatalities and approximately three 
out of four pedestrian injuries occur in areas where the posted speed 
limit is 60 kph (37.3 mph) or lower.\243\
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    \242\ European New Car Assessment Programme (Euro NCAP) 
(December 2023), Test Protocol--AEB/LSS VRU systems, Version 4.5.
    \243\ See ``Linking Proposed PAEB Test Scenarios with Real-World 
Crashes'' section of this notice.
---------------------------------------------------------------------------

    A 60 kph (37.3 mph) maximum speed threshold has also proven 
practical for most of the PAEB test condition variants. The Agency's 
recent model year 2021-2022 research testing showed that while PAEB 
performance was generally inconsistent across the tested fleet, 
particularly for higher test speeds and dark conditions, at least one 
vehicle was able to completely avoid contacting the pedestrian 
mannequin at all test speeds from 10 kph (6.2 mph) up to and including 
50 kph (31.1 mph) and exhibited a speed reduction greater than 50 
percent at 60 kph (37.3 mph) for all but one of the adopted test 
condition

[[Page 95993]]

variants, S1d in darkness. For the S1d dark lighting variant, four 
vehicles were able to prevent contact with the test vehicle at all test 
speeds from the minimum test speed of 10 kph (6.2 mph) up to and 
including 30 kph (18.6 mph); however, when tested in darkness at 40 kph 
(24.9 mph), only two of these four vehicle models offered a speed 
reduction greater than 50 percent. As such, the next incremental test 
speed, 50 kph (31.1 mph), was not assessed to prevent damage to the 
test vehicle and equipment.
    Given these findings, a 60 kph (37.3 mph) upper speed limit is 
practical for current NCAP evaluation for all test condition variants 
except for the S1d darkness variant. By adopting 60 kph (37.3 mph) for 
the upper bound of the SV speed range, the Agency reasons it will 
mitigate as much of the safety problem as possible while not 
compromising test repeatability and safe test conduct. While NHTSA 
acknowledges that no one vehicle was able to provide complete crash 
avoidance for each of the test variants adopted herein, test vehicles' 
aggregate performance for available production PAEB systems is not 
indicative of shortcomings in the overall capability of PAEB 
technology. Instead, current systems are simply designed to meet a 
lower level of performance. It is noteworthy that IIHS's analogous 
testing for the S1d condition, the perpendicular child scenario, is 
currently conducted at 20 kph and 40 kph (12.4 mph and 24.9 mph), 
whereas the Agency is adopting test speeds for daylight testing ranging 
from 10 to 60 kph (6.2 to 37.3 mph) for this test condition.\244\ As 
such, the Agency reasons further improvements in PAEB system 
performance are possible as manufacturers optimize perception system 
hardware and software to meet the requirements stated in this notice. 
NHTSA observed a similar trend with the deployment of AEB technology 
approximately six years ago, when performance was inconsistent in NCAP 
for its AEB scenarios. AEB systems failed to meet all performance 
levels established for NCAP at that time, but AEB performance quickly 
improved as manufacturers updated and improved system software.
---------------------------------------------------------------------------

    \244\ Insurance Institute for Highway Safety (IIHS) (January 
2024), Pedestrian Autonomous Emergency Braking Test Protocol, 
Version IV.
---------------------------------------------------------------------------

    For the S1d darkness variant, it is appropriate to adopt an upper 
speed threshold of 40 kph (24.9 mph) at this time. While no vehicle was 
able to prevent contact with the pedestrian mannequin for this test 
variant during NHTSA's recent research testing at this test speed, two 
vehicle models provided a significant speed reduction (i.e., a speed 
reduction greater than 50 percent of the initial SV speed). 
Furthermore, the Agency recognizes, as mentioned earlier, that this 
test condition is performed by Euro NCAP at 60 kph (37.3 mph) at night, 
albeit with overhead lights in addition to the vehicle's lower beam 
headlamps. Therefore, it is practical, given minor software changes to 
improve system performance, for future iterations of existing systems 
to prevent contact with the pedestrian mannequin at a 40 kph (24.9 mph) 
test speed during S1d assessments in dark lighting conditions that 
utilize only vehicles' lower beam headlamps. As systems exhibit 
improved performance during testing, the Agency may then consider 
increasing the upper test speed for this test variant as part of future 
updates to the program.
    NHTSA acknowledges that there were a fair number of commenters who 
asserted that it should perform PAEB testing at speeds exceeding 60 kph 
(37.3 mph) (i.e., at speeds ranging from 80 kph (49.7 mph) to 120.7 kph 
(75 mph)). These commenters cited the ineffectiveness of current PAEB 
systems at higher speeds as well as pedestrian injury and fatality data 
that shows a safety need to curtail pedestrian-involved crashes at 
speeds exceeding the upper limit proposed by NHTSA. As mentioned, NTSB 
and CAS also encouraged NHTSA not to limit assessments to lower maximum 
speed thresholds dictated by current (NTSB) or average (CAS) system 
capabilities. Instead, these commenters suggested that NHTSA set upper 
test speed limits to drive system capabilities to meet ideal 
performance expectations or to identify superior performing systems.
    While there is merit to these suggestions and underlying rationale, 
NHTSA reasons that, given other decisions it is making to increase the 
stringency of its proposal, adopting a maximum speed of 60 kph (37.3 
mph) for the selected PAEB test scenarios is appropriate at this time. 
As detailed later, NHTSA has decided to implement a testing approach 
that requires (1) no contact with the pedestrian mannequin to prevent 
real-world injuries and (2) no repeated trials at a given test speed to 
ensure system robustness. Furthermore, a vehicle will not receive 
credit for passing NHTSA's PAEB test protocol unless it is able to meet 
these performance requirements for all test speeds across all test 
conditions for a given lighting condition. As evidenced in NHTSA's 
recent research testing, few PAEB systems were able to meet these 
requirements; therefore, it is expected that many may not receive PAEB 
credit for several years after the program changes take effect. Yet, it 
is important that NCAP provides consumers with useful information to 
guide their purchasing decisions. Steps taken to further increase the 
stringency of PAEB testing at this time will likely thwart this goal. 
Furthermore, the Agency should assess the implications of the 
anticipated changes on overall fleet performance to limit the effect of 
any unintended consequences before adopting more rigorous requirements. 
For instance, as Toyota noted, system intervention at high speeds may 
impede the driver's response to an impending collision. In addition, 
the Agency recognizes that, given PAEB system capabilities for the 
current vehicle fleet, increasing test stringency too quickly may spur 
an increase in false positives and thus consumer dissatisfaction. NHTSA 
expects that future system designs may include the use of long range 
lidar or other technology, which should improve overall system 
performance. As the state of technology advances, the Agency may 
consider raising the maximum test speed for one or more of the PAEB 
test condition variants (e.g., S4c in darkness) as part of future 
program enhancements upon conducting additional research to assess test 
feasibility, system advancements, and re-evaluation of the safety 
problem.
    The Agency also recognizes it is not feasible to proceed as Toyota 
suggested and select one test speed (or a subgroup of speeds, which 
other respondents also suggested) that would be most representative of 
system performance. While these alternative approaches may improve 
testing efficiency in one regard, since fewer runs would be required, 
they may also hinder it in another. If the Agency were to select one 
``representative'' speed for testing, it would choose the highest speed 
since it would generally be expected to be the most stringent and the 
one most likely to discern system performance for more injurious and 
fatal pedestrian crashes. However, evaluating system performance at 
only the highest test speed instead of at an incremental progression of 
speeds places both test equipment and the SV at greater risk for 
damage. Damage to test equipment or test vehicles not only introduces 
costly repairs but also delays testing. On the other hand, 
incrementally increasing speeds should often, though not always, reveal 
performance degeneration at more moderate speeds, thus limiting overall 
risk during testing and improving test efficiency. NHTSA also

[[Page 95994]]

reasons that conducting several additional runs for each test condition 
will have little impact on overall test efficiency or burden and seems 
inconsequential when considering the benefits ensuing from ensuring 
system robustness. An incremental testing approach should adequately 
ensure that PAEB systems which receive NCAP credit for passing 
requirements offer equivalent performance (i.e., no contact) across a 
range of speeds, as several commenters suggested. This is particularly 
important since pedestrians, who lack inherent protection from an 
impacting vehicle, may incur injuries and fatalities even at low 
vehicle speeds. However, NHTSA's latest research testing showed that 
not all PAEB systems that provide passing performance at higher speeds 
also perform well at lower speeds. As mentioned, some vehicles' systems 
failed to activate at speeds of 10 kph (6.2 mph) but prevented SV-to-
pedestrian mannequin contact at many higher test speeds, including the 
highest test speed assessed for a particular condition. The Agency also 
asserts that an incremental testing approach is appropriate for NCAP's 
PAEB assessments because it aligns with that adopted for the program's 
AEB tests and the testing methodology employed by Euro NCAP for its 
comparable VRU testing. Notwithstanding, NHTSA may also consider a 
reduction in the number of speed increments in the future, as Adasky 
suggested, if it looks to add test scenarios or conditions to the PAEB 
test matrix and fleet performance for PAEB systems has generally 
improved.
    As the Agency did not receive comments on the proposed walking and 
running speeds of the pedestrian mannequins stipulated for each test 
condition, it will adopt the speeds proposed. For the walking adult 
test conditions (S1a, S1b, and S4c) and the running child test 
condition (S1d), NHTSA is adopting a pedestrian mannequin speed of 5 
kph (3.1 mph). For the running adult test condition (S1e), the 
pedestrian mannequin speed will be 8 kph (4.9 mph), and for the 
standing adult test condition (S4a), the pedestrian mannequin will be 
stationary (i.e., 0 kph (0 mph)). These speeds are consistent with 
those used in NHTSA's PAEB characterization study, the 2019 draft NHTSA 
PAEB test procedures, and Euro NCAP's AEB/LSS VRU systems test protocol 
for the comparable test conditions.\245\ They were also determined to 
be appropriate for PAEB testing based on research conducted by 
Directorate-General for Research and Innovation and published in 
2014.\246\
---------------------------------------------------------------------------

    \245\ European New Car Assessment Programme (Euro NCAP) 
(December 2023), Test Protocol--AEB/LSS VRU systems, Version 4.5.
    \246\ https://cordis.europa.eu/docs/results/285/285106/final1-aspecss-publishable-final-report-2014-10-14-final.pdf at pg. 19.
---------------------------------------------------------------------------

3. PAEB Testing in Darkness--With Lower Beams and Use of Advanced 
Lighting Systems; With Upper Beams, in Lieu of or in Addition to Lower 
Beams, and With Overhead Lights; Other Technologies To Evaluate in Dark 
Lighting Conditions
    To evaluate PAEB performance in darkness, NHTSA planned to perform 
all proposed scenarios with the lower beam headlamps as the only source 
of illumination. However, if the vehicle is equipped with advanced 
lighting features, such as semiautomatic headlamp beam switching, 
adaptive driving beam (ADB), and/or high beam assist (HBA) headlighting 
systems, the Agency noted that these features would be engaged to 
function during the test as well. NHTSA requested comment on whether 
such a testing approach (i.e., a lower beam assessment that only allows 
automatic engagement of advanced lighting systems) was appropriate or 
whether it should additionally, or alternatively, consider testing in 
darkness that would allow manual activation of a vehicle's upper beams. 
In seeking comment on upper beam headlamp assessments, NHTSA noted that 
it is not guaranteed that upper beam headlamps will be used during 
real-world nighttime driving since the driver may need to manually 
activate them.
    NHTSA also asked whether it should utilize a secondary overhead 
lighting source, such as overhead streetlights, during PAEB testing. 
Overhead lighting is common in urban and suburban areas but scarcer 
along rural roads and highways. NHTSA notes that Euro NCAP's nighttime 
PAEB protocol specifies the use of overhead lighting for scenarios 
CPNA-25, CPNA-75, CPNCO-50, and CPFA-50 (which are similar to U.S. 
NCAP's S1a, S1c, S1d, and S1e, respectively) with the SV's lower beams 
activated. Euro NCAP's nighttime in-path scenario, the CPLA scenario 
(25 and 50 percent overlaps), which is similar to U.S. NCAP's S4c test, 
is performed with no overhead lighting and with the SV's upper beams 
engaged. As previously mentioned, NHTSA performed limited PAEB testing 
in darkness using lower beam headlamps and overhead streetlights, and 
the resulting data indicated only a slight improvement in PAEB system 
performance with overhead lighting compared to no overhead lighting.
    In devising its proposal, NHTSA reasoned that testing with the SV's 
lower beams engaged without overhead lights represents the presumed 
worst-case, real-world scenario, particularly at higher test speeds. 
Conditions such as these represented 36 percent of pedestrian 
fatalities, with 39 percent of fatalities in pedestrian crashes 
associated with low light conditions with overhead lights per FARS data 
from 2011-2015.\247\ The Agency reasoned that PAEB systems that meet 
the performance test specifications under dark lighting conditions with 
no overhead lights are likely to meet the performance specifications 
under dark lighting conditions with overhead lights, effectively 
addressing both conditions. NHTSA believed that assessing vehicles in 
the proposed manner (i.e., under dark conditions with no overhead 
lights and with the vehicle's lower beams) would encourage vehicle 
manufacturers to make design improvements to address a significant 
portion of crashes that currently result in pedestrian fatalities.
---------------------------------------------------------------------------

    \247\ Swanson, E., Foderaro, F., Yanagisawa, M., Najm, W. G., & 
Azeredo, P. (2019, August), Statistics of light-vehicle pre-crash 
scenarios based on 2011-2015 national crash data (Report No. DOT HS 
812 745), Washington, DC: National Highway Traffic Safety 
Administration.
---------------------------------------------------------------------------

    Beyond its current and proposed procedures, the Agency also sought 
further comment on (1) other technologies in development which may 
mitigate the significant nighttime pedestrian crash problem and (2) 
information available for evaluation under dark lighting conditions.
Summary of Comments
Use of High Beam, Low Beam, and/or ADB/Advanced Lighting Features
    Some respondents favored testing vehicles in dark lighting 
conditions utilizing lower beams only (i.e., with no advanced lighting 
system enabled), regardless of the scenario. Lidar Coalition, Velodyne, 
NYC DOT/NYC DCAS, Aptiv, and one individual suggested that the 
theoretical worst-case scenario would be the one with the least 
illumination. Lidar Coalition stated that this test procedure 
specification was ``critical'' because each technology used for 
detecting pedestrians has its own advantages and limitations. The group 
said that these procedures would drive the need for updated sensor 
types that achieve good performance across all driving conditions, 
particularly ones in which the human eye fails to identify a 
pedestrian. Velodyne provided data to support the Agency's accounting 
for scenarios where current systems

[[Page 95995]]

underperform; the Governor's Highway Safety Association (GHSA) found 
that 75 percent of pedestrian fatalities occur at night. NYC DOT/NYC 
DCAS noted that in NHTSA's testing, vehicles were repeatedly able to 
avoid crashing into the pedestrian mannequin while utilizing only the 
vehicle's lower beams, indicating that it is possible to achieve this 
level of performance. Aptiv suggested that vehicles should not be 
tested with any advanced lighting features enabled because they can be 
disabled by the consumer. In light of this, the commenter deduced that 
vehicles would be evaluated on a level playing field if no advanced 
lighting systems are enabled. One commenter, Vayyar, suggested that 
NHTSA run a test with no headlamp illumination at all, stating this 
will allow NHTSA to evaluate how well PAEB sensors work in total 
darkness.
    There were also commenters, however, that recommended testing 
vehicles using the vehicle's lower beams along with advanced lighting 
systems in certain instances. Some reasoned that advanced lighting 
systems should only be used when they are enabled by default or enabled 
at key-on. CAS, Advocates, Tesla, AAA, Uhnder, Adasky, and IDIADA 
suggested this approach as a possibility. HATCI mentioned that vehicles 
should be tested in their default configurations during ADAS testing 
and that advanced lighting systems should be enabled during PAEB 
testing under dark lighting conditions. However, the automaker did not 
specifically state that advanced lighting systems must be on by default 
to be included in the test protocol. CAS, Uhnder, and Adasky stated 
that advanced lighting systems should be enabled only if they cannot be 
disabled by the user. They reasoned that it is important to evaluate 
the worst-case scenario, which in their opinion is use of lower beams 
with the adaptive driving beam/advanced lighting features disabled, 
where possible. Uhnder added that drivers often turn off advanced 
features when they can and that drivers often do not utilize upper 
beams appropriately while driving. ZF Group also shared this assertion.
    Many commenters stated that advanced lighting systems should always 
be enabled, regardless of whether they are standard or automatically 
enabled by default. Advocates, Intel, FCA, BMW, Honda, Toyota, ASC, 
Rivian, Bosch, Subaru, Auto Innovators, The League, Vayyar, ZF Group, 
GM, and several individuals supported the use of advanced lighting 
systems during PAEB testing in dark conditions. BMW suggested that 
separate tests should be conducted with lower beams and with the 
advanced lighting systems enabled, adding that NHTSA should weight one 
over the other. Alternatively, BMW stated that only testing with 
advanced lighting systems for those vehicles equipped could lower the 
testing burden. Honda noted that advanced lighting systems are meant to 
work with PAEB systems at night and should be enabled to capture the 
system's intended performance. Rivian echoed Honda's sentiment. Subaru 
and Auto Innovators pointed out that ADB is not required to function 
below 32.2 kph (20 mph), so tests should begin at this speed.
    Advocates, Tesla, Toyota, Bosch, Subaru, Auto Innovators, The 
League, and GM stated that manufacturers may be encouraged to include 
advanced lighting systems in their vehicles if they are able to be used 
during PAEB testing in dark lighting conditions. Subaru suggested that 
NHTSA offer extra credit for vehicles equipped with advanced lighting 
capabilities. IIHS and one individual requested that NHTSA focus on 
adding an advanced lighting requirement to all new vehicles, citing 
safety benefits.
    For vehicles not equipped with ADB, HBA, or other advanced lighting 
technologies, Honda, Rivian, Subaru, FCA, and The League expressed that 
NHTSA should assess at least some scenarios with the SV's high beams 
manually activated. Rivian specified that high beams should only be 
engaged in dark driving conditions as it is unlikely that an SV would 
be traveling in an area without ambient lighting or oncoming vehicles 
with lower beam headlamps only. The League and Subaru agreed with this 
reasoning. Subaru also mentioned that high beam usage more closely 
compares to HBA or ADB activation. FCA suggested that a vehicle's upper 
beams should be used in scenario S4 testing to lessen test burden. A 
few respondents noted that tests should be run both with lower and 
upper beams, with IIHS, CAS, and a few individuals favoring this 
strategy. However, CAS clarified that only the worst-case, lowest-
illumination results should factor into capability ratings. IIHS stated 
it plans to give higher weight to high beam results in vehicles with 
HBA capability for tests in which the speed is over the threshold for 
activating HBA. Intel stated that vehicles should achieve partial 
credit if they pass with manual high beam engagement, thus motivating 
manufacturers to include advanced lighting features in their vehicles. 
ASC did not support the use of any manually-activated high beams, and 
AAA requested additional data to show that drivers use high beam 
lighting frequently before allowing manual high beam activation.
    NHTSA also received comments regarding headlighting features, 
specifically advanced headlighting systems. GM sated that there is an 
opportunity for the Agency to list advanced lighting features on 
NHTSA's website as a method of promoting the technology, therefore 
driving adoption into the vehicle fleet. The automaker reasoned that 
there are safety benefits associated with ``Auto High Beam,'' noting 
that the benefits found are at least as great as those for LDW, another 
feature that NHTSA has listed for new vehicles on its website. GM also 
noted that far-infrared cameras do not have associated field 
effectiveness data at this time due to low penetration rate but 
suggested that they still be added to a listing of safety features. 
Honda, Auto Innovators, BMW, FSS, TI, and Intel agreed that adoption of 
advanced lighting features such as Auto High Beam should be 
incentivized. FSS noted that advanced lighting features not only 
improve PAEB performance but also eliminate glare from oncoming 
vehicles, improving visibility for other drivers in the surrounding 
area. FSS also referred to IIHS's vehicle lighting ratings and the 
positive effect on nighttime crash rates for vehicles earning the 
group's ``good'' rating versus a ``poor'' rating. To encourage 
installation of advanced lighting features in the U.S. vehicle fleet, 
BMW and Auto Innovators suggested NHTSA provide additional credits for 
vehicles equipped with an advanced lighting feature. Texas Instruments 
(TI) recommended that advanced lighting features be added to NCAP 
ratings in some capacity but did not specify how this should be 
accomplished. MEMA, CR, HMNA, and NTSB were among other respondents in 
favor of incorporating lighting for improved nighttime pedestrian 
visibility.
Overhead Lighting
    NHTSA also requested comments on overhead lighting for PAEB testing 
under dark lighting conditions. NHTSA notes that rural environments 
tend to be darker and without ambient overhead lighting, while urban 
and suburban environments are typically more well-lit from overhead 
lights, surrounding vehicle headlamp illumination, and other various 
light sources. Some commenters reasoned that the lighting should match 
the environment of the scenario approximated. MEMA, BMW, HATCI, Subaru, 
and Auto Innovators were in favor of having overhead

[[Page 95996]]

lighting for urban and suburban scenarios but no overhead lighting for 
scenarios which more closely reflect rural encounters. Subaru specified 
that urban/suburban scenarios should have overhead lighting of 15 lux 
to simulate street lighting and that lower beams should be acceptable 
in these scenarios. In scenarios with no supplemental lighting, ADB or 
HBA would be expected to engage if the vehicle was equipped with 
advanced lighting features. If the SV does not have advanced lighting 
features, then some commenters (MEMA, BMW, HATCI, Auto Innovators, and 
Intel) asserted that high beams should be engaged. BMW also suggested 
that high beams should be engaged in higher-speed testing scenarios 
(tests with initial test speed at 50 kph (31.1 mph) or greater). HATCI 
mentioned that high beams should be allowed in dark conditions with no 
overhead lighting if high beam usage is shown to be common in the field 
in these situations.
    GM suggested that scenarios be performed in two conditions: with 
overhead lighting and the use of low beams, and without overhead 
lighting and upper beam headlamps or advanced lighting features. The 
automaker reasoned that these two conditions represent a large portion 
of real-world driving conditions. Bosch, ZF Group, AARP, Intel, State 
Farm, The League, and one anonymous individual agreed that testing 
should be performed both with overhead lighting as well as in dark 
lighting conditions. The League also noted that if overhead lighting is 
shown to improve PAEB performance, then street lighting should be more 
widely deployed with the assistance of Congress, the U.S. Department of 
Transportation (USDOT), and the Federal Highway Administration (FHWA).
    Many commenters expressed particular interest in the opportunity to 
harmonize with other global consumer information programs, with many 
responding to the proposed PAEB protocol noting that overhead lighting 
is used in Euro NCAP's protocol for crossing path tests in low ambient 
light conditions.\248\ Bosch, TI, MEMA, GM, HATCI, Auto Innovators, and 
NSC were in favor of harmonizing NHTSA's NCAP PAEB test procedures 
under dark lighting conditions with Euro NCAP's. Tesla supported 
harmonization with IIHS's then-upcoming PAEB protocol, which does not 
involve the use of overhead lighting. IIHS plans to test using both 
lower beam and upper beam headlamps.
---------------------------------------------------------------------------

    \248\ European New Car Assessment Programme (Euro NCAP) 
(December 2023), Test Protocol--AEB/LSS VRU systems, Version 4.5. 
See Annex B.
---------------------------------------------------------------------------

    One commenter, FCA, only supported conducting tests with overhead 
lighting as part of this upgrade. The group stated that current PAEB 
camera technology requires illumination to the sides of the vehicle and 
that regulatory restrictions prevent headlighting systems from 
achieving this level of illumination on their own. It also noted that 
this condition is more severe than Euro NCAP's current protocol. The 
group suggested that the Agency could add tests without overhead 
lighting at a future time when technology advances.
    There were also many respondents (Lidar Coalition, Velodyne, NACTO, 
Advocates, CAS, Adasky, AAA, IIHS, ASC, and three individuals) who 
commented that no overhead lighting should be used in PAEB testing. As 
mentioned previously, Lidar Coalition supported testing in the darkest 
realistic conditions possible, comments also supplied by Velodyne, CAS, 
and an anonymous individual. Further, both Velodyne and Lidar Coalition 
stated that testing without supplemental lighting would highlight the 
need for new sensors and technologies that will ``achieve optimal 
detection'' of VRUs in all road conditions. NACTO urged NHTSA to 
consider the known shortcomings of PAEB systems when deciding which 
scenarios and test conditions to include in its NCAP test procedures, 
citing an IIHS study showing that PAEB systems are less effective in 
dark conditions.\249\ One individual noted that pedestrians are often 
fatally struck by vehicles while walking in areas without streetlights 
and suggested that the Agency evaluate performance in commonly 
encountered dangerous situations to achieve NCAP's safety goals. 
Advocates stated it was in favor of testing without overhead lighting 
because of the wide array of street light types and brightness in the 
U.S., and the increased stringency that testing in dark conditions 
would present. Because of the abundance of rural and highway roads 
without overhead street lighting, Adasky stated that testing should be 
conducted in zero lux conditions. AAA expressed that testing with 
overhead lighting does not challenge a PAEB system as much as the use 
of advanced lighting or low beam headlamp use does in isolation and 
therefore suggested that the Agency conduct tests without supplemental 
lighting, also noting that many pedestrians are struck in areas without 
overhead lighting.
---------------------------------------------------------------------------

    \249\ Cicchino, J. B (2022, February), Effects of automatic 
emergency braking systems on pedestrian crash risk, Insurance 
Institute for Highway Safety, https://www.iihs.org/api/datastoredocument/bibliography/2243.
---------------------------------------------------------------------------

Additional Information Supplied
    Regarding available technology and other information, several 
commenters suggested that NHTSA should evaluate each technology type 
currently available and, in some cases, investigate the effectiveness 
of each. ASC noted that high resolution imaging radar, lidar, and 
thermal imaging cameras are available to address nighttime scenarios. 
NSC requested that NHTSA compare camera-based systems with lidar and 
other technologies in both light and dark conditions. Rivian 
acknowledged that there are limitations on FCW and PAEB technology's 
performance currently, specifically noting performance during dark 
lighting conditions. The automaker advocated for consideration of 
current system capabilities when determining NCAP test speeds and 
scenarios.
    Other commenters offered information regarding specific sensor 
types. Tesla noted that infrared cameras may aid in pedestrian and 
animal detection in nighttime conditions. Vayyar mentioned that these 
enhanced attributes help the system provide robust monitoring. Thermal 
cameras were also specifically recommended by Adasky and one 
individual, with both respondents touting thermal cameras' abilities to 
perform in varied lighting situations, including nighttime, rain, snow, 
and fog. Both commenters claimed that this is because thermal cameras 
do not depend on ambient light to operate effectively. The individual 
commenter expressed that they were therefore in favor of more 
challenging test conditions since technology exists to address them. 
Adasky also added that thermal cameras have a wide field-of-view and 
longer range, and since even high beam lighting can only currently 
illuminate 120 m (393.7 ft.) to 150 m (492.1 ft.) ahead of the vehicle, 
high rates of speed require the system to be able to identify objects 
200 m (656.2 ft.) ahead to reduce false positives. Lidar Coalition and 
Velodyne Lidar disagreed, opining that thermal cameras have limitations 
of their own: low resolution, placement restrictions, and potential to 
miss objects due to blending of separate objects' head characteristics. 
Instead, both groups stated that lidar systems are more capable of 
addressing nighttime scenarios because they rely on their own light 
source and have a higher resolution than radar. In addition to thermal 
cameras and lidar, Uhnder responded that imaging radar is also of 
higher resolution than most radar systems used in PAEB applications 
currently and is a promising technology.

[[Page 95997]]

TI and Vayyar suggested that four-dimensional (4D) radar systems may 
increase system effectiveness. With regard to 4D systems, TI stated 
that ``cascading multiple radar sensors provides a wider field of view, 
an extended range, and enhanced angle resolution to detect static 
objects.''
    ITS suggested that night view assist, a system using infrared 
headlamps, is already available in certain vehicle models. The vehicle 
displays a view of upcoming obstacles in the instrument cluster to give 
the driver advanced notice. ITS favored including the technology in 
safety ratings but also reasoned that including this technology in 
NHTSA's ``recommended technologies'' section would be appropriate.
Response to Comments and Agency Decisions
    Details regarding lighting specifics for each condition to be 
tested are included in the sections that follow.
Vehicle Lighting Specifications, Including Advanced Lighting Systems
    NHTSA proposed to use the SV's lower beam headlamps during all NCAP 
PAEB testing conducted in the dark and to refrain from manually 
engaging the upper beam headlamps. After considering comments, this 
notice adopts this plan. NHTSA will also prohibit automatic engagement 
of a vehicle's upper beams by way of advanced lighting systems, such as 
ADB, unless such systems cannot be deactivated.
    NHTSA acknowledges that, as mentioned in the March 2022 RFC notice 
and above, Euro NCAP performs its CPLA scenario, which is analogous to 
the Agency's S4c scenario, using upper beam headlamps. FCA supported 
this test specification to lessen test burden on manufacturers. 
Additionally, BMW requested that NHTSA manually engage upper beam 
headlamps during higher-speed (50 and 60 kph, or 31.1 and 37.3 mph) 
PAEB testing conducted in the dark. However, previous studies have 
suggested that drivers may not manually engage high beam headlamps each 
time they are warranted,\250\ and NHTSA is not aware of definitive data 
available at this time to suggest that drivers use them appropriately 
in the field, as Rivian and other commenters had suggested. IIHS found 
that, for 3,200 isolated vehicles (where other vehicles were at least 
10 or more seconds away), only 18 percent had their upper beam 
headlamps engaged.\251\ At one unlit urban location, IIHS data showed 
that upper beam use was less than 1 percent. IIHS also found that even 
on rural roads, drivers used their upper beams less than half of the 
time they should have for maximum safety, on average. Accordingly, it 
is inappropriate to tie PAEB to a vehicle feature that a driver may or 
may not use on a trip. NHTSA agrees with several respondents that 
supporting data would be necessary to allow manual high beam headlamp 
usage.
---------------------------------------------------------------------------

    \250\ Sullivan, John M., Adachi, G., Mefford, Mary Lynn, 
Flannagan, Michael J. (2003, February). High-Beam Headlamp Usage on 
Unlighted Rural Roadways. The University of Michigan Transportation 
Research Institute. https://deepblue.lib.umich.edu/bitstream/handle/2027.42/55182/UMTRI-2003-2.pdf.
    \251\ https://www.iihs.org/news/detail/few-drivers-use-their-high-beams-study-finds (last accessed 11/18/2023).
---------------------------------------------------------------------------

    Similarly, the Agency has also decided that advanced lighting 
systems, including ADB, will be disabled during NCAP PAEB testing 
conducted in the dark, unless the advanced lighting system cannot be 
deactivated. This decision will apply even to those systems that are 
active by default when low beam headlamps are first engaged. 
Furthermore, for lighting systems with adjustable settings, the vehicle 
will be tested in dark conditions utilizing the beam/lighting 
configuration that is most similar to a traditional low beam setting, 
unless the beam/lighting configuration is automatically adjusted.
    While NHTSA amended its lighting standard, FMVSS No. 108, ``Lamps, 
reflective devices, and associated equipment,'' in 2022 to allow 
installation of ADB headlamps, citing the potential to provide safety 
benefits in preventing collisions with pedestrians when other vehicles 
are present,\252\ such systems are not required by this Standard, 
unlike lower beam and upper beam headlamps. Therefore, NHTSA reasons, 
as several commenters mentioned, that even if an ADB system or other 
advanced lighting system were installed on a vehicle, the driver may 
opt not to use it. Accordingly, it is most desirable from a safety 
standpoint for NCAP to assess those conditions that represent, as Aptiv 
suggested, a theoretical worst-case scenario--testing in dark 
conditions with only the vehicle's lower beam engaged. Several 
commenters expressed concern that vehicles will not be evaluated 
equally if advanced lighting features are enabled, stating that they 
are akin to upper beam headlamps. In the same vein, others suggested 
that NHTSA evaluate PAEB performance with upper beam headlamps if 
advanced lighting systems are enabled for use in the lower beam tests. 
The Agency recognizes that ADB works by automatically switching from 
the lower beam to the upper beam when it is deemed appropriate. As 
such, testing PAEB in the dark with ADB (or other advanced lighting 
systems) enabled may amount to NHTSA only evaluating system performance 
when the vehicle's upper beam is active. Finally, because ADB and other 
advanced lighting systems will not be enabled for NCAP's PAEB testing, 
commenters' concerns regarding ADB activation speeds are no longer 
applicable.
---------------------------------------------------------------------------

    \252\ 87 FR 9916.
---------------------------------------------------------------------------

    Although NHTSA received suggestions to conduct testing using upper 
beam headlamps in addition to testing using lower beam headlamps, the 
Agency does not see the need to increase NCAP test burden at this time. 
A vehicle which performs well in the lower-illumination case would be 
expected to also perform well when there is more illumination. Notably, 
more vehicle-to-target contact was observed during the lower beam PAEB 
research tests than the upper beam tests. However, NHTSA also 
recognizes that, in rare cases, vehicles may perform better in PAEB 
testing with the lower beams illuminated versus the upper beams. The 
Agency plans to monitor PAEB performance under various circumstances 
and will address any further needs for additional testing as they 
become apparent.
    While the Agency acknowledges Vayyar's suggestion that NHTSA 
conduct testing with no headlighting system illumination under the 
assumption that this would best test the sensing system and provide a 
true worst-case evaluation, this is not a reasonable use case. In areas 
synonymous with NHTSA's lighting test conditions (i.e., darkness with 
no overhead lighting), failure to turn on one's headlamps should yield 
such limited visibility that the Agency reasons drivers will almost 
certainly realize they are not utilizing their lights and turn them on. 
Driving in dark conditions without headlamps also constitutes a 
significant and dangerous misuse situation. While NHTSA agrees there is 
merit to assessing worst-case conditions in many circumstances, the 
Agency also sees benefit in ensuring that test cases are also field-
representative use cases.
    Several commenters suggested that NHTSA promote the installation of 
advanced lighting systems not only to mitigate nighttime pedestrian 
crashes but to improve nighttime visibility in general by eliminating 
glare. GM submitted data to show an estimated 22 percent field benefit 
from Auto High

[[Page 95998]]

Beam systems, mitigating nighttime pedestrian, cyclist, and animal 
crashes.\253\ However, as there will be no method for assigning extra 
credit for vehicles with added safety features at this time, NHTSA will 
not implement multiple commenters' suggestions to offer additional 
points or credit to vehicles equipped with advanced lighting systems, 
nor will the Agency allow vehicles to receive partial credit for 
passing with manual upper beam usage as suggested by Intel. More 
research is needed to ascertain safety benefits associated with night 
view systems. While it is out of scope for NHTSA to require advanced 
lighting features on new vehicle models as part of this final notice as 
some commenters requested, the Agency has added advanced headlighting 
assessments to its long-term NCAP roadmap.
---------------------------------------------------------------------------

    \253\ https://www.regulations.gov/comment/NHTSA-2021-0002-3856.
---------------------------------------------------------------------------

Overhead Lighting
    NHTSA agrees that unlit roads are treacherous for pedestrians. As 
both AAA and an individual commenter noted, pedestrians are often 
fatally struck while walking in areas without supplemental lighting. 
For example, IIHS found that in 2019, 35 percent of pedestrian 
fatalities occurred in the dark with no supplemental lighting 
present,\254\ which is nearly the same as that found by Volpe in its 
2011-2015 data set (36 percent).\255\ Further, a study of California, 
North Carolina, and Texas crashes from 2010-2019 found that pedestrians 
struck in areas without street lights were 2.4 times more likely to be 
fatally injured than those struck in areas with street lights.\256\
---------------------------------------------------------------------------

    \254\ Cicchino, J.B. (2022, February), Effects of automatic 
emergency braking systems on pedestrian crash risk, Insurance 
Institute for Highway Safety, https://www.iihs.org/api/datastoredocument/bibliography/2243.
    \255\ Swanson, E., Foderaro, F., Yanagisawa, M., Najm, W.G., & 
Azeredo, P. (2019, August), Statistics of light-vehicle pre-crash 
scenarios based on 2011-2015 national crash data (Report No. DOT HS 
812 745), Washington, DC: National Highway Traffic Safety 
Administration.
    \256\ Ferenchak, N.N., Gutierrez, R.E., & Singleton, P.A. 
(2022), Shedding light on the pedestrian safety crisis: An analysis 
across the injury severity spectrum by lighting condition, Traffic 
Injury Prevention, 23:7, 434-439, DOI: 10.1080/
15389588.2022.2100362.
---------------------------------------------------------------------------

    Based on this, the Agency has decided it will conduct all testing 
under dark lighting conditions with no overhead lighting present. As 
previously mentioned, the Agency's testing showed only slightly 
improved performance when conducting PAEB tests with overhead lighting 
present versus no overhead lighting. Given these findings, the Agency 
asserts it is also least burdensome to conduct testing in the darkest 
environmental scenario only.
    NHTSA acknowledges that some commenters suggested it match the 
environmental lighting conditions for each test to the analogous real-
world scenario, with overhead lighting used for S1 crossing path 
scenarios, while no overhead lighting would be used for S4 in-path 
scenarios. Commenters noted that Euro NCAP performs its PAEB tests in 
this manner. However, the Agency concludes there are several reasons 
its planned testing approach is the most appropriate at this time.
    First, environmental lighting conditions vary across the U.S. Light 
color (i.e., color temperature), uniformity, luminance level, and other 
parameters may differ, even along different stretches of the same 
roadway. As Advocates noted, there are also a wide variety of 
streetlight types in use on U.S. roadways, making it difficult for the 
Agency to choose one streetlight specification that is representative 
of all or most overhead lighting conditions. Instead, it is most 
practical to conduct PAEB testing in dark conditions which can be more 
easily replicated. Such testing would align with Adasky's assertion 
that many American roads are not lit.
    In addition, the Agency reasons that conducting NCAP's PAEB tests 
under dark lighting conditions may not only mitigate pedestrian 
involvement in crashes at night, but also encourage the development of 
more robust sensing and detection technologies. Specifically, although 
there are natural limits to the human eye's vision capabilities in dark 
conditions, several commenters described various technologies that 
substantially augment a driver's ability to detect objects and 
pedestrians. The commenters noted the benefits of these technologies in 
different conditions, including darkness, rain, snow, and fog. While 
the Agency agrees there are technologies available to fulfill this 
need, it is inappropriate to promote or mandate one sensor technology 
over another, particularly since there are advantages and limitations 
to each, as Lidar Coalition stated. Instead, NHTSA intends to test the 
capabilities of the system as a whole. This should allow vehicle 
manufacturers the ability to address each nighttime scenario as they 
wish and may in turn spur innovation.
    In response to FCA's suggestion that overhead lighting is necessary 
based on the concern that regulatory barriers may prevent manufacturers 
from designing headlamps providing sufficient illumination to the sides 
of the vehicle so as to perform well in PAEB testing under dark 
lighting conditions, the Agency found this not to be the case during 
its research testing series. As described earlier, some vehicles were 
able to perform well in most of the adopted PAEB tests conducted under 
dark lighting conditions, proving that regulations do not restrict 
system designs which are effective. Based on this, the knowledge that 
PAEB is generally less effective when driving in dark conditions, and 
the substantial percentage of pedestrian fatalities that occur in 
conjunction with a lack of street lighting overhead, NHTSA concludes it 
is most appropriate at this time to move forward with testing without 
the use of supplemental lighting.
    Finally, NHTSA notes that although Euro NCAP uses overhead lighting 
for its CPNA, CPNCO, and CPFA testing, IIHS does not utilize 
supplemental lighting for any of its nighttime PAEB testing. Instead, 
IIHS requires that test site illumination must be below 1 lux.\257\
---------------------------------------------------------------------------

    \257\ Insurance Institute for Highway Safety (IIHS) (January 
2024), Pedestrian Autonomous Emergency Braking Test Protocol, 
Version IV.
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4. Number of Required Trials To Pass and Repeat Trials in the Event of 
Contact
    In its March 2022 notice, the Agency proposed an evaluation method 
for PAEB similar to that proposed for AEB. NHTSA presented a plan to 
perform one trial per test speed, beginning at a 10 kph (6.2 mph) 
minimum SV speed. If the SV did not contact the pedestrian mannequin 
during this initial trial, the test speed would be raised incrementally 
by 10 kph (6.2 mph) until a maximum test speed of 60 kph (37.3 mph) was 
achieved and evaluated. If the SV contacted the pedestrian mannequin 
during an initial trial for a given test condition and test speed 
combination, the resulting next steps would depend on the relative 
longitudinal velocity of the SV at impact. If the SV's relative 
longitudinal velocity at impact was less than or equal to 50 percent of 
the SV's initial test speed, then up to four more confirmatory tests at 
the same SV speed would be performed. The SV could not contact the 
pedestrian mannequin in three or more of the five total tests. However, 
if the SV contacted the pedestrian mannequin at a relative longitudinal 
velocity greater than 50 percent of the SV's initial speed, testing 
would be discontinued. This is because the vehicle would be considered 
to have failed the PAEB test evaluation at this test speed and, 
consequently, the PAEB test overall. Noting that 50 percent of the 
minimum test speed (10 kph, or 6.2

[[Page 95999]]

mph) is 5 kph (3.1 mph) and 50 percent of the maximum speed possible 
(60 kph, or 37.3 mph) is 30 kph (18.6 mph), NHTSA requested comments on 
whether a 50 percent limit on the maximum relative impact velocity was 
an appropriate threshold to establish at which additional testing 
(i.e., repeat trials) would be conducted for the proposed range of test 
speeds.
    Given the large number of PAEB test conditions proposed for 
adoption (i.e., eight conditions covering multiple test speeds and 
lighting specifications), NHTSA noted that its proposed approach to 
reduce the number of test trials required at a given test speed from 
those specified in the original draft 2019 PAEB test procedure was a 
reasonable attempt to reduce test burden. The Agency believed that 
assessing PAEB system performance over subsequent incremental trials 
and for multiple repeated trials in instances where a vehicle is unable 
to meet the ``no contact'' performance requirement in the initial valid 
trial for a particular combination of test condition and speed would 
best integrate program efficiency while still ensuring system 
robustness.
    In addition to seeking comments on its proposed assessment 
approach, NHTSA also sought comment on whether it should instead pursue 
an alternative approach, such as conducting multiple trials for each 
test condition and speed combination regardless of whether the ``no 
contact'' performance criterion was met. The Agency collected a wide 
variety of comments in response to these questions.
Summary of Comments
    A few commenters, including AAA and ASC, agreed with NHTSA's 
proposed testing approach in its totality. Another commenter, Adasky, 
relayed that NHTSA's plan was sufficient if information about any 
potential test failures is made clear to the public. However, several 
commenters suggested NHTSA adopt an entirely different testing 
approach. Specifically, MEMA, HATCI, Auto Innovators, and Intel 
recommended the Agency employ the evaluation method currently utilized 
by Euro NCAP, whereby the Agency would accept self-reported performance 
predictions from manufacturers and then randomly select scenarios and 
test speeds to verify vehicle performance. Intel further commented that 
if the results of a spot-check test match the manufacturer's results, 
then the test would be accepted (and points could be awarded based on 
performance), but if the results differed between the manufacturer's 
data and NHTSA's, then two additional tests would be performed. If two 
of the three trials did not produce the manufacturer's predicted 
results, the company suggested partial credit could be given, and a 
correction factor could be applied. The commenters noted this method of 
evaluation would achieve the desired result of reducing the test burden 
on NHTSA labs.
    One commenter, CAS, stated the performance criteria proposed by the 
Agency could be more stringent. The organization explained that systems 
offering no contact performance for five of five tests ``provide only 
86% reliability with 50% confidence.'' Accordingly, CAS opined 
additional tests should only be allowed after pedestrian mannequin 
contact if the manufacturer changed the vehicle's configuration in 
response to the impact. Under CAS's plan, follow-up tests would be 
conducted, and the configuration would be retrofitted to previously 
assembled units and applied to all new units moving forward, similar to 
the process for a running change in crashworthiness NCAP.
    Overall, most commenters agreed with the Agency's approach, in 
part, but suggested an alternative number of trials or maximum speed 
threshold would be more appropriate.
Number of Test Trials/Repeat Trials
    In relation to number of test trial and repeat trials, several 
commenters stated the Agency should adopt an alternative number of test 
trials to assess each test speed. DRI and Subaru were two such 
commenters, with both stating at least two trials should always be 
completed. DRI stated if the first trial ended in a contact with an SV 
impact speed of 50 percent of the initial speed or greater, a full set 
of five trials would be completed. However, if the SV avoided the 
pedestrian mannequin or impacted at less than 50 percent of the initial 
speed, one confirmatory repeat trial would be conducted. DRI explained 
if the results of the confirmatory trial were the same as the initial 
trial, then that scenario/speed would be complete. However, if the 
results differed, then three more trials would be conducted for a total 
of five trials. DRI explained this approach may potentially identify 
vehicles that inconsistently detect pedestrians and would eliminate 
``luck of the draw'' results. The laboratory also noted anecdotal 
evidence from its testing experience suggesting there may be vehicles 
which cannot reliably detect pedestrians, but they perform very well 
otherwise. Subaru suggested that NHTSA harmonize with JNCAP's method of 
testing, which entails running three trials for each vehicle speed. 
Subaru stated trials at a given SV speed could be stopped at two if the 
vehicle avoided contact twice in a row or if the speed reduction rate 
was the same twice in a row.\258\
---------------------------------------------------------------------------

    \258\ Japan New Car Assessment Program (JNCAP) (Revised March 
23, 2022), Autonomous Emergency Braking System [For Pedestrian 
Daytime] Performance Test Procedure.
---------------------------------------------------------------------------

    Honda agreed with DRI that five trials should be performed if the 
SV contacts the pedestrian mannequin at 50 percent or greater of the 
initial speed. TRC expressed that three total trials would be 
sufficient, with only one failed run permitted. Auto Innovators opined 
multiple trials (i.e., for a three-out-of-five passing criterion) would 
be needed if a no-contact criterion is established since the Agency's 
research data showed that several vehicles had contact for one run but 
were able to avoid making contact for three out of five runs. An 
individual commenter expressed that seven trials would be more 
appropriate to ensure the systems work reliably and to harmonize with 
other ADAS test protocols proposed by NHTSA for NCAP.
    Two respondents, Toyota and Advocates, suggested that an 
alternative number of trials may be more appropriate for PAEB 
evaluations, without providing a specific number. Advocates suggested a 
greater number of trials may be appropriate, with the consumer group 
advising NHTSA to set stringent pass/fail criteria since real-world 
situations may vary and are not ideal. Advocates urged the Agency to 
take this into account when selecting the number of trials for each 
scenario, asserting that NHTSA must be confident that the technologies 
will operate as tested. Conversely, Toyota suggested that a reduced 
number of trials may be sufficient. The automaker emphasized the 
importance of minimizing the amount of testing wherever possible to 
provide timely information to consumers. It recommended carefully 
selecting the number of test trials (and test conditions) to ensure 
that enough relevant performance information is conveyed to interested 
parties.
    IDIADA reasoned the Agency's approach provided sufficient 
assurance, stating it was a ``good strategy'' to perform one run per 
test speed for multiple speeds and a range of scenarios since PAEB 
systems are robust. However, the laboratory did not support NHTSA's 
testing approach in its entirety. As discussed later, IDIADA commented 
that vehicles should completely avoid making contact with the mannequin 
target at initial test

[[Page 96000]]

speeds up to 40 kph (24.9 mph) and offer speed reductions of greater 
than 50 percent for initial test speeds greater than 40 kph (24.9 mph). 
Like IDIADA, HATCI also found NHTSA's proposed approach of one run per 
speed appropriate; however, they opined that vehicles should get credit 
for any passed runs up to the point of failure and for the speed 
reduction at failure. GM stated the Agency could conduct one trial per 
test speed up to 40 kph (24.9 mph) or until contact occurs. BMW also 
supported the Agency's approach of performing one run per test 
condition and four additional trials in the case of impact if NHTSA 
employed a no-contact criterion; however, the manufacturer preferred an 
assessment approach based on speed reduction. For this approach, BMW 
asserted that any impact should be followed by two confirmatory trials, 
with the median impact speed of the three trials being selected as the 
true impact speed for that scenario/speed. Conversely, Auto Innovators 
suggested that the Agency may only have to conduct one trial run per 
test speed if a speed reduction approach was adopted. However, Auto 
Innovators seemingly preferred an assessment approach requiring three 
out of five passing runs in such instances, like it advocated for in 
the event NHTSA adopted a no contact criterion (discussed prior).
Appropriate Maximum Allowable Impact Speed for Repeat Trials
    Three groups agreed with NHTSA's proposed allowable maximum impact 
velocity for additional testing: AAA, ASC, and HATCI. AAA noted testing 
experience suggests insufficient speed reduction in the first trial 
indicates a vehicle is unlikely to perform well in subsequent testing. 
ASC specifically stated its support of the 50 percent reduction in 
speed value, because at the upper end of the testing range (60 kph 
(37.3 mph)), the maximum allowable impact speed for additional test 
trials would be 30 kph (18.6 mph), which is lower than the pedestrian 
impact test speeds for crashworthiness pedestrian protection tests in 
Global Technical Regulation (GTR) No. 9 (40 kph (24.9 mph)).
    Other commenters, like Mercedes-Benz, Honda, Intel, IDIADA, Auto 
Innovators, and GM, objected to an assessment approach that 
discontinued testing based on a vehicle's inability to achieve complete 
crash avoidance for a specified test speed. These respondents suggested 
that the full battery of required test trials should be conducted for 
the entire speed range regardless of complete crash avoidance. More 
specifically, Honda and Intel expressed it would be overly stringent to 
discontinue testing when impact speed is greater than 50 percent of the 
initial test speed, as was proposed. Honda stated that four additional 
trials should be conducted in such instances, and Intel recommended 
that, if an incremental approach was adopted, NHTSA should continue to 
run trials at least one SV initial speed increment higher beyond the 
speed at which the vehicle is considered to fail, as long as the 
vehicle achieves full avoidance in at least one trial. Although Subaru 
generally agreed with the upper impact speed limit threshold, the 
automaker recommended that instead of discontinuing testing for impact 
speeds over 50 percent of the initial test speed, NHTSA should review 
in-house manufacturer data to determine whether this was an expected 
outcome. If the manufacturer data indicates that different performance 
was expected, then Subaru suggested additional trials should be 
executed.
    Auto Innovators also supported allowing testing to proceed in the 
event of contact and/or a speed reduction of less than 50 percent, 
suggesting the Agency utilize a three-out-of-five passing criterion in 
such instances and assign partial credit for vehicles that perform well 
at higher speeds. For lower initial test speeds (i.e., less than 40 kph 
(24.9 mph)), the group, along with Honda, suggested incremental testing 
should proceed regardless of impact speed. Honda expressed this would 
limit the influence of potential variation in test conditions and would 
be consistent with approaches used by other global NCAPs to determine 
the maximum allowable impact speed. The manufacturer explained that 
Euro NCAP discontinues testing when the SV impact speed reduction is 
less than 15 kph (9.3 mph) for initial test speeds over 40 kph (24.9 
mph), and JNCAP discontinues testing if impact speed exceeds 40 kph 
(24.9 mph) over two test runs. Auto Innovators asserted some vehicles 
may not achieve full avoidance at lower speeds due to sensor viewing 
angles and suggested that NHTSA's proposed method of discontinuing the 
test in this case would unfairly penalize a vehicle manufacturer and 
might not convey the system's full capability. Subaru also stated that 
poor performance at lower speeds should not automatically disqualify a 
vehicle from earning partial credit for better performance at higher 
speeds.
    Like other commenters, GM supported continued testing upon contact. 
The manufacturer cautioned that a single failure should not result in 
the full penalty of no credit when there is potential test variation 
introduced at higher speeds or with obstructions present. GM stated 
that the pass/fail penalty should be applied over the entire set of 
test runs instead of individual runs. Alternatively, the manufacturer 
suggested the Agency could adopt pass/fail criteria based on a minimum 
nominal speed reduction, an approach also supported by Tesla, FCA, and 
Aptiv. FCA and Aptiv noted that a 50 percent reduction when the initial 
test speed is 40 kph (24.9 mph) or greater would be too stringent and 
instead suggested that a more appropriate speed reduction to accept for 
these higher initial speeds would be 20 kph (12.4 mph) since the 
ensuing impact speed would fall below the GTR No. 9 crashworthiness 
test speeds, (40 kph (24.9 mph)). Aptiv stated their comment was based 
on statistics showing pedestrian fatalities and injuries are ``greatly 
reduced'' below 40 kph. Along similar lines, assuming contact was 
allowed, the League advocated for a maximum impact speed of 25.7 kph 
(16 mph) based on a study by the AAA showing the average risk of severe 
injury for a pedestrian struck at this speed is 10 percent.\259\
---------------------------------------------------------------------------

    \259\ Tefft, B.C. (2011). Impact Speed and a Pedestrian's Risk 
of Severe Injury or Death (Technical Report). Washington, DC: AAA 
Foundation for Traffic Safety.
---------------------------------------------------------------------------

    As with other aspects of the PAEB testing protocol, Advocates 
requested NHTSA provide data and analyses to support its decisions for 
test specifications, noting the information the Agency provides must be 
sufficient for consumers to accurately and reliably compare vehicle 
performance.
Response to Comments and Agency Decisions
    As mentioned previously, NHTSA has decided to proceed with adopting 
a testing approach for PAEB that is similar to, but not identical to, 
that which the Agency proposed. For each test condition, the Agency 
will increase test speeds in 10 kph (6.2 mph) increments from the 
minimum test speed to the maximum, conducting one trial for each 
required speed. In the event the SV contacts the pedestrian mannequin 
during the initial run for any test speed, testing will cease for the 
test condition, respective test scenario, and PAEB testing for the 
particular lighting condition overall. Vehicles must pass all required 
trial runs (i.e., one per test speed) to receive PAEB credit for the 
relevant lighting condition on NHTSA's website.

[[Page 96001]]

Number of Test Trials/Repeat Trials
    Although several commenters recommended the Agency perform multiple 
trials (e.g., two, three, five, seven, etc.) for each test condition, 
often with the number of recommended trials varying based on the 
initial test speed, impact speed, or prior results, NHTSA has made the 
decision to run only one valid trial per test condition. This decision, 
which aligns with that adopted for AEB testing, is appropriate for 
several reasons.
    First, a testing approach that requires one trial run per test 
condition instead of multiple runs allows the Agency to limit test 
burden while also performing tests for a greater number of conditions 
that represent real-world crashes involving pedestrians. Under the 
Agency's final PAEB test matrix, NHTSA will conduct (at most) 36 test 
trials for testing in daylight conditions and 34 trials for the testing 
in dark lighting conditions, for 70 trials total. This is far fewer 
than the number of trials that would be required if the Agency were to 
adopt an approach that required multiple trials for each of the six 
adopted PAEB test conditions as is prescribed for NCAP ADAS testing 
currently. For instance, NCAP's current AEB test procedure requires a 
minimum of five passing trials out of seven conducted to pass a given 
test condition, for a total of up to 42 trials for a CIB test and up to 
56 trials for a DBS test. Adopting a similar approach for PAEB, as one 
commenter suggested, would require that up to 350 total trials be 
conducted, resulting in a significant burden to both vehicle 
manufacturers and NHTSA. Choosing instead to conduct one trial per test 
condition creates a test burden more comparable to NCAP's current AEB 
testing.
    Given this decision, it is not necessary to proceed as several 
commenters suggested and select only certain scenarios and/or test 
speeds, whether pre-selected or chosen at random, to verify system 
performance. Such an approach may limit burden, but it would not best 
ensure system functionality or robustness. Likewise, it is unnecessary 
to accept manufacturer data and spot-check system performance for only 
certain test condition/speed combinations, as several commenters 
suggested. NHTSA reasons that its reduced testing approach should 
ensure acceptable system performance across a range of real-world 
conditions without sacrificing program integrity. This finalized test 
method of limited trials should also allow NHTSA to communicate 
valuable information more quickly to consumers, as Toyota requested.
    The Agency's decision to conduct one trial per test condition/speed 
combination should also limit consumer confusion and better instill 
confidence and reliability in a vehicle's PAEB system. As mentioned 
earlier for AEB, allowing repeated trials in the event of contact may 
mislead consumers into thinking that a vehicle's AEB system provides 
more repeatable, robust performance than it does. Providing consumers 
with an assessment of system performance that is a single, 
representative sample rather than an assessment based on a best three 
out of five approach therefore seems most appropriate. And, while Auto 
Innovators contended that vehicle performance in the Agency's research 
tests suggests that multiple runs (i.e., for a three-out-of-five 
passing criterion) are necessary if a no-contact criterion is adopted, 
NHTSA disagrees with this assertion. Although several vehicles made 
contact in many runs, one vehicle afforded complete crash avoidance in 
63 out of the 70 total adopted test condition/speed combinations. This 
suggests that consistent, repeatable performance is possible for more 
robust PAEB systems, and that any poorer performance was something 
manufacturers could remedy. To best address the safety need, the Agency 
concludes it should devise passing performance thresholds that 
encourage design improvements to match the system performance afforded 
by the best fleet performers (i.e., those that provide no contact 
during the first trial run for a large number of test conditions) 
rather than to establish a performance threshold based on the average 
or worst performers.
    While some commenters expressed that the Agency should perform 
multiple trials for each test condition to ensure system reliability 
(albeit often with contact permitted), the Agency asserts, as it 
conveyed for AEB, that requiring one trial run per test condition 
instead of multiple runs is appropriate given its decisions to 
increment test speeds by 10 kph (6.2 mph) from a minimum speed to a 
maximum speed (as discussed earlier) and to disallow contact (as 
discussed next) for the PAEB tests. NHTSA reasons this approach will 
effectively identify system inconsistency and adequately address DRI's 
concern regarding ``luck of the draw'' results. The Agency's planned 
incremental testing approach, which uses relatively small speed 
intervals, is inherently designed to expose unreliable systems and 
ensure system reliability without the need for confirmatory runs, as 
the test laboratory suggested. If an inferior system happens to succeed 
at one speed, it will likely not continue to be ``lucky'' for the 
entire test series for a test condition (or for subsequent test 
conditions) as speeds are increased and test stringency increases. 
Since a failure of any one run at any given speed for any one test 
condition will result in an overall test failure for the tested PAEB 
system in that particular lighting condition, this approach is 
sufficient to serve as an acceptable gauge of system robustness. 
Furthermore, the slight increase in test speed from one trial to the 
next effectively provides the same benefit of assuring reliability as 
multiple runs conducted at the same speed. By adopting this testing 
method, consumers should feel confident that a vehicle that receives 
PAEB credit on NHTSA's website for a given lighting condition will 
operate consistently during a myriad of real-world driving situations 
in which consumers will likely be involved, as Advocates had requested.
    Adopting the testing approach of conducting one run per test 
condition is viable even though CAS asserted that ``passing five of 
five tests provides only 86% reliability with 50% confidence.'' The 
Agency notes that while its final testing approach may be limited in 
that it does not ensure absolute reliability of system performance with 
100 percent confidence, it is also unreasonable to impose the number of 
runs for each PAEB test speed that would be required to achieve this 
level of certainty. The test burden for NHTSA would increase 
exponentially.\260\ While NHTSA could alternatively consider conducting 
a significant number of runs (i.e., more than 20) at only the highest 
test speed for each test condition (i.e., 40 kph (24.9 mph) for S1d 
testing in darkness and 60 kph (37.3 mph) for all other PAEB test 
conditions in daylight and darkness), as the Agency mentioned prior for 
AEB, it would risk imparting additional damage to the test vehicle and 
test equipment in addition to test delays if it was to take such an 
approach. As such, NHTSA's planned test method affords the most 
balanced approach to ensure system reliability with an acceptable 
degree of

[[Page 96002]]

confidence. Furthermore, as will be discussed later, the Agency has 
adopted a criterion of ``no contact,'' like CAS requested, which should 
further help to address the organization's concerns.
---------------------------------------------------------------------------

    \260\ Using the binomial distribution to determine sample size 
for a given reliability and confidence level, 300 trials would be 
needed for 99 percent reliability with 95 percent confidence. See 
https://reliabilityanalyticstoolkit.appspot.com/sample_size. 
Similarly, 59 trials would be needed for 95 percent reliability with 
a 95 percent confidence, and 29 trials would be needed for 90 
percent reliability with 95 percent confidence. Since the vehicle 
tested is randomly purchased or leased from dealerships, its 
performance in the AEB tests is based on the performance and 
manufacturing reliability set by the manufacturer.
---------------------------------------------------------------------------

Maximum Allowable Impact Speed for Repeat Trials
    NHTSA originally proposed conducting multiple trials and requiring 
a three-out-of-five pass rate for instances where the relative 
longitudinal velocity between the SV and pedestrian mannequin was less 
than or equal to 50 percent of the initial speed of the SV during an 
initial trial at any one test speed. However, based on the results from 
the Agency's recent model year 2021-2022 PAEB research tests, it is now 
unacceptable to award credit to PAEB systems with inferior performance 
that may allow impact with pedestrians at some frequency when other 
systems are able to avoid contact for most test conditions. To maximize 
safety impact, NHTSA must establish performance criteria for testing 
that will ensure AEB system response is consistent and repeatable. As 
such, like decisions made for AEB NCAP testing, NHTSA will not conduct 
repeat PAEB trials in the event of SV-to-pedestrian mannequin contact 
regardless of the relative longitudinal impact velocity recorded 
between the vehicle and the pedestrian mannequin at the time of impact. 
Instead, PAEB testing for a given lighting condition will cease at the 
first instance of contact. The Agency is making this decision while, at 
the same time, acknowledging that many commenters supported conducting 
additional PAEB test trials when a 50 percent speed reduction or less 
is observed in the first trial run or subsequent trial runs for a 
particular test speed.
    For example, ASC expressed that a 50 percent reduction in speed was 
acceptable since the maximum allowable impact speed at the highest PAEB 
test speed (60 kph (37.3 mph)) would be 30 kph (18.6 mph), and this 
speed is lower than the 40 kph (24.9 mph) pedestrian impact test speed 
specified for crashworthiness pedestrian protection tests in GTR No. 9. 
However, the Agency would be remiss to tolerate any amount of vehicle-
to-pedestrian contact in the PAEB NCAP tests given the possibility of 
serious injury or death resulting from low-speed crashes. Furthermore, 
NHTSA agrees with AAA's concerns that vehicles that cannot provide 
complete crash avoidance in one trial are unlikely to avoid contact in 
subsequent, higher-speed trials, with the exception of trials initiated 
at 10 kph (6.2 mph). Discontinuing follow-up testing for these vehicles 
should limit potential damage to the vehicle, pedestrian mannequin, and 
test equipment, thus avoiding expensive or time-consuming interruptions 
or repairs during NCAP assessments and limiting repeatability concerns. 
For these reasons, the Agency also does not see a need to proceed as 
Subaru suggested and conduct repeat trials for impact speeds over 50 
percent of the initial test speed for those vehicles exhibiting 
performance that differs from manufacturer data.
    For similar reasons, it is not appropriate to adopt an alternative, 
and essentially less stringent, speed reduction, like 20 kph (12.4 
mph), for speeds greater than 40 kph (24.9 mph), as suggested by FCA 
and Aptiv. While it is true that the resultant maximum impact speed (40 
kph (24.9 mph)) resulting from the maximum initial test speed (60 kph 
(37.3 mph)) is equivalent to the GTR No. 9 crashworthiness test speed 
and the likelihood of being killed or seriously injured at impact 
speeds below 40 kph (24.9 mph) is reduced, it is not negated; injuries 
and fatalities still occur at impact speeds ranging from 20 kph (12.4 
mph) to 40 kph (24.9 mph). NHTSA's crash data shows that, on average, 
22 percent of pedestrian injuries and 8 percent of pedestrian 
fatalities occur yearly on roads with posted speeds 40 kph (24.9 mph) 
and under.\261\ Likewise, NHTSA does not agree with adopting a pass/
fail criterion based on a minimum nominal speed reduction, as GM and 
several others suggested, or a maximum impact speed, as the League 
submitted. Adopting a testing approach which accepts a 10 percent 
chance a pedestrian may incur a severe injury, as the League suggested 
for a 27.5 kph (16 mph) maximum impact speed, is objectionable when 
systems capable of producing no injuries in the scenarios examined 
exist in today's fleet.
---------------------------------------------------------------------------

    \261\ Swanson, E., Foderaro, F., Yanagisawa, M., Najm, W.G., & 
Azeredo, P. (2019, August), Statistics of light-vehicle pre-crash 
scenarios based on 2011-2015 national crash data (Report No. DOT HS 
812 745), Washington, DC: National Highway Traffic Safety 
Administration.
---------------------------------------------------------------------------

    The Agency disagrees with the assertions of many commenters that it 
would be overly stringent or incomplete to discontinue testing upon 
contact in a single run and/or when a specific speed reduction was not 
achieved instead of proceeding with incremental testing through the 
full battery of required test trials. NHTSA's main objectives--to 
promote robust PAEB system designs, maximize safety potential, and 
prevent damage during testing--are best met by implementing a no 
contact criterion for each trial run, as CAS and Adasky asserted. This 
applies even to those runs conducted at low initial test speeds. NHTSA 
recognizes that Subaru and Auto Innovators objected to discontinuing 
testing when poor performance was observed at low initial test speeds, 
with the latter commenter contending that such an approach would 
unfairly penalize a vehicle and not convey the system's full 
capability. However, assuring robust performance across all speeds is 
imperative to maximize safety, especially considering a large number of 
pedestrian crashes occur at similar speeds to those adopted. The 
Agency's planned testing approach (i.e., conducting one trial per test 
condition across a wide range of test speeds and scenarios and adopting 
a no contact performance requirement) provides a more complete 
assessment of system capability and is the most appropriate method to 
ensure system reliability and confidence. Since vehicles will not be 
given multiple opportunities to provide passing performance but will 
instead be required to perform well on the first try, the Agency's 
approach should allow consumers to feel confident that a vehicle that 
receives PAEB credit for a given lighting condition on NHTSA's website 
will operate consistently in the real-world driving situations they 
will likely encounter, as Advocates requested.
    The Agency also does not concur with GM's assertion that test 
variations introduced at higher speeds or with obstructions present may 
result in questionable test conduct such that it would unfairly 
penalize a vehicle to discontinue testing based on a single run 
failure. NHTSA imposes tolerances on vehicle and target speeds, 
accelerations, positions, etc. to eliminate such concerns. Furthermore, 
it expects that PAEB systems that pass the selected tests should offer 
robust overall performance such that slight deviations from exact test 
specifications, which will likely be encountered during real-world 
driving, should not result in vastly different system performance. For 
this reason, it is appropriate that failure in a single trial will 
result in an overall test failure for a given lighting condition. 
Robust system performance is needed to ensure safety potential is 
realized.
    NHTSA will conduct PAEB tests in a prescribed order for its NCAP 
testing, generally moving from least stringent to most stringent, based 
on the Agency's experience gained during research testing. For a given 
lighting condition, PAEB testing will proceed as follows: S4c, S4a, 
S1b, S1a, S1e, S1d. For each

[[Page 96003]]

condition, testing will begin with an SV speed of 10 kph (6.2 mph) and 
will increase incrementally by 10 kph (6.2 mph) until either (1) the SV 
fails to fully avoid the pedestrian mannequin or (2) the SV reaches the 
maximum test speed for that condition. If the SV successfully avoids 
the pedestrian mannequin for a full battery of tests under one 
condition, testing will move to the next test condition. However, if 
the SV contacts the pedestrian mannequin, testing for that condition 
(as well as all subsequent testing for the applicable lighting 
condition) will cease. The Agency expects that, by using this approach, 
damage to both the pedestrian mannequins as well as to the SVs will be 
minimized, thus limiting costly and time-consuming repairs and delays.
    Since NHTSA is proceeding with a pass/fail approach designed to 
provide a comprehensive assessment across a range of test speeds and 
multiple test conditions with no contact, it does not see a need to 
finalize Intel's request to conduct at least one trial for the 
subsequent speed increment beyond the speed at which a vehicle first 
fails in instances where the vehicle achieves full avoidance in at 
least one of the prior trials. Such vehicles would fail the Agency's 
PAEB test for the given lighting condition at the first instance of 
contact. This test plan, including the order in which test conditions 
are carried out, may be amended should the Agency's assessment method 
change in the future.
5. No Contact Versus Speed Reduction
    For PAEB performance criteria, NHTSA proposed that a vehicle must 
achieve complete crash avoidance (i.e., have no contact with the 
pedestrian mannequin) to receive credit for a test trial conducted at 
each specified test speed (i.e., 10, 20, 30, 40, 50, and 60 kph (6.2, 
12.4, 18.6, 24.9, 31.1, and 37.3 mph)) for each test condition (S1a-e 
and S4a-c). NHTSA believed that this approach, used in conjunction with 
an incremental increase in SV speed (as discussed earlier), would limit 
damage to the pedestrian mannequin and the SV during testing. As an 
alternative, however, the Agency sought comment on whether it should 
require minimum speed reductions or specify a maximum allowable SV-to-
mannequin impact speed for any or all proposed test conditions (i.e., 
test condition and variant/test speed combination).
Summary of Comments
No Contact
    Some commenters agreed with the Agency that the no contact 
criterion was appropriate for the proposed PAEB test conditions. AAA 
found the no contact criterion unambiguous and straightforward, 
qualities that would be helpful in evaluating performance, a sentiment 
echoed by Adasky. The League commented that avoiding contact is the 
only way to ensure that death or serious injury does not occur. The 
remaining commenters that shared this viewpoint commented that, by 
requiring no contact, the Agency would insure against real-world, 
challenging situations that are not as controlled as NHTSA's test 
protocol. CAS, Uhnder, ASC, and Adasky mentioned that pedestrians in 
the field are diverse, and it would be impossible to ensure the public 
at large's safety without a no contact criterion. As mentioned earlier, 
CAS also asserted that a no contact criterion is necessary because 
``passing five of five tests provides only 86% reliability with 50% 
confidence.'' From a logistical standpoint, TRC noted that this would 
be a welcomed approach since the test mannequins and equipment could 
receive significant damage during pedestrian testing. Specifically, a 
no-contact criterion would alleviate concerns about equipment 
durability, particularly for higher-speed (greater than 60 kph (37.3 
mph)) testing.
No Contact at Low Speeds, Speed Reduction at Higher Speeds
    A few groups favored requiring no contact for tests with initial 
test speeds of 40 kph (24.9 mph) or less and allowing speed reduction 
for tests with initial test speeds above 40 kph (24.9 mph). These 
included Aptiv, Advocates, IDIADA, GM, and Intel. GM stated that the 
current state of technology does not support full avoidance at all 
speeds but that it is currently possible in the proposed test 
conditions up to 40 kph (24.9 mph). Beyond 40 kph (24.9 mph), GM 
suggested that the vehicle should be evaluated based on the amount of 
speed reduction achieved. Advocates acknowledged that no-contact 
results are preferable but noted that speed reduction offers meaningful 
safety benefits and should be encouraged at higher speeds. The group 
did not offer a speed at which to require speed reduction versus no 
contact but encouraged NHTSA to determine an appropriate threshold. 
Advocates further stated that vehicles which offer a speed reduction 
benefit should be given credit in some form. Aptiv suggested that full 
avoidance could be required for more simple conditions (e.g., non-
obstructed adult crossing), but not for more difficult ones (e.g., S1d, 
child obstructed by parked vehicles). Intel had similar comments 
regarding test condition S1d, since the child becomes visible only 1.4 
seconds pre-collision. The company suggested that NHTSA should offer 
full credit for a 40 kph (24.9 mph) speed reduction from a 60 kph (37.3 
mph) initial test speed for this condition. Further, Intel stated that 
there is a clear safety benefit in reducing impact speed by 20 kph 
(12.4 mph) to 30 kph (18.6 mph) at initial test speeds above 40 kph 
(24.9 mph). Finally, from a logistical standpoint, IDIADA mentioned 
that pedestrian mannequins can withstand impacts up to 40 kph (24.9 
mph) with minimal damage.
    Many commenters reiterated the safety benefit that speed reduction 
can offer, with Toyota, BMW, Bosch, Honda, IIHS, Mercedes-Benz, GM, 
Rivian, DENSO, Auto Innovators, HATCI, and Subaru highlighting the 
advantages of speed reduction in their comments. Toyota suggested that 
NHTSA move away from a pass/fail criterion to a performance-based 
metric, which the manufacturer suggested may allow NHTSA to reduce the 
number of test trials required to evaluate vehicles. The automaker also 
noted that reduction in impact speed would be a suitable measure of 
performance to distinguish one vehicle from another and corresponds to 
real-world performance and injury risk. Toyota noted this performance-
based metric could also drive improvements in system capabilities. 
These sentiments were echoed by most of the commenters mentioned above. 
For example, IIHS asserted if the Agency requires no contact, 
manufacturers may not equip their vehicles with systems that can offer 
injury-mitigating speed reduction, or it may lead to more false-
positive activations. Tesla also echoed IIHS's concern regarding 
increased false positive interventions which pose risks of their own as 
manufacturers attempt to identify applicable situations as early as 
possible. The manufacturer went on to state that a ``fine-tuned'' speed 
reduction requirement strikes a balance between injury mitigation and 
reduction of false positives in the field. Rivian mentioned that by 
providing credit for impact speed reduction, NHTSA may encourage 
manufacturers to invest in technologies over time rather than 
abandoning them upfront if they cannot achieve the no contact 
requirement. Many others, including Auto Innovators, Honda, Mercedes-
Benz, and Bosch, asserted that any speed reduction should be rewarded 
with partial credit. Like Rivian, these commenters referred to Euro 
NCAP's sliding scale method of issuing points

[[Page 96004]]

for reduced impact speeds. GM also backed a sliding scale assessment 
approach based on speed reduction for test speeds over 40 kph (24.9 
mph), and HATCI supported assigning partial credit when a vehicle can 
meet the imposed performance requirements for only certain test speeds, 
as well as when a vehicle fails to meet the performance requirements 
(i.e., greater than 50 percent speed reduction) at a specific test 
speed as long as it provides some degree of crash mitigation. HATCI 
requested that NHTSA harmonize with Euro NCAP's performance evaluation 
method to the extent possible. DENSO suggested that speed reduction be 
tested in a range of conditions and referred specifically to 
evaluations in both Euro NCAP and U.N. Regulation No. 152, ``Uniform 
provisions concerning the approval of motor vehicles with regard to the 
Advanced Emergency Braking System (AEBS) for M1 and N1 vehicles.''
Other Suggestions
    Two commenters offered an alternative to speed reduction or no-
contact: crash avoidance via steering. ZF Group and Intel suggested 
that the Agency should allow manufacturers to pass scenarios 4a-c by 
using avoidance maneuvers instead of deceleration. ZF Group noted that 
ESS systems can support crash avoidance in various longitudinal 
scenarios.
    Two other commenters, Bosch and MEMA, specifically discussed Euro 
NCAP's method of determining contact and impact speed, indicating their 
support for the use of a virtual box around the articulated pedestrian 
mannequin to account for the movement of the mannequin's arms and legs, 
similar to that specified in Euro NCAP's AEB VRU test protocol. Both 
groups stated that SV contact or impact speed, if any, should be 
determined based on this virtual box.
    Finally, two individuals responded to this topic with suggestions 
to take individual vehicle design into account when determining contact 
or speed reduction criteria. Specifically, these individuals suggested 
that the Agency take vehicle mass into account since heavier vehicles 
traveling at a given speed will impart more force to a pedestrian than 
a lighter vehicle would at the same speed.
Response to Comments and Agency Decisions
    NHTSA is adopting a ``no contact'' criterion for NCAP's PAEB 
performance test requirements. The Agency recognizes that this decision 
conflicts with the recommendations made by a number of commenters, many 
of which supported the benefits of a performance criterion based on 
speed reduction. Notably, the respondents reasoned that a speed 
reduction criterion, along with a sliding scale method of assessment 
like that used by Euro NCAP, would be a more suitable metric to permit 
performance comparisons among vehicles and encourage improved system 
capabilities. The Agency, however, agrees with respondents (including 
as AAA and Adasky) who stated that consumers can more easily understand 
a pass/fail metric like ``no contact'' compared to a criterion based on 
speed reduction. Thus, NHTSA reasons this criterion should simplify 
vehicle performance evaluations. NHTSA is also of the opinion that 
complete avoidance is likely the result that most consumers expect from 
PAEB systems. Further, restricting assignment of PAEB credit to only 
those vehicles that offer superior system performance will also best 
assure that future designs offer meaningful improvements.
    The Agency does not agree with IIHS that vehicle manufacturers may 
not equip their vehicles with PAEB systems if NHTSA chooses to adopt a 
no contact performance requirement. For the model year 2024 light 
vehicle fleet, 94 percent of vehicles are equipped with standard PAEB 
systems. Based on this, the probability that manufacturers of these 
models will remove existing sensors used for pedestrian detection or 
fail to improve PAEB system capabilities simply because the Agency has 
adopted a stringent performance requirement for its voluntary consumer 
information program (i.e., NCAP) seems unlikely. Today's consumers 
expect technological advancements, whether they be related to 
infotainment, safety, autonomous driving, or otherwise. Because of 
this, the Agency also doubts other manufacturers would abandon pursuit 
of PAEB technology because they are unable to achieve a no contact 
performance threshold upfront, as Rivian suggested. Instead, as other 
commenters contended, adoption of a no contact performance metric will 
likely encourage development of superior systems that provide robust 
performance in NHTSA's testing, a feat that is reasonably attainable 
for vehicles in the near future using existing technology. In the 
Agency's 2021-2022 research, one vehicle model afforded complete crash 
avoidance in all but seven of the test conditions adopted herein, and 
four of the failed trials stemmed from failure of the vehicle to 
respond to the mannequin at 10 kph (6.2 mph).
    Several commenters cited the safety benefits inherent to speed 
reduction as a reason to adopt a speed reduction performance metric. 
While there are benefits to crash mitigation, there are more profound 
safety benefits afforded by PAEB systems that offer complete crash 
avoidance. Specifically, NHTSA agrees with the League that requiring 
vehicles to avoid contact with pedestrians is the only way to ensure 
that death or serious injury does not occur. Additionally, it would not 
be appropriate to adopt a no contact criterion for vehicle-to-vehicle 
testing (i.e., AEB) and allow contact for vehicle-to-pedestrian 
testing. A no contact requirement is especially important for 
pedestrian impacts since the consequences are more likely to be fatal. 
By promoting development of more robust PAEB systems capable of much 
higher speed reductions and complete crash avoidance, future systems 
may effectively address a larger percentage of crashes that cause 
serious injuries and/or fatalities.
    Like the related discussion earlier for AEB, a no contact 
performance metric has implicit benefits for NHTSA and manufacturer 
testing as well. As TRC asserted, imposing a no contact criterion in 
lieu of speed reduction better limits damage to the test vehicle, 
pedestrian mannequin, and test equipment during testing. Although the 
Agency acknowledges IDIADA's comments that mannequins may see ``minimal 
damage'' at impacts up to 40 kph (24.9 mph), contact between the 
pedestrian mannequin and test vehicle at low speeds can still cause 
sensor misalignment or test device degradation. Since such damage can 
influence test results and generate expensive or time-consuming delays 
or repairs to ensure repeatable testing, adoption of a no contact 
performance criterion better ensures the Agency is able to accurately 
verify manufacturer performance assessments in a timely manner.
    A few commenters suggested that a no contact performance criterion 
was unreasonable for current vehicles to meet, especially at higher 
test speeds. Others suggested that the Agency could require full 
avoidance for certain scenarios that they considered simpler (e.g., 
S1a-c and S1e) but not others (S1d) that they considered more 
difficult. Some respondents preferred that NHTSA adopt a speed 
reduction criterion in lieu of no contact and assign partial credit 
using a sliding scale (similar to Euro NCAP) for mitigation observed at 
higher initial test speeds. However, as mentioned, several vehicles 
from the current vehicle fleet were able to avoid contacting the 
pedestrian

[[Page 96005]]

mannequin for most of the test conditions adopted herein. For instance, 
one vehicle model provided complete avoidance in all crossing path 
scenarios except for the S1d test condition in both daylight and dark 
lighting assessments, and two vehicle models afforded complete 
avoidance in all daylight in-path scenarios. With minor system changes 
to improve performance, future versions of these vehicles would be able 
to pass the failed test conditions, thus proving a pass/fail metric is 
practical. Therefore, the Agency sees no need to condone inferior 
system performance by allowing contact when it can encourage the design 
and development of robust PAEB systems instead. As the referenced 
vehicle models have not received an increased number of false positive 
reports compared to other models, the Agency further reasons that its 
recent data also show that a no contact performance metric can be met 
at higher initial test speeds with no increase in false positive rates, 
which was a concern expressed by IIHS and Tesla. As mentioned 
previously for AEB, NHTSA plans to continue to use check marks to 
assign credit to vehicles that pass the performance test requirements 
adopted for each ADAS technology until such time as it publishes a 
notice to finalize a rating system for crash avoidance technologies. 
Therefore, it cannot award partial credit for speed reductions at this 
time, as a few commenters requested.
    As requested by Bosch and MEMA, NHTSA is adopting the ``virtual 
box'' specified in section 3.4.2 of Euro NCAP's AEB VRU test protocol 
\262\ to clearly define the area that accounts for the movement of the 
articulating pedestrian mannequin's arms and legs when determining 
contact. This virtual box is necessary to enable a fair assessment for 
all tested vehicles. At this time, however, NHTSA will not permit 
vehicles to pass NCAP's PAEB testing by utilizing steering to avoid 
impact instead of braking for S4a-c, as ZF Group and Intel recommended, 
or any of the other PAEB test conditions being adopted. Previously-
cited Volpe data showed that, for cases where driver avoidance maneuver 
was known, the driver made no attempt to avoid the crash (e.g., no 
braking, steering, accelerating) for 76 percent of pedestrian crashes 
involving fatalities and 70 percent of crashes involving 
injuries.263 264 Accordingly, adopting PAEB test 
requirements that require the vehicle to automatically brake in the 
absence of driver input, such as steering, is appropriate. This 
decision also aligns with that which the Agency has made in response to 
comments received surrounding evasive steering for NCAP's AEB tests. As 
thoroughly discussed previously, such factors as vehicle dynamics, 
traffic conditions, and traffic participants all influence the safety 
benefit of a steering avoidance maneuver. Steering, when used as an 
avoidance maneuver, may not be as safe as in-lane braking, particularly 
in an urban environment. Furthermore, allowing vehicles to use ESS 
during NCAP's PAEB assessments to avoid contact with the pedestrian 
mannequin would require the Agency to adopt additional tests to assess 
the functionality of ESS itself to prevent unintended consequences. 
While this may be considered as part of a later update, it will not be 
incorporated at this time. The Agency must first study the capabilities 
and limitations of systems meant to support the driver during these 
evasive maneuvers prior to incorporating such assessments in its NCAP 
testing. As such, NCAP will disable ESS systems prior to PAEB testing 
for those vehicles equipped with such systems, thus ensuring fairness 
for all vehicles, as only braking performance will be evaluated for 
all.
---------------------------------------------------------------------------

    \262\ European New Car Assessment Programme (Euro NCAP) 
(December 2023), Test Protocol--AEB/LSS VRU systems, Version 4.5.
    \263\ Swanson, E., Foderaro, F., Yanagisawa, M., Najm, W.G., & 
Azeredo, P. (2019, August), Statistics of light-vehicle pre-crash 
scenarios based on 2011-2015 national crash data (Report No. DOT HS 
812 745), Washington, DC: National Highway Traffic Safety 
Administration.
    \264\ Driver avoidance maneuver was either unknown or not 
reported for 24 percent of fatal pedestrian crashes and 52 percent 
of passenger crashes with injuries.
---------------------------------------------------------------------------

    Since NHTSA has decided to impose a no-contact performance 
criterion for NCAP's PAEB testing, it does not see a need to create 
more stringent requirements for heavier vehicles compared to lighter 
ones, as two respondents recommended. Regardless of the vehicle's mass, 
all vehicles will be required to completely avoid impact with the 
pedestrian mannequin. Therefore, the potential difference in the 
imparting force created at impact for vehicles of different weights is 
inconsequential.
    Finally, regarding Toyota's comment that adopting a speed reduction 
performance criterion could reduce the number of trials necessary for 
vehicle assessments and therefore reduce test burden, the Agency's 
planned testing approach, as previously discussed, effectively 
addresses this concern.
6. Appropriate Minimum Overall Pass Rate for PAEB
    NHTSA proposed to denote vehicles that are equipped with a given 
ADAS technology and which meet the Agency's applicable minimum ADAS 
performance requirements with a check mark instead of a more detailed 
sliding scale assessment until the publication of the final notice for 
the new ADAS rating system. NHTSA requested comments on the appropriate 
number of test conditions a vehicle must pass to be granted a check 
mark for PAEB, suggesting two-thirds of the total unique combinations 
of test scenarios and test speeds (i.e., test conditions) as a possible 
benchmark.
Summary of Comments
    Several commenters agreed with NHTSA's proposed benchmark. BMW, 
Honda, IDIADA, Intel, Uhnder, and Bosch stated that passing results for 
two-thirds of unique combinations should be required to attain a check 
mark, but some commenters added caveats to their comments. 
Specifically, BMW, Honda, and Bosch preferred assessments that took 
speed reduction into account in some manner. BMW stated this would 
allow for a more accurate rating of a system and would set the Agency 
up for easier tuning of rating scales in the future. Honda stated it 
only agreed to a two-thirds passing rate if each individual scenario/
speed combination took speed reduction into account. As mentioned 
earlier, the automaker reasoned that a no-contact criterion would be 
too stringent and not give credit to products that offer safety 
benefits. In a similar vein, Bosch suggested that any amount of 
mitigation should be rewarded and that vehicles should receive partial 
credit even if they do not meet the two-thirds minimum for a check 
mark.
    Auto Innovators did not support the two-thirds minimum for credit. 
However, like those mentioned previously, the group suggested that 
vehicles offering speed reduction should be given credit since they 
still provide a ``reasonable safety benefit.'' Auto Innovators also 
recommended that speed reduction should be used to determine pass/fail 
criteria, or alternatively, a sliding scale should be used as part of 
an overall PAEB rating. Adasky also referred to a rating system in its 
response to this topic, mentioning that the Euro NCAP method of 
weighting each category according to real-world factors would be 
preferred since some tests will have a larger target population than 
others. Rivian also mentioned it preferred a points-based

[[Page 96006]]

PAEB rating system requiring a minimum number of points to pass. 
However, Rivian stated if NHTSA were to move forward with a scenario-
based approach, the pass rate should be determined based on the 
complexity of each test. The automaker also suggested that NHTSA should 
require a greater passing percentage for simpler scenarios and a 
smaller passing percentage for more complicated or difficult scenarios.
    Citing the variety of real-world encounters that occur between 
vehicles and VRUs, CAS stated the pass rate for NHTSA's PAEB system 
testing should be 100 percent. However, the group mentioned that NHTSA 
could enhance the program by adding optional PAEB tests or by assessing 
test performance metrics like distance between the stopped vehicle and 
the test target. CAS explained this would allow consumers to identify 
strengths in vehicle performance rather than lowering the bar to give 
credit to vehicles that cannot pass all of NHTSA's tests.
    Three other groups (Toyota, Advocates, and GM) commented on this 
topic but did not provide specific acceptable pass rates. As mentioned 
earlier, Toyota urged NHTSA to use performance-based criteria wherever 
possible, instead of pass/fail criteria. Advocates suggested that the 
Agency set stringent pass/fail criteria given that the variety of on-
road conditions found in the field are not always represented in the 
ideal testing environment. Finally, GM noted that NHTSA should strike a 
balance between current PAEB system limitations and criteria informed 
by real-world pedestrian crash data to maximize potential safety 
benefit.
Response to Comments and Agency Decisions
    Since the Agency has opted to impose a no contact performance 
criterion for PAEB testing, it will not adopt a rating system based on 
speed reduction, as many commenters requested. Although BMW contended 
that such a rating system would be ``more accurate'' and allow NHTSA to 
make changes more easily to reflect future updates, the Agency reasons, 
as previously mentioned, that an assessment based on no contact can be 
more easily understood by consumers. Until a crash avoidance rating 
system is developed and finalized, those vehicles receiving a check 
mark will have met NHTSA's minimum level of performance, and those that 
do not display a check mark will have not.
    In the same vein, NHTSA has decided to adopt a pass rate of 100 
percent for NCAP's PAEB testing instead of the suggested two-thirds 
(i.e., 67 percent) benchmark. This decision aligns with the Agency's 
choice for AEB testing. PAEB systems must achieve passing results 
(i.e., no SV-to-pedestrian mannequin contact) in all adopted test 
conditions (i.e., 24 tests in daylight conditions and 22 in dark 
lighting conditions for S1--S1a, S1b, S1d, S1e, spanning speeds from 10 
to 60 kph (6.2 to 37.3 mph),\265\ and 12 daylight and darkness test 
conditions (i.e., 24 total) for scenario S4--S4a and S4c, spanning 
speeds from 10 to 60 kph (6.2 to 37.3 mph)) to receive credit for PAEB 
technology for each lighting condition. By requiring a 100 percent pass 
rate, the Agency concludes consumers will be able to quickly recognize 
which vehicles offer robust, repeatable PAEB system performance.
---------------------------------------------------------------------------

    \265\ S1d will be assessed in the nighttime lighting condition 
from 10 to 40 kph (6.2 to 24.9 mph).
---------------------------------------------------------------------------

    At this time, as mentioned, the Agency has decided to assign credit 
separately for PAEB system performance in daylight and dark lighting 
conditions; vehicles will not have to achieve passing performance for 
all 70 tests in daylight and dark lighting conditions collectively to 
obtain credit for PAEB overall. A vehicle must pass the 36 required 
test conditions in daylight to obtain credit for PAEB performance in 
daylight and must separately pass the 34 prescribed test conditions in 
dark lighting conditions to obtain credit for PAEB performance in 
darkness. The Agency has decided to evaluate PAEB performance in 
daylight and dark lighting conditions separately because no one vehicle 
tested as part of NHTSA's model year 2021-2022 research passed all test 
conditions (i.e., did not contact the pedestrian mannequin) for both 
daylight and dark lighting conditions. However, as mentioned, one 
vehicle exhibited nearly passing performance for each of the two 
lighting conditions.\266\
---------------------------------------------------------------------------

    \266\ For daylight conditions, the aforementioned vehicle failed 
only S1d at test speeds greater than 50 kph (31.1 mph) and S4a and c 
at 10 kph (6.2 mph). Similarly, for dark conditions, the vehicle 
failed only the S1d condition at test speeds greater than 40 kph 
(24.9 mph) and S4a and c at 10 kph (6.2 mph).
---------------------------------------------------------------------------

    By assigning credit separately for each of the two lighting 
conditions, the Agency's planned approach offers a compromise between 
the pass rate endorsed by several commenters (i.e., two-thirds or 67 
percent, albeit often with a speed reduction performance criterion 
instead of no contact) compared to that suggested by CAS (i.e., 100 
percent) for the proposed 70 unique PAEB test combinations. A vehicle 
that contacts the pedestrian mannequin for any of the required 34 PAEB 
test conditions when tested in the dark will not receive credit for 
PAEB performance in darkness; however, that same vehicle may still 
receive credit for PAEB performance in daylight if it offers complete 
crash avoidance for the required 36 PAEB test conditions when tested in 
the daylight. A vehicle could technically fail all 34 test conditions 
required for testing in darkness and still receive credit for PAEB in 
daylight, thus permitting an overall effective PAEB pass rate of just 
over 50 percent. Therefore, this approach aligns with Bosch's request 
to award partial credit for those vehicles that are not able to meet a 
two-thirds pass rate overall. It also provides additional useful 
information to certain groups of consumers that may not have otherwise 
been conveyed if the Agency had chosen to instead adopt a pass rate of 
100 percent for PAEB testing in both daylight and dark lighting, 
collectively. For instance, certain groups of consumers that drive 
primarily at night may find separate lighting-specific PAEB ratings 
particularly helpful. Likewise, consumers that rarely drive at night 
may not be deterred from purchasing a vehicle that does not perform 
well during NCAP's PAEB assessments in darkness. This decision also 
aligns with CAS's comment that the Agency should reward superior 
performance instead of lowering the bar so that more vehicles may 
receive credit. Although NHTSA has decided to require passing 
performance in only one lighting condition for this NCAP upgrade to 
receive partial credit for PAEB, this approach currently seems 
challenging for most vehicles given the results of its most recent PAEB 
research, even when considering a reduction in test speed for the S1d 
in dark lighting condition.
    Several commenters suggested alternative pass rates. Rivian opined 
that, if NHTSA adopted a pass-fail performance threshold, the pass rate 
for PAEB systems should be based on test complexity (i.e., a vehicle 
should be required to achieve passing performance for a greater 
percentage of test conditions for simpler scenarios compared to more 
complicated/difficult scenarios). Further, Adasky recommended that 
target populations for real-world crashes should dictate the weight 
assigned to each test scenario/condition. GM also suggested that real-
world crash data should be considered, in addition to current system 
limitations. Although there is merit to these suggestions, the Agency 
agrees with Advocates that it should establish stringent pass/fail 
criteria to ensure that

[[Page 96007]]

PAEB systems are robust and perform well during variations of the 
Agency's tested conditions, since the situations encountered during 
real-world driving will not always mirror the ideal testing 
environment. As such, only a 100 percent pass rate for each lighting 
condition ensures the development of optimal PAEB system designs. While 
capabilities may be limited for many current PAEB systems, as GM 
suggested, the results for one vehicle in the Agency's research testing 
exemplified system potential for future system iterations.
    Finally, at this time, the Agency will not adopt additional 
optional PAEB tests for extra credit, as CAS requested. NHTSA is 
considering the inclusion of other PAEB test scenarios in NCAP at some 
point in the future, such as turning scenarios and scenarios for 
bicyclists. These potential scenarios are discussed in a later PAEB 
section of this notice. However, the Agency is not considering program 
additions that align with CAS' second request--adding performance 
assessments based on the distance between the stopped vehicle and the 
test target. Because manufacturers must design PAEB systems that 
perform well in all real-world conditions, not just those assessed by 
NHTSA, the finalized NCAP test conditions should not be unduly 
prescriptive. Whether a vehicle stops several inches or several feet 
behind a pedestrian mannequin when tested seems irrelevant considering 
the outcome (i.e., complete crash avoidance) is the same. The Agency 
prefers to encourage manufacturers to expend additional resources into 
perfecting performance in all PAEB test conditions, both daylight and 
dark lighting conditions, as well as for the wide variety of other 
crash scenarios/conditions that may occur during real-world driving.
7. PAEB Warning, Including Signal Modality and Timing
    NHTSA is adopting the same FCW modalities outlined for NCAP's AEB 
test conditions for the program's PAEB test conditions. Specifically, a 
vehicle must present a forward collision warning to the vehicle 
operator via two sensory modalities--auditory and visual--to receive 
credit in each of NCAP's PAEB tests. Similar to AEB, while the Agency 
is requiring a an auditory/visual FCW, a vehicle may additionally 
present a haptic signal to warn of an impending collision without 
penalty. Adopting the same bimodal alert strategy for PAEB as NHTSA 
adopted for AEB is appropriate since standardization should ensure 
consumer familiarity and limit confusion. Drivers will be more likely 
to associate a dual-modality FCW with any sort of crash-imminent 
forward collision and, as such, should be more likely to respond with a 
timely and evasive action to mitigate or, if possible, avoid a crash 
altogether. This is especially important for crash-imminent situations 
involving pedestrians since they have no intrinsic protection.
    While the Agency will require the same dual-modality alert type for 
NCAP's PAEB tests as it's requiring for the program's AEB tests, it is 
making a distinction for the timing of the FCW. For PAEB testing, the 
FCW need not be issued prior to the onset of automatic braking, like 
was specified for AEB; the warning may be issued at any time before or 
during the automatic braking event. The Agency is making this 
distinction for PAEB because it recognizes the dynamics of some 
pedestrian crashes inherently result in a quick succession of events. 
For these crashes, it may be problematic to require the warning be 
followed sequentially by automatic braking. This was evidenced in the 
Agency's 2020 research testing, particularly for certain test 
conditions, such as S1d. The Agency's data showed automatic braking 
occurred nearly concurrent with, or prior to, the FCW for several of 
the Agency's test vehicles.\267\ Yet, many of these vehicles avoided 
contact with the pedestrian mannequin. Therefore, NHTSA hesitates to 
require sequential warning and braking functionality in order to not 
hinder system response time or alter system effectiveness. The Agency 
also does not want to encourage requirements that would drive forward 
collision warnings to be issued too early in response to potential 
pedestrian impacts since pedestrian movements can be unpredictable. 
Early warnings may have unintended consequences and lead to an increase 
in false positive activations. While FCWs issued prior to the onset of 
automatic braking are most desirable since they will serve to warn the 
driver of an impending crash and solicit a response, those issued after 
the onset of automatic braking can also be beneficial since they should 
serve to inform the driver that automatic braking is ongoing.
---------------------------------------------------------------------------

    \267\ As an example, when the S1d test condition was conducted 
for a model year 2020 Subaru Outback traveling at 16 kph, the onset 
of the FCW occurred at 0.92 sec. (FCW on time history plot) and 
automatic braking occurred essentially at the same time, at 0.91 
sec. (PAEB on time history plot). ``Final Report of Pedestrian 
Automatic Emergency Braking System Research Testing of a 2020 Subaru 
Outback Premium/LDD,'' https://www.regulations.gov/document/NHTSA-2021-0002-0002, See: Figure D66. Time History for PAEB Run 180, S1d, 
Daytime, 16 kph.
---------------------------------------------------------------------------

    During NCAP's PAEB tests, NHTSA will release the SV's accelerator 
(at any rate) within 500 ms after (1) issuance of the two required FCW 
signals (i.e., auditory and visual), or (2) the onset of automatic 
braking (as defined by the instant SV deceleration reaches at least 
0.15g), whichever is sooner.\268\ In either instance, the vehicle can 
pass a test trial if it does not make contact with the pedestrian 
mannequin and both signals for the bimodal alert are issued at some 
point prior to or during the braking event. While neither modality 
signal will be required prior to the onset of PAEB braking, both will 
be required prior to the end of the test for a vehicle to receive a 
passing result. If one or both of the signals required for the dual-
modality FCW are not issued and the vehicle's PAEB system does not 
offer any automatic braking (as defined by the instant SV deceleration 
reaches at least 0.15g), in a PAEB test, release of the SV accelerator 
pedal will not be required prior to impact with the pedestrian 
mannequin and the vehicle will fail the trial run. The driver (or 
throttle robot) will modulate the accelerator to maintain a constant 
speed until the end of the test occurs.
---------------------------------------------------------------------------

    \268\ The accelerator pedal will be released in a timely manner 
in either instance so as to not interfere with, and potentially 
override, the PAEB system, as this could affect test repeatability.
---------------------------------------------------------------------------

    It is reasonable to require that both FCW signals be issued before 
the end of the event in the Agency's PAEB tests because, as explained 
earlier, one of the two FCW signals which comprise a bimodal alert 
often serves as a secondary, confirmatory indication that explains to 
the driver what the primary signal is intended to communicate (i.e., a 
forward crash-imminent situation). Therefore, it seems prudent to 
assume these signals would be provided nearly concurrently, 
particularly given the dynamics of many pedestrian crashes and the 
limited time for intervention.
    The Agency is aligning other decisions for PAEB with those made for 
NCAP's AEB tests with respect to the FCW. NHTSA is not prescribing 
additional requirements for visual or auditory warnings (e.g., color, 
location, decibel level, type, etc.) and it is not standardizing PAEB 
warnings at this time.
8. User-Configurable Settings for PAEB Tests
    In its March 2022 RFC notice, the Agency proposed to test the 
middle (or next latest) FCW and PAEB system settings when assessing FCW 
and PAEB

[[Page 96008]]

as part of NCAP's PAEB tests for those vehicles that offer multiple 
timing adjustment settings.
    Since NHTSA has decided to evaluate FCW in tandem with PAEB 
(essentially, the SV must issue the required FCW signals at some point 
during the braking event), and the vehicle must not contact the 
pedestrian mannequin during testing, the tested FCW and PAEB system 
settings are important test variables. Effectively, to perform well in 
the Agency's PAEB evaluations, the vehicle must issue the FCW and brake 
automatically with sufficient time to allow the vehicle to avoid 
contacting the POV. As it decided for NCAP's AEB tests, the Agency will 
set the timing for the FCW and PAEB intervention to the middle (or next 
latest) setting (if adjustable) during its PAEB evaluations, like that 
previously shown in Figure 2. For FCW or PAEB systems having only two 
settings, the Agency will select the later of the two settings and this 
test setting will meet NHTSA's middle (or next latest) FCW/PAEB setting 
requirement. These system setting configurations align with Euro NCAP's 
AEB/LSS VRU systems test protocol. By integrating FCW assessments and 
adopting the middle (or next latest) system settings, NHTSA expects 
that vehicle manufacturers will inherently strive to limit nuisance 
alerts and PAEB activations during real-world driving for the timing 
settings preferred by most drivers while also performing well in NCAP's 
PAEB tests at this preferred setting.
    NHTSA is also imposing requirements for other system settings 
during NCAP's PAEB tests. For vehicles that have an ESC off switch, 
NHTSA will keep ESC engaged for the duration of the test. For vehicles 
offering regenerative braking, the Agency will select the ``off'' 
setting, or the setting that provides the lowest deceleration when the 
accelerator pedal is fully released for those vehicles offering 
multiple regenerative braking settings (e.g., less aggressive, nominal, 
more aggressive). This decision, which was also made for NCAP's AEB 
tests, should promote fairness and improve test execution, and thus 
test repeatability. NHTSA will also select the ``off'' setting for 
vehicles equipped with a one pedal operation mode in instances where 
those vehicles offer selectable settings for modes of operation. If one 
pedal operation cannot be disabled (i.e., regenerative braking is 
always enabled and one pedal operation cannot be switched ``off''), the 
vehicle will be tested with the moderate deceleration level ensuing 
from accelerator pedal release. For these vehicles, like all other 
vehicles, the accelerator pedal will still be fully released within 500 
ms after the FCW is presented or automatic braking (as defined earlier) 
occurs. In line with these decisions (and that made previously for 
NCAP's AEB tests), propulsion batteries will be charged at 80 percent 
or higher capacity during PAEB testing for electric vehicles, as 
performing assessments with a higher SOC should limit regenerative 
braking, and thus vehicle deceleration, when the accelerator is fully 
released.
    To receive credit for PAEB, forward collision warning and 
pedestrian automatic emergency braking technologies (i.e., FCW and PAEB 
systems) must appear `Default ON' during each ignition/key cycle. While 
the Agency is not prohibiting a disabling function for these 
technologies in its NCAP evaluation, it does not expect that the 
testing requirements imposed herein should result in reduced consumer 
satisfaction. Instead, NHTSA expects drivers will adjust their 
vehicle's FCW and PAEB system settings to meet their personal 
preferences instead of disengaging the system altogether.
9. Articulated Pedestrian Mannequins
    NHTSA proposed, and sought comment on, utilizing modern mannequins 
with moving legs instead of the posable pedestrian mannequins specified 
in its 2019 PAEB test procedure. The Agency explained that the 
articulating pedestrian mannequins are more representative of walking 
pedestrians and expected that more realistic targets would encourage 
development of PAEB systems that detect, classify, and respond to real-
world pedestrians more effectively and accurately. NHTSA's adoption of 
the articulating mannequin would also harmonize with Euro NCAP and 
IIHS, fulfilling the BIL's mandate that NHTSA ``benefit from 
harmonization with third-party safety rating programs.''
Summary of Comments
Adoption of the Articulating Mannequin
    Several commenters responding to the December 2015 notice favored 
the adoption of the articulating pedestrian mannequin, and most of the 
comments received in response to the March 2022 also favored its 
adoption and use in PAEB testing. Those in favor included TRC, MEMA, 
CAS, GM, The League, BMW, Bosch, FCA, Honda, Toyota, AAA, ASC, CCD 
Transportation Task Force, Rivian, Auto Innovators, Intel, HATCI, ZF 
Group, IDIADA, and one individual. Most of these commenters stated that 
articulating pedestrian mannequins are more representative of 
pedestrian gait and should be used. TRC noted that articulating 
pedestrian mannequins are the industry standard, a sentiment echoed by 
GM, BMW, FCA, Toyota, ASC, Auto Innovators, Intel, The League, and 
HATCI. GM added that ``the only means of measuring the potential added 
capabilities of [camera/radar] fusion systems, especially in low-light 
conditions, is to use the articulated pedestrian mannequin.'' Bosch, 
Auto Innovators, and HATCI noted that articulating pedestrian 
mannequins are preferable due to their Doppler spread and radar 
reflectivity characteristics and stated the performance measured with 
the static mannequins may not translate to real-world benefit. IDIADA 
also specified that radar-based systems monitor Doppler frequencies 
from leg movement. Some groups cited PAEB systems' algorithms (AAA) and 
artificial intelligence (FCA) as reason to utilize articulated 
mannequins. Honda added the ability to quickly identify a pedestrian 
and react accordingly is valuable, especially in situations with 
limited visibility or short reveal times. Intel agreed it is necessary 
for a PAEB system to identify pedestrians quickly and accurately. 
Rivian offered that accurate identification of pedestrians may reduce 
false positive activations. Finally, the League stated there is no 
benefit to adopting an unharmonized, fixed mannequin that is less 
lifelike.
    Though both BMW and Auto Innovators agreed that articulating 
pedestrian mannequins should be used in PAEB testing, they further 
requested that NHTSA use a black cover for the center tube for any PAEB 
assessments in dark lighting conditions the Agency may perform. The 
groups reasoned this change will further improve the mannequin's 
resemblance to an actual pedestrian in the dark. TRC also favored 
adoption of the articulating mannequins but requested detailed 
information on acceptable pedestrian target movement systems. The 
laboratory specifically noted there are currently belt and robotic 
platform systems available.
    Other commenters stated it is premature to include the articulated 
mannequins in NCAP and that other VRUs should be taken into account. 
Lidar Coalition, Velodyne, and two individuals urged NHTSA to account 
for all road users who are not walking, such as those in a wheelchair 
or scooter; those standing, pausing, or bending down; or those wearing 
clothing that obscures ambulation, such as a dress or robe. These 
commenters raised concern that PAEB systems may begin to over rely on 
leg movement as a VRU indicator. CCD Transportation Task

[[Page 96009]]

Force agreed that NHTSA should consider a variety of VRUs when choosing 
targets, adding that other groups may not be accurately represented by 
the pedestrian mannequin, such as women, shorter adults, and those with 
darker skin tones. Lidar Coalition, Advocates, and Velodyne stated that 
more data is needed to ensure the use of the articulating pedestrian 
mannequin will not have an adverse effect on these, or any other, VRU 
populations.
Response to Comments and Agency Decisions
    The Agency is adopting the 4activePA Adult and 4activePA Child 
pedestrian mannequins for NCAP testing.\269\ Commenters overwhelmingly 
favored the adoption of articulating, rather than static, mannequins 
for PAEB testing. In support of this stance, commenters cited 
harmonization, radar reflectivity characteristics, and realistic, 
lifelike movement, among other reasons. These pedestrian mannequins, 
used in NHTSA's research testing and utilized by Euro NCAP as part of 
testing conducted per its AEB/LSS VRU Systems test protocol,\270\ 
provide an accurate representation of real-life pedestrians, as 
commenters requested. The 4activePA Adult and Child mannequins have 
physical dimensions (i.e., size and shape) representative of a 50th 
percentile adult male and 7-year-old child, respectively, and are 
designed to produce a realistic response from radar, lidar, and camera 
sensors. Both mannequins have features representing hair, facial skin, 
hands, a long-sleeve black shirt, long blue pants, and black shoes. 
They also have articulating legs synchronized to the forward motion of 
the mannequin, replicate a human-like gait, and produce a realistic 
Micro Doppler effect. Unlike the legs of the pedestrian mannequin, the 
arms of the mannequins do not move, but are posable, and will be posed 
during testing. The 4activePA mannequins are also appropriate for NCAP 
testing because they are lightweight with a soft exterior to prevent 
vehicle damage upon impact.
---------------------------------------------------------------------------

    \269\ Both pedestrian mannequins are manufactured by 
4activeSystems.
    \270\ In Euro NCAP's AEB/LSS VRU Systems test protocol, the 
adult pedestrian mannequin is termed the Euro NCAP Pedestrian Target 
(EPTa) and the child pedestrian mannequin is termed the Euro NCAP 
Child Target (EPTc).
---------------------------------------------------------------------------

    NHTSA will utilize the 4activePA Adult mannequin for all PAEB test 
conditions that specify an adult test mannequin--S1a, S1b, S1e, S4a, 
and S4c; the 4activePA Child mannequin will be utilized for the S1d 
PAEB test condition. While the Agency recognizes it could utilize a 
posable pedestrian mannequin for the S4a test condition since the 
mannequin is stationary in those tests, NHTSA is adopting instead the 
articulating mannequin for S4a testing to promote test efficiency. As 
described later in this section, the 4activePA Adult mannequin will be 
confined to a standing posture position, with the legs at rest (i.e., 
static), for S4a tests. For all other test scenarios prescribing the 
adult mannequin (i.e., S1a, S1b, S1e, and S4c), the legs of the 
mannequin will articulate to simulate a walking or running motion, as 
appropriate. Similarly, for the S1d scenario, the legs of the child 
mannequin will be configured to articulate to simulate a running child.
    Since PAEB systems currently on the market may utilize camera-, 
radar-, and/or lidar-based sensors (or some combination thereof) to 
provide automatic emergency braking and prevent impact with 
pedestrians, the pedestrian test mannequins adopted for NCAP's PAEB 
testing must meet certain specifications to ensure the SV recognizes 
the targets, similar to real-world pedestrians, thus offering real-
world benefit. These specifications will also help assure test 
repeatability and reproducibility. Accordingly, NHTSA is adopting in 
its test procedures, certain specifications provided in several ISO 
standards for color (for camera-based sensors), physical dimensions 
(for camera- and lidar-based sensors), infrared reflectivity (for 
lidar-based sensors), and radar cross section and leg articulation (for 
radar-based sensors). The ISO standards are appropriate because they 
contain a large body of research testing to support the test devices. 
In most respects, these specifications also harmonize with those 
outlined by Euro NCAP in its ``Articulated Pedestrian Target 
Specifications'' document.\271\ The 4activePA pedestrian mannequins, as 
manufactured, meet these specifications.
---------------------------------------------------------------------------

    \271\ European Automobile Manufacturers' Association (ACEA), 
February 2016, ``Articulated Pedestrian Target Specification 
Document,'' Version 1.0, available at https://www.acea.auto/publication/articulated-pedestrian-target-acea-specifications/.
---------------------------------------------------------------------------

    First, the Agency is referencing many, but not all, of the 
specifications in ISO 19206-2:2018, ``Road vehicles--Test devices for 
target vehicles, vulnerable road users and other objects, for 
assessment of active safety functions--Part 2: Requirements for 
pedestrian targets.'' This standard addresses specifications for a test 
mannequin, including basic postures and body dimensions as well as leg 
articulation, infrared, and radar properties.
    Second, NHTSA is referencing sections of ISO 19206-4:2020, ``Road 
vehicles--Test devices for target vehicles, vulnerable road users and 
other objects, for assessment of active safety functions--Part 4: 
Requirements for bicyclists targets'' in NCAP's PAEB test procedures. 
This standard describes specifications for bicycle test devices 
representative of adult and child sizes. Although NHTSA will not use a 
bicycle test device during NCAP's PAEB testing at this time, this 
standard is being referenced solely because it contains sufficient 
specifications for color (i.e., the color of the mannequins' hair, 
clothes, skin, etc.) for the pedestrian test mannequins.
    NHTSA is also referencing in NCAP's PAEB test procedures sections 
of ISO 19206-3:2021, ``Test devices for target vehicles, vulnerable 
road users and other objects, for assessment of active safety 
functions--Part 3: Requirements for passenger vehicle 3D targets.'' 
This document provides measurement procedures for assessing radar 
cross-section.
    Lastly, NHTSA is referencing ISO 3668:2017, ``Paints and 
varnishes--Visual comparison of colour of paints,'' in NCAP's PAEB test 
procedures. This standard, which specifies a method to allow the visual 
comparison of the color of paints against a standard, will ensure the 
color of the pedestrian mannequins' hair, torso, arms, and feet are 
black, the color of the legs is blue, etc., as prescribed by ISO 19206-
4:2020.
    In addition to these requirements, the Agency will also require the 
placement of a black cover over the pedestrian mannequins' center 
vertical pole during PAEB assessments in dark lighting conditions, as 
Auto Innovators and BMW requested. NHTSA agrees that this should 
further improve the mannequin's resemblance to a real pedestrian. This 
modification should minimize contrast with the background and limit 
reflectivity to light sources (e.g., headlamps) during testing in dark 
lighting conditions. The radar reflectivity requirements prescribed in 
ISO 19206-2:2018 must be met both with and without the black cover 
present on the pole.
    Similar to its decision for the GVT, NHTSA is not adopting separate 
specifications for the pedestrian mannequin carrier system. The carrier 
system controls the speed (where applicable) and position (e.g., 
lateral overlap relative to the front of the SV and desired contact 
points) of the pedestrian test device. Since these variables will be 
subject to

[[Page 96010]]

specifications and tolerances prescribed for the pedestrian mannequins 
for each test scenario, NHTSA does not see a substantial need to 
specify which carrier system must be used to achieve the appropriate 
mannequin kinematics during testing. Further, the pedestrian mannequins 
will be assessed while mounted on the carrier system per ISO 19206-
2:2018, thus assuring the carrier system has a minimal radar cross-
section and minimal optical features based on the test environment. The 
Agency also notes that, at this time, it anticipates using the 
4activeSB robotic platform for NCAP testing.
    While NHTSA acknowledges the stance of a few commenters that the 
Agency should consider adding VRUs with different positioning/posture 
or clothing to not overly rely on leg movement to prompt system 
intervention, or different dimensions or skin tones to offer equivalent 
protection for all pedestrians, the Agency concludes the 4activa-PA 
Adult and Child pedestrian mannequins are acceptable for this NCAP 
upgrade. Although the Agency reasons it is important for PAEB 
performance requirements to ensure real-world safety benefits across a 
broad spectrum of pedestrian crash scenarios, it also recognizes that, 
for practical reasons, performance requirements cannot address every 
pedestrian crash scenario. Notwithstanding, the Agency is adopting test 
scenarios representing a walking, running, and standing adult. Further, 
NHTSA is incorporating a test scenario designed to simulate real-world 
pedestrian impacts involving children. Given this, the Agency expects 
future PAEB systems will effectively address pedestrians of various 
sizes and not rely solely on leg articulation for functionality. NHTSA 
will also continue to monitor real-world pedestrian crash data to 
ensure the adopted mannequins are reasonably sufficient to address the 
crash risks for pedestrians of other sizes, such as small adult women, 
and those having alternative postures. This data analysis should also 
allow the Agency to determine whether additional VRU surrogates or 
scenarios should be added to the Agency's PAEB test matrix in the 
future as representative test devices become available and research 
proves such devices to be robust and reliable during testing. Further, 
as discussed later in this notice, the Agency is considering adding 
additional test scenarios for bicyclists, motorcyclists, etc. in future 
updates to NCAP. NHTSA is also conducting research to assess the affect 
that variations in skin tone and/or clothing may have on PAEB system 
performance. NHTSA will compare these results to the referenced ISO 
standard specifications and may consider additions or modifications to 
improve the relevance of the Agency's PAEB tests once the research is 
complete.
10. Additional Test Procedure Refinements, Clarifications, and Feedback
    NHTSA requested comments on any areas of the proposed PAEB test 
procedure that needed clarification or further refinement before the 
Agency adopted it for use in NCAP. Various comments were received.
Summary of Comments
Publication of Draft Test Procedures
    Auto Innovators noted the draft test procedures have not been 
republished with changes suggested in response to a 2019 RFC 
notice.\272\ The group recommended that NHTSA republish the latest 
version of the procedures for comment and review.
---------------------------------------------------------------------------

    \272\ NHTSA-2019-0102-0011.
---------------------------------------------------------------------------

Pedestrian Mannequin Target
    Some commenters stated the characteristics of pedestrian mannequin 
target movement, like speed and acceleration of the mannequin as it 
moves across the test site, should be addressed. One individual stated 
the maximum pedestrian speed did not represent runners, as they may 
approach a vehicle's path more quickly. This commenter also noted the 
Agency could factor in safety for the variety of speeds at which VRUs 
travel by also varying the target speed. One individual commenter noted 
that seniors tend to move at a slower pace and are less likely to 
recover from injuries sustained in a vehicle impact, stating that 
seniors over the age of 65 are 35 percent more likely to be killed as 
pedestrians. NSC stated that older adults (those 65 and older) account 
for 20 percent of pedestrian fatalities.
    For target acceleration, vehicle manufacturers expressed logistical 
concerns. Honda, Toyota, and Auto Innovators requested the Agency 
ensure the pedestrian mannequin start and acceleration distances are 
adjusted to ensure the mannequins move smoothly across the surface. 
Commenters noted if the pedestrian mannequin is subject to sudden 
accelerations, it may ``shake,'' and its location and speed may not be 
detected accurately by PAEB systems. Toyota provided data to 
demonstrate that for S1b and S1e, a greater mannequin acceleration 
distance is needed to achieve a stable velocity. Honda recommended S1a-
d test conditions should have ``PTM Start Distance'' increased from 3.5 
m to 4.0 m and ``PTM Acceleration Distance'' increased from 0.5 m to 
1.0 m. For test condition S1e, the manufacturer suggested that ``PTM 
Start Distance'' should be increased from 5.5 m to 6.0 m and ``PTM 
Acceleration Distance'' should be increased from 1.0 m to 1.5 m. Honda 
and Auto Innovators mentioned that this has already been addressed in 
the Euro NCAP and JNCAP test procedures. Auto Innovators added that 
pedestrian mannequin motion tolerances can accumulate, resulting in the 
target's final location being farther away from its intended location. 
Accordingly, the group stated that the pedestrian mannequin motion 
tolerances should be reduced to ensure test repeatability, stating that 
if the highest test speed of 60 kph (37.3 mph) is adopted, tolerances 
should align with Euro NCAP's. IDIADA and Honda also recommended that 
NHTSA ensure the pedestrian and vehicle travel paths intersect at the 
intended location. Regarding false positive testing, GM requested 
clarity on deceleration distance in test condition S1f.
    Auto Innovators stated that controllability of the freeboard should 
be further investigated. For in-path test conditions S4a-c, Auto 
Innovators stated that NHTSA should ensure the pedestrian mannequin is 
properly mounted on the pole if the Agency intends to test conditions 
with the pedestrian mannequin facing both away from and towards the SV.
Subject Vehicle
    Regarding the movement of the SV, Honda suggested that the Agency 
use an accelerator/brake robot to increase the robustness of the test 
procedure. The automaker noted that changes like these would uphold 
NCAP's credibility and ensure well-defined safety performance 
information is gathered should the Agency collect self-reported data. 
Auto Innovators agreed, requesting that the SV be controlled by a 
steering robot.
    For PAEB testing in dark conditions, TRC commented that the ``aimed 
location'' of the SV's headlamps may need to be documented, further 
noting that IIHS currently records headlight aim for some of its work. 
Advocates stated the Agency should verify that the advanced 
headlighting system operates automatically. Additionally, Intel and ZF 
Group suggested the test should allow sufficient time for the 
headlighting systems to engage and switch to upper beams before the 
test begins (or at least 4 seconds TTC).

[[Page 96011]]

    Finally, SEMA stated that NHTSA should also test modified vehicles, 
defining modified as ``lifted and lowered.'' SEMA also requested that 
data, including mechanical and electronic tolerances, be published by 
the OEM so that modified vehicles' PAEB systems may achieve the same 
performance as a non-modified vehicle's performance. The group stated 
that such vehicle modifications are legal and should be accounted for.
Scenario and Test Condition Specifications
    Auto Innovators and GM stressed the importance of eliminating other 
artificial light sources that do not represent on-road conditions. The 
groups suggested the presence of such light may interfere with the 
intended operation of the PAEB system. If the artificial light sources 
cannot be removed, GM suggested that tests take place in the opposing 
direction, or, if this is not possible, vehicle high beams should be 
engaged to replicate the expected driving conditions. These commenters 
also requested alterations specific to certain test conditions. Auto 
Innovators stated the Agency should align the parked obstacle vehicle 
location in scenario S1d to the Euro NCAP condition, and GM requested 
clarity on definitions for pass/fail criteria for both false positive 
(S1f and S1g) conditions.
    Velodyne expressed concerns that the current test procedures do not 
include enough of the elements of real-world driving to effectively 
evaluate a vehicle's true PAEB performance. The company listed 
``shadows, unclear or unmarked lane lines or road edges, curved 
roadways, irregular route geometries, [. . .] irregularities in the 
roadway, cluttered or low contrast scenes, overhead objects, or 
irregular object shapes'' as potential confounding factors. Velodyne 
went on to state the shortcomings of cameras and radar in effectively 
informing PAEB systems, noting that adding more cameras and radar 
sensors will not be enough to address this issue. Velodyne suggested 
lidar will be necessary to address challenging real-world conditions 
such as those mentioned above.
Response to Comments and Agency Decisions
Publication of Draft Test Procedures
    NHTSA acknowledges the prior receipt of comments from Auto 
Innovators detailing feedback regarding the Agency's draft PAEB test 
procedures. The Agency has considered all comments received and has 
made changes to its PAEB test procedures accordingly. These revised 
PAEB test procedures are being published and docketed along with this 
final decision notice for use in NCAP testing.
Pedestrian Mannequin Target
    The Agency is adopting the pedestrian speeds proposed in the March 
2022 RFC notice. NHTSA acknowledges requests by respondents to make 
changes to the characteristics of the pedestrian mannequin target, 
including accounting for different pedestrian speeds based on walking 
or running speed. However, because the Agency must be mindful of the 
test burden created by adding additional test conditions, it is 
choosing to keep the proposed pedestrian speeds at this time. NHTSA 
notes the pedestrian mannequin speeds chosen for NCAP's PAEB test 
conditions align with those selected by Euro NCAP, and thus seem 
reasonable for inclusion in U.S. NCAP. Given the variations in test 
conditions adopted, including those for the pedestrian mannequin speed 
(i.e., walking, running, and stationary), the Agency expects that the 
prescribed pedestrian mannequin target speeds will mitigate crashes for 
pedestrians travelling faster or slower than the target speed. Real-
world pedestrian crashes that PAEB does not completely prevent may also 
be further mitigated by NCAP's forthcoming crashworthiness pedestrian 
protection testing program.\273\
---------------------------------------------------------------------------

    \273\ 88 FR 34366. The final decision notice for the NCAP 
crashworthiness pedestrian protection testing program is 
forthcoming.
---------------------------------------------------------------------------

    Further, NHTSA shares similar concerns as those expressed by 
commenters relating to pedestrian target acceleration, such as 
potential mannequin instability caused by inadequate starting and 
acceleration distances already observed and addressed by other global 
testing entities. Specifically, the Agency has observed that when the 
pedestrian mannequin begins to move, the mannequin tends to sway and 
oscillate for some time before gaining stability. Additionally, the 
Agency has found that sudden acceleration results in inconsistent 
pedestrian mannequin motion. Based on these concerns and observations, 
NHTSA will adopt amended starting and acceleration distances for its 
NCAP PAEB test procedures. For test conditions S1a-d, the pedestrian 
mannequin's starting distance will be 4.0  0.1 m (13.1 
 0.3 ft.) from the SV's intended travel path. For test 
condition S1e, the pedestrian mannequin's starting distance will be 6.0 
 0.1 m (19.7  0.3 ft.) from the intended travel 
path. For all conditions, the pedestrian mannequin's acceleration 
distance will be 1.5 m (4.9 ft.). These changes should increase 
repeatability and accuracy of PAEB system testing. Apart from the 
crossing path acceleration distance specification, these specifications 
also promote harmonization, as they are aligned with Euro NCAP's 
pedestrian mannequin starting and acceleration distances. NHTSA will 
also provide additional clarity on the deceleration distance for 
condition S1f if and when it chooses to adopt this test condition for 
NCAP.
    NHTSA will adopt a pedestrian mannequin target speed tolerance of 
0.4 kph ( 0.2 mph) for pedestrian mannequin motion 
tolerance. Despite commenter concern regarding tolerances being too 
wide and the pedestrian target's final location being inconsistent, 
particularly at higher speeds, the Agency's experience through its 
research testing to date is that this amount of tolerance is 
consistently achievable and provides a high-level of repeatability.
    Finally, because the Agency plans to adopt only the S4a and S4c 
test conditions, which both specify that the dummy face away from the 
vehicle instead of towards the vehicle as is required for the S4b 
condition, there is a decreased likelihood that the pedestrian 
mannequin will be improperly installed on the pole since there will be 
no need to switch the orientation of the pole during testing. Having 
said this, test laboratories will be expected to inspect their 
equipment prior to performing evaluations and to verify that the test 
setup is valid.
Subject Vehicle
    Repeatability of the SV's movements throughout the testing series 
was of concern to some commenters. A few suggested that either 
accelerator/brake (Honda) or steering (Auto Innovators) robots should 
be utilized. As with the AEB tests described earlier, steering and 
throttle requirements are specified; a test will be considered valid if 
these requirements are met. Thus, the Agency declines to require the 
use of throttle or steering robots at this time to conduct testing 
according to NCAP protocol. However, they may be used by laboratories 
or manufacturers if desired.
    NHTSA agrees with Intel and ZF Group's concern that the PAEB 
testing procedure for testing in dark conditions should allow time for 
any advanced lighting feature(s) that cannot be disabled to engage 
prior to the official start of the test. NHTSA will ensure that 
advanced lighting feature(s) engage automatically, if appropriate, and 
will

[[Page 96012]]

allow sufficient time prior to the vehicle's encounter with the 
pedestrian mannequin for the automatic engagement to occur. It is also 
reasonable to measure vehicles' headlamp aim angles and record these 
prior to testing, as TRC requested. However, the Agency will not alter 
the aim of vehicles' headlamps to align with manufacturer instructions 
prior to conducting PAEB tests. NHTSA asserts vehicle headlamps should 
be tested as received from the dealer for NCAP testing, since it is 
unlikely vehicle owners will adjust the aim of their headlamps prior to 
driving. Thus, maintaining factory settings should ensure more 
realistic testing.
    The Agency is not adopting the testing of modified vehicles at this 
time, as suggested by SEMA. NCAP's test methodology involves the 
evaluation of production-level vehicles available directly from the 
manufacturer, and any modified vehicle may not receive similar NCAP 
results, whether tested for crashworthiness or crash avoidance. Given 
the variety of legal modifications that may be completed in an 
aftermarket setting, it is not practicable to evaluate vehicles with 
modifications. Further, generating this information would be a 
significant burden to vehicle manufacturers.
Scenario and Test Condition Specifications
    NHTSA finds validity in the unspecified artificial light source 
concerns raised by GM and Auto Innovators. As the Agency seeks to 
replicate challenging real-world scenarios while also offering 
repeatable test conditions, it has decided that the test procedure for 
darkness PAEB testing will specify the ambient illumination at the test 
site must be no greater than 0.2 lux. This value approximates roadway 
lighting in dark conditions without direct overhead lighting with 
moonlight and low levels of indirect light from other sources, such as 
reflected light from buildings and signage. Additionally, an 
illumination level of 0.2 lux mirrors the level specified in the test 
procedures for the recently issued final rule for adaptive driving 
beams.\274\ This darkness level accounts for the effect ambient light 
has on AEB performance, particularly for camera-based systems, and 
should ensure robust performance of all AEB systems, regardless of 
sensor type. Also, NHTSA will not perform tests where the SV is driving 
toward the moon such that the horizontal angle between the moon and a 
vertical plane containing the centerline of the SV is less than 25 
degrees and the lunar elevation angle is less than 15 degrees. By 
incorporating these specifications, the Agency sees no need to allow 
manual high beam usage, as GM requested.
---------------------------------------------------------------------------

    \274\ 87 FR 9916.
---------------------------------------------------------------------------

    Auto Innovators suggested the Agency align the parked obstacle 
vehicle location in test condition S1d to the applicable specifications 
prescribed for Euro NCAP's comparable CPNCO test condition. The Agency 
confirms that NHTSA's S1d parked obstacle vehicle location aligns with 
Euro NCAP's CPNCO specification.
    In response to GM's request that the Agency clarify the pass/fail 
criteria for both false positive (S1f and S1g) test conditions, 
appropriate specification will be provided if and when the Agency 
chooses to adopt these test conditions for NCAP.
    Finally, while NHTSA acknowledges Velodyne's assertion that its 
current PAEB test procedures do not encompass all aspects of real-world 
driving, given the number of test conditions and variants included in 
NCAP's PAEB test matrix, the Agency concludes the published test 
procedures are sufficient to gauge overall PAEB system performance. 
NHTSA notes it must balance attempts to ensure system robustness with 
increased test burden. NHTSA may consider adopting additional test 
conditions or variants in the future encompassing one or more of the 
elements the commenter mentioned if real-world data identifies a 
significant need.
11. Adding Test Scenarios S2 and S3
    The Agency's 2019 PAEB test procedure does not include CAMP 
scenario S2 (vehicle turning right and a pedestrian crossing the road) 
or CAMP scenario S3 (vehicle turning left and a pedestrian crossing the 
road), both of which are defined earlier in this final notice. In 
response to the December 2015 RFC notice, several commenters stated 
that addressing these scenarios with available technology may generate 
a significant number of false positive detections. These false 
detections could have the unintended consequences of causing hazardous 
situations (e.g., unexpected sudden braking while turning in traffic) 
that could lead drivers to disable their PAEB systems or possibly lead 
to an increase in rear-end collisions. The commenters explained that 
the S2 and S3 test scenarios require more sophisticated algorithms as 
well as more robust test methodologies than those required for 
scenarios S1 and S4. However, ZF Group mentioned that ADAS sensors 
designed to meet Euro NCAP's Vulnerable Road Users test procedures 
would have increased fields-of-view, which should improve their 
effectiveness in turning scenarios. Other commenters stated that the 
articulating mannequins may not be representative of a real human for 
all sensing technologies in turning scenarios. Most commenters found it 
more appropriate to focus on the scenarios affording the most 
significant safety benefits first--S1 and S4, and stated that adding 
the S2 and S3 scenarios would be more practical when the technology 
matures. NHTSA committed to continuing PAEB system evaluations in its 
March 2022 RFC notice to determine the feasibility of including S2 or 
S3 scenarios as technological advancements are made.
    Earlier in this notice, the Agency stated it did not conduct the S2 
and S3 test scenarios as part of its PAEB characterization study and 
did not propose these test scenarios for inclusion in its current 
proposal to update NCAP. NHTSA agreed with the comments mentioned 
previously that most vehicles in the U.S. fleet are not currently 
equipped with sensing systems capable of detecting pedestrians while a 
vehicle is turning (i.e., those situations represented by S2 and S3 
test scenarios), as they do not have the necessary field-of-view. AAA 
conducted PAEB tests, including an S2 scenario where the vehicle is 
turning right with an adult pedestrian crossing.\275\ In AAA's testing, 
the PAEB systems for four tested model year 2019 vehicles did not react 
to the test targets during a testing scenario similar to NHTSA's S2 
scenario described above, resulting in all test vehicles colliding with 
the pedestrian mannequin target. These systems performed better in a 
scenario similar to NHTSA's S1 scenario, however. In that testing, the 
vehicles avoided a collision with the pedestrian mannequin target 40 
percent of the time at a 32.2 kph (20 mph) test speed and nearly all 
the time at a 48.3 kph (30 mph) test speed. Further, in its recent 
study on PAEB system effectiveness, IIHS found that while AEB with 
pedestrian detection was associated with significant reductions in 
pedestrian crash risk (approximately 27 percent) and pedestrian injury 
crash risk (approximately 30 percent), no evidence suggested that 
existing systems were effective while the PAEB-equipped vehicle was 
turning.\276\ Thus, it was

[[Page 96013]]

more beneficial to focus current efforts on performing PAEB testing at 
higher speeds and with various lighting conditions using the S1 and S4 
test scenarios. However, NHTSA's March 2022 RFC sought comment on an 
appropriate timeframe for including S2 and S3 scenarios in NCAP and 
requested information from vehicle manufacturers on any vehicle models 
designed to address, and ideally achieve crash avoidance, during 
conduct of the S2 and S3 scenarios to support Agency evaluation as part 
of a future program upgrade.
---------------------------------------------------------------------------

    \275\ American Automobile Association (2019, October), Automatic 
emergency braking with pedestrian detection, https://www.aaa.com/AAA/common/aar/files/Research-Report-Pedestrian-Detection.pdf.
    \276\ Cicchino, J. B. (2022, February), Effects of automatic 
emergency braking systems on pedestrian crash risk, Insurance 
Institute for Highway Safety, https://www.iihs.org/api/datastoredocument/bibliography/2243.
---------------------------------------------------------------------------

Summary of Comments
Include Turning Scenarios Now
    Commenters seeking the inclusion of turning scenarios into PAEB 
evaluations either immediately or as soon as possible (Bosch, Lidar 
Coalition, Aptiv, CAS, NTSB, MEMA, Adasky, Advocates, The League, ZF 
Group, IIHS, ASC, Intel, CR, AARP, Velodyne, Tesla, and a number of 
individual commenters), noted that including turning scenarios would 
align with Euro NCAP's test protocol and promote harmonization. NTSB 
did not provide a timeline for including turning PAEB scenarios in NCAP 
but stressed the importance of testing the upper limits of vehicle 
capabilities to drive innovation and advancement. Advocates and The 
League echoed NTSB's opinion, with Advocates noting that manufacturers 
are already able to meet expectations internationally. The League also 
questioned why NHTSA did not acknowledge or adopt the Euro NCAP CPTA 
protocol. Velodyne noted Euro NCAP's Roadmap for 2025, already 
highlights turning conditions as a priority for inclusion.
    Some commenters cited real-world injury data to support the prompt 
inclusion of turning scenarios, with Lidar Coalition reiterating nearly 
half of vehicle-to-pedestrian collisions occur at an intersection while 
the vehicle is turning. Although NHTSA's data has previously shown 
intersection crashes involving a crossing pedestrian and turning 
vehicle are generally of lower severity, Lidar Coalition noted vehicles 
have grown larger since this data analysis, a sentiment echoed by 
Velodyne. IIHS cited its 2022 study which found that at intersections, 
the odds that a crash that killed a crossing pedestrian involved a left 
turn by the vehicle versus no turn were about twice as high for SUVs, 
nearly three times as high for vans and minivans and nearly four times 
as high for pickups as they were for passenger cars.\277\ The group 
suggested that NHTSA begin evaluating S2 scenarios as a complementary 
approach to its consumer information program. Lidar Coalition and 
another individual acknowledged the same study and noted that a similar 
trend could be seen for crashes involving vehicles turning right. 
Therefore, Lidar Coalition requested that NHTSA perform a follow-up 
study to investigate more current severity trends with respect to 
pedestrians involved in turning pre-crash scenarios. NACTO also stated 
vehicles are three to four times more likely to fatally injure 
pedestrians while turning.
---------------------------------------------------------------------------

    \277\ Hu, W. and J.B. Cicchino. (2022, July), Relationship of 
pedestrian crash types and passenger vehicle types, Insurance 
Institute for Highway Safety.
---------------------------------------------------------------------------

    Commenters also noted the evolution of vehicle sensors and 
equipment. Specifically, Lidar Coalition stated that field-of-view 
limitations are of less concern when vehicles are equipped with a 
variety of sensors intended to monitor the sides of a vehicle, such as 
with BSW/BSI, and that consumers will expect the vehicle to be able to 
warn them of an impending crash with a pedestrian while turning because 
of ``rotational'' sensors monitoring their vehicles. ZF Group noted the 
field-of-view of current sensors has improved since prior consideration 
of the S2 and S3 scenarios, and vehicles would show improved 
performance at this time. Adasky stated that thermal cameras are also 
adequate to address S2 and S3 scenarios and have become more affordable 
and smaller in size. Adasky also discussed the capability of fusion 
sensors (thermal/RGB cameras/radar) and object detection software to 
perform well in these scenarios, particularly emphasizing the 
performance improvement that thermal cameras offer over RGB camera/
radar fusion systems. ASC, Intel, Velodyne, Aptiv, and others also 
noted that improved perception technology is currently available.
    Lidar Coalition and Velodyne stated that NHTSA should balance the 
risk of an increased numbers of false positives (and, therefore, rear-
end collisions) with the benefit to VRUs that may be afforded by 
including turning scenarios in PAEB evaluations. Both groups noted it 
is preferable for a driver to encounter a false positive activation and 
have time to react or override the intervention than to experience a 
false negative situation. Adasky recommended NHTSA evaluate false 
positive rates, as doing so may indicate system robustness and offer 
insight into possible areas of improvement.
    The Agency also received comments from NYC DOT/NYC DCAS, which 
expressed concern regarding consumer understanding of PAEB performance 
if S2 and S3 are not included in NHTSA's evaluations. The group stated 
the Agency needs to clearly convey that PAEB systems may not be as 
effective while turning as they are when the vehicle is driving 
straight.
    In relation to timing, some commenters mentioned that a phased 
approach may be appropriate. Aptiv advocated for a timeline similar to 
Euro NCAP's, with immediate inclusion of S2 and S3 when the pedestrian 
is oncoming with respect to the SV before the turn is initiated, and 
later inclusion of S2 and S3 scenarios with the pedestrian receding 
(possibly with two- or three-years lead-time between oncoming and 
receding). Aptiv justified this timing by noting oncoming pedestrian 
scenarios are less challenging to meet than receding pedestrian 
scenarios.
Wait To Include Turning Scenarios
    Some commenters recommended that NHTSA should wait to include S2 
and S3 pre-crash scenarios in NCAP. Specifically, BMW, GM, Honda, Auto 
Innovators, Toyota, FCA, and HATCI agreed that the S1 and S4 scenarios 
should be introduced first with turning pre-crash scenarios added at a 
later time. Toyota did not have a specific recommendation regarding a 
timeline for S2 and S3 scenario inclusion but did note the frequency of 
pedestrian crashes in which the striking vehicle was turning was very 
low (8 percent) compared to scenarios S1 and S4.\278\ HATCI also noted 
the higher relative frequency of S1 and S4 pre-crash scenarios in real-
world data. FCA stated there should be a demonstrated need and robust 
test procedure prior to the incorporation of any new technology 
assessment into NCAP. BMW suggested the latter half of this decade 
would be appropriate timing because of the possibility of increased 
false positive activations. Auto Innovators, FCA, and HATCI stated 
turning scenarios should be included in the Agency's future roadmap, 
with Auto Innovators specifically noting this item should be targeted 
for the mid- to long-term range. GM stated the S2 and S3 scenarios 
should be phased in later as part of a

[[Page 96014]]

mid-term update to allow time for planned system and sensor 
enhancements to enter the fleet. Honda suggested NHTSA evaluate the 
current vehicle fleet using the Euro NCAP CPTA protocol to determine 
whether current systems could meet requirements. The automaker did not 
give a timeframe for inclusion of S2 and S3 but noted S1 and S4 should 
be given priority.
---------------------------------------------------------------------------

    \278\ Carpenter, M.G., Moury, M.T., Skvarce, J.R., Struck, M. 
Zwicky, T.D., & Kiger, S.M. (2014, June), Objective tests for 
forward looking pedestrian crash avoidance/mitigation systems: Final 
report (Report No. DOT HS 812 040), Washington, DC: National Highway 
Traffic Safety Administration.
---------------------------------------------------------------------------

Other Suggestions
    Commenters also provided specific suggestions for the S2 and S3 
scenario test procedures in the event that NHTSA chose to adopt them 
with its final decision notice. Bosch recommended NHTSA amend the test 
procedure to have the SV perform a clothoid maneuver \279\ instead of 
the constant-radius maneuver currently specified. The group stated the 
clothoid path more closely resembles a real-world left turn maneuver 
and is more easily repeated in a test setting than is a constant-radius 
maneuver. ASC suggested adopting S2 with a 10 kph (6.2 mph) SV speed 
and conducting S3 at 10 kph (6.2 mph) and 20 kph (12.4 mph), since this 
would be in alignment with Euro NCAP's protocol.
---------------------------------------------------------------------------

    \279\ A clothoid is a curve whose curvature changes linearly 
with its curve length. It is often used as a transition curve in 
highway design.
---------------------------------------------------------------------------

    Commenters also expressed opinions on how to best convey PAEB 
system performance information for S2 and S3 pre-crash scenarios if 
these scenarios were adopted in NCAP. Rivian stated NHTSA should phase 
in levels of intervention by first giving credit to auditory warnings 
and then, at a later point in time, checking for speed reduction. Auto 
Innovators suggested that the Agency give credit for S2 and S3 
performance as a ``Recommended Technology'' rather than integrating 
these pre-crash scenarios into an overall rating. Conversely, Advocates 
stated it would like to see PAEB included in the rating itself rather 
than simply listed as a ``Recommended Technology,'' as it would allow 
consumers to differentiate between vehicle safety system performance.
Response to Comments and Agency Decisions
    While the Agency agrees with those commenters asserting there are 
inherent safety benefits in adopting S2 and S3 turning scenarios to 
assess PAEB systems, it will not incorporate these additional test 
scenarios as part of this NCAP upgrade.
    NHTSA acknowledges the many reasons commenters cited for adding 
turning scenarios to PAEB evaluations as soon as possible, including: 
harmonization with Euro NCAP's CPTA scenarios, anticipated real-world 
benefits and their potential to nullify the risk of a potential 
increase in false positives, the recent increase in vehicle size 
leading to more fatal crashes, recent sensor additions and 
advancements, and potential consumer confusion if such scenarios are 
omitted. Other commenters supported phasing in the turning PAEB test 
scenarios over time, with many agreeing with the Agency's proposal to 
adopt S1 and S4 scenarios as part of this upgrade to NCAP and S2 and S3 
scenarios as part of a future update. These commenters, many of which 
suggested that an appropriate timeline for S2 and S3 adoption would be 
approximately five to seven years, cited limited real-world benefits 
compared to those afforded by adoption of the S1 and S4 scenarios, and 
the need for test procedure development and Agency research. Aptiv also 
supported a phased approach to adoption of the S2 and S3 test scenarios 
but explained that certain turning scenarios could be added as part of 
the current program update (which also includes the adoption of S1 and 
S4) and others could be included two to three years later to allow time 
for PAEB systems to mature.
    Given the comments received, NHTSA reasons several actions must 
take place prior to the adoption of additional PAEB tests. 
Specifically, the Agency should first analyze recent crash data to 
further characterize scenarios for pedestrians involved in crashes with 
a turning vehicle. This analysis should allow the Agency to refine 
existing testing procedures to best address the safety need. Following 
this, NHTSA should conduct research testing to validate these test 
procedures and assess the capabilities of the current fleet. As part of 
the Agency's research effort, it will consider Bosch's suggestion to 
adopt a clothoid maneuver for the SV in lieu of a constant-radius 
maneuver to improve test repeatability, along with ASC's recommendation 
to align test speeds to those prescribed by Euro NCAP. In the event the 
Agency develops a proposal to add the S2 and S3 PAEB tests to NCAP in 
the future, as many respondents suggested, the Agency will also 
consider the comments received from Rivian, Auto Innovators, and 
Advocates pertaining to performance requirements and incorporating the 
associated test results for the turning scenarios for ratings purposes. 
In the meantime, NHTSA will communicate on its website test specifics 
for the PAEB scenarios the Agency is adopting so the public may 
understand NCAP's assessments are limited to only those situations 
reflected by the tests conducted and do not encompass all situations 
involving pedestrians that a driver may encounter, as NYC DOT/NYC DCAS 
requested.
12. Future Safety Areas for Pedestrian Protection
    NHTSA requested comments on other safety areas that should be 
considered as part of a pedestrian protection NCAP strategy for this 
program update or the future. NHTSA received many comments on this 
topic, summarized below.
Summary of Comments
Pedestrian Crashworthiness
    An overwhelming number of commenters responded in favor of 
incorporating a crashworthiness pedestrian protection component to the 
NCAP ratings. Commenters expressed concerns about the increasing size 
(both in height and weight) of vehicles in the U.S., noting that 
consumers often purchase larger vehicles to protect their own families 
while inadvertently placing VRUs at a disadvantage. Those in favor of a 
pedestrian crashworthiness component reasoned that its incorporation 
would help balance the risk between those inside and outside of the 
vehicle. Many commenters also mentioned that ADAS technologies will not 
be effective in every scenario and requested that NHTSA take a multi-
pronged approach in addressing pedestrian injuries and fatalities. 
These individuals suggested manufacturers design their vehicles to be 
more pedestrian-friendly, rather than relying on technology that may 
not be completely effective to avoid the crash. Many commenters noted 
Euro NCAP currently performs this testing.\280\ \281\
---------------------------------------------------------------------------

    \280\ European New Car Assessment Programme (Euro NCAP) 
(December 2023), Vulnerable Road User Testing Protocol, Version 9.1.
    \281\ In Euro NCAP's VRU protection protocol, head impactors and 
leg impactors are used to evaluate a pedestrian's injury risk after 
an impact with the test vehicle.
---------------------------------------------------------------------------

    The League specifically requested NHTSA evaluate vehicles for 
crashworthiness protection for cyclists, those in wheelchairs, and 
other VRUs sharing the roadway with motor vehicles. It stated that if 
this evaluation cannot be included in NCAP, it should at least be 
undertaken as research to allow all parties (consumers, researchers, 
and vehicle manufacturers) to better understand how vehicle design 
influences injury in these populations.

[[Page 96015]]

Direct Visibility
    Commenters also expressed concerns relating to direct driver 
visibility, with many stating that ADAS technologies involving cameras 
and sensors should not be the first solution to increase the field of 
view of a driver. Instead, they preferred manufacturers consider 
vehicle designs which eliminate or greatly reduce blind zones at early 
stages of development. Commenters noted that minimized blind zones may 
improve a driver's ability to see and respond to VRUs who use assisted 
mobility devices, such as wheelchairs, walkers, or scooters, and may 
already be closer to the ground. One individual also suggested that 
visibility of a pedestrian or other VRU after an initial PAEB 
intervention has taken place should be accounted for, allowing the 
driver to physically see why the vehicle intervened and take 
appropriate actions.
Pedestrian Mannequin Target
    Many commenters requested changes to the pedestrian mannequin 
target and/or additional targets to represent a wider variety of VRUs 
more closely. Of particular concern was the ability of PAEB systems to 
accurately detect people of color. NACTO cited a 2019 study from the 
Georgia Institute of Technology \282\ that demonstrated automated 
vehicles cannot detect darker skin as well as lighter skin. The group 
further stated that ``people of color, particularly Black and 
Indigenous people, are disproportionately killed while walking and are 
more likely to live in communities with unsafe, inadequate 
infrastructure for walking and biking.'' NSC added that although 
pedestrian deaths represent about 14% of all traffic deaths among 
white, non-Hispanics, they represent more than 20% of pedestrian 
fatalities among Hispanics, Black non-Hispanics, and Native Americans. 
NSC further noted that, compared to white non-Hispanics, the pedestrian 
fatality rate for Native Americans is almost four times as high, and 
the pedestrian fatality rate for the Black community is nearly twice as 
high. These sentiments were detailed by safety advocates, local 
government organizations, and individuals alike.
---------------------------------------------------------------------------

    \282\ https://arxiv.org/pdf/1902.11097.pdf.
---------------------------------------------------------------------------

    Commenters also expressed concerns with the height of the 
pedestrian mannequin target, particularly for shorter individuals, 
including children. An individual commenter stated that children are 
vulnerable to pedestrian impacts not only because of their size 
relative to a modern vehicle's size, but also because of the behavioral 
differences between adults and children. Specifically, the commenter 
noted that children are less likely to use the same judgment around 
vehicles as adults, citing evidence to support this claim.\283\ NSC 
stated that, in 2017, one in every five children killed in a crash were 
pedestrians. Several individuals and one group (Bikemore) stated the 
pedestrian mannequin should be representative of a 2-year-old child. 
MEMA noted there are currently 2-year-old and 7-year-old pedestrian 
mannequins available, adding they should also be included in a future 
NCAP upgrade. Auto Innovators supported the use of a 7-year-old child 
target in the future. Uhnder stated child targets should be used in all 
testing, noting that all VRUs should be equally represented. ASC also 
stated all VRUs should be represented equally, adding that NHTSA should 
consider using them beyond scenario S1d.
---------------------------------------------------------------------------

    \283\ Elizabeth E. O'Neal et al., Changes in Perception-Action 
Tuning Over Long Time Scales: How Children and Adults Perceive and 
Act on Dynamic Affordances When Crossing Roads, 44 JOURNAL OF 
EXPERIMENTAL PSYCHOLOGY: HUMAN PERCEPTION AND PERFORMANCE 18 (2018).
---------------------------------------------------------------------------

    Commenters also noted several other areas of potential interest for 
characteristics of the pedestrian target, including: gender, clothing 
type and color, carried or pushed objects (such as a stroller), and the 
use of assistive mobility devices like wheelchairs and scooters. For 
example, AARP suggested that PAEB systems should be able to recognize 
pedestrians carrying shopping bags or walking a bicycle across a road. 
Advocates cited the NTSB's findings that a 2018 crash involving a 
vehicle equipped with ADAS technologies occurred because the vehicle 
did not properly identify the pedestrian walking her bicycle across the 
road.\284\ One commenter who uses a wheelchair stated those using 
assistive mobility devices like wheelchairs are already more difficult 
to see while traveling because their head is lower to the ground, 
including sometimes below the hoods of vehicles. Likewise, one 
individual commenter noted wheelchair users are 36 percent more likely 
to be killed as pedestrians than the overall population. Uhnder and 
another individual stated that darker clothing is more difficult for 
the human eye to distinguish from surroundings in the dark, 
particularly for pedestrians traveling at night. It would be imperative 
for a PAEB system to recognize and respond to a pedestrian wearing such 
clothing.
---------------------------------------------------------------------------

    \284\ https://www.ntsb.gov/investigations/accidentreports/reports/har1903.pdf.
---------------------------------------------------------------------------

    Finally, Auto Innovators and GM stressed the need for field 
pedestrian crash data to support any additional safety areas addressed 
by NCAP.
Inclement/Challenging Weather
    Many comments addressed PAEB performance in poor weather conditions 
and in a variety of environments. As discussed in previous sections of 
this notice, many respondents expressed concerns over performance 
degradation in rain, snow, and fog. Walk and Roll Bellingham stated 
that a system that will not work in these conditions would not be 
useful to them, as inclement weather is common.
    One individual commented that many crashes occur during dawn and 
dusk, which are mid-level lighting conditions. The commenter stated 
this may be due to sun glare or to more individuals traveling at these 
times of day, noting it should be a targeted scenario due to frequency 
of occurrence.
Other Scenarios To Consider
    Commenters also suggested other PAEB scenarios and variations the 
Agency should consider, with Uhnder, ASC, and one individual 
recommending the addition of a test simulating a pedestrian crossing 
the road with another vehicle approaching in oncoming traffic, both in 
daylight and dark lighting conditions. Uhnder also suggested including 
a test with a pedestrian crossing under a bridge or walkway. Uhnder 
stated that these scenarios, which had once been difficult for the SV 
to pass because sensors could not properly resolve the pedestrian, are 
now less challenging for modern sensors. Vayyar recommended including a 
parking lot scenario in which a vehicle enters and exits a parking 
space. CAS noted that highway signage, crosswalk painting, and 
construction should be accounted for in NHTSA's testing.
    One individual pointed out there is currently no provision to 
mitigate a crash with a pedestrian that may be lying in the road, and 
that such a case might apply to a pedestrian that has already been 
struck.
    TRC, AARP, and one individual pointed out this proposal does not 
address backovers. TRC and the individual commenter noted Euro NCAP has 
developed and approved a protocol for reverse pedestrian braking. 
Accordingly, TRC asserted the Agency could readily adopt this test as 
part of its PAEB test procedures. Similarly, the individual commenter 
expressed that it was unacceptable NHTSA did not plan

[[Page 96016]]

to include reverse and turning scenarios until the 2025-2031 timeframe. 
AARP suggested that including a reverse pedestrian test will improve 
PAEB technology more rapidly.
    Finally, Vision Zero Network and NACTO expressed concerns with a 
PAEB system's ability to distinguish pedestrians traveling in a crowd.
Vehicle to Everything (V2X)
    Several commenters expressed that V2X technology could help drivers 
and VRUs avoid potential hazards, especially as vehicles increasingly 
share roads with pedestrians, bicyclists, etc. 5G Automotive 
Association noted that V2X technology developed under the 3rd 
Generation Partnership Project already supports vehicle-to-pedestrian 
communications. Two additional commenters stated V2X technology could 
be used specifically to help address the nighttime pedestrian crash 
problem. ASC and one individual commenter stated that vehicles could 
assess nearby smartphone location data to locate and track VRUs. ASC 
suggested NHTSA perform testing with location data enabled smartphones 
attached to the pedestrian mannequin for vehicles equipped with this 
technology.
Other Comments
    ZF Group commented that pedal misapplication is a concern and that 
as the country ages, incidents could increase. Additionally, the group 
noted JNCAP has developed a protocol to evaluate acceleration 
suppression technologies to mitigate the risk and suggested NHTSA 
investigate this further.
    Another individual stated NHTSA should require vehicles to make 
sound at low speeds to warn pedestrians that a vehicle is in motion 
nearby.
Response to Comments and Agency Decisions
    Many commenters stated the Agency should pursue multiple paths 
beyond those specifically proposed in the March 2022 notice to fully 
mitigate pedestrian crashes. NHTSA's response to these comments 
follows.
Pedestrian Crashworthiness
    Many commenters expressed that vehicle manufacturers should take 
pedestrian crashworthiness into account when designing vehicles. As 
noted previously, NHTSA intends to develop a pedestrian crashworthiness 
FMVSS to address pedestrian head impacts to vehicle hoods and has also 
proposed a separate testing program for NCAP.\285\ \286\ Comments will 
be considered independently in the context of those actions. The Agency 
hopes that, if implemented, these efforts may help to address the need 
to balance risk to occupants in the vehicle with those outside of the 
vehicle.
---------------------------------------------------------------------------

    \285\ https://www.reginfo.gov, RIN 2127-AK98.
    \286\ 88 FR 34366 (May 26, 2023).
---------------------------------------------------------------------------

Direct Visibility
    The Agency is looking into this further to determine the best 
approach to address these issues and has included driver visibility in 
the 10-year roadmap for consideration in future NCAP updates.
Pedestrian Mannequin Target
    NHTSA notes the proposed 4activePA adult and child articulated 
mannequins represent a 50th percentile male adult and a 7-year-old 
child. Both pedestrian mannequin targets have the same clothing and 
skin/hair color. Many commenters suggested alternative pedestrian 
targets, noting that a variety of VRUs should be accounted for. This 
included people of color; VRUs of differing heights, ages, and clothing 
styles; those who use assistive mobility devices; or those carrying 
objects which may impede proper detection.
    Because the Agency is not currently aware of alternative pedestrian 
targets proven to be reliable, including those representing a toddler-
aged child, those using mobility aids, or those with alternative 
clothing, the proposed 4active targets will be adopted for this NCAP 
update. As noted previously, these are the pedestrian targets adopted 
for use by Euro NCAP. However, NHTSA is currently conducting research 
to evaluate vehicle response to various pedestrian characteristics, 
such as clothing color and type. This research will inform next steps 
for the Agency.
    Regarding children in particular, the Agency notes that, while 
there are likely behavioral differences between adults and children, as 
one commenter claimed, crash data show that child pedestrian 
involvement is relatively low. In 2021, less than one-sixth (15 
percent) of children aged 14 and younger killed in traffic crashes were 
pedestrians, and the age group with the fewest pedestrian fatalities 
was ages five to nine years, followed by the less than five-year-old 
age group.\287\ That said, for this NCAP update, the Agency will 
utilize the seven-year-old 4activePA mannequin for S1d. Use of this 
pedestrian target in at least one condition should ensure that vehicle 
manufacturers account for smaller pedestrians in their PAEB system 
designs while still targeting the largest population of pedestrians for 
the majority of adopted conditions. The Agency may revisit this 
decision in the future if additional mannequins are found to be 
reliable during testing, sensing technology improves, and/or the real-
world crash problem changes.
---------------------------------------------------------------------------

    \287\ National Center for Statistics and Analysis. (2023, June), 
Pedestrians. (Traffic Safety Facts, 2021 Data. Report No. DOT HS 813 
458), Washington, DC: National Highway Traffic Safety 
Administration.
---------------------------------------------------------------------------

Inclement/Challenging Weather Conditions
    NHTSA has decided that all NCAP PAEB testing will occur in dry, 
clear conditions free of fog, smoke, ash, or other airborne particulate 
matter with the minimum visibility range stated. Doing so should ensure 
that each vehicle is evaluated under the same circumstances and 
maintain a reasonable test burden.
    NHTSA acknowledges that pedestrian crashes occur in various weather 
conditions. According to Volpe data from 2011-2015, approximately 10 
percent of fatal pedestrian crashes and 13 percent of injurious 
pedestrian crashes occurred during adverse weather annually.\288\ PAEB 
systems should be functional in a variety of weather conditions. This 
especially holds true for areas of the country subject to frequent 
inclement weather.
---------------------------------------------------------------------------

    \288\ Swanson, E., Foderaro, F., Yanagisawa, M., Najm, W.G., & 
Azeredo, P. (2019, August), Statistics of light-vehicle pre-crash 
scenarios based on 2011-2015 national crash data (Report No. DOT HS 
812 745), Washington, DC: National Highway Traffic Safety 
Administration.
---------------------------------------------------------------------------

    However, for an NCAP testing program to be useful to consumers, 
repeatability and reproducibility of test results is imperative. The 
presence of precipitation could influence the outcome of the tests, as 
pavement covered in precipitation may have a lower coefficient of 
friction than dry pavement and falling precipitation may interfere with 
sensing systems such that vehicles are not independently subjected to 
the same conditions. The same logic applies to visibility at the test 
site. A current industry standard specifies the horizontal visibility 
at ground level must be greater than 1 km (0.62 miles), a standard also 
adopted by Euro NCAP for its AEB/LSS protocol.\289\ Thus, NHTSA will 
conduct all NCAP PAEB tests in dry, clear conditions free of fog, 
smoke, ash, or other airborne particulate matter with the minimum 
visibility range stated. However, similar to that which the Agency 
indicated for

[[Page 96017]]

turning scenarios S2 and S3, NHTSA may communicate on its website 
possible system limitations pertaining to environmental conditions not 
assessed by NCAP to lessen consumer confusion relating to expectations 
for system functionality. Further, notwithstanding the adopted test 
specificity, NHTSA encourages manufacturers to continue working toward 
delivering PAEB systems that are robust and that function in as many 
real-world environments as possible.
---------------------------------------------------------------------------

    \289\ European New Car Assessment Programme (Euro NCAP) 
(December 2023), Test Protocol--AEB/LSS VRU systems, Version 4.5.
---------------------------------------------------------------------------

Other Scenarios To Consider
    NHTSA acknowledges that real-world driving involves a variety of 
situations. Commenters noted that the proposed testing conditions do 
not address such scenarios as: parking lots; cases where an oncoming 
vehicle is also present; situations where a pedestrian is crossing 
under a structure such as a bridge; backover incidents; or other 
surroundings such as signs, roadway markings, and other visual clutter, 
such as that found in construction zones.
    The Agency agrees that each of these situations represents a 
possible real-world case in which PAEB is expected to function. 
However, it would not be possible to test every permutation, as the 
resources required for this endeavor would make such a testing program 
prohibitive. As mentioned in previous sections, NHTSA plans to monitor 
real-world cases and has the authority to investigate situations which 
prove increasingly problematic.
    Several commenters expressed concern that a specific mitigation 
plan for backover pedestrian crashes was not included in the Agency's 
March 2022 proposal, beyond inclusion in a short-term roadmap. At that 
time, NHTSA referred to data which showed NHTSA backing data from 2021 
in-traffic pedestrian crashes shows that most pedestrian fatalities 
where the first harmful event was a collision with the vehicle are a 
result of initial contact with the front of the vehicle. As detailed in 
the March 2022 RFC notice, more time is required for NHTSA to review 
real-world data and the effects of FMVSS No. 111, ``Rear visibility.'' 
This information will also help inform changes to the rear automatic 
braking (RAB) test procedure, which remains under further development. 
Thus, NHTSA concludes that while Euro NCAP has developed an RAB 
protocol for use in its testing, it would be premature for the Agency 
to incorporate RAB as a U.S. NCAP ADAS technology at this time.
    NHTSA will also not perform PAEB testing for a lying, stationary 
pedestrian at this time. These cases are likely rare and would not 
represent a large portion of the pedestrian crash problem. Further, 
there is not a test procedure developed at this time to address such a 
scenario. Similarly, there is not a test procedure currently developed 
to assess a PAEB system's response to multiple pedestrians in a group, 
so this scenario will also not be incorporated into NCAP testing at 
this time.
Vehicle to Everything (V2X)
    NHTSA also received a suggestion to incorporate V2X support into 
its PAEB test procedures for dark lighting conditions. This would allow 
vehicles to utilize smartphone location data to locate the pedestrian 
target and map its movement. As a result, V2X technology could help to 
mitigate cases in which a VRU is not visible due to obstruction, lack 
of lighting, or other environmental factors. However, because the 
Agency has not conducted testing of a smartphone-enabled test target, 
it would be premature to incorporate this additional specification into 
PAEB testing at this time. Further, DOT research has not yet determined 
whether cellular-based V2X would be able to support safety-critical 
crash avoidance technologies, although it may have benefits for 
weather, traffic, and infrastructure-related alerts. NHTSA may consider 
the inclusion of this technology in NCAP in the future.
Other Comments Related to Pedestrian Safety
    As part of NHTSA's AEB research to further assess the rear-end 
safety problem, characterize current vehicles, and identify potential 
countermeasures, the Agency will study pedal misapplication. AEB/PAEB 
test procedure modifications it deems necessary as a result of that 
effort may be adopted as part of subsequent updates to NCAP.
    NHTSA notes all electric and hybrid vehicles manufactured on or 
after March 1, 2021, are required to produce a sound at low speeds per 
FMVSS No. 141, ``Minimum sound requirements for hybrid and electric 
vehicles.'' This standard should address concerns related to quiet 
vehicles and pedestrian crash risk.
13. Acceptable Timeframe To Add Bicyclist Testing and Test Procedures 
Other Than Euro NCAP's To Address Bicyclist Crashes
    In its March 2022 RFC notice, the Agency committed to conducting 
additional research to address injuries and fatalities for other VRUs, 
specifically bicyclists and motorcyclists. NHTSA's current PAEB test 
procedure does not include a specific bicyclist component, although 
PAEB systems capable of detecting bicyclists may exist. The rising 
number of bicyclists killed on U.S. roads \290\ prompted the Agency to 
study and determine the viability of Euro NCAP's AEB bicyclist 
tests.\291\
---------------------------------------------------------------------------

    \290\ National Center for Statistics and Analysis (2019, June), 
Bicyclists and other cyclists: 2017 data (Traffic Safety Facts. 
Report No. DOT HS 812 765), Washington, DC: National Highway Traffic 
Safety Administration.
    \291\ European New Car Assessment Programme (Euro NCAP) 
(December 2023), Test Protocol--AEB/LSS VRU systems, Version 4.5.
---------------------------------------------------------------------------

    Acknowledging the current state of bicyclist PAEB testing in the 
U.S., NHTSA requested comments detailing when it would be acceptable to 
add bicyclist PAEB testing to its suite of ADAS tests, and whether 
there are other test procedures available beyond Euro NCAP's to 
evaluate. The Agency also requested information from vehicle 
manufacturers on any currently available models with the capability to 
validate the bicyclist target and test procedures used by Euro NCAP to 
support evaluation for a future NCAP program upgrade.
Summary of Comments
    An overwhelming majority of commenters who addressed the issue 
urged NHTSA to move forward with a bicyclist component as soon as 
possible. Somerville Bicycle Safety noted that according to NSC, 
bicyclist fatalities increased 44 percent from 2011 to 2020.\292\ The 
League stated that other NHTSA FARS data shows that in 2020, 276 
bicyclists were killed by the grouped crash type, ``motorist overtaking 
bicyclist,'' which was more than three times the number of those killed 
in the next crash type, ``parallel paths--other circumstances,'' and 
noted that these crash types could be addressed by AEB.
---------------------------------------------------------------------------

    \292\ https://injuryfacts.nsc.org/home-and-community/safety-topics/bicycle-deaths/.
---------------------------------------------------------------------------

    Vision Zero Network, the League, and Bike Cleveland noted that 
rising cyclist deaths are cited as a targeted issue in USDOT's National 
Roadway Safety Strategy (NRSS). Further, the BIL's requirement to 
consider benefits of harmonization with domestic and international 
ratings systems was cited by PeopleForBikes and Ride New Orleans. 
Advocates also noted there is an increased interest from the U.S. DOT 
and other transportation organizations in the use of bicycles in urban 
transportation programs to travel to school and work.
    Respondents also cited the availability of a bicyclist target and 
Euro

[[Page 96018]]

NCAP's protocol in support of NHTSA's adoption of a bicyclist component 
for PAEB. Intel, Vision Zero Network, Safe Roads Alliance, Aptiv, 
Somerville Bicycle Safety, PeopleForBikes, AARP, The League, NACTO, 
Ride New Orleans, Advocates, CAS, ITS America, Bike Cleveland, KAC, 
ASC, FSS, and Vayyar all referred to Euro NCAP's readily available 
protocol as a reason to move urgently. Intel specifically noted that 
bicyclist AEB should be included in the 2023-2024 timeframe of NCAP's 
roadmap because of this readily available and updated protocol. Lidar 
Coalition noted that NHTSA's plan to not include bicyclist AEB until a 
future NCAP upgrade appears out of step with the Agency's stated goals 
to address areas of substantial safety need and to harmonize with Euro 
NCAP wherever possible. The League noted inconsistencies in NHTSA's 
justifications for including other ADAS technologies for this NCAP 
upgrade, including BSI and CIB, to encourage proliferation and 
development of capabilities in the vehicle fleet, while not also 
including bicyclist AEB. Other commenters stated that NHTSA, and 
therefore the U.S., will lag behind European countries by a decade 
should NHTSA decide to delay inclusion of bicyclist detection as shown 
in the draft NCAP roadmap. Several commenters stated that Australasian 
NCAP, JNCAP, and IIHS, in addition to Euro NCAP, already take 
bicyclists into account in their PAEB/AEB testing.
    The NTSB submitted a comment referring to its 2019 recommendation 
that NHTSA incorporate vehicle-to-bicyclist crash avoidance 
capabilities in NCAP as a mechanism to incentivize incorporation of the 
technology in vehicles.\293\ The accompanying study showed that vehicle 
ADAS could reduce the frequency of bicyclist crashes.
---------------------------------------------------------------------------

    \293\ NTSB Safety Recommendation H-19-36.
---------------------------------------------------------------------------

    Some commenters stated that the Agency should wait until a future 
NCAP upgrade to include bicyclist detection in PAEB/AEB testing. These 
included Auto Innovators, HMNA, GM, Honda, and HATCI. GM and Auto 
Innovators stated the Agency should take more time for NCAP to evolve 
and should adopt Euro NCAP procedures when NHTSA eventually adopts 
bicyclist detection protocols. Honda acknowledged that bicyclist 
detection is an important feature that should be included but suggested 
that it be included at a future time, as Scenarios S1 and S4 should be 
prioritized. HATCI suggested that if NHTSA plans to harmonize with Euro 
NCAP, NHTSA could move forward as part of a future upgrade, but if the 
Agency is going to make changes to the protocol, then HATCI recommended 
that NHTSA publish the amended test procedure for review and comment. 
Finally, DRI mentioned that, in its experience, the current bicyclist 
targets available on the market lack the durability for continuous 
testing during which impacts may occur.
    Several commenters stated more research would be useful to inform 
decisions regarding appropriate test scenarios and conditions. Auto 
Innovators, GM, Tesla, FCA, and the League suggested that NHTSA review 
U.S. crash data to determine any necessary adaptations to Euro NCAP 
test scenarios for the U.S. market. The groups suggested the Agency 
should take into consideration variables such as specific crash 
scenarios commonly seen in fatal crashes, SV and bicyclist speeds, and 
road features and markings specific to the U.S. market. The League also 
stated that door opening crashes, in which a vehicle occupant opens 
their door into the path of an approaching bicyclist, are likely 
underrepresented in FARS data, as other sources estimate that 7 percent 
to 20 percent of all cyclist crashes involve this crash type. Uhnder 
also supported continued studies to determine which scenarios are most 
likely to be found on U.S. roadways. Uhnder and ASC also suggested that 
NHTSA undertake a characterization study of bicyclist targets \294\ to 
include radar cross section (RCS), like the study completed for 
pedestrian targets, prior to incorporation of a bicyclist 
component.\295\
---------------------------------------------------------------------------

    \294\ Including ISO19206-2, ISO19206-4, and ISO19206-5 (under 
development) targets.
    \295\ Albrecht, H. (2015, November 5). ``Pedestrian Test 
Mannequins Objective Criteria for Evaluating Repeatability and 
Accuracy of PCAM Systems.'' SAE Active Safety Symposium. Plymouth, 
MI.
---------------------------------------------------------------------------

    The League stated when bicyclist AEB testing begins, it should be 
conducted in both daylight and dark lighting conditions. The group 
stated it is relevant to include these test conditions because NHTSA 
FARS data showed between 2016 and 2020, about 50 percent of bicyclist 
fatalities occurred during dark lighting conditions.\296\
---------------------------------------------------------------------------

    \296\ National Highway Traffic Safety Administration. Fatality 
and Injury Reporting System Tool (FIRST), Version 6. Fatality 
Analysis Reporting System (FARS): 2016-2020 Final File.
---------------------------------------------------------------------------

    In addition to bicycles, commenters stated other signatures, such 
as scooters and wheelchairs, should also be detected by vehicle AEB 
systems. MIC/MSF specifically recommended NHTSA also ensure the 
inclusion of motorcyclist tests. One individual stressed the importance 
of bicycle infrastructure, requesting safer spaces for cyclists to 
travel on the roadway.
Response to Comments and Agency Decisions
    NHTSA recognizes many of the commenters supported the inclusion of 
bicyclist testing in NCAP and wanted the Agency to take such action 
immediately. Two of the main reasons cited for this inclusion were the 
need to fulfill initiatives established in the NRSS and BIL mandates, 
as well as incentivizing the proliferation and development of system 
capabilities in the vehicle fleet. These commenters referenced several 
existing test procedures and test targets that could be utilized to 
assess system performance to mitigate light vehicle crashes with 
bicyclists.
    However, the Agency agrees with those commenters who suggested it 
should conduct additional research prior to adoption of a bicyclist 
component into NCAP. Existing test procedures, such as that in Euro 
NCAP, for evaluating crash avoidance technologies for bicyclist and 
motorcyclist protection need further evaluation for their 
effectiveness, objectivity, and suitability for vehicles sold in the 
U.S. Additional assessment is also needed on the durability and 
suitability of the targets used in the tests.
    NHTSA has expedited its research on AEB for other VRUs, namely 
bicyclists and motorcyclists. Initial research has been performed on 
surrogate bicycle and motorcycle targets for testing and global test 
procedures to evaluate their effectiveness and suitability for use in 
performance tests. Further crash data analysis will be performed to 
better characterize the critical safety scenarios that account for 
bicycle and motorcycle injuries and fatalities. Collectively, this 
information will lead to test procedures that can be used to assess 
safety performance of vehicles sold in the U.S. This research effort is 
expected to be completed in 2025. As noted in the mid-term updates to 
NCAP in the NCAP roadmap finalized in this notice, NHTSA has included 
evaluation of AEB for mitigating crashes with bicyclists and 
motorcyclists starting with model year 2028 vehicles.

E. Summary of Adopted Tests for Pedestrian Automatic Emergency Braking

    Tabular summaries of the adopted test conditions and variants for 
PAEB are provided in Tables 19 and 20.

[[Page 96019]]



                                            Table 19--Adopted NCAP PAEB Daylight Test Conditions and Variants
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                                                                              Test speeds (kph (mph))
  Test condition          Size            Movement         Path origin      Overlap (%)      Obstruction       Test No.  -------------------------------
                                       classification                                                                           SV          Pedestrian
--------------------------------------------------------------------------------------------------------------------------------------------------------
S4c...............  Adult (Facing     Walk............  Right...........              25  No...............            1        10 (6.2)        5 (3.1).
                     Away).                                                                                            2       20 (12.4)        5 (3.1).
                                                                                                                       3       30 (18.6)        5 (3.1).
                                                                                                                       4       40 (24.9)        5 (3.1).
                                                                                                                       5       50 (31.1)        5 (3.1).
                                                                                                                       6       60 (37.3)        5 (3.1).
S4a...............  Adult (Facing     Stationary......  Right...........              25  No...............            7        10 (6.2)              0.
                     Away).                                                                                            8       20 (12.4)              0.
                                                                                                                       9       30 (18.6)              0.
                                                                                                                      10       40 (24.9)              0.
                                                                                                                      11       50 (31.1)              0.
                                                                                                                      12       60 (37.3)              0.
S1b...............  Adult...........  Walk............  Right...........              50  No...............           13        10 (6.2)        5 (3.1).
                                                                                                                      14       20 (12.4)        5 (3.1).
                                                                                                                      15       30 (18.6)        5 (3.1).
                                                                                                                      16       40 (24.9)        5 (3.1).
                                                                                                                      17       50 (31.1)        5 (3.1).
                                                                                                                      18       60 (37.3)        5 (3.1).
S1a...............  Adult...........  Walk............  Right...........              25  No...............           19        10 (6.2)        5 (3.1).
                                                                                                                      20       20 (12.4)        5 (3.1).
                                                                                                                      21       30 (18.6)        5 (3.1).
                                                                                                                      22       40 (24.9)        5 (3.1).
                                                                                                                      23       50 (31.1)        5 (3.1).
                                                                                                                      24       60 (37.3)        5 (3.1).
S1e...............  Adult...........  Run.............  Left............              50  No...............           25        10 (6.2)        8 (5.0).
                                                                                                                      26       20 (12.4)        8 (5.0).
                                                                                                                      27       30 (18.6)        8 (5.0).
                                                                                                                      28       40 (24.9)        8 (5.0).
                                                                                                                      29       50 (31.1)        8 (5.0).
                                                                                                                      30       60 (37.3)        8 (5.0).
S1d...............  Child...........  Run.............  Right...........              50  Yes..............           31        10 (6.2)        5 (3.1).
                                                                                                                      32       20 (12.4)        5 (3.1).
                                                                                                                      33       30 (18.6)        5 (3.1).
                                                                                                                      34       40 (24.9)        5 (3.1).
                                                                                                                      35       50 (31.1)        5 (3.1).
                                                                                                                      36       60 (37.3)        5 (3.1).
--------------------------------------------------------------------------------------------------------------------------------------------------------


                                            Table 20--Adopted NCAP PAEB Darkness Test Conditions and Variants
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                                                                              Test speeds (kph (mph))
  Test condition          Size            Movement         Path origin      Overlap (%)      Obstruction       Test No.  -------------------------------
                                       classification                                                                           SV          Pedestrian
--------------------------------------------------------------------------------------------------------------------------------------------------------
S4c...............  Adult (Facing     Walk............  Right...........              25  No...............            1        10 (6.2)        5 (3.1).
                     Away).                                                                                            2       20 (12.4)        5 (3.1).
                                                                                                                       3       30 (18.6)        5 (3.1).
                                                                                                                       4       40 (24.9)        5 (3.1).
                                                                                                                       5       50 (31.1)        5 (3.1).
                                                                                                                       6       60 (37.3)        5 (3.1).
S4a...............  Adult (Facing     Stationary......  Right...........              25  No...............            7        10 (6.2)              0.
                     Away).                                                                                            8       20 (12.4)              0.
                                                                                                                       9       30 (18.6)              0.
                                                                                                                      10       40 (24.9)              0.
                                                                                                                      11       50 (31.1)              0.
                                                                                                                      12       60 (37.3)              0.
S1b...............  Adult...........  Walk............  Right...........              50  No...............           13        10 (6.2)        5 (3.1).
                                                                                                                      14       20 (12.4)        5 (3.1).
                                                                                                                      15       30 (18.6)        5 (3.1).
                                                                                                                      16       40 (24.9)        5 (3.1).
                                                                                                                      17       50 (31.1)        5 (3.1).
                                                                                                                      18       60 (37.3)        5 (3.1).
S1a...............  Adult...........  Walk............  Right...........              25  No...............           19        10 (6.2)        5 (3.1).
                                                                                                                      20       20 (12.4)        5 (3.1).
                                                                                                                      21       30 (18.6)        5 (3.1).
                                                                                                                      22       40 (24.9)        5 (3.1).
                                                                                                                      23       50 (31.1)        5 (3.1).
                                                                                                                      24       60 (37.3)        5 (3.1).
S1e...............  Adult...........  Run.............  Left............              50  No...............           25        10 (6.2)        8 (5.0).
                                                                                                                      26       20 (12.4)        8 (5.0).
                                                                                                                      27       30 (18.6)        8 (5.0).
                                                                                                                      28       40 (24.9)        8 (5.0).
                                                                                                                      29       50 (31.1)        8 (5.0).
                                                                                                                      30       60 (37.3)        8 (5.0).

[[Page 96020]]

 
S1d...............  Child...........  Run.............  Right...........              50  Yes..............           31        10 (6.2)        5 (3.1).
                                                                                                                      32       20 (12.4)        5 (3.1).
                                                                                                                      33       30 (18.6)        5 (3.1).
                                                                                                                      34       40 (24.9)        5 (3.1).
--------------------------------------------------------------------------------------------------------------------------------------------------------
*All darkness testing is to occur without the use of overhead artificial lighting.

VI. Adding Blind Spot Technologies

    NHTSA is adding assessments for two blind spot technologies, blind 
spot warning (BSW) and blind spot intervention (BSI), to NCAP's crash 
avoidance program. As discussed in NHTSA's March 2022 RFC notice, these 
technologies have the potential to prevent or mitigate five pre-crash 
lane change or merge scenarios, representing approximately 503,070 
crashes annually, on average--8.7 percent of all crashes that occur on 
U.S. roadways. These crashes result in 542 fatalities on average, and 
188,304 MAIS 1-5 injuries annually, representing 1.6 percent of all 
fatalities and 6.7 percent of all injuries, respectively.\297\ While 
the target population for blind spot technologies may not be as large 
as the populations for AEB technologies, their high consumer acceptance 
rate and potential safety improvements, both discussed later in this 
section, support their inclusion in the Agency's signature consumer 
information program.
---------------------------------------------------------------------------

    \297\ Wang, J.S. (2019, March), Target crash population for 
crash avoidance technologies in passenger vehicles (Report No. DOT 
HS 812 653). Washington, DC: National Highway Traffic Safety 
Administration.
---------------------------------------------------------------------------

A. Blind Spot Technologies

1. Blind Spot Warning (BSW)
    A BSW system is a warning-based driver assistance system that 
automatically alerts a driver that another vehicle is approaching, or 
being operated within, the blind spot of the driver's vehicle in an 
adjacent lane. Depending on the system design, additional BSW features 
may be activated if the system presents an alert and the driver 
operates their turn signal indicator. In either case, the BSW system 
provides information intended to assist a driver contemplating or 
initiating a lane change.
    Current BSW systems use camera-, radar-, or ultrasonic-based 
sensors, or some combination thereof, to detect other vehicles. These 
sensors are typically located on the sides and/or rear of a vehicle. 
BSWs may be auditory, visual (most common), or haptic. Visual alerts 
are usually presented in the outboard side mirror glass, inside edge of 
the mirror housing, or at the base of the front A-pillars inside the 
vehicle. When the BSW system detects that another vehicle traveling in 
an adjacent lane has entered or is approaching the driver's blind spot, 
the BSW visual alert is typically continuously illuminated. However, if 
the driver engages the turn signal in the direction of the adjacent 
vehicle while the visual alert is present, the visual alert may 
transition to a flashing state and/or be supplemented with an 
additional auditory or haptic alert (e.g., beeping or vibration of the 
steering wheel or seat, respectively).
    Adding BSW systems to NCAP's ADAS evaluations is appropriate not 
only because the technology addresses a safety need but also because of 
consumer interest and known differences in detection capabilities and 
operating conditions, the latter of which can impact system 
effectiveness. The general appeal of BSW systems is reflected by the 
systems' penetration rates. In the six years between model years 2018 
and 2024, the percentage of the fleet fitted with standard BSW systems 
rose from 5.8 to 57 percent. Further, in market research conducted by 
Consumer Reports, the organization found an overwhelming majority of 
vehicle owners were satisfied with BSW technology, and 60 percent of 
those surveyed believed BSW technology had helped them avoid a 
crash.\298\ Additionally, in a study evaluating the real-world 
effectiveness of ADAS technologies in model year 2013 to 2017 GM 
vehicles, UMTRI found BSW system effectiveness increased substantially 
(i.e., translating to a larger reduction in lane-change crashes) for 
systems offering longer vehicle detection ranges.299 300 
Whereas one vehicle's BSW system may simply augment a driver's visual 
awareness, another may more effectively prevent crashes by warning of 
potential higher speed differential lane change conflicts. As such, 
there are reasons to provide consumers with BSW system performance 
information, regardless of the technology's high equipment rates and 
consumers' positive appreciation for such systems.
---------------------------------------------------------------------------

    \298\ Monticello, M. (2017, June 29), The positive impact of 
advanced safety systems for cars: The latest car-safety technologies 
have the potential to significantly reduce crashes, Consumer 
Reports, https://www.consumerreports.org/car-safety/positive-impact-of-advanced-safety-systems-for-cars/.
    \299\ Leslie, A.J., Kiefer, R.J., Meitzner, M.R., & Flannagan, 
C.A. (2019), Analysis of the field effectiveness of General Motors 
production active safety and advanced headlighting systems, The 
University of Michigan Transportation Research Institute and General 
Motors LLC, UMTRI-2019-6.
    \300\ UMTRI found systems having longer vehicle detection ranges 
provided an estimated 26 percent reduction in lane change crashes, 
compared to a corresponding non-significant 3 percent reduction for 
those systems having shorter detection ranges.
---------------------------------------------------------------------------

Proposed BSW Test Procedure
    The Agency proposed to utilize its draft blind spot detection (BSD) 
test procedure \301\ (referred to in this notice as BSW) to assess 
systems' performance and capabilities in blind spot related pre-crash 
scenarios. This test procedure evaluates a vehicle's BSW system using 
two tests performed on the test track: the Straight Lane Converge and 
Diverge Test and the Straight Lane Pass-by Test. These tests assess 
whether a test vehicle's (SV's) BSW system presents a warning when 
other vehicles (POVs) are within or approaching the driver's blind 
spot, or blind zone.\302\ In each test, the POV represents a high-
production mid-sized passenger car.\303\ In the proposed procedure, 
neither the SV nor POV turn signals may be activated at any point 
during any test trial. A short description of each proposed test 
scenario and the

[[Page 96021]]

related requirement for a passing result is provided below.
---------------------------------------------------------------------------

    \301\ Docket No. NHTSA-2019-0102-0010.
    \302\ A vehicle's blind zone is defined by two 2.5 m- (8.2 ft.-) 
wide rectangular regions that extend to the side and rear of the SV 
and begin at the rearmost part of the SV's side mirror housing, in 
the housing's fully extended operating position, and runs 
perpendicular to the SV's longitudinal centerline. The length of the 
blind zone is dependent upon the speed differential between the SV 
and the POV. See Blind Spot Detection System Confirmation Test for a 
complete definition.
    \303\ The POV selected must be 445 to 500 cm (175 to 197 in.) in 
length and 178 to 193 cm (70 to 76 in.) wide, measured at the widest 
part of the vehicle exclusive of signal lamps, marker lamps, outside 
rearview mirrors, flexible fender extensions, and mud flaps. Width 
is determined with doors and windows closed and the wheels in the 
straight-ahead position. The color of the vehicle is unrestricted.
---------------------------------------------------------------------------

     Straight Lane Converge and Diverge Test--The POV and SV 
are driven parallel to one another in the outbound lanes of a three-
lane straight road. Both vehicles are driven at a constant speed of 
72.4 kph (45 mph) and are positioned such that the frontmost part of 
the POV is 1.0 m (3.3 ft.) ahead of the rearmost part of the SV. After 
3.0 s of steady-state driving, the POV enters (i.e., converges into) 
the SV's blind zone by making a single lane change into the lane 
immediately adjacent to the SV using a lateral velocity of 0.25 to 0.75 
m/s (0.8 to 2.5 ft./s). The period of steady-state driving resumes for 
at least another 3.0 s and then the POV exits (i.e., diverges from) the 
SV's blind zone by returning to its original travel lane using a 
lateral velocity of 0.25 to 0.75 m/s (0.8 to 2.5 ft./s). This test is 
repeated for a POV approach from both the left and the right side of 
the SV.

    --To pass a test trial, during the converge lane change, the BSW 
must be presented by a time no later than 300 ms after any part of the 
POV enters the SV blind zone and must remain on while any part of the 
POV resides within the SV blind zone. Additionally, during the diverge 
lane change, the BSW may remain active when the lateral distance 
between the SV and POV is greater than 3 m (9.8 ft.) but less than or 
equal to 6 m (19.7 ft.). The BSW shall not be active once the lateral 
distance between the SV and POV exceeds 6 m (19.7 ft.).
[GRAPHIC] [TIFF OMITTED] TN03DE24.012

     Straight Lane Pass-by Test--The POV approaches and then 
passes the SV while being driven in an adjacent lane. For each trial, 
the SV is traveling at a constant speed of 72.4 kph (45 mph) whereas 
the POV is traveling at one of four constant speeds: 80.5, 88.5, 96.6, 
or 104.6 kph (50, 55, 60, or 65 mph). The lateral distance between the 
two vehicles, defined as the closest lateral distance between adjacent 
sides of the two-dimensional polygons used to represent each vehicle's 
dimensions, shall nominally be 1.5 m (4.9 ft.) for the duration of the 
trial. This test is repeated for a POV approach towards the SV from an 
adjacent lane to the left and to the right of the SV.

    --To pass a test trial, the BSW must be presented by a time no 
later than 300 ms after the frontmost part of the POV enters the SV 
blind zone and remain on while the frontmost part of the POV resides 
behind the frontmost part of the SV blind zone. The BSW shall not be 
active once the longitudinal distance between the frontmost part of the 
SV and the rearmost part of the POV exceeds the BSW termination 
distance specified for each POV speed.

[[Page 96022]]

[GRAPHIC] [TIFF OMITTED] TN03DE24.013

    NHTSA's proposed test procedure stipulates that each scenario be 
tested using seven repeated trials for each combination of approach 
direction (left and right side of the SV) and test speed. This 
translates to a total of 14 tests overall for the Straight Lane 
Converge and Diverge Test and 56 tests overall for the Straight Lane 
Pass-by Test. In its RFC notice, the Agency proposed that the SV must 
pass at least five out of seven trials conducted for each approach 
direction and test speed to pass the NCAP system performance 
requirements. Tests that NHTSA proposed for NCAP BSW testing are shown 
below in Table 21.

                                               Table 21--Blind Spot Warning (BSW) Proposed Test Conditions
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                           SV speed (kph  POV speed (kph                                                                     Number of
              Test scenario                   (mph))          (mph))         POV direction of approach              Turn signal               trials
--------------------------------------------------------------------------------------------------------------------------------------------------------
Straight Lane Converge and Diverge......       72.4 (45)       72.4 (45)  Right.........................  Disabled......................               7
                                                                          Left..........................  Disabled......................               7
Straight Lane Pass-by...................       72.4 (45)       80.5 (50)  Right.........................  Disabled......................               7
                                                                          Left..........................  Disabled......................               7
                                               72.4 (45)       88.5 (55)  Right.........................  Disabled......................               7
                                                                          Left..........................  Disabled......................               7
                                               72.4 (45)       96.6 (60)  Right.........................  Disabled......................               7
                                                                          Left..........................  Disabled......................               7
                                               72.4 (45)      104.6 (65)  Right.........................  Disabled......................               7
                                                                          Left..........................  Disabled......................               7
--------------------------------------------------------------------------------------------------------------------------------------------------------

Model Year 2019 and 2020 Research Testing
    In 2020, NHTSA utilized its proposed BSW test procedure to conduct 
a series of tests on 10 model year 2019 and 2020 vehicles to evaluate 
then-current BSW systems.\304\ The Agency selected test vehicles 
equipped with BSI technology, and the same vehicles were also subjected 
to BSI testing, as detailed in the next section.
---------------------------------------------------------------------------

    \304\ Test reports detailing the results for this research can 
be found in docket NHTSA-2021-0002.
---------------------------------------------------------------------------

    The Agency's testing showed that most of the model year 2019 and 
2020 vehicles failed at least one trial throughout the course of 
testing. Half of the vehicles (five out of ten) only failed trials for 
one of the two test scenarios (i.e., either the Straight Lane Pass-by 
test or the Straight Lane Converge and Diverge Test). Additional data 
findings will be discussed in the sections to follow.
2. Blind Spot Intervention (BSI)
    Blind spot intervention (BSI) systems are similar to AEB systems in 
that they provide active intervention to help the driver avoid a 
collision with another vehicle. While BSW systems alert a driver that 
another vehicle is in their vehicle's blind spot, BSI systems 
automatically provide a steering input to guide the driver's vehicle 
back into the unobstructed lane when the BSW is ignored and/or apply 
the vehicle's brakes. Thus, BSI systems actively intervene to help a 
driver avoid collisions with other vehicles that are approaching or 
operating within the vehicle's blind spot.
    Like BSW systems, BSI systems utilize rear-facing sensors to detect 
other vehicles next to or behind the vehicle in adjacent lanes. 
Depending on the design of these systems, BSI activation may or may not 
require the driver to operate their turn signal indicator during a lane 
change. In addition, some BSI systems may only operate if the vehicle's 
BSW system is also enabled.

[[Page 96023]]

    Unlike BSW systems, BSI systems are not widely available in the 
current fleet, with only 29 percent of model year 2024 vehicles 
equipped with BSI systems as standard equipment. NHTSA is unaware of 
any effectiveness studies for this technology, which is only beginning 
to penetrate the fleet. Nonetheless, as mentioned previously, the 
Agency expects that active safety technologies are more effective than 
warning technologies. For example, UMTRI's study of 2013-2017 GM 
vehicles concluded that AEB is more effective than FCW alone, and that 
LKA is more effective than LDW.\305\ The same relationship will likely 
hold true for blind spot systems, and that BSI will be more effective 
than BSW alone. Also, adopting ADAS technologies such as BSI into NCAP 
should encourage the development and robustness of enhanced BSW system 
capabilities (e.g., motorcycle and bicycle detection).
---------------------------------------------------------------------------

    \305\ Leslie, A.J., Kiefer, R.J., Meitzner, M.R., & Flannagan, 
C.A. (2019), Analysis of the field effectiveness of General Motors 
production active safety and advanced headlighting systems, The 
University of Michigan Transportation Research Institute and General 
Motors LLC, UMTRI-2019-6.
---------------------------------------------------------------------------

    By including BSI as a recommended technology in NCAP, NHTSA 
anticipates manufacturers will equip a larger portion of the fleet with 
BSI systems. Furthermore, by adopting objective test procedures to 
gauge system performance for NCAP's assessments, the Agency will best 
ensure that future BSI systems most effectively address the safety need 
stemming from lane change and merge crashes.
Proposed BSI Test Procedure
    NHTSA proposed to use its published draft test procedure titled, 
``Blind Spot Intervention System Confirmation Test,'' to evaluate the 
performance of vehicles equipped with BSI technology in NCAP. The 
Agency's test procedure consists of three scenarios: SV Lane Change 
with Constant Headway, SV Lane Change with Closing Headway, and SV Lane 
Change with Constant Headway, False Positive Assessment. In the first 
two scenarios, a test vehicle (SV) initiates a lane change into an 
adjacent lane while a single other vehicle (POV) resides within the 
SV's blind zone (Scenario 1) or approaches it from the rear (Scenario 
2). The third scenario is used to evaluate the propensity of a BSI 
system to activate inappropriately in a non-critical driving scenario 
that does not present a safety risk to the occupants in the SV. In each 
of the tests, the POV is a strikeable vehicle test device with the 
characteristics of a compact passenger car. The SV's turn signal is 
activated in each test trial. A short description of each test scenario 
and the proposed evaluation criteria are detailed below.

    --SV Lane Change with Constant Headway Test--The POV is driven at 
72.4 kph (45 mph) in a lane adjacent and to the left of the SV also 
traveling at 72.4 kph (45 mph) with a constant longitudinal offset such 
that the frontmost part of the POV is 1 m (3.3 ft.) ahead of the 
rearmost part of the SV, which is laterally offset from the center of 
its travel lane. After a short period of steady-state driving, the SV 
driver engages the left turn signal indicator at least 3 s after all 
pre-SV lane change test validity criteria have been satisfied. Within 
1.0  0.5 s after the turn signal has been activated, the SV 
driver initiates a manual \306\ lane change, and follows an 800 m 
(2,625 ft.) radius curved path towards the POV's travel lane. The SV 
driver then releases the steering wheel within 250 ms of the SV exiting 
the curve so as to achieve a steady state lateral velocity of 0.7 
 0.1 m/s (2.3  0.3 ft./s) relative to the line 
separating the SV and POV travel lanes. To pass a test trial, the BSI 
system must intervene to prevent any contact between the SV and the 
POV. Additionally, the SV BSI intervention shall not cause a secondary 
departure (i.e., the SV BSI intervention shall not cause the SV to 
travel 0.3 m (1.0 ft.) or more beyond the inboard edge of the lane line 
separating the SV travel lane from the lane adjacent and to the right 
of it within the validity period).
---------------------------------------------------------------------------

    \306\ ``Manual'' refers to an externally commanded steering 
input. NHTSA will use a steering robot for such inputs to maximize 
accuracy, repeatability, and test efficiency.
[GRAPHIC] [TIFF OMITTED] TN03DE24.014

     SV Lane Change with Closing Headway Test--The POV is 
driven at a constant speed of 80.5 kph (50 mph) towards the rear of the 
SV in an adjacent lane to the left of the SV, which is laterally offset 
from the center of its travel lane and traveling at a constant speed of 
72.4 kph (45 mph). During the test, the SV driver engages the left turn 
signal indicator when the POV is 4.9  0.5 s from a vertical 
plane defined by the rear of the SV and perpendicular to the SV travel 
lane. Within 1.0  0.5 s after the turn signal has been 
activated, the SV driver initiates a manual lane change and follows an 
800 m (2,625 ft.) radius curved path towards the POV's travel lane. The 
SV driver then releases the steering wheel within 250 ms of the SV 
exiting the curve so as to achieve a steady state lateral velocity of 
0.7  0.1 m/s (2.3  0.3 ft./s) relative to the 
---------------------------------------------------------------------------
line separating the SV and POV travel lanes.

    --To pass a test trial, the BSI system

[[Page 96024]]

must intervene to prevent any contact between the SV and the POV. 
Additionally, the SV BSI intervention shall not cause a secondary 
departure (i.e., the SV BSI intervention shall not cause the SV to 
travel 0.3 m (1.0 ft.) or more beyond the inboard edge of the lane line 
separating the SV travel lane from the lane adjacent and to the right 
of it within the validity period).
[GRAPHIC] [TIFF OMITTED] TN03DE24.015

     SV Lane Change with Constant Headway, False Positive 
Assessment Test--The POV is driven at 72.4 kph (45 mph) in a lane that 
is two lanes to the left of the SV's initial travel lane with a 
constant longitudinal offset such that the frontmost part of the POV is 
1 m (3.3 ft.) ahead of the rearmost part of the SV. The SV is laterally 
offset from the center of its travel lane and also travelling at 72.4 
kph (45 mph). The SV driver engages the left turn signal indicator at 
least 3 seconds after all pre-SV lane change test validity criteria 
have been satisfied. Within 1.0  0.5 seconds after the turn 
signal has been activated, the SV driver initiates a manual lane 
change, and follows a defined path into the left adjacent lane (the one 
between the SV and POV), approaching the center lane line at a constant 
lateral velocity of 0.7  0.1 m/s (2.3  0.3 ft./
s). For this test, the driver does not release the steering wheel.

    --To pass a test trial, the SV's BSI system must not intervene 
during any valid trials; the lane change will not result in an SV-to-
POV impact. To determine whether a BSI intervention occurred, the yaw 
rate data collected for the SV during the individual trials performed 
in this scenario are compared to a baseline composite. After being 
aligned in time to the baseline, the difference between the data must 
not exceed 1 degree/second within the test validity period.
[GRAPHIC] [TIFF OMITTED] TN03DE24.016

    Currently, for the three BSI test scenarios, specific test 
procedures and specifications are dependent upon the SAE Driving 
Automation Level being assessed.\307\ The four driving automation 
conditions included in the test procedure are: (1) with manual speed 
control and Lane Centering Assistance (LCA) off (SAE Driving Automation 
Level 0), (2) with cruise control enabled and LCA off (also considered 
SAE Level 0), (3) with ACC

[[Page 96025]]

enabled and LCA off (SAE Level 1), and (4) with ACC on and LCA on 
(initially) and an automatic SV lane change occurs (SAE Levels 2 or 3). 
For condition 4, SV lateral lane position and lane change/path 
tolerance specifications are controlled by the vehicle, not the driver.
---------------------------------------------------------------------------

    \307\ Society of Automotive Engineers (SAE) Standard 
J3016_202104, Taxonomy and Definitions for Terms Related to Driving 
Automation Systems for On-Road Motor Vehicles.
---------------------------------------------------------------------------

    In its March 2022 RFC notice, NHTSA stated that it plans to use the 
[ABD] GVT Revision G as a strikeable vehicle test device when BSI is 
added to NCAP as a recommended ADAS technology to be consistent with 
Euro NCAP's ADAS test procedures that specify a strikeable vehicle test 
device.
    Tests that NHTSA proposed to complete for NCAP BSI testing are 
shown below in Table 22.

                        Table 22--Blind Spot Intervention (BSI) Proposed Test Conditions
----------------------------------------------------------------------------------------------------------------
                                SV speed (kph  POV speed (kph     Lane change                        Number of
        Test scenario              (mph))          (mph))          direction       Turn signal        trials
----------------------------------------------------------------------------------------------------------------
SV Lane Change with Constant        72.4 (45)       72.4 (45)  Left............  Enabled........               7
 Headway.
SV Lane Change with Closing         72.4 (45)       80.5 (50)  Left............  Enabled........               7
 Headway.
SV Lane Change with Constant        72.4 (45)       72.4 (45)  Left............  Enabled........               7
 Headway, False Positive
 Assessment.
----------------------------------------------------------------------------------------------------------------

Model Year 2019 and 2020 Research Testing
    NHTSA utilized its proposed BSI test procedure to conduct a series 
of research tests on model year 2019 and 2020 vehicles to assess the 
performance of then-current BSI systems.\308\ When selecting vehicles 
for testing, an attempt was made to choose one test vehicle from as 
many manufacturers as possible that had implemented BSI technology at 
the time. As mentioned previously, selected vehicles were also 
subjected to BSW testing. An ABD GVT Revision G represented the POV 
during testing. Results from this test series suggested there is an 
opportunity for performance improvement, as most vehicles failed both 
the SV Lane Change with Constant Headway Tests and the SV Lane Change 
with Closing Headway Tests.
---------------------------------------------------------------------------

    \308\ Test reports detailing the results for this research can 
be found in docket NHTSA-2021-0002.
---------------------------------------------------------------------------

B. Linking Proposed BSW and BSI Test Scenarios to Real-World Crashes

    As mentioned in the March 2022 RFC notice, the BSW and BSI tests 
proposed by the Agency represent pre-crash scenarios that correspond to 
a substantial portion of fatalities and injuries observed in real-world 
lane change crashes. A review of Volpe's 2011-2015 data set showed 
that, for crashes where posted speed limit was known, approximately 29 
percent of fatalities and 70 percent of injuries in lane change crashes 
occurred on roads with posted speeds of 72.4 kph (45 mph) or 
lower.309 310 For crashes where the travel speed was 
reported in FARS and GES, approximately 44 percent of fatalities and 81 
percent of injuries occurred at speeds of 72.4 kph (45 mph) or 
lower.\311\ Volpe found that speeding was a known factor in 18 percent 
of the fatal lane change crashes and 3 percent of lane change crashes 
that resulted in injuries. This suggests that posted speed may 
correspond well to travel speed in most lane change 
crashes.312 313
---------------------------------------------------------------------------

    \309\ The posted speed limit was either not reported or was 
unknown in 2 percent of fatal lane change crashes and 18 percent of 
lane change crashes that resulted in injuries.
    \310\ The lane change pre-crash scenarios referenced included 
(1) turning/same direction, (2) parking/same direction, (3) changing 
lanes/same direction, and (4) drifting/same direction crashes.
    \311\ The travel speed was either not reported or was unknown in 
60 percent of fatal lane change crashes and 68 percent of lane 
change crashes that resulted in injuries.
    \312\ Swanson, E., Foderaro, F., Yanagisawa, M., Najm, W.G., & 
Azeredo, P. (2019, August), Statistics of light-vehicle pre-crash 
scenarios based on 2011-2015 national crash data (Report No. DOT HS 
812 745), Washington, DC: National Highway Traffic Safety 
Administration.
    \313\ It was unknown or not reported whether speeding was a 
factor in 3 percent of fatal lane change crashes and 7 percent of 
lane change crashes that resulted in injuries.
---------------------------------------------------------------------------

    Roadway alignment and grade for real-world lane change crashes also 
align with those used in NHTSA's procedures. For those crashes where 
roadway alignment was known in Volpe's 2011-2015 FARS and GES data set, 
88 percent of fatal and 93 percent of injurious lane change crashes 
occurred on straight roads.\314\ Furthermore, 77 percent and 86 percent 
of fatal and injurious lane change crashes, respectively, occurred on 
level roadways.\315\
---------------------------------------------------------------------------

    \314\ Roadway alignment was unknown or not reported in 1 percent 
of fatal lane change crashes and 4 percent of lane change crashes 
that resulted in injuries.
    \315\ Roadway grade was unknown or not reported in 5 percent of 
fatal lane change crashes and 18 percent of lane change crashes that 
resulted in injuries.
---------------------------------------------------------------------------

C. Summary of Comments, Response to Comments, and Agency Decisions

1. Blind Spot Technology Inclusion in General
    The Agency noted that commenters overwhelmingly supported the 
addition of BSW in response to its December 2015 notice regarding NCAP 
updates, and these sentiments were reiterated in the comments received 
in response to the March 2022 RFC notice. Many groups and individuals 
submitted comments supporting inclusion of both BSW and BSI in NCAP. 
MEMA expressed that BSW and BSI offer ``significant'' safety benefits. 
ITS America agreed that NHTSA provided sufficient evidence for 
benefits. Advocates and CFA noted that the test criteria seemed 
reasonable and that automatic intervention with BSI will provide 
greater benefits than BSW alone.
    Honda supported the eventual inclusion of BSW and BSI technologies 
based on potential benefits but requested that NHTSA use a phased 
approach when adding these technologies to NCAP. The automaker further 
noted that the Agency included the warning technologies LDW and FCW 
first before proposing to add the respective active technologies, LKA 
and AEB, in NCAP. Thus, the Agency should consider following the same 
process for blind spot technologies. Although Honda acknowledged that 
``active safety technologies are more effective than warning 
technologies,'' the manufacturer stated that it was not aware of 
specific effectiveness data for BSI, as it is relatively new compared 
to the other three new technologies proposed (i.e., BSW, LKA, and 
PAEB). As such, Honda stated that BSI does not fulfill the Agency's 
four prerequisites for NCAP inclusion at the current time and requested 
that NHTSA wait until effectiveness data becomes available for BSI 
before including it in an NCAP rating.
    GM and Auto Innovators agreed with Honda's sentiments regarding the 
absence of effectiveness data for BSI. However, Auto Innovators 
acknowledged there is some effectiveness data available for BSW, 
``depending on system design.'' The

[[Page 96026]]

groups also stated that while BSW and BSI technologies may be helpful, 
the target populations for BSW and BSI are relatively small. Given 
these concerns, Auto Innovators did not support adding BSI into an ADAS 
rating and requested that NHTSA include BSI research in the NCAP 
roadmap. However, the group had no objection to adding BSI as an ``NCAP 
Recommended Technology'' and was not opposed to including BSW in the 
program. Meanwhile, GM did not recommend including either BSW or BSI. 
The manufacturer stated that ``any future BSI field effectiveness 
studies need to account for redundancies with other related ADAS 
features with proven safety benefits, such as LKS, LDW, and [GM's] Lane 
Change Alert (``LCA'').'' Regarding BSW inclusion, GM shared data from 
a 2022 effectiveness study of over 10.9 million GM model year 2013 to 
2020 vehicles, which found that NHTSA's proposed BSW technology did not 
yield statistically significant field safety benefits. The automaker 
asserted that ``the non-statistically significant level observed for 
[GM's] BSW (which is a short-range detection system) was less than half 
that observed for [the manufacturer's] LCA (which can be thought of as 
``Long Range'' BSW), which yielded statistically significant 
benefits.''
2. Test Conditions for BSW Testing, Including the Straight Lane Pass-by 
Test Scenario With Varying Speed Differentials
    As previously described, NHTSA's March 2022 proposal for NCAP BSW 
test scenarios included a Straight Lane Converge and Diverge test 
scenario and a Straight Lane Pass-by test scenario. Within each 
scenario, NHTSA proposed to perform testing in multiple test conditions 
by varying POV approach directions. Within the Straight Lane Pass-by 
scenario, a variety of POV speeds were also introduced.
    The Agency also expressed its interest in minimizing the testing 
burden whenever possible. As such, NHTSA requested comments on whether 
all test conditions should be performed to address real-world concerns, 
and if not, which ones should be prioritized. Specifically, the Agency 
mentioned possibly incorporating only the most challenging test 
conditions, selecting the highest and lowest speed conditions, and/or 
assuming symmetry to test only one side of the SV and apply results to 
the other side.
    NHTSA also recognized that lane-change crashes associated with high 
speed differentials between involved vehicles may be more severe than 
those in which vehicle speeds are more similar. Since the ability to 
mitigate these higher-severity crashes is desirable, NHTSA requested 
comment on use of the Straight Lane Pass-by test procedure with varying 
POV-to-SV speed differentials to distinguish between basic and advanced 
BSW system capabilities. The Agency suggested that an SV that can only 
satisfy the BSW activation criteria when the POV approaches with a low 
relative velocity may be considered as having basic BSW capability, 
whereas a vehicle that can look further rearward to sense a passing 
vehicle travelling at a much higher speed may be considered to have 
superior detection abilities. The Agency added that the ability of a 
BSW system to provide long-range vehicle detection could increase the 
effectiveness of BSI systems and SAE Driving Automation Level 2 partial 
driving automation systems that incorporate automatic lane change 
features as well.
Summary of Comments
    TRC suggested the scenarios proposed were sufficient and offered 
``good coverage'' of real-world cases. Bosch also agreed that both 
proposed scenarios should be included, with the Straight Lane Pass-by 
Test differentiating between basic and advanced system capabilities and 
the Straight Lane Converge and Diverge Test assessing whether the SV 
can sense POVs travelling at the same speed. CAS stated it would be 
premature to only consider testing the most stringent scenarios, citing 
concern that manufacturers would begin designing to the test rather 
than to a range of conditions. The group further stated that the Agency 
should perform all test scenarios and conditions to ensure it addresses 
the variety of real-world conditions. Toyota noted that it has concerns 
regarding the timely release of information to consumers. Toyota also 
opined that if testing at a certain speed or in a specific scenario 
will adequately ensure acceptable performance in the entire speed range 
or in all similar cases, the Agency should consider running that test 
speed/scenario.
    Tesla recommended NHTSA focus its attention on high-risk cases 
where BSW performance tends to be most problematic, specifically noting 
situations with a high speed differential. Similarly, FCA and Bosch 
expressed favor with testing first at the most stringent test case and, 
should the vehicle fail, slowly decreasing the stringency until the 
vehicle passes. The manufacturers conveyed that this strategy would 
allow NHTSA to more quickly determine the highest speed at which the 
BSW system can reliably function. FCA noted that manufacturers are most 
likely already testing their vehicles at mid-range speeds to ensure 
system robustness.
    Conversely, ZF Group, ASC, BMW, Rivian, Auto Innovators, and Toyota 
recommended that NHTSA test at both low and high speeds. ZF Group and 
ASC mentioned that, in cases where there is a large performance 
differential between low and high speeds, a mid-range test speed may 
also be appropriate. Rivian noted that even with a mid-range test 
added, this strategy would result in a reduction of test speeds from 
four to three. Though FCA suggested starting at the most stringent test 
case, the automaker also noted that the Agency could test at low and 
high speeds as defined by each manufacturer.
    ASC also supported NHTSA performing a low-speed SV scenario with 
high relative POV speed to approximate cases where the SV is in a 
slower-moving lane but intends to change into a faster-moving lane, as 
is the case in traffic congestion. Similarly, Vayyar requested that 
low-speed, or even stationary, POV tests be conducted to address real-
world cases where target vehicles are stopped or moving slowly.
    Auto Innovators asserted that the test speeds selected should be 
based on several factors: test laboratory specifications such as 
available test lane length, real-world crash data, capabilities of the 
POV vehicle test device, and the minimum operational speed of BSW 
systems. GM agreed with this justification for test speed selection. 
Advocates stated that the chosen scenarios and conditions should be 
able to help consumers identify vehicles which meet a minimum 
performance and discern between systems of minimal and higher 
performance.
    Regarding symmetry, Toyota mentioned left-to-right symmetry 
specifically and suggested that the Agency could randomize the test 
side selected to encourage symmetrical designs. ZF Group, Tesla, BMW, 
ASC, Auto Innovators, and GM also noted that assuming symmetry would 
reduce the number of tests needed, stating data could be provided to 
prove symmetrical responses. However, DRI, Rivian, and Bosch asserted 
that NHTSA should still consider testing both sides of the vehicle. DRI 
explained that, in its experience, BSW performance differs from one 
side of the SV to the other. Rivian stated that performance can differ 
between sides due to differences in radar hardware location and that 
testing only one side of the vehicle might lead to BSW systems that do 
not offer strong real-world safety

[[Page 96027]]

performance. Rivian also noted that manufacturers may ignore any 
discrepancies in left-to-right side design. Finally, Bosch stated both 
sides of the vehicle should be tested to ensure system robustness.
Straight Lane Pass-by Test With Speed Differentials To Discern 
Differences in Performance
    Bosch, ZF Group, Toyota, CAS, BMW, Tesla, FCA, Auto Innovators, GM, 
and ASC agreed that NHTSA could vary test speeds in the Straight Lane 
Pass-by test scenario to differentiate performance between vehicles. 
BMW's support was bolstered by its assertion that the Straight Lane 
Pass-by Test evaluates the capability of both hardware (sensor) and 
software (functional logic). ZF Group stated that systems which 
mitigate crashes with higher speed differentials are more likely to 
improve safety in a broad range of lane-change events and therefore 
should warrant a higher score or rating. ASC echoed these sentiments, 
noting that high relative speed differentials between lanes can occur 
during real-world driving even though speed limits exist because of 
road work, traffic, and other commonly encountered scenarios. Further, 
GM suggested 24.1, 32.2, 48.3, and 64.4 kph (15.0, 20.0, 30.0, and 40.0 
mph) speed differentials, and mentioned that, in its experience, 
varying test speeds is not as effective at distinguishing BSW 
performance as varying the speed differentials between the POV and the 
SV.
    Toyota noted that drivers need as much time to react to threats as 
possible and speed-based warning timing is preferable since a POV 
approaching at a high speed will require relatively early warning. Auto 
Innovators reiterated this by stating that testing at varying speeds 
could differentiate products that offer detection within the blind zone 
only (basic performance capability) versus products that have an 
expanded rearward field of view to detect a vehicle advancing at a 
higher rate of travel (advanced performance capability). ASC also 
discussed this expanded rearward field of view, detailing the 
difference between Blind Spot Assist (BSA) systems, which are meant to 
mitigate short-range POV-SV scenarios, and Lane Change Assist (LCA) 
systems, which address longer-range POV-SV scenarios. The group voiced 
support for both scenarios proposed, stating that the Straight Lane 
Converge and Diverge test is a suitable evaluation for BSA systems 
while the Straight Lane Pass-by test is best for LCA systems. ASC also 
stated that LCA systems are more commonly found in countries without 
posted speed limits, whereas BSA is typically offered in countries 
where the posted speed limit is 80 mph or less. ASC suggested that, in 
these latter countries, the speed differential between lanes and 
vehicles is generally low. Finally, GM stated that only long-range LCA 
systems have been shown to reduce feature-relevant lane-change crashes, 
and therefore, only recommended that the Straight Lane Pass-by test be 
performed.
Response to Comments and Agency Decisions
    This notice finalizes NHTSA's proposal including both the Straight 
Lane Converge and Diverge and Straight Lane Pass-by scenarios for its 
BSW tests.
    For the Straight Lane Converge and Diverge test (shown in Figure 
13), the test will begin with the POV two lanes away from the SV on a 
straight road. The vehicles will be positioned such that the frontmost 
part of the POV is 1.0 m (3.3 ft.) ahead of the rearmost part of the 
SV. Both vehicles will be driven in this formation at a constant speed 
of 72.4 kph (45 mph) for 3.0 seconds. The POV will then perform a 
single lane change into the lane adjacent to the SV (i.e., the center 
lane) using a lateral velocity of 0.25 to 0.75 m/s (0.8 to 2.5 ft./s). 
Once the lane change is completed, the POV will continue to be driven 
in the lane adjacent to the SV for at least 3.0 seconds, and then will 
perform a lane change back into its original outboard lane using a 
lateral velocity of 0.25 to 0.75 m/s (0.8 to 2.5 ft./s). This test will 
be repeated for a POV approach from both the left and the right side of 
the SV (with and without the SV's turn signal engaged).
    For the Straight Lane Pass-by Test (shown in Figure 14), the POV 
will approach and then pass the SV while being driven in an adjacent 
lane on a straight road. For each trial, the SV will travel at a 
constant speed of 72.4 kph (45 mph) whereas the POV will travel at one 
of four constant speeds: 80.5, 88.5, 96.6, or 104.6 kph (50, 55, 60, or 
65 mph). The lateral distance between the two vehicles will nominally 
be 1.5 m (4.9 ft.) for the duration of each trial. This test will be 
repeated for a POV approach towards the SV from an adjacent lane to the 
left and to the right of the SV (with and without the turn signal 
engaged).
    The Agency maintains that both of these BSW scenarios align with 
real-world data and are therefore appropriate for inclusion in NCAP. As 
mentioned previously, the 72.4 kph (45 mph) SV test speed adopted for 
both BSW scenarios proposed was found to cover a significant portion of 
fatalities and injuries, and an overwhelming majority of lane-change 
crashes occurred on straight roads. The adopted scenarios also 
encompass both ways a vehicle may approach another vehicle's blind zone 
when the driver does not first directly see the vehicle: laterally from 
two lanes away and longitudinally from behind, on both sides of the 
vehicle.
    For both test scenarios, the POV is defined in NHTSA's updated BSW 
test procedure as either the ABD GVT Revision G or a high-production, 
compact passenger car.\316\ NHTSA added the option to use a surrogate 
vehicle as the POV for BSW testing to align with the option provided in 
its BSI testing procedure. However, the Agency will use an actual 
vehicle as the POV during BSW testing conducted for NCAP assessments. 
This decision should not preclude vehicle manufacturers from using the 
ABD GVT Revision G in their internal testing or preclude NHTSA from 
revisiting its decision in the future.
---------------------------------------------------------------------------

    \316\ The POV selected must be 445 to 500 cm (175 to 197 in.) in 
length and 178 to 193 cm (70 to 76 in.) wide, measured at the widest 
part of the vehicle exclusive of signal lamps, marker lamps, outside 
rearview mirrors, flexible fender extensions, and mud flaps. Width 
is determined with doors and windows closed and the wheels in the 
straight-ahead position. The color of the vehicle is unrestricted.
---------------------------------------------------------------------------

    At this time, both BSW test scenarios will be conducted during 
daylight conditions only. Real-world crash data gathered from 2011 to 
2015 suggests that most lane-change crashes (62 percent of fatal lane-
change crashes and 76 percent of injurious lane-change crashes) 
occurred annually, on average, during daylight hours. For future 
iterations of this consumer information program, NHTSA plans to 
reevaluate the real-world crash data and may adjust the test conditions 
accordingly.
Straight Lane Converge and Diverge Test
    NHTSA received few comments directly related to the Straight Lane 
Converge and Diverge test. Of those commenters specifically addressing 
this test scenario, all but GM were in favor of its inclusion. Although 
NHTSA has taken into consideration GM's statements that this scenario 
may be less effective at reducing lane change crashes compared to the 
Straight Lane Pass-by scenario, the Agency agrees with Bosch that the 
Straight Lane Converge and Diverge test will best ensure that a 
vehicle's BSW system can detect a vehicle entering the blind spot while 
both vehicles are travelling at the same speed. Since NHTSA found that 
only half of the tested vehicles (five out of ten models) passed every 
trial run

[[Page 96028]]

conducted for the Straight Lane Converge and Diverge scenario during 
its model year 2019 and 2020 research testing series,\317\ the Agency 
reasons that it is appropriate to move forward with including the 
Straight Lane Converge and Diverge test scenario in its BSW test series 
for NCAP to ensure adequate BSW system performance for this real-world 
situation. The test will be performed four times--twice with the POV 
approaching the SV from the left side (once with and once without turn 
signal engagement), and twice with the POV approaching from the right, 
as proposed (once with and once without turn signal engagement). This 
should ensure that the SV can detect a POV entering its blind spot from 
either lateral direction. If the SV does not provide a passing warning 
for a run conducted on one side of the vehicle, NHTSA will discontinue 
BSW testing for that vehicle model and the test will not be repeated 
for the vehicle's other side.
---------------------------------------------------------------------------

    \317\ One additional vehicle passed the left POV approach 
direction tests but did not pass one trial (of seven) when the POV 
approached from the right.
---------------------------------------------------------------------------

    The prescribed test speed for both the SV and POV will be 72.4 kph 
(45.0 mph), as proposed. In cases where both the POV and the SV are 
traveling at the same speed, there is no longitudinal speed 
differential; thus, the speed at which the test is conducted is less 
relevant. However, as mentioned, for injurious lane-change crashes from 
2011 to 2015 where posted speed limit was known, nearly three-quarters 
(70 percent) occur on roadways with posted speed limits of 72.4 kph 
(45.0 mph) or less on average annually, suggesting that the proposed 
speed is representative of real-world crashes. Furthermore, a 72.4 kph 
(45.0 mph) test speed is high enough that it should exceed most, if not 
all, vehicle models' BSW minimum speeds for activation. Specifically, 
data from the Agency's annual information collection from vehicle 
manufacturers showed a minimum operational speed range of 0 to 32 kph 
(0 to 19.9 mph) for model year 2024 vehicles, with the average minimum 
operational speed being 10 kph (6.2 mph). The Agency also recognizes 
that a higher test speed may require a larger test area, as both the 
POV and the SV must accelerate to and maintain the test speed until 
testing is completed. As Auto Innovators and GM noted, the Agency is 
aware that it must remain mindful of available test laboratory lane 
length when developing test specifications. Given these considerations, 
a test speed of 72.4 kph (45.0 mph) for both the POV and the SV is 
reasonable for the Straight Lane Converge and Diverge test at this 
time. However, the Agency may consider increasing test speeds in the 
future if doing so would better address the large percentage of 
fatalities (i.e., approximately 70 percent) in lane-change crashes that 
occur at higher posted speeds, though in relatively low numbers.\318\
---------------------------------------------------------------------------

    \318\ In its 2011-2015 data set, Volpe found that for the 
644,099 lane change crashes occurring annually, on average, 752 
resulted in a fatality. This translates to approximately 526 
fatalities that occurred for posted speeds exceeding 72.4 kph (45 
mph).
---------------------------------------------------------------------------

Straight Lane Pass-by Test Speeds
    The second BSW test scenario that this notice finalizes for 
inclusion into NCAP is the Straight Lane Pass-by test. NHTSA notes that 
Euro NCAP currently conducts a Blind-Spot Monitoring scenario similar 
to NHTSA's Straight Lane Pass-by scenario. In the Euro NCAP test, a POV 
passes the SV in an adjacent lane; the vehicles travel at 80 kph (49.7 
mph) and 72 kph (44.7 mph), respectively. Vehicles receive points 
toward Euro NCAP's Human Machine Interface (HMI) score if the vehicle 
provides continuous visual blind spot status information while the POV 
resides in the SV's designated blind spot area.\319\ NHTSA's procedure 
expands upon the Euro NCAP procedure through the inclusion of three 
additional higher POV speeds, which increase the speed differential 
between the POV and SV. Four separate conditions are conducted in 
total, with SV/POV speeds of 72.4/80.5, 72.4/88.5, 72.4/96.6, and 72.4/
104.6 kph (45.0/50.0, 45.0/55.0, 45.0/60.0, and 45.0/65.0 mph, 
respectively). These SV/POV speed pairs result in speed differentials 
equaling 8.1, 16.1, 24.2, and 32.2 kph (5.0, 10.0, 15.0, and 20.0 mph), 
respectively.
---------------------------------------------------------------------------

    \319\ European New Car Assessment Programme (Euro NCAP) 
(December 2023), Assessment Protocol--Safety Assist--Collision 
Avoidance, Version 10.4.
---------------------------------------------------------------------------

    The Agency acknowledges several commenters suggested a reduction in 
the number of test conditions for the Straight Lane Pass-by test to 
reduce test burden. However, NHTSA's BSW research test data from model 
year 2019 and 2020 vehicles demonstrates the need for testing across 
all proposed speed combinations. Specifically, two of the ten vehicle 
models tested passed the lowest 8.1 kph (5 mph) speed differential test 
but failed \320\ all remaining higher speed differential tests.\321\ 
Further, two of the remaining eight vehicle models failed when tested 
at the lowest speed differential (8.1 kph, or 5 mph), while 
successfully passing all higher speed differential tests. Further, of 
the remaining six vehicles, one passed the highest speed differential 
test (32.2 kph, or 20 mph) but failed tests in at least one low-to-mid-
range speed differential.\322\ This demonstrates that not all current 
BSW systems struggle more with greater speed differential pass-by 
tests. The most stringent test case, albeit a lower or higher speed 
differential, is unclear. It may be true, as FCA suggested, that 
vehicle manufacturers test their own vehicles at mid-range speeds. 
However, NHTSA will evaluate all four proposed test speed pairings to 
better evaluate BSW performance in straight lane pass-by conditions 
where the SV is traveling at a moderate speed.
---------------------------------------------------------------------------

    \320\ A failing result was indicative of the SV's inability to 
meet performance criteria on the first run and/or subsequent runs.
    \321\ NHTSA-2021-0002-0002.
    \322\ NHTSA-2021-0002-0002.
---------------------------------------------------------------------------

    Despite the recommendation of several commenters, the Agency is not 
adopting additional test conditions that include higher speed 
differentials for its Straight Lane Pass-by tests. This is because to 
increase the speed differential between the SV and the POV, either the 
SV speed must be reduced or the POV speed must be increased. A 
reduction of the SV speed is inappropriate at this time because many 
BSW systems have minimum speed thresholds which would not be met at a 
lower speed. Increasing the POV speed also does not currently seem 
feasible because test facilities may not have adequate lane length 
available to conduct valid tests. Furthermore, the Agency did not 
initially propose higher speed test conditions, and it has not 
conducted research tests to evaluate cases where the speed delta is 
greater than 32.2 kph (20.0 mph). The Agency may adjust the Straight 
Lane Pass-by test conditions in the future when laboratory testing 
proves feasible.
    Further, the Agency is not adopting a test condition where the SV 
is traveling at very low speed and contemplating a lane change into a 
much faster-flowing lane, despite the request of several commenters. 
These cases occur when traffic flow in a travel lane is slowed (e.g., 
increased traffic, construction, or there is a disabled vehicle ahead). 
As mentioned, there are a range of minimum operating speeds for BSW 
systems, some of which are likely higher than the speed at which a 
vehicle in this presented stop-and-go scenario would be traveling. For 
instance, in data supplied by vehicle manufacturers for the model year 
2024 fleet, the Agency found that, for those vehicles equipped with a 
BSW system, approximately 12 percent have a minimum BSW operating speed 
exceeding 20 kph (12.4 mph). Further, additional research would need

[[Page 96029]]

to be conducted to better understand the conditions, frequency, and 
severity of this crash problem. This is because unlike other scenarios, 
posted speed limits for the roads on which this type of scenario occurs 
likely do not correlate with the travel speed of the SV prior to 
attempting a lane change due to the unexpected nature of the situation. 
Thus, travel speed must be used to understand the scope of the problem 
but is unknown for many crash cases. Crash data from 2011-2015 does 
show that in 16 percent of fatal lane change/merge crashes and in 23 
percent of injurious crashes, travel speed was 64.4 kph (40.0 mph) or 
lower. However, in 60 percent of fatal crash cases and 68 percent of 
injurious crashes, the travel speed prior to the crash was unknown.
    For NCAP's Straight Lane Pass-by testing, NHTSA will conduct the 
lowest speed differential condition (SV/POV speeds of 72.4/80.5 kph 
(45.0/50.0 mph)) first. If the SV provides a passing warning during the 
run, the POV speed will incrementally increase by 8.0 kph (5.0 mph) and 
testing will continue, with one run conducted per speed differential 
condition (each with and without the turn signal engaged), until a POV 
speed of 104.6 kph (65.0 mph) is reached. Testing will then be repeated 
following a similar methodology for POV movement on the opposite side 
of the SV. If, for any speed differential condition, the SV does not 
provide a passing warning, NHTSA will discontinue BSW testing for that 
vehicle model. Test runs for a given speed differential will not be 
repeated upon a vehicle's failure to appropriately warn--a methodology 
consistent with that used for NCAP's AEB and PAEB performance 
evaluations. This test methodology aligns with those adopted for the 
other NCAP AEB and PAEB tests, in which the Agency chose an incremental 
approach to increasing test speeds.
Differentiating BSW System Performance
    NHTSA will not differentiate BSW system performance with this 
upgrade. A vehicle passing three of the four test speed conditions in 
the Agency's Straight Lane Pass-by test will not receive more credit 
than a vehicle that passes two. Instead, a vehicle will need to pass 
all four Straight Lane Pass-by tests for both sides of the vehicle 
(with and without the turn signal engaged) and the Straight Lane 
Converge and Diverge test for both sides of the vehicle (with and 
without the turn signal engaged) to receive credit for its BSW system. 
Based on this, NHTSA concludes that FCA and Bosch's suggestion to 
determine the highest speed at which BSW can function is unnecessary. 
This decision still encourages manufacturers to include technology 
addressing a range of lane-change events, as ZF Group requested, 
because it ensures that the vehicle must pass all BSW test conditions 
for each of the two test scenarios. Further, as ASC asserted, by 
including the Straight Lane Converge and Diverge test in addition to 
the Straight Lane Pass-by test, as well as both low and high speed 
differential conditions for the latter, NHTSA will be able to 
effectively assess performance for a variety of BSW system types (e.g., 
BSA and LCA). Specifically, for the Straight Lane Converge and Diverge 
test, the SV must detect a POV travelling at the same speed at a close 
distance, and BSA systems can best address such situations. For the 
Straight Lane Pass-by test, the SV must detect a faster-moving POV 
farther away to issue the BSW at the appropriate time, and LCA systems 
are best able to address these conditions. Thus, the Agency's BSW 
testing will ensure vehicles' BSW systems provide acceptable 
functionality to cover this range of real-world situations.
    NHTSA will not tailor testing to each manufacturer or model but 
will instead apply the same test conditions to each vehicle model 
assessed. A methodology allowing each manufacturer to supply its own 
minimum and maximum POV speeds for the Agency's assessments, as 
suggested by FCA, would not evaluate models with the same degree of 
stringency, confounding attempts for consumers to compare vehicles 
side-by-side and leading to consumer confusion and misrepresentation.
Testing for Symmetrical System Responses
    The Agency will not assume a symmetrical BSW response by testing 
only one side of the SV. In NHTSA's model year 2019 and 2020 BSW 
research test series, four out of ten vehicle models failed to provide 
a passing warning during at least one trial when the POV approached one 
side of the vehicle but not the other for a particular test condition. 
These findings bolster DRI's comment that BSW performance differs 
depending on which side is tested. Overall, for a given vehicle model, 
the right POV approach condition seemed more challenging than the left 
POV approach condition, but this was not universally true.\323\ Thus, 
without a comprehensive assessment of left-to-right performance, NHTSA 
cannot confirm equivalent, robust system performance. Other approaches 
suggested, such as random selection of sides and/or using manufacturer-
supplied data to determine symmetry, introduce a level of subjectivity. 
Due to the high percentage of vehicle models tested by NHTSA which did 
not offer symmetrical performance across all five test scenarios for 
BSW, the Agency is hesitant to allow testing of only side of the 
vehicle at this time. This is subject to change in the future as 
vehicle hardware and software evolves.
---------------------------------------------------------------------------

    \323\ Of the 10 vehicle models, six failed more trials in right 
POV approach conditions than ones where the POV approached from the 
left. Conversely, one failed more trials for left approach 
conditions, and the remaining three performed approximately the same 
left-to-right.
---------------------------------------------------------------------------

3. Use of the Turn Signal for BSW
    BSWs are automatically presented to the driver when another vehicle 
is operated in, or approaching, the driver's blind spot. These alerts 
may be visual (most common), haptic, or auditory. When the driver 
engages the turn signal to initiate a lane change in the direction of a 
vehicle in the adjacent lane, additional, escalated alerts may also 
activate to warn the driver more urgently that there is already a 
vehicle present.
    NHTSA's current BSW test procedure does not stipulate turn signal 
activation during BSW testing. However, in its RFC notice, the Agency 
sought comments on whether the turn signal indicator should be engaged, 
with the intent to evaluate the additional alerts presented to a driver 
intending to make a lane change rather than only the automatic alert 
presented whenever another vehicle is occupying the blind spot area. If 
commenters were interested in testing with the turn signal enabled, the 
Agency requested further comments regarding the type of alerts that 
should be required (e.g., visual, haptic, and/or auditory) and the 
distinction between alerts issued with and without turn signal usage.
Summary of Comments
Turn Signal Activation
    Several commenters stated that the BSW system should be evaluated 
both with and without the use of the turn signal indicator during 
testing. ZF Group reasoned that both conditions should be tested 
because crashes can occur regardless of whether the turn signal is 
activated. ASC suggested that testing in both configurations can 
determine whether ``the BSW warning is being suppressed for planned 
lane changes where the turn signal indicator is activated.'' Rivian 
commented that NHTSA should run a limited number of tests involving the 
use of the turn signal

[[Page 96030]]

only to ``verify functional logic.'' HATCI requested that finalized 
test procedures be made available before making a decision regarding 
turn signal usage but commented that the procedures should be flexible 
to accommodate.
    While some commenters requested use of the turn signal during 
testing, many stated that testing without the turn signal is critical. 
CAS and others commented that the presence of a vehicle may inform the 
driver's decision to initiate a lane change. Commenters further stated 
that omitting the turn signal more closely represents actual driver 
behavior, as the turn signal is not always engaged before making a 
maneuver. Along these lines, one individual commented that safety 
assessments should be based on likely real-world driver behavior 
instead of idealized behavior. Honda noted that its vehicles' alert 
timing is independent of the driver's intentions and is based on a 
time-to-collision assessment. Bosch stated that, unless NHTSA plans to 
evaluate the warning system itself and not whether it triggers, it is 
not necessary to engage the turn signal.
Alert Type Requirement
    Commenters expressed mixed opinions regarding what types of alerts 
should be required if the BSW test procedure is modified to require 
activation of the turn signal.
Any Alert Type
    Some commenters (Honda, Bosch, HATCI, and one anonymous individual) 
stated that any alert type should be allowed for BSW credit if use of 
the turn signal is stipulated. HATCI expressed that allowing any alert 
modality should give manufacturers flexibility to optimize alerts based 
on the ``multitude of ADAS technology installed, the interactions 
between the technologies, and research and development findings.'' 
Bosch agreed that flexibility was advantageous but added that the same 
alert modalities used for other ADAS should not be used for BSW, since 
this may confuse the consumer and decrease consumer acceptance. Honda 
commented that there is ``no reasonable method to objectively evaluate 
the performance of different alert modalities'' and that doing so could 
complicate the test procedures. HATCI suggested that NHTSA ``consider 
researching performance requirements to measure effectiveness of alerts 
rather than prescribing specific modes'' where appropriate. Auto 
Innovators acknowledged that, while there is potential benefit for an 
escalating alert modality when the turn signal is engaged, the Agency 
should not prescribe a specific alert type.
Visual Warnings
    Many responders commented that visual warnings were sufficient (or 
preferred) for BSW systems. Some commenters mentioned visual warnings 
can be very effective when placed in a natural location for visual 
checking, such as a side mirror. Toyota noted that, ``in the case that 
BSW is not activated, the driver should be still looking at the 
mirror'' to scan for other vehicles prior to a lane change. Thus, a 
change in desired driver behavior would not be required. GM and FCA 
also alluded to the importance of checking mirrors for maneuver 
planning and agreed that drivers should be encouraged to check mirrors 
rather than rely solely on other cues, such as haptic or auditory 
warnings. GM specified that a steady amber warning icon should be 
visible in the side mirror adjacent to the potential threat and should 
flash upon turn signal engagement. GM added that mirror-checking is 
especially important because short-range BSW systems ``have limited 
capability for alerting drivers with enough time to react to fast 
approaching traffic.'' Auto Innovators stated that ``visual alerts only 
are sufficient enough for inclusion in NCAP for evaluations and 
effective alert methods if they are displayed within the driver's field 
of view as they check their mirror before changing lanes.'' Tesla and 
FCA agreed that visual BSWs are sufficient.
Haptic Warnings and/or Auditory Warnings
    NHTSA received varied support for haptic and/or auditory alerts for 
BSW. Some commenters, such as FCA and BMW, asserted that auditory 
warnings can become a nuisance. FCA stated its research has shown that 
an auditory warning can drive customer dissatisfaction when it occurs 
while merging in front of another vehicle and can cause the driver to 
disable the feature altogether. FCA stated it allows the driver to 
disable the auditory BSWs for this reason. BMW offered that drivers 
often engage their turn signals to signal their eventual intent, even 
when they know there is a vehicle in their blind spot. BMW reasoned 
that haptic and/or auditory warnings would annoy the driver in such 
instances. GM submitted similar sentiments regarding non-visual BSWs, 
stating that such alerts would be an annoyance to drivers who have no 
intention of switching lanes, or who signal an intent to change lanes 
in advance of an intended lane change.
    Other commenters stated they would like to see additional alert 
types used for BSW. ZF Group suggested visual warnings may be ``more or 
less effective depending on sunlight'' and that an additional alert 
method might increase robustness of the system. ZF Group stated that 
its research suggests that haptic seat belt warnings are very 
effective; they added that the use of haptic or auditory warnings such 
as those used for LDW could be effective because they are meant to 
convey the same underlying information--the SV is about to experience a 
``potentially hazardous'' lane departure. ASC and GM also agreed with 
these sentiments, with GM commenting that a single alert type (visual) 
could be used when the alert is ``cautionary,'' and multiple alert 
modalities can be used when the situation is more urgent. CAS also 
stated there should be an auditory or haptic warning because the cost 
of adding these alert types to the vehicle would be minimal.
    NHTSA received some feedback suggesting the type of warning should 
depend on the driver's intent. IDIADA shared that its experience has 
been that visual alerts work best for conveying information, not for 
urgently alerting the driver, further noting that an auditory warning 
would be preferable for alerting the driver when attempting to perform 
an unsafe lane change. Vayyar agreed with this sentiment but suggested 
that either an auditory or haptic alert would be acceptable for the 
warning associated with the turn signal. Rivian requested allowing 
users to customize their alert type based on driver preference. Rivian 
stated that visual alerts should not be allowed to be disabled, but 
that an option for auditory alerts should be required and an option for 
haptic alerts should be encouraged.
Alert Distinctions Between Use and Non-Use of Turn Signal
    Regarding distinction between alert modalities associated with and 
without the use of the turn signal, as mentioned previously, most 
commenters agreed that use of the turn signal should increase the 
``urgency'' of the alert issued to the driver. Toyota, CAS, ASC, ZF 
Group, Tesla, BMW, FCA, Rivian, Bosch, and GM all expressed favor with 
the use of a flashing alert specifically to send a more intense signal 
to the driver when the turn signal is used since it conveys intent to 
maneuver. Toyota's reasoning was that a flashing or blinking visual 
warning is normally ``interpreted as conveying `priority'.'' Tesla, 
Auto Innovators, and BMW suggested providing an escalated alert to the 
driver when another vehicle is detected in the

[[Page 96031]]

SV's blind spot and the turn signal is engaged.
    Some commenters stated that the warning indicator should flash 
regardless of driver intent. CAS suggested that LDW/LKA and BSW/BSI be 
integrated so that an ``aggressive warning and correction'' should 
occur if the blind spot is occupied and the driver begins to make a 
hazardous maneuver, regardless of turn signal status, because the cost 
of including a combined warning is minimal. ASC also specified that the 
warning light should flash whether the lane change is intentional or 
not.
    Auto Innovators did not oppose the use of a flashing symbol upon 
activation of the turn signal. However, the organization relayed that 
this is not the only acceptable alert modality and that NHTSA should 
not restrict performance criteria to this type of alert only. Advocates 
also commented that a general escalation should be required and noted 
that a flashing visual warning would be logical; however, it further 
stated that the Agency should provide data to support the alert 
modality ultimately selected to receive credit.
Response to Comments and Agency Decisions
    The Agency has decided to modify its BSW test procedure to require 
additional testing with the turn signal indicator engaged. NHTSA 
appreciates Bosch's position that engaging the turn signal is seemingly 
unnecessary since the Agency plans to only assess whether the warning 
triggers at the appropriate time (i.e., detects the POV when it is in 
the driver's blind spot) and will not evaluate the warning system 
itself. However, the Agency also maintains that there is merit to 
Rivian's suggestion to conduct tests to verify the functionality of the 
BSW system when the turn signal is engaged. This additional testing 
should ensure that a vehicle still issues a BSW when the driver engages 
the turn signal with the intent to switch lanes before fully assessing 
their surroundings, as ASC suggested. Further, as BMW and GM noted, 
utilizing the turn signal to notify intent is a common practice used by 
drivers. Performing testing both with and without the turn signal 
engaged should address the greatest number of real-world driving 
conditions. Although several commenters correctly stated that many 
drivers do not use their turn signal to indicate intent to change 
lanes, many others do. Receiving an alert when another vehicle is 
present may deter this latter group of drivers from completing the lane 
change. Therefore, ensuring that a BSW is issued in either case seems 
appropriate.
    For this NCAP upgrade, the Agency is requiring that FCWs be 
comprised of an auditory and visual signal but is not imposing specific 
attributes (e.g., size, location, decibel level, tactile type, etc.) 
for either signal modality. However, for its BSW tests, NHTSA is not 
only implementing a visual alert requirement, but it is also imposing 
additional alert specifications. Specifically, a visual alert that is 
compliant with SAE Standard J2802, ``Blind Spot Monitoring System 
(BSMS): Operating Characteristics and User Interface'' must be present 
in the side mirror or the A-pillars. The alert must meet the timing 
requirements specified in the Agency's BSW test procedure. Although 
this visual alert requirement will apply to tests conducted both with 
and without use of the turn signal, the type of visual alert displayed 
may change for tests conducted with turn signal engagement. For BSW 
tests conducted without the turn signal engaged, the visual warning 
must be continuously illuminated. When the turn signal is engaged in 
the Agency's BSW tests, the visual warning may become escalatory in 
nature (e.g., switches from steady-burning to flashing, changes color, 
etc.), or may remain continuously illuminated for vehicles where a 
second warning modality is also provided.
    While acknowledging the comments manufacturers provided promoting 
flexibility to optimize alerts for various ADAS technologies, requiring 
a visual alert to appear in the side mirror or A-pillar adjacent to the 
potential crash threat is a reasonable minimum NCAP requirement for BSW 
technology, particularly since the driver's gaze when considering a 
lane change should be in the direction of the intended lane departure. 
As Toyota, GM, FCA, and Auto Innovators mentioned, drivers are expected 
to check their side mirrors or, at a minimum, look left or right, as 
appropriate, to check for the presence of other vehicles prior to 
initiating a lane change. Warnings should serve to assist the driver in 
detecting the presence of vehicles in their blind spots; they should 
not encourage complacency during normal driving. With short-range 
detection capabilities, BSW systems may not always warn drivers with 
enough time for them to react to fast-moving vehicles, as GM stated. As 
such, NHTSA agrees with commenters that the onus remains on the driver 
to be diligent and check their side mirrors before changing lanes, even 
for vehicles equipped with BSW systems.
    In addition to the continuously illuminated visual cue required for 
all BSW tests performed without the SV turn signal engaged, the Agency 
is requiring issuance of an additional alert modality (i.e., a dual-
modality alert) or an escalating visual alert (e.g., switches from 
steady-burning to flashing) upon turn signal engagement, as Auto 
Innovators suggested. With the turn signal engaged, the driver is 
signaling an intent to change lanes, thus altering the significance of 
the alert from a cautionary state to a state of urgency. The Agency 
agrees with GM, IDIADA, and Vayyar that a single alert type (i.e., 
visual) may be sufficient when it serves to caution the driver; 
however, multiple alert modalities or alerts with escalating visual 
attributes are a more effective way to discourage a driver from 
proceeding with an intended action that may cause harm.
    NHTSA recognizes that many commenters preferred use of a flashing 
visual alert when the turn signal is engaged and another vehicle is in 
or approaching the driver's blind spot. Conversely, many others 
expressed that non-visual alert types (e.g., haptic and auditory) can 
be very effective if executed properly. In consideration of this, the 
Agency will allow vehicle manufacturers to dictate the supplemental 
alert type and/or escalation attributes that will be required for BSW 
testing when the turn signal is engaged. A vehicle may present a BSW 
that is comprised of a visual and auditory or visual and haptic signal, 
or it may simply present an alert that exhibits escalating visual 
attributes. Such an approach should allow manufacturers to optimize 
alert strategies not only for BSW systems but also for other ADAS 
technologies in the future, as many commenters requested.
    Although the Agency recognizes that effectiveness may change with 
flash rate, color, etc. for visual warnings; frequency, decibel level, 
etc. for auditory warnings; and tactile type (e.g., vibration, jerk, 
etc.) for haptic warnings, it will not prescribe such requirements at 
this time. NHTSA has not conducted research to guide such 
prescriptions, and, as Honda asserted, it currently has no method to 
objectively evaluate the performance of different BSW modalities. As 
such, it does not want to impose requirements for additional alert 
types that may be of nuisance and create customer dissatisfaction such 
that drivers choose to disable BSW functionality.
    Further, the Agency will not require the BSW visual cue to flash 
when the driver departs the lane absent turn signal engagement, as CAS 
and ASC

[[Page 96032]]

suggested, since NHTSA does not want to be overly prescriptive for a 
condition that is more representative of its lane keeping test 
scenarios (where lane departure is unintentional and thus turn signal 
engagement is not expected) than its BSW test scenarios (where lane 
departure is deliberate and thus turn signal engagement is likely, 
though not always assured). Although both turn signal use and non-use 
will be represented in the Agency's BSW tests, the Agency's lane 
keeping tests will be conducted without turn signal engagement.
4. Test Conditions for BSI Testing
    In addition to a warning-based blind spot assessment, NHTSA also 
proposed an active safety evaluation (i.e., BSI) for inclusion in NCAP. 
Test scenarios proposed for BSI include two lane change scenarios (SV 
Lane Change with Constant Headway and SV Lane Change with Closing 
Headway) and one false positive scenario (SV Lane Change with Constant 
Headway, False Positive Assessment), to be discussed later.\324\
---------------------------------------------------------------------------

    \324\ While the Agency did not explicitly discuss SAE Driving 
Automation Level 2 and 3 test scenario descriptions for BSI testing 
in its RFC, the proposed test procedures allow for testing of these 
systems. However, the Agency does not anticipate testing Level 2 or 
3 systems as part of NCAP at this time given the limited number of 
applicable vehicles currently available, along with uncertainty 
about the driver and vehicle interaction imposed by such 
implementations.
---------------------------------------------------------------------------

Summary of Comments
    Most respondents to the March 2022 notice did not solely address 
BSI, with comments generally referring to both blind spot technologies 
(i.e., BSW and BSI). However, many commenters did express support for 
inclusion of BSI along with BSW. Aptiv, Consumer Reports, MEMA, ITS, 
Advocates, Bosch, HMNA, NADA, and two individuals, among others, stated 
approval of NHTSA's plan to evaluate BSI as a part of NCAP. Aptiv 
suggested that the proposed parameters would allow NHTSA to quantify 
BSI's benefits. MEMA agreed with NHTSA that all four ADAS technologies 
included as part of this final notice, including BSI, are mature, and 
would not only address a range of crash scenarios, but also offer 
significant safety benefits. In addition, Bosch stated that BSW and BSI 
may both help to reduce the risk of lane-change crashes.
    However, several commenters stated that BSI technology is not 
mature and opposed including it in this NCAP update. GM, Auto 
Innovators, and Honda suggested that BSI could be included in the 
future, particularly once benefits numbers are better established. Auto 
Innovators further clarified that NHTSA should not include the BSI 
evaluation in an ADAS rating but that the group would find it 
acceptable to include it as a recommended technology to encourage BSI 
adoption.
    On the issue of test speeds, Advocates expressed concern that a 
single SV test speed of 72.4 kph (45 mph) would not ensure BSI systems 
operate across an appropriate range of speeds.
Response to Comments and Agency Decisions
    Although some commenters opposed the immediate inclusion of BSI 
into NCAP, many others were in favor of including evaluations for this 
active technology with this program update. NHTSA expects that BSI, in 
tandem with BSW systems, will reduce the frequency of lane-change 
crashes. This is because active safety technologies are thought to be 
more effective than warning technologies alone, so benefit estimates 
for BSI systems should be greater than for BSW systems. As such, it is 
prudent to add BSI technology to NCAP at this time and NHTSA is 
proceeding with adopting all three scenarios proposed for the 
technology in its March 2022 RFC notice--the SV Lane Change with 
Constant Headway scenario, the SV Lane Change with Closing Headway 
scenario, and the SV Lane Change with Constant Headway False Positive 
scenario.
    For the SV Lane Change with Constant Headway Test (shown in Figure 
15), the POV, driven at the same speed of the SV (i.e., 72.4 kph (45 
mph)), is positioned in a lane adjacent to that of the SV with a 
constant longitudinal offset from the rearmost part of the SV, which is 
laterally offset from the center of its travel lane.\325\ After a short 
period of steady-state driving, the SV driver (i.e., robot) will 
initiate a manual \326\ lane change, following an 800 m (2,625 ft.) 
radius curved path towards the POV's travel lane. The SV driver (i.e., 
steering robot) then releases the steering wheel within 250 ms of the 
SV exiting the curve so as to achieve a steady state lateral velocity 
of 0.7  0.1 m/s (2.3  0.3 ft./s) relative to 
the line separating the SV and POV travel lanes. In response to the 
lane change maneuver, the BSI system is expected to intervene and 
prevent the rear of the SV from contacting the front of the POV. 
Additionally, the SV BSI intervention must not cause a secondary 
departure.\327\
---------------------------------------------------------------------------

    \325\ The initial lateral offset of the vehicle from the 
centerline (based on the vehicle width and the desired lateral 
velocity) is to ensure the SV is being operated at the desired 
lateral velocity before BSI operates.
    \326\ ``Manual'' refers to an externally commanded steering 
input. NHTSA will use a steering robot for such inputs to maximize 
accuracy, repeatability, and test efficiency.
    \327\ For the BSI tests, a secondary departure occurs when the 
SV BSI intervention causes the SV to travel 0.3 m (1.0 ft.) or more 
beyond the inboard edge of the lane line separating the SV travel 
lane from the lane adjacent and to the right of it (for lane changes 
to the left) or adjacent and to the left of it (for lane changes to 
the right) within the validity period.
---------------------------------------------------------------------------

    For the SV Lane Change with Closing Headway Test (shown in Figure 
16), the POV, approaching the SV from the rear, is driven at a constant 
speed of 80.5 kph (50 mph). The POV's speed is 8 kph (5 mph) greater 
than that of the SV, which is travelling in an adjacent lane at 72.4 
kph (45 mph), with a lateral offset from center. During the test, the 
SV driver (i.e., steering robot) will initiate a manual lane change, 
following an 800 m (2,625 ft.) radius curved path towards the POV's 
travel lane. The SV driver (i.e., robot) then releases the steering 
wheel within 250 ms of the SV exiting the curve so as to achieve a 
steady state lateral velocity of 0.7  0.1 m/s (2.3  0.3 ft./s) relative to the line separating the SV and POV travel 
lanes. In response to the lane change maneuver, the BSI system is 
expected to intervene and prevent the rear of the SV from contacting 
the front of the POV. Additionally, the SV BSI intervention must not 
cause a secondary departure.
    For the SV Lane Change with Constant Headway, False Positive 
Assessment Test (shown in Figure 17), the POV, driven at 72.4 kph (45 
mph), is positioned in a lane that is two lanes to the left or right of 
the SV's initial travel lane with a constant longitudinal offset from 
the rearmost part of the SV. The SV is laterally offset from the center 
of its travel lane and also travelling at 72.4 kph (45 mph). After a 
short period of steady-state driving, the SV driver (i.e., steering 
robot) will initiate a manual lane change into the adjacent lane (the 
one between the SV and POV) to either the left or to the right. The SV 
follows a defined path toward the adjacent lane, approaching the center 
lane line at a constant lateral velocity of 0.7  0.1 m/s 
(2.3  0.3 ft./s). For this test, the driver (i.e., robot) 
does not release the steering wheel. Since no POV is present in this 
lane and therefore the lane change will not result in an SV-to-POV 
impact, the BSI system must not intervene. To determine whether a BSI 
intervention occurred, the yaw rate data collected for the SV during 
the individual trials are compared to a baseline composite. The 
difference between the data must not exceed 1

[[Page 96033]]

degree/second within the test validity period.
    Assessments for each scenario will be performed during daylight 
conditions only for a POV approach on both the left and right sides of 
the SV (i.e., the SV will make left and right lane changes during 
testing) and with and without the turn signal engaged. Tests will be 
conducted without LCA or cruise control (i.e., conventional or adaptive 
cruise control, or ACC) engaged.
    The Agency notes that of the three BSI test scenarios proposed by 
NHTSA, two closely mirror Euro NCAP's Overtaking Vehicle tests,\328\ 
(SV Lane Change with Constant Headway scenario and SV Lane Change with 
Closing Headway scenario), bolstering support for their adoption into 
U.S. NCAP. Further, NHTSA has found feasible BSI testing according to 
the Agency's draft test procedures. Specifically, in its model year 
2019 and 2020 BSI test series, the Agency found that, while no vehicles 
were able to fully and reliably meet requirements to pass \329\ the SV 
Lane Change with Constant Headway scenario, four of the ten were able 
to pass the SV Lane Change with Closing Headway test. NHTSA expects 
that vehicle performance will improve over time as manufacturers apply 
strategies already in use internationally.
---------------------------------------------------------------------------

    \328\ These tests are specified in Euro NCAP's Lane Support 
Systems (LSS) test protocol as part of its Emergency Lane Keeping 
(ELK) test series.
    \329\ For SAE Driving Automation Level 0- or 1-equipped 
vehicles, a result is considered passing when (1) the SV intervenes 
to avoid contact with the POV during the test and (2) the 
intervention does not cause the SV to travel more than 0.3 m (1.0 
ft.) beyond the inboard edge of the lane line which separates the SV 
travel lane from the one adjacent and to the right of it within the 
validity period. This must be true for any number of trials 
conducted.
---------------------------------------------------------------------------

    The Agency will conduct the adopted BSI test scenarios using the 
72.4 kph (45 mph) SV proposed speed. The SV Lane Change with Closing 
Headway scenario will also retain the 80.5 kph (50 mph) POV speed. The 
rationale for this decision is similar to that provided for BSW--
notably, the speeds' correlation with real-world crash data for 
injurious lane-change crashes and sufficiency for minimum activation of 
blind spot systems. Additionally, these test speeds were developed to 
balance the need to address a real-world safety problem with equipment 
capabilities dictated by the state of technology for the GVT, available 
testing real estate at test laboratories, and the Agency's validation 
efforts (e.g., of the speeds accurately and repeatably attainable with 
the robotic platforms used to move the GVT during BSI test conduct). 
NHTSA concludes that the 72.4/80.5 kph (45/50 mph) test speeds best 
achieve this balance. Additionally, Euro NCAP's Lane Support Systems 
(LSS) protocol for the Emergency Lane Keeping (ELK) Overtaking Vehicle 
test scenarios includes the same SV and POV speeds as those NHTSA has 
specified in its BSI test procedure. Having said this, the Agency 
acknowledges Advocates' concern that a single speed may not address a 
range of real-world driving speeds, and NHTSA may consider testing at 
higher SV/POV speeds in the future. In addition, the Agency may 
reevaluate this decision in the future and adjust the test conditions 
accordingly if real-world crash data shows a need for doing so.
    Although the Agency's draft BSI procedure only specified 
assessments for SV lane changes occurring to the left, the Agency has 
decided to perform BSI testing for a POV approach on both the left and 
right sides of the SV. This is because NHTSA asserts there is reason 
for it to also verify functionality of BSI systems when making a right-
lane change. For example, in real-world cases, the SV may be on a 
multi-lane road or be in the left lane of a two-lane road and 
attempting to move right. As previously mentioned, during the Agency's 
model year 2019 to 2020 BSW research testing, BSW systems appeared to 
perform either the same or worse when the POV approached on the right-
hand side. Thus, symmetrical responses cannot be assumed, and in the 
interest of providing thorough information to the consumer, NHTSA will 
similarly assess both left-hand and right-hand BSI performance. Though 
this addition deviates from Euro NCAP's test protocol, the Agency 
concludes that it is appropriate given the considerations mentioned.
    NHTSA is also adopting ABD GVT Revision G for the POV used in its 
BSI tests, as detailed later in this section. This test device is the 
most suitable vehicle surrogate for BSI testing given its use in NCAP's 
BSI tests would harmonize with the vehicle test device prescribed in 
Euro NCAP's LSS testing protocol for the organization's Overtaking 
Vehicle tests and because it satisfies the specifications defined in 
ISO 19206-3 (2021).\330\
---------------------------------------------------------------------------

    \330\ European New Car Assessment Programme (Euro NCAP) 
(December 2023), Test Protocol--Lane Support Systems, Version 4.3. 
See section 5.
---------------------------------------------------------------------------

    At this time, similar to the decision for the Agency's BSW tests, 
the BSI test scenarios will be conducted during daylight conditions 
only. NHTSA made this decision because, as mentioned previously for 
BSW, 2011-2015 crash data suggests that the majority of lane-change 
crashes (62 percent of fatal lane-change crashes and 76 percent of 
injurious lane-change crashes) occurred annually, on average, during 
daylight hours. The Agency may reevaluate this decision in the future 
and adjust the test conditions accordingly if real-world crash data 
shows a need.
    The same tests must be completed for each vehicle model assessed 
for NCAP to provide equivalent information regarding vehicle 
performance across the fleet. The longitudinal speed of the SV will be 
maintained through manual or robotic control during conduct of NCAP's 
BSI tests. At this time, the Agency will not utilize conventional or 
ACC during NCAP's BSI testing, even though the Agency's draft test 
procedure allows for this flexibility during testing. Since there is no 
vehicle present in the SV forward path, NHTSA does not expect there 
would to be any difference in how the SV's speed is maintained during a 
given BSI test trial if manual/robotic or cruise control is used. 
Cruise control is designed to regulate a vehicle's longitudinal 
movement and therefore should not impact the lateral control 
functionality intrinsic to BSI. However, to ensure fairness across 
testing, it is most appropriate for NCAP to conduct testing utilizing 
only one method of speed control to ensure that the performance of one 
vehicle system (BSI) is not affected in any way by the performance of 
another system (cruise control). NHTSA is choosing to test with manual 
or robotic control in lieu of cruise control since consumers may 
sometimes opt not to use a cruise control feature, particularly on non-
highway roads. NHTSA notes that 55 percent of fatal and 82 percent of 
injurious lane-change crashes, on average, occurred annually between 
2011 and 2015 on roadways that were not considered 
highways.331 332 The Agency will also not use LCA during 
NCAP's BSI tests since not all vehicles are equipped with such 
features.
---------------------------------------------------------------------------

    \331\ Swanson, E., Foderaro, F., Yanagisawa, M., Najm, W. G., & 
Azeredo, P. (2019, August), Statistics of light-vehicle pre-crash 
scenarios based on 2011-2015 national crash data (Report No. DOT HS 
812 745), Washington, DC: National Highway Traffic Safety 
Administration.
    \332\ A highway was defined as such if all three precrash 
trafficway attributes were true: (1) a posted speed limit was >= 45 
mph; (2) the relation to junction was a non-junction, through 
roadway, or other location within an interchange area; and (3) the 
trafficway description was a two-way, divided, unprotected (painted 
> 4 feet) median; two-way, divided, positive median barrier; or 
entrance/exit ramp.
---------------------------------------------------------------------------

    As detailed later in the section, the Agency will nominally perform 
four unique tests for each of the three BSI test scenarios (i.e., with 
the POV on the

[[Page 96034]]

left and right sides of the vehicle and with the SV turn signal engaged 
and disabled). If the SV intervenes and meets the test procedure 
requirements during a trial run, testing will continue until all test 
conditions are assessed. If the SV does not provide an acceptable 
intervention during any trial run conducted for a given test condition, 
BSI testing will cease for the vehicle model. This test methodology is 
appropriate for BSI because it aligns well with that adopted for BSW 
and the other ADAS technologies to be included in NCAP.
    However, in a departure from other ADAS technologies included in 
this notice, NHTSA will assess BSW separately from its active 
technology counterpart (BSI) for NCAP. NCAP has not previously 
evaluated technologies associated with blind spot warning or 
intervention, but assessments for forward collision and lane departure 
warning technologies have been included in NCAP's crash avoidance 
testing since model year 2011. Based on this, it is appropriate to 
allow manufacturers to receive NCAP credit for BSW systems while 
working toward improved BSI performance.
    Finally, in response to Auto Innovators' concern regarding 
inclusion of BSI results in a rating, for this NCAP update, vehicles 
achieving no-contact results (and, in the case of false-positive 
testing, no intervention) and exhibiting no secondary departure, will 
receive a check mark on NHTSA's website. Results will not be combined 
into a rating in the immediate future, but NHTSA may do so at a later 
date.
5. Use of the Turn Signal for BSI
    NHTSA's draft BSI procedure requires utilization of the left turn 
signal during BSI tests, with no instances where the turn signal is not 
enabled in the proposed procedure. NHTSA requested comments on whether 
this is appropriate, and if not, how the Agency could differentiate the 
operation of BSI from the heading adjustments resulting from an LKA 
intervention. NHTSA also asked whether the SV's LKA system should be 
switched off during conduct of the Agency's BSI evaluations.
Summary of Comments
Turn Signal Activation
    Several commenters stated that it is reasonable to perform BSI 
tests with the turn signal enabled. FCA, GM, Honda, Tesla, and Auto 
Innovators responded that BSI tests should be conducted only with the 
turn signal. FCA, Honda, Tesla, and Auto Innovators commented that 
drivers conduct lane changes with intent, so activation of the turn 
signal is appropriate. GM also noted that BSI is reliant on LKA 
functionality and that the use of the turn signal would distinguish BSI 
performance from LKA.
    Toyota, IDIADA, ASC, and ZF Group commented that testing both with 
and without turn signal use would be appropriate. Many of these 
commenters noted that real-world drivers may not signal intent to make 
a maneuver and that the technology should operate regardless of whether 
the turn signal is used. ASC stated that testing in this manner could 
``identify whether there is any difference in operation due to the turn 
signal status.''
    Some commenters, including Rivian, CAS, Aptiv, and one anonymous 
individual, suggested that turn signals should not be used during BSI 
testing. Rivian likened BSI to CIB, stating that ``BSI can be equated 
to collision imminent braking (CIB) in the manner that CIB is the 
elevated interventional stage following forward collision warning 
(FCW).'' Rivian reasoned that turn signal activation should only affect 
warning behavior, not intervention behavior. CAS and an anonymous 
individual noted that, as previously mentioned, drivers may fail to 
signal intent, with CAS stating that ``NHTSA tests should not be based 
on idealized good driving practices but should instead include 
plausible driving errors''. Aptiv further stated that not engaging the 
turn signal is more representative of a real-world driving scenario.
LKA Status if Turn Signal is Off
    The Agency also requested comments on whether LKA should be 
deactivated during BSI evaluations if the turn signal is not used in 
order to differentiate performance between LKA and BSI systems. DRI 
indicated that if the LKA system cannot be turned off the use of the 
turn signal should be required, stating otherwise it would be difficult 
to discern any performance difference. DRI stated it did not have an 
opinion on the matter if the LKA system could be turned off. Honda 
opined that LKA status would not ultimately be relevant as, even if LKA 
were allowed to remain on, BSI would ``take over authority for 
intervention,'' but noted that if LKA was disabled, ``the BSI 
performance will operate more consistently as a BSI system.''
    Toyota, IDIADA, FCA, GM, BMW, and Tesla commented that they 
preferred the LKA system remain enabled while performing BSI tests. 
Toyota, IDIADA, and others also suggested NHTSA should focus on 
technology neutrality, meaning that the test requirements should not 
dictate the technologies needed to meet them. Toyota further stated 
that ``in the real-world condition, both systems may be active and 
function in combination as part of the overall vehicle ADAS features.'' 
Those in favor of keeping the LKA system enabled noted that BSI and LKA 
may be integrated systems that cannot be separated from one another. 
Toyota, BMW, and GM suggested that LKA is likely suppressed in the 
``turn signal on'' condition for some current vehicles.
    Three respondents, Aptiv, Rivian, and one anonymous individual, 
supported the deactivation of LKA during BSI testing. Rivian asserted 
that consumers may turn off LKA due to personal preference and, 
therefore, BSI should be assessed independently. Rivian also stated 
that there will be some interaction between LKA and BSI but that ``the 
OEM should be responsible for determining the detailed interactions and 
communicating their function and interaction to the customer.'' Aptiv 
supported disabling LKA and/or ``auto lane change features'' for 
vehicles equipped with SAE Driving Automation Levels 2 and 3.
    ASC and ZF Group found value in evaluating BSI separately from LKA 
but supported a different approach to differentiate performance. Both 
groups mentioned that LKA may not always be active due to various 
circumstances. Because BSI is proximity-based and not dependent on lane 
markings, both groups suggested that the Agency could avoid activating 
LKA instead of disabling it by testing vehicles on ``a roadway without 
lane markings to differentiate a BSI intervention from an LKS 
intervention.'' Advocates also reasoned that BSI should operate 
independent of lane lines and recommended that the Agency determine 
protocols to test BSI without triggering LKA interventions and vice 
versa.
    Other commenters stated that more research and test development is 
necessary. CAS commented that the ``underlying logic'' for LKA and BSI 
systems is different, so different tests are required. However, CAS 
noted logic differs between vehicle models, so the means to 
discriminate performance of each system may also be different. 
Advocates requested that NHTSA provide its ``research and evaluation of 
vehicles with BSI and LKS systems to justify any decision regarding 
testing protocols.''
Response to Comments and Agency Decisions
    NHTSA will conduct all three BSI test scenarios (i.e., the SV Lane 
Change with

[[Page 96035]]

Constant Headway scenario, the SV Lane Change with Closing Headway 
scenario, and the SV Lane Change with Constant Headway False Positive 
scenario) two times for each POV approach direction (left and right)--
once with the turn signal engaged and once without use of the turn 
signal. Assessments will be performed with the vehicle's LKA system 
`off' if the LKA system can be disengaged and its LCA system `off' if 
the vehicle is so equipped.
    The Agency agrees with commenters who stated that turn signal use 
during NCAP's BSI test is appropriate; the related test scenarios 
represent situations where drivers intend to conduct a lane change. 
NHTSA also agrees with GM that use of the turn signal in the Agency's 
BSI tests serves to distinguish BSI performance from that of LKA. 
NHTSA's LKA tests are designed to represent unintentional lane 
departures, and as such, the turn signal is not engaged. However, as 
mentioned for BSW, there is merit to the assertion from other 
commenters that drivers often fail to outwardly signal intent to make a 
lane change by engaging their turn signal. Both use and non-use of the 
turn signal can represent intentional lane departure situations during 
real-world driving. By omitting the latter, the Agency would fail to 
capture a significant portion of use cases in the real world. Rivian's 
point that turn signal activation may affect whether the vehicle warns 
the driver but not whether it intervenes once the driver begins to 
perform a lane change is also valid. Once the lane change maneuver has 
begun, the driver's intent is known, regardless of whether the driver 
activated the turn signal indicator, and the vehicle's BSI system 
should respond accordingly. Given this, the Agency would be remiss to 
only evaluate a BSI system's ability to intervene in situations where 
the driver has utilized their turn signal. As several respondents 
suggested, NHTSA must also assess system functionality when the turn 
signal is not used prior to a lane change maneuver.
    NHTSA will perform all BSI assessments for a vehicle (i.e., both 
those conducted with the turn signal activated and those conducted 
without) with the LKA system `off' if the LKA system can be disengaged. 
LKA systems provide brief heading corrections needed to bring a vehicle 
away from a lane line after it has been crossed or if a crossing has 
been deemed imminent. Although the Agency recognizes that several 
respondents recommended that the LKA system remain enabled while 
performing BSI tests to promote technology neutrality, NHTSA asserts 
that setting the LKA system to `off' is more appropriate. A vehicle's 
LKA system is not guaranteed to be `on' during real-world driving. 
While it is true that BSI and LKA systems may both be active and 
function in combination during real-world driving as Toyota asserted, 
it is also possible that consumers may turn off LKA due to personal 
preference, as Rivian contended. Further, as noted in the March 2022 
RFC, NHTSA is aware of studies which suggest that drivers frequently 
disable lane departure technologies.\333\ Accordingly, assessing BSI 
functionality independent of LKA functionality during NCAP's BSI tests 
seems appropriate.
---------------------------------------------------------------------------

    \333\ 87 FR 13461.
---------------------------------------------------------------------------

    Although DRI recommended that turn signal use should be required 
for any tests conducted for vehicles in which the LKA system cannot be 
turned off to discern performance differences between a vehicle's BSI 
and LKA systems, it is still appropriate to perform assessments both 
with and without turn signal engagement in such instances. As 
mentioned, not all drivers utilize the turn signal indicator when 
changing lanes. As Honda opined, BSI should resume intervention 
authority even if the LKA system remains `on' for testing. If a 
vehicle's LKA system were to affect BSI performance for fully-
integrated LKA and BSI systems, any influence should be representative 
of real-world driving circumstances. As such, it is appropriate to 
still include an evaluation requiring that the turn signal not be 
activated for those vehicles where the LKA system cannot be turned 
`off.'
    NHTSA will not test vehicles on a roadway without lane markings to 
differentiate BSI and LKA interventions without deactivating LKA, as 
suggested by several commenters. Since most multiple lane roads 
conducive to lane changes on which vehicles will be travelling at the 
speeds to be assessed will have lane lines, conducting BSI tests on 
roadways devoid of lane markings would not be representative of real-
world driving conditions. Further, while lane markings may not 
influence BSI performance for vehicles with LKA systems that can be 
switched off, the Agency reasons a lack of lane markings may affect 
both LKA and BSI system functionality (and thus BSI performance) for 
those vehicles with fully integrated BSI and LKA systems where LKA 
cannot be deactivated for BSI testing. This assumption is bolstered by 
GM's assertion that BSI is reliant on LKA functionality.
    Finally, as previously mentioned, the Agency will set a vehicle's 
LCA system, which serves to continuously provide steering inputs needed 
to keep a vehicle centered in its lane of travel, to `off' (if 
equipped) for all BSI tests.
6. User-Configurable Settings for BSW and BSI Tests
    For NHTSA's BSW and BSI testing, the Agency will set the timing for 
the warning in BSW systems and intervention in BSI systems to the 
middle (or next latest) setting (if adjustable) during its BSW/BSI 
evaluations, similar to that previously shown in Figure 2 for FCW 
evaluations. For BSW and BSI systems having only two settings, the 
Agency will select the later of the two settings and this test setting 
will meet NHTSA's middle (or next latest) BSW/BSI setting requirement. 
These system setting configurations align with Euro NCAP's LSS test 
protocol.
    All BSW and BSI tests will also be conducted with LKA and cruise 
control (i.e., conventional or adaptive cruise control, or ACC) `off' 
if such systems can be disengaged. Lane centering functions will also 
be set to `Off' for all BSW and BSI tests in alignment with Euro NCAP's 
LSS test protocol.
7. BSI False Positive Testing
    NHTSA proposed including a false positive test (SV Lane Change with 
Constant Headway, False Positive Assessment Test) in its BSI test 
procedure to evaluate the propensity of the system to inappropriately 
activate in a situation that does not pose a crash risk to those in the 
SV.
Summary of Comments
    Commenters expressed mixed opinions for this proposed test 
scenario. Some, including TRC, CAS, Advocates, ZF Group, Vayyar, Intel, 
Rivian, and one anonymous individual, commented that a false positive 
test scenario is a valuable testing inclusion. Many commenters, 
including CAS, Advocates, ZF Group, Vayyar, Rivian, and CR, conveyed 
that false positive activations could cause customer dissatisfaction, 
leading to customers ignoring or deactivating the technology. TRC 
commented that to maximize the benefit of a technology, NHTSA must 
encourage maximum consumer confidence and use. Advocates mentioned this 
is particularly important for active technologies in which the driver 
cannot ignore a false positive activation. CAS and Vayyar noted that 
inappropriate activation may cause undesirable driver reactions, 
leading to potentially dangerous driving behavior.

[[Page 96036]]

    Other commenters stated that the false positive testing scenario is 
not appropriate or necessary for NCAP. Auto Innovators and Toyota 
stated that false positive activations are difficult to reproduce 
because of situational complexity and suggested that a limited number 
of test runs cannot determine the overall robustness of the system. FCA 
did not oppose the inclusion of a false positive test scenario but 
reasoned that it may be difficult to determine a concise test 
methodology. Toyota and others stated that manufacturers may begin 
designing their systems to pass tests instead of performing acceptably 
in real-world conditions.
    As discussed in the AEB and PAEB sections, manufacturers commented 
that they are strongly motivated to design robust systems that do not 
falsely activate because they have a vested interest in maximizing 
consumer satisfaction. FCA responded that manufacturers will discover 
excessive false-positive activations through customer complaints and 
quality metrics. Likewise, GM noted that, due to the myriad of 
situations that may trigger a nuisance activation, the automaker would 
find these customer quality metrics and field data reports to be more 
useful. Rivian and BMW shared that manufacturers often already conduct 
in-house false positive testing to ensure customer acceptance, and 
Toyota stated that manufacturers must take the consumer's satisfaction 
into account when balancing true positive cases with true negative and 
false positive cases. Honda and Auto Innovators noted that BSW systems 
have high consumer satisfaction without the need for a false positive 
test, and both groups stated they expect that BSI systems will also be 
accepted similarly.
    BMW indicated that because of the work already completed on 
eliminating false positives by manufacturers, there would be little 
benefit to adding a false positive scenario to NCAP's testing regimen. 
The automaker further stated that performing a small number of tests to 
mitigate false activations would not adequately address the variety of 
driving conditions that a driver may experience and would not be 
commensurate with the amount of test effort needed. Bosch noted that 
specialized infrastructure and equipment may be needed to conduct false 
positive test scenario runs, adding unnecessary test burden and 
complexity.
    Tesla and Auto Innovators mentioned that the reduction of false 
positives may also come at the cost of increased false negatives, and 
HATCI suggested that false positive testing could lead to unintended 
consequences that may impact future technologies. HATCI recommended 
that NHTSA focus on test scenarios that represent safety needs from the 
field, particularly ones that address fatal and injurious crashes. 
Tesla commented that the greatest safety benefits will be realized when 
false negatives are minimized, adding that vehicle manufacturers may 
add other countermeasures to further mitigate false positives.
    In relation to the false positive test procedure itself, DRI 
proposed that false positive scenarios do not require the full set of 
test runs specified for baseline tests and stated that no more than 
three would be necessary. Additionally, Vayyar noted the importance of 
including typical surroundings and static objects like fences, parked 
cars, trees, etc. ASC echoed this sentiment, commenting that NHTSA 
should consider what objects or scenarios may trigger false activations 
when developing and selecting test procedures for NCAP. As an example, 
ASC stated that BSI systems may falsely activate in response to 
oncoming traffic in the adjacent lane or stationary objects.
Response to Comments and Agency Decisions
    The Agency is retaining the SV Lane Change with Constant Headway, 
False Positive Assessment test scenario currently included in its BSI 
test procedure. As mentioned, the objective of this test scenario is to 
assess whether the BSI system detects and responds to a non-threatening 
POV during a single lane change. The Agency's decision is consistent 
with the decision made by the Agency for AEB and aligns with the 
comments received by many, though not all, respondents.
    In response to the Agency's March 2022 RFC notice, vehicle 
manufacturers reiterated similar comments to those submitted in 
response to the Agency's false positive AEB tests. Most notably, they 
maintained that false positive tests in NCAP should be unnecessary 
because automakers have an inherent interest in designing robust 
systems and limiting false activations to maintain high customer 
satisfaction. Several manufacturers asserted that excessive false 
activations would be realized through quality metrics and/or customer 
complaints or through internal testing. However, if a manufacturer's 
efforts were sufficient to eliminate false positive activations, such 
incidents would not be observed by manufacturers in field data reports. 
Further, while BMW contended there would be little benefit to adding a 
false positive scenario to the matrix because of manufacturer efforts 
to date to eliminate false positive activations for blind spot 
technologies, NHTSA questions this rationale. Only 38 percent of model 
year 2024 vehicles are currently equipped with BSI technology. As such, 
acceptable false positive rates for yet-to-be-designed BSI systems for 
the majority of the vehicle fleet cannot be intrinsically assumed. 
NHTSA also rejects Toyota's assertion that incorporating a false 
positive test for BSI would encourage manufacturers to design systems 
solely to pass the Agency's tests, rather than to perform well during 
real-world driving, as acting in such a manner would seemingly conflict 
with automakers' assertions of performing due diligence and assuring 
customer satisfaction. Further, the test conditions for the SV Lane 
Change with Constant Headway, False Positive Assessment test are not 
obscure. As such, NHTSA does not foresee that a vehicle will achieve 
good BSI false positive assessment performance as a direct result of 
compromised operation in other real-world driving situations. Based on 
these considerations, adopting a false positive test for NCAP's BSI 
test matrix is appropriate and can be incorporated without an 
associated increase in false negatives or other unintended 
consequences, as expressed by some commenters.
    The Agency also agrees with those commenters who supported the 
inclusion of a false positive BSI test and suggested that NHTSA should 
discourage false positive activations, encourage system use, and ensure 
consumer confidence in blind spot technology. Any false positive 
activation may cause drivers to respond with irresponsible driving 
behavior, as CAS and Vayyar suggested, or cause general customer 
dissatisfaction, potentially leading to deactivation of the technology. 
Advocates' assertion that maintaining a high level of customer 
satisfaction is especially important for active technologies since a 
system's intervention cannot simply be ignored by the driver is valid. 
Though Honda and Auto Innovators suggested that, since BSW systems 
currently have a high rate of customer satisfaction without an 
associated false positive test, so too should BSI systems, the Agency 
does not agree with this deduction. Rather, adopting a false positive 
test for NCAP's BSI test matrix will help ensure sensor robustness and 
thereby maintain or improve overall consumer sentiment pertaining to 
blind spot technology.
    The Agency maintains this position while also acknowledging that 
the proposed false positive test is neither

[[Page 96037]]

comprehensive enough nor adequate to eliminate susceptibility to all 
false activations, as BMW and GM asserted. NHTSA acknowledges that a 
myriad of situations may trigger a false positive system response 
during real-world driving. It is also true, as Toyota and Auto 
Innovators contended, that one test may not sufficiently gauge overall 
system robustness. However, NHTSA reasons that its SV Lane Change with 
Constant Headway, False Positive Assessment test serves to provide a 
baseline for BSI system functionality and establish a minimum expected 
performance level. If the test provides even limited coverage of real-
world lane change/merge conditions, it will afford additional safety, 
and is thus advantageous to include for NCAP's BSI evaluations.
    Several commenters suggested that false positive tests are 
inherently difficult to conduct (Auto Innovators and Toyota) or require 
specialized infrastructure and equipment (Bosch). However, this is not 
the case for the Agency's SV Lane Change with Constant Headway, False 
Positive Assessment test. This test, which requires that the SV perform 
a single lane change into an adjacent lane while the POV is driven 
straight, is relatively easy to conduct and has been performed 
successfully as part of NHTSA's research test program. It imposes no 
additional complexity or test burden compared to the other BSI tests 
included in the Agency's test protocol, other than the additional three 
baseline runs necessary for each test condition that must be conducted 
to assess BSI system performance. NHTSA recognizes that DRI suggested 
it was necessary to perform only three baseline runs for the false 
positive test scenario (i.e., three baseline runs for each test 
condition), and the Agency agrees, since the Agency's research testing 
has shown three baseline runs to be sufficient and this should keep 
test burden to a minimum.
    At this time, NHTSA will not require placement of additional static 
objects within the test environment for its BSI assessments, as Vayyar 
and ASC requested. As previously mentioned, the Agency's false positive 
BSI test is intended to serve to judge a level of minimum acceptable 
performance. It is not expected to address the numerous potential lane 
change/merge driving situations that may invoke a false positive 
intervention. Additionally, as BSI will be a newly adopted technology 
for NCAP, it is currently more important to encourage technology 
adoption across a larger segment of the vehicle fleet rather than the 
adoption of overly burdensome requirements. The Agency has also not 
conducted research to assess the impact of such objects on system 
performance, and it would therefore be premature to incorporate these 
items in test scenarios adopted for this NCAP upgrade.
    Although static objects and oncoming vehicles will not be part of 
the Agency's initial BSI assessments, NHTSA expects that vehicle 
manufacturers should design BSI systems to address the potential for 
false activations in all possible real-world situations so that 
vehicles do not pose an unreasonable risk to safety. Given the comments 
received, this expectation aligns with steps already being taken by 
automakers to ensure customer satisfaction. Similar to the plan 
discussed for AEB, NHTSA will continue to monitor customer complaints 
to look for reports of frequent false activations for BSI systems as 
part of its defects identification and investigation process. The 
Agency also has the authority to investigate whether vehicles 
experiencing excessive false positive activations have a safety-related 
defect since they may pose an unreasonable risk to safety. NHTSA will 
continue to handle such cases appropriately as they arise. The Agency 
may also consider adding other false positive tests to NCAP in the 
future to capture additional driving situations if real-world data 
suggests a safety need exists.
8. Use of the ABD GVT Revision G for BSI Testing
    A real vehicle is currently utilized in the Agency's BSW test 
procedure. However, in the March 2022 RFC, NHTSA detailed its intent to 
use the [ABD] GVT Revision G in its BSI test procedure as the vehicle 
test device. As previously discussed in the AEB section, the ABD GVT 
Revision G vehicle test device includes minor changes to its shape and 
radar characteristics to more closely approximate an actual vehicle. 
Its use in NCAP's BSI test would further promote global harmonization 
since the GVT is used in Euro NCAP's Lane Support Systems testing 
protocol.\334\ NHTSA used the ABD GVT Revision G in its pilot testing 
series.
---------------------------------------------------------------------------

    \334\ European New Car Assessment Programme (Euro NCAP) 
(December 2023), Test Protocol--Lane Support Systems, Version 4.3. 
See section 5.
---------------------------------------------------------------------------

Summary of Comments
    Most commenters remarking on this topic agreed the [ABD] GVT 
Revision G is the most appropriate strikeable vehicle test device for 
use in BSI testing. MEMA, FCA, Bosch, Honda, Auto Innovators, Toyota, 
ASC, ZF Group, Rivian, BMW, HATCI, Tesla, Intel, and GM were all in 
favor. The use of a standardized vehicle test device was a motivating 
factor for nearly all commenters who indicated approval (Auto 
Innovators, Toyota, ASC, ZF Group, BMW, HATCI, Tesla, and Intel). Auto 
Innovators also commented that the use of the [ABD] GVT Revision G for 
BSI testing would reduce test burden for manufacturers and laboratories 
since the same vehicle test device could be used for CIB and DBS. Bosch 
noted the [ABD] GVT Revision G's improved side strength and radar 
characteristics.
    However, GM preferred the ``most representative test target that 
can safely be used in all intended test scenarios,'' meaning that if 
there is low risk of POV-to-SV contact, a real vehicle would be more 
desirable. For more aggressive BSI scenarios, GM agreed that the use of 
the [ABD] GVT Revision G is appropriate. Advocates remarked that NHTSA 
should justify any aspect of the test procedures, including the 
strikeable vehicle test device used, through presentation of testing 
and data analyses. Bosch also requested that NHTSA refer to a standard 
\335\ rather than a specific product in its test procedures to give 
more flexibility to those implementing tests. Should there be any 
changes to the ABD GVT Revision G, HATCI requested that the Agency 
provide a chance to review the changes with sufficient lead time to 
understand the impact that such changes may have on its product design.
---------------------------------------------------------------------------

    \335\ ISO 19206-3:2021.
---------------------------------------------------------------------------

    With respect to logistical concerns, TRC questioned whether NHTSA 
would find it acceptable to retrofit an [ABD] GVT Revision F soft car 
(or other) with a kit to bring it in line with Revision G 
specifications. It also noted that minor impacts with the vehicle test 
device may interfere with vehicle kinematics at the higher test speeds 
specified in the proposed procedure. For this reason, the laboratory 
asked whether the Agency would require contact to determine performance 
or if a tight tolerance for no contact may be used instead, citing a 
desire to reduce test burden.
Response to Comments and Agency Decisions
    Based on the comments received, NHTSA has decided to use the ABD 
Revision G GVT for NCAP's BSI tests at this time. Adopting this test 
device for NCAP's BSI tests should minimize burden for manufacturers 
since the same test device will be prescribed in the Agency's AEB test 
protocol and is approved for use in Euro NCAP's LSS

[[Page 96038]]

and AEB test protocol evaluations.\336\ In addition, the ABD GVT 
Revision G was found to be robust and durable in the Agency's most 
recent BSI research tests. Further, ABD has indicated this test device 
complies with ISO 19206-3:2021, ``Road vehicles--Test devices for 
target vehicles, vulnerable road users and other objects, for 
assessment of active safety functions--Part 3: Requirements for 
passenger vehicle 3D targets'' \337\ with respect to the specifications 
outlined for radar cross section, reflectivity, color, and physical 
dimensions. Therefore, the Agency considers it an acceptable surrogate 
of a real vehicle and appropriate for use in NCAP's BSI assessments.
---------------------------------------------------------------------------

    \336\ https://www.euroncap.com/en/for-engineers/supporting-information/technical-bulletins/. See Appendices I & II.
    \337\ https://www.iso.org/standard/70133.html. May 2021.
---------------------------------------------------------------------------

    Specifying a standardized vehicle test device is appropriate, as 
doing so should promote fairness and ensure repeatability and 
reproducibility of test results. That being said, the Agency also 
recognizes, as Bosch mentioned, that stipulating a standard the BSI 
vehicle test device must comply with instead of designating a specific 
device for use will afford more flexibility to those conducting BSI 
tests. While there are benefits to such an approach, NHTSA has not 
conducted thorough evaluations of alternative test devices that also 
meet the ISO specifications, such as the 4a GVT, to ensure they invoke 
equivalent vehicle/system performance as the ABD GVT Revision G in the 
Agency's BSI tests. Therefore, at this time, the Agency is specifying 
use of the ABD GVT Revision G in NCAP's BSI tests to mitigate 
variability between the Agency's official test results and those 
submitted by the vehicle manufacturer.
    The Agency notes that while it allows use of a real vehicle during 
its BSW testing, this is not an appropriate approach for its BSI 
testing. This is because for NHTSA's BSI tests (with the exception of 
the false positive test scenario), the SV initiates a manual lane 
change into the POV's travel lane. Because of this lane change 
maneuver, contact between the SV and POV is possible. On the other 
hand, SV movement in NHTSA's BSW tests is confined to a pass-by 
maneuver, where both the SV and POV maintain their position within 
their respective lanes, or a converge/diverge maneuver, where the POV 
performs a lane change into a lane that is adjacent to the SV but not 
in the same lane as the SV. Consequently, the ABD GVT Revision G, not a 
real vehicle, is appropriate for NCAP's BSI testing so tests can be 
conducted safely. While the Agency will permit use of a real vehicle in 
NCAP's BSW tests, it is also amending the test procedure to allow use 
of the ABD GVT Revision G in those test scenarios. Further, since the 
BSI false positive test should not result in contact, the Agency's test 
procedure will permit use of a real vehicle for that test scenario.
    Along these lines, NHTSA will not alter the no contact evaluation 
criterion currently included in the Agency's BSI test procedure to 
permit a tolerance, as TRC requested. Contact was observed during 
numerous trials conducted as part of the Agency's BSI research testing 
and vehicle kinematics post-contact did not generate concern for the 
safety of laboratory personnel or create additional test burden.
    Although NHTSA will use the ABD Revision G GVT in its official BSI 
testing and will not accept manufacturer test data for BSI assessments 
performed utilizing alternative test devices at this time, 
manufacturers may choose to utilize ABD GVT Revision F, as TRC 
requested, when performing tests for NCAP data submission, if it is 
retrofitted with a kit to ensure it meets the specifications for 
Revision G. Such adaptations are necessary because ABD GVT Revision G 
includes changes to the front and sides when compared with Revision F, 
specifically to permit improved side strength and radar 
characteristics. Any revision of the ABD GVT utilized for BSI testing, 
whether Revision G or Revision F that has been retrofitted to be 
equivalent to Revision G, must also meet all specifications and 
requirements outlined herein as well as those prescribed in NHTSA's BSI 
test procedure.
    With regards to HATCI's concerns pertaining to version control of 
the vehicle test device, the Agency will be as transparent as possible 
about any potential changes to test equipment used for its BSI 
performance evaluations in the future.
Vehicle Test Device Specifications
    Even though it is not necessary to prescribe all specifications for 
the ABD GVT Revision G for NCAP testing, since compliance with the ISO 
standard should be inherent, the Agency is nonetheless referencing ISO 
19206-3:2021 in NCAP's BSI test procedures, as it did for NCAP's AEB 
tests. This should ensure any device utilized for Agency testing 
complies with the standard's specifications.
9. Number of Trials and Pass Rate
    As with the other ADAS technologies proposed, the Agency's proposed 
BSW and BSI test procedures included multiple trial runs for each given 
test scenario. The proposed BSW test procedure required seven repeated 
trials for each test condition (i.e., left and right POV approach 
direction) assessed for a scenario (14 tests overall for Straight Lane 
Converge and Diverge and 56 tests overall for Straight Lane Pass-by). 
The number of proposed trials for the BSI procedure depended upon the 
test scenario to be performed. Seven repeated trials were specified for 
the SV Lane Change with Constant Headway test and the SV Lane Change 
with Closing Headway test, while three repeated trials were prescribed 
for the SV Lane Change with Constant Headway, False Positive Assessment 
Evaluation test. NHTSA requested comments on the appropriate number of 
trials required for each adopted test condition and the appropriate 
pass rate for BSW and BSI tests. The Agency proposed that a vehicle 
would have to pass five out of seven trials for a given BSW test 
condition to receive credit for the technology; however, no pass rate 
was proposed for BSI systems.
Summary of Comments
Number of Trials
    Several commenters provided input suggesting the number of trials 
for BSW could be reduced from what NHTSA proposed. TRC, GM, IDIADA, 
Rivian, Auto Innovators, Tesla, and Bosch opined that fewer than seven 
trials are needed. Those in favor of trial run reduction mentioned 
there is consistency in vehicle alert times (TRC) and limited variance 
in test results. TRC, GM, and Rivian were in favor of reducing the 
number of trial runs to five, while Bosch and Tesla recommended 
reducing the number to three trials. Tesla stated that three trials are 
needed for BSW because it is a warning system only and does not 
intervene, with the driver maintaining control of the vehicle. IDIADA 
recommended reducing to just one trial run, citing relevant experience 
in LKA and AEB testing. However, it also stated that the BSW pass-by 
test is simple and subsequent trials can be performed easily if 
desired. Toyota and Auto Innovators suggested a reduction to either 
three or five trials to alleviate test burden. Like others, Intel 
suggested that NHTSA seek to reduce unnecessary test burden, but the 
company did not offer a specific number of trial runs that should be 
included.
    TRC made the recommendation to perform five trial runs for both BSW 
and BSI. The laboratory asserted that the battery life of the GVT 
robotic platform

[[Page 96039]]

can become problematic, and thus, a decrease in the number of test runs 
could preserve the platform's battery and eliminate some invalid runs. 
Rivian also recommended that NHTSA reduce the procedural requirement 
for BSI to five trial runs. On the other hand, Tesla recommended 
running seven BSI trials per test condition. While the automaker 
expressed support for reducing the number of BSW trial runs, it did not 
support a reduction for BSI tests because the system controls the 
vehicle on the driver's behalf. Tesla reasoned that NHTSA should more 
rigorously evaluate any vehicle interventions not initiated by the 
driver.
    Other commenters stated that seven trial runs are appropriate for 
BSW. Honda, FCA, ASC, BMW, and ZF Group supported NHTSA's proposal for 
seven trials. The main reason cited for keeping the trial run count the 
same was maintaining consistency with existing test procedures. It 
should be noted that, while GM and Auto Innovators were in favor of 
reducing the number of trial runs per condition, both groups were also 
not opposed to maintaining seven trial runs. GM mentioned maintaining 
consistency amongst different test types and asked the Agency to 
consider that additional trial runs in the same test scenario are not 
as labor-intensive as changing the test setup to a different test 
scenario. GM therefore requested NHTSA optimize the number of test 
scenarios rather than focus on the number of test runs.
    Advocates and CAS opined there must be additional evidence provided 
to determine the appropriate number of test runs. Advocates stated that 
NHTSA should provide evidence that the number of trials selected will 
ensure that vehicles identified with the technology will operate as 
intended for the life of the vehicle. Similar to its requests for the 
other technologies NHTSA proposed for adoption in NCAP, CAS requested 
that the Agency use a statistical analysis to determine an appropriate 
number of trials to ensure system robustness.
Pass Rate
    Many commenters suggesting that seven BSW trials should be 
conducted held the view that five of seven tests should be required to 
pass to gain BSW system credit. Honda, GM, FCA, ASC, BMW, and ZF Group 
expressed that requiring five of seven tests to pass is reasonable, 
offers credit to systems which will effectively mitigate real-world 
crashes, and maintains consistency with existing ADAS test procedures. 
Although Auto Innovators expressed a preference for fewer trial runs 
per condition, should NHTSA continue with seven runs, the group 
recommended the Agency require five of seven runs to pass. Auto 
Innovators opined that if the first five runs pass, then the vehicle 
should be considered as passing and testing should be discontinued to 
reduce unnecessary test runs.
    Commenters recommending five trials often suggested that three of 
five should pass (Toyota, GM, and Auto Innovators). For those 
recommending three trials, most often commenters requested that two of 
the three trial runs pass. Toyota noted that one failed trial should be 
permitted to prevent a vehicle from being misclassified because of a 
one-off occurrence. The automaker stated that this follows other crash 
avoidance NCAP test methodology. Some commenters stated NHTSA should 
not permit any failed runs. However, IDIADA stated one test per 
condition should be sufficient, and vehicles should be expected to pass 
since test data does not show wide variation.
    Rivian and Tesla commented that pass rate should depend on the 
nature of the system evaluated, with both automakers stating that 
systems that deliver information (i.e., BSW) should be expected to pass 
100 percent of the tests conducted. Both also asserted that systems 
which intervene to control the vehicle movement (i.e., BSI) should have 
a pass rate based on the nature of technology. Rivian stated that NHTSA 
should ``take into account external and internal variables'' and 
determine an appropriate pass rate based on this fact. Rivian stated it 
did not approve of binary pass/fail criteria for BSI but did not 
provide a suggested pass rate. Tesla recommended that five out of seven 
BSI trials per condition pass.
    Like the feedback received on the number of trials mentioned in the 
previous section, Advocates and CAS suggested that pass rates should be 
based on additional information and evidence.
Response to Comments and Agency Decisions
Number of Trials for BSW
    The Agency has determined that it will conduct one trial per test 
condition to ensure BSW system performance affords the consistency that 
consumers expect and safety demands. This finalized testing methodology 
is akin to that of AEB and PAEB testing.
    NHTSA does not agree with Tesla's assertion that warning systems do 
not require the same level of rigor when they are assessed for NCAP. To 
maintain the credibility of the consumer information provided to the 
public, all ADAS technologies, whether warning-based or active safety 
features, should be proven reliable in the test conditions assessed 
before they are given credit for passing NCAP's testing. NHTSA 
maintains, as it has done elsewhere in this notice, that the best way 
to ensure system reliability is not to perform repeated test trials. 
Repeated trials inherently permit a certain threshold of failures, and 
failures of any number are unacceptable under the limited, ideal test 
conditions to be assessed. As such, the Agency will perform a single 
trial for each test condition to assess BSW system performance. This 
decision aligns with assertions from those commenters who suggested 
that fewer BSW trials could be conducted than were proposed initially 
and maintains congruity amongst NCAP's ADAS testing protocols, as 
multiple commenters requested.
    For the Straight Lane Converge and Diverge test scenario, NHTSA 
will perform one trial for each test condition (i.e., POV approach 
directions of right and left, each with turn signals enabled and 
disabled), resulting in four Straight Lane Converge and Diverge test 
trials total. For its BSW Straight Lane Pass-by testing, NHTSA will 
conduct one trial per each speed differential, POV approach side, and 
turn signal status combination for a total of 16 Straight Lane Pass-by 
trials per vehicle model assessed. Despite GM's concern that changing 
the test setup is more difficult than simply running multiple trials 
for one scenario, this testing methodology should balance test burden 
with the Agency's need to thoroughly evaluate BSW system performance. 
It should also limit damage to the test vehicle, vehicle test device, 
and equipment, and best ensure the safety of laboratory personnel.
    Considering all BSW testing adopted in this notice, each vehicle 
model assessed for BSW system performance will undergo 20 trials total, 
a significant reduction from the 70 initially proposed by NHTSA. This 
reduction in the number of trials should address Toyota's concern 
regarding timely release of information to consumers.
Number of Trials for BSI
    In the interest of test consistency, reduced testing burden, and 
ensuring system reliability, NHTSA will also apply the same one-trial 
test methodology to all three BSI assessment scenarios for NCAP: (1) SV 
Lane Change with Constant Headway, (2) SV Lane Change with Closing 
Headway, and (3) SV Lane Change with Constant Headway, False Positive 
Assessment.

[[Page 96040]]

    Although Tesla suggested that NHTSA conduct seven trials for each 
BSI scenario because the vehicle intervenes on the driver's behalf, 
test burden and logistical considerations are also factors that must be 
considered. With one trial required for each assessment condition 
(i.e., POV approach directions of right and left, each with turn 
signals enabled and disabled), a vehicle model will undergo 12 trials 
for BSI testing overall. Given TRC's concern that the GVT's robotic 
platform has a limited battery life, which may serve to reduce testing 
efficiency and delay the release of information to the public, NHTSA 
does not wish to impart additional burden and delay for what it 
concludes to be limited benefit. In addition, since other ADAS 
technologies will no longer undergo seven trials, NHTSA reasons that a 
reduction in trials for BSI testing will best maintain consistency with 
other test procedures, a request expressed by several commenters. 
Proceeding with one trial per test condition will also best ensure 
performance consistency and safety benefits.
Pass Rate
    The pass rate for all adopted BSW and BSI testing (i.e., 20 
required tests to obtain credit for BSW and 12 required tests to obtain 
credit for BSI) will be 100 percent. No test failures will be permitted 
during any of the BSW or BSI trials conducted for NCAP.
    NHTSA acknowledges that some commenters suggested BSW and BSI test 
pass rates should be treated differently because one is a warning 
technology only and the other is active. However, NHTSA disagrees with 
this assessment. As mentioned previously, the Agency reasons its 
assessment of performance should be handled with the same stringency 
whether a technology is an active technology or simply meant to provide 
information to the consumer.
    Tests that NHTSA is adopting for BSW and BSI testing are shown in 
Tables 23 and 24.

                           Table 23--Blind Spot Warning (BSW) Adopted Test Conditions
----------------------------------------------------------------------------------------------------------------
                                   SV speed (kph  POV speed (kph     POV direction of
          Test scenario               (mph))          (mph))             approach               Turn signal
----------------------------------------------------------------------------------------------------------------
Straight Lane Converge and             72.4 (45)       72.4 (45)  Right.................  Enabled.
 Diverge.                                                                                 Disabled.
                                                                  Left..................  Enabled.
                                                                                          Disabled.
Straight Lane Pass-by...........       72.4 (45)       80.5 (50)  Right.................  Enabled.
                                                                                          Disabled.
                                                                  Left..................  Enabled.
                                                                                          Disabled.
                                                       88.5 (55)  Right.................  Enabled.
                                                                                          Disabled.
                                                                  Left..................  Enabled.
                                                                                          Disabled.
                                                       96.6 (60)  Right.................  Enabled.
                                                                                          Disabled.
                                                                  Left..................  Enabled.
                                                                                          Disabled.
                                                      104.6 (65)  Right.................  Enabled.
                                                                                          Disabled.
                                                                  Left..................  Enabled.
                                                                                          Disabled.
----------------------------------------------------------------------------------------------------------------


                         Table 24--Blind Spot Intervention (BSI) Adopted Test Conditions
----------------------------------------------------------------------------------------------------------------
                                   SV speed (kph  POV speed (kph
          Test scenario               (mph))          (mph))       Lane change direction        Turn signal
----------------------------------------------------------------------------------------------------------------
SV Lane Change with Constant           72.4 (45)       72.4 (45)  Left..................  Enabled.
 Headway.                                                                                 Disabled.
                                                                  Right.................  Enabled.
                                                                                          Disabled.
SV Lane Change with Closing            72.4 (45)       80.5 (50)  Left..................  Enabled.
 Headway.                                                                                 Disabled.
                                                                  Right.................  Enabled.
                                                                                          Disabled.
SV Lane Change with Constant           72.4 (45)       72.4 (45)  Left..................  Enabled.
 Headway, False Positive                                                                  Disabled.
 Assessment.
                                                                  Right.................  Enabled.
                                                                                          Disabled.
----------------------------------------------------------------------------------------------------------------

10. Test Procedure Refinements
    Several commenters provided suggestions for specific test procedure 
refinements in response to the March 2022 RFC notice. The Agency 
provides responses to these comments in the following section.
    NHTSA also published and requested comment on draft BSW and BSI 
test procedures in November 2019. The Agency received feedback from the 
public at that time, some of which was referenced again in comments to 
the March 2022 RFC notice. Updated BSW and BSI test procedures 
reflecting the Agency's response to the comments received will be 
published separately in conjunction with this notice in the related 
docket.

[[Page 96041]]

Summary of Comments
    Harmonization was a common underlying theme in the comments 
received to the Agency's March 2022 RFC notice. Aptiv encouraged NHTSA 
to align its blind spot test procedures with the BSW and BSI content 
within Euro NCAP's Lane Support System protocol to the greatest extent 
possible, whereas Bosch and Intel supported harmonization of NHTSA's 
BSW procedure with ISO 17387:2008, Intelligent transport systems--Lane 
change decision aid systems (LCDAS)--Performance requirements and test 
procedures. Bosch asserted that adopting the ISO standard would lessen 
testing complexity and burden on manufacturers, while still offering a 
system to evaluate system performance and robustness. For BSI 
assessments, Auto Innovators and Bosch urged the Agency to harmonize 
its test procedures with ISO 19638:2018. Both Auto Innovators and GM, 
in addition to Aptiv, noted that the lane widths specified (3.7 to 4.3 
m, or 12 to 14 ft.) do not align with U.S. lane width standards and 
suggested that the Agency consider aligning the lane width 
specifications to Euro NCAP's: 3.5 to 3.7 m (11.5 to 12 ft.).
    Other comments focused on specific procedural changes, with Aptiv 
raising concerns regarding the onset and termination headways specified 
in the BSW test procedure. The company recommended that the alert 
engagement requirement be defined as a minimum defined distance and be 
extinguished when the POV exits the forward boundary of the defined 
blind zone. Aptiv explained that this should reduce consumer confusion 
since the driver should be able to visually see the vehicle outside of 
the blind zone by this point, but the BSW could still be illuminated.
    NHTSA also received comments on test applicability. Specifically, 
several commenters suggested that the Agency should only test blind 
spot systems that cannot be disabled by the driver.
Response to Comments and Agency Decisions
    The original lane width specifications for BSW and BSI testing of 
3.7 to 4.3 m (12.0 to 14.0 ft.) were selected to overlap with American 
Association of State Highway and Transportation Officials (AASHTO) 
recommendations,\338\ to promote consistency with other NHTSA ADAS test 
procedures, and to allow flexibility to contract laboratories which 
could perform blind spot system testing. However, NHTSA's intent is to 
consider harmonization with other global testing programs wherever 
possible. Because of this strong interest, lane width specifications 
for BSW and BSI testing have been revised to be 3.5 to 3.7 m (11.5 to 
12 ft.), consistent with Euro NCAP's lane width requirements.
---------------------------------------------------------------------------

    \338\ See https://safety.fhwa.dot.gov/geometric/pubs/mitigationstrategies/chapter3/3_lanewidth.cfm.
---------------------------------------------------------------------------

    NHTSA agrees with Bosch that alignment with elements of ISO 
standards (in addition to elements of other testing programs such as 
those in Euro NCAP) should lessen complexity and burden on vehicle 
manufacturers. Regarding harmonization with ISO 17387:2008 for BSW 
testing, several revisions have been made to better align the Agency's 
testing protocol and this ISO standard. Changes to the definition of 
the two-dimensional polygon representing the SV and POV, the range of 
POV lateral velocities used during the Straight Lane Converge and 
Diverge test, and the maximum SV blind zone width specification were 
made in response to the November 2019 publication of the draft BSW 
procedures. As noted earlier in this section, specific changes made in 
response to that earlier publication are reflected in updated BSW test 
procedures published in the docket for this notice.
    NHTSA also concurs with commenters suggesting edits to the onset 
and termination headways in BSW testing. As such, the test procedure 
has been revised to clarify that the onset of the BSW is unrestricted 
and to state that the warning must be presented by a time no later than 
300 ms after any part of the POV enters the SV blind zone, defined 
earlier. The intent of the onset requirement was to ensure that the BSW 
is presented by a certain time, not to restrict it from appearing 
earlier. Additionally, NHTSA has amended the duration of the required 
alert; the alert must remain on while any part of the POV resides 
within the SV blind zone during converge lane changes. For the Converge 
and Diverge test scenario, the alert must not be active once the 
lateral distance between the SV and the POV is greater than 6 m (19.7 
ft.). For the Pass-by scenario, the alert must not be active once the 
longitudinal distance between the frontmost part of the SV and the 
rearmost part of the POV exceeds the BSW termination distances provided 
in the test procedure. These range in length from 2.2 m (7.3 ft.) for 
the 80.5 kph (50 mph) condition to 8.9 m (29.3 ft.) for the 104.6 kph 
(65 mph) condition.
    Finally, to provide as much information as possible to consumers 
regarding BSW and BSI systems in new vehicles, at this time, NHTSA will 
not consider whether the system may be disabled when it provides 
assessment results to the public. Thus, all BSW and BSI systems will be 
eligible for NCAP credit. However, to receive credit for BSW and BSI 
systems during program testing, NHTSA will require the BSW or BSI 
systems to appear `Default ON' during each ignition/key cycle. The 
Agency does not expect blind spot technology's already high consumer 
satisfaction to decrease because of this requirement. NHTSA also 
expects drivers will adjust their system's settings to meet their 
personal preferences instead of disengaging the system altogether.
11. Future Considerations
Use of Additional Test Devices
    As mentioned in the March 2022 RFC, in response to prior RFC 
notices, many commenters previously recommended that the Agency expand 
blind spot system testing requirements to include motorcycle and 
bicycle detection. In response to the Agency's latest RFC, Somerville 
Bicycle Safety also voiced support for NHTSA using bicycle test devices 
in its BSW testing, stating that Euro NCAP is already performing this 
testing. Others also agreed that bicyclists should be accounted for in 
BSW and BSI testing. MIC/MSF, Lidar Coalition, and AMA requested that a 
motorcyclist test device be added so that manufacturers design their 
vehicles to recognize motorcyclist signatures. Many commenters also 
noted that motorcyclists and bicyclists are inherently more vulnerable 
to serious and fatal injuries as compared with occupants of motor 
vehicles.
Incorporate Other Scenarios or Technology
    Many commenters suggested that NHTSA ensure all ADAS technologies 
assessed, including BSW and BSI, perform to a high standard in order to 
receive credit or the highest rating possible. This included good 
performance in darkness, in inclement weather, and while turning. The 
Agency has also received similar comments in response to prior RFC 
notices.
    Many commenters also recommended that NHTSA address other potential 
blind zones drivers may experience. In addition to the lateral blind 
zones assessed for motor vehicle presence in the Agency's BSW/BSI test 
procedures, commenters asserted that NHTSA should address blind zones 
to the front and rear of the vehicle, which may also exist, 
particularly in large vehicles, as they may create a potentially 
hazardous situation for VRUs. Many commenters

[[Page 96042]]

noted that assessments for these blind spots were not proposed and 
requested that the Agency take them into consideration when developing 
BSW and/or BSI procedures.
Response to Comments and Agency Decisions
Use of Additional Test Devices
    As mentioned in its 2022 RFC notice, NHTSA agrees that BSW and BSI 
systems capable of detecting motorcycles and bicyclists would improve 
safety. A review of the 2011-2015 FARS and GES data sets \339\ showed 
there were 106 fatal crashes and nearly 5,100 police-reported crashes 
annually, on average, for same-direction lane change crashes involving 
a vehicle and motorcycle. In comparison, there were 542 fatalities and 
503,070 police-reported crashes annually, on average, for lane change 
crashes involving motor vehicles. These data show that although more 
motor vehicle occupants than motorcyclists die in lane changing 
crashes, the fatality rate for motorcyclists is greater than that for 
vehicle occupants, as several commenters asserted. While the Agency is 
not aware of specific crash data for pedalcyclist lane change crashes 
involving light vehicles, NHTSA recognizes that cyclist fatalities are 
on the rise, as there were 938 pedalcyclist fatalities in 2020, 
representing a 9 percent increase over 2019. Pedalcyclist fatalities 
accounted for 2.4 percent of all traffic fatalities and 38,886 
pedalcyclist injuries that year.\340\
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    \339\ Swanson, E., Azeredo, P., Yanagisawa, M., & Najm, W. 
(2018, September), Pre-Crash Scenario Characteristics of Motorcycle 
Crashes for Crash Avoidance Research (Report No. DOT HS 812 902), 
Washington, DC: National Highway Traffic Safety Administration. In 
Press.
    \340\ NHTSA Traffic Safety Facts, June 2022, Bicyclists and 
Other Cyclists, DOT HS 813 322.
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    At this time, the Agency has decided to prioritize testing of BSW 
and BSI systems on motor vehicles (excluding motorcycles) for NCAP. 
NHTSA maintains that a focus on vehicle detection is a reasonable 
initial step forward and that performing blind spot system testing on 
light vehicles, particularly at higher POV closing speeds, should 
encourage development of robust sensing systems, which may improve the 
detection of VRUs such as motorcyclists and bicyclists. The Agency has 
conducted preliminary research designed to evaluate vehicle response to 
VRUs.
    As part of this research effort, conducted under contract with the 
Transportation Research Center Inc. (TRC Inc.), the Agency utilized its 
current BSI test procedures but varied the POV test device (e.g., GVT 
and motorcycle) and the SV/POV speed (as applicable, depending on test 
scenario).\341\ NHTSA found that, overall, the vehicles tested 
displayed performance differences between the surrogate passenger 
vehicle (i.e., GVT) and the surrogate motorcycle test device in the 
lane change scenarios assessed. For instance, one vehicle was able to 
detect the GVT in a blind spot for all test speeds for the SV Lane 
Change, Constant Headway tests but did not issue a detection alert when 
the motorcycle test device was within the blind spot. A similar 
observation was made for a vehicle in the SV Lane Change, Closing 
Headway BSI scenario. The vehicle failed to issue a blind spot warning 
at 40 kph (24.9 mph) when the motorcycle test device was within its 
blind spot, but it appropriately issued an alert for the GVT at this 
test speed. From this, it can be concluded that incorporating a 
motorcycle test device into the Agency's current blind spot test 
procedures would help to address these specific collision types.
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    \341\ The report, Assessment of Light Vehicle ADAS Crash 
Avoidance Technologies in Response to Two-Wheeled Vehicles as 
Principal Other Vehicles, can be found in the docket for this 
notice.
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    NHTSA also plans additional research focused on characterizing the 
capabilities and limitations of available BSI systems, both on-road and 
closed track. As part of this work, the Agency plans to review crash 
datasets and develop additional test scenarios for motorcycles and/or 
bicyclists to align with the safety need. Further, as noted in the NCAP 
Roadmap section in this final decision notice, NHTSA plans to implement 
in NCAP BSW and BSI evaluation to mitigate crashes with motorcyclist 
and bicyclist crashes starting with model year 2031 vehicles.
Incorporate Other Scenarios or Technology
    While NHTSA recognizes the need to assure crash avoidance systems 
perform well under all situations that a driver may encounter, it is 
not currently practical to evaluate each within the scope of NCAP. 
Therefore, the most frequent fatal and injurious conditions will be 
prioritized for evaluation. When BSW and BSI systems perform acceptably 
in these conditions (i.e., clear, daylight, straight and flat road) and 
are present in the fleet in sufficient numbers, NHTSA will evaluate 
real-world conditions at that time to determine whether additional 
condition(s) should be subsequently addressed.
    The Agency also acknowledges commenter concerns regarding driver 
visibility. Commenters noted that certain vehicles, including large 
vehicles such as pickup trucks and SUVs, may have additional blind 
zones to the front and rear of the vehicle. As mentioned in the NCAP 
Roadmap section of this notice, NHTSA is currently conducting research 
on driver visibility to mitigate VRU injuries and fatalities. The 
results of this research will inform the Agency on the most appropriate 
approach to reduce harm to these difficult-to-see VRUs.

VII. Updating Lane Keeping Technologies

    NHTSA has decided to (1) retain its assessment for lane departure 
warning (LDW) and to (2) add an assessment for lane keeping assist 
(LKA) for this NCAP update. As mentioned in the Agency's March 2022 
RFC, lane keeping technologies, including LDW, LKA, and LCA,\342\ can 
address ten pre-crash scenarios, including roadway departure scenarios 
and those in which the SV passively crosses the centerline or center 
median and strikes a vehicle travelling in the opposite direction. 
These scenarios resulted in 1.13 million crashes (19 percent of all 
U.S. crashes), 14,844 fatalities (44 percent of all fatalities), and 
479,939 MAIS 1-5 injuries (17 percent of all injuries recorded), 
annually on average between 2011 and 2015, showing there is a 
significant safety need.343 344
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    \342\ LDW alerts the driver when the car approaches or crosses 
lane markings, LKA gives steering support to assist the driver in 
preventing the vehicle from departing the lane, and LCA provides 
automatic steering to continually center the vehicle in its lane.
    \343\ Wang, J.-S. (2019, March), Target crash population for 
crash avoidance technologies in passenger vehicles (Report No. DOT 
HS 812 653), Washington, DC: National Highway Traffic Safety 
Administration.
    \344\ When only serious injuries (i.e., MAIS 3-5 injuries) were 
considered, lane keeping crashes represented the highest number of 
non-fatal injuries (21,282 or 0.76 percent of all non-fatal 
injuries), followed by rear-end crashes (17,918 or 0.64 percent), 
forward pedestrian crashes (5,973 or 0.21 percent), blind spot 
crashes (3,476 or 0.12 percent), and backing crashes (454 or 0.02 
percent).
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A. Lane Keeping Technologies

1. Lane Departure Warning (LDW)
    LDW is a NHTSA-recommended technology \345\ currently included in 
NCAP to mitigate the aforementioned lane departure crashes in which a 
driver unintentionally allows a vehicle to drift out of its lane of 
travel. LDW systems often use camera-based sensors to detect

[[Page 96043]]

lane markers, such as solid lines (including those marked for bike 
lanes), dashed lines, or raised pavement markers such as Botts' Dots 
\346\ used to delineate the vehicle's travel lane.\347\ When a LDW 
system detects that a vehicle is laterally approaching or crossing a 
lane marking, the system presents an alert to warn the driver of the 
unintentional shift so the driver can steer the vehicle back into its 
lane. LDW alerts may be visual, auditory, and/or haptic in nature. 
Visual alerts may show which side of the vehicle is departing the lane, 
and examples of haptic alerts include steering wheel or seat vibrations 
to alert the driver. If the driver's turn signal is activated, the LDW 
system interprets the lane change as an intentional act and thus does 
not alert the driver.
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    \345\ NHTSA-recommended technologies are driver assistance 
technologies for which the Agency has developed performance tests 
and metrics, and which meet the four prerequisites for inclusion.
    \346\ Botts' Dots are round, raised, non-reflective, pavement 
markers that mark travel lanes.
    \347\ Note that performance of LDW systems may be adversely 
affected by precipitation or poor roadway conditions due to 
construction, unmarked intersections, faded/worn/missing lane 
markings, markings covered with water, etc.
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    NHTSA proposed adoption of LDW systems (along with FCW systems) in 
its NCAP ADAS evaluations starting with 2011 model year vehicles 
because these systems were deemed to meet the Agency's four 
prerequisites for inclusion at the time.\348\ While the Agency 
estimated that then-current LDW systems were only 6 to 11 percent 
effective in preventing lane departure crashes, NHTSA cited the large 
number of road departure and opposite direction crashes occurring on 
the nation's roadways as well as the resulting AIS 3+ injuries as 
reasons to include LDW in NCAP.
---------------------------------------------------------------------------

    \348\ 73 FR 40033 (July 11, 2008).
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    Since LDW's adoption in NCAP, more recent studies have provided 
varying statistics with respect to LDW effectiveness. In a 2017 
study,\349\ IIHS concluded that LDW systems were effective at reducing 
three types of passenger car crashes (single-vehicle, sideswipes, and 
head-on) by 11 percent, which is the same rate NHTSA originally 
estimated. Further, IIHS also concluded that LDW systems reduce 
injuries in those same types of crashes by 21 percent. UMTRI, however, 
found in its study of real-world effectiveness of crash avoidance 
technologies in GM vehicles that LDW systems showed only a 3 percent 
reduction (determined to be not statistically significant) for 
applicable crashes.\350\ A second, more recent study \351\ conducted by 
the Partnership for Analytics Research in Traffic Safety (PARTS) also 
showed more limited effectiveness for LDW systems. In the PARTS study, 
police-reported crash data (2016 to 2021) from 13 states was combined 
with vehicle equipment data from 47 million vehicles from eight \352\ 
vehicle manufacturers, representing 93 vehicle models spanning from 
model years 2015 to 2020. The resulting study dataset of 2.4 million 
crash-involved vehicles did not find a significant reduction in single-
vehicle road departure crashes for vehicles equipped with LDW alone.
---------------------------------------------------------------------------

    \349\ Insurance Institute for Highway Safety (2017, August 23), 
Lane departure warning, blind spot detection help drivers avoid 
trouble, https://www.iihs.org/news/detail/stay-within-the-lines-lane-departure-warning-blind-spot-detection-help-drivers-avoid-trouble.
    \350\ Flannagan, C. and Leslie, A. (2020). Crash Avoidance 
Technology Evaluation Using Real-World Crash Data (No. DOT HS812 
841). United States. Department of Transportation. National Highway 
Traffic Safety Administration.
    \351\ Aukema, A., Berman, K., Gaydos, T., Sienknecht, T., Chen, 
C.-L., Wiacek, C., Czapp, T., & St. Lawrence, S. (2023) Real-World 
Effectiveness of Model Year 2015-2020 Advanced Driver Assistance 
Systems. 27th International Technical Conference on the Enhanced 
Safety of Vehicles, Paper Number 23-0170.
    \352\ The eight participating industry partners that provided 
vehicle data for this study are American Honda Motor Co., Inc., 
General Motors LLC, Mazda North American Operations, Mitsubishi 
Motors R&D of America, Inc., Nissan North America, Inc., Stellantis 
(FCA US LLC), Subaru Corporation, and Toyota Motor North America, 
Inc.
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    Other studies have suggested reasons for lower LDW effectiveness 
rates, one of which is higher driver deactivation rates caused by 
dissatisfaction with system functionality. In a survey of Honda 
vehicles brought into Honda dealerships for service,\353\ IIHS 
researchers found that out of 184 vehicles equipped with an LDW system, 
only a third of the vehicles had the system activated.
---------------------------------------------------------------------------

    \353\ Insurance Institute for Highway Safety (2016, January 28), 
Most Honda owners turn off lane departure warning, Status Report, 
Vol. 51, No. 1, page 6.
---------------------------------------------------------------------------

    In a similar study,\354\ 150 crash-involved Honda vehicles equipped 
with Event Data Recorders (EDRs) that captured data elements related to 
the function and alert status of several crash avoidance systems in the 
time leading up to the crash event were analyzed from NHTSA's 2017-2021 
Crash Investigation Sampling System (CISS). Starting with the 2016 
model year, Honda began to phase-in vehicles equipped with an EDR that 
captures the status and activation of crash avoidance technologies such 
as FCW/AEB and LDW/LKA. The EDR data were assessed to identify the use 
and activation statuses of these crash avoidance technologies at the 
time of the associated crash events. The results indicated that drivers 
of Honda vehicles equipped with crash avoidance systems were much more 
likely to have FCW/AEB systems ``On'' and LDW/LKA systems ``Off.'' 
Specifically, 99 percent of drivers for this study had FCW/AEB systems 
``On'' in the time leading up to the crash and thus could be afforded 
the benefits of these systems. With respect to LDW/LKA systems, 49 
percent of the drivers had these systems ``Off'' at the time of the 
crash, and therefore were not afforded the benefits of these systems. 
Differences were not identified for drivers that had the LDW/LKA system 
``On'' compared to those that had it ``Off'' with respect to the 
driver's sex, age, and race/ethnicity.
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    \354\ Wiacek, C., Firey, L., and Mynatt, M. (2023). EDR Reported 
Driver Usage of Crash Avoidance Systems for Honda Vehicles. Paper 
Number 23-0040. 27th International Technical Conference on the 
Enhanced Safety of Vehicles.
---------------------------------------------------------------------------

    Further, in its telematics-based study on LDW usage,\355\ UMTRI 
found that, overall, drivers turned off LDW systems 50 percent of the 
time. However, in Consumer Reports' August 2019 survey of more than 
57,000 CR subscribers, the organization found that 73 percent of 
vehicle owners reported they were satisfied with LDW technology.\356\
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    \355\ Flannagan, C., LeBlanc, D., Bogard, S., Nobukawa, K., 
Narayanaswamy, P., Leslie, A., Kiefer, R., Marchione, M., Beck, C., 
and Lobes, K. (2016, February), Large-scale field test of forward 
collision alert and lane departure warning systems (Report No. DOT 
HS 812 247), Washington, DC: National Highway Traffic Safety 
Administration.
    \356\ Consumer Reports (2019, November), Consumer Perceptions of 
ADAS, https://data.consumerreports.org/reports/consumer-perceptions-of-adas/.
---------------------------------------------------------------------------

    In its March 2022 RFC notice, the Agency proposed to continue to 
include LDW assessments in NCAP, as the system's adoption rate has not 
increased as significantly as that for FCW since the inclusion of both 
technologies in the program. When LDW was introduced in NCAP, its 
fitment rate was less than 0.2 percent.\357\ For the 2018 model year, 
the fitment rate for LDW was 30 percent. In contrast, the fitment rate 
for FCW saw an approximate 40 percent increase over the same period. 
Since LDW technology is currently not being offered as standard 
equipment on all passenger vehicles, the Agency reasons that it remains 
important for NCAP to continue to recommend the technology to new 
vehicle purchasers and inform shoppers which vehicles have systems that 
meet NHTSA's performance criteria. Furthermore, in recent years, many 
vehicle manufacturers have made improvements to sensors utilized by LDW 
systems for the purposes of implementing SAE Driving Automation

[[Page 96044]]

Level 2 systems such that LDW system effectiveness may improve, and 
consumer dissatisfaction may wane. Some of today's systems can assess 
if the driver is actively steering by measuring steering rate or torque 
on the steering wheel, or by utilizing direct or indirect driver 
monitoring systems. Furthermore, the sensing capability exists to 
suppress unnecessary LDW alerts and LKA activations in situations that 
require driving over a lane marker without the use of the turn signal, 
such as when trying to pass a bicyclist or drive around a pothole. 
Finally, since the Agency is also adopting LKA as part of this upgrade 
to NCAP, continuing to assess LDW functionality in addition to LKA, 
similar to assessing FCW in addition to AEB, and BSW in addition to 
BSI, should provide the greatest safety gains and most effectively 
address the number of fatalities and injuries related to lane departure 
crashes.
---------------------------------------------------------------------------

    \357\ Wang, J.-S. (2019, March), Target crash population for 
crash avoidance technologies in passenger vehicles (Report No. DOT 
HS 812 653), Washington, DC: National Highway Traffic Safety 
Administration.
---------------------------------------------------------------------------

NCAP's Current Lane Departure Warning Test Procedure
    In its March 2022 RFC notice, NHTSA proposed to continue its 
assessment of LDW systems under NCAP using the current NCAP test 
procedure titled, ``Lane Departure Warning System Confirmation Test and 
Lane Keeping Support Performance Documentation,'' dated February 
2013.\358\ This protocol assesses the system's ability to issue an 
alert in response to a driving situation intended to represent an 
unintended lane departure and to quantify the test vehicle's position 
relative to the lane line at the time of the LDW alert.
---------------------------------------------------------------------------

    \358\ National Highway Traffic Safety Administration. (2013, 
February). Lane departure warning system confirmation test and lane 
keeping support performance documentation. See http://www.regulations.gov, Docket No. NHTSA-2006-26555-0135.
---------------------------------------------------------------------------

    In NCAP's LDW tests, a test vehicle is accelerated from rest to a 
test speed of 72.4 kph (45 mph) while travelling in a straight line, 
parallel to a single lane line, comprised of one of three marking 
types: continuous white lines, discontinuous (i.e., dashed) yellow 
lines, or discontinuous raised pavement markers (i.e., a combination of 
Botts' Dots and other retro reflective pavement markers). The test 
vehicle is driven such that the centerline of the vehicle is 
approximately 1.8 m (6 ft.) from the lane edge. This path must be 
maintained, and the test speed must be achieved, at least 61.0 m (200 
ft.) prior to the start gate. Once the driver reaches the start gate, 
they manually input sufficient steering to achieve a lane departure 
with a target lateral velocity of 0.5 m/s (1.6 ft./s) with respect to 
the lane line. The driver of the vehicle does not activate the turn 
signal at any point during the test and does not apply any sudden 
inputs to the accelerator pedal, steering wheel, or brake pedal. The 
test vehicle is driven at a constant speed throughout the maneuver. The 
test ends when the vehicle crosses at least 0.5 m (1.7 ft.) over the 
edge of the lane line marking. The scenario is performed for two 
different departure directions, left and right, and for all three lane 
marking types, resulting in a total of six test conditions. Five 
repeated trials runs are performed per test condition.
    LDW performance for each test trial is evaluated by examining the 
proximity of the vehicle with respect to the edge of a lane line at the 
time of the LDW alert. The LDW alert must not be issued when the 
lateral position of the vehicle, represented by a two-dimensional 
polygon,\359\ is greater than 0.75 m (2.5 ft.) from the inboard edge of 
the lane line (i.e., the line edge closest to the vehicle when the lane 
departure maneuver is initiated), and must be issued before the lane 
departure exceeds 0.3 m (1 ft.). To pass the test, the LDW system must 
satisfy the pass criteria for three of the first five valid individual 
trials for each combination of departure direction and lane line type 
(60 percent) and for 20 of the 30 trials overall (66 percent).
---------------------------------------------------------------------------

    \359\ The two-dimensional polygon is defined by the vehicle's 
axles in the X-direction (fore-aft), the outer edge of the vehicle's 
tire in the Y-direction (lateral), and the ground in the Z-direction 
(vertical).
---------------------------------------------------------------------------

2. Lane Keeping Assist (LKA)
    Much like FCW and BSW, LDW's limitation is that it is merely a 
warning-based system. These systems do not actively mitigate crashes on 
the driver's behalf. Rather, they require driver input for any benefit 
to be realized. LKA, like AEB and BSI, is an active safety system. As 
such, its corrective actions are designed to be initiated without 
driver action.\360\
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    \360\ LKA differs from another active lane keeping technology, 
lane centering assist (LCA). LKA assists the driver by providing 
short-duration steering and/or braking inputs when a lane departure 
is imminent or underway; LCA provides continuous assistance to the 
driver to keep their vehicle centered within the lane.
---------------------------------------------------------------------------

    LKA systems can help prevent an unintended lane departure where the 
driver is not using the turn signal, and not actively steering (i.e., 
providing little to no steering wheel torque), to help prevent: 
``sideswiping,'' where a vehicle strikes another vehicle in an adjacent 
lane that is travelling in the same direction; opposite direction 
crashes, where a vehicle crosses the centerline and strikes another 
vehicle travelling in the opposite direction in an adjacent lane; and 
road departure crashes, where a vehicle runs off the road, resulting in 
a rollover crash or an impact with a tree or other object. In addition, 
LKA systems may also help to prevent unintended lane departures into 
designated bicycle lanes.
    LKA systems typically utilize the same sensor(s) used by LDW 
systems to monitor the vehicle's position within the lane and determine 
whether the vehicle is about to drift out of its lane of travel 
unintentionally. Because LKA systems help to guide a vehicle back into 
its lane without driver action, they further enhance safety beyond that 
achieved by LDW alone.
    In its study of real-world effectiveness of ADAS technologies, 
UMTRI found that LKA (when combined with lane departure warning 
functionality) showed an estimated 30 percent reduction in applicable 
crashes, whereas, as mentioned previously, LDW systems alone showed a 
reduction of only 3 percent, which was determined to be non-
significant.\361\
---------------------------------------------------------------------------

    \361\ Flannagan, C. and Leslie, A. (2020). Crash Avoidance 
Technology Evaluation Using Real-World Crash Data (No. DOT HS812 
841). United States. Department of Transportation. National Highway 
Traffic Safety Administration.
---------------------------------------------------------------------------

    While the PARTS study \362\ showed more limited effectiveness for 
LKA systems, it also highlighted the enhanced safety benefits offered 
by LKA compared to LDW systems. This study showed that single-vehicle 
road departure crashes were reduced by an estimated 8 percent (5 to 12 
percent) for vehicles equipped with both LDW and LKA systems, while, as 
mentioned earlier, the study did not find significant results for 
vehicles equipped with LDW alone. Similar effectiveness was observed 
for LKA systems in another recent study.\363\ For this study, 
production data for 11 model year 2015 through 2018 Toyota models were 
merged with police-reported crash files from eight U.S. states for 
crash years 2015 through 2019. The results showed LKA-equipped vehicles 
were 9 percent less likely to run off the road. However, vehicles 
equipped with LDW and LKA did not have a significant effect on risk of 
same-direction sideswipe or head-on crashes. As with LDW, the lower 
effectiveness rates for LKA systems stem

[[Page 96045]]

from overall driver dissatisfaction with combined LDW/LKA system 
functionality. This was evidenced by the referenced studies for Honda 
vehicles, discussed previously, which found high rates of deactivation 
with LDW/LKA systems.364 365
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    \362\ Aukema, A., Berman, K., Gaydos, T., Sienknecht, T., Chen, 
C.-L., Wiacek, C., Czapp, T., & St. Lawrence, S. (2023) Real-World 
Effectiveness of Model Year 2015-2020 Advanced Driver Assistance 
Systems. 27th International Technical Conference on the Enhanced 
Safety of Vehicles, Paper Number 23-0170.
    \363\ Spicer, R., Vahabaghaie, A., Murakhovsky, D., Bahouth, G. 
et al., (2021). ``Effectiveness of Advanced Driver Assistance 
Systems in Preventing System-Relevant Crashes,'' SAE Technical Paper 
2021-01-0869. doi:10.4271/2021-01-0869.
    \364\ Insurance Institute for Highway Safety (2016, January 28), 
Most Honda owners turn off lane departure warning, Status Report, 
Vol. 51, No. 1, page 6.
    \365\ Wiacek, C., Firey, L., and Mynatt, M. (2023). EDR Reported 
Driver Usage of Crash Avoidance Systems for Honda Vehicles. Paper 
Number 23-0040. 27th International Technical Conference on the 
Enhanced Safety of Vehicles.
---------------------------------------------------------------------------

    However, there is also evidence that consumers appreciate the 
inherent benefits LKA can provide. In an August 2019 survey, Consumer 
Reports found that 74 percent of vehicle owners reported they were 
satisfied with LKA technology.\366\ Further, 84 percent of model year 
2024 vehicles are equipped with LKA systems as standard equipment.
---------------------------------------------------------------------------

    \366\ Consumer Reports. (2019, November), Consumer Perceptions 
of ADAS, https://data.consumerreports.org/reports/consumer-perceptions-of-adas/.
---------------------------------------------------------------------------

    Based on these findings on system effectiveness and consumer 
acceptance, there is value in adopting LKA in NCAP to complement LDW 
systems and prevent or mitigate a greater number of lane departure 
crashes involving injuries and fatalities. By adopting objective test 
procedures to gauge LKA system performance for NCAP's assessments, the 
Agency will best ensure system robustness for future lane keeping 
systems having enhanced capabilities (e.g., lane centering).
Proposed LKA Test Procedure
    In its March 2022 RFC notice, the Agency proposed the adoption of 
certain test methods (e.g., those for LKA) contained within the Euro 
NCAP Test Protocol--Lane Support Systems (LSS) \367\ to assess 
technology design differences for LKA. Since the test speeds and road 
configurations specified in Euro NCAP's protocol are similar to those 
stipulated currently in the Agency's LDW test procedure, adopting Euro 
NCAP's test protocol would allow the Agency to sufficiently address the 
lane keeping crash typology currently covered for LDW while also 
harmonizing with the European organization.
---------------------------------------------------------------------------

    \367\ European New Car Assessment Programme (Euro NCAP) (2019, 
July), Test Protocol--Lane Support Systems, Version 3.0.2. See 
section 7.2.5, Lane Keep Assist (LKA) tests.
---------------------------------------------------------------------------

    Euro NCAP's current \368\ LSS test procedure includes a series of 
LKA trials performed with iteratively increasing lateral velocities 
towards the desired lane line. Each LKA trial begins with the subject 
vehicle (SV) being driven at 72 kph (44.7 mph) down a straight lane 
delineated by a single solid white or dashed white line. Initially, the 
SV path is parallel to the lane line, with an offset from the lane line 
that depends on what lateral velocity is desired later in the maneuver. 
Then, after a short period of steady-state driving, the SV transitions 
to a path defined by a 1,200 m (3,937.0 ft.) radius curve. The lateral 
velocity of the SV's approach toward the lane line (from both the left 
and right directions) is increased from 0.2 to 0.6 m/s (0.7 to 2.0 ft./
s) in 0.1 m/s (0.3 ft./s) increments or until acceptable LKA 
performance is no longer realized. Acceptable LKA performance occurs 
when the SV does not cross the inboard leading edge of the lane line by 
more than 0.3 m (1.0 ft.).
---------------------------------------------------------------------------

    \368\ European New Car Assessment Programme (Euro NCAP) 
(November 2022), Test Protocol--Lane Support Systems, Implementation 
2023. Version 4.2. Note that the Euro NCAP LSS test protocol has 
been updated from Version 3.0.2 since the March 2022 RFC's 
publication.
---------------------------------------------------------------------------

B. Linking Current and Proposed Lane Keeping Technology Test Scenarios 
to Real-World Crashes

    NCAP's current LDW test conditions, as well as the future LDW/LKA 
test conditions described in this notice, represent pre-crash scenarios 
that correspond to a substantial portion of fatalities and injuries 
observed in real-world lane departure crashes. A review of Volpe's 2011 
to 2015 data set showed that, when the posted speed limit was known, 
approximately 42 and 31 percent of fatalities in fatal road departure 
and opposite direction crashes, respectively, occurred when the posted 
speed was 72.4 kph (45 mph) or less.\369\ Similarly, the data indicated 
74 and 73 percent of injuries resulted from road departure and opposite 
direction crashes, respectively, that occurred when the posted speed 
was 72.4 kph (45 mph) or less.\370\ For crashes where the travel speed 
was reported in FARS and GES, approximately 17 and 26 percent of fatal 
road departure and opposite direction crashes, respectively, occurred 
at travel speeds of 72.4 kph (45 mph) or less. These data also showed 
that, where the travel speed was reported, 71 and 78 percent of the 
police-reported non-fatal road departure and opposite direction 
crashes, respectively, occurred at 72.4 kph (45 mph) or less.\371\ 
While this data suggests that speeding is prevalent in lane departure 
relevant pre-crash scenarios, particularly ones that result in 
fatalities, a test speed of 72.4 kph (45 mph) should address a 
measurable portion of the travel speeds where lane departure crashes 
are occurring.
---------------------------------------------------------------------------

    \369\ Swanson, E., Foderaro, F., Yanagisawa, M., Najm, W.G., & 
Azeredo, P. (2019, August), Statistics of light-vehicle pre-crash 
scenarios based on 2011-2015 national crash data (Report No. DOT HS 
812 745), Washington, DC: National Highway Traffic Safety 
Administration.
    \370\ Posted speed limit was unknown or not reported in 3 
percent of fatal road departure crashes and in 14 percent of road 
departure crashes with injuries. For opposite direction crashes, 
these figures were 1 percent and 13 percent, respectively.
    \371\ Travel speed was unknown or not reported in 63 percent of 
fatal road departure crashes and in 68 percent of road departure 
crashes with injuries. For opposite direction crashes, these figures 
were 65 percent and 67 percent, respectively.
---------------------------------------------------------------------------

    Volpe's data analysis also showed the predominant roadway 
configuration for real-world lane departure crashes (i.e., straight) 
also corresponds well with NCAP's test procedure. Of those road 
departure crashes in which roadway alignment was known, 63 percent and 
78 percent of fatal and injurious crashes, respectively, occurred on 
straight roads.\372\ For opposite direction-related crashes where 
roadway alignment was known, 70 percent of crashes with fatalities and 
68 percent of crashes with police-reported injuries occurred on 
straight roads.\373\ Additionally, for those road departure crashes 
where roadway grade was known, 71 percent of fatal crashes and 79 
percent of crashes with injuries occurred on level roads.\374\ For 
opposite direction crashes, these values were 68 percent and 69 
percent, respectively.\375\
---------------------------------------------------------------------------

    \372\ Roadway alignment was unknown or not reported in 1 percent 
and 4 percent of fatal and injurious road departure crashes, 
respectively.
    \373\ Roadway alignment was unknown or not reported in 1 percent 
and 2 percent of fatal and injurious opposite direction crashes, 
respectively.
    \374\ Roadway grade was unknown or not reported in 4 percent and 
19 percent of fatal and injurious road departure crashes, 
respectively.
    \375\ Roadway grade was unknown or not reported in 3 percent and 
16 percent of fatal and injurious opposite direction crashes, 
respectively.
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C. NHTSA's Proposals, Summary of Comments, Response to Comments, and 
Agency Decisions

1. Lane Keeping Technology Inclusion in General
    Most commenters supported the inclusion of active lane keeping 
technology in NCAP. Respondents in favor of keeping LDW and 
additionally incorporating LKA included advocacy groups, vehicle 
manufacturers, and individuals alike. Families for Safe Streets called 
LKA a ``critical safety feature,'' MEMA suggested that it is ``ripe'' 
for inclusion, and, like blind spot technologies, ITS America stated 
that NHTSA provided sufficient data to support adding it to NCAP's 
suite of testing. HMNA requested that LKA, along with the other four 
ADAS

[[Page 96046]]

features, should be added to NCAP ``as soon as possible.'' Having said 
this, a number of commenters cautioned the Agency to ensure that active 
lane keeping technologies do not interfere with a driver's attempt to 
pass a bicyclist or pedestrian at a safe distance.
2. Removal or Integration of LDW
    In its March 2022 RFC notice, the Agency noted that it agreed with 
commenters to the 2015 RFC notice who recommended that NHTSA adopt LKA 
technology in NCAP. However, instead of replacing LDW with LKA, as many 
commenters suggested, the Agency expressed that integrating its 
assessments for LDW into those for LKA may be a better approach to 
consider. Such a method (inclusive of passive and active safety 
capabilities for lane support systems) would be similar to that which 
the Agency has adopted for forward collision avoidance systems, FCW and 
AEB, as detailed earlier.
    As mentioned, the Agency proposed to adopt Euro NCAP's LKA test 
scenarios to assess technology design differences for LKA, and since 
the test speeds and road configurations specified in Euro NCAP's LSS 
protocol are similar to those stipulated in the Agency's current LDW 
test procedure, NHTSA stated that the Euro NCAP tests should 
sufficiently address the lane keeping crash typology for LDW as well. 
As such, NHTSA solicited comment on whether it should retain its 
separate LDW test protocol or integrate an LDW requirement into the LKA 
test procedure it ultimately adopts. The Agency suggested that for 
systems having both LDW and LKA capabilities, it would simply turn off 
LKA to conduct the LDW test if both systems are to be assessed 
separately.
Summary of Comments
    Many commenters, including ASC, Advocates, Aptiv, BMW, Bosch, GM, 
HATCI, IDIADA, Intel, Toyota, and TRC supported integrating the LDW 
assessment into the LKA test procedure.
Integrate Because of Testing Benefits
    Test laboratories IDIADA and TRC supported consolidating the LDW 
and LKA test procedures because doing so offered ``an advantage for 
those conducting the test'' (TRC) and was ``more convenient'' (IDIADA). 
GM also added that integrating the two test procedures would enhance 
efficiency.\376\
---------------------------------------------------------------------------

    \376\ See NHTSA-2021-0002-3856, Attachment A for more 
information.
---------------------------------------------------------------------------

Turn Off LKA Functionality To Assess LDW
    ASC, Honda, TRC, and Aptiv supported turning the LKA system off to 
evaluate LDW, with ASC and Aptiv also expressing support for evaluating 
LDW alone if LKA is not available. Having said this, Aptiv stated that 
integrating the LDW and LKA assessments may help drive offerings of 
LKA. TRC mentioned that many of the scenarios and line types are 
already similar and that separate assessments would be easy to perform 
by turning off the LKA feature to conduct LDW tests.
Integrate, But Assess as a System, Not Separately
    Auto Innovators recommended that since LDW and LKA interact 
together in the real world, and the combined system offers greater 
safety benefits than individual systems, assessments should be 
integrated to reduce test burden. The group suggested that LDW should 
not be assessed separately if LKA is provided, especially since not all 
systems allow disabling of LDW and/or LKA. The group generally 
supported harmonization with Euro NCAP's LSS protocol.
    GM also supported an assessment of overall system performance. Like 
Auto Innovators, the automaker did not agree with assessing LDW 
functionality separately for those vehicles equipped with active lane 
keeping features. The commenter mentioned that not only is the ability 
to turn off LKA independently from LDW not an option for most vehicles, 
but the Agency's proposal would both limit potential safety benefits 
[for LKS] and also continue to allow nuisance behavior from LDW 
systems. The manufacturer further asserted that adopting protocols that 
assess LDW functionality separately (within an LKA system) would limit 
optimization of feature behavior since modern lane keeping systems 
integrate LDW into LKA, such that the passive warning serves as a 
secondary alert to the active system (e.g., LKA, lane centering). In 
consideration of these comments, GM advocated that NHTSA only assess 
LDW functionality in cases where LKA fails to keep the vehicle in the 
lane per the test procedure requirements (regardless of whether the 
Agency maintains LDW as a separate assessment or integrates LDW 
assessments into an LKS test procedure).
    Similarly, Auto Innovators and Toyota commented that NHTSA should 
evaluate LKA performance first, and if the Agency's performance 
criteria is not met, only then should LDW performance be evaluated. 
Auto Innovators and BMW, in addition to GM, as mentioned above, agreed 
that passing LKA systems should automatically receive credit for LDW 
(no separate LDW assessment should be necessary). GM stated that this 
would be consistent with the current Work in Progress (WIP) of SAE 
J3240, whereas Auto Innovators and BMW cited EU emergency lane-keeping 
systems (ELKS) regulations, which consider steering and/or braking 
intervention to be a haptic LDW warning.\377\ Intel recommended that 
the Agency award additional points to LKA compared to LDW, since LKA 
can automatically prevent lane departures. HATCI also recommended that 
the Agency combine LDW and LKA requirements for vehicles having LKA 
functionality and retain a separate LDW assessment for those vehicles 
that do not. The manufacturer went on to say that it supports most of 
the test methods in Euro NCAP's LSS protocol because the safety need in 
the U.S. is similar.
---------------------------------------------------------------------------

    \377\ Commission Implementing Regulation (EU) 2021/646 of 19 
April 2021 laying down rules for the application of Regulation (EU) 
2019/2144 of the European Parliament and of the Council as regards 
uniform procedures and technical specifications for the type-
approval of motor vehicles with regard to their emergency lane-
keeping systems (ELKS) [2021] OJ L133/31, Sec.  3.5.3.1.2.
---------------------------------------------------------------------------

Integrate LDW and LKA, But Continue To Test LDW Separately in Certain 
Instances
    Some commenters agreed with combining LDW and LKA assessments but 
stated that LDW functionality should still be assessed separately for 
stand-alone LDW systems, or in instances where LKA can be disabled such 
that the system offers independent LDW functionality. In such cases, 
Bosch recommended performing Euro NCAP's single line LKA tests to 
assess performance for the LDW system. Advocates also supported 
aligning with Euro NCAP's LSS procedure and combining LDW and LKA 
testing if the Agency could justify doing so, but also mentioned that 
Euro NCAP's protocol specifies certain scenarios for LDW-only systems 
and systems that offer independent LDW functionality. The group also 
mentioned that the Agency should ``[rate] both LDW and LKS'' and weight 
the technology offering the greater safety benefits higher. Finally, 
IDIADA suggested LKA should have a performance-based assessment whereas 
LDW could be assessed based on fitment alone since LDW offers a much 
smaller safety benefit than LKA.

[[Page 96047]]

Do Not Integrate LDW and LKA
    Contrary to commenters who stated that the LDW and LKA assessments 
could be integrated, ZF Group and CAS recommended that LDW and LKA 
assessments be kept separate, particularly if either system can be 
disabled. DRI agreed. The test laboratory mentioned that it has seen 
varying performance for LDW depending on whether LKA was enabled or 
disabled, noting that when LKA was enabled, some vehicles would 
suppress the LDW alert as the LKA system attempted to intervene and 
keep the vehicle inside the lane, and then, when the intervention was 
not successful, the vehicle issued the LDW alert after the vehicle had 
departed from the lane. DRI further noted when LKA was disabled in 
those same vehicles, the LDW alerts were issued much earlier. As such, 
DRI concluded that, for vehicles where LDW and LKA are user selectable, 
vehicle manufacturers may vary the time of the LDW alert based on 
whether LKA is enabled. The test laboratory also noted that some LKA 
systems may intervene to the extent that one would have to impart 
additional steering toward the lane line (which may also suppress LDW 
if the vehicle senses the steering is intentional) to position the 
vehicle close enough to the lane line to issue an LDW alert.
    Rivian recommended the Agency perform separate assessments of LDW-
only, LKA-only, and LDW and LKA in combination. The manufacturer 
commented that this was most appropriate, particularly for user-
configurable systems, to allow consumers to understand the safety 
benefits of each system individually and in combination.
Other Related Comments
    Although Honda did not express a preference for removal of LDW or 
integration of the system into LKA, the automaker did support adoption 
of the LSS protocol used by Euro NCAP. Intel also expressly supported 
adopting the Euro NCAP protocol.
    FCA opined that the current LDW test procedure should be maintained 
for a transitional period of time before a new requirement is 
implemented. Similarly, ASC and Aptiv mentioned the need to continue to 
perform LDW-only assessments, at least initially, noting that not all 
vehicles are currently equipped with LKA because they do not have 
electric power steering.\378\
---------------------------------------------------------------------------

    \378\ ASC estimated that 85 percent of U.S. vehicles have 
electric power steering in 2022 and this number will increase to 92 
percent in 2027.
---------------------------------------------------------------------------

    Tesla stated that LDW points in Euro NCAP can be obtained either 
through the performance evaluation of an LDW system or presence of a 
BSI system; however, the automaker stated that NHTSA should evaluate 
the performance of LDW (rather than just presence) and BSI systems 
separately to ensure safety benefits for both systems are realized. 
Auto Innovators also noted that Euro NCAP's LSS test procedure contains 
the ELK--Overtaking scenario analogous to a scenario in NHTSA's BSI 
test procedure. However, the group suggested that the Agency keep LKA 
and BSI separate from one another since the U.S. market has accepted 
them as separate systems.
Response to Comments and Agency Decisions
    The Agency has chosen to integrate LDW and LKA testing, and as 
such, will evaluate LDW functionality during its LKA tests.
    Many commenters noted that LDW and LKA are two components of a 
larger lane departure mitigation system. Not only is it possible for 
the two systems to be enmeshed such that one may not be operational if 
the other is turned off, but the Agency's goal is for drivers to find 
lane keeping technologies supportive of the driving task and therefore 
leave them enabled. As Auto Innovators reiterated, the safety benefits 
of both systems together are greater than the benefits of a single 
system on its own. This improved safety cannot be realized if consumers 
choose to disable one or both of these systems. This holds true even if 
manufacturers choose to tune their LDW and/or LKA systems to compensate 
for the other system being turned off, for those vehicles which offer 
the option to do so. Although drivers may disable one or both systems 
according to their preference, the Agency finds it most advantageous to 
the consumer to integrate both components in its lane keeping 
technology assessment.
    Commenters suggested that NHTSA's NCAP should harmonize its lane 
keeping tests with Euro NCAP's LSS test procedure. At the time of 
publication of the March 2022 RFC, Euro NCAP evaluated LDW systems 
using its LKA single-line test, which used a lateral velocity of 0.2 m/
s to 0.5 m/s (0.7 ft./s to 1.6 ft./s), as previously noted.\379\ 
However, after the comment period for the March 2022 RFC closed, Euro 
NCAP introduced an updated protocol in which LKA single-line tests are 
conducted using lateral velocities of 0.2 m/s to 0.6 m/s (0.7 ft./s to 
2.0 ft./s), and the same procedure is used to evaluate LDW alerts from 
0.6 m/s to 1.0 m/s (2.0 ft./s to 3.3 ft./s) lateral velocity.\380\ It 
is unclear to the Agency whether these commenters desired harmonization 
based upon principle alone or whether commenters also believed that the 
specifications set at the time were appropriate.
---------------------------------------------------------------------------

    \379\ European New Car Assessment Programme (Euro NCAP) (July 
2019), Test Protocol--Lane Support Systems, Version 3.0.2.
    \380\ European New Car Assessment Programme (Euro NCAP) 
(December 2023), Test Protocol--Lane Support Systems, Version 4.3.
---------------------------------------------------------------------------

    At this time, performing LDW assessments using higher lateral 
velocities (i.e., 0.7 m/s to 1.0 m/s (2.3 ft./s to 3.3 ft./s)) would be 
more representative of intentional lane changes rather than 
unintentional drifting, which NHTSA's LDW tests are designed to 
address. For intentional lane changes, LDW warnings do not serve to 
address a crash problem and may be viewed as a nuisance by drivers who 
then look to disable the LDW system. Given this possibility, the Agency 
will assess LDW alert functionality from 0.2 m/s to 0.6 m/s (0.7 ft./s 
to 2.0 ft./s) in NCAP. These same lateral velocities 0.2 m/s to 0.6 m/s 
(0.7 ft./s to 2.0 ft./s) will also be used for NCAP's LKA assessments. 
Note that NHTSA's current LDW protocol specifies an allowable lateral 
velocity range of 0.1 m/s to 0.6 m/s; thus, the chosen lateral velocity 
range has already been in use to assess LDW performance.
    Since NHTSA's chosen LKA and LDW test specifications (i.e., test 
scenarios, SV speeds, lateral velocities, etc.) are identical and LDW 
and LKA are meant to work together as a system, the Agency has chosen 
to evaluate LDW functionality during LKA testing. Assessing both 
technologies during the same test will promote efficiency, as IDIADA, 
TRC, and GM suggested, and reduce test burden on both NHTSA and 
manufacturers. It should additionally prompt expanded fleet coverage 
for LKA technology, as Aptiv asserted, and allow dual system 
optimization, as GM contended. In that vein, NHTSA expects that 
integrating LDW and LKA protocols will lead to a reduction in nuisance 
alerts.
    HATCI's comment regarding the applicability of Euro NCAP's protocol 
to the U.S market due to similar safety need is sound overall. That 
said, NHTSA also agrees with Tesla and Auto Innovators that BSW/BSI and 
LDW/LKA should be evaluated separately since the Agency's desire is to 
address intended and unintended lane changes separately. Euro NCAP 
evaluates BSW (called ``Blind Spot Monitoring'', or

[[Page 96048]]

BSM) and BSI using its Emergency Lane Keeping (ELK) Overtaking Vehicle 
scenario within its LSS protocol. For the Overtaking Vehicle test, lane 
keeping performance is evaluated using lateral velocities from 0.5 m/s 
to 0.7 m/s (1.6 ft./s to 2.0 ft./s), a path containing a smaller radius 
of curvature (800 m, or 2,625.0 ft.), and engagement of the turn 
signal. These requirements are designed to simulate conditions for an 
intentional lane change.
    Because the Agency will assess LKA and LDW as a system, if a 
vehicle fails to adequately intervene using LKA during a lane 
departure, the Agency will not conduct further evaluation with the 
intent to provide the vehicle LDW credit only, as some commenters 
requested. NHTSA also will not separately evaluate LDW systems on 
vehicles that do not offer LKA as part of this NCAP update. These 
vehicles will not receive lane keeping technology credit for meeting 
NHTSA-approved performance metrics and the Agency will not report the 
presence of LDW on its website. These decisions are similar to those 
which the Agency has made for FCW and AEB. The Agency reasons this NCAP 
update is an opportunity to increase performance requirements for new 
vehicles to gain lane keeping technology credit to inform consumer 
decisions, and it is now most appropriate to highlight the performance 
of LKA systems, not LDW, given the greater safety gains that active 
technology may offer. Maintaining the current LDW protocol, even for a 
transitional period of time, as FCA requested, would not accomplish 
this goal. Having said this, the Agency does not want to discount the 
importance of the LDW alert to passing lane keeping scores. LKA can 
provide the necessary steering correction to prevent a roadway 
departure; however, for a distracted or inattentive driver, the LDW 
alert may still be necessary to ensure driver re-engagement. As will be 
detailed in a later section, a vehicle that fails to issue an LDW alert 
that conforms to NHTSA's requirements will not receive credit for lane 
keeping technology, regardless of whether the vehicle's LKA system 
provided acceptable intervention. Furthermore, as will be discussed 
later, while an LKA intervention will suffice as an LDW alert 
component, it will not be sufficient to satisfy all LDW alert 
requirements. As such, vehicles will not automatically receive LDW 
credit for a passing LKA intervention, as several commenters requested.
3. Lane Marking Configurations
    Euro NCAP's LSS protocol specifies a single lane line to evaluate 
LKA system performance.\381\ Citing the possibility that certain LKA 
systems may require the presence of lane lines on either side of the 
vehicle's travel lane before they can be enabled, the Agency sought 
comment on whether it should require the use of a single lane line or 
two lane lines on the test surface in its final LKA test procedure.
---------------------------------------------------------------------------

    \381\ European New Car Assessment Programme (Euro NCAP) 
(December 2023), Test Protocol--Lane Support Systems, Version 4.3.
---------------------------------------------------------------------------

Summary of Comments
    Many commenters favored adopting a test procedure featuring one 
lane line, while several others supported adoption of two lane lines.
Adopt a Single Lane Line
    Those in favor of a single lane line included Aptiv, Intel, AASHTO, 
ASC, ZF Group, HATCI, Honda, Auto Innovators, Bosch, and Tesla. AASHTO 
stated that testing with a single lane line would best mimic real-world 
conditions, as oftentimes only one line is visible, even on two lane 
roads, due to wear and tear, snow, etc. Bosch provided similar 
comments, stating that center road lines are often not detectable, 
particularly on rural roads, and recommended using one lane line to 
assess LKA performance to ``maximize LKS system availability'' under 
such conditions. In its comments, ASC additionally mentioned that 
testing with a single lane line will encourage systems to operate in 
situations where only one line is present. Similarly, Honda opined that 
testing with a single lane line would incentivize systems to perform 
better on a greater number of roadway conditions and prevent lane 
departures when only one lane line is detected. HATCI, ASC, and Auto 
Innovators recommended adopting a single lane for U.S. NCAP testing to 
harmonize with Euro NCAP's LSS protocol. Similarly, ZF Group 
recommended adopting a single lane line to ``promote uniformity.''
Adopt Two Lane Lines
    AAA and GM recommended that NHTSA adopt two lane lines rather than 
one in its LKA test procedure to best replicate real-world roadways. 
BMW, FCA, and TRC similarly recommended utilizing two lane lines to 
evaluate system performance because two-line lanes are more common on 
public roads in the U.S. In fact, FCA remarked (contrary to Auto 
Innovators) that roads having single lane lines are ``rare'' in this 
country compared to others. TRC also added that selecting a two-line 
lane marking configuration would permit more testing locations.
Incorporate Both One Lane Line and Two Lane Lines
    Two commenters, CAS and Rivian, stated that the Agency should 
incorporate assessments for both one and two lane lines into NHTSA's 
LKA test procedure, since both line formats are present on U.S. roads. 
Rivian suggested that NHTSA should reward systems that perform well for 
both lane line types with higher scores.
Other Comments
    Honda acknowledged that two lane lines may be required to 
initialize an LKA system but assumed the Agency was referring to the 
``operation design domain for LKS systems'' in its reference to 
``before they can be enabled,'' and not an initialization process. The 
automaker asked that the Agency clarify the meaning of the referenced 
statement. Auto Innovators also referenced the need to drive a vehicle 
between two lane lines in some instances to assure system 
initialization prior to testing with one lane line. The commenter, 
along with Tesla, generally supported harmonization with Euro NCAP LSS 
protocols. However, Tesla also mentioned that if NHTSA were to adopt 
two lane lines to address evaluations of LKA systems that require two 
lines to be enabled, the Agency should evaluate how a system reacts to 
crossing only the near side lane line as well as both lane lines and 
modify passing criteria and points appropriately. Tesla further 
asserted that the far side lane line should trigger the LKA system, 
which in turn should reduce false-positive and true-negative LKA system 
interventions in the real world.
    The Advocates stated that NHTSA should conduct an analysis of road 
edge lines across states and correlate this information with crash data 
before deciding to incorporate one lane line type or another into its 
LKA test procedure. Citing NHTSA data that showed 7,424 fatalities 
occurred on rural local/collector roads in 2021 (i.e., 17 percent of 
all fatalities),\382\ the group surmised that a large number of crashes 
may be occurring on roads having only a dashed or solid center line. 
The Advocates suggested that NHTSA provide data to show whether testing 
with one or two lane lines is more demanding on LKA systems and

[[Page 96049]]

whether one lane marking format better exposes system deficiencies.
---------------------------------------------------------------------------

    \382\ https://crashstats.nhtsa.dot.gov/Api/Public/ViewPublication/813298.
---------------------------------------------------------------------------

    Finally, regarding lane marking specifications themselves, Toyota 
and Auto Innovators commented that lane marking length should be 
specified since it serves as a ``recognition process for the system.'' 
The entities recommended a minimum lane marking length of 300 m (984 
ft.). Aptiv and ASC recommended that the Agency align lane widths used 
during LDW and LKA testing (currently 3.6 to 4.3 m (12 to 14 ft.)) with 
U.S. lane width standards, which specify a lane width of 2.7 to 3.6 m 
(9 to 12 ft.). Accordingly, the companies requested that NHTSA specify 
a maximum lane width of 3.7 m (12 ft.), which they stated would also 
better harmonize with Euro NCAP, which specifies a lane width of 3.5 to 
3.7 m (11.5 to 12 ft.). ASC also added that NHTSA should always 
reference the latest Manual on Uniform Traffic Control Devices (MUTCD) 
published by the Federal Highway Administration (FHWA) for lane marking 
and road configurations.\383\
---------------------------------------------------------------------------

    \383\ 23 CFR 655, Subpart F.
---------------------------------------------------------------------------

Response to Comments and Agency Decisions
    For the purposes of evaluating a vehicle's LDW alert sensitivity 
and primary LKA intervention capabilities, NHTSA's testing will include 
the use of (1) a single solid white lane line, (2) a single dashed 
yellow lane line, or (3) Botts' Dots on either the right or left side 
of the vehicle's travel lane, depending on testing direction. These 
lane line colors and types are currently specified in NCAP's LDW test 
procedure. These lane line colors/types remain acceptable for NHTSA's 
testing because, per the FHWA's MUTCD, yellow lane markings for 
longitudinal lines are permitted to delineate, among other things: (1) 
the separation of traffic traveling in opposite directions and (2) the 
left-hand edge of the roadways of divided highways and one-way streets 
or ramps. White markings for longitudinal lines are permitted to 
delineate: (1) the separation of traffic flow in the same direction or 
(2) the right-hand edge of the roadway.\384\ The MUTCD also states that 
a solid line shall be used to discourage or prohibit crossing 
(depending on the specific application) and a broken line shall be used 
to indicate a permissive condition.\385\ Further, raised pavement 
markers, such as Botts' Dots, may serve as a substitute for pavement 
markings, as long as they simulate that pattern of the markings for 
which they substitute.\386\ Euro NCAP's LSS test protocol specifies the 
use of either a solid or dashed line present in the direction of 
departure for LKA and LDW tests.
---------------------------------------------------------------------------

    \384\ Manual on Uniform Traffic Control Devices for Streets and 
Highways, 11th Edition. U.S. Department of Transportation, Federal 
Highway Administration. December 2023. See Section 3A.05.
    \385\ Manual on Uniform Traffic Control Devices for Streets and 
Highways, 11th Edition. U.S. Department of Transportation, Federal 
Highway Administration. December 2023. See Section 3A.06.
    \386\ Manual on Uniform Traffic Control Devices for Streets and 
Highways, 11th Edition. U.S. Department of Transportation, Federal 
Highway Administration. December 2023. See Section 3B.14.
---------------------------------------------------------------------------

    Adopting the single-line approach for these evaluations should 
ensure that LDW and LKA systems can operate in a greater number of 
real-world situations. Though roadways are typically designed to 
contain two lane markings denoting left and right sides of the lane, 
road conditions may vary greatly. The Agency sees merit in several 
commenters' suggestions that sometimes only a single line may be 
visible due to road wear or precipitation. By isolating the test 
conditions to a single lane line on either the right- or left-hand side 
of the SV, the test will assess whether the vehicle can detect the lane 
line independent of its other surroundings, which may vary in an 
infinite number of ways. Since a real-world vehicle may not have a 
second lane line to confirm that a lane departure is occurring, a 
single-line test should improve sensing such that vehicles no longer 
require the second lane line for LDW or LKA to reliably function. 
Furthermore, the use of a single lane line for the Agency's tests 
should not restrict manufacturers from using a second lane line, when 
available, to inform a vehicle's LKA system and further improve 
performance in the myriad of scenarios a driver will encounter in the 
real world.
    Given the reasons above, systems which only require the presence of 
one lane line to function are preferable to those which require two 
(i.e., one on each side of the vehicle); however, certain complications 
arise when evaluating LKA system performance using only one lane line. 
NHTSA acknowledges concern exists regarding secondary lane departures 
that may occur after an LKA intervention. In these cases, the vehicle 
steers back into the lane but then overcorrects and departs the lane on 
the opposite side of the original intervention. These cases cannot be 
accounted for during tests in which there is only one lane line. 
Therefore, the Agency will also perform additional testing with two 
lane lines to evaluate a vehicle's ability to properly correct the 
vehicle's heading after the initial intervention. As detailed in a 
subsequent section, the lane markings for this test series will consist 
of (1) a right solid white line and a left dashed white line, meant to 
simulate an SV traveling on a multi-lane road in the rightmost lane, 
and (2) a right dashed white line and a left solid yellow line, meant 
to simulate an SV travelling on a multi-lane road in the leftmost lane. 
These lane marking configurations are similar to those used \387\ in 
Euro NCAP's Emergency Lane Keeping (ELK) Solid Line test 
scenarios.\388\ However, unlike in Euro NCAP's testing, for each dual 
line configuration, assessments will be made for both left and right 
departures (i.e., across both dashed and solid lane lines).
---------------------------------------------------------------------------

    \387\ Euro NCAP's ELK Solid Line tests utilize only dashed white 
and solid white lane lines.
    \388\ European New Car Assessment Programme (Euro NCAP) 
(December 2023), Test Protocol--Lane Support Systems, Version 4.3. 
See Section 7.2.4.2.
---------------------------------------------------------------------------

    Thus, LKA testing will occur with both styles of lane markings: 
single lane lines on either the right or left side of the travel lane 
and two lane lines with one on each side of the vehicle. Vehicles 
traveling in real-world situations will likely encounter both 
scenarios, as CAS and Rivian remarked. By performing both single line 
and dual line assessments, NHTSA expects to ensure robust everyday 
performance. Systems will not be able to rely on the use of the second 
lane line for normal operation, but performance that is confounded by a 
second lane line should be evident.
    To address concerns regarding initialization of LDW and LKA 
systems, NHTSA plans to accept information from vehicle manufacturers 
detailing the procedures necessary to properly initialize systems for 
use. This information is already being collected prior to NCAP's 
current ADAS testing of new vehicle models. Further, the Agency is 
aware of cases where the vehicle must be driven a minimum number of 
miles in normal use conditions prior to assessment of ADAS 
technologies.
    Regarding other characteristics of lane markings, as with the BSW 
and BSI testing included in this final notice, NHTSA has decided to 
adopt a 3.5 m to 3.7 m (11.5 ft. to 12 ft.) lane width specification 
for its LDW and LKA tests for this NCAP update. In doing so, the Agency 
will align with Euro NCAP's LSS procedure and will more closely reflect 
AASHTO standards. The Agency will also impose a requirement that lane 
line markings extend for a minimum of 300 m (984 ft.), as Toyota and 
Auto Innovators requested. This lane line

[[Page 96050]]

length should be sufficient for LDW and LKA systems to interpret lane 
departures appropriately during the test validity period and 
accommodate secondary departure assessments. Finally, the Agency notes 
that it included the MUTCD as a reference for lane markings in both the 
LDW and draft LKA test procedures and has included it in the test 
procedures prepared for this NCAP update.
4. Botts' Dots/Raised Pavement Markers Test Condition
    In its March 2022 RFC notice, the Agency proposed to remove the 
Botts' Dots (i.e., raised pavement marker) test scenario from the 
current LDW test. This decision stemmed from the fact that information 
available to NHTSA suggested that the lane markers were being removed 
from use in California \389\ and a preliminary assumption that the 
traditional dashed and solid lane marking tests may be sufficient to 
evaluate vehicle performance.
---------------------------------------------------------------------------

    \389\ Winslow, J. (2017, May 19), Botts' Dots, after a half-
century, will disappear from freeways, highways, The Orange County 
Register, https://www.ocregister.com/2017/05/19/botts-dots-after-a-half-century-will-disappear-from-freeways-highways/.
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Summary of Comments
In Favor of Removal
    Those in favor of removing the Botts' Dots test scenario from the 
Agency's LDW test procedure included BMW, GM, HATCI, Honda, Auto 
Innovators, Bosch, TRC, MEMA, ASC, FCA, IDIADA, Intel, Tesla, and two 
individuals. Both HATCI and TRC cited reduced test burden as reasons to 
remove the Botts' Dots test condition. ASC, FCA, Intel, Tesla, and a 
public commenter all cited discontinued use in California as a reason 
for removal. Similarly, IDIADA mentioned that the Botts' Dots condition 
is becoming a ``niche scenario with low relevancy'' and Honda stated 
that there is no longer a safety need. TRC suggested replacing the 
Botts' Dots test condition with a road edge detection test because it 
is a more common real-world condition and possible at most testing 
laboratories.
Oppose Removal
    Although the overwhelming majority of commenters were in favor of 
removing the Botts' Dots test condition from the Agency's LKA test 
procedure, Rivian asserted that this test scenario was still a 
necessary assessment for LDW systems. The manufacturer contended that 
most vehicles would likely encounter Botts' Dots at some point since 
lane markings across the U.S. are not uniform. Rivian also stated that 
manufacturers may not design for this test condition if it was not part 
of NHTSA's test protocol which, in turn, would lead to reduced system 
effectiveness and overall safety. Along these lines, Advocates 
recommended that NHTSA provide information on the prevalence of Botts' 
Dots in states other than California and the length of time before 
Botts' Dots would be replaced before the Agency can be assured that 
removing them would not be a detriment to safety.
Response to Comments and Agency Decisions
    NHTSA has decided not to remove the raised pavement markers test 
scenario, which utilizes Botts' Dots, from its LDW/LKA test procedure 
for this NCAP upgrade. The Agency agrees with Rivian that it is 
possible vehicles may encounter Botts' Dots or other raised pavement 
markers in lieu of painted lane lines at some point during their useful 
life. In fact, more recent information from Caltrans, which manages 
over 50,000 miles of California's highway and freeway lanes, suggests 
the organization has no intention at this time of removing Botts' Dots 
from California's roadways.\390\ The Agency also recognizes that Botts' 
Dots or similar raised pavement markers are utilized in other states as 
well. The MUTCD provides guidelines for raised pavement markers as a 
substitute for broken line, solid line, and dotted lane line 
markings.\391\ Given this, and the fact that such pavement markers are 
unique compared to painted lane markings, NHTSA agrees with Rivian that 
retaining Botts' Dots assessments for NCAP's LDW/LKA assessments will 
best assure overall LDW/LKA system effectiveness and safety. The Agency 
reasons the slight increase in test burden such testing will generate 
is worth the assurance that vehicles will react appropriately if they 
encounter similar lane markings.
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    \390\ https://dot.ca.gov/programs/public-affairs/faqs.
    \391\ Manual on Uniform Traffic Control Devices for Streets and 
Highways, 11th Edition. U.S. Department of Transportation, Federal 
Highway Administration. December 2023. See Section 3B.17.
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    Having said this, NHTSA also acknowledges FHWA's most recent 
guidance to agencies in its December 2023 MUTCD that discourages the 
use of raised pavement markers as a substitute for lane markings when 
designing roadways for automated vehicles.\392\ As such, the Agency 
will monitor changes made to roadway lane demarcations to better 
accommodate forthcoming vehicle designs and may revisit the necessity 
of conducting test scenarios using Botts' Dots or other raised pavement 
markers in the future.
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    \392\ Manual on Uniform Traffic Control Devices for Streets and 
Highways, 11th Edition. U.S. Department of Transportation, Federal 
Highway Administration. December 2023. See Section 5B.02.
---------------------------------------------------------------------------

5. Addressing Secondary Departures
    The Agency explained in its March 2022 RFC notice that it would 
like to be assured that, when a vehicle is redirected after an initial 
LKA system intervention, if the vehicle then approaches the lane marker 
on the side not tested, the LKA will again engage to prevent a 
secondary lane departure by not exceeding the same maximum excursion 
limit established for the first side.
    To prevent secondary lane departures, NHTSA sought comments on 
whether it should consider modifying Euro NCAP's LKA evaluation 
criteria to be consistent with language developed for NHTSA's BSI test 
procedure to prevent this issue. NHTSA's BSI test procedure states that 
the SV's BSI intervention shall not cause the vehicle to travel more 
than 0.3 m (1 ft.) beyond the inboard edge of the lane line separating 
the SV's travel lane from the lane adjacent and to the right of it 
within the validity period. To assess whether this occurs, a second 
lane line is required; however, only one lane line is specified in the 
Euro NCAP LSS protocol for LKA testing. The Agency questioned whether 
the introduction of a second lane line would have the potential to 
confound LKA testing.
Summary of Comments
Agree With Adding Assessment for Secondary Lane Departures
    The majority of commenters (Advocates, ASC, BMW, CAS, Honda, Intel, 
Rivian, Tesla, TRC, and ZF Group) expressed support for NHTSA modifying 
the LKA test procedure to ensure tested LKA systems intervene a second 
time to prevent secondary lane departures.
    BMW did not comment that there was risk to adding a secondary lane 
line, since LKA systems are designed to align with the lane marking(s) 
after an intervention, but the commenter also recommended that the 
Agency adopt a two-line marked lane since it is most common. Along 
these lines, Intel recommended that, in adding a second lane line, 
NHTSA should ensure that the created lane represents real-world 
roadways and lane markings. Like BMW, ASC, Rivian, Tesla, and ZF Group 
reasoned that the addition of a second lane line should not adversely 
affect LKA performance. That said, ASC

[[Page 96051]]

asserted that it was reasonable to expect that LKA systems would 
prevent secondary departures regardless, and ZF Group similarly 
mentioned that the second lane line should simply trigger an LKA 
intervention. Rivian was supportive of adopting a test scenario that 
allowed the SV to `ping-pong' between lane lines two or more times to 
assess system functionality. CAS asserted that whether there is a lane 
line or not, the LKA system should keep the vehicle in the lane after 
an initial LKA intervention, and ensuring this functionality is 
important to consumers.
    While CAS maintained that, for safety reasons, no amount of 
excursion over the other lane line was acceptable for a secondary lane 
departure, Honda and ASC agreed that the Agency should adopt the same 
maximum excursion limits for primary and secondary lane departures. 
Honda saw no point in deviating since the current maximum limit is 
based on real-world data. The automaker also requested that the Agency 
adopt the appropriate roadway widths (based on real-world roadways) for 
the tested speeds if NHTSA adopts a second lane line. The commenter 
asserted that adopting a lane width that is too narrow for the speeds 
tested may cause inadvertent LKA system activation for the opposite 
lane line. Similarly, Intel remarked that a dually marked lane must be 
greater than a certain width so that the LKA system will have 
sufficient margin to not exceed the maximum excursion limit.
    Advocates also supported evaluating secondary lane departures but 
requested that if adding the second lane line reduces the stringency of 
lane or road departure tests, NHTSA should conduct the tests to assess 
prevention of secondary lane departures separately. Rivian suggested 
that the Agency reduce ratings for systems that struggle to prevent 
secondary lane departures. TRC preferred that LKA and BSI protocols 
have consistent language but also commented that secondary lane 
departure evaluations require increased space for testing.
Do Not Agree With Adding Assessment for Secondary Lane Departures
    Some commenters did not agree with modifying the LKA test procedure 
to ensure systems intervene to prevent secondary lane/road departures. 
Several of these commenters relayed that such an assessment was not 
necessary (Bosch and Toyota) or not warranted (Auto Innovators and GM). 
Bosch indicated that if the system avoids a departure on one side of 
the lane, and separately when tested for the other side of the lane, 
then it should prevent a secondary departure. FCA maintained that each 
lane departure intervention is a single event that ends after the 
intervention is complete. As such, the automaker considered a secondary 
lane departure to be a new lane departure event.
    Toyota and Auto Innovators stated that since LKA is designed to 
prevent or mitigate lane or roadway departures due to driver 
inattentiveness, drowsiness, etc., secondary departures should not 
serve as a basis to assess system performance. Likewise, GM commented 
that the first intervention serves to grab the driver's attention so 
that the driver intervenes to prevent a secondary departure. Auto 
Innovators and GM added that a driver-monitoring system may be 
necessary for those drivers who are not attentive after an initial LKA 
intervention, especially for those who may be misusing the system 
(e.g., driving with no hands on the wheel) and who purposely allow 
their vehicle to `ping-pong' between lane lines. Both groups further 
asserted that current systems are designed to re-center the vehicle in 
the lane after an intervention, not to direct the vehicle toward the 
opposite lane marker such that a secondary lane departure would occur.
    Along the lines of those comments from Auto Innovators and GM, IIHS 
expressed that it shares NHTSA's concern about ramifications of LKA 
interventions because the group's research \393\ has shown that many of 
those drivers involved in lane departure crashes were sleeping or 
otherwise incapacitated (34 percent); had a non-incapacitating medical-
issue, blood alcohol concentration (BAC) of 0.08 percent or more, or 
physical factor that could impair their ability to safely control a 
vehicle (13 percent), such that they would be unlikely to regain 
control of the vehicle after an initial LKA intervention. Accordingly, 
the group encouraged NHTSA to add to NCAP technologies that could 
detect such a driver and intervene to safely stop their vehicle, or 
preferably pull their vehicle over on the side of the road.
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    \393\ Cicchino & Zuby, 2017. Prevalence of driver physical 
factors leading to unintentional lane departure crashes. Traffic 
Injury Prevention, 18(5), 481-487.
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Response to Comments and Agency Decisions
    Given the comments received, the Agency has decided to incorporate 
additional LKA test scenarios that are comparable (though not 
identical) to Euro NCAP's Emergency Lane Keeping (ELK) Solid Line test 
to address secondary lane departures. NHTSA agrees with ASC that it is 
a reasonable expectation that LKA systems should prevent secondary 
departures, and, as CAS suggested, ensuring that LKA systems keep a 
vehicle in the lane after an initial intervention is important to 
consumers. It is also imperative for safety.
    Unlike the Agency's other LKA test scenarios, these secondary 
departure scenarios will utilize two lane lines to permit assessment of 
a secondary departure. Assessments will be made for two 
configurations--one simulating a vehicle travelling in the rightmost 
lane of a multi-lane road, with a solid white line to its right and 
dashed white line to its left, and the second simulating a vehicle 
travelling in the leftmost lane of a multi-lane road, with a solid 
yellow line to its left and a dashed white line to its right. Since 
these lane line combinations are common during real-world driving on 
multi-lane roads, they are appropriate for inclusion in NHTSA's 
testing. Also, utilizing a dashed white line and solid yellow line for 
the secondary departure tests effectively complements the Agency's 
dashed yellow and solid white single lane line tests, respectively.
    The Agency had expressed some concern in its March 2022 RFC notice 
that the addition of a second lane line in NCAP's lane keeping tests 
may confound LKA performance and thus test results. At the time, 
however, the Agency did not take into consideration that Euro NCAP's 
ELK Road Edge tests, which were/are performed similarly to their LKA 
tests, (and which the Agency is adopting for its LKA assessments), 
required a second lane line. Furthermore, Euro NCAP's LSS protocol has 
since been updated to include a second lane line for the program's ELK 
Solid Line tests, which will closely mirror the secondary departure 
tests adopted by NHTSA. As such, NHTSA now agrees with commenters that 
its initial concern was unwarranted. The Agency has not only adopted 
test parameters for the secondary departure test that align with Euro 
NCAP's current ELK Solid Line test (with the exception of the addition 
of a solid yellow lane line), but it has also adopted lane width 
requirements for its LKA testing that match those utilized by Euro 
NCAP. Euro NCAP's ability to successfully conduct the ELK Solid Line 
test demonstrates inherent practicality and should temper Honda's (and 
NHTSA's) previous concerns surrounding inadvertent LKA system 
activation caused by the opposite lane line. Furthermore, NHTSA has 
adopted lane marking length specifications to address commenter 
concerns regarding system lane recognition. The Agency has

[[Page 96052]]

conducted limited testing to observe secondary departures and concludes 
that such assessments are feasible, even considering TRC's concerns 
about the space required for test conduct. The Agency will specify that 
vehicles achieve at minimum of 3 seconds of steady state speed before 
the lane departure is initiated to establish a baseline path from which 
the vehicle will deviate. However, to restrict the required space 
needed for testing, NHTSA will limit the test validity period to the 
first of the following events: (1) the point in time when the SV 
travels more than 0.3 m (1 ft.) beyond the inboard edge of the primary 
lane line separating the SV's travel lane from the lane adjacent to it; 
(2) 5 seconds after the SV has established a heading away from the 
primary lane line and is completely within its original travel lane; or 
(3) 1 second after the SV travels more than 0.3 m (1 ft.) beyond the 
inboard edge of the secondary lane line, where the primary line is the 
line the SV heading's was initially directed towards and the secondary 
line is the line on the opposite side of the SV's travel lane with 
respect to the primary line. The Agency's testing has shown the track 
length required to fulfill these requirements is reasonable.
    Like the other LKA tests adopted for this NCAP update, the SV will 
be driven at 72 kph (44.7 mph) for the secondary departure tests, and 
the lateral velocity of the SV's approach to the lane line will be 
increased from 0.2 to 0.6 m/s (0.7 to 2.0 ft./s) in 0.1 m/s (0.3 ft./s) 
increments. Acceptable LKA performance will be defined by the system's 
ability to prevent the SV from crossing the inboard leading edge of the 
lane line by more than 0.3 m (1.0 ft.). This maximum lane line 
excursion limit will apply for both primary and secondary departures, 
as several commenters requested. NHTSA agrees with Honda that there is 
no need to deviate from the limit adopted for the initial departure, 
since as mentioned earlier, it has real-world practicality. If the 
system's initial intervention satisfies the performance requirement, 
the test will continue to discern whether the vehicle's subsequent 
movement will cause a second LKA intervention. If the LKA system once 
again satisfies the performance requirements for the second 
intervention or does not trigger vehicle movement that necessitates a 
second intervention (i.e., aligns the vehicle with the lane marking(s) 
after the initial intervention) within the validity period, the vehicle 
will receive passing results. Assessments will be performed for 
departures on both sides of the vehicle (i.e., left and right) and the 
same LDW warning requirements adopted for the Agency's other LKA tests 
(which will be defined later) will apply.\394\
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    \394\ Specifically, LDW warning requirements specify a visual 
LDW alert and an auditory or haptic alert (which may be an LKA 
intervention) that must be issued within a tolerance that spans 0.75 
m to -0.30 m (2.5 ft. to -1.0 ft.), and the visual alert must be 
issued prior to, or concurrent with, the LKA intervention.
---------------------------------------------------------------------------

    While NHTSA agrees in theory with Bosch that an LKA system that 
prevents a lane departure on one side should similarly prevent a lane 
departure on the opposite side such that evaluations for secondary 
departures should be unnecessary, the Agency has an obligation to the 
consumer to confirm Bosch's assumption, particularly since, as will be 
discussed later, the Agency's testing has shown that a vehicle's 
response can vary based on departure direction and lane line type. It 
is NHTSA's hope, however, that most systems are designed to re-center 
the vehicle in the lane after an intervention, as Auto Innovators and 
GM stated, and that systems exhibiting alternative performance will 
undergo design improvements conducive to lane centering. As such, the 
Agency will not end the test after the first lane departure event, as 
FCA suggested, but will instead continue to assess performance after 
the first intervention.
    NHTSA also sees merit in conducting testing to assess secondary 
departures despite commenters' objections that the intent of LKA is for 
the initial intervention to grab the driver's attention so that the 
driver intervenes to prevent a secondary departure. While the 
commenters' perspective regarding the main purpose of LKA systems may 
be accurate, the Agency maintains that an inattentive or drowsy driver 
also would likely benefit from a secondary intervention, as the primary 
intervention may cause the driver to suddenly attempt to retake 
control, potentially overcorrecting for steering and/or braking and 
thus imparting additional safety risk. Further, although the Agency 
acknowledges commenters' assertions that a driver monitoring system may 
aid an incapacitated driver, NHTSA is not considering evaluations for 
such technology as part of this effort. As will be discussed later in 
this notice, such systems may be considered for adoption in NCAP in the 
future at such time when the research has been completed and objective 
test procedures are available.
6. Appropriate Lateral Velocities for LKA
    In its 2022 RFC notice, NHTSA cited research it had conducted on 
five model year 2017 vehicles to study the effect of increasing lateral 
velocity on LKA system performance.\395\ For this study, the Agency 
used a slightly modified and older version of Euro NCAP's LSS test 
procedure than that discussed previously. Specifically, the Agency 
deviated from the Euro NCAP procedure and increased the lateral 
velocity of the SV's approach towards the lane line from 0.1 m/s to 1.0 
m/s in 0.1 m/s increments (0.3 ft./s to 3.3 ft./s in 0.3 ft./s 
increments).\396\ LKA performance was considered acceptable in 
instances where the SV did not cross the inboard leading edge of the 
lane line by more than 0.4 m (1.3 ft.).397 398
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    \395\ Wiacek, C., Forkenbrock, G., Mynatt, M., & Shain, K. 
(2019), Applying lane keeping support test track performance to 
real-world crash data. 26th International Technical Conference for 
the Enhanced Safety of Vehicles, Eindhoven, Netherlands. Paper 
Number 19-0208.
    \396\ A robotic steering controller was used to maximize the 
repeatability and minimize variability associated with manual 
steering inputs.
    \397\ At the time of testing, an older version of Euro NCAP's 
LSS test procedure stipulated a lane keep assist assessment 
criterion of 0.4 m (1.3 ft.) for the maximum excursion over the 
inside edge of the lane marking. European New Car Assessment 
Programme (Euro NCAP). See Assessment Protocol--Safety Assist, 
Version 7.0 (2015, November).
    \398\ Wiacek, C., Forkenbrock, G., Mynatt, M., & Shain, K. 
(2019), Applying lane keeping support test track performance to 
real-world crash data. 26th International Technical Conference for 
the Enhanced Safety of Vehicles, Eindhoven, Netherlands. Paper 
Number 19-0208.
---------------------------------------------------------------------------

    An analysis of the five tested vehicles identified performance 
differences between the vehicles depending on the lateral velocity used 
during the test. Some vehicles only provided a steering response at 
lower lateral velocities while others continued to produce a steering 
input as the lateral velocity increased. As will be discussed further 
in a subsequent section, the maximum excursion over the lane marking 
after an LKA activation was also found to be inconsistent, particularly 
as lateral velocity increased.
    Additional LKA tests were run on six model year 2019 vehicles.\399\ 
For each model, vehicle response to solid white and dashed white lines 
was assessed for both left and right departure directions. The same 
lateral velocities as those used in the model year 2017 vehicle tests 
mentioned previously were used in the model year 2019 testing. Findings 
from this testing were similar.
---------------------------------------------------------------------------

    \399\ Reports for these tests can be found in the docket for 
this notice.
---------------------------------------------------------------------------

    At the time of publication of the March 2022 RFC, to represent

[[Page 96053]]

unintended lane departures (i.e., not an intended lane change), Euro 
NCAP's LSS protocol specified use of a range of lateral velocities from 
0.2 to 0.5 m/s (0.7 to 1.6 ft./s) for its LKA and Road Edge recovery 
tests and a range of lateral velocities from 0.3 to 0.6 m/s (1.0 to 2.0 
ft./s) for its Emergency Lane Keeping--Oncoming vehicle and Emergency 
Lane Keeping--Overtaking vehicle tests.\400\ Given the Agency's 
findings from its research testing, NHTSA requested comment on whether 
it should consider adopting a combination of the two lateral velocity 
ranges specified by Euro NCAP for unintended lane departures, 
specifically 0.2 to 0.6 m/s (0.7 to 2.0 ft./s), for inclusion in 
NHTSA's LKA evaluation to encourage the most robust LKA system 
performance.
---------------------------------------------------------------------------

    \400\ European New Car Assessment Programme (Euro NCAP) (July 
2019), Test Protocol--Lane Support Systems, Version 3.0.2.
---------------------------------------------------------------------------

Summary of Comments
    In support of combining and/or aligning tested lateral velocities 
to 0.2 to 0.6 m/s (0.7 to 2.0 ft./s) were Auto Innovators, Honda, ASC, 
BMW, FCA, HATCI, Intel, and Bosch. Several of these commenters focused 
on harmonization, while others mentioned system robustness.
Combine for Harmonization
    Honda asserted that the lateral velocities should be consistent 
when test procedures are designed to represent the same pre-crash 
scenario. As such, the manufacturer supported combining the two ranges 
of lateral velocities. Similarly, FCA commented that aligning with the 
Euro NCAP procedures and combining the lateral velocity range would 
minimize test burden and adequately gauge performance. GM also 
supported the proposal to adopt a lateral velocity range of 0.2 to 0.6 
m/s (0.7 to 2.0 ft./s) to ``simplify testing, provide more consistency 
in testing, and better align with Euro NCAP and limits proposed in SAE 
J3240 Work In Progress (WIP). HATCI supported combining the lateral 
velocities to harmonize with Euro NCAP test procedures, which they 
considered ``widely accepted'' and ``largely representative of the 
field.''
    However, Advocates stated that NHTSA had not provided enough data 
or justification to support adoption of the range of lateral velocities 
specified in the Euro NCAP test procedures. They asked that the Agency 
conduct an analysis using data from event data recorders, NHTSA's crash 
reconstruction databases, naturalistic driving studies, etc. to justify 
that the proposed range is representative of U.S. crashes.
Combine To Ensure System Robustness
    Intel recommended combining the lateral velocity ranges to 
encourage robust LKA performance, since they asserted that NCAP serves 
to ``raise the bar'' and incentivize adoption of the most advanced 
systems. At a minimum, however, the company recommended that NHTSA 
harmonize with Euro NCAP's LKA and Road Edge tests. ASC, which also 
favored combining the lateral velocity ranges, commented that testing 
at higher lateral velocities should improve system robustness and, in 
turn, safety and consumer acceptance. Auto Innovators similarly 
commented that higher lateral velocities will differentiate more robust 
system designs since respective testing will be more difficult to meet. 
However, the group cautioned that 0.6 m/s should be the upper limit 
used for testing, as unintended lane departures may be more difficult 
to distinguish at higher lateral velocities. Finally, CAS suggested 
that the Agency look into combining the two unintended departure ranges 
prescribed by Euro NCAP, as this should ``provide an additional safety 
margin.'' However, like Advocates, CAS also recommended that NHTSA 
conduct additional research to determine whether Euro NCAP's protocol 
best aligns with the crash problem in the U.S.
Other Recommendations
    ZF Group didn't agree that NHTSA should simply combine the lateral 
velocity ranges. They stated that ``both Euro NCAP tests referenced 
were carefully developed and address different scenarios.'' Therefore, 
the group opined that the Agency should align with Euro NCAP's protocol 
(to the greatest extent possible) for both tests. In a similar vein, 
Rivian commented that the 0.6 m/s (2.0 ft./s) lateral velocity is 
appropriate for oncoming vehicle and overtaking vehicle tests because 
they are designed to assess systems that offer increased warning and 
assist thresholds; however, using a 0.6 m/s (2.0 ft./s) lateral 
velocity to assess vehicles in a traditional LKA test where this 
extended capability is not necessary may increase false positives and 
reduce usage of LKA systems. The manufacturer added that systems 
capable of performing well in oncoming vehicle and overtaking vehicle 
tests should receive higher scores.
Response to Comments and Agency Decisions
    As noted at the beginning of this section, when the Agency sought 
comment on this specification, there were two ranges of lateral 
velocities being used in the Euro NCAP suite of ELK, LKA, and Road Edge 
tests: 0.2 m/s to 0.5 m/s (0.7 ft./s to 1.6 ft./s) and 0.3 m/s to 0.6 
m/s (1.0 ft./s to 2.0 ft./s). The Agency proposed to adopt a singular 
range which combined the two Euro NCAP ranges for its LKA testing 
protocol. Newer versions of Euro NCAP's LSS procedure, dated November 
2022 and December 2023, incorporate this combined range for the 
program's LKA and ELK tests. In tandem with the many comments received 
regarding harmonization, Euro NCAP's acceptance of this new range 
further bolsters support for the combined lateral velocity range 
proposed. Thus, NHTSA will adopt the combined range of 0.2 m/s to 0.6 
m/s (0.7 ft./s to 2.0 ft./s) for SV lateral velocities assessed in its 
LDW/LKA tests, with lateral velocities tested in increasing increments 
of 0.1 m/s (0.3 ft./s) to ensure robustness throughout the test range.
    NHTSA notes that harmonization with Euro NCAP for this test 
specification is desired not only by the Agency but by many commenters 
as well. Reasons cited included minimized test burden, simplified 
testing, and use of widely accepted parameters. Manufacturers and test 
laboratories should be familiar with performing LKA-style testing using 
this range of lateral velocities. Further, a move to align test 
procedures to the most reasonable extent possible satisfies a part of 
the BIL, as mentioned throughout this notice.
    Beyond harmonization, as Intel, ASC, and Auto Innovators noted, a 
wider range of lateral velocities will be more difficult to meet and 
should encourage manufacturers to design more robust systems for their 
vehicle models. NHTSA concludes ZF Group's concern regarding the 
differences between test types in Euro NCAP is no longer applicable 
since Euro NCAP has moved toward the 0.2 m/s to 0.6 m/s (0.7 ft./s to 
2.0 ft./s) lateral velocity range for all scenarios that will be 
implemented in NCAP. Also, the Agency notes that both lateral velocity 
ranges used previously in Euro NCAP were initially intended to 
approximate lateral velocities experienced during unintended lane 
departures, lending credence to Honda's comment regarding alignment of 
test specifications under similar scenarios. NHTSA does not anticipate 
a greater

[[Page 96054]]

number of false positive or nuisance activation events from the use of 
a 0.6 m/s (2.0 ft./s) lateral velocity, as Rivian asserted, given that 
it is currently the upper tolerance for LDW testing and has been 
implemented in Euro NCAP's test protocol and the test procedure does 
not simulate a driver actively steering but specifies a trajectory.
    Data gathered by NHTSA for both model year 2017 and 2019 vehicles 
shows that most vehicles failed to adequately intervene during the 0.5 
m/s (1.6 ft./s) and higher lateral velocity tests; this held true for 
both solid and dashed line assessments.\401\ Three vehicles failed to 
offer any LKA intervention at least once (i.e., for either left- or 
right-side departures) at 0.5 or 0.6 m/s (1.6 ft./s or 2.0 ft./s). 
Overall, four of the 11 vehicles did not offer any intervention at 
least once in testing from 0.2 m/s to 0.6 m/s (0.7 ft./s to 2.0 ft./s). 
Notwithstanding, the majority of the 11 vehicles did offer some level 
of lane correction. Notably, one vehicle of the 11 tested successfully 
prevented excessive excursion (greater than 0.3 m, or 1.0 ft.) in each 
of the proposed lateral velocity, departure side, and lane line type 
combinations tested. This result demonstrates that adequate LKA 
performance is achievable between the proposed lateral velocities of 
0.2 m/s to 0.6 m/s (0.7 ft./s to 2.0 ft./s).
---------------------------------------------------------------------------

    \401\ For this testing, one trial was conducted per test 
condition (i.e., combination of lane line type, lateral velocity, 
and departure direction).
---------------------------------------------------------------------------

7. Inboard Lane Line Tolerances and Maximum Excursion Limit
    The Agency sought comment on what lane line tolerances and/or alert 
or intervention timing would be appropriate for LDW and LKA, 
respectively. As mentioned, NHTSA held concerns that the safety 
benefits afforded by LDW technology were diminished because consumers 
were disabling LDW systems to address nuisance alerts stemming from 
excessive activations. To improve consumer acceptance and increase 
safety benefits, NHTSA requested comment in its 2015 RFC notice on 
whether to revise certain aspects of NCAP's LDW test procedure. In 
particular, the Agency proposed to tighten the inboard lane line 
tolerance for its LDW test procedure from 0.75 to 0.3 m (2.5 to 1.0 
ft.). The outboard lane line tolerance would remain -0.3 m (-1.0 ft.) 
from the inside edge of the lane line. Through this, an LDW alert could 
only be issued within a window of +0.3 to -0.3 m (+1.0 to -1.0 ft.) 
with respect to the inside edge of the lane line to pass an NCAP LDW 
trial. This proposal effectively increased the space in which a vehicle 
could operate within a lane before the triggering of an LDW alert.
    The Agency's proposal to revise the lane line tolerances received 
mixed support in 2015. One commenter stated the proposed change was 
``unduly prescriptive,'' and given the typical driver reaction time 
(i.e., 1.2 s) \402\ and target lateral velocity of 0.5 to 0.6 m/s (1.6 
to 2.0 ft./s) prescribed in NCAP's LDW test procedure, an LDW alert 
would have to be issued at a distance of 0.6 to 0.72 m (1.9 to 2.4 ft.) 
to ensure that the majority of drivers could react in time to prevent a 
lane departure. Other commenters stated that some of the more robust 
systems available at the time could comply with the narrower 
specification and that the tolerance reduction should increase the 
required accuracy and quality of lane keeping systems, thus producing 
higher driver satisfaction, and, in turn, system use, compared to those 
systems that meet the current LDW requirements. Another commenter 
agreed that the narrowed lateral tolerance should reduce the issuance 
of false alerts on main roadways but cautioned the Agency that this 
change may not effectively address false alerts on secondary or curved 
roads. On these roads, the commenter stated vehicles not only tend to 
approach within one foot of lane lines, but also may cross them.
---------------------------------------------------------------------------

    \402\ Tanaka, S., Mochida, T., Aga, M., & Tajima, J. (2012, 
April 16). Benefit Estimation of a Lane Departure Warning System 
using ASSTREET. SAE Int. J. Passeng. Cars--Electron. Electr. Syst. 
5(1):133-145, 2012, https://doi.org/10.4271/2012-01-0289.
---------------------------------------------------------------------------

    Given NHTSA's goal of reducing nuisance notifications to increase 
consumer acceptance of LDW systems, combined with several commenters' 
statements that current LDW systems can meet the reduced test 
specification previously proposed, the Agency believed it reasonable to 
propose the reduced inboard lane tolerance of 0.3 m (1.0 ft.).
    Additionally, the Agency also contemplated reduced maximum 
excursion limits of the vehicle beyond the lane line. As previously 
noted, during the Agency's study of LKA system behavior for increasing 
lateral velocity \403\ for a small sample of model year 2017 vehicles, 
LKA performance was considered acceptable for instances where the SV 
did not cross the inboard leading edge of the lane line by more than 
0.4 m (1.3 ft.).404 405 However, the maximum excursions over 
the lane marking recorded during the tests were also compared to the 
measured shoulder width of roads where fatal road departure crashes 
occurred. While the Agency found that most of the roadway departure 
crashes were on roads where the shoulder width exceeded 0.4 m (1.3 
ft.), such that a lane departure could have been prevented if a robust 
LKA system was engaged and functioned properly, the analysis also 
identified roadways where the shoulder width of the roadway was less 
than the 0.4 m (1.3 ft.) maximum excursion limit (e.g., certain rural 
roadways) used in the Agency's testing. The Agency concluded that only 
vehicles displaying robust LKA performance, including at higher lateral 
velocities, would likely prevent the vehicle from departing the travel 
lane on these roadways. Yet, as mentioned previously, NHTSA found that 
many of the assessed LKA systems exhibited inconsistent performance, 
particularly as the lateral velocity was increased. Several vehicles 
exhibited no system intervention, and others exceeded the maximum 
excursion limit as the lateral velocity was increased. Subsequent 
testing for six model year 2019 vehicles revealed similar findings, 
with half of the vehicle models tested showing instances of no LKA 
response even at 0.2 m/s (0.7 ft./s).
---------------------------------------------------------------------------

    \403\ For the Agency's research, the lateral velocity of the 
SV's approach towards the lane line was increased from 0.1 m/s to 
1.0 m/s in 0.1 m/s increments (0.3 ft./s to 3.3 ft./s in 0.3 ft./s 
increments).
    \404\ At the time of testing, an older version of Euro NCAP's 
LSS test procedure stipulated a lane keep assist assessment 
criterion of 0.4 m (1.3 ft.) for the maximum excursion over the 
inside edge of the lane marking. European New Car Assessment 
Programme (Euro NCAP). See Assessment Protocol--Safety Assist, 
Version 7.0 (2015, November).
    \405\ Wiacek, C., Forkenbrock, G., Mynatt, M., & Shain, K. 
(2019), Applying lane keeping support test track performance to 
real-world crash data. 26th International Technical Conference for 
the Enhanced Safety of Vehicles, Eindhoven, Netherlands. Paper 
Number 19-0208.
---------------------------------------------------------------------------

    Since the Agency's analysis showed that most fatal crashes 
identified in its study were on roadways having shoulder widths that 
exceeded the current Euro NCAP test excursion limit of 0.3 m (1.0 ft.), 
NHTSA expressed in its March 2022 RFC notice that adopting the Euro 
NCAP criterion may provide sufficient safety benefits. However, the 
Agency also requested comment on whether an even smaller excursion 
limit may be more appropriate to account for crashes occurring on roads 
with limited shoulder width.
Summary of Comments
Inboard Lane Line Tolerance
    Many commenters were in favor of harmonizing with Euro NCAP's 
current LSS test protocol but did not specify

[[Page 96055]]

whether they also found the lack of inboard lane line tolerances 
specified in these procedures for both passive and active safety 
technologies to be appropriate.\406\
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    \406\ Euro NCAP specifies that vehicles must issue an LDW alert 
prior to -0.2 m (0.7 ft.) from the inner lane edge for all lateral 
velocities up to at least 1.0 m/s (3.3 ft./s) to receive credit for 
an LDW system under the Human Machine Interface (HMI) category. It 
does not dictate an inboard lane line tolerance prior to which an 
LDW system may not issue an alert. Similarly, Euro NCAP does not 
prohibit LKA interventions from occurring too early.
---------------------------------------------------------------------------

    When comparing inboard lane line tolerances for LDW and LKA system 
activation, Advocates suggested the tolerance for LKA should be tighter 
than that for LDW, since LKA involves automatic intervention whereas 
LDW relies on human reaction, which inherently introduces delays. In 
contrast, FCA suggested that the activation tolerance prior to lane 
markings for LKA should be wider than for LDW, since LKA ``is more 
accepted by drivers due to fewer activations'' and ``LKS systems need 
to deal with actuation latencies of steering and/or braking systems.'' 
Rivian agreed with FCA that the LKA tolerance should be slightly higher 
for LKA than for LDW, since LKA systems can have a ``dynamic activation 
range based on lateral velocity toward the line and may activate later 
than this range depending on the speed of the vehicle.''
    Auto Innovators suggested a defined inboard lane line tolerance, 
requesting that the current protocol value, 0.75 m (2.5 ft.), be used. 
The group explained that this will allow the driver ample time to 
intervene prior to the LKA intervention. They also noted that if the 
warning was forced to be issued closer to the lane line, it would 
become redundant with the active safety technology and would no longer 
provide the driver time to respond.
Maximum Excursion Limits
    The Agency also received comments addressing the maximum excursion 
limits permissible for LKA interventions and/or LDW alerts. ASC, Aptiv, 
Auto Innovators, BMW, Intel, Tesla, and Toyota supported an excursion 
limit of 0.3 m (1.0 ft.) over the inboard lane line for both LDW and 
LKA assessments instead of the 0.4 m (1.3 ft.) limit initially proposed 
by NHTSA for LKA. Auto Innovators and Toyota added that this limit was 
justified based on NHTSA's 2018-2019 CISS data, which showed that most 
road departure crashes occurred when the departure distance from the 
lane marking was more than 0.3 m (1.0 ft.), providing reason not to 
reduce the excursion limit. Auto Innovators added that this excursion 
tolerance should be adequate to avoid crashes on road shoulders and 
limit interventions. Tesla stated that adopting a 0.3 m (1.0 ft.) 
excursion limit was sufficient to ensure that LKA systems would 
``maintain tight control over vehicle lateral motion in lane,'' and 
suggested that the Agency maintain this limit for LDW as well.
    IDIADA stated that the Euro NCAP test protocol stipulates that the 
excursion limit (i.e., 0.3 m (1.0 ft.)) is referenced from the outer 
face of the tire to the inner edge of the lane marking. Since the lane 
markings are typically 0.2 m (0.7 ft.) wide, this allows a vehicle to 
have 0.1 m (0.3 ft.) of actual excursion after the lane marking. The 
laboratory stated that the tolerance is provided to improve consumer 
acceptance, essentially preventing system designs that are overly 
intrusive such that they constantly correct vehicle trajectory, but is 
also limited enough to not cause safety concerns. BMW's comments 
closely aligned with those of IDIADA. The automaker explained that, 
with a 0.3 m (1.0 ft.) excursion limit, intrusion onto the shoulder (or 
into another lane) would be 0.15 to 0.2 m (0.49 to 0.66 ft.) given lane 
markings are typically 0.1 to 0.15 m (0.33 to 0.49 ft.) wide, which 
should be adequate to avoid collisions with other obstacles. 
Furthermore, BMW asserted that reducing the excursion limit would 
require earlier system interventions at higher lateral speeds, which 
could increase the number of interventions overall and lead to reduced 
acceptance.
    Intel specifically remarked that the 0.3 m limit was appropriate 
for LDW (in addition to LKA) ``since it covers the flat and elevated 
road edges as a lane border.'' Other commenters supported a 0.3 m (1.0 
ft.) excursion limit specifically for LKA testing. Honda commented that 
a 0.3 m (1.0 ft.) excursion limit was appropriate for LKA, 
acknowledging that the ability of a system to mitigate lane departures 
in the real world is associated with the amount of allowable excursion. 
HATCI and DENSO also recommended a 0.3 m (1.0 ft.) excursion limit for 
LKA, with DENSO remarking that LKA may become ``cumbersome'' when a 
driver must intentionally move into another lane to avoid an obstacle 
because of lane and tire widths if a lower limit is allowed. GM 
expressed support for the 0.3 m (1.0 ft.) limit for LKA, stating that 
such a tolerance was sufficient to prevent roadway departures even when 
shoulder width is limited. However, for LDW, the automaker commented 
that such alerts should not be required until after the referenced 
excursion limit is reached to minimize nuisance alerts and subsequent 
system deactivation.
    Bosch supported an outboard excursion limit of 0.3 m (1.0 ft.) for 
LDW alert issuance and 0.4 m (1.3 ft.) for maximum vehicle excursion 
during LKA intervention but also supported aligning with Euro NCAP's 
tolerances. ZF Group commented that the proposed 0.4 m (1.3 ft.) 
excursion limit for LKA should be sufficient in most situations, but 
for construction areas or those with limited shoulder width, the 
company proposed that LKA should be disabled, and the driver should 
subsequently be notified.
    For LDW, Rivian suggested a maximum range of 0.3 m (1.0 ft.) over 
the lane line and 0.15 m after crossing the outer edge of the lane line 
as an ``acceptable activation range,'' as this would allow for 
different LDW warning settings (e.g., early, normal, late). The 
automaker further commented that 0.3 m (1.0 ft.) is an appropriate 
excursion tolerance for LKA and LDW testing involving lane markings, 
but not a road edge. Also specific to road edge testing, Rivian 
suggested a reduced excursion limit of 0.1 m (0.33 ft.) for systems 
offering road edge detection. For systems not designed for road edge 
detection, the company suggested that if such systems are able to meet 
the 0.1 m (0.33 ft.) excursion limit, they should score higher than 
those that can only meet the 0.3 m (1.0 ft.) limit. Similarly, 
Advocates suggested that different excursion limits are warranted for 
different conditions, stating that Euro NCAP proposes a tighter limit 
for their road edge detection test compared to their single line lane 
tests. Advocates also noted that the maximum excursion limit should be 
based on analysis of real-world data, including crashes and road 
dimensions, in the U.S. Like other commenters, MEMA suggested that the 
Agency should focus on road edge detection if it desires a ``more 
targeted approach'' for the excursion limit.
    CAS stated that a 0.3 m (1.0 ft.) excursion limit over the lane 
marking, as specified by Euro NCAP, was ``unacceptable,'' and 
recommended that the limit ``be reduced to zero to account for roads 
with limited or no shoulder width.'' The group noted that lane markings 
serve to promote safety and often denote the edge of the road, such 
that an excursion of any extent over a lane line may induce a crash 
with other vehicles, pedestrians, or cyclists, or cause the vehicle to 
exit the roadway.
    In response to NHTSA's notation that the 0.3 m (1.0 ft.) excursion 
limit is a Euro NCAP requirement, FCA stated that it supported 
harmonization efforts with other rating programs in general

[[Page 96056]]

but cautioned NHTSA to consider the effect on U.S. driver acceptance 
when considering a reduced excursion limit. The manufacturer suggested 
that any further reduced excursion limit may translate to a more 
intrusive system, resulting in a reduction in acceptance. Finally, TRC 
did not recommend a specific tolerance, but suggested that the 
tolerance adopted for LKA should also be adopted for LDW.
Response to Comments and Agency Decisions
Inboard Lane Line Tolerance
    Based on the lack of definitive data regarding the most appropriate 
LDW alert warning time, and no clear consensus among commenters, the 
Agency has decided to retain its current 0.75 m (2.5 ft.) inboard lane 
line tolerance for LDW activation during LKA testing at this time. This 
tolerance will also apply to LKA engagement. Neither an LDW nor LKA 
intervention shall occur when a vehicle is farther than 0.75 m (2.5 
ft.) from the inboard edge of the lane line. NHTSA reasons this 
approach will allow manufacturers the flexibility to design LDW and LKA 
systems to better identify when a driver is actively steering and 
engaged in the driving task to suppress the alert and intervene when 
the turn signal is not in use.
    NHTSA acknowledges that many commenters responding to the March 
2022 RFC supported the whole or partial adoption of Euro NCAP's LSS 
test protocol. In accordance with the BIL mandate, NHTSA seeks to align 
with other global rating programs whenever it is appropriate to do so. 
However, as previously noted, there is no inboard lane line tolerance 
provided for either Euro NCAP testing or for EU regulations regarding 
lane keeping systems. Consequently, if enabled, these systems may 
activate at any time prior to an excursion limit beyond the lane line. 
There is a need to better define when LDW or LKA should be suppressed, 
and an open-ended tolerance will not solve the issue of nuisance alerts 
or inappropriate intervention.
    NHTSA also has concerns with the initially proposed inboard 
tolerance of 0.3 m (1.0 ft.). The Agency is still of the opinion that a 
tightened inboard lane line tolerance would likely deter the excessive 
alerting currently driving consumer dissatisfaction. However, based on 
the comments received, the Agency could also limit a manufacturer from 
issuing a legitimate alert regarding an impending/ongoing lane 
departure, or initiating an intervention, at an appropriate time. Based 
on these concerns, the Agency has decided to retain its current 0.75 m 
(2.5 ft.) inboard lane line tolerance for LDW activation during LKA 
testing at this time. NHTSA may again consider tightening this 
tolerance in the future once system confidence and accuracy improves or 
as additional lane keeping systems (i.e., LCA) are introduced.
Maximum Excursion Limit for Vehicles During LKA Intervention
    The Agency received many comments in support of a-0.3 m (-1.0 ft.) 
excursion limit from the inboard lane line edge for both LDW issuance 
and LKA intervention. In addition to commenter support, the Agency 
notes that adoption of this maximum LKA excursion limit will harmonize 
NHTSA's NCAP test requirement with Euro NCAP's, meeting one of the 
Agency's primary objectives.\407\ As such, NHTSA will move forward with 
the adoption of a maximum vehicle excursion of-0.3 m (-1.0 ft.) for its 
LKA test in NCAP.
---------------------------------------------------------------------------

    \407\ It should be noted that the LDW excursion limit in Euro 
NCAP is-0.2 m (-0.7 ft.).
---------------------------------------------------------------------------

    The Agency agrees that the ideal amount of allowed vehicle 
excursion beyond a lane marking would be zero, as CAS suggested. 
However, NHTSA is concerned that requiring the vehicle to remain solely 
between the lane lines, particularly at higher lateral velocities, may 
result in a potential increase in nuisance alerts and/or excessive 
activations, which could result in greater system deactivation. IDIADA 
and BMW noted that an excursion limit of-0.3 m (1.0 ft.) from the 
inboard lane line edge translates to anywhere from 0.1 m (0.3 ft.) to 
0.2 m (0.6 ft.) of vehicle encroachment into the adjacent lane or 
shoulder. Given this, combined with the data supplied by Auto 
Innovators and Toyota showing that the departure distance from the lane 
marking for most road departure crashes was greater than 0.3 m (1.0 
ft.), NHTSA agrees with GM that this excursion allowance should be 
sufficient to prevent roadway departures, even on roads where shoulder 
width is limited. NHTSA also reasons that the adopted approach should 
balance consumer acceptance difficulties with real-world benefit.
    Further, NHTSA's model year 2017 and 2019 LKA testing demonstrated 
that compliance with this excursion limit is achievable, even up to 
lateral speeds of 0.6 m/s (2.0 ft./s). Specifically, two of the total 
11 vehicles tested were able to comply with an LKA excursion limit of-
0.3 m (-1.0 ft.) at least once in a 0.6 m/s (2.0 ft./s) test. Three 
additional vehicles fell between the-0.3 m (-1.0 ft.) and-0.4 m (-1.3 
ft.) limit at least once at this upper lateral velocity, demonstrating 
that some vehicles came within inches of achieving satisfactory 
performance during a trial.
    Finally, NHTSA will adopt the same maximum excursion limit of-0.3 m 
(-1.0 ft.) over the inboard lane line for LDW alert issuance. As 
previously discussed, for vehicles with LKA, LDW will become part of an 
expected LKA activation. Thus, maximum excursion tolerance of these 
lane keeping technologies will match, as TRC requested. NHTSA notes 
that the current LDW test procedure allows activation of LDW within the 
same tolerance range adopted (0.75 m to-0.3 m, or 2.5 ft. to-1.0 ft.).
8. LDW Alert Modalities and Requiring an LDW Alert During LKA 
Intervention
    As part of NHTSA's March 2022 RFC notice, the Agency sought comment 
on whether it should award LDW credit to vehicles equipped with LDW 
systems that provide a passing alert, regardless of the alert type 
issued, or whether there are certain LDW alert modalities (such as 
visual-only warnings) that it should consider unacceptable when 
determining whether a vehicle meets NCAP's performance test criteria. 
NHTSA also asked whether it should consider only certain alert 
modalities (such as haptic warnings) acceptable because they may be 
more effective at re-engaging the driver and/or have higher consumer 
acceptance. Finally, NHTSA questioned whether it was necessary to 
require that an LDW alert, designed to re-engage the driver, be issued 
when an LKA system is activated, since these systems are designed to 
intervene and provide steering and/or braking to prevent unintentional 
lane departures (e.g., when a driver is distracted).
    The Agency's questions stemmed in part from concerns (similar to 
those raised for FCW) that LDW systems providing only a visual alert 
may be less effective than systems utilizing other alert modalities 
(i.e., auditory or haptic) in medium or high urgency situations.\408\ 
NHTSA notes that results from a large-scale telematics-based study 
conducted by UMTRI on LDW usage \409\ raised questions as well. As

[[Page 96057]]

part of this effort, researchers investigated driver acceptance of LDW 
alerts in vehicles providing auditory-only alerts and in vehicles where 
the driver had the option to select between either an auditory or 
haptic alert. When the latter was available, the study found the driver 
selected the haptic warning 90 percent of the time; when this setting 
was chosen as the preferred alert setting, the driver turned the LDW 
system `off' 38 percent of the time. Thus, the LDW system was not 
providing alerts. For the system that only issued an auditory warning 
with no option for haptic alerts, LDW functionality was turned `off' 71 
percent of the time. Based on the findings from UMTRI's research, NHTSA 
tentatively concluded that haptic alerts improve driver acceptance of 
LDW systems.
---------------------------------------------------------------------------

    \408\ Lerner, N., Robinson, E., Singer, J., Jenness, J., Huey, 
R., Baldwin, C., & Fitch, G. (2014, September), Human factors for 
connected vehicles: Effective warning interface research findings 
(Report No. DOT HS 812 068), Washington, DC: National Highway 
Traffic Safety Administration.
    \409\ Flannagan, C., LeBlanc, D., Bogard, S., Nobukawa, K., 
Narayanaswamy, P., Leslie, A., Kiefer, R., Marchione, M., Beck, C., 
and Lobes, K. (2016, February), Large-scale field test of forward 
collision alert and lane departure warning systems (Report No. DOT 
HS 812 247), Washington, DC: National Highway Traffic Safety 
Administration.
---------------------------------------------------------------------------

    The Agency's December 2015 notice also addressed the issue of 
drivers choosing to disable their vehicle's LDW system.\410\ In that 
notice, the Agency referenced several studies finding that LDW system 
disablement arose from frequent false activations. In response to these 
findings and concern over diminished safety benefits due to consumer 
dissatisfaction with LDW systems, the Agency solicited comment at that 
time as well on whether it should award NCAP credit only to LDW systems 
that issue haptic alerts. NHTSA opined that haptic alerts may be viewed 
as less of a nuisance by consumers, offering greater consumer 
acceptance compared to auditory alerts and potentially improving the 
effectiveness of LDW alerts because of less frequent system 
disengagement. However, commenters responding to the December 2015 
notice generally did not support a requirement for a specific warning 
type, with most suggesting the Agency should not require a specific LDW 
alert modality to promote system availability across a larger number of 
vehicles and afford flexibility to manufacturers so they may optimize 
human-machine interface (HMI) designs for a growing suite of ADAS.
---------------------------------------------------------------------------

    \410\ 80 FR 78522 (Dec. 16, 2015).
---------------------------------------------------------------------------

Summary of Comments
    Similar to FCW and BSW, comments received on the allowable alert 
types for LDW systems were varied. Some respondents recommended the 
Agency impose no restrictions on alert types, a few recommended certain 
alerts should be unacceptable, several requested additional 
requirements for certain alert modalities or multi-modal modalities, 
and others promoted a specific alert type. Commenters also provided 
mixed recommendations on which type of alert, if any, should be issued 
in the event a vehicle's LKA system intervenes to prevent a lane 
departure.
Allow All Alert Types
    Those in favor of allowing any type of LDW alert during Agency 
testing included Auto Innovators, Honda, IDIADA, HATCI, Intel, Rivian, 
Bosch, and an anonymous public commenter.
    Auto Innovators, citing a lack of evidence that one alert type is 
more effective than another, stated that NHTSA should pursue a 
technology-agnostic approach to allow manufacturers to pursue designs 
preferred by their customers. A public commenter agreed. Rivian 
stressed that the alert type is often a subjective preference and 
although many drivers prefer haptic warnings, not all do, and those 
that don't should be able to purchase vehicles that have alerts suiting 
their preference.\411\ Further, the automaker opined that NHTSA should 
award credit for any form of alert since all modalities should increase 
the possibility that the driver will become reengaged.
---------------------------------------------------------------------------

    \411\ https://www.regulations.gov/comment/NHTSA-2021-0002-4050. 
See citation 4.
---------------------------------------------------------------------------

    Like Auto Innovators, IDIADA stressed the importance that NHTSA be 
flexible with respect to alert type(s) so that manufacturers have 
greater opportunity to provide real-world benefits, particularly for a 
technology like LDW, which generally has lower consumer acceptance. 
HATCI expressed similar sentiments, stating that ``[current] 
flexibilities allow industry to optimize and adjust the alerts based on 
the multitude of ADAS technology installed, the interaction between the 
technologies, and research and development findings.'' The manufacturer 
warned that restricting system alerts to specific modalities may limit 
future alert strategies and have unintended consequences as ADAS 
technology evolves and other systems are introduced. Auto Innovators 
suggested that the Agency should encourage manufacturers to develop the 
most effective systems, which may involve a suite of multimodal alerts 
and not simply a single modality type. Similarly, Honda noted that 
differences in effectiveness and consumer acceptance stemming from the 
use of various alert approaches cannot be captured based solely on 
alert modality and therefore restricting the alert types would not be 
justifiable. Intel stated that modality should not be restricted 
because credit should be based on alert effectiveness (i.e., an alert 
resulting in passing performance is effective, regardless of the alert 
modality type). Finally, noting that system reliability is a factor in 
consumer acceptance of LDW systems, not just warning type, Bosch also 
remarked that any alert modality type should be accepted for credit.
Restrict Alert Types
    A few commenters recommended that the Agency award credit to 
certain alert types and not others. Aptiv and ASC encouraged the Agency 
to restrict auditory alerts to improve consumer acceptance and usage. 
Both entities cited UMTRI's findings (referenced in the March 2022 RFC 
notice and again above) that 90 percent of test participants opted for 
haptic alerts over auditory alerts, and when an auditory alert was the 
only option, the LDW system was turned off 71 percent of the time.
Add Requirements to Visual Alerts or Require Multiple Modalities
    Other commenters suggested that certain alert types may be 
acceptable, but only if they meet certain requirements or are paired 
with a second alert modality.
    DRI suggested that the Agency discontinue the acceptance of visual 
alerts, or alternatively, prescribe minimum characteristics for such 
alerts (i.e., size, color, brightness, location) to help gain the 
driver's attention. The test laboratory contended that in many LDW 
systems, the visual alert, which is typically a telltale in the 
instrument panel that changes color, is ``too small,'' appears in 
``non-attention-capturing colors (e.g., white)'', or is otherwise 
inconspicuous. The company also stated that a distracted driver's gaze 
would likely not be forward-looking, such that a visual alert located 
in the instrument panel would not be helpful like an auditory or haptic 
alert would be to capture the driver's attention. DRI further stated 
that a visual LDW alert is often intended to be an indicator to a 
driver regarding the ``real'' alert, which may be auditory or haptic, 
such that it serves to convey visually to the driver why they are 
hearing or feeling, rather than the visual alert being a warning in and 
of itself. As such, the laboratory opined that visual LDW alerts are 
not effective at alerting the driver unless they are combined with an 
auditory or haptic alert. Toyota and AAA expressed similar comments.
    Toyota noted that a visual-only LDW alert may not be effective for 
a distracted or drowsy driver. Accordingly, the manufacturer 
recommended that an LDW system

[[Page 96058]]

should be required to have two different warning modalities--visual 
plus either haptic or auditory, as research has shown that these 
warning types elicit essentially equivalent drivers' response 
times.\412\ AAA recommended that any visual alert also be accompanied 
by a haptic alert. GM contended that multimodal (e.g., visual plus 
directional auditory or directional haptic) alerts are necessary for 
`imminent crash alerts', but visual-only alerts are acceptable for 
`cautionary crash alerts' to limit instances of drivers turning off LDW 
systems due to alert annoyance. That said, the manufacturer opined that 
credit for LDW alerts in NCAP testing should only be provided for 
multimodal alerts that include both a visual and haptic or auditory 
alert. Like DRI, GM also suggested that the Agency impose additional 
requirements for visual alerts, recommending that visual alerts should 
not only ``help explain the alert to the driver (including alert 
criticality)'' but should also ``be positioned such that they draw the 
driver's attention to the general direction of the crash threat.'' This 
directional requirement, referenced previously, was also suggested for 
haptic and auditory components of multimodal alerts.
---------------------------------------------------------------------------

    \412\ Okuma et al. ``A Study of Tactile Driver Interface using 
Seat Vibrations.'' Transactions of Society of Automotive Engineers 
of Japan. Vol. 39, No. 6, November 2008, p.59-54.
---------------------------------------------------------------------------

    Other commenters also favored additional requirements for visual 
alerts. One anonymous commenter recommended that such alerts be 
directly visible (in the driver's line of sight) without requiring the 
driver to look down to notice the indicator (e.g., in a heads-up 
display, instrument cluster that is fairly high on the dashboard, 
etc.). Similar to Toyota and AAA, however, the commenter stated that 
visual alerts presented outside of drivers' line of sight could receive 
credit if a separate warning type (e.g., auditory or haptic) is also 
provided. FCA held the same view. The manufacturer, which, like others, 
also mentioned higher effectiveness and improved customer satisfaction 
for audio-visual and haptic-visual alerts, suggested that the visual 
warning should appear in the driver's direct line of sight for dual-
modality alerts to receive credit.
Haptic-Only Alerts
    With respect to haptic warnings specifically, FCA commented that 
the Agency should not limit credit solely to haptic warnings, as 
consumer acceptance of LDW systems in general has improved in recent 
years because of improved line detection capability and overall system 
performance.
    Tesla recommended that NHTSA award credit to systems that issue 
haptic alerts, regardless of whether other alert modalities are 
provided. The manufacturer referenced research from the University of 
Michigan Transportation Research Institute (UMTRI) that cited drivers' 
preference for haptic alerts.\413\ Similarly, IDIADA suggested that 
since haptic warnings have higher consumer acceptance rates, they may 
also offer higher real-world benefits if such systems are less prone to 
deactivation. Advocates favored requiring haptic alerts (to promote 
their adoption) if they improve driver acceptance, as NHTSA stated in 
the RFC Notice.\414\ The group suggested that automakers would still be 
able to implement additional human-machine interface (HMI) designs if 
they chose to. ZF Group suggested that the Agency award credit to 
haptic seatbelt warnings, as their research has shown them to be more 
effective than other alternatives.
---------------------------------------------------------------------------

    \413\ 87 FR 13460.
    \414\ 87 FR 13460.
---------------------------------------------------------------------------

    GM stated that the Agency should award additional credit to their 
Safety Alert Seat (SAS) vibration alerts, and to other haptic alerts 
that can support equivalent rationale.\415\ While TRC noted testing 
concerns with haptic alerts, explaining that alert flags for haptic 
alerts are sometimes difficult to collect due to sensor noise, 
especially for alerts issued from the seat or steering wheel, GM stated 
that SAS vibration alerts are triggered simultaneously with an auditory 
alert by the same ADAS signal and can be detected by various means 
during testing (e.g., voltage readings, vibration sensors, auditory 
microphone, etc.). GM stated SAS alerts allow non-visual crash alerts 
to be detected by hearing-impaired drivers, thus improving 
accessibility. Further, the manufacturer noted that in a large-scale 
telematics-based study funded by NHTSA, SAS alerts, relative to 
auditory alerts, were preferred by drivers and also increased usage of 
the LDW system.\416\ More specifically, for vehicles with SAS vibration 
alerts, drivers left LDW on 62 percent of the time, compared to 29 
percent of the time for vehicles offering only auditory alerts.
---------------------------------------------------------------------------

    \415\ https://www.regulations.gov/comment/NHTSA-2021-0002-3856. 
See Appendix 2 for rationale and supporting data.
    \416\ DOT HS 812 247.
---------------------------------------------------------------------------

Weight Alert Credit Depending on Type
    A few commenters suggested that different scores or ratings should 
be assigned to the various alert modalities. Rivian suggested that 
higher scores be assigned to systems proven to be more effective. 
Specifically, it recommended that the Agency should increase ratings 
for vehicles having alerts comprised of additional modalities beyond a 
visual cue but stated that vehicles offering visual-only alerts should 
not be penalized with a test failure. Likewise, ZF Group also 
recommended that NHTSA provide higher scores for alert types that 
reduce driver reaction time compared to other types. Along similar 
lines, citing both increased effectiveness and consumer acceptance for 
haptic alerts, one public commenter suggested that NHTSA reserve full 
credit for systems that offer haptic alerts, or which combine haptic 
alerts with visual or auditory warnings, and award partial credit to 
those systems that issue only a visual or auditory alert.
Other General Topics on LDW Alerts
    The Agency received a few other general comments surrounding LDW 
alerts. One public commenter suggested that an LDW alert issued 
simultaneously with an LKA intervention should also receive credit. GM 
stated that NHTSA should only assess LDW functionality in cases where 
LKA fails to keep the vehicle in the lane per the test procedure 
requirements (regardless of whether the Agency maintains LDW as a 
separate assessment or integrates LDW assessments into an LKA test 
procedure). In such cases, the automaker recommended requiring a visual 
and non-visual alert, as mentioned previously.
    Advocates recommended that the Agency expedite additional research 
on HMI to identify alert modalities and designs that are most effective 
at reengaging the driver and ``eliciting a safe, timely, and accurate 
response.'' The organization suggested there may be further benefit 
realized from standardizing alerts, especially for drivers that use 
multiple vehicles. Contrary to this, HATCI favored flexibility with 
respect to alert types. The automaker mentioned that it supports 
adopting processes and/or performance-based methods developed by 
organizations such as SAE's Human Factors committee to evaluate alert 
effectiveness to not limit future alert strategies for new ADAS 
technologies.
Requiring an LDW Alert During LKA Intervention
    Several commenters, including AAA, AASHTO, Advocates, CAS, GM, 
Honda, Intel, ZF Group, and a public commenter, agreed that the Agency 
should specify that an LDW alert must be issued even when LKA is 
activated,

[[Page 96059]]

mainly because they reasoned that re-engaging the driver was important. 
CAS suggested that an LDW alert could inform the driver that either the 
LKA system has failed to respond, or the intervention required exceeded 
the system's capabilities such that the driver's response is required. 
AASHTO commented that the alert would serve to let the driver know the 
LKA system was intervening and that the vehicle was not altering its 
trajectory due to weather or road conditions. Similarly, AAA opined 
that the alert could serve to ensure the system intervention was not 
misinterpreted as a system malfunction. Intel requested some type of 
warning, explaining that it is preferable for a driver to become aware 
and respond during a lane departure event. IDIADA expressed that it was 
appropriate to issue an LDW alert in ``safety critical scenarios,'' 
\417\ but not for other LKA interventions.
---------------------------------------------------------------------------

    \417\ IDIADA defined ``safety critical scenarios'' as lane 
departure scenarios with a risk of road departure or a collision 
with other vehicles.
---------------------------------------------------------------------------

    Honda specifically mentioned that the system should issue a visual 
alert to best balance consumer acceptance and system effectiveness 
(i.e., safety benefits). That said, the automaker, along with many 
others noted below, asserted that LKA systems inherently provide a 
haptic alert when they move the steering wheel to actively prevent lane 
departures. GM also recommended issuance of a visual alert to limit 
driver nuisance and subsequent system deactivation. The manufacturer, 
like others, asserted that it may be beneficial to let the driver know 
that the LKA system has been activated, but this should be communicated 
via a visual alert, and additional non-visual alerts should not be 
required unless the LKA intervention is insufficient to prevent the 
driver from crossing the lane line. In such instances, GM recommended 
that a flashing visual alert should be used, along with an auditory or 
haptic alert. ZF Group suggested that an alert should be issued to the 
driver when LKA is activated, but that this alert should be different 
than an LDW warning to limit driver confusion.
    Many other commenters, including Auto Innovators, BMW, Bosch, FCA, 
HATCI, Rivian, Subaru, Tesla, and Toyota, objected to NHTSA requiring 
an LDW alert in the event of LKA activation. Bosch asserted, similar to 
Honda, that an additional LDW alert would be redundant as a warning to 
the LKA intervention. Similarly, Rivian explained that the steering 
and/or braking from the LKA intervention effectively alerts the driver 
to the fact they are drifting from their lane. The company further 
stated, and Toyota agreed, that LDW alerts should only be issued to 
warn the driver if the LKA system fails to prevent the vehicle's 
departure from the lane. Toyota, Tesla, and Auto Innovators maintained 
that frequent LDW alerts can be annoying to drivers, with Tesla adding 
this is especially true for those that may actually be alert and 
intentionally drifting to prevent a hazard or for an upcoming turn. As 
such, the three commenters asserted NHTSA must find the right balance 
between LDW and LKA to realize the highest benefits.
    Other commenters, including BMW, FCA, and Subaru, also stated that 
an LDW alert is not needed if LKA operates. Subaru and BMW, along with 
Auto Innovators, indicated, like Rivian, that steering assistance 
(Subaru) and/or braking (BMW) from an LKA system should serve as an 
effective alternative to a haptic LDW alert. Subaru pointed to Euro 
NCAP's 2016-2018 LSS protocol, which recognized LKA steering as a 
replacement for an LDW haptic alert, and BMW directed the Agency to EU 
regulations, which also aligned.\418\
---------------------------------------------------------------------------

    \418\ Commission Implementing Regulation (EU) 2021/646 of 19 
April 2021 laying down rules for the application of Regulation (EU) 
2019/2144 of the European Parliament and of the Council as regards 
uniform procedures and technical specifications for the type-
approval of motor vehicles with regard to their emergency lane-
keeping systems (ELKS) [2021] OJ L133/31, Sec.  3.5.3.1.2.
---------------------------------------------------------------------------

Response to Comments and Agency Decisions
    Many of the comments submitted to the Agency's most recent RFC 
notice on acceptable LDW alert types echoed those received previously 
in response to the Agency's 2015 RFC notice. Namely, most respondents 
were concerned about consumer dissatisfaction with LDW alerts. Thus, 
they favored an alert requirement that is not prescriptive with respect 
to the type of alert modality so that alerts may be optimized for 
consumer preferences. Many also cautioned the Agency that requiring an 
LDW alert during an LKA intervention may exacerbate existing consumer 
acceptance issues for LDW and LKA systems.
    Considering the comments received, the Agency has decided to 
require a visual LDW alert for the Agency's LDW/LKA tests; the LKA 
intervention itself will serve as a secondary haptic alert component. 
In addition, at the manufacturer's option, other auditory or haptic 
alert signals may be provided to the driver to warn of an impending 
lane departure. To pass the LDW requirements for the LKA tests, no 
alert component may be issued before the lateral position of the 
vehicle, represented by a two-dimensional polygon,\419\ is within 0.75 
m (2.5 ft.) of the inboard edge of the lane line (i.e., the line edge 
closest to the vehicle when the lane departure maneuver is initiated), 
and the visual LDW alert component and haptic LKA intervention must be 
issued before the lane departure exceeds 0.3 m (1 ft.). In addition, 
the visual alert must be issued prior to, or concurrent with, the start 
of the LKA intervention.
---------------------------------------------------------------------------

    \419\ The two-dimensional polygon is defined by the vehicle's 
axles in the X-direction (fore-aft), the outer edge of the vehicle's 
tire in the Y-direction (lateral), and the ground in the Z-direction 
(vertical).
---------------------------------------------------------------------------

    NHTSA generally agrees with commenters who stated visual alerts, 
which tend to be more inconspicuous, may best balance consumer 
acceptance and, thus, system effectiveness (i.e., they limit driver 
annoyance and subsequent system deactivation) at low lateral velocities 
when the LKA system should be capable of providing the correcting 
action. In these situations, visual alerts are informational as they 
can convey to the driver that the LKA system is intervening. As some 
respondents stated, without this confirmation, the driver may not know 
whether the system is malfunctioning or whether some other condition, 
such as poor weather or road conditions, is altering the vehicle's 
path. This rationale serves as the basis for a visual alert component 
requirement. However, the Agency also agrees NHTSA should not dictate 
additional specifications for the required visual alert beyond the 
timing requirements mentioned previously. The Agency does not find it 
necessary to impose additional visual alert requirements, such as those 
relating to color, brightness, or location as requested by DRI and GM, 
because it does not wish to limit design flexibility. Additionally, 
manufacturers may choose to issue a visual alert that becomes 
escalatory (e.g., flashing) in nature after some point, as GM 
suggested, but this is not required.
    Additionally, NHTSA will consider the LKA intervention itself to be 
a haptic alert, as several commenters requested. An LKA intervention 
that is clearly related to the lateral control of the vehicle and is 
noticeable by the driver (e.g., notable heading correction that 
prevents the vehicle from exceeding the allowable lateral deviation 
over the inboard edge of the lane line (i.e., 0.3 m (1 ft.)), such as 
that ensuing from steering and/or braking, sufficiently provides 
feedback to a driver such that

[[Page 96060]]

it meets the requirements for a haptic LDW alert. The decision to 
consider an LKA steering intervention to satisfy the requirements for 
an LDW haptic alert aligns with the LDW alert requirements outlined in 
Euro NCAP's LSS test protocol for its LDW tests. This decision also 
reflects the Agency's agreement with respondents who expressed that 
visual LDW alerts are not effective at eliciting a timely response from 
an inattentive driver, when necessary, unless they are combined with an 
auditory or haptic alert. The Agency maintains this position regardless 
of whether a visual alert is positioned in such a way that it is 
directly in the driver's [typical] line of sight.
    While the Agency has prescribed a visual alert component to provide 
information to the driver and a haptic alert component in the form of a 
notable heading correction, it will not stipulate the modality (i.e., 
auditory versus haptic) for any additional LDW alert components the 
manufacturer may wish to include. A separate haptic or auditory LDW 
alert can serve to re-engage the driver in situations where either (1) 
the LKA system has failed to respond or (2) the system may be 
responding, but the intervention that is necessary may exceed the LKA 
system's capabilities such that the driver's response may also be 
required. Toyota's research showed that both warning types elicit 
essentially equivalent response times from drivers, suggesting it is 
not necessary for NHTSA to be overly prescriptive at this time. NHTSA 
also agrees with Honda's assertion that differences in effectiveness 
and consumer acceptance stemming from the use of various alert 
approaches cannot be captured solely based on alert modality and 
therefore restricting acceptable alert types would not be justifiable. 
The Agency also reasons there is merit to Bosch's comment that system 
reliability also factors into consumer acceptance of LDW systems, not 
just warning type, and agrees with Toyota, Tesla, and Auto Innovators 
that it is necessary to find the right balance between LDW alerts and 
LKA interventions to realize the highest safety benefits. Thus, based 
on the lack of consensus on best practices that optimize consumer 
acceptance and system effectiveness, it is the Agency's belief that 
vehicle manufacturers are best suited to optimize LDW alerts for this 
purpose. By allowing manufacturers to choose whether to issue a 
separate auditory or haptic LDW alert during an LKA intervention 
(instead of simply relying on the LKA intervention itself), it will 
help to abate current consumer acceptance issues for LDW and LKA 
systems, a concern cited by many commenters.
    NHTSA will also refrain from prescribing specifications (e.g., 
type, location, decibel level, etc.) for any additional LDW alert 
components at this time, as GM requested. Additional research is needed 
to gauge how certain haptic alert types/locations (e.g., seat belt tug, 
seat/steering wheel vibration) and auditory alert specifications (e.g., 
decibel level) alter system effectiveness before requiring further 
standardization. Should research data become available that better 
describes desirable (or, alternatively, undesirable) characteristics of 
auditory or haptic alert components, the Agency will consider adopting 
specifications for these additional modalities. Similar considerations 
will be made for the required visual alerts. NHTSA will consider being 
more prescriptive for visual alerts if new data suggests there is a 
safety need.
    For haptic alerts specifically (including the LKA intervention and 
any additional haptic alerts), NHTSA will require that manufacturers 
provide additional information to NCAP's test laboratories to detail 
how to accurately record haptic signals without incurring damage to the 
test vehicle. Manufacturers who choose not to provide laboratories with 
such information or opt to provide information that is deemed 
insufficient for data collection, may risk not passing the LKA tests if 
the laboratories are unable to capture the alert flag for a haptic 
signal to ensure it meets the lane line requirements. This additional 
requirement is necessary because alert flags for haptic alerts may be 
difficult to collect due to sensor noise, particularly for alerts 
issued from the vehicle seat or steering wheel. Additionally, this 
additional requirement will not hinder a vehicle manufacturer's ability 
to continue to optimize alerts for current and future technologies as 
they see fit.
    Finally, the Agency is concerned about the limited effectiveness 
and low consumer acceptance of LDW and its potential impact on the 
acceptance of LKA, which has demonstrated higher system effectiveness. 
However, LDW has merit and the updates the Agency is making for its 
lane keeping tests will provide sufficient restrictions to ensure 
nuisance LDW alerts are reduced during real-world driving. NHTSA's 
strategy will ensure higher real-world benefits for lane keeping 
systems overall while also providing manufacturers with the flexibility 
to optimize alerts for consumer preferences and future alert strategies 
for new ADAS technologies, which many commenters requested.
9. User-Configurable Settings for LDW and LKA Tests
    Currently, the Agency requires at least one warning time setting to 
meet the test procedure criteria for LDW testing. NHTSA did not 
specifically request comment on the appropriate settings to use for LDW 
and/or LKA during its NCAP testing, but the Agency received several 
comments on this topic.
Summary of Comments
    For LKA systems with adjustable settings, Honda recommended that 
the Agency evaluate LKA using the middle setting, as it is ``the best 
compromise'' to properly assessing system capabilities. HATCI proposed 
that NHTSA utilize the default system settings during testing. The 
commenter explained that their research has shown that most Hyundai and 
Kia customers do not change ADAS settings after purchasing a new 
vehicle and that changing the settings for testing purposes would 
likely not be most representative of most real-world driving 
situations. The automaker recommended that the Agency conduct a 
similar, fleet-wide study, and use those findings for system settings 
to guide future test procedural changes.
    One public commenter suggested that LDW and LKA systems should be 
required to be default `ON' at the start of every trip. However, Auto 
Innovators suggested that the `Default ON' requirement should be 
changed to `Last saved setting' because `Default ON' has low customer 
acceptance in Europe.
Response to Comments and Agency Decisions
    Aligning with its decisions for FCW and BSW, the Agency has decided 
to set the timing for the LDW alert and LKA intervention to the middle 
(or next latest) setting (if adjustable) during its LDW/LKA 
evaluations, as previously shown in Figure 2. The Agency will not adopt 
the default setting for the LDW alert or LKA intervention, as HATCI 
requested. NHTSA concludes, similar to its earlier decision for FCW, 
that it is reasonable to expect that the setting most preferred by 
drivers would (or rather, should) be the default setting, and this 
setting should generally fall in the middle of the range of driver 
setting preferences that span either earlier or later alert settings. 
Further, NHTSA notes that these system setting configurations align 
with Euro NCAP's LSS test protocol. For LDW and LKA systems having only 
two settings, the Agency will select the later of the two settings to 
align with Euro NCAP's requirements. This test setting will meet

[[Page 96061]]

NHTSA's middle (or next latest) LDW/LKA setting requirement. Lane 
centering functions will also be set to `Off' for all LDW and LKA tests 
in alignment with Euro NCAP's LSS test protocol.
    Tests will also be conducted without cruise control (i.e., 
conventional or adaptive cruise control) engaged. The longitudinal 
speed of the SV will be maintained through manual or robotic control. 
Since cruise control is designed to regulate a vehicle's longitudinal 
movement and there is no vehicle present in the forward path of the SV 
during NCAP's LDW/LKA tests, NHTSA does not expect the use of manual/
robotic control or cruise control to affect how the SV's speed is 
maintained during a test trial. The Agency also does not expect that 
cruise control should impact the SV's lateral movement. That being 
said, NHTSA will conduct testing utilizing only one method of speed 
control to ensure that the performance of one vehicle system (LKA) is 
not affected in any way by the performance of another system (cruise 
control). As mentioned in the BSI discussion, testing with manual or 
robotic control in lieu of cruise control is appropriate since 
consumers may sometimes opt not to use a cruise control feature, 
particularly on non-highway roads.
    Regarding the system settings upon ``key on,'' NHTSA will require 
that the lane keeping technologies (i.e., LDW and LKA systems) appear 
`Default ON' during each ignition/key cycle. While the Agency is not 
prohibiting a disabling function for lane keeping technologies in its 
NCAP evaluation, it is taking steps to reduce the false positive alerts 
and activations that prompt a driver to turn off the systems in the 
first place. Drivers should be able to adjust their system's settings 
to meet their personal preference instead of needing to disengage the 
system altogether.
10. Radius of Curvature
    In its LSS Protocol, Euro NCAP specifies use of a 1,200 m (3,937.0 
ft.) curve and a series of increasing lateral offsets to establish the 
desired lateral velocity of the SV towards the lane line it must 
respond to. In the proposed LKA tests in the March 2022 RFC notice, the 
SV, laterally offset from the center of its travel lane,\420\ is driven 
at a steady velocity of 72 kph (44.7 mph). After a short period of 
steady-state driving, the SV driver (e.g., robot or human input) 
initiates steering to follow a 1,200 m (3,937 ft.) radius curved path 
until the desired lateral velocity towards the lane line is achieved. 
The SV driver then releases the steering wheel. Preliminary NHTSA tests 
have indicated that use of a 200 m (656.2 ft.) curve radius provides a 
clearer indication of when an LKA intervention occurs when compared to 
the baseline tests performed without LKA, a process specified by the 
Euro NCAP LSS protocol. This is because the small curve radius allows 
the SV to establish the desired lateral velocity more quickly, requires 
less initial lateral offset within the travel lane, and allows for a 
longer period of steady state lateral velocity to be realized before an 
LKA intervention occurs. Given the findings from the Agency's testing, 
it sought comment on whether a 200 m (656.2 ft.) curve radius was more 
appropriate for inclusion in NHTSA's LKA test procedure than the 1,200 
m (3,937.0 ft.) radius currently specified in Euro NCAP's protocol.
---------------------------------------------------------------------------

    \420\ The initial lateral offset (based on the vehicle width and 
the desired lateral velocity) of the vehicle from the centerline is 
to ensure the SV is being operated at the desired steady state 
lateral velocity before LKA and LDW operate.
---------------------------------------------------------------------------

Summary of Comments
Agree With Adopting a 1,200 m (3,937.0 ft.) Radius of Curvature
    Many commenters did not support a reduction in curve radius to 200 
m (656.2 ft.) and preferred that the Agency adopt the 1,200 m (3,937.0 
ft.) radius specified by Euro NCAP instead. Commenters voiced concerns 
over potential lack of system intervention, unwanted consequences 
(including a reduction in customer satisfaction and system acceptance), 
and real-world relevance.
    Several commenters, including GM, Toyota, Honda, and Auto 
Innovators, stated that the steering input (e.g., constant larger 
steering angle/torque, higher steering velocities/speeds) and lack of 
steady state lateral velocity (Auto Innovators) required to navigate a 
tight, 200 m (656.2 ft.) curve would appear as an intentional steering 
input, akin to a deliberate lane change or maneuver to avoid roadway 
hazards, not an unintentional drift from the lane, like LKA is designed 
to prevent. In such instances, GM and Auto Innovators asserted that LKA 
systems may not intervene if a small radius of curvature is used during 
NCAP testing. Likewise, Rivian mentioned that although a smaller curve 
radius may make it easier during testing to determine when LKA 
activates, ``a sharper attack angle'' toward the lane line may override 
the LKA system in some vehicles such that the Agency would not observe 
the LKA systems' true capabilities at higher lateral velocities. 
Conversely, Honda stated that adopting a small curve radius for NCAP 
assessments may encourage future LKA system designs to provide 
undesired steering intervention even in situations where drivers 
intentionally input higher steering velocities, such as when the driver 
is intentionally changing lanes without using the turn signal or during 
emergency avoidance maneuvers. The automaker further stated that 
adopting a smaller curve radius for testing purposes may have a 
negative effect on an LKA system's ability to perform its intended 
design function and on consumer acceptance, and in turn, safety 
benefits. Bosch and Subaru asserted that evaluating LKA operation in a 
smaller, 200 m (656.2 ft.) radius curve may prompt a more aggressive 
system intervention if the vehicle deviates from the lane than would 
typically be expected for normal LKA operation, resulting in reduced 
driver comfort, satisfaction, and overall acceptance of LKA. Further, 
Auto Innovators stated that a 200 m (656.2 ft.) curve radius may 
encourage system designs that issue an excessive number of alerts, 
particularly for intentional maneuvers. Auto Innovators indicated this 
would be in conflict with EU regulation 2021/646 on ELKS, which 
``includes a requirement to `minimize warnings and interventions for 
driver intended maneuvers.'' \421\
---------------------------------------------------------------------------

    \421\ Commission Implementing Regulation (EU) 2021/646 of 19 
April 2021 laying down rules for the application of Regulation (EU) 
2019/2144 of the European Parliament and of the Council as regards 
uniform procedures and technical specifications for the type-
approval of motor vehicles with regard to their emergency lane-
keeping systems (ELKS) [2021] OJ L133/31, Sec.  2.2.
---------------------------------------------------------------------------

    Several commenters, including FCA, suggested that the Agency align 
with Euro NCAP's radius of curvature because it better represents real-
world situations. Specifically, Toyota referenced AASHTO's ``A Policy 
on Geometric Design of Highways and Streets'' manual and stated that 
the potential test condition (i.e., navigating a 200 m curve at 72 kph) 
is at the limit of road design and therefore not appropriate.\422\ 
Toyota provided a table showing that a design speed of 70 kph (45 mph) 
corresponds to a minimum radius of 203 m (666.0 ft.). HATCI stated that 
a 200 m (656.2 ft.) radius may be ``a startling input for a vehicle 
driving in a straight lane'' and seemed unrepresentative of a real-
world situation. The group further asserted, like Honda, that such a 
change made to improve testing may have unintended

[[Page 96062]]

consequences in how future derivations of the technology operate. 
Finally, GM pointed to NHTSA's proposed BSI test procedure, which uses 
an 800 m (2,625 ft.) curve for an intentional lane change, in support 
of its opinion that a 1,200 m (3,937.0 ft.) curve more accurately 
represents an unintentional drift out of the lane.
---------------------------------------------------------------------------

    \422\ American Association of State Highway and Transportation 
Officials (AASHTO). (2018). Policy on Geometric Design of Highways 
and Streets (7th Edition), including 2019 Errata. American 
Association of State Highway and Transportation Officials (AASHTO). 
Table 3-7. Minimum Radius Using Limiting Values of e and f.
---------------------------------------------------------------------------

    Several commenters remarked on a variety of other potential 
consequences of adopting a reduced curve radius. For example, Bosch 
remarked that a reduction in radius to 200 m (656.2 ft.) could create 
challenges for test execution. ZF Group cautioned that NHTSA should not 
change the curve radius too drastically, especially without further 
research and consideration for the consequences of doing so, since Euro 
NCAP's LSS protocol resulted from coordinated efforts of both vehicle 
manufacturers and suppliers.
Agree to a Radius of Curvature Between 200 m and 1,200 m (656.2 ft. and 
3,937.0 ft.)
    If a smaller curve radius is preferred, Subaru suggested that the 
Agency adopt an 800 m (2,624.7 ft.) curve radius. Intel commented that 
it would support a reduced curve radius up to 700 m (2,296.6 ft.). 
However, the company cautioned that even this radius may be 
unacceptable since drivers tend to cross lane markings while in a turn, 
which may elicit false positive warnings.
    IDIADA recommended that the Agency use variable radii (between 200 
m and 1,200 m, or 656.2 ft. and 3,937.0 ft.) and the same arc length to 
generate multiple lateral speeds towards the lane line instead of one 
fixed radius and variable arc lengths to generate the lateral speeds, 
as used by Euro NCAP. The laboratory stated that the appropriate 
lateral speed range of 0.1 m/s to 0.6 m/s could likely be generated 
within radii ranging between 200 m (656.2 ft.) and 1,200 m (3,937.0 
ft.).
Agree With Adopting a 200 m (656.2 ft.) Radius of Curvature
    Other commenters, like the ASC, BMW, and CAS, remarked that they 
would support reducing the curve radius to 200 m (656.2 ft.). However, 
BMW stated that the company's support was contingent on there being a 
long period of steady state lateral velocity (also referenced by Auto 
Innovators) to be classified as an unintended lane departure. CAS 
commented that it was ``essential'' to add both curve radii to the LKA 
test procedure to ensure that LKA systems are not designed to a test, 
but instead designed to perform well in multiple real-world conditions, 
especially since such additions would ``impose no additional cost on 
manufacturers.''
General Comments
    Advocates recommended that NHTSA provide comparative performance 
data to show there are benefits of adopting a smaller curve radius 
rather than a 1,200 m (3,937.0 ft.) curve. Advocates also stated that 
``convenience or expediency in testing should not be a substitute for 
robust and accurate protocols.''
Response to Comments and Agency Decisions
    NHTSA is adopting a 1,200 m (3,937.0 ft.) curve radius for SV 
travel paths in its LKA test procedure.
    Based on the comments received, NHTSA concludes a larger (i.e., 
1,200 m (3,937.0 ft.)) curve radius rather than a smaller (i.e., 200 m 
(656.2 ft.)) radius is most appropriate for its LKA testing. In an 
unintentional lane departure, the vehicle would be expected to drift 
out of its lane rather than abruptly turn, as some commenters noted. As 
such, curve radii for unintentional lane departures would be expected 
to be larger than those of intentional lane changes. Along these lines, 
NHTSA finds merit in GM's comment noting the Agency's BSI test 
procedure for assessing intentional lane changes includes a (now-
adopted) curve radius of 800 m (2,625 ft.), a radius significantly 
larger than the 200 m (656.2 ft.) curve radius considered for NHTSA's 
LKA testing, which simulates unintentional lane departures. The Agency 
also sees validity in comments that a smaller curve radius may signal 
an intentional departure due to the necessary steering input, such that 
LKA system designs which take driver intent into account may not engage 
the LKA system as expected. NHTSA also acknowledges the opinion that 
evaluation of LKA capabilities at small curve radii may encourage 
intervention in cases where it is not desired. Besides being 
potentially hazardous, excessive warnings and false activations, in 
addition to aggressive interventions, may deter consumers from enabling 
lane keeping technologies, thus reducing potential benefits, as several 
respondents suggested.
    The Agency will not proceed as IDIADA requested and adopt variable 
(smaller) radii for LKA testing for this upgrade. Although the Agency 
recognizes CAS's concern regarding the use of a single curve radius to 
evaluate LKA system performance, NHTSA also agrees with FCA, Toyota, 
and HATCI that the use of a curve radius of 200 m (656.2 ft.) would be 
aggressive and not necessarily representative when considering real-
world events involving straight roads, even if considering intentional 
lane departures. Adopting smaller curve radii would also deviate from 
Euro NCAP's LSS test protocol for the test conditions adopted by NHTSA. 
As NHTSA aims to harmonize its NCAP with other testing programs 
globally unless there are compelling reasons to do otherwise, it is 
best to mirror Euro NCAP and adopt a 1,200 m (3,937.0 ft.) curve radius 
for SV travel paths in its LKA test procedure at this time.
    Although NHTSA acknowledges the use of a smaller curve radius could 
produce a positive effect on test conduct, NHTSA agrees with Advocates' 
comment that the Agency should first quantify any benefits of adopting 
any curve radius smaller than 1,200 m (3,937.0 ft.). While the Agency 
does not currently have plans to conduct research to compare track 
tests of LDW and LKA to real-world data for different combinations of 
curve radius, vehicle speed, and departure timing, should it choose to 
pursue such testing in the future, NHTSA would consider the need to 
amend the prescribed curve radius or to add additional assessments at 
that time based on the data.
11. Adding a Road Edge Detection Test
    In its March 2022 RFC notice, NHTSA recognized that Euro NCAP has 
adopted a road edge detection test that is conducted similarly to the 
group's LKA tests, but which does not require the use of lane markings. 
The Agency also acknowledged that, while the number of vehicles 
equipped with an ability to recognize and respond to road edges not 
defined with a lane line may presently be low, there are U.S. roadways 
on which this capability could prevent crashes. In a study of fatal 
crashes using 2005 to 2007 National Motor Vehicle Crash Causation 
Survey (NMVCCS) and 2017 Crash Investigation Sampling System (CISS) 
lane/roadway departure cases that was undertaken (1) to classify the 
shoulder type present on the side of the roadway when a vehicle first 
departed its travel lane and (2) to estimate the shoulder width just 
after departure, NHTSA identified fatal crashes where lane markers were 
not present on the side of the roadway where a departure occurred.\423\ 
In these cases, LKA would not provide any benefit unless it had the 
capability to identify the edge of the roadway.
---------------------------------------------------------------------------

    \423\ Wiacek, C., Forkenbrock, G., Mynatt, M., & Shain, K. 
(2019), Applying lane keeping support test track performance to 
real-world crash data. 26th International Technical Conference for 
the Enhanced Safety of Vehicles, Eindhoven, Netherlands. Paper 
Number 19-0208.

---------------------------------------------------------------------------

[[Page 96063]]

    In its March 2022 RFC notice, the Agency also recognized that it 
had received public comments pertaining to the addition of a road edge 
detection test in response to its 2015 RFC notice. Specifically, 
Mobileye recommended that the Agency add not only road edge detection 
scenarios but also scenarios that include curbs and non-structural 
delimiters such as gravel or dirt to reflect real-world conditions and 
crash scenarios more accurately. Similarly, Bosch suggested that NHTSA 
consider introducing road edge detection requirements in addition to 
lane markings since not all roads have lane markings.
    Given the safety need and commenter suggestions, NHTSA sought 
comment in its March 2022 RFC notice on whether it should add Euro 
NCAP's road edge detection test to NCAP for either its LDW and/or LKA 
assessments to address crashes that occur where lane markings may not 
be present.
Summary of Comments
In Favor of Adding a Road Edge Detection Test
    AASHTO, Aptiv, ASC, CAS, GM, Intel, Rivian, Bosch, ZF Group, and a 
public commenter recommended that a road edge detection test be added 
to address roads where lane markings are not present, or the markings 
have faded or are worn. AAA, Advocates, IDIADA, CAS, IIHS, and Toyota 
were also in favor, citing crash frequency and/or severity as a reason 
for inclusion. Advocates expressed support for the test scenario's 
inclusion because the Agency identified road edge departures as the 
third most common lane keeping scenario. Likewise, Toyota pointed to 
NHTSA's 2018 to 2019 CISS data which showed that there were no lane 
markings on the side of departure in approximately 30 percent of road 
departure cases. AAA commented that the possibility of injury and/or 
death increases for roadway departures. IDIADA similarly commented that 
rollovers may stem from roadway departures, therefore making road edge 
detection an important technology, and IIHS remarked that crashes with 
fixed objects are a common occurrence when vehicles leave the road, 
accounting for 32 percent of passenger vehicle occupant fatalities 
(7,253 people) in 2019. IIHS further asserted that ``44 percent of 
these deaths occurred on minor roads, which are more likely than other 
road types to have unmarked road edges.'' The group also stated that 
systems capable of detecting unmarked road edges should also be better 
able to detect obstructed or worn lane lines. GM stated that it 
supported a road centerline plus road edge configuration if NHTSA 
elected to add a road edge detection test to its LKA protocol, since 
such an arrangement would accurately represent a common U.S. roadway 
condition.
    Vayyar did not comment specifically on including a road edge 
detection scenario in NCAP but did state that it is ``highly advisable 
to monitor unmarked road edges'' and noted that this can often be 
achieved using radar.
A Road Edge Detection Test Is Unnecessary
    Two commenters, FCA and Subaru, were not in favor of adding a road 
edge detection test to NCAP's LDW and/or LKA test procedures. FCA cited 
low frequency of single lane lines \424\ in the U.S. relative to other 
countries as a reason not to add a road edge detection scenario. Subaru 
opined that adding a road edge detection test to U.S. NCAP is 
unnecessary, but also stated that NHTSA should conduct further analysis 
of crash data to ascertain the relative frequency of road departures on 
roads with unmarked edges to better gauge representative conditions for 
road edge testing in the U.S.
---------------------------------------------------------------------------

    \424\ The Agency believes FCA's comment was referring to two-
lane, two-direction roadways having only a centerline.
---------------------------------------------------------------------------

Include for LDW, LKA, or both systems?
    AAA, TRC, CAS, Rivian, and ZF Group suggested adding a road edge 
detection test to assess both LDW and LKA systems. Honda expressed 
support for adding a road edge detection test for both LDW and LKA if 
real-world data supports its inclusion, and Advocates indicated support 
for adding the assessment for both technologies if any LKA system 
capable of identifying a road edge also issues an LDW alert prior to 
automatic intervention. ASC suggested that adding a road edge detection 
test for both LDW and LKA would be appropriate, stating that inclusion 
of this test scenario would improve the safety benefits for both 
systems. GM additionally voiced support for adding the test scenario 
assessment for both systems, though they referenced only improved 
safety benefits for LKA. Both Intel and IIHS suggested that it would be 
reasonable to adopt the test for LDW, but stated priority should be 
given to LKA, with IIHS adding that their research has shown that 
drivers are more likely to use LKA compared to LDW,\425\ and LKA 
systems that provide earlier and more frequent steering input to avoid 
lane departures were used more by drivers than LKA systems with later 
and less frequent interventions.\426\ IDIADA stated that since a road 
edge detection test represented a ``safety critical scenario,'' it was 
most relevant for the active technology, LKA.
---------------------------------------------------------------------------

    \425\ Reagan, I.J., Cicchino, J.B., Kerfoot, L.B., & Weast, R.A. 
(2018). Crash avoidance and driver assistance technologies--Are they 
used? Transportation Research Part F: Traffic Psychology and 
Behaviour, 52, 176-190. https://doi.org/10.1016/j.trf.2017.11.015.
    \426\ Reagan, I.J., Cicchino, J.B., & Montalbano, C.J. (2019). 
Exploring relationships between observed activation rates and 
functional attributes of lane departure prevention. Traffic Injury 
Prevention, 20(4), 424-430. https://doi.org/10.1080/15389588.2019.1569759.
---------------------------------------------------------------------------

Adopt Euro NCAP's Test
    AAA, ASC, CAS, GM, HATCI, IIHS, MEMA, Bosch, and Tesla specifically 
mentioned adding Euro NCAP's road edge detection test to the U.S. test 
protocol. IIHS stated that since this test has been part of Euro NCAP's 
protocol since 2018, vehicle manufacturers should be ``reasonably 
familiar'' with it and should already be developing or even 
implementing systems having road edge detection capability. For those 
vehicles lacking this capability, however, Bosch asserted that adding 
this test would drive the availability of these more robust LKA systems 
through the fleet. GM and MEMA stated that road edge excursion limits 
for LDW and LKA should be aligned and standardized with Euro NCAP 
protocols, with GM adding that more stringent limits, adopted by other 
regions, have spurred customer complaints and system disablement due to 
the need for more aggressive systems. However, GM did not support all 
aspects of the Euro NCAP protocol. Specifically, the manufacturer, 
along with Auto Innovators, stated they do not support ``the Euro NCAP 
double road edge lane detection'' because it can cause activation on 
gravel roads, which are common in rural areas in the U.S. Auto 
Innovators also noted that dashed road edges are not common in the U.S.
Additional Specifications Are Necessary
    To improve test-to-test and lab-to-lab repeatability/
reproducibility, Tesla recommended that NHTSA define what constitutes a 
``road edge condition'' and specify how to detect it to minimize 
varying interpretations. Auto Innovators and Toyota also sought 
clarification regarding the road edge test conditions, further stating 
that selection of a road edge should be supported by validation testing 
using vehicles that are already equipped with LDW/LKA technology that 
permits road edge detection. The commenters asserted that, unlike lane

[[Page 96064]]

markings, which can be clearly defined (e.g., length, width, color, 
etc.), road edges have no quantitative definition. Auto Innovators 
added that systems must therefore use artificial intelligence to 
compare and classify how similar a captured camera image is to ``pre-
learned'' road edges. Like Tesla, Auto Innovators expressed concern 
regarding repeatability and reproducibility issues during testing if 
the road edge is not clearly defined.
    Toyota requested that NHTSA base selected road edge test conditions 
on real-world U.S. roadways, which through a review of 2009 NASS-CDS 
cases, showed brush, curbs, and dirt as the three primary surfaces 
involved in road departure crashes.\427\ HATCI also stated that NHTSA 
should select a ``field-representative'' road edge that shows the 
highest safety need and suggested that road owners and vehicle 
manufacturers could work together to develop road edge specifications 
(e.g., materials, shoulders, straightness, etc.) so that vehicles may 
more easily identify them. TRC also stressed the importance of 
specifying the material for the road edge (e.g., gravel, dirt, etc.) 
and recommended a gravel road edge for safe test conduct, especially 
when a steering robot is used during LKA tests and for departures 
exceeding one foot over the road edge. Both BMW and Auto Innovators 
specifically mentioned that they would not approve of scenarios that 
use artificial turf to denote the road edge, with BMW adding that the 
test conditions should closely mirror real-world conditions. Finally, 
Auto Innovators and HATCI requested that NHTSA submit for public review 
and comment road edge specifications prior to inclusion in the 
applicable test procedure(s).
---------------------------------------------------------------------------

    \427\ https://www.regulations.gov/comment/NHTSA-2021-0002-3898. 
See submitted graphics.
---------------------------------------------------------------------------

Response to Comments and Agency Decisions
    Road edge departure crashes are common and may result in rollovers 
or collisions with fixed objects, both of which may have critical 
consequences. However, despite the noted frequency and severity of road 
departures on roads with faded or absent lane markings at the road's 
edge, at this time, NHTSA will not include a road edge detection test 
in its NCAP LDW/LKA test procedure.
    NHTSA recognizes that Euro NCAP currently assesses a vehicle's 
ability to detect a passenger-side road's edge when no lane marking is 
present. This test is performed both with and without a driver-side 
lane marking. However, the test procedure's road edge specifications 
are not well-defined; the road edge may consist of grass and/or gravel, 
or any other approved surrogate. As noted in Annex A of the Euro NCAP 
LSS procedure, there is no artificial road edge with consensus at this 
time. Thus, a variety of real road edges are used, each of which is 
different.
    It is the Agency's belief that every NCAP vehicle should be 
assessed using the same test conditions to promote fairness and 
maintain the program's credibility. To do so, NHTSA would have to 
select a road edge type and more clearly define specifications. 
However, it is currently unclear which single road edge type would be 
most appropriate. As noted by Toyota, a variety of real-world road edge 
types that drivers regularly encounter exist (gravel, curbs, brush, 
dirt, etc.). While the selection of a gravel road edge may be most 
desirable for safe test conduct, as TRC suggested, there is not 
currently data to suggest that this road edge type is the most 
representative.
    While the Agency is not adopting a road edge detection test for 
this NCAP update, given the safety need identified previously to 
address road departure crashes in which a line at the road's edge may 
not be visible or present, as outlined in the NCAP roadmap long-term 
plans, NHTSA will consider enhanced evaluations of LKA systems in NCAP, 
including a road edge detection test at a future time. Prior to 
inclusion of a road edge detection test scenario, NHTSA must determine 
which road edge test condition(s) best represents road edges that 
drivers may encounter in real-world driving conditions, or 
alternatively, that which represents the largest number of crashes and 
thus may offer the largest safety benefit. NHTSA agrees with Bosch's 
comment that adding a road edge detection test would encourage the 
availability of more robust LKA systems throughout the fleet, but the 
Agency does not want to cause unintended consequences by doing so 
before adequate test specifications can be developed, reviewed, and 
adopted. Prior to implementing any future road edge detection 
assessments, NHTSA would consider reducing excursing limits, as 
mentioned in an earlier section, or aligning excursion limits with 
those included in Euro NCAP's test protocol, as GM and MEMA requested. 
It would also conduct testing with then-current vehicle models to 
validate any new test procedure, as Toyota and Auto Innovators 
suggested.
12. Correlating Straight and Curved Road Performance
    NHTSA has only performed test track LKA evaluations using the 
straight road test configuration specified in Euro NCAP's LSS test 
protocol. However, the Agency recognized in its March 2022 RFC notice 
that a significant portion of road departure and opposite direction 
crashes resulting in fatalities and injuries occur on curved roads. A 
review of Volpe's 2011 to 2015 data set showed that for road departure 
crashes where roadway alignment was known, 37 percent of fatalities and 
21 percent of injuries occurred on curved roads.\428\ For opposite 
direction crashes where roadway alignment was known, 30 percent of 
fatalities and 32 percent of injuries occurred on curved roads.\429\
---------------------------------------------------------------------------

    \428\ Roadway alignment was unknown or not reported for 1 
percent of fatal roadway departure crashes and 4 percent of roadway 
crashes where police-reported injuries occurred.
    \429\ Roadway alignment was unknown or not reported for 1 
percent of fatal opposite direction crashes and 2 percent of roadway 
crashes where police-reported injuries occurred.
---------------------------------------------------------------------------

    In NHTSA's study of the 2005 through 2007 fatal crashes from 
NMVCCS,\430\ an analysis of lane departure crashes occurring on curved 
roads \431\ showed that LKA systems would have to provide sustained 
lateral correction (i.e., corrective steering) to prevent the vehicle 
from departing the travel lane. This differs from the smaller 
corrective steering inputs required of LKA systems to prevent lane 
departures on straight roads.
---------------------------------------------------------------------------

    \430\ Wiacek, C., Fikenscher, J., Forkenbrock, G., Mynatt, M., & 
Smith, P. (2017), Real-world analysis of fatal run-out-of-lane 
crashes using the National Motor Vehicle Crash Causation Survey to 
assess lane keeping technologies, 25th International Technical 
Conference on the Enhanced Safety of Vehicles, Detroit, Michigan. 
June 2017, Paper Number 17-0220.
    \431\ It should be noted that the paper identified crashes where 
lane markings were not present on the side of the departure.
---------------------------------------------------------------------------

    In its 2022 notice, NHTSA stated that it is unsure how LKA 
performance observed during straight road trials performed on a test 
track would correlate to real-world system performance on curved roads. 
However, the Agency hypothesized, based on on-road performance testing 
experience of newer model year vehicles, that some current LKA system 
designs include provisions to address lane departures on curved roads. 
The Agency found that some LKA systems engage by providing limited 
operation throughout a curve and thus provide little (if any) safety 
benefit. Conversely, more sophisticated LKA systems maintain engagement 
longer and offer added directional authority throughout a curve. These 
latter systems may provide additional

[[Page 96065]]

safety gains because the driver has more time to re-engage (i.e., 
restore effective manual control of the vehicle).
    Given the real-world need to address lane departure crashes 
occurring on curved roads and the Agency's observations of vehicle 
system performance during on-road driving, NHTSA expressed a desire to 
correlate LKA performance on straight roads to that on curved roads, if 
possible. Specifically, NHTSA sought comment on whether it could 
correlate better LKA system performance at higher lateral velocities on 
straight roads with better curved road performance. The Agency also 
solicited comment on whether it could assume that a vehicle that does 
not exceed the maximum excursion limits at higher lateral velocities on 
straight roads will have superior curved road performance compared to a 
vehicle that only meets the excursion limits at lower lateral 
velocities on straight roads. Finally, the Agency asked whether it 
could assume that the steering intervention while the vehicle is 
negotiating a curve is sustained long enough for a driver to re-engage.
Summary of Comments
Straight and Curved Road Correlation
    There were many commenters who suggested that the Agency could 
correlate better performance on straight roads at higher lateral 
velocities to that on curved roads. Tesla, for one, stated that 
vehicles that afford better straight road performance are often better 
at lane line detection, which typically translates to better lateral 
control in a curve and maintaining tighter and steadier control over 
the vehicle's position within the lane. Another commenter, Rivian, 
suggested that lane line detection, not the ability to handle high 
lateral velocities, was often a problem for LKA systems that offer poor 
performance on curved roads. The commenter recommended that assessment 
of LKA performance should be based on relative lateral velocity to the 
lane line, not absolute lateral velocity. Toyota and Auto Innovators 
opined that there is a correlation, and as such, there would be no need 
to adopt a separate curved road test, but since the entities did not 
have data to support their opinion, they recommended, like others 
below, that the Agency should conduct additional research to 
definitively conclude that a correlation exists. Toyota further 
requested that, if NHTSA was to perform such research, it should 
``clarify whether the target (for LKS performance) is on a constant 
curve, during curve entry, or both.''
    There were also several commenters that agreed the performance may 
be able to be correlated across the two roadway configurations; 
however, a few of these respondents suggested that the Agency conduct 
additional research to confirm the strength of the correlation. Aptiv 
and CAS mentioned that banking and sight line restrictions due to 
changing elevations may affect LKA performance on curved roads, but 
only research to provide comparative test results would indicate how 
much influence these variables have. Bosch stated that an LKA system 
that supports high lateral velocities on straight roads could also 
afford better performance on curved roads because the system should 
likely react faster and earlier, but like Aptiv and CAS, they suggested 
NHTSA conduct additional research to be sure. Although BMW didn't 
suggest additional research, the automaker, like Aptiv and CAS, 
referenced additional factors affecting curved road intervention (i.e., 
accurate detection of road curvature and orientation angle toward the 
lane marking) that could lead to performance variations compared to 
straight roads, thus making a relative comparison difficult. ZF Group 
additionally cited lane detection capability, steering controller and 
torque overlay limits, and vehicle weight as other variables that would 
influence results.
    GM commented that a correlation may be possible under limited 
conditions, such as at certain lateral velocities, but generally, 
curved road performance is influenced by factors like banking (i.e., 
superelevation) (as also mentioned by Aptiv and CAS) and surface 
crowning which can't easily be simulated in a test environment and will 
vary based on design speed, curve radius, etc.
    There were also commenters, including Intel and FCA, who stated 
that a straight road/curved road correlation was not possible. FCA, 
like others, voiced that many factors, including speed, lateral 
position in the lane, and road curvature, affect LKA system performance 
on curved roads, and there is currently no reliable or repeatable test 
method to capture these characteristics.
Equating Excursion at Higher Lateral Velocities on Straight Roads to 
Superior Performance on Curved Roads
    With respect to whether the Agency could assume that those vehicles 
that don't exceed maximum excursion limits at higher lateral velocities 
on straight roads would have superior performance on curved roads 
compared to a vehicle that only meets the excursion limits at lower 
lateral velocities on straight roads, CAS reasoned that was not a valid 
assumption. The group cited influencing factors like sight line 
restrictions, road construction differences (e.g., elevation changes), 
and ``underlying additive lateral acceleration'' that may affect 
relative performance. Bosch agreed that superior performance cannot be 
assumed because reaction time is often different in a curve (i.e., 
often later) and therefore system behavior may vary compared to that 
observed on a straight road.
Driver Re-Engagement
    A few commenters opined on whether NHTSA could assume that LKA-
induced steering intervention while a vehicle is negotiating a curve is 
sustained long enough for the driver to re-engage. Almost all 
respondents said no, that is not a safe assumption. CAS expressed that 
there are too many variables to be considered (i.e., speed, curve 
geometry, the ADAS warnings provided, and the driver response) for such 
an assumption to be made. Intel remarked that the steering intervention 
doesn't end until the vehicle is parallel to the road lane marking 
(with sufficient margin) for a few seconds. However, in sharp curves, 
the commenter noted that the system torque is ``limited and [it] will 
not be comfortable for the driver to re-engage.''
    Unlike the other commenters, BMW stated that the driver would have 
enough time to re-engage, stating that the system intervention will 
last for several seconds as the system attempts to align with the lane 
marking. Likewise, ZF Group stated that corrective steering is provided 
when the system detects it is entering the `intervention zone,' and it 
should be maintained throughout the curve (if the vehicle remains in 
the `intervention zone') until it disengages once the vehicle is 
brought back into the appropriate position. Rivian stated LKA 
intervention should be sustained in a curve until a driver re-engages 
because the consequence of system deactivation in the middle of the 
curve (before driver re-engagement) could be dangerous. The commenter 
further stated that vehicles that disengage prior to reengagement by 
the driver should receive lower scores.
    Unlike the other respondents who said re-engagement either was or 
wasn't possible, Bosch remarked that it is dependent on the system 
design, with some systems providing only a slight correction to the 
heading angle, whereas others guide the vehicle back to the center of 
the lane.

[[Page 96066]]

Adoption of a Separate Curved Road Test
    BMW asserted it was more appropriate to incorporate a curved road 
test than to assess systems at high lateral velocities on straight 
roads since some systems may interpret a fast approach towards the lane 
marking to be an intentional lane change (without use of the turn 
signal) and would suppress an intervention accordingly. Auto Innovators 
also shared BMW's concern (though they did not favor adopting a 
separate curved road assessment) and added that a fast or strong system 
intervention in such instances may affect customer satisfaction, which 
must also be considered in system design. ASC agreed with BMW that 
NHTSA should develop a curved road test rather than attempt to 
correlate performance. Advocates supported incorporation of a curved 
road test in general, since a large proportion of crashes, especially 
road edge departure crashes, occur on curved roads.
    Unlike Advocates, Rivian suggested that NHTSA should not adopt a 
curved road test because most lane departure crashes occur on straight 
roads \432\ and therefore the safety need is not as great for curved 
roads. The manufacturer further asserted, along with IDIADA, that 
drivers tend to be more attentive on curved roads since they know they 
are required to steer. Because of the influential testing variables 
mentioned previously, GM was also not supportive of adopting a curved 
road test, relaying that adding test scenarios that do not accurately 
depict real-world driving conditions may drive LKA system changes to 
meet test requirements that degrade performance for real-world drivers, 
thus compelling drivers to turn systems off. GM further stated that 
Korean NCAP performs a curved road test and there is high variability 
in test results.
---------------------------------------------------------------------------

    \432\ 87 FR 13452 at 13494.
---------------------------------------------------------------------------

    Toyota and Auto Innovators also recommended adopting only a 
straight road test condition at this time. The commenters expressed 
concerns related to repeatability and reproducibility for curved road 
testing, stating that (1) lane departure speed, which is the key input 
to initiate and evaluate LKA system performance, is strongly affected 
by initial lateral offset and yaw angle, and (2) it would be difficult 
to configure the exact same curved lane (i.e., same curve radius, 
clothoid length, banking angle, lane width, etc.) at all testing 
locations, including those used by vehicle manufacturers for NCAP 
performance verification assessments. Similar to GM's assertion 
regarding Korean NCAP, the groups also relayed that Euro NCAP has not 
adopted a curved road assessment because of repeatability concerns.
    Test labs also expressed concerns regarding the feasibility of 
curved road testing, with TRC cautioning that curved road testing 
requires much more space than straight road testing, and as such, 
testing locations are limited. Further, IDIADA stated that curved road 
scenarios are ``extremely difficult to implement.''
Response to Comments and Agency Decisions
    At this time, NHTSA cannot assume that LKA performance on straight 
roads correlates with that expected for curved roads.
    Commenters unanimously agreed that superior performance on curved 
roads could not be assumed for those vehicles that do not exceed 
maximum excursion limits at higher lateral velocities on straight 
roads. NHTSA acknowledges, as several commenters stated, that there are 
vehicle-specific factors like vehicle weight and speed, in addition to 
the vehicle's capability for lane line detection, which may affect LKA 
system performance on curved roads more so than on straight roads. The 
Agency also recognizes commenter concerns surrounding system 
suppression and unintended consequences of abrupt or strong system 
interventions stemming from the high lateral velocities needed to 
simulate curved road conditions on straight roads, both of which 
suggest a correlation is impracticable. Further, the Agency 
acknowledges that most commenters expressed that it is unreasonable to 
assume that an LKA steering intervention is sustained long enough in a 
curve for a driver to re-engage in the driving task. While Rivian 
acknowledged that LKA intervention should be sustained in a curve until 
a driver re-engages because of the consequences inherent to system 
deactivation in the middle of the curve (before driver re-engagement), 
most commenters contended that there are too many variables at play to 
have such assurance, with Bosch stating that it depends on the system 
design, as some systems may only offer a slight heading correction 
whereas others direct the vehicle back into the center of the lane. 
Without such assurance, it would be misguided for the Agency to 
consider a correlation to be a sufficient surrogate for an actual 
curved road assessment.
    Further, commenters provided mixed support for adopting a 
designated curved road test in NCAP. Commenters expressing support 
noted that such a test would be more appropriate to reflect true system 
performance. Those opposed cited testing feasibility concerns, 
specifically limitations posed by space constraints and repeatability 
and reproducibility concerns arising from the need to replicate the 
exact test conditions/curved lane configuration across all testing 
locations. NHTSA acknowledges, as many commenters stated, that there 
are numerous roadway characteristics that can affect curved road 
intervention, including curve radius, elevation changes (i.e., 
superelevation), and sight line restrictions, which are difficult to 
simulate in a test environment, especially in a reliable and repeatable 
manner. It further acknowledges GM's concern that test scenarios that 
don't accurately reflect real-world driving conditions may spur 
degradation in real-world LKA performance, leading to system 
deactivation and a loss of safety benefits.
    In consideration of commenter concerns, the Agency plans to 
initiate a multifaceted curved road research effort. As part of this 
research, NHTSA intends to: (1) review lane and road departure crash 
data to identify curve radii and other roadway variables (e.g., 
superelevation, lane width, etc.), vehicle speed, and departure timing 
(e.g., at curve entry, mid curve, or near curve exit); (2) identify 
other lane departure protocols, or parts of protocols, that may be most 
relevant to real-world road departures, particularly those related to 
curved lanes; (3) identify vehicle models that have LKA systems that 
are designed to prevent lane departures on curved roads; (4) identify 
next generation LKA systems and document expected functionality; and 
(5) perform pilot testing to evaluate potentially suitable curved road 
test protocols. By taking these steps, NHTSA hopes that it will be able 
to develop a test protocol that accurately simulates real-world lane 
departures on curved roads to best address the safety problem. After 
the research is completed, NHTSA will consider these enhanced 
evaluations of LKA systems in NCAP, as noted in the NCAP roadmap long-
term plans.
13. Increasing LKA Test Speed
    In its recent RFC notice, NHTSA noted that a sizeable portion of 
fatal road departure and opposite direction crashes occur at higher 
posted and known travel speeds. As part of its independent analysis of 
the 2011 to 2015 FARS data set, Volpe found that, of those crashes 
where posted speed limits were known, 58 percent of fatal road 
departure crashes and 69 percent of fatal opposite direction crashes

[[Page 96067]]

occurred on roads with posted speeds exceeding 72.4 kph (45 
mph).433 434 Further, the study revealed that speeding was a 
known factor in 33 percent and 13 percent of fatal road departure and 
opposite direction crashes, respectively.435 436 Volpe also 
found that when travel speed was known, 83 percent of fatal road 
departure crashes and 74 percent of fatal opposite direction crashes 
occurred at known travel speeds exceeding 72.4 kph (45 mph).
---------------------------------------------------------------------------

    \433\ Swanson, E., Foderaro, F., Yanagisawa, M., Najm, W.G., & 
Azeredo, P. (2019, August), Statistics of light-vehicle pre-crash 
scenarios based on 2011-2015 national crash data (Report No. DOT HS 
812 745), Washington, DC: National Highway Traffic Safety 
Administration.
    \434\ For data where the travel speed was known, 63 and 65 
percent of the data is unknown or not reported in FARS for road 
departure and opposite direction crashes, respectively. For road 
departure and opposite direction crashes, respectively, 3 and 1 
percent of the posted speed data is unknown or not reported in FARS.
    \435\ Swanson, E., Foderaro, F., Yanagisawa, M., Najm, W.G., & 
Azeredo, P. (2019, August), Statistics of light-vehicle pre-crash 
scenarios based on 2011-2015 national crash data (Report No. DOT HS 
812 745), Washington, DC: National Highway Traffic Safety 
Administration.
    \436\ It was unknown or not reported whether speeding was a 
contributing factor in 7 percent of fatal road departure crashes and 
4 percent of fatal opposite direction crashes.
---------------------------------------------------------------------------

    Since NHTSA did not have data to show that LKA system performance 
at Euro NCAP's current test speed of 72 kph (44.7 mph) would be 
indicative of system performance when tested at higher speeds, the 
Agency requested comment on whether it would be beneficial to 
incorporate additional, higher test speeds to assess the performance of 
lane keeping systems in NCAP, or whether the current test speed is 
sufficient to indicate performance at higher speeds, especially on 
straight roads. Given the findings from NHTSA's LKA testing of model 
year 2017 and 2019 vehicles, which showed differences in LKA 
performance at greater lateral velocities, the Agency also expressed 
concern about LKA performance at higher travel speeds when the vehicle 
first transitions from a straight to a curved road, since lateral 
velocity may be high in those situations.
Summary of Comments
Maintain Current Test Speed
    Many commenters suggested the LKA test speed should remain at 72.4 
kph (45 mph). ASC, BMW, and Bosch commented that the current NCAP test 
speed accurately evaluates LKA performance at higher speeds and that 
increasing the test speed was unnecessary. Auto Innovators agreed that 
performance at the current test speed is indicative of performance at 
higher test speeds, and additionally mentioned that performance at 
lower speeds could also be assured. Similarly, GM stated that the 
proposed 72.4 kph (45 mph) test speed accurately evaluates performance 
at other speeds. HATCI recommended that NHTSA harmonize with Euro 
NCAP's test speed of 72 kph (44.7 mph), as it is representative of LKA 
performance at higher speeds and sufficient to address fatal road 
departure and opposite direction crashes. Similarly, ZF Group agreed 
that the Agency should harmonize with existing protocols to the extent 
possible. FCA expressed that high-speed unintentional lane departures 
occur at lower lateral velocities, and such events would be encompassed 
by the 0.2 m/s lateral velocity in the current 72.4 kph (45 mph) LKA 
test such that no additional speed increase is necessary. On the other 
hand, Advocates expressed that NHTSA must have data to ``indicate 
whether longitudinal velocity is correlated with lateral velocity and 
which of these or their interaction are determining factors in 
assessing performance of LKS systems.'' The organization questioned 
whether testing at a lower longitudinal speed and higher lateral 
velocity is the best way to differentiate between systems having 
different performance.
    TRC, Auto Innovators, and GM referenced logistical concerns for 
higher speed test assessments. TRC stated that if speeds were 
increased, additional lane markings and distance would have to be 
maintained. Likewise, Auto Innovators and GM expressed that longer and 
wider test tracks having additional runoff space would be necessary for 
safe testing at higher speeds, and yet, such testing would yield 
similar results to those obtained at 72 kph (44.7 mph).
Consider Additional Test Speeds
    A few commenters, including Intel and CAS, favored higher test 
speeds to assess LKA system performance. Specifically, CAS asserted 
that higher speed testing would be a better indicator of LKA 
performance. The organization suggested that test speeds should be 
increased until safe performance limits are established, and these 
speed limits should then be communicated to consumers. That said, CAS 
also acknowledged that ``some LKS testing is better than no LKS 
testing.'' Like CAS, one public commenter recommended that the LKA test 
speed be increased to ``ensure accuracy.'' The commenter mentioned that 
most fatal road and lane departure crashes occur at higher speeds, and 
at such speeds, the driver's ability to react and maintain control of 
the vehicle is reduced. IDIADA stated that since LKA system activation 
occurs at speeds of 65 kph (40.4 mph) or greater, the current 72.4 kph 
(45 mph) test speed covers only the lower limit of system intervention. 
As such, the company suggested that the Agency could consider 
conducting testing at speeds up to 120 kph (74.6 mph). MEMA did not 
expressly recommend increasing the LKA test speeds. However, MEMA did 
mention that there is ``no technical barrier to detecting lanes at a 
range that would reliably support higher LKS test speeds.'' Similarly, 
ZF Group mentioned that ``there is no technology concern associated 
with testing at higher speeds.'' Finally, Rivian suggested that NHTSA 
evaluate LKA performance at both higher and lower speeds to better 
assure expected performance.
Response to Comments and Agency Decisions
    As mentioned earlier, NHTSA is adopting a test speed of 72 kph 
(44.7 mph) for its LDW/LKA tests. This test speed aligns with many 
real-world road departure and opposite direction crashes and serves as 
an appropriate starting point for the Agency's newly adopted lane 
keeping tests. The Agency reasons this test speed is also appropriate 
because it further promotes harmonization. It is the same speed used in 
Euro NCAP's LDW, LKA, and ELK tests, which are comparable to those 
NHTSA is incorporating in NCAP.
    Many commenters asserted that LKA performance at a test speed of 72 
kph (44.7 mph) would be sufficient to assure similar LKA performance at 
higher (and lower) test speeds, and therefore, adding additional test 
speeds for NCAP's tests is unnecessary. However, the Agency hesitates 
to agree without additional research testing. It may be true, as 
Advocates suggested, that testing at a lower longitudinal speed and 
higher lateral velocity may not sufficiently differentiate between 
systems that have different performance at higher speeds. In this case, 
higher-speed tests would also be necessary to effectively address the 
safety problem. Conversely, it may be true, as FCA asserted, that a 
72.4 kph (45 mph) LKA test is sufficient to address unintentional lane 
departure crashes occurring at high speeds because these real-world 
crashes occur at lower lateral velocities, such as those already 
included in the Agency's test matrix. Unfortunately, NHTSA does not 
currently have data to indicate whether longitudinal velocity is 
correlated with lateral velocity, as Advocates requested, nor does it 
know the extent to which each of these factors influence LKA

[[Page 96068]]

system performance. It also does not fully understand how driver 
reaction time or the driver's ability to maintain control of the 
vehicle as speed increases may influence overall LKA system performance 
or crash outcomes. As such, more research is needed before NHTSA can 
conclude with certainty whether the adopted LKA test conditions will be 
sufficient to ensure safety benefits at alternative test speeds, or 
whether additional test conditions are necessary. Regardless, because 
of the significant crash problem currently at hand, it is prudent to 
move forward with the adopted 72.4 kph (45 mph) SV speed at this time 
rather than wait for the completion of further research.
    As discussed previously, the Agency plans to review real-world road 
departure crash data as part of a future research effort. NHTSA will 
document the roadway conditions associated with these crashes (e.g., 
posted speed limits, roadway curvature, etc.) as well as other 
influencing factors, such as vehicle speed and lateral velocity. The 
Agency will consider higher speeds in future evaluations as well as 
other logistical concerns posed by commenters (e.g., longer and wider 
tracks).
14. Reducing the Number of Required Test Conditions
    Given the Agency's LKA test procedure currently contains many test 
conditions (i.e., line type and departure direction), NHTSA requested 
comment on whether it is necessary to perform all test conditions to 
adequately address the lane departure safety problem or whether it 
could instead only test only certain conditions to minimize test 
burden. Specifically, NHTSA sought comment on whether it should 
consider incorporating the test conditions for only one departure 
direction if the vehicle manufacturer provides test data to assure 
comparable system performance for the other direction or consider 
adopting only the most challenging test condition(s). If commenters 
preferred the latter, the Agency questioned which test condition(s) 
would be most appropriate.
Summary of Comments
Departure Directions
    NHTSA received several responses on whether it would be sufficient 
to assess LKA performance for only one departure direction (i.e., left 
or right), with both BMW and Auto Innovators suggesting that this could 
be possible. BMW mentioned that their internal assessments evaluate 
performance for both departure directions, so they could provide data 
for the direction the Agency chooses not to assess. However, Auto 
Innovators, GM, and Bosch cautioned NHTSA that identical performance 
cannot be guaranteed for both departure directions since not all LKA 
systems are symmetrical. Auto Innovators recommended that manufacturers 
attest to their vehicles' symmetry if NHTSA was to eliminate testing on 
one side to reduce test burden.
    Bosch maintained that the Agency should still evaluate all 
conditions (e.g., departure directions and lane marking types) to 
ensure system robustness and effectiveness and consistency of test 
results. GM, ASC, and Aptiv agreed with the need to test both 
directions. In a similar vein to that expressed by Auto Innovators and 
Bosch, DRI and TRC also commented that they have observed different 
performance depending on departure direction. As such, TRC encouraged 
NHTSA to assess both directions for all test conditions, but at a 
minimum, both directions for both solid and dashed lines.
Lane Line Types
    Responses received on limiting LKA testing to a specific lane line 
type(s) were varied. FCA and ZF Group asserted that LKA systems should 
afford equal performance regardless of lane line type, while DRI 
claimed that it has observed differing performance for various lane 
lines. GM and Toyota claimed the dashed lane line condition was more 
challenging for LKA systems since cameras detect the contrast between 
the road surface and the lane line paint; however, GM stated that it 
has not seen meaningful performance differences for the various lane 
line types. GM further stated that Euro NCAP reduced the number of lane 
lines assessed starting in 2023 for this reason. Intel suggested that 
the Agency assess LKA performance for only the dashed lane line to 
reduce test burden, whereas, for the reasons stated earlier, Bosch 
recommended assessing all lane line types.
Minimizing Test Burden in General
    In general, Auto Innovators stated that NHTSA should minimize test 
burden by prioritizing those test conditions representing the highest 
real-world risk and harmonizing with other organizations where 
possible. Advocates suggested that NHTSA should determine the number of 
scenarios that are necessary for testing based on whether performance 
in the selected scenarios would be sufficient to address the [targeted] 
safety need. Likewise, Rivian cautioned the Agency not to sacrifice 
coverage of real-world conditions in an attempt to reduce test burden. 
Therefore, the company did not support selecting only the most 
challenging conditions in general, especially since, depending on the 
technology, system types may vary (i.e., some may be camera-only, while 
others may use radar, lidar, or be fused) and may thus have different 
challenges.
    On the other hand, Toyota stated that adopting the most challenging 
conditions, as NHTSA had also suggested, may be a viable solution to 
reduce test burden. As an example, Toyota suggested that if sensing for 
LKA systems becomes more difficult for higher lateral speeds and dashed 
lane lines, then that test condition would be the one adopted. CAS 
agreed with Toyota in sentiment but cautioned, like Advocates earlier, 
that if the most challenging test conditions do not actually encompass 
test conditions that are removed, the Agency risks the possibility that 
manufacturers will design to the test and thus safety benefits will be 
lost.
    It is for this reason (i.e., loss of safety benefits) that IDIADA 
opposed adopting only the most challenging test conditions. The test 
laboratory asserted that LKA systems may be designed to intervene only 
at high lateral speeds, which may be considered ``worst-case,'' but 
won't intervene at lower speeds, which will only further reduce 
consumer acceptance, and thus benefits. IDIADA suggested adopting a 
reduced test matrix (e.g., 0.2, 0.4, 0.6 m/s lateral velocity) or 
introducing a ``GRID approach,'' whereby the manufacturer would provide 
all results for all tests required in the test matrix, but NHTSA would 
only verify testing for a subset of the required test conditions.
    Intel and FCA suggested a similar concept to IDIADA's first 
suggestion, a reduced test matrix. The two entities suggested that, to 
reduce test burden, the Agency should limit the number of lateral 
velocities assessed, with FCA specifying that NHTSA should test the 
minimum and maximum lateral velocities considered. Along these lines, 
Toyota also favored ``efficient'' testing, whereby only those test 
conditions and trials should be performed that are necessary to 
communicate performance to consumers. Like FCA, the automaker mentioned 
if testing one speed can assure performance across a speed range, then 
only that speed should be tested.
    To reduce test burden, GM also favored reducing the number of test 
scenarios, where possible, instead of the number of test runs (as 
proposed separately by NHTSA). The manufacturer stressed that setup for 
a

[[Page 96069]]

different test scenario requires significantly more time than 
conducting additional runs. ASC suggested that NHTSA should not reduce 
the number of test conditions and pointed out that the removal of the 
Botts' Dots test condition inherently presents a reduction. ZF Group 
was supportive, in general, of using manufacturer test data to augment 
NHTSA's results for those test conditions not assessed by the Agency. 
The group commented that this should not affect NHTSA's ability to 
provide an accurate performance assessment for LKA systems.
Response to Comments and Agency Decisions
    Given the comments received, NHTSA has decided to continue testing 
both departure directions (i.e., left and right) and several lane line 
types for its lane keeping performance tests. As mentioned previously, 
the Agency will also incorporate an additional test scenario that is 
similar to Euro NCAP's ELK Solid Line test. With the addition of this 
test, the Agency will conduct LDW/LKA assessments with dashed yellow, 
solid yellow, dashed white, and solid white lines, in addition to 
Botts' Dots. This approach, which adopts two departure directions and 
several common lane line types, should allow the Agency to continue to 
ensure system effectiveness and robustness, as Bosch asserted, as well 
as coherence with test protocols to maintain safety benefits.
    The Agency shares concerns expressed by those commenters who 
contended that system performance may vary for each departure direction 
depending on vehicle symmetry and system robustness. NHTSA has observed 
performance failures in one departure direction but not the other 
during NCAP testing of LDW systems and research testing of LKA 
systems.\437\ While the Agency could use manufacturer data or symmetry 
attestations to limit testing to one departure direction to reduce test 
burden, NHTSA agrees with Bosch that only the Agency's own tests will 
ensure consistency of results for consumers.
---------------------------------------------------------------------------

    \437\ See model year 2019 LKA test data.
---------------------------------------------------------------------------

    The Agency's testing has also shown LDW system failures for a 
particular lane line type but passing results for the others assessed, 
proving, contrary to assertions from several commenters, that 
equivalent performance is not guaranteed. Furthermore, while several 
commenters suggested that NHTSA could conduct assessments for only the 
dashed lane line condition because it is the most challenging for lane 
departure systems, the Agency's LDW data has shown run failures for 
other lane line types as well. Notably, NHTSA has observed LDW run 
failures during Botts' Dots assessments but passing results for all 
runs conducted for the dashed line condition. Additionally, the Agency 
has seen LDW run failures for the solid line conditions and passing 
results for the dashed line configuration for a given vehicle. Similar 
observations were also made during NHTSA's LKA research for each of the 
model year 2019 vehicles tested. For a given lateral velocity, it was 
typically the case that failures were observed for the solid line 
condition but not the dashed line condition or vice versa. The Agency's 
data seems to show, as Rivian asserted, that different lane departure 
system types may have different challenges. As such, there is merit to 
continuing to assess multiple lane line types during the Agency's 
testing.
    Even with the addition of Euro NCAP's ELK Solid Line test, NHTSA is 
taking sufficient steps to reduce test burden by integrating LDW and 
LKA testing and eliminating repeat trials (as discussed next) such that 
it is not necessary to further limit testing to assessments for one 
lane line type, departure direction, or, as Toyota suggested, lateral 
velocity. Only by retaining test conditions representing greater 
coverage of real-world situations will the Agency ensure that it 
continues to address the safety need, as several commenters requested. 
NHTSA also reasons, as mentioned for the other ADAS technologies 
included herein, that pursuing an incremental approach to increasing 
test stringency (i.e., that realized by increasing lateral velocity) 
best ensures that only those lane departure systems affording robust 
performance achieve passing results during the Agency's testing. It is 
for this reason that the Agency does not plan to adopt a reduced test 
matrix with fewer lateral velocities, as several commenters suggested. 
NHTSA agrees with GM that conducting additional runs with slightly 
different parameters (i.e., incremented lateral velocity) for a given 
test scenario can be accomplished rather quickly. Furthermore, NHTSA 
expects that its attempt to harmonize to a large extent with Euro 
NCAP's LSS test protocol for its future lane keeping tests should, as 
Auto Innovators suggested, further reduce burden such that this 
concession is not necessary.
15. Number of Required Trials To Pass, Repeat Trials, and Pass Rate for 
LKA
    Similar to its request for other ADAS technologies proposed for 
adoption as part of this update to NCAP, the Agency sought feedback 
from commenters on an appropriate number of test trials to adopt for 
each LKA test condition, and an acceptable pass rate.
Summary of Comments
    Comments on these topics were varied, with some commenters 
suggesting that only one test trial for each test condition was 
appropriate, and others recommending up to seven trials per test 
condition.
    Those favoring one test trial per LKA test condition and lateral 
velocity included TRC, IDIADA, and HATCI. IDIADA suggested that current 
systems are very robust such that performance is repeatable. They also 
noted that system robustness can be evaluated two ways--performing the 
same test many times (as NHTSA currently does) or performing many tests 
one time. TRC and HATCI mentioned that if a system did not pass 
requirements at a given test speed (i.e., lateral velocity), 
performance could be verified with an additional test run (TRC) or runs 
(HATCI) at that speed. HATCI mentioned performing seven runs in such 
instances and proposed a pass rate of five out of seven. TRC also 
recommended that testing cease and not progress through higher lateral 
velocities if poor performance is observed for two of three test runs.
    Some commenters (GM, Rivian, FCA, Toyota, and ASC), preferred 
maintaining the number of trials and pass rate from NCAP's current LDW 
test. Currently, NCAP performs five trials for each of the LDW test 
conditions (defined by a combination of lane type and departure 
direction), and vehicles must pass three out of the five trials (60 
percent) for each test condition, and 20 of the 30 trials (66 percent) 
overall. Both Rivian and GM stated five trials would be sufficient to 
assure reliability of system performance, and a pass rate of three out 
of five would suffice to address any variances in testing conditions. 
In general, GM favored optimizing the number of test conditions rather 
than reducing the number of test runs since the former does more to 
reduce overall test burden and the latter leads to a diminished 
understanding of system performance variation. However, GM also noted 
that WIP SAE J3240 is proposing four tests per condition and a pass 
rate of 75 percent (i.e., three out of four).
    Other commenters, including Bosch, BMW, Tesla, and Auto Innovators, 
supported a pass rate of two out of three, with BMW specifying that the 
pass rate apply for each lateral velocity. The automaker stated that 
the Agency should accept one failed run since perfect system 
performance in the real world cannot be guaranteed. Tesla

[[Page 96070]]

suggested that the Agency harmonize test protocols with Euro NCAP, but 
in instances of failed runs, NHTSA should repeat the test at least two 
more times (i.e., three runs in total) to assess ``performance 
consistency.'' Auto Innovators said that although it supports the 
current pass rate (i.e., five out of seven), it would also support a 
reduced pass rate of two out of three to lessen test burden.
    Intel expressed no preference on either the number of runs 
conducted for each test condition or the pass rate adopted for LKA 
testing, but suggested that NHTSA try to minimize test burden when 
deciding what is appropriate. CAS stated that NHTSA use a binomial 
distribution to determine an appropriate reliability and confidence so 
that consumers may know how reliable a technology is. Advocates opined 
that the Agency should select the number of trials and pass/fail 
criteria to ensure a higher level of confidence in testing to assure 
consumers that the system will work as intended across a wide range of 
road and line conditions, not just those limited conditions assessed by 
NHTSA during testing.
Response to Comments and Agency Decisions
    For each LKA test condition, NHTSA will follow a testing approach 
similar to those it has adopted for the other ADAS technologies 
included in this notice. The Agency will increment the SV's lateral 
velocity towards the lane line in 0.1 m/s (0.3 ft./s) increments from 
the minimum lateral velocity to the maximum for each of the required 
tests (i.e., 0.2 m/s to 0.6 m/s (0.7 ft./s to 2.0 ft./s)), conducting 
one trial for each required lateral velocity. In the event the SV fails 
to provide an acceptable LKA system intervention or fails to issue an 
LDW warning that meets the requirements outlined for the Agency's 
tests, testing will cease for the test condition, the test scenario, 
and LKA testing overall. Vehicles must pass all required trial runs 
(i.e., one run per lateral velocity) for all test conditions to receive 
credit for the lane keeping tests. A vehicle that provides an 
acceptable LDW alert in all trials, but fails to produce an acceptable 
LKA intervention for a given run, will not separately receive credit 
for LDW and vice versa.
Number of Test Trials/Repeat Trials
    Like AEB and PAEB, several respondents recommended that the Agency 
perform multiple trials (e.g., two, three, four, five, seven, etc.) for 
each LKA test variant (i.e., for each lateral velocity assessed for 
each test condition), often with the number of recommended trials 
varying based on prior results. However, NHTSA has made the decision to 
run only one valid trial per LKA test variant. The Agency concludes 
this decision, which aligns with what it has adopted for AEB and PAEB 
testing, as well as for BSW and BSI, is appropriate for the LKA tests 
as well.
    The adopted testing approach will limit test burden while ensuring 
a greater number of real-world crashes are represented. As mentioned, 
the Agency will assess LDW alerts for multiple lateral velocities 
instead of one, as is required currently. NHTSA has also added a 
modified version of Euro NCAP's ELK Solid Line tests, which will 
include two additional lane marking types (i.e., dashed white and solid 
yellow) and double lane lines, to its LDW/LKA test matrix to assess 
secondary departures. While this results in (at most) 50 test trials 
overall for the Agency's LKA testing, this is less than the number of 
trials that will be required for the Agency's PAEB tests and far fewer 
than the number of trials that would be required if NHTSA were to adopt 
an approach that required five trials per test variant (as is currently 
specified for its LDW tests) for each of the 10 test conditions adopted 
for LKA. Adopting five trials per test variant, as some commenters 
suggested, would result in 250 total test trials for the Agency's LKA 
testing. This would be a significant burden to both vehicle 
manufacturers and NHTSA and would prohibit the Agency from 
communicating safety information quickly to consumers.
    NHTSA's decision to conduct one trial per test variant and 
discontinue testing upon the first instance of the system's inability 
to satisfy the associated performance requirements limits consumer 
confusion and better instills confidence and reliability in a vehicle's 
LDW and LKA systems. As the Agency has mentioned previously for other 
ADAS technologies, conducting repeat trials in the event the system 
fails to meet test procedural requirements--essentially, giving a 
system multiple opportunities to pass--may provide consumers with a 
false assurance of system robustness and repeatability. So, while BMW 
suggested that the Agency should accept a limited number of failures in 
system performance during testing because system performance cannot be 
guaranteed under all real-world conditions, NHTSA disagrees. An 
assessment approach that affords no tolerance for system error during 
controlled laboratory testing best assures that passing systems offer 
robust performance during real-world operation.
    Furthermore, while other respondents expressed that the Agency 
should perform multiple trials for each test variant to ensure system 
reliability, the Agency maintains, as it conveyed for other ADAS 
technologies prior, that it is appropriate to require one trial run per 
test variant instead of multiple runs to achieve this goal. This point 
was echoed by IDIADA in its comments. The test laboratory asserted that 
system robustness can be evaluated two ways--either the same test can 
be performed many times, or, as NHTSA intends, many tests can be 
performed one time. Since, as discussed earlier, NHTSA will increment 
the SV's lateral velocity by 0.1 m/s (0.3 ft./s) from the minimum 
lateral velocity established for each test condition to the maximum, 
the slight increase in lateral velocity from one trial to the next 
should effectively provide the same benefit of assuring reliability as 
multiple runs conducted at the same speed. Inconsistent systems may 
pass at one lateral velocity but will likely fail at another (higher) 
lateral velocity as the test stringency increases. Since a failure of 
any one run at any given lateral velocity for any one test condition 
will result in an overall test failure for the tested vehicle, NHTSA 
concludes its approach is sufficient to serve as an acceptable gauge of 
system robustness.
    The Agency's planned test method affords the most balanced approach 
to ensure system reliability across a wide range of real-world 
conditions with an acceptable degree of confidence without 
exponentially increasing test burden, sacrificing program integrity, or 
introducing delays in providing information to consumers.
Pass Rate
    As mentioned, NHTSA has decided to adopt a pass rate of 100 percent 
for NCAP's LKA testing. This decision aligns with the Agency's choice 
for the other ADAS technologies discussed herein. Both LDW and LKA 
systems must achieve passing results (i.e., issue a warning or 
intervention, respectively, to meet the associated performance 
requirements) for all adopted test conditions (i.e., 50 tests) to 
receive credit for lane keeping technology. By dictating a 100 percent 
pass rate, consumers will be able to quickly recognize which vehicles 
offer robust, repeatable system performance.
    The Agency has decided not to assign credit separately for LDW and 
LKA since the LDW and LKA requirements will be fundamentally linked 
such that an LDW alert will be a requirement for the LKA tests. 
Furthermore, like FCW,

[[Page 96071]]

which the Agency will similarly not provide separate credit, LDW is an 
existing warning technology in NCAP. NHTSA reasons that it is not 
appropriate to continue to assign separate credit to an existing 
warning system (i.e., LDW) once the complementary active safety system 
(i.e., LKA) is introduced. This decision does not pertain to BSW and 
BSI since both blind spot technologies are simultaneously being added 
to NCAP as part of this program update. Furthermore, unlike the test 
procedure requirements for FCW and AEB as well as LDW and LKA, which 
will share the same test scenarios, different test scenarios are being 
adopted for BSW and BSI technology.
    Test scenarios and conditions adopted for LDW/LKA testing are shown 
in Table 25.

                                Table 25--Lane Departure Warning (LDW)/Lane Keeping Assist (LKA) Adopted Test Conditions
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                                                                                 Passing criteria
                                                                                                              Lateral    -------------------------------
              Test scenario                          Line type                 Departure  direction        velocity (m/s    Maximum SV       LDW alert
                                                                                                             (ft./s))      excursion (m      issued (m
                                                                                                                              (ft.))          (ft.))
--------------------------------------------------------------------------------------------------------------------------------------------------------
Primary Departure........................  Solid White.................  Left...........................       0.2 (0.7)     -0.3 (-1.0)    0.75 to -0.3
(Single Straight Lane Line)..............                                                                      0.3 (1.0)                   (2.5 to -1.0)
                                                                                                               0.4 (1.3)
                                                                                                               0.5 (1.6)
                                                                                                               0.6 (2.0)
                                           Solid White.................  Right..........................       0.2 (0.7)
                                                                                                               0.3 (1.0)
                                                                                                               0.4 (1.3)
                                                                                                               0.5 (1.6)
                                                                                                               0.6 (2.0)
                                           Dashed Yellow...............  Left...........................       0.2 (0.7)
                                                                                                               0.3 (1.0)
                                                                                                               0.4 (1.3)
                                                                                                               0.5 (1.6)
                                                                                                               0.6 (2.0)
                                           Dashed Yellow...............  Right..........................       0.2 (0.7)
                                                                                                               0.3 (1.0)
                                                                                                               0.4 (1.3)
                                                                                                               0.5 (1.6)
                                                                                                               0.6 (2.0)
                                           Raised Pavement Markers.....  Left...........................       0.2 (0.7)
                                                                                                               0.3 (1.0)
                                                                                                               0.4 (1.3)
                                                                                                               0.5 (1.6)
                                                                                                               0.6 (2.0)
                                           Raised Pavement Markers.....  Right..........................       0.2 (0.7)
                                                                                                               0.3 (1.0)
                                                                                                               0.4 (1.3)
                                                                                                               0.5 (1.6)
                                                                                                               0.6 (2.0)
Secondary Departure......................  Solid Yellow (L)/Dashed       Left...........................       0.2 (0.7)     -0.3 (-1.0)    0.75 to -0.3
(Dual Straight Lane Line)................   White (R).                                                         0.3 (1.0)                   (2.5 to -1.0)
                                                                                                               0.4 (1.3)
                                                                                                               0.5 (1.6)
                                                                                                               0.6 (2.0)
                                           Solid Yellow (L)/Dashed       Right..........................       0.2 (0.7)
                                            White (R).                                                         0.3 (1.0)
                                                                                                               0.4 (1.3)
                                                                                                               0.5 (1.6)
                                                                                                               0.6 (2.0)
                                           Dashed White (L)/Solid White  Left...........................       0.2 (0.7)
                                            (R).                                                               0.3 (1.0)
                                                                                                               0.4 (1.3)
                                                                                                               0.5 (1.6)
                                                                                                               0.6 (2.0)
                                           Dashed White (L)/Solid White  Right..........................       0.2 (0.7)
                                            (R).                                                               0.3 (1.0)
                                                                                                               0.4 (1.3)
                                                                                                               0.5 (1.6)
                                                                                                               0.6 (2.0)
--------------------------------------------------------------------------------------------------------------------------------------------------------

16. Test Procedure Changes and Refinements
    The Agency also asked commenters if there are any aspects of NCAP's 
current LDW or proposed LKA test procedure that need further refinement 
or clarification.
Summary of Comments
    Comments on this topic were varied and ranged from test procedure 
clarifications to future considerations.

[[Page 96072]]

Comments are grouped into general topics below.
Lane Line, Environmental, and Traffic Conditions
    TRC, GM, Toyota, and Auto Innovators requested that the Agency 
clarify the lane line condition that is acceptable for testing to 
improve repeatability and reproducibility. The latter three commenters 
asserted that lane lines must be ``of high quality and free from 
irregularities'' to not affect detection and thus, system performance. 
Accordingly, they recommended that there be no coal tar, tire marks, 
shadows/reflections, or faded markings, while TRC additionally 
requested clarification regarding brightness specifications. In 
contrast, AASHTO suggested NHTSA should perform LDW and LKA testing 
using roadway conditions prevalent in the real world, including faded 
and undetectable lane markings, since lane markings undergo wear and 
tear and vary with weather conditions. CAS mentioned the U.S. typically 
uses double lines to separate vehicle travel lanes from bicycle lanes, 
whereas Europe often uses physical barriers to create lane separation. 
Given the rise in fatalities for cyclists, CAS asserted that it was 
necessary to assess U.S. roadway conditions. CAS also proposed that the 
Agency adopt tests to assess general system functionality under certain 
environmental conditions (e.g., rain, ice, fog, low sun angles, roadway 
conditions, line of sight, etc.), traffic conditions (e.g., congestion, 
density), or operating conditions (e.g., speed) and ensure that 
vehicles inform drivers via a warning when the system is not working.
Test Procedure Changes
    Regarding test procedure changes, GM and Auto Innovators proposed 
that NHTSA harmonize conceptually with Euro NCAP by specifying use of a 
particular robot, e.g., the ABD SR15 steering robot, to initiate drift 
during LKA testing. Both organizations also asked that NHTSA devise a 
procedure to ensure that robot friction and inertia do not affect 
system performance, as well as consider procedural clarifications for 
steering friction and electric power steering tuning.
    Rivian asked that the Agency add ``improved illustrations'' and 
``diagrams detailing what passing each test looks like'' to the LKA 
test procedure so that manufacturers may better understand each test 
scenario.
    Finally, Auto Innovators recommended that NHTSA adopt the 
nomenclature in SAE J3063 and the Clearing the Confusion: Recommended 
Common Naming for Advanced Driver Assistance Technologies document.
Additional Scenarios
    Some commenters suggested test procedure additions. Massachusetts 
Vision Zero Coalition and Vision Zero Network, among others, suggested 
that the Agency should perform an assessment of LKA systems to ensure 
they respond appropriately to passing cyclists (i.e., allow a safe 
distance--minimum of three feet--between the vehicle and cyclist when 
passing). Similarly, the League and NACTO requested that the Agency 
conduct research on LDW and LKA systems to document their interactions 
with cyclists and pedestrians (NACTO), because anecdotal reports 
suggest that systems are providing unwanted corrections when drivers 
attempt to cross a double-yellow center line into an opposing traffic 
lane to pass a cyclist safely. Like other commenters, NACTO stated that 
vehicles' LKA systems should provide cyclists with at least three feet 
of space while passing, as this is required by law in 36 states and the 
District of Columbia.
    ASC, Aptiv, and an anonymous commenter recommended that the Agency 
consider how to change the current LDW/LKA test protocol to evaluate 
lane centering systems, a system the groups asserted NHTSA should 
encourage. These respondents stated that NHTSA could likely use the 
current LDW/LKA test protocol for testing of lane centering systems, 
but requirements for such systems should be more stringent. The 
commenters also suggested that it would be ``highly appropriate'' to 
include enhanced curved road testing as part of a lane centering test 
procedure. ITS reasoned that NHTSA should include lane centering assist 
alongside the other two lane keeping technologies in NCAP because the 
Agency noted it, too, can address the same pre-crash scenarios. The 
company requested details on why this technology was excluded.
    Advocates recommended that the Agency develop tests to limit false 
positives for LDW based on the most frequent causes of dissatisfaction 
and non-use., based on the reported driver satisfaction issues with LDW 
and the frequency with which such systems are turned off as a result. 
In contrast, Aptiv and ASC did not support the addition of a false 
positive test for LKA systems. One anonymous public commenter stated 
that NHTSA should consider evaluating systems for how they react after 
a period of driver inactivity, suggesting that the Agency should have 
requirements for how long the system should operate without driver 
action and specify what the system should do in such instances (e.g., 
bring the vehicle safely to stop).
    While Auto Innovators generally supported harmonization with Euro 
NCAP, the group did not support adoption of several of the consumer 
information program's LSS scenarios for U.S. NCAP's LDW/LKA tests. In 
addition to the ELK Overtaking vehicle scenario already discussed 
previously in the Removal or Integration of LDW section, the 
organization recommended that NHTSA not include the ELK Oncoming 
vehicle scenario as well. The group remarked that it is similar in 
intent to NHTSA's Oncoming Traffic Safety Assist (OTSA) test procedure, 
which was included in NCAP's roadmap.
Response to Comments and Agency Decisions
Lane Line, Environmental, and Traffic Conditions
    A wide variety of road conditions exist across the U.S. 
Nonetheless, one of the Agency's main objectives is to evaluate each 
vehicle model against the same protocol. To maintain a reasonable test 
burden, testing with multiple lane line and all pavement surface 
conditions that a vehicle may encounter is not possible. This is also a 
reason that NHTSA is unable to test general system functionality under 
multiple atmospheric conditions and traffic conditions.
    That being said, it is necessary to clearly specify pavement 
condition and marking qualities to ensure vehicle models are undergoing 
the same procedure. The Agency will maintain the road test surface and 
lane line markings specifications currently included in NCAP's LKA 
draft test procedures. Specifically, the road test surface shall be a 
dry, uniform, solid-paved high-mu surface having no debris, 
irregularities, or undulations, such as loose pavement, large cracks, 
or dips. The road test surface shall produce a peak friction 
coefficient (PFC) of 1.02  0.05 when measured using ASTM 
F2493 standard reference test tire when tested in accordance with ASTM 
Method E 1337-19 at a speed of 64.4 kph (40 mph), without water 
delivery.\438\ Surface friction is a critical factor in testing LKA 
systems as vehicles are dynamically assessed for various conditions, 
including multiple lateral velocities and turns. Vehicles

[[Page 96073]]

also use steering and/or braking maneuvers for the LKA intervention 
during testing. Thus, the presence of moisture will significantly 
change the measured performance of a vehicle's ability to turn. A dry 
surface is more consistent and provides for greater test repeatability. 
Lane line markings shall have high contrast, meet U.S. DOT 
specifications, as required by the MUTCD, and be considered in very 
good condition. Lane marker color and reflectivity shall meet all 
applicable standards from the International Commission of Illumination 
(CIE) for color and the American Society for Testing and Materials 
(ASTM) on lane marker reflectance.
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    \438\ ASTM E1337-19, Standard Test Method for Determining 
Longitudinal Peak Braking Coefficient (PBC) of Paved Surfaces Using 
Standard Reference Test Tire.
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    With respect to environmental conditions, the Agency's lane keeping 
technology tests will be performed when the ambient temperature is any 
temperature between 0[deg] C (32[deg] F) and 40[deg] C (104[deg] F) and 
the maximum wind speed is no greater than 10 m/s (22 mph). While the 
Agency reasons that lane keeping systems can operate acceptably at 
lower temperatures, the limiting factor is braking performance during 
LKA interventions. NHTSA has selected an ambient temperature range that 
matches the range specified in NHTSA's safety standard for brake system 
performance.\439\ Excessive wind during testing could affect the 
ability of the SV to maintain consistent speed and/or lateral position.
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    \439\ FMVSS No. 135, ``Light vehicle brake systems,'' https://www.ecfr.gov/current/title-49/subtitle-B/chapter-V/part-571/subpart-B/section-571.135.
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    Tests will be conducted during daylight hours with an ambient 
illumination on the test surface that is not less than 2,000 lux, as 
this approximates the minimum light level on a typical roadway on an 
overcast day. In addition, to better ensure test repeatability, testing 
may not be performed while driving toward or away from the sun such 
that the horizontal angle between the sun and a vertical plane 
containing the centerline of the subject vehicle is less than 25 
degrees and the solar elevation angle is less than 15 degrees. The 
intensity of low-angle sunlight can create sensor anomalies that may 
lead to unrepeatable test results. Visibility (i.e., a clear field of 
view) must be 5 km (3.0 mi) or greater. Testing will not be run during 
periods of precipitation (i.e., rain, snow, or hail) or when visibility 
is affected by fog, smoke, ash, or other particulate. NHTSA reasons 
that the presence of precipitation could influence the outcome of lane 
keeping tests because wet, icy, or snow-covered pavement has lower 
friction. Conducting a test under those conditions also poses risks to 
lab personnel. This choice is also supported by crash data from 2011 to 
2015 which shows that 91 percent of fatal and 87 percent of injurious 
road departure crashes occurred in clear weather and 87 percent of 
fatal and 81 percent of injurious road departure crashes occurred on 
dry roadway surfaces, on average, annually.\440\ Additionally, when 
considering opposite-direction crashes, 88 percent of fatal and 85 
percent of injurious crashes occurred during clear conditions, and 83 
percent of fatal and 76 percent of injurious crashes occurred on dry 
roadway surfaces on average, annually.\441\
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    \440\ For road departure crashes, weather conditions were 
unknown or not reported in 1 percent of fatal crashes. Roadway 
surface conditions were unknown or not reported in 1 percent of 
fatal road departure crashes and 2 percent of road departure crashes 
with injuries.
    \441\ For opposite direction crashes, weather conditions were 
unknown or not reported in 1 percent of fatal crashes.
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    As stated in the March 2022 notice, LDW telltales are often present 
when the activation threshold speed, lane markings, and environmental 
conditions meet system requirements. These telltales disappear when the 
system is inoperable due to inadequate conditions or those which 
introduce too much uncertainty for the vehicle's systems to function. 
Given the lack of a telltale indicates to the driver a change in system 
status, NHTSA chose not to propose a requirement that the vehicle issue 
an alert if the lane keeping system is not functioning. This decision 
will be upheld for this NCAP update.
Test Procedure Changes
    The Agency will use the AB Dynamics SR15 steering robot for its LKA 
tests, as GM and Auto Innovators requested. Due to its inherent low 
inertia, low drag (i.e., friction) design, NHTSA concludes it is 
unnecessary to devise a procedure to ensure that steering robot 
friction and inertia do not affect system performance. It can also be 
installed on the steering wheel without removing the airbag.
    NHTSA has reviewed its LDW and LKA test procedures for the release 
of this final notice and has added descriptive language and 
illustrations to improve clarity of the procedures, as Rivian has 
requested.
    The Agency has also adopted the nomenclature for lane keeping 
systems in SAE J3063 and the Clearing the Confusion: Recommended Common 
Naming for Advanced Driver Assistance Technologies document, as Auto 
Innovators requested. As reflected throughout this notice and in the 
accompanying test procedure, the Agency will refer to lane keeping 
systems as Lane Keeping Assistance (LKA) systems.
Additional Scenarios
    While NHTSA is not actively conducting research or developing test 
procedures to assess the performance of LDW and/or LKA systems around 
cyclists and pedestrians, in light of the comments received, it will 
consider doing so in the future.
    NHTSA recognizes that SAE has recently finalized a performance-
based test procedure to assess LCA systems; however, at this time, the 
Agency has not had a chance to evaluate this protocol to determine its 
acceptability for adoption in NCAP.\442\ Even minor changes to its 
current LDW/LKA test protocol to make requirements more stringent, as 
ASC and Aptiv suggested, would require evaluation. Accordingly, LCA 
performance will not be assessed as part of this NCAP update. That 
being said, as noted earlier when discussing secondary departures after 
an initial LKA intervention, NHTSA expects that vehicles will continue 
to undergo lane centering design improvements even without a prescribed 
test. The Agency will reconsider assessing the performance of LCA 
systems in NCAP once it has thoroughly evaluated the SAE test 
procedure.
---------------------------------------------------------------------------

    \442\ SAE J3240, Passenger Vehicle Lane Departure Warning, Lane 
Keeping Assistance, and Lane Centering Assistance Systems Test 
Procedure, published December 20, 2023, includes provisions for an 
LCA assessment.
---------------------------------------------------------------------------

    Regarding false positive testing for lane keeping technologies, 
NHTSA maintains its previous stance that a lane keeping technology 
false positive test is not appropriate at this time. Concerns with 
repeatability and reproducibility exist currently with respect to 
defining the appropriate delineation between a driver who is actively 
steering and not utilizing the turn signal, such that the system should 
be suppressed, and one who is not, such that the intervention would be 
necessary. This delineation must be assured to adequately address 
consumer acceptance issues. NHTSA plans to conduct research to assess 
such situations, as well as others where LKA interventions should be 
suppressed, such as when ESC, FCW, and/or AEB is in operation, or when 
a VRU is residing at a 25 percent offset in the SV travel lane. The 
Agency also notes it is further investigating human factors involved 
during intended and unintended driver maneuvers for future 
applications. Nuisance alerts often occur because the driver's intent 
to maneuver in a

[[Page 96074]]

particular direction does not align with the vehicle's movement due to 
poor environmental/road conditions and/or vehicle hardware or software 
shortfalls for a particular situation. Currently, the Agency defines 
driver intent by the vehicle's lateral velocity; low lateral velocity 
is meant to simulate unintended drift without the use of a turn signal. 
It is possible that other information gathered by the vehicle (i.e., 
torque on the steering wheel, steering rate, driver gaze, etc.) can 
play a role in determining a driver's intent to maneuver, thus allowing 
the vehicle to suppress unnecessary warnings and activations. Data 
gathered may also help inform next steps to address concerns regarding 
driver inactivity or distraction, which may result in unintended 
drifting. NHTSA notes this human factors research is ongoing, and the 
Agency continues to monitor consumer complaint data related to false 
positive activations of LDW and LKA systems. NHTSA will consider 
adopting additional LDW/LKA tests in the future to address relevant 
safety needs if such tests are found to be repeatable and reproducible 
during the Agency's research.
    At this time, as Auto Innovators requested, NHTSA is not adopting 
Euro NCAP's ELK Overtaking vehicle or ELK Oncoming vehicle scenarios 
for NCAP's LDW/LKA assessments. However, as indicated previously, the 
Overtaking vehicle scenarios is similar to two of the test scenarios 
adopted for the NCAP's BSI assessments--the SV Lane Change with 
Constant Headway scenario and SV Lane Change with Closing Headway 
scenario.

VIII. Self-Reported Data

    Currently, through the Agency's approved information 
collection,\443\ vehicle manufacturers report internal physical test 
data that demonstrates whether the recommended ADAS technologies 
installed on their vehicle models pass NHTSA's system performance test 
requirements. NHTSA uses this data, in conjunction with random 
verification testing, to determine whether each vehicle model's 
performance meets NCAP's requirements. This process, in place since 
model year 2011, has been critical to the successful administration of 
the program. However, as the Agency noted in its March 2022 RFC, there 
are challenges associated with this process. NHTSA has identified 
inconsistencies in vehicle manufacturers' self-reported data 
submissions, many of which may stem from unfamiliarity with NCAP's test 
procedures. To address this issue, NHTSA stated one approach would be 
to require all vehicle manufacturers to provide data from independent 
test facilities that meet criteria demonstrating competence in NCAP 
testing protocols. NHTSA concludes that this step would help the Agency 
maintain credibility and retain public trust in its program.
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    \443\ NHTSA has a current information collection under the 
Paperwork Reduction Act (OMB Control Number: 2127-0629) to obtain 
vehicle information for the general public in support of NCAP. The 
information collection requests responses from major motor vehicle 
manufacturers about the crashworthiness, crash avoidance, and other 
capabilities of their vehicle models. The collection is voluntary 
and conducted annually. The information is primarily used to provide 
information to consumers. It is used to disseminate safety 
information on http://www.nhtsa.gov/ratings and to address consumer 
inquiries as well as for internal agency analyses.
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A. NHTSA's Proposals, Summary of Comments, Response to Comments, and 
Agency Decisions

1. Self-Reported Data From Non-NHTSA Contracted Laboratories
    In its March 2022 RFC notice, NHTSA proposed to only accept self-
reported ADAS performance data from designated NHTSA-contracted 
laboratories.
Summary of Comments
    Commenters were divided on whether the Agency should only accept 
self-reported test data from NHTSA's contracted test laboratories. TRC, 
Auto Innovators, Honda, GM, Mitsubishi, Toyota, FCA, Tesla, and Hyundai 
stated that the Agency should continue to accept self-reported test 
data from non-NHTSA contracted test laboratories, as restricting 
acceptance of data to NHTSA-contracted laboratories may increase burden 
and contribute to delays in the dispensing of information to the 
public. Honda, among others, cautioned that if the Agency limits 
testing to only NHTSA's contracted test laboratories, there may not be 
sufficient capacity available to complete all required testing, 
especially considering the proposed additions to the ADAS testing 
program. Vehicle models would then not receive credit for having a 
NHTSA-approved ADAS technology despite being otherwise eligible. FCA 
noted that self-reported data is accepted for FMVSS compliance and 
should therefore be acceptable for NCAP as well. Honda further 
requested clarification regarding NHTSA's statement in its March 2022 
RFC that NHTSA will refuse data when it is not provided from a test 
facility that is designated as a NHTSA-contracted test lab or when 
tests are not conducted in accordance with NCAP's protocols, noting 
that the Agency's use of ``or'' was unclear.
    TRC, a test laboratory, offered that the criteria most relevant to 
the successful conducting of ADAS testing are quality process and 
management accreditation, facility and lane marking conditions, 
equipment condition, calibration and traceability, independence, and a 
positive history of performing testing. Mitsubishi requested that test 
laboratories be made available in other world regions, including Japan.
    Auto Innovators acknowledged NHTSA's desire to maintain program 
credibility and proposed that this could still be done while allowing 
manufacturers to conduct testing at an in-house or third-party 
facility. The group supported the Agency's ability to request test 
documentation and to review any relevant data related to the vehicle or 
test facility on a case-by-case basis. Tesla also suggested that NHTSA 
could request a dossier containing evidence of a valid ADAS test prior 
to granting credit, similar to Euro NCAP's process.
    On the other hand, CAS, Bosch, Advocates, and a public commenter 
supported accepting self-reported test data only from NHTSA-contracted 
test laboratories. CAS suggested that NHTSA publish standards with 
which laboratories could comply and become a NHTSA-certified lab as 
well as standards for third-party organizations to audit and certify 
other laboratories. The public commenter opined that the Agency might 
consider accepting data from laboratories contracted for UN ECE 
testing. Bosch strongly opposed self-reported data altogether and 
proposed that tests should be conducted and/or contracted by an 
authority to ensure the repeatability and reproducibility of results. 
The company referred to Euro NCAP's testing process, in which vehicle 
manufacturers, test laboratories, or a third party pays for a vehicle 
test, and one of Euro NCAP's eight test laboratories must perform the 
testing.
Response to Comments and Agency Decisions
    Regarding Honda's request for clarification on its proposal, 
NHTSA's intent was to not accept manufacturers' self-reported data that 
is either (1) derived from tests that were not conducted in accordance 
with NCAP's testing protocols, or (2) generated by test laboratories 
that are not contracted by the Agency to perform the tests in question, 
regardless of whether test protocols were followed. The Agency's 
proposal differed from the current submission process, which allows

[[Page 96075]]

manufacturers to provide test data from any test laboratory if the test 
is deemed valid by the manufacturer.
    Maintaining public trust is critical and has been NHTSA's long-
standing goal for NCAP. However, NHTSA acknowledges that the concerns 
expressed by Honda and others regarding test laboratory capacity is 
credible. Delays in test scheduling will ultimately translate to delays 
in providing updated information to the American public. Due to the 
limited number of NHTSA-contracted test laboratories currently 
available, it is not currently practicable to require manufacturers to 
perform ADAS testing at NHTSA-contracted laboratories in order to gain 
NCAP ADAS credit.
    As such, the Agency has determined that for data gathered in 
response to this NCAP update, vehicle manufacturers may utilize an in-
house or third-party facility, either in the U.S. or globally, provided 
that the test is conducted (1) in accordance with NCAP's test 
procedures and (2) using U.S. production-level vehicles identical to 
those that could be purchased by a consumer at dealers' lots in the 
U.S. at any particular time during a given model year. However, it 
should be noted that this decision is subject to change in the future. 
For example, when NHTSA completes a rulemaking to update the Monroney 
label, the Agency may require the use of specific laboratories to 
generate ratings data, a testing method already used for NCAP's 
optional testing program. Under this provision, vehicle manufacturers 
fund desired testing through specified laboratories; however, test 
setup, test conduct, and data quality control must adhere to NHTSA's 
protocols.\444\ In addition, NHTSA wants to be clear that vehicles 
failing to provide passing performance during the Agency's assessments 
will not receive credit for the related technology, regardless of 
whether passing results were provided by the vehicle manufacturer in 
response to the NCAP's annual data information request.
---------------------------------------------------------------------------

    \444\ 52 FR 31691.
---------------------------------------------------------------------------

2. Other Means To Address Programmatic Challenges With Self-Reported 
Data
    The Agency requested feedback from the public regarding new ways to 
alleviate some of the programmatic challenges it has encountered with 
NCAP ADAS testing.
Summary of Comments
    GM and ASC suggested NHTSA should accept virtual forms of testing 
data, including computer simulations, software-in-the-loop, and 
hardware-in-the-loop methods. GM noted that producing data in this way 
would be more resource efficient. ASC recommended allowing a combined 
submission including real and virtual tests, particularly upon 
implementation.
    Auto Innovators and HATCI suggested the Agency engage with vehicle 
manufacturers to provide clarity regarding test procedures. In 
particular, HATCI proposed that NHTSA conduct test procedure 
``workshops'' to ensure that vehicle manufacturers and test 
laboratories have a common understanding of test conduct practices. 
Auto Innovators noted that updates to test procedures could be made to 
ensure more repeatable and reproducible results. Along those lines, GM 
supported a thorough test procedure development process involving the 
development of confidence intervals and adjustment to procedures after 
enough NHTSA-sponsored and internal tests are conducted.
    Consumer Reports supported efforts to continuously review the NHTSA 
complaints database for ADAS systems as well as defect investigations 
to identify situations where systems may be creating ``a perceived or 
real risk'' of increasing crashes rather than mitigating them. The 
group also proposed reviewing data for consumer acceptance issues, such 
as ADAS false activations in the real world.
Response to Comments and Agency Decisions
    The Agency will accept only self-reported data from physical 
testing at this time. NHTSA acknowledges that manufacturers must gather 
a significant amount of data to receive credit for any of the ADAS 
technologies recommended in NCAP. However, at this time, there is not 
sufficient evidence that virtual or computer-generated data would 
sufficiently demonstrate that vehicle models meet NCAP's ADAS 
performance requirements.
    As mentioned throughout this notice, NHTSA plans to closely monitor 
real-world data for problematic activations, unintended consequences, 
and consumer acceptance concerns. As ADAS technologies become more 
prevalent in the fleet and more complex, it is critical that the Agency 
keeps abreast of the changing crash landscape. The Agency also plans to 
continue its research efforts to make ongoing improvements to the 
program, as discussed in the following NCAP Roadmap section.

IX. NCAP Roadmap

    In accordance with section 24213(c) of the BIL, the March 2022 RFC 
notice proposed a 10-year roadmap setting forth NHTSA's plans to 
upgrade NCAP with mid-term plans spanning 2024 through 2028 and long-
term plans spanning 2024 through 2033. NHTSA has long-established 
criteria for evaluating safety technologies for inclusion in NCAP. 
Potential program updates must meet the following four prerequisites: 
(1) the update to the program addresses a safety need; (2) there are 
system designs that can mitigate the safety problem, (3) existing or 
new system designs have the potential to improve safety, and (4) a 
performance-based objective test procedure exists that can assess 
system performance.
    NHTSA uses the notice and comment process to seek public input on 
updates to NCAP and ensure the reasonableness of the time periods for 
NCAP changes, and the Agency expects this practice to continue. As part 
of the Agency's development of next steps for NCAP, NHTSA regularly 
evaluates other rating systems from vehicle safety consumer information 
programs within the United States and abroad, including whether there 
are safety benefits from consistency with those other rating systems.
    In the mid-term portion of the roadmap, NHTSA has included only 
those technologies that are practicable and for which objective tests, 
evaluation criteria, and other consumer data exist. The mid-term 
potential program updates proposed in the 2022 NCAP RFC included the 
following:
     Adding four ADAS technologies (LKA, BSW, BSI, and PAEB).
     Updating the performance evaluation of current recommended 
ADAS technologies (FCW, LDW, DBS, and CIB).
     Including evaluation of advanced lighting technologies and 
other ADAS technologies.
     Creating a new crash avoidance rating system.
     Updating the Monroney label to include crash avoidance 
rating information.
     Adding a crashworthiness pedestrian protection testing 
program.
     Adding the THOR-50M in NCAP's full frontal impact crash 
tests and the WorldSID-50M in NCAP's side impact barrier and side 
impact pole test.
     Considering a new frontal oblique crash test with the 
advanced THOR-50M.
    The long-term initiatives discussed in the March 2022 NCAP RFC 
notice

[[Page 96076]]

include a variety of new technologies with safety potential that are 
not sufficiently mature, and thus require additional agency research 
and review. These include: intersection safety assist (intersection 
AEB); opposing traffic safety assist; and more advanced automatic 
emergency braking that accounts for vehicles turning right or left at 
intersections across the path of pedestrians, as well as bicyclists, 
motorcyclists, and other VRUs in applicable crash scenarios. NHTSA also 
stated its intent to explore opportunities to encourage the development 
and deployment of emerging technologies for safe driving choices such 
as driver monitoring systems for reducing distraction and drowsy 
driving, intelligent speed assist, alcohol detection systems, seat belt 
interlocks, and rear seat child reminder assist.
    The March 2022 NCAP RFC notice explained that while the Agency can 
reasonably anticipate when the start of actions may occur in the mid-
term portion of the roadmap, many technologies in the long-term portion 
of the roadmap require additional research, test procedure development, 
and product development and maturity, among other factors. These 
factors prevent the Agency from providing more details on the 
anticipated start of action at this time. For the mid-term initiatives, 
the Agency stated that the completion of action and subsequent 
implementation dates are highly dependent upon the notice and comment 
process, among other factors. Specifically, the Agency stated that 
completion dates depend on the number and depth of the comments 
received in response to an RFC notice, along with any technical 
research necessary to resolve any challenging issues or potential 
policy considerations raised in the comments. Therefore, the March 2022 
NCAP RFC notice explained that the Agency cannot reasonably anticipate 
those timelines in advance.
    NHTSA requested comment on (1) safety opportunities or technologies 
in development that could be included in future roadmaps, (2) 
opportunities to benefit from collaboration or harmonization with other 
consumer vehicle safety information programs, and (3) other issues to 
assist with long-term planning.
Summary of Comments
    NHTSA received numerous comments on the proposed roadmap. Many 
commenters expressed general support for the proposed NCAP roadmap, 
with industry stakeholders noting that a roadmap with near, mid, and 
long-term strategies for updating NCAP incentivizes manufacturers to 
prioritize and accelerate the most relevant and effective safety 
technologies. However, many commenters, including Advocates for Highway 
and Auto Safety, the Consumer Federation of America, and Auto 
Innovators, stated that the proposed NCAP roadmap lacks sufficient 
specificity on future timelines, dates, and required actions. Industry 
stakeholders commented that the roadmap did not provide stakeholders 
with enough information to plan for the future. Stakeholders requested 
the roadmap include proposed and ongoing research and contain target 
dates for key milestones, decision points, and implementation of new 
program items to allow automakers to proactively plan and develop long-
term design strategies and technology integration. Commenters also 
requested that the NCAP roadmap timetables align with the three-to-
five-year duration associated with vehicle development.
    Several industry stakeholders (Honda, Toyota, BMW, Mercedes-Benz, 
GM and others) requested NHTSA harmonize the NCAP roadmap with other 
global programs, such as Euro NCAP, with appropriate objective test 
procedures and evaluations tailored to the U.S. market. Industry 
stakeholders stated that test procedures to evaluate new technologies 
should be objective, measurable, repeatable, and harmonized with other 
global NCAP test procedures where possible. Commenters noted that 
harmonizing the NCAP roadmap with global NCAPs will introduce safety 
technologies to U.S. consumers more quickly at reduced cost to 
consumers and manufacturers.
    Commenters encouraged NHTSA to establish regularly scheduled 
opportunities for stakeholder engagement and collaboration to develop 
the NCAP roadmap. Auto Innovators suggested establishing a 
representative advisory panel with annual discussions between NHTSA and 
stakeholders to help prioritize initiatives in the NCAP roadmap and 
establish timelines for the roadmap. Commenters also suggested updating 
the NCAP roadmap every three to five years depending on the current 
field data, available countermeasures, and effectiveness and safety 
implications of the available countermeasures.
    Auto Innovators and its members requested that NHTSA align NCAP 
initiatives with relevant ongoing regulatory actions. Industry 
stakeholders recommended ensuring consistency between NCAP and planned 
FMVSS where possible. Specifically, they requested that, similar to how 
the existing NCAP is structured for crashworthiness, FMVSS should set 
the baseline standard for vehicle performance, with NCAP requirements 
evaluating safety at a level either equal to, or above, the baseline. 
Safety advocates stated that vehicle safety standards that save lives 
outside the vehicle should not be left to consumer choice. For example, 
commenters stated that new NCAP items, such as better headlamps, 
redesigned hoods and bumpers, and direct visibility should be included 
in FMVSS.
    Commenters supported NHTSA's four prerequisites for inclusion of 
items into NCAP. However, industry stakeholders also requested that the 
roadmap include items for removal from NCAP for various reasons such as 
a parallel regulation already addressing the same target population.
    Industry stakeholders expressed concern that certain technologies 
such as alcohol ignition and seat belt interlocks may not be 
appropriate to include in or show effectiveness through NCAP. The 
stakeholders further explained that certain consumers may not 
voluntarily seek this type of technology in a vehicle purchase, and it 
may be difficult to convince the average consumer who refrains from 
driving under the influence or driving unrestrained that these 
technologies directly benefit them. In contrast, several safety 
advocates and organizations encouraged NHTSA to include testing in NCAP 
to mitigate the risk of alcohol-impaired driving, and limit distracted 
driving caused by infotainment systems and other sources.
    Commenters requested that NCAP updates include the latest safety 
technologies, including: rear cross-traffic warning and rear automatic 
braking, intersection safety assist, intelligent speed assist, driver 
monitoring systems (DMS), alcohol detection systems, and human-machine 
interaction. Several commenters suggested including rear seat child 
passenger detection and alert systems, along with bicyclist and 
motorcyclist crash avoidance and crash protection systems, similar to 
that in Euro NCAP. Several commenters also expressed concerns about 
vehicles with higher hoods and reduced direct visibility of pedestrians 
in the vicinity of these vehicles for the driver, requesting an 
evaluation of driver direct visibility in NCAP.
    Safety advocates and industry stakeholders requested including 
advanced lighting technologies, such as automatic high beam and high 
beam assist systems, in NCAP. Several commenters also requested 
enhanced testing scenarios in future NCAP

[[Page 96077]]

updates for all types of crash avoidance technologies to reflect less-
than-ideal conditions like low light, glare, and fog.
    Several commenters requested expanding the range of test dummies in 
crash tests to include dummies representing female occupants and older 
adults in driver and passenger seating positions. Additionally, 
commenters suggested that vehicle safety technology testing consider 
such factors as: micro-mobility, wheelchair users, bicyclists, and 
diverse human variations including size, shape, and skin color. 
Commenters also requested the use of advanced crash test dummies, 
(e.g., THOR-50M and WorldSID-50M), and the use of additional crash test 
conditions such as frontal oblique impacts and rear seat occupant 
protection.
    Several commenters requested the inclusion of vehicle communication 
systems (vehicle-to-vehicle and vehicle-to-everything technologies), 
while other commenters expressed cybersecurity and privacy concerns 
with such systems. Some commenters focused on post-crash safety and 
requested hazard lighting for disabled vehicles and automatic crash 
notification.
Response to Comments and Agency Decisions
    NHTSA has developed a final roadmap for updating NCAP in multiple 
phases for the period 2024 through 2033. The mid-term initiatives in 
the roadmap span the period 2024-2028 and the long-term items span the 
period 2024-2033. The NCAP roadmap in this decision notice includes 
four phases for each NCAP initiative, along with a completion milestone 
for each phase. The four phases are: (1) Research phase if applicable, 
(2) Request for comment (RFC) phase, (3) Final decision phase, and (4) 
Implementation phase.
    The Research phase may include field data analysis, test procedure 
and performance criteria development, and evaluation of vehicle 
technologies and designs. The Research phase may also include 
rulemaking to federalize tools used in the test procedures, such as new 
crash test dummies. The RFC phase includes the development of the 
proposal and publication of the RFC notice. The Final decision phase 
includes review of comments received, responding to the comments, and 
the publication of the final decision notice. The final test procedures 
and evaluation criteria will be provided in the final decision notice.
    Depending on the comments received, there could be additional 
research necessary between the RFC phase and Final decision phase. 
There could also be overlap between the Research phase with the RFC and 
Final decision phases to conduct supplementary research and draft and 
publish research reports supporting the NCAP notice. The Implementation 
phase generally begins one to two calendar years after the publication 
of the Final decision notice.
    While timing details are provided in the roadmap, NHTSA notes that 
some of the milestone dates may need to be changed in the future, as 
the completion of action and subsequent implementation dates are highly 
dependent upon the notice and comment process. NHTSA plans to update 
the NCAP roadmap approximately every four years, with timelines updated 
accordingly.
    NHTSA asserts that the notice and comment process, which seeks 
input from the public on updates to NCAP, works well and effectively. 
Thus, the Agency intends to continue to use this method to solicit 
input from the public on updates to NCAP. The Agency may also consider 
a stakeholder meeting on updating NCAP before an update to the roadmap 
is released.
    NHTSA will continue to monitor vehicle technologies and field data 
to select appropriate technologies and vehicle features to address 
safety needs. As requested by commenters, NHTSA will consider 
appropriate areas for harmonizing with other global programs such as 
Euro NCAP. In evaluating whether harmonization is appropriate, the 
Agency will assess existing procedures for updates to improve 
objectivity and ensure test procedures are representative of real-world 
crash conditions in the U.S. The Agency will also ensure any proposed 
tests can be used on U.S. vehicles to assess safety performance, and 
that the tests will evaluate technologies and vehicle designs 
addressing a U.S. safety need.
    This roadmap outlines NHTSA's plans to update NCAP in the following 
three safety programs: crashworthiness, crash avoidance, and VRU 
safety. The NCAP rating system will consider systems that could include 
any of the following combinations: (1) distinct ratings for each of the 
safety programs; (2) a safety rating that combines the three distinct 
ratings; (3) other options suggested by commenters and consumers. 
Future updates to the roadmap could include additional safety programs, 
evaluation of new technologies and vehicle design features, and 
enhanced evaluation of vehicle technologies and designs currently in 
NCAP. As described in its March 2024 response to GAO 
recommendations,\445\ NHTSA is focused on reducing fatality and injury 
risk for all motor vehicle occupants and addressing identified 
disparities expeditiously. NHTSA is taking several steps to address 
sex-based disparities in motor vehicle crash outcomes. Regarding 
requests for the use of expanded range of advanced crash test dummies 
and test surrogates, NHTSA developed and published a detailed plan on 
the development and implementation of advanced crash test dummies. This 
plan discusses the Agency's efforts to address the limitations of 
NHTSA's current test dummies to provide information relative to certain 
demographic groups, such as female and elderly vehicle occupants, and 
certain body regions, such as the lower extremities. NHTSA plans to 
incorporate advanced dummies into NCAP crash tests when the research is 
completed, necessary tools are available for implementation, and they 
meet the criteria for inclusion in NCAP. For example, since NHTSA has 
efforts underway to include the advanced 50th percentile male dummy, 
THOR-50M, into Federal regulation, the mid-term roadmap initiatives 
include using the THOR-50M in NCAP frontal impact crash tests. Since 
research is still underway regarding the advanced 5th percentile female 
dummy, THOR-05F, the NCAP long-term roadmap initiatives include adding 
the THOR-05F in frontal impact crash tests.
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    \445\ NHTSA Advanced Anthropomorphic Test Devices Development 
and Implementation Plan, March 2024, https://www.nhtsa.gov/sites/nhtsa.gov/files/2024-04/NHTSA-Advanced-Anthropomorphic-Test-Devices-Development-Implementation-041624-v1-tag.pdf.
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    Consistent with standard practice, NHTSA conducts ongoing 
evaluation of technological advances in anthropomorphic test devices 
available in global and domestic markets to determine whether the 
Agency should include those devices in NCAP and will continue to do so 
with respect to anthropomorphic test devices that would help address 
the identified sex-based disparities.
    While NHTSA primarily plans to update NCAP with new technologies 
and vehicle countermeasures, it will also consider removing existing 
evaluation programs found redundant due to regulations or that no 
longer effectively incentivize safety improvements.
    The roadmap outlined in this decision notice takes into 
consideration the aforementioned efforts, the input received from all 
stakeholders on the potential updates to NCAP, the readiness of the 
technologies, safety

[[Page 96078]]

potential, and the availability of objective and representative test 
procedures that can be applied to the U.S. vehicle fleet. NHTSA's NCAP 
roadmap for mid-term and long-term updates to the program are shown in 
Figures 18 and 19, respectively. This roadmap represents the current 
state of knowledge, and any safety opportunity or technology not 
included in this roadmap was omitted because it did not meet the four 
prerequisites for inclusion in NCAP at this time. In the next update to 
the roadmap, the addition of other technologies or safety programs 
would be subject to NHTSA's four prerequisites for inclusion in NCAP 
and the appropriateness of the technology or opportunity for a consumer 
information program.\446\
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    \446\ Though various commenters requested V2X technology be 
included in NCAP, NHTSA has not included it in the roadmap because 
of uncertainties in the deployment of cellular V2X technologies, the 
research needed to determine the safety potential of these 
technologies in light of other emerging technologies, including AEB 
for intersection crashes, and the need to develop test procedures 
for evaluating V2X technologies, including cybersecurity.
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    In general, the implementation timing of an update in NCAP ranges 
from 2 to 4 years from the time of publication of an RFC notice 
announcing the proposed update.

A. Mid-Term Updates to NCAP (2024-2028)

1. Updates to the Crash Avoidance Program
    In the near-term, NHTSA plans to finalize and implement the four 
additional ADAS technologies proposed in the 2022 NCAP RFC (LKA, BSW, 
BSI, and PAEB). NHTSA will identify vehicles with these recommended 
technologies by way of check marks on the NHTSA website starting in the 
fourth quarter of 2025 with model year 2026 vehicles. Until a crash 
avoidance rating system is developed and implemented, the check mark on 
the NHTSA website will remain the primary way of notifying consumers of 
available crash avoidance technologies meeting NHTSA's system 
performance criteria.
    NHTSA plans to complete research on rear automatic braking (RAB) 
\447\ in 2024 and plans to evaluate RAB systems in NCAP starting in the 
fourth quarter of 2027 with model year 2028 vehicles.
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    \447\ Though a number of commenters requested rear cross traffic 
warning (RCTW) be included in NCAP, NHTSA is not including 
evaluation of RCTW in NCAP at this time because the Agency's 
analysis of field data indicates that current RCTW systems have low 
safety benefits and are mainly associated with reduction in property 
damage crashes.
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2. Updates to the Crashworthiness Program
    As noted in the March 2022 NCAP RFC notice, NHTSA plans to use 
advanced crash test dummies with enhanced biofidelity (human-like 
response to impact loads) and injury assessment capabilities in current 
crash testing and any additional crash tests considered for the 
program. Mid-term updates to NCAP's crashworthiness program include:
     Using the THOR-50M instead of the HIII-50M in the NCAP 
frontal impact crash tests.
     Conducting a full-frontal rigid barrier crash test with 
the HIII-05F dummy in the driver seat.
    [cir] Equity in crash outcomes, including female occupant safety, 
is a priority for NHTSA. Since the advanced 5th percentile female 
frontal impact test dummy, THOR-05F, is currently under evaluation and 
refinement, it is not yet ready for implementation in NCAP crash tests. 
The THOR-05F is in the long-term update to NCAP in this roadmap. Until 
the THOR-05F dummy is implemented in NCAP, NHTSA will use the current 
HIII-05F dummy for assessing small female occupant risk in the driver 
seating position.
     Including a frontal oblique crash test using the THOR-50M.
    [cir] Given the enhanced biofidelity and instrumentation of the 
THOR-50M, especially for lower extremity injury prediction, testing 
with the THOR-50M in the frontal oblique crash test would help reduce 
the high rates of leg, foot, and ankle injuries seen in both females 
and males.\448\
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    \448\ Detailed analysis of field data suggests that when 
controlling for various factors, including crash speed and restraint 
use, female drivers have a higher risk of moderate lower extremity 
(leg and foot/ankle) injuries than male drivers in frontal crashes. 
Though the THOR-50M dummy is used for injury assessment, the 
countermeasures would also mitigate lower extremity injuries for 
50th percentile and larger female occupants.
---------------------------------------------------------------------------

     Replacing the ES-2re dummy with the WorldSID-50M dummy in 
the driver seat in the side impact Moving Deformable Barrier (MDB) 
crash test.
     Including the SID-IIs chest and abdomen deflections to 
assess overall injury potential in both the MDB crash test and the side 
pole impact test.\449\
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    \449\ This update would encourage countermeasures to reduce 
thoracic and abdominal injuries to small female occupants in side 
impact crashes. This is an interim upgrade to side impact protection 
for female occupants until the advanced 5th percentile female side 
impact test dummy, WorldSID-05F, is included in NCAP. The inclusion 
of WorldSID-05F in NCAP is a long-term update in this roadmap.
---------------------------------------------------------------------------

    NHTSA plans to implement the updated crashworthiness evaluation 
described above starting in the fourth quarter of 2027 with model year 
2028 vehicles. Implementation of the changes discussed will address 
comments received pertaining to the use of advanced crash test dummies, 
including those representing female occupants, as well as the 
incorporation of additional crash test conditions capturing frontal 
oblique impacts.
3. Updates to the VRU Safety Program
    As noted earlier, NHTSA plans to finalize the implementation of 
PAEB in the near term. NHTSA also plans to finalize in the near term 
the crashworthiness pedestrian protection proposed on May 26, 2023. The 
Agency will consider expanding the head impact test areas to include 
bicyclists' impact areas. NHTSA will include a check mark on the NHTSA 
website for PAEB and vehicle designs that meet the performance 
requirements in the NCAP crashworthiness pedestrian protection tests 
starting in the fourth quarter of 2025 with model year 2026 vehicles.
    In response to commenters requesting protection for additional 
VRUs, NHTSA has expedited its research for bicyclists and 
motorcyclists, and is currently developing and evaluating test 
procedures specific to the vehicle fleet and the crash scenarios and 
injury profiles of bicyclists and motorcyclists in the U.S. NHTSA plans 
to include evaluation of AEB for mitigating crashes with bicyclists and 
motorcyclists (along path crash scenarios) starting in the fourth 
quarter of 2027 with model year 2028 vehicles.
    Starting in the fourth quarter of 2024 with model year 2025 
vehicles, NHTSA plans to provide consumers with information obtained 
from vehicle manufacturers related to whether a vehicle is equipped 
with direct sensing technology and an alert system to mitigate 
heatstroke to unattended children in vehicles. By providing this 
information, which will be made available in the ``Safety Features'' 
section of the ratings page on the NHTSA website, NHTSA is taking 
initial steps to address comments received pertaining to rear seat 
occupant protection.
4. Rating Systems
    NHTSA intends to develop and propose crash avoidance and VRU safety 
rating systems, an updated crashworthiness rating system, and an 
overall safety rating system for each vehicle and seek public comment. 
NHTSA plans to develop the crash avoidance, crashworthiness, VRU 
safety, and overall safety rating system with the flexibility to allow 
for the addition of ratings of new technologies and vehicle

[[Page 96079]]

safety countermeasures, or for the removal of existing ones in a way 
that would not result in significant change to the rating systems. The 
final decisions on the crash avoidance, crashworthiness, and VRU safety 
rating system including overall vehicle rating are planned for 
completion in the third quarter of 2025 (crash avoidance), in the first 
quarter of 2026 (crashworthiness, VRU, overall vehicle safety) and 
implementation in NCAP in the fourth quarter of 2027 beginning with 
model year 2028 vehicles.
    NHTSA is currently conducting consumer research on approaches to 
display the crashworthiness, crash avoidance, VRU safety, and overall 
vehicle rating on the Monroney label. NHTSA plans to complete a 
rulemaking update to the Monroney label by the first quarter of 2026. 
NHTSA also plans to implement the new rating system, to include 
crashworthiness, crash avoidance, and VRU safety on the Monroney label 
and the NHTSA website, beginning in the fourth quarter of 2027 with 
model year 2028 vehicles.

B. Long-Term Updates to NCAP (2024-2033)

1. Updates to the Crash Avoidance Program
    NHTSA plans to include in NCAP the assessment of advanced lighting 
systems such as automatic driving beam (ADB), semi-automatic beam 
switching (SABS), and lower beam headlighting. NHTSA plans to implement 
the evaluation of advanced headlighting systems starting in the fourth 
quarter of 2030 with model year 2031 vehicles.
    NHTSA will conduct research to assess AEB performance in 
intersection crash scenarios such as left turn across path and straight 
crossing path conditions. After needed research is completed, the 
Agency plans to consider AEB evaluation in these intersection crash 
scenarios for inclusion in NCAP, with possible implementation starting 
in the fourth quarter of 2031 with model year 2032 vehicles. NHTSA will 
also consider further enhancement to the current finalized AEB 
evaluations by including additional scenarios and conditions, with 
implementation starting in the fourth quarter of 2032 with model year 
2033 vehicles.
    The Agency is conducting research on enhanced assessment of LKA 
systems to include evaluation at higher speeds, curved path, and/or 
road edge detection scenarios. After the research is completed, NHTSA 
will consider these enhanced evaluations of LKA systems in NCAP, with 
possible implementation starting in the fourth quarter of 2030 with 
model year 2031 vehicles. NHTSA is postponing its research on opposing 
traffic safety assist technology due to low fitment of this technology 
in vehicles and will consider its inclusion in the next update of the 
roadmap.
    NHTSA is researching various safe driving technologies, including 
driver monitoring systems to mitigate driver distraction and drowsy 
driving, and intelligent speed assist to mitigate crashes due to 
speeding. NHTSA will consider including intelligent speed assist in 
NCAP for occupant safety when the research on this technology is 
completed in 2028.\450\ NHTSA is considering implementation of certain 
other safe driving technologies starting in the fourth quarter of 2031 
with model year 2032 vehicles.
---------------------------------------------------------------------------

    \450\ Since NCAP is a consumer information program with 
voluntary participation by vehicle manufacturers, NHTSA needs to 
evaluate consumer acceptance of intelligent speed assist technology 
for improving occupant safety.
---------------------------------------------------------------------------

2. Updates to the Crashworthiness Program
    NHTSA is conducting research on the THOR-05F crash test dummy and 
is considering replacing the HIII-5F dummy in crash tests with the 
THOR-05F starting the fourth quarter of 2031 with model year 2032 
vehicles. At that time, NHTSA also plans to evaluate rear seat occupant 
protection using the THOR-05F, which will seek to address comments 
received regarding this topic.\451\
---------------------------------------------------------------------------

    \451\ While NHTSA has accelerated research on the THOR-05F 
dummy, uncertainties remain on federalizing the dummy and its 
implementation in crash testing. Therefore, NHTSA is considering its 
inclusion in NCAP in the long-term phase of the roadmap.
---------------------------------------------------------------------------

    NHTSA is still developing and evaluating the WorldSID-05F dummy and 
will consider its adoption into NCAP when research and rulemaking 
actions \452\ are complete. The Agency is considering replacing the 
SID-IIs dummy with the WorldSID-05F dummy in NCAP tests starting in the 
fourth quarter of 2033 with model year 2034 vehicles.
---------------------------------------------------------------------------

    \452\ The corresponding rulemaking action is the inclusion of 
WorldSID-05F in Part 572.
---------------------------------------------------------------------------

    As part of these efforts, NHTSA will also consider applying 
different injury criteria to data collected from the crash tests 
utilizing these new dummies to target performance thresholds that are 
more appropriate for older adults to address broader equity concerns.
3. Updates to the VRU Safety Program
    NHTSA plans to enhance AEB evaluation by including intersection 
crash scenarios (e.g., crossing path, left turn across path) for 
bicyclists and motorcyclists, with implementation starting in the 
fourth quarter of 2030 with model year 2031 vehicles. NHTSA will also 
consider further enhancement to the current finalized PAEB evaluations 
to incorporate additional test speeds, test scenarios, and VRUs (such 
as those representing wheelchairs, scooters, and diverse human 
attributes), with implementation starting in the fourth quarter of 2032 
with model year 2033 vehicles.
    NHTSA also plans to evaluate BSW and BSI to mitigate crashes with 
motorcyclists and bicyclists in multiple scenarios, with implementation 
starting in the fourth quarter of 2030 with model year 2031 vehicles.
    NHTSA plans to evaluate and include the advanced pedestrian legform 
impactor (aPLI, a newer pedestrian legform impactor with upper body 
mass and enhanced injury assessment capabilities), to assess 
crashworthiness pedestrian protection instead of the current FlexPLI (a 
flexible pedestrian legform impactor which lacks upper body mass). This 
VRU safety program update will be implemented starting in the fourth 
quarter of 2029 with model year 2030 vehicles.
    NHTSA is researching driver visibility to better understand the 
safety problem and scenarios associated with forward blind zones and 
front-over crashes to develop accurate and rigorous methods of 
evaluating driver's visibility. After the research is completed, NHTSA 
will consider inclusion of driver visibility in NCAP.
    By pursuing these efforts, the Agency will continue to work towards 
protecting those inside and outside the vehicle, as encouraged by 
public comments.
    NHTSA's NCAP roadmaps for mid-term and long-term updates to the 
program are shown in Figures 18 and 19, respectively. In these two 
figures, the timeframe of the research, RFC, and final decision phases 
are in calendar years. The start of the implementation phase, 
represented by a star, is with vehicle models of the proceeding 
calendar year.
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X. Economic Analysis

    The various changes in NCAP adopted in this final decision notice 
would enable the development of a new set of rating systems, which will 
expand the current rating system to include not only crashworthiness 
but also crash avoidance information and improve consumer awareness of 
ADAS safety features as well as encourage manufacturers to accelerate 
their adoption. This increased information to consumers and potential 
for accelerated adoption of ADAS would drive any economic and societal 
impacts that result from these changes and are thus the focus of this 
discussion of economic analysis. Hence, the Agency has considered the 
potential economic effects for ADAS technologies proposed for inclusion 
in NCAP and the potential benefit of introducing a rating system for 
ADAS technologies.
    Unlike crashworthiness safety features, where safety improvements 
are attributable to improved occupant protection when a crash occurs, 
the impact that ADAS technologies have on fatality and injury rates is 
a direct function of their effectiveness in preventing crashes or 
reducing the severity of the crashes they are designed to mitigate. 
This effectiveness is typically measured by using real-world 
statistical data, laboratory testing, or Agency expertise.
    With respect to vehicle safety, the Agency concludes, as discussed 
in detail in this notice, the adopted ADAS technologies have the 
potential to reduce vehicle crashes and crash severity. As cited in the 
RFC notice, researchers have conducted preliminary studies to estimate 
the effectiveness of ADAS technologies. Although these studies have 
been limited to certain models or manufacturers, which may not 
represent the entire fleet, they illustrate how these systems can 
provide safety benefits. Thus, although the Agency does not have 
sufficient data to determine the monetized safety impacts resulting 
from these technologies in a way similar to that frequently done for 
mandated technologies, when compared to the future without the proposed 
update to NCAP, NHTSA expects that these changes would likely have 
substantial positive safety effects by promoting earlier and more 
widespread deployment of these technologies.
    NCAP also helps address the issue of asymmetric information (i.e., 
when one party in a transaction is in possession of more information 
than the other), which can be considered a market failure. Regarding 
consumer information, the introduction of an upcoming new ADAS rating 
system is anticipated to provide consumers additional vehicle safety 
information (e.g., rating based on ADAS performance and capability as 
well as the types of ADAS in vehicles) as opposed to the information 
provided in the current program (e.g., check mark based on ADAS 
performance as pass/fail) to help them make more informed purchasing 
decisions by better presenting the performance of different ADAS 
technologies. The future ADAS rating would increase consumer awareness 
and understanding of the safety benefits in these technologies, and, in 
turn, incentivize vehicle manufacturers to offer the ADAS technologies 
that lead to higher ratings across a broader selection of their 
vehicles. Furthermore, as these ADAS technologies mature and become 
more reliable and efficient, a large portion of vehicles equipped with 
such systems would achieve higher ADAS ratings, and in turn consumers 
would have an increasing number of safer vehicles to choose from. There 
is an unquantifiable value to consumers in receiving accurate and 
comparable information about the safety performance of those 
technologies among manufacturers, makes, and models.
    IIHS/HLDI predicted that the number of vehicles equipped with ADAS 
technologies, including blind spot warning and lane departure warning, 
will increase substantially from 2020 to 2030 and reach near full 
market penetration in 2050.\453\ Although the Agency has limited data 
on costs of ADAS technologies to consumers, assuming consumer demand 
for safety remains high, the future ADAS rating system would likely 
accelerate the full adaptation of the ADAS technologies included in 
this notice. Nevertheless, the Agency does not have sufficient data, 
such as unit cost and information on how quickly full adaptation might 
be reached once an ADAS rating system is implemented, to predict the 
net increase in cost to consumers with a high degree of certainty.
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    \453\ Highway Loss Data Institute. (2023). Predicted 
availability of safety features on registered vehicles--a 2023 
update. Loss Bulletin, 40(2).
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XI. Appendix

    The Agency's final decision for AEB and PAEB testing in NCAP is 
generally similar to the standards for those technologies contained in 
the May 9, 2024, final rule establishing FMVSS No. 127. The two 
standards are based on the Agency's separate authorities and are 
intended to serve the distinct purposes of NCAP and the FMVSS. The 
Agency provides the below summary to assist readers in understanding 
the key areas of similarity and difference.
    With regard to vehicle AEB, the minimum and maximum subject vehicle 
(SV) test speeds and principal other vehicle (POV) test speeds for lead 
vehicle stopped (LVS), lead vehicle moving (LVM), and lead vehicle 
decelerating (LVD) crash imminent braking (CIB) and dynamic brake 
support (DBS) tests (as applicable) are the same in both NCAP and FMVSS 
No. 127, except for the minimum SV test speed for the LVS CIB test. For 
this LVS CIB test, the Agency has prescribed a minimum SV test speed of 
40 kph (24.9 mph) for NCAP, whereas a 10 kph (6.2 mph) minimum speed is 
specified in FMVSS No. 127. Further, both FMVSS No. 127 and NCAP impose 
a test passing criterion of ``no contact'' and stipulate conducting 
only one trial per test condition. Other specifications pertaining to 
test conduct such as SV accelerator pedal release timing and manual 
brake application timing are also identical for NCAP and FMVSS No. 127.
    There are various differences that exist with respect to the 
testing methods. For a given NCAP test scenario, the Agency will begin 
testing at the minimum prescribed test speed and will increase the test 
speed in 10 kph (6.2 mph) increments until the maximum test speed is 
reached. In comparison, FMVSS No. 127 permits testing at any speed 
within the speed range defined by the minimum and maximum test speeds. 
Similarly, for the LVD tests, NCAP and FMVSS No. 127 both establish 
minimum and maximum headways between 12 and 40 m (39.4 and 131.2 ft.) 
and POV deceleration between 0.3 and 0.5g, but NCAP will only conduct 
tests at those minimum and maximum values, while the FMVSS No. 127 
permits testing at any headway within the range.
    In addition, while both FMVSS No. 127 and NCAP will evaluate FCW 
functionality during AEB testing, and the requirements for the timing 
of the FCW alert as well as the necessary alert modalities (i.e., 
visual and auditory signals) are identical, FMVSS No. 127 imposes 
additional FCW alert specifications, including auditory signal 
intensity and visual symbol color and location requirements. Further, 
FMVSS No. 127 allows for a wider variety of vehicle test devices, as 
any device that complies with certain specifications defined in ISO 
19206-3:2021 \454\ is

[[Page 96083]]

permitted, whereas the Agency has adopted a particular device (Revision 
G of the ABD GVT) that meets the requirements of the ISO standard for 
NCAP's AEB testing. Finally, the pass-through false positive test is 
included in FMVSS No. 127 but has not been adopted for NCAP.
---------------------------------------------------------------------------

    \454\ ``Road vehicles--Test devices for target vehicles, 
vulnerable road users and other objects, for assessment of active 
safety functions--Part 3: Requirements for passenger vehicle 3D 
targets, Edition 1, 2021-05.''
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    Many of the PAEB testing requirements adopted for FMVSS No. 127 are 
also identical to those adopted for NCAP. In particular, the same test 
scenarios and pedestrian test mannequins are specified for the two 
initiatives, and the mannequin travel speeds align for all test 
conditions. Minimum and maximum SV speeds are also the same for test 
conditions S1a, S1b, S1e, and S4c during daylight testing and for S1b 
and S4c during darkness testing.
    For other test conditions, though, the minimum and maximum SV 
travel speeds for the FMVSS and NCAP do not align. In particular, for 
daylight testing, NCAP imposes an upper test speed of 60 kph (37.3 mph) 
for the S1d test condition, whereas FMVSS No. 127 has established an 
upper test speed of 50 kph (31.1 mph). Similarly, for S4a, NCAP has 
adopted a maximum test speed of 60 kph (37.3 mph), whereas 55 kph (34.2 
mph) has been adopted in FMVSS No. 127. For darkness testing, NCAP has 
established a maximum test speed of 60 kph (37.3 mph) for the S4a test 
condition, whereas FMVSS No. 127 specifies an upper test speed of 55 
kph (34.2 mph) for this test condition. FMVSS No. 127 has also imposed 
65 kph (40.3 mph) as the upper test speed for S4c, while NCAP has 
adopted a maximum test speed of 60 kph (37.3 mph) for this test 
condition.
    Other differences between FMVSS No. 127 and NCAP's PAEB testing 
requirements exist for darkness testing. While NCAP, like FMVSS No. 
127, will require testing in darkness, NCAP will not conduct separate 
performance assessments for both the SV's lower and upper beam 
headlamps and, instead, will only engage the vehicle's lower beams. 
Furthermore, FMVSS No. 127 does not require darkness testing for PAEB 
test conditions S1a, S1d, and S1e, whereas such testing is specified 
for NCAP.
    The overall test requirements and test conduct for PAEB are also in 
general alignment, as both FMVSS No. 127 and NCAP include a passing 
criterion of ``no contact'' and stipulate conducting only one trial per 
test condition. As with vehicle AEB, though, for a given NCAP test 
scenario, the Agency will begin testing at the minimum prescribed test 
speed and will then increase the test speed in 10 kph (6.2 mph) 
increments until the maximum test speed is reached, while FMVSS No. 127 
permits testing at any speed within the speed range.

    Issued in Washington, DC, under authority delegated in 49 CFR 
1.95 and 501.
Adam Raviv,
Chief Counsel.
[FR Doc. 2024-27447 Filed 12-2-24; 8:45 am]
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