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

Federal RegisterFeb 22, 2022

Ask Donna

What actually matters in this document.

Text

DEPARTMENT OF TRANSPORTATION

National Highway Traffic Safety Administration

49 CFR Part 571

[Docket No. NHTSA-2022-0013]

RIN 2127-AL83

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

AGENCY:

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

ACTION:

Final rule.

SUMMARY:

This document amends NHTSA's lighting standard to permit the certification of adaptive driving beam (ADB) headlamps. ADB headlamps utilize technology that actively modifies a vehicle's headlamp beams to provide more illumination while not glaring other vehicles. The requirements adopted today are intended to amend the lighting standard to permit this technology and establish performance requirements for these systems to ensure that they operate safely. ADB has the potential to reduce the risk of crashes by increasing visibility without increasing glare. The agency initiated this rulemaking in response to a petition for rulemaking from Toyota Motor North America, Inc.

DATES:

Effective date:

The effective date of this final rule is February 22, 2022. The incorporation by reference of certain publications listed in the rule was approved by the Director of the Federal Register as of February 6, 2012.

Compliance date:

The compliance date for the amendments in this final rule is February 22, 2022.

Petitions for reconsideration:

Petitions for reconsideration of this final rule must be received not later than April 8, 2022.

ADDRESSES:

Petitions for reconsideration of this final rule must refer to the docket and notice number set forth above and be submitted to the Administrator, National Highway Traffic Safety Administration, 1200 New Jersey Avenue SE, Washington, DC 20590. Note that all petitions received will be posted without change to

www.regulations.gov,

including any personal information provided.

Privacy Act:

Please see the Privacy Act heading under Rulemaking Analyses and Notices.

FOR FURTHER INFORMATION CONTACT:

Mr. Markus Price, NHTSA Office of Crash Avoidance Standards. Telephone: 202-366-1810; Email:

Markus.Price@dot.gov;

or Mr. John Piazza, Office of Chief Counsel. Telephone: 202-366-2992; Email:

John.Piazza@dot.gov.

You may send mail to these officials at: National Highway Traffic Safety Administration, 1200 New Jersey Avenue SE, Washington, DC 20590.

SUPPLEMENTARY INFORMATION:

Table of Contents

I. Executive Summary

II. Background and Safety Need

III. NHTSA's Statutory Authority

IV. ADB Rulemaking Mandate in the Infrastructure, Investment and Jobs Act

V. Summary of the NPRM

VI. Overview of Comments

VII. NHTSA Research and Testing

VIII. Final Rule and Response to Comments

A. Summary of the Final Rule and Modifications to the NPRM

B. Interpretation of FMVSS No. 108 as Applied to ADB Systems

C. Track Testing Requirements and Procedures

1. Practicability of Proposed Test Scenarios

2. Test Fixtures vs. Stimulus Vehicles

3. Justification for Testing on Curves and General Approach for Scenario Selection

4. Maximum Illuminance Criteria (Glare Limits)

5. ADB Adaptation Time

6. Test Fixture Specifications

7. Test Fixture Placement

8. Test Scenarios

a. Scenario 1: Oncoming Straight

b. Scenario 2: Oncoming Small Left Curve

c. Scenario 3: Oncoming Medium Left Curve

d. Scenario 4: Oncoming Large Left Curve

e. Scenario 5: Oncoming Medium Right Curve

f. Scenario 6: Oncoming Large Right Curve

g. Scenario 7: Preceding Straight

h. Scenario 8: Preceding Medium Left Curve

i. Decision Not To Include Oncoming Short Right Curve Scenario

9. Other Test Parameters and Conditions

a. Radius of Curvature

b. Test Vehicle Speed and Acceleration

c. Headlamp Aim

d. Road Surface

e. Ambient and Reflected Light

f. Superelevation

g. Lane Divisions

h. Hills

10. Data Acquisition and Measurement

a. Photometers

b. Sampling Rate

c. Noise and Filtering

d. Allowance for Momentary Glare Exceedances

e. Vehicle Pitch

11. Repeatability

D. Laboratory (Component-Level) Testing

1. Need for Laboratory Testing

2. Definitions of Areas of Reduced and Unreduced Intensity

3. Requirements for Area of Reduced Intensity

4. Requirements for Area of Unreduced Intensity

5. Transition Zone

6. Veiling Glare

E. Minimum Activation Speed

F. Operator Controls, Indicators, Malfunction Detection, and Operating Instructions

G. Accommodation of Different Technologies

H. Requirements for Semiautomatic Beam Switching Devices Other Than ADB and Applicability of Compliance Options

I. Physical Test Requirements

J. Other Requirements

K. Information Reporting

L. Aftermarket Compliance

M. Exemption Petitions

N. Compliance Date

O. Regulatory Alternatives

P. Overview of Benefits and Costs

IX. Appendix to FMVSS No. 108 (Table of Contents)

X. Rulemaking Analyses and Notices

Appendix A. Comparison of Oncoming Glare Limits to Table XIX Right-Side Photometric Maxima

Appendix B. Example of Laboratory Photometric Testing of Adaptive Driving Beam

Appendix C. ADB Performance With Motorcycle Test Fixture

Appendix D. List of Comments Cited in Preamble

I. Executive Summary

This final rule amends Federal Motor Vehicle Safety Standard (FMVSS or Standard) No. 108, “Lamps, reflective devices, and associated equipment,” to enable the certification of adaptive driving beam (ADB) headlighting systems on vehicles sold in the United States. NHTSA is issuing this final rule under the National Traffic and Motor Vehicle Safety Act (Safety Act), 49 U.S.C. Chapter 301, Motor Vehicle Safety (49 U.S.C. 30101

et seq.

Glare, Visibility, and Adaptive Driving Beam Technology

Adaptive driving beam headlamps utilize technology that actively modifies the headlamp beams to provide more illumination while not glaring other vehicles. The requirements adopted today are intended to amend FMVSS No. 108 to permit this technology and ensure that it operates safely.

Vehicle headlamps must satisfy two different safety needs: Visibility and glare prevention. The primary function of headlamps is to provide forward visibility for drivers. At the same time, there is a risk that intense headlamp illumination may be directed towards oncoming or preceding vehicles. Such illumination, referred to as glare, can reduce the ability of other drivers to see and can cause discomfort. Headlighting has therefore traditionally entailed a tradeoff between long-distance visibility and glare prevention. This is reflected in Standard No. 108's requirement that

headlighting systems have both upper and lower beams. The existing headlamp requirements regulate the beam pattern (photometry) of the upper and lower beams; they ensure sufficient visibility by specifying minimum amounts of light in certain areas on and around the road, and prevent glare by specifying maximum amounts of light in directions that correspond to where oncoming and preceding vehicles would be.

ADB systems are an advanced type of headlamp technology that optimizes beam patterns without driver action. Semiautomatic beam switching technology was first introduced on vehicles in the United States in the 1950s and has become increasingly popular in the last few decades. The semiautomatic beam switching technology currently available in the United States (commonly referred to as “auto hi-beam” or “high beam assist”) automatically switches between the lower and upper beams. This provides safety benefits because research has shown that most drivers underutilize the upper beams, and semiautomatic beam switching facilitates increased upper beam use in situations where drivers of other vehicles will not be glared.

ADB systems are an improvement over “auto hi-beam” technology currently available in the United States because they are capable of providing more illumination than a lower beam without increasing glare. When operating in automatic mode, instead of simply switching between the upper and lower beams, an ADB system is able to provide a dynamic, adaptive beam pattern that changes based on the presence of other vehicles or objects, providing less illumination to occupied areas of the road and more illumination to unoccupied areas of the road. ADB systems can therefore provide more illumination than existing lower beams without glaring other motorists (if operating correctly). ADB systems achieve this enhanced performance by utilizing advanced sensors, data processing software, and headlamp hardware.

ADB systems are available in foreign markets but are not currently offered on vehicles in the United States. This final rule amends FMVSS No. 108 to permit ADB systems on vehicles in the United States and ensure that they operate safely. ADB, like other headlamp technologies, implicates the twin safety needs of visibility and glare prevention. This final rule does three main things that, taken together, allow ADB systems and ensure that they meet these safety needs.

First, it amends FMVSS No. 108 to allow ADB systems. It amends, among other things, the existing headlamp requirements so that ADB technology is permitted.

Second, this final rule adopts requirements to ensure that ADB systems do not increase glare to other motorists beyond current lower beams. ADB systems are capable of providing a variable, adaptive beam in the presence of other vehicles that provides more illumination than the currently allowed lower beam. However, if ADB systems do not accurately detect other vehicles on the road and shade them accordingly, other motorists will be glared.

The rule addresses this safety need by including vehicle-level track-test requirements specifically tailored to evaluate whether an ADB system functions safely and limits glare for other motorists.

NHTSA is sensitive to concerns about glare due to the numerous complaints from the public it has received and its own research (prompted, in part, by these complaints and a 2005 Congressional mandate to study the risks from glare).

Third, it adopts component-level laboratory-tested requirements related to both glare and visibility, as well as a limited set of other system requirements, such as requirements for manual override and fail-safe operation.

In drafting this final rule, NHTSA considered two major regulatory alternatives. One was the Economic Commission for Europe (ECE) regulations that apply to ADB systems, including a vehicle-level test on public roads. However, the ECE road test is not appropriate for adoption as an FMVSS because it does not provide sufficiently objective performance criteria. We also considered a Society for Automotive Engineers (SAE) recommended practice, J3069 JUN2016, Surface Vehicle Recommended Practice; Adaptive Driving Beam, as well as the updated version of this practice (published in March 2021). The final rule follows SAE J3069 in many significant respects, but also differs from it in significant ways.

NHTSA published the notice of proposed rulemaking (NPRM) preceding this final rule on October 12, 2018 (83 FR 51766). Many industry comments to the NPRM urged closer harmonization with SAE J3069. These comments focused primarily on costs from dis-harmonization due to the resulting need for market-specific hardware and components. In response to the comments, NHTSA conducted additional vehicle-level testing to validate modifications to the proposal to harmonize more closely with SAE J3069 while still retaining sufficient realism. As a result, NHTSA has changed some aspects of the proposal. The final rule more closely conforms to SAE J3069 in a number of respects but continues to deviate from it for reasons discussed in detail in this preamble.

Differences Between This Final Rule and the Proposal

The following discussion highlights the more noteworthy differences between the final rule and the NPRM. All changes from the proposal are discussed in the appropriate sections of this preamble.

Vehicle-Level Track Test To Evaluate Glare

Stimulus test fixtures instead of stimulus vehicles.

The final rule specifies test fixtures instead of stimulus vehicles. This change will result in a less complex test that is more closely harmonized with SAE J3069, while still ensuring that ADB systems operate safely. While the test fixture specifications follow SAE J3069 with respect to the locations of the photometers and stimulus lamps, the final rule requires the use of more real-world representative lighting in the compliance test by specifying original equipment vehicle headlamps and taillamps.

More efficient test scenarios.

The final rule simplifies the number and complexity of test scenarios. The final rule continues to differ from SAE J3069 by specifying test scenarios with actual curves because this is necessary to evaluate how an ADB system would perform in the real world. We have, however, modified many of the curved-path test scenarios. NHTSA believes that the final scenarios meet the need for motor vehicle safety by containing a broad range of realistic road geometries and vehicle interactions.

Data measurement and allowances.

The final rule changes how NHTSA will measure and evaluate ADB system illuminance. This includes an added specification for a data filter and replacing the proposed International Roughness Index parameter with an explicit adjustment for vehicle pitch.

Component-Level Laboratory Photometric Testing

The final rule retains, in modified form, the proposed requirements for component-level laboratory testing.

Defining “adaptive driving beam” as a new beam type.

The final rule defines a new beam type, “adaptive driving beam.” The final rule also provides manufacturers flexibility to determine when to provide an area of reduced or unreduced intensity (subject to several requirements or constraints, such as the

track test that evaluates glare). This will enable systems to provide an area of reduced intensity not only to prevent glare to oncoming or preceding vehicles, but also in other situations in which reduced intensity would be beneficial.

Requirements for areas of reduced intensity.

The final rule follows the NPRM and specifies the existing lower beam photometric test points (both minima and maxima). The minima are important because the final rule does not include any “false positive” tests to ensure that an ADB system does not mistakenly dim the beam in the absence of other vehicles, and the maxima are necessary to help ensure that other motorists are not subject to glare beyond that experienced with lower beams.

Requirements for areas of unreduced intensity.

The final rule follows the NPRM and specifies the existing upper beam photometric test points (both minima and maxima). Requiring a minimum level of illumination is important to ensure a minimum level of visibility. The final rule does not adopt the higher ECE upper beam maxima.

Transition zone.

The final rule allows for a 1-degree transition zone between an area of reduced intensity and an area of unreduced intensity. The lower and upper beam photometric test points will not apply within a transition zone (except for the upper beam maximum at H-V, which still applies). Manufacturers essentially will be free to determine the areas of reduced and unreduced intensity and, therefore, the boundaries of the transition zone.

Other System Requirements

The final rule retains many of the proposed system requirements. However, the minimum activation speed has been decreased from 25 mph to 20 mph to give greater flexibility to manufacturers wishing to provide for hysteresis in the system design. The final rule also exempts ADB systems from many of the vehicle headlamp aiming device requirements, which would add unnecessary costs to ADB systems.

Benefits and Costs

This final rule is not significant and so was not reviewed by OMB under E.O. 12866. NHTSA has determined that quantifying the benefits and costs is not practicable in this rulemaking because of limitations on the agency's ability to accurately estimate the target population and the effectiveness of ADB. We have, however, identified the problem this rule is intended to address, considered whether existing regulations have contributed to the problem, qualitatively assessed the costs and benefits, and considered alternatives. This final rule appropriately balances the needs for visibility and glare prevention, and adopts requirements that are both practicable and sufficient to assess whether an ADB system operates safely. This final rule does not require manufacturers to provide ADB systems, but only specifies the requirements the systems must meet if equipped on vehicles.

II. Background and Safety Need

On October 12, 2018, NHTSA published the NPRM (83 FR 51766) underlying this final rule. NHTSA is publishing this final rule to set forth the amendments to FMVSS No. 108 (49 CFR 571.108), summarize the comments received in response to the proposal, and provide the agency's responses to those comments.

This section provides a brief introduction to the safety needs addressed in this rulemaking, ADB technology, the relevant industry and international standards for ADB systems, the petition for rulemaking that prompted the NPRM, and related exemption petitions and NTSB recommendations. For additional detailed background information (including an explanation of the headlamp photometric requirements and regulatory history and research efforts related to glare), the reader is referred to the NPRM.

See

pp. 51768-51774.

Safety Needs: Visibility and Glare Prevention

Vehicle headlamps primarily satisfy two safety needs: Visibility and glare prevention. Headlamps illuminate the area ahead of the vehicle and provide forward visibility.

Headlamp illumination, however, has the potential to glare other motorists. Accordingly, headlighting systems have traditionally consisted of lower beams and upper beams. The lower beams (also referred to as passing beams or dipped beams) are designed to provide relatively high levels of light in the close-in forward visibility region, and to provide reduced light intensity in longer-distance regions, where oncoming or preceding vehicles would be glared. The lower beams are intended for use during lower-speed driving or when meeting or closely following another vehicle. Upper beams (also referred to as high beams, main beams, or driving beams) are designed to provide relatively high levels of illumination in both close-in and longer distance regions. They are intended primarily for distance illumination and for use when not meeting or closely following another vehicle. (FMVSS No. 108 establishes maximum levels of intensity the upper beam may not exceed.)

They also make the vehicle more visible to other road users.

Visibility and glare are both related to motor vehicle safety. Visibility has an obvious, intuitive relation to safety: The better drivers can see the road, the better they can react to road conditions and obstacles to avoid crashes. Although the qualitative connection to safety is intuitive, quantifying the effect of visibility on crash risk is difficult because of many confounding factors (for example, was a late-night crash caused by diminished visibility or driver fatigue?). Still, evidence suggests that diminished visibility likely increases the risk of crashes, particularly crashes at higher speeds involving pedestrians, animals, trains, and parked cars.

The NPRM (in Appendix A) included an analysis estimating the target population that could benefit from the increased visibility provided by ADB systems.

Nighttime Glare and Driving Performance, Report to Congress (2007), National Highway Traffic Safety Administration, Department of Transportation [hereinafter “2007 Report to Congress”], p. 6. A 2016 study by the Insurance Institute for Highway Safety noted that “[t]wenty-nine percent of all fatalities during 2014 occurred in the dark on unlit roads. Although factors such as alcohol impairment and fatigue contributed to many of these crashes, poor visibility likely also played a role.” Ian J. Reagan, Matthew L. Brumbelow & Michael J. Flannagan. 2016. The Effects of Rurality, Proximity of Other Traffic, and Roadway Curvature on High Beam Headlamp Use Rates. Insurance Institute for Highway Safety, pp. 2-3 (citations omitted).

See also

77 FR 40843 (July 11, 2012) (request for comments on the report).

Elizabeth Mazzae, G.H. Scott Baldwin, Adam Andrella, & Larry A. Smith. 2015. Adaptive Driving Beam Headlighting System Glare Assessment, DOT HS 812 174. Washington, DC: National Highway Traffic Safety Administration (NHTSA-2018-0090-0003).

See

NPRM, pp. 51773-51774.

Research After the NPRM

After reviewing the comments on the NPRM, NHTSA explored opportunities to modify the proposal to resemble SAE J3069 more closely, while at the same time retaining a sufficient degree of realism the agency believes the SAE standard lacks. Most significantly, NHTSA explored using stationary test fixtures instead of dynamic stimulus vehicles. NHTSA developed and fabricated test fixtures that were similar to the fixtures specified in SAE J3069 but differed in some important respects (this is discussed below). NHTSA developed a modified version of the NPRM test procedure (including a simplified set of test scenarios) using the test fixtures. NHTSA then carried out a series of preliminary and full-scale vehicle tests to develop and validate those test procedures. Those test procedures are the same test procedures specified in this final rule. The research also documented testing details to support the laboratory test procedure manual that will be used by NHTSA's Office of Vehicle Safety Compliance (OVSC).

The OVSC laboratory procedures are not part the regulatory text. Published separately by OVSC, they are intended to provide laboratories contracted by NHTSA with additional guidelines for obtaining compliance test data.

NHTSA used the following three vehicles in the test program.

• 2019 Ford Fusion equipped with FMVSS-certified halogen headlamps;

○ Selected because it was a high-sales vehicle with halogen headlamps compliant with FMVSS No. 108, and the vehicle was readily available at NHTSA's Vehicle Research and Testing Center (VRTC).

• 2016 Volvo XC90 equipped with FMVSS-certified LED headlamps;

○ Selected because it was equipped with LED headlamps rated “Acceptable” by IIHS, and the vehicle was readily available at NHTSA's VRTC.

• 2018 Lexus NX300 (European mass production model) equipped with ADB LED headlamps modified by the manufacturer to be consistent with a visually optically aligned right (VOR) beam pattern used in the United States.

○ Selected because it was equipped with an ADB system, modified to project lower and upper beam patterns compliant with FMVSS No. 108.

Preliminary Test Development and Validation

NHTSA created a test fixture to accommodate both the NHTSA and SAE test procedures. The test fixture positioned a vertical array of illuminance meter light sensors (

i.e.,

receptor heads) in specified positions and provided accurate positioning for the various NHTSA and SAE lamp configurations. The configurations included stimulus lamps specified in today's final rule: MY 2018 Ford F-150 headlamps and taillamps, MY 2018 Toyota Camry headlamps and taillamps, and a MY 2018 Harley Davidson motorcycle taillamp,

and the lamps

specified in SAE J3069 intended to simulate headlamps and taillamps. This single test fixture was able to accommodate needed light sensor configurations for both oncoming and same direction test scenarios.

To represent a motorcycle headlamp, this testing used a 5.75 inch bullet headlamp kit from a 2018 Harley Davidson Roadster using an HB2 replaceable light source (part #68593-06). After this testing and before the publication of this final rule,

that part went out of production and has been replaced with part #68297-05B.

As an important initial step as part of the research, NHTSA evaluated the stability of the measured illuminance values without a test vehicle present to determine the level of noise (if any) in the measurement system that was not dependent on the vehicle being tested. For each stimulus lamp condition, illuminance data were recorded for a period of 30 seconds in typical test conditions. The results indicated that both the analog and digital data, measured at frequency over time, demonstrated low standard deviations for each of the receptor heads for each of the ten test lamp conditions, suggesting very little system noise or fluctuation from ambient conditions. In fact, each lamp condition had at least two receptor heads that exhibited no variability (standard deviation = 0) in the digital data. Thus, the illuminance meter outputs appeared to be stable.

Testing of the three vehicle models with headlighting systems operating in lower beam mode showed that the measurement system and the headlamp types tested, halogen and LED, were compatible with the test equipment (

i.e.,

no abnormalities in measurements were observed based upon the type of headlighting system).

NHTSA performed tests to assess whether test scenarios could be executed with sufficiently steady vehicle dynamics such that, in lower beam mode, headlamp illumination measured during the dynamic test scenario would match that measured in the same location with the vehicle stationary. Measured illuminance and pitch data values were extracted for both dynamic and static test trials at specific scenario path points corresponding to an end of a glare limit distance range. This study found that dynamically-influenced variation was not a major contributor to variability in the test. Pitch was found to have a major influence on illuminance measurements; however, the sources of pitch variance were primarily static in nature (resulting from waviness in the track pavement) and not dynamic (acceleration, or dynamic oscillations).

Full-Scale Validation Testing

After successfully completing this preliminary evaluative testing, NHTSA proceeded to validate the final test procedure by performing three sets of full-scale tests.

In the first set of tests, the ADB-equipped Lexus NX300 was subjected (in ADB mode) to the final rule test procedure as well as the SAE test procedure. We also evaluated ADB system performance using a full F-150 vehicle as a stimulus instead of a test fixture. In general, the ADB system installed on the tested vehicle responded similarly to the test fixture as it did to the full stimulus vehicle.

In the second set of tests, the agency subjected all three test vehicles with headlighting systems operating in lower beam mode to the NHTSA ADB test procedure. Measured illuminance values were evaluated with respect to the glare limit criteria. The lower beams of the Ford Fusion had passing results below the glare limits in all test scenarios, while the lower beams of the Lexus NX300 did not pass several of the test scenarios when illuminance values were compared to the glare limits. The Volvo lower beams performed well under the limits for the straight and left curve scenarios, but exceeded the limits finalized today for the right curves.

In the third set of validation tests, the agency conducted a series of tests using the 2016 Volvo XC90 with the lower beams activated to determine the repeatability of measured illuminance values and test outcomes for both the final rule and SAE test procedures. Testing involving multiple runs of each test scenario was conducted to permit different types of repeatability analyses, including same night (gauge); different night (test procedure); and different headlamp aiming technician (reproducibility). The repeated testing was performed to support an assessment of the repeatability of measured illuminance values and test outcomes for the final rule's ADB test procedure (as well as the SAE test procedure). A summary of the agency's repeatability analysis is presented in Section VIII.C.11. The full results of NHTSA's test procedure repeatability and reproducibility analyses are detailed in the repeatability report docketed with this final rule.

The test procedures reported in that document are the same as the procedures used in the first and second sets of validation tests described above. NHTSA is also docketing a full test report more fully describing the agency's testing.

Mazzae, E.N., Baldwin, G.H.S., Satterfield, K., & Browning, D.A. 2021. Adaptive Driving Beam Headlamps Test Repeatability Assessment. Washington, DC: National Highway Traffic Safety Administration.

Mazzae, E.N., Baldwin, G.H.S., Satterfield, K., Browning, D.A., & Andrella, A.T. 2021. Adaptive Driving Beam Headlighting Systems Rulemaking Support Testing. Washington, DC: National Highway Traffic Safety Administration.

VIII. Final Rule and Response to Comments

A. Summary of the Final Rule and Modifications to the NPRM

The major components of the final rule are summarized below, including the most significant differences between the final rule and the NPRM. Less significant changes are discussed in the appropriate sections of the preamble.

Vehicle-Level Track Test To Evaluate Glare

The final rule retains the track test but departs from the proposal in a few ways.

Stimulus test fixtures instead of stimulus vehicles.

The final rule specifies the use of test fixtures instead of stimulus vehicles. This change will result in a less complex test more closely harmonized with SAE J3069, while still ensuring that ADB systems operate safely. While the test fixture specifications follow the SAE J3069 specifications with respect to the locations of the photometers and stimulus lamps, the final rule requires the use of more real-world representative lighting by specifying original equipment vehicle headlamps and taillamps.

More efficient test scenarios.

The final rule substantially simplifies the number and complexity of test scenarios. Because the final rule specifies stimulus test fixtures and not stimulus vehicles, all scenarios involving a moving stimulus vehicle (

e.g.,

passing scenarios) were eliminated. While the final rule retains oncoming and preceding scenarios

with a curved test path, the agency modified the measurement distances and eliminated some scenarios entirely because they were deemed unnecessary. With respect to oncoming scenarios, the straight and large left curve scenarios are retained essentially as proposed, and the short-radius right curve scenario has been eliminated. The final rule retains scenarios with other proposed curves but truncates the distances at which ADB illuminance is evaluated. With respect to preceding glare scenarios, the final rule retains (with truncated measurement distances) the straight and medium left curve scenarios. These modifications, summarized in Table 4, respond to comments that expressed concern about the complexity of the proposed testing. NHTSA believes that

the finalized test scenarios meet the need for motor vehicle safety by containing a broad range of realistic road geometries—including curves—and vehicle interactions while addressing possible redundancies.

The final rule regulatory text uses the terms “same direction” and “opposite direction” to reflect that the final rule uses fixtures and not stimulus vehicles.

Table 4—Summary of Modifications to the Proposed Track Test Scenarios

NPRM

NPRM test #

Measurement

distance

(m)

Stimulus

vehicle

speed

(mph)

Test vehicle speed

(mph)

Radius

(size-

direction)

Final rule

Final

test #

Measurement

distance

(m)

Test

vehicle

speed

(mph)

Radius

(size-

direction)

Oncoming (adjacent lane):

15-220

60-70

Straight

Dropped

15-220

60-70

Straight

15-220

60-70

Straight

15-220

25-30

Small—R

Dropped

15-220

25-30

Small—L

15-220

25-30

Small—R

15-220

25-30

Small—L

15-59.9

25-30

Small—L

15-220

40-45

Med—R

Dropped

15-220

40-45

Med—L

15-220

40-45

Med—R

15-50

40-45

Med—R

15-220

40-45

Med—L

15-150

40-45

Med—L

11a

15-220

50-55

Large—R

Dropped

11b

15-220

50-55

Large—L

N/A

15-70

50-55

Large—R

N/A

15-220

50-55

Large—L

Same Direction Same Lane:

15-220

60-70

Straight

Dropped

15-220

25-30

Small—L

15-220

25-30

Small—R

15-220

40-45

Med—L

15-220

40-45

Med—R

11a

15-220

50-55

Large—L

11b

15-220

50-55

Large—R

Same Direction Adjacent Lane Fast ADB:

15-119.9

60-70

Straight

15-100

60-70

Straight

15-119.9

40-45

60-70

Straight

Dropped

15-119.9

25-30

Small—R

15-119.9

25-30

Small—L

15-119.9

40-45

Med—R

15-119.9

40-45

Med—L

15-100

40-45

Med—L

15-119.9

30-35

40-45

Med—R

Dropped

15-119.9

30-35

40-45

Med—L

13a

15-119.9

40-45

50-55

Large—R

13b

15-119.9

40-45

50-55

Large—L

Same Direction Fast Stimulus:

30-119.9

60-70

40-45

Straight

Dropped

Data measurement and allowances.

The final rule makes some changes to how NHTSA will measure and evaluate ADB system illuminance. NHTSA has added a specification for a data filter. It has deleted the proposed International Roughness Index parameter and replaced it with an explicit adjustment for vehicle pitch. The proposed 0.1 second (or 1 m) allowance for momentary glare exceedances has been modified by deleting the distance component and more clearly specifying how this adjustment will be applied. The final rule also includes additional specifications for the photometer.

Small = 98 m-116 m; Med = 223 m-241 m; Large = 335 m-396 m.

Small = 85 m-115 m; Med = 210 m-250 m; Large = 335 m-400 m.

Component-Level Laboratory Photometric Testing

The final rule retains the proposed requirements for component-level laboratory testing but has modified them to give manufacturers greater design flexibility.

Defining “adaptive driving beam” as a new beam type.

The final rule defines a new beam type, an “adaptive driving beam,” as “a beam consisting of area(s) of reduced intensity, unreduced intensity, and transition zone(s).” We eliminated the proposed regulatory text that referred to an area of reduced intensity as being “designed to be directed towards oncoming or preceding vehicles” and to an area of unreduced

intensity as being directed “in other directions.” The final rule is intended to provide manufacturers flexibility to decide which portions of the roadway will receive an area of reduced or unreduced intensity, subject to several requirements or constraints (such as the track test that evaluates glare). This will enable systems to provide an area of reduced intensity not only to prevent glare to oncoming or preceding vehicles, but also in other situations in which reduced intensity would be beneficial (for example, towards retroreflective signs, or on a wet roadway).

Transition zone.

In response to comments, the final rule also allows for a 1-degree transition zone between an area of reduced intensity and an area of unreduced intensity.

Requirements for areas of reduced intensity.

The final rule retains the requirement that an area of reduced intensity not exceed the lower beam maxima in order to help ensure that other motorists are not subject to glare. It also continues to require that an area of reduced intensity meet the lower beam minima; NHTSA believes this requirement is important because neither the proposal nor the final rule include any “false positive” tests to ensure that an ADB system does not mistakenly dim the beam in the absence of any oncoming or preceding vehicles.

Requirements for areas of unreduced intensity.

The final rule follows the NPRM and specifies the existing upper beam minima and maxima. In response to comments that suggested not specifying the upper beam minima in this area (in order to allow less illumination in situations in which it would be appropriate, such as towards a retroreflective sign), we have, as explained above, eliminated the proposed regulatory text that implied that an area of unreduced intensity should be directed towards areas of the roadway not occupied by other vehicles. This will allow manufacturers to design systems that provide an area of reduced intensity to areas of the road that are not occupied by other vehicles but for which it may be appropriate to provide less illumination than would be required by the upper beam minima.

As was proposed, the final rule does not adopt the higher ECE upper beam maxima. While NHTSA agrees with the commenters that higher intensity upper beams might lead to potential safety benefits in the form of increased visibility in the absence of other road users, the agency remains concerned about the associated potential safety disbenefits, due to increased glare, that might result from higher intensity upper beams, particularly in situations in which an ADB system might not recognize and shade other vehicles.

Other System Requirements

ADB minimum activation speed.

The final rule retains a minimum activation speed but this has been decreased from 25 mph to 20 mph to give greater flexibility to manufacturers wishing to provide for hysteresis in the system design.

Exemption from some horizontal aimability performance requirements.

The final rule amends the headlamp horizontal aimability performance requirements to exempt ADB systems from many of the vehicle headlamp aiming device (VHAD) requirements. These requirements are not necessary for ADB systems and exempting ADB systems will lower costs and facilitate ADB deployment in the United States.

B. Interpretation of FMVSS No. 108 as Applied to ADB Systems

Prior to the publication of the NPRM, NHTSA had not directly addressed whether FMVSS No. 108 permits ADB systems. In the NPRM, we tentatively concluded that ADB systems are not currently permitted under the standard because they are part of the required headlamp system, and, as such, would not comply with at least some of the headlamp requirements.

We included this tentative interpretation in the NPRM because some manufacturers had argued that ADB systems should be considered supplemental lighting.

For a more detailed discussion,

see

NPRM, 83 FR 51774-51777.

FMVSS No. 108 specifies, for each class of vehicle, required and optional (if-equipped) lighting elements. The standard sets out various performance requirements for the required and optional lighting elements. The standard also allows vehicles to be equipped with lighting not otherwise regulated as required or optional equipment. This type of lighting equipment is referred to as “supplemental” or auxiliary lighting. Supplemental lighting is permitted if it does not impair the effectiveness of lighting equipment required by the standard. S6.2.1.

In the NPRM we went on to also consider the status of ADB technology if we were, instead, to consider it supplemental equipment. We concluded that this still might not obviate the need for this rulemaking because it would be difficult for NHTSA to verify that the system did not impair the effectiveness of any of the required lighting. That is, whether an ADB system is functioning properly depends on whether it accurately detects oncoming and preceding vehicles in actual operation on the road, and there would be no way to test this under FMVSS No. 108 as the standard had existed prior to this final rule.

Comments

Several commenters (General Motors, LLC [GM], American Honda Motor Co., Inc. [Honda], Global Automakers [Global], Ford Motor Company [Ford], and the Alliance of Automobile Manufacturers [Alliance]) disagreed with NHTSA's proposed interpretation, and contended that ADB systems should be considered supplemental lighting.

Agency Response

The interpretation set out in the NPRM (which concerned the version of the standard in effect prior to this final rule) is now moot because the final rule amends the standard to expressly allow and regulate ADB systems. For the same reason, ADB systems can no longer be considered (as suggested by the commenters) “supplemental” lighting because the rule amends the standard to expressly allow ADB systems, while at the same time subjecting them to a variety of requirements expressly intended for and unique to these systems.

The interpretation set out in the NPRM assumed that the adaptive beam would always be a “lower beam” under the version of the standard predating this final rule because a “lower beam” is defined in the standard as “a beam intended to illuminate the road and its environs . . . when meeting or closely following another vehicle.” This assumed that in the absence of other vehicles ADB systems would provide a full upper beam, and not an adaptive beam. However, some of the commenters pointed out that an adaptive beam (

i.e.,

less than a full upper beam) might also be provided in the absence of other vehicles (for example, in order to minimize glare to the driver from retroreflective signs). As we explain later in this preamble, the final rule allows for this type of beam design.

C. Track Testing Requirements and Procedures

1. Practicability of Proposed Test Scenarios

The NPRM proposed a wide range of track test scenarios, including a large set of potential stimulus vehicles, varying road geometries (curves, straight paths), and varying vehicle speeds.

NHTSA tentatively concluded that the proposed ranges of stimulus vehicles and test scenarios were appropriate to ensure that an ADB system functions robustly

and avoids glaring other drivers in a wide variety of real-world circumstances. The agency explained its concerns about a test procedure permitting an ADB system designed to accommodate only a narrow range of vehicles and explained that the proposed scenarios would require ADB systems to be able to negotiate a variety of real-world conditions. NHTSA tentatively concluded that the proposed testing was practicable but acknowledged that certain scenarios might be challenging for some ADB systems. The agency also explained its decision not to propose some common scenarios. For example, we explained that the proposal did not include testing ADB performance when approaching a vehicle at an intersection oriented perpendicular to the ADB vehicle's direction of travel because existing ADB systems would have a difficult time meeting the performance criteria in such scenarios and the magnitude and effect of glare in this situation would be relatively minimal (because the vehicle illuminated by the ADB system would be stopped or preparing for a stop).

The test matrix specifies ranges for the various test parameters. Other provisions in the final regulatory text also specify ranges of values at which various testing parameters may be set. The larger the range of values, the broader the parameters for which the vehicle much perform. Where a range of values is specified, the vehicle must be able to meet the requirements at all values within the range. In addition, the word “any,” used in connection with a range of values or set of items in the requirements, conditions, and procedures of an FMVSS means generally the totality of the items or values, any one of which may be selected by the agency for testing.

See

49 CFR 571.4, Explanation of Usage.

Comments

The agency received a number of comments on the practicability of the proposed test scenarios. Many of the commenters, including many vehicle and equipment manufacturers and trade associations, agreed with the need for track testing, but most stated that the proposed testing was unnecessarily broad and impracticable. Intertek supported a more rigorous dynamic roadway test than specified in SAE J3069, but stated that the full set of proposed scenarios may not be necessary and estimated testing costs to be two-to-four times higher than testing to SAE J3069. Consumer Reports and IIHS also supported a vehicle-level track test but stated that the proposed track test was too broad. Many industry members (Honda, Global, GM, SAE, Competitive Enterprise Institute (CEI), Toyota, Alliance, Mobileye, OSRAM Sylvania Inc. (OSRAM), the Motor & Equipment Manufacturers Association (MEMA), Infineon Technologies Americas Corp. (Infineon), Valeo Lighting Systems (Valeo), and NAFA Fleet Management Association (NAFA)) supported the use of SAE J3069, which includes a more limited track test, and/or specifically supported a more limited track test than proposed. Commenters made a variety of arguments for why they believed the proposed track test was not practicable.

A number of commenters

stated that the proposed track test was not practicable because of the number and complexity of the proposed scenarios. For example, SAE stated that testing over 34 different maneuvers on various road geometries with multiple variations is excessive and not practicable. IIHS similarly commented that the number of scenarios could be reduced to a more manageable set without sacrificing the tests' ability to identify systems unable to adequately mitigate glare. IIHS estimated that testing every scenario with all four types of stimulus vehicle would require 272 tests, and that testing at different speeds would require even more tests. Toyota estimated that the proposal resulted in 10,000 possible test scenarios.

These were MEMA, IIHS, Toyota, Alliance, SAE, Auto Innovators, Honda, Global, Valeo, Volkswagen, the International Organization of Motor Vehicle Manufacturers (OICA), GM, Ford, and the Transportation Safety Equipment Institute (TSEI).

Several commenters claimed that the proposal would necessitate testing capabilities beyond those available at existing test facilities. The Alliance for Automotive Innovation (Auto Innovators) conducted a series of tests based on the proposed scenarios and commented that it found that the proposed scenarios were unnecessary and beyond the capabilities of many proving grounds. Volkswagen, the Alliance, Valeo, and Auto Innovators commented that the proposed test scenarios necessitated test tracks with characteristics (

e.g.,

specified radii of curvature, road surface conditions, test track length necessary for attaining specified speeds) that were not within the capabilities of existing proving grounds. SAE, Auto Innovators, OICA and the Society of Motor Manufacturers and Traders (SMMT) contended that the proposed track test would necessitate data measurement capabilities beyond those which are currently available at test facilities, with Auto Innovators arguing that the proposal would require up to 476 data elements. Auto Innovators also commented that the amount of time needed for data collection and processing was longer than expected, and it recommended that NHTSA develop software or other compliance tools to expedite data processing. To address these issues, Auto Innovators recommended (among other things) adopting fixed lighting stimuli, limiting the number of eligible stimulus vehicles, and limiting the number and complexity of test scenarios.

A few commenters suggested eliminating redundant scenarios and/or testing only the most stringent scenarios. Auto Innovators suggested that by adopting the most stringent test scenarios at the extremes of the testing range, the intermediate tests could be eliminated. For example, Auto Innovators suggested only specifying straight and small-radius curve scenarios because the small-radius curve was the most stringent test with 46 failures out of 127 valid test runs (36.2% failure rate), while the failure rates for the straight, mid, and large radius test scenarios were 26.6%, 26.7%, and 22.4%, respectively. IIHS stated that while the volume of proposed test scenarios might be justified if each scenario presented substantially different conditions for the ADB system, that is not the case with the proposal; an algorithm based on a camera sensor has limited ability to compute distance and vehicle type solely using another vehicle's headlamps or taillamps. For example, from the camera's perspective, a larger vehicle farther away will look the same as a smaller vehicle at a closer distance. As a result, ADB algorithms will be designed to the boundary cases of the range of scenarios NHTSA finalizes, which should allow the intermediate scenarios to be eliminated.

The Truck and Engine Manufacturers Association (EMA) commented that the NPRM did not consider the significant barriers and expense of the proposal on the heavy-duty market. EMA stated that the heavy-duty market presents unique challenges for ADB development because of the wide variation of potential vehicle configurations due to extensive customization and low volume.

EMA commented that these varied configurations determine the height and angle of the vehicle, and in the case of incomplete vehicles the angle of the chassis may change upon completion of the vehicle by a body-builder. EMA also commented that performing track-level testing on hundreds of vehicle configurations would be cost-prohibitive, and track-testing facilities are not readily accessible to manufacturers. EMA also commented that the NPRM did not include any data specific to heavy-duty vehicles and stated that such testing would be necessary before finalizing the rule. EMA stated it was unable to fully evaluate the proposal due to the immaturity of ADB technology for the heavy-duty market.

EMA also commented about the impact of the driver's eye point and sensor positions in heavy-duty vehicles, but NHTSA was unsure of the meaning of this comment.

Global commented that NHTSA should justify the fact that the proposal was more stringent than the current semiautomatic beam switching device requirements (which are limited to a test of the “camera” device and do not test the overall system).

Agency Response

NHTSA agrees that the proposal included redundant scenarios and that the final rule can more closely follow SAE J3069 without sacrificing the robustness of the test. The final rule specifies stationary test fixtures outfitted with vehicle lamps instead of dynamic stimulus vehicles. The test fixture specifications are similar to those specified in SAE J3069, but differ by specifying original equipment vehicle lamps. Accordingly, the final rule eliminates all scenarios involving a moving stimulus vehicle.

NHTSA also modified the specified road geometries. The final rule retains scenarios with actual curves. However, considering lower beam and ADB system capabilities, NHTSA has narrowed down the curve scenarios by eliminating the short right-curve scenario and truncating the measurement distances for all but the large left curve scenario. NHTSA similarly modified the measurement distance for the preceding scenarios. We believe that the final test scenarios are sufficient to determine whether an ADB system prevents glare to other motorists. The reasons for these modifications are discussed in more detail in Section VIII.C.8, Test Scenarios and Section VIII.O, Regulatory Alternatives.

The agency narrowed down the test scenarios by identifying aspects of performance that an acceptable ADB system should meet and choosing scenarios that would be the most challenging with respect to those aspects of performance. For example, the final rule includes a same-direction left curve scenario in order to test the ability of an ADB system to recognize dim red lamps at wide angles.

However, the agency's testing showed that it was not possible to identify a radius of curvature (

e.g.,

shortest) that would necessarily present a “worst-case” for all aspects of an ADB system. For example, with the oncoming car/truck test fixture outfitted with the Camry headlamps on a left curve, the shorter-radius curve was, in fact, more challenging for the ADB system used for testing as evidenced by the fact that it nearly exceeded the glare limit. See Figure 2.

However, when tested with the preceding motorcycle fixture in a left curve test scenario, the ADB system tested failed the test on a larger-radius curve but passed the test on a smaller-radius curve. See Figure 3. On the larger-radius curve, the system failed to recognize the motorcycle taillamp for the entirety of the test (the detectors are saturated at the end of the test, so it is not possible to interpret the results from 30 m-15 m). This suggests that a variety of test scenarios, including a range of different curves, are needed to test the variety of factors that contribute to a properly-performing ADB system. While in many instances, shorter-radius curves will be a worst-case scenario, the agency does not believe such curves will necessarily represent the worst-case for all ADB systems; complexities in the recognition system can create a far more complex set of test results. The final rule therefore retains curves with a range of radii of curvature.

The agency saw a similar result in its 2015 data.

See

Adaptive Driving Beam Headlighting System Glare Assessment, DOT HS 812 174, August 2015, NHTSA U.S. Department of Transportation, p.168 (Fig. 74). The vehicles tested as part of that research demonstrated a similar performance with respect to curve radius and closing speed. The glare was higher for the moving stimulus vehicle as compared to a stationary one.

ER22FE22.002

ER22FE22.003

NHTSA implemented the finalized test scenarios using readily-available photometric measurement and processing equipment. Accordingly, the agency has concluded that it is within the capabilities of current testing facilities to test to the final requirements.

The agency is not persuaded by EMA's comments regarding heavy-duty vehicles. Because ADB systems are not required, heavy-duty vehicle manufacturers may take time to fully develop ADB technologies for use on these vehicles. Moreover, while the development of ADB systems for heavy-duty vehicles is less mature than for passenger cars, the agency does not believe these challenges to be insurmountable, or that meeting the requirements of this final rule is impracticable. There are a few reasons for this. First, the ability of the ADB system to dynamically track other vehicles is independent of the specific characteristics of the ADB-equipped vehicle, so the fact that the ADB system would be on a heavy-vehicle would not be consequential. Second, the test procedures specify that NHTSA will aim the headlamps on the test vehicle according to the manufacturer's instructions, which provides manufacturers with a means to mitigate the effects of chassis-specific features that might affect system performance by establishing chassis-specific aim specifications. Third, the final rule's extensive modifications to the proposed track test, resulting in a streamlined set of test scenarios, should also help address concerns about heavy-vehicle testing.

We also note that NHTSA was unable to perform testing on heavy-duty vehicles because it was not aware of any such vehicles that are ADB-equipped. In any case, for the reasons given above, we do not believe that it is necessary to test heavy-duty vehicles prior to adopting this rule.

Finally, while the requirements and test procedures in the final rule are an increase in stringency from the longstanding requirements for semiautomatic beam switching devices, this final rule is appropriate because ADB systems are capable of providing an enhanced beam that is brighter than the lower beam, which presents an increased risk for glare if the system is not designed appropriately.

2. Test Fixtures vs. Stimulus Vehicles

NHTSA identified two main alternatives to the proposed broad range of eligible stimulus vehicles that would be used to elicit an ADB system response. First, the agency considered specifying a small set of specifically-identified stimulus vehicles, but tentatively decided that a broad range of potential stimulus vehicles was necessary to ensure that an ADB system can recognize multiple headlamp/taillamp configurations on vehicles of different sizes and shapes.

Second, NHTSA considered specifying test fixtures, including those specified in SAE J3069.

The NPRM noted SAE's rationale that fixtures represent a worst-case scenario because some cameras use movement to identify objects as vehicles. It also noted SAE's explanation that the fixture lamps would represent a “reasonable worst case for intensity and location and should promote test repeatability.”

NHTSA also noted that test fixtures could be easier to use than actual vehicles.

See

NPRM at p. 51782-51783.

SAE J3069, p. 3.

However, the proposal identified several potential concerns with test fixtures. The major concern was the lack of realism, so that fixtures might not indicate whether the ADB system would recognize actual vehicles and instead could permit ADB systems to be tuned to detect fixtures. Another concern related to possible difficulties in tuning out non-vehicle objects. Also of concern was the possibility that the fixture characteristics might not represent a worst case.

The NPRM therefore proposed a large set of eligible stimulus vehicles. The agency tentatively concluded that it would be practicable for manufacturers to design ADB systems to recognize and

shade any vehicle satisfying the proposed selection criteria. NHTSA noted that the lighting configurations an ADB system would have to recognize would not be unreasonably large, as front and rear lighting designs are limited by the requirements of FMVSS No. 108 and the realities of vehicle design. NHTSA also reasoned that there is a limited, and not exceptionally large, number of makes and models of new vehicles offered for sale in the United States every year (approximately 420), and that the set of eligible stimulus vehicles would be further limited by the proposed vehicle height constraint.

Comments

Vehicle and equipment manufacturers opposed the use of stimulus vehicles and commented that NHTSA should instead follow SAE J3069 and use test fixtures. These commenters identified a variety of specific concerns with stimulus vehicles.

Several commenters (Mobileye, EMA, Volkswagen, SMMT, Ford, Toyota, SAE, the Alliance, Global, and Honda) contended that the proposed stimulus vehicle specifications would result in an impracticably large set of potential vehicles. For example, SAE and the Alliance commented that the NPRM specified an unmanageable and exceptionally large number of potential stimulus vehicles, exacerbated by the fact that many vehicles have multiple headlamp and/or taillamp trim levels, and that the proposal does not account for motorcycles or heavy-duty vehicles. They estimated that this could result in a set of up to 1,000 eligible stimulus vehicles. The Alliance also contended that it would be impossible for a manufacturer to choose a worst-case scenario and guarantee that testing with the other thousands of vehicle choices would exhibit reproducible results for the multitude of requirements. MEMA, Volkswagen, and the Alliance commented that the proposal would cause manufacturers to incur costs from repeated testing as the stimulus vehicles need to be refreshed every year. Volkswagen also commented that obtaining stimulus vehicles would be especially burdensome for foreign original equipment manufacturers (OEMs) and test facilities.

Mobileye, SAE, Honda, and Ford commented that an FMVSS requiring a manufacturer certification to account for the various configurations and performance of thousands of vehicles in the market would be unreasonable and unprecedented, as opposed to other FMVSS which simulate real-world conditions with standardized test apparatus. As an example, SAE, Ford, and Honda pointed to FMVSS No. 208, which uses a fixed barrier to simulate a stimulus vehicle crashing head on into the test vehicle within one specified range of speeds and does not require selecting actual vehicles from a large population available in the market to conduct this testing. Honda also pointed to FMVSS No. 214 (side impact) and FMVSS No. 301 (rear impact), and various New Car Assessment Program (NCAP) test procedures that standardize the device used to assess the crashworthiness of the test vehicle. SAE and Honda contended that this approach allows the test to be practicable and objective, and SAE suggested such an approach would be sufficiently realistic because, as the NPRM noted, the lighting configurations an ADB system would have to recognize are limited by the requirements of FMVSS No. 108 and realities of vehicle design.

Commenters also raised concerns related to vehicle production cycles. SAE and Ford commented that the cycle plans of any given vehicle design can last many years, with those designs solidified many months prior to production, making it impossible for manufacturers to account for other manufacturers' vehicles in any manageable timeframe. A manufacturer would not be aware of which vehicles may pose compliance challenges for its ADB system prior to these vehicles being sold to the public, especially considering the extremely conservative and challenging requirements associated with the NPRM. Honda made similar comments.

Mobileye commented that the proposal would lead OEMs to over-tune the ADB system in order to ensure compliance, resulting in non-optimal and overly sensitive system behavior and diminished safety benefits.

Several commenters (Global, Mobileye, Valeo, the Alliance, MEMA, and Volkswagen) raised concerns regarding the repeatability and/or reproducibility of compliance test results. SAE, the Alliance, SMMT, and Honda commented that the proposal was not objective.

A few commenters did support using stimulus vehicles. Consumer Reports supported a broad range of stimulus vehicles as reasonable to adequately ensure ADB systems detect, identify, and shade vehicles of different size, shape, and lighting configurations; however, it also urged that testing be practical and efficient. Intertek commented that a simple static test fixture may not be sufficient, and that using any make or model within defined physical constraints is preferable to adding an appendix with a list of eligible test vehicles. AAA commented that no certified motor vehicle should be excluded from use as a stimulus vehicle, and that the proposed limitation to the past five model years together with the vehicle height constraints were practical and acceptable.

Several commenters, while not supporting the use of actual vehicles, commented that if NHTSA were to use actual vehicles, it should further limit the set of eligible stimulus vehicles. SL Corporation (SL) commented that detailed criteria for stimulus vehicles (such as light source, luminous intensity of the stimulus vehicle's headlamp and rear lamp), specified by vehicle type, is needed. Global commented about a need for consistency in any testing, further arguing that the rule could bookend the vehicle population's performance (

i.e.,

lowest/highest, narrowest/widest) to constrain the massive number of stimulus vehicles. Toyota suggested that NHTSA limit the number of stimulus vehicles to a practical and manageable list by only using the top three U.S. selling vehicle models for each of the vehicle types identified in Table XXI of the NPRM in the fifth model year prior to the model year of the certified vehicle. Honda stated that if NHTSA does not adopt test fixtures, it should test with a single stimulus vehicle chosen by the manufacturer. Valeo suggested specifying a standard stimulus vehicle. Mobileye suggested modifying SAE J3069 by defining the use of a standardized dummy stimulus vehicle with lamps representative of those approved by FMVSS No. 108 instead of the static fixtures specified in SAE J3069. Mobileye also recommended complementing the (modified) SAE test with a requirement for an additional test drive by a test engineer to ensure stable detection and reaction to vehicles of different makes and models in additional real-world scenarios not specified in the track test.

Agency Response

After evaluating the comments and considering the requirements of the Safety Act and the National Technology Transfer and Advancement Act (NTTAA),

NHTSA has decided to specify test fixtures instead of stimulus vehicles. The NTTAA directs agencies to use voluntary consensus standards unless, among other things, doing so would be inconsistent with applicable

law. We believe the test fixtures specified in the final rule are consonant with both the Safety Act and the NTTAA.

In particular, we believe the test fixtures both meet the need for safety and better align with SAE J3069 and other countries' standards.

National Technology Transfer and Advancement Act of 1995, Public Law 104-113, 110 Stat. 775 (1996).

See

Section X, Rulemaking Analyses and Notices.

We also note that the final rule does not adopt Mobileye's suggestion to supplement the track test with an evaluative drive by a test engineer, because such a requirement would not satisfy the Safety Act requirement of objectivity.

Most importantly, we concluded that the test fixtures specified in the final rule meet the need for safety. There are two main reasons for this. First, in this case the need for safety requires us to balance visibility and glare prevention. As some commenters pointed out, a too-demanding track test to evaluate glare, including a large set of eligible stimulus vehicles, could lead manufacturers to tune the system to provide sub-optimal forward illumination. Second, we concluded that using real vehicles would generally not challenge ADB systems any more robustly than properly-specified fixtures. In the NPRM we expressed the concern that insufficiently realistic test fixtures could lead to ADB systems with performance tuned to the fixtures, not to real vehicles, resulting in a test that does not sufficiently replicate real-world performance. To address this concern, NHTSA developed test fixtures fitted with original manufacturer replacement equipment vehicle headlamps and taillamps, instead of the lamps specified in SAE J3069 that are intended to simulate vehicle lighting. (See Section VIII.C.6 for a discussion of the final fixture specifications.) NHTSA then tested whether an ADB system performed differently with these fixtures than with an actual vehicle. As explained below, this testing showed that the ADB system detected and responded to the finalized test fixtures in generally the same way it did to an actual vehicle.

NHTSA's recent research compared ADB performance when tested with the finalized stimulus fixtures versus a stationary stimulus (

i.e.,

actual) vehicle. For the most part, differences in performance were not observed. For example, in straight oncoming and preceding test scenarios, the ADB system recognized both the stimulus vehicle and test fixture before either stimulus entered the measurement range. See Figures 4 and 5.

ER22FE22.004

ER22FE22.005

One exception to this was observed for the smallest-radius left curve (oncoming) at the highest speed. In this case, the ADB system performed better (recognized and adjusted sooner) when exposed to the test fixture. For the fixture, the test vehicle adjusted its light output at around 44 m and did not exceed the glare limits. For the real vehicle, it reacted at 39 m, resulting in a glare exceedance. This suggests that this ADB system likely relies on light source detection rather than using supplemental systems such as radar or LIDAR to detect a vehicle structure. Although we did not systematically test this hypothesis, we suspect that the performance differences observed in this case are caused by small differences in headlamp mounting heights between the fixture and the real vehicle. See Figure 6. The agency did not observe any situations in which the full vehicle was recognized, but the test fixture was not.

ER22FE22.006

The test fixtures specified in the final rule more closely align with SAE J3069 and better harmonize with other countries' standards than the proposed broad range of eligible stimulus vehicles. This should help facilitate deployment of ADB systems in the United States because manufacturers are already familiar with SAE J3069 and because it harmonizes with the Canadian regulations, which permit ADB systems designed to meet either ECE R123 or SAE J3069. This approach also results in a more manageable set of test scenarios and stimulus vehicles to which manufacturers must certify,

which will also result in a less complex and costly test. Test fixtures will reduce the test burden by establishing a consistent stimulus for testing, reducing the cost of acquiring and maintaining the test stimulus, reducing the test time, and more closely harmonizing with SAE J3069. NHTSA's testing showed that fixtures simplified the coordination of each test run. A single test driver was required to drive the test vehicle as opposed to two drivers required for tests involving dynamic stimulus vehicles. Additionally, no start and stop coordination was needed between the two drivers. The use of fixtures also facilitates set-up for different scenarios.

Specific to this rulemaking, NHTSA has concluded that using test fixtures better balances the safety needs of visibility and glare prevention, and is more practicable and appropriate, than using a broad range of potential stimulus vehicles. We are not implying that a large set of potential stimulus vehicles is necessarily impracticable for an FMVSS. We also note that we do not agree with the commenters who claimed that the proposal raised issues with respect to objectivity, repeatability, or reproducibility.

NHTSA developed a single test fixture that was capable of mounting both the motorcycle and the car/truck vehicle lamps; the various lamps could be switched between test runs of different scenarios.

3. Justification for Testing on Curves and General Approach for Scenario Selection

In addition to testing ADB performance in a straight-path scenario, the NPRM proposed testing ADB systems on curved-path scenarios (both left and right curves) with a variety of radii of curvature. The agency proposed testing on a “small” curve with radii of curvature from 98 m-116 m (320-380 ft); a “medium” curve with radii of curvature of 223 m-241 m (730-790 ft); and a large curve, 335 m-396 m (1100-1300 ft). The NPRM explained that the small curve was chosen because it corresponded (approximately) to the shortest radii of curvature appropriate for a vehicle traveling 25-35 mph, approximately the minimum speed for which we proposed to allow ADB activation. The medium curve corresponded to the shortest radii of curvature appropriate for the higher ADB minimum activation speeds of some of the ADB-equipped vehicles NHTSA tested. Finally, the large curve was intended to correspond to a curve appropriate for vehicles traveling at higher speeds, to test ADB performance on curves at higher speeds. Values for speed and radius of curvature were selected to be consistent with the simplified curve formula.

This is a standard formula used in road design that specifies the relationship between vehicle speed and the radius of curvature.

See infra

n.142 and accompanying text.

The NPRM recognized that curves might present engineering challenges for ADB systems. For example, on a curve an oncoming vehicle enters the ADB system's field of view (FOV) from the edge; in a tight curve, an oncoming vehicle will enter the field of view at a closer distance than in a larger-radius curve. Performing adequately on large-radius curves at relatively high speeds consequently presents a slightly different engineering challenge than performance on tight curves at lower speeds.

Comments

Consumer Reports supported testing using curved path scenarios of various curvatures. Intertek supported a more rigorous dynamic roadway test than specified in SAE J3069 (which specifies straight test drive paths) because the SAE J3069 approach may not be sufficient to validate the performance of the ADB sensor over the range of situations that it will normally encounter.

On the other hand, several commenters opposed or raised issues with testing on actual curves. SAE commented that NHTSA should follow SAE J3069 and simulate curves using a straight path and varying the placement of the test fixtures. SAE contended that curves are not necessary because continuous tracking of the angular location of the test fixture in straight scenarios is required, and that removing curves would greatly reduce the testing burden. SAE noted that it considered including curves in SAE J3069 but concluded that attempting to capture hundreds of potential road geometries would make the test excessively burdensome because ADB systems would function similarly over many of these geometries and including them all would provide no added value. SAE further determined that testing on a straight path with one lane to the right and more than one lane to the left of the ADB-equipped vehicle would capture the conditions necessary to determine whether an ADB system functions appropriately and ensures an adequate response to a wide variety of road geometries, while allowing the test method to be simple enough to be objective and repeatable. For example, SAE J3069 requires that in a straight-line encounter, an ADB system must continuously track the angular location of an opposing vehicle fixture as that angular position becomes increasingly further from the center of the camera's field of view with decreasing distance to the opposing vehicle. SAE commented that such an approach allows evaluation of vehicles encountered on curves to be captured without using actual curves.

SAE, ALNA, Toyota, and the Alliance stated that the proposal would require ADB systems to produce less glare than current FMVSS No. 108-compliant lower beams, and that this issue was particularly acute on curves. They argued that the proposed approach would reduce lower beam visibility and negatively impact safety. SAE provided analyses and graphs based on IIHS data on lower beam performance on different road geometries, from straight roads to left and right curves of various radii. Stanley and Intertek also asserted that the final rule should account for the fact that current lower beams would not comply with the glare limits on right curves.

The commenters' data and arguments on these points are discussed in more detail in the sections below discussing each of the test scenarios in the final rule.

Agency Response

The final rule does not adopt some commenters' recommendation to forgo actual curved-path scenarios, but it does reduce the measurement distances in many of the test scenarios for which curves are specified.

The agency is not persuaded that the SAE J3069 approach of simulating curves by varying fixture placement relative to a test vehicle's straight path adequately replicates curves. Two features of the SAE test are intended to replicate what the system would encounter in an actual curve. First, the fixtures are placed to the side of the test vehicle's path. Second, the sudden appearance scenario is intended to roughly replicate a curve in that the fixture's stimulus lamps become visible at a close distance, which would happen on a relatively tight curve. (The sudden appearance scenario is also intended to exercise the ability of the ADB system to react to real world situations such as another road user turning on their lights, turning onto the road, or cresting a hill at distances as close as 100 m.) This approach, however, does not accurately replicate real curves in at least two respects.

One is the trajectory of the fixture as it is tracked by the ADB system (see Figure 7). An approaching vehicle on an actual curve enters the ADB system's field of view from the edge, at a relatively far distance; moves towards the center of the field of view as the distance to the fixture closes; and then moves out towards the edge of the field of view at a close distance. The trajectory is different, however, when attempting to replicate a curve using a straight path and fixtures placed out to the side. There, the fixture is first detected by the ADB system near the center of the camera's field of view at a far distance, and then moves out towards the edge of the field of view at closer distances.

For example, on an actual left curve with a radius of 230 m, the fixture enters the FOV at the edge (25L) at a relatively far distance (191 m) and moves towards the center of the FOV until around 35 m at which point it moves out towards the edge of the FOV again (see Figure 7). In comparison, in the SAE test run, at 155 meters (the start of the SAE test), Fixture 1 is near the center of the FOV at approximately 2.5 degrees left, and as the test vehicle approaches the fixture the fixture moves out to the edge of the field of view.

As another example, this time on a right curve with a radius of 230 m, the fixture enters the FOV at the right edge of the field of view (25R) at about 205 m and moves towards and then across the center of the FOV. In comparison, in the SAE test, at 155 meters (the start of the SAE test), Fixture 3 is near the center of the FOV (at about 3 degrees right), and as the test vehicle approaches the fixture the fixture trajectory moves out to the right edge of the field of view. The SAE test evaluates rather large angles to the right of the beam pattern, almost entirely to the right of where the NHTSA test method examines the beam pattern performance. The agency believes this to be unusual in reality, particularly for oncoming encounters.

Because the SAE test does not accurately replicate the fixture trajectory, it does not test how the system will need to actually function. For example, one way to “optimize” optical recognition is to focus on where an object is most likely to appear. The speed and accuracy of image recognition software can be increased without increasing computing power if systems are trained to look in smaller portions of an image for key elements, as opposed to looking at the entire image continuously. Including test scenarios with actual curves will discourage manufacturers from taking “shortcuts” and designing ADB systems that do not react until the stimulus vehicle enters narrow angles within the camera's FOV.

BILLING CODE 4910-59-P

ER22FE22.007

Second, the SAE approach does not accurately replicate real curves with respect to the speed at which the fixture traces its trajectory. On an actual curve, the fixture travels horizontally across the FOV relatively quickly at longer distances than on a simulated curve. For instance, a left curve requires the headlamp to start shading on the left side of the pattern, quickly move to the right; briefly hold the shade near the middle; and very quickly move the shade back to the far left. A simulated curve, on the other hand, simply necessitates that the system starts shading the middle of the pattern; hold nearly that same angle; and then quickly move the shade either left or right at closer distances. Including actual curved-path scenarios will discourage manufacturers from very accurately following the straight path pattern but less accurately following the paths required for real-world curves; it should therefore result in better real-world performance than would the SAE J3069 fixture placements.

NHTSA's recent testing confirmed that the SAE scenarios do not accurately model how an ADB system will perform on an actual curve. For example, the agency tested ADB system performance on an 85 m left curve as well as the most closely analogous SAE scenario, with the fixture place in Fixture Position 1. (Fixture Position 1 is the closest analogue to this scenario because it is the leftmost fixture position in the SAE test.) See Figure 8. On the actual curve, the system did not recognize and adjust to the fixture until 45 m. On the most closely analogous SAE scenario (Fixture Position 1), the system was able to continuously track the fixture from 150 m away. Even when the agency repeated the same SAE scenario at a much higher speed of 61 mph, the SAE test did not challenge the system's image recognition in an observable way. This shows that an ADB system's initial image recognition capability is not challenged by the SAE test as it is in a more realistic curve test, meaning that NHTSA is less confident that the SAE test would result in an equivalent level of safety as the actual-curve test that NHTSA is finalizing. The practical implications of this is that glare will not be sufficiently controlled by the SAE test compared to the actual-curve test adopted in this final rule.

ER22FE22.008

As another example, SAE J3069 does include a sudden appearance test (using the oncoming and preceding motorcycle fixtures) in which the fixture lamps are activated when the test vehicle is between 155 m and 100 m from the fixture. The agency found, however, that this also does not realistically simulate a curve. See Figure 9. On an 85 m left curve at 26 mph, the ADB system recognized the final rule oncoming motorcycle fixture at 20 m. On the SAE sudden appearance scenario, in contrast, the ADB system performed better, activating a shaded area at 70 m. Additional comparative data from the final rule scenarios and the SAE test scenarios are presented and discussed in Section VIII.C.8, Test Scenarios.

ER22FE22.009

BILLING CODE 4910-59-C

NHTSA disagrees with SAE's comment to the extent that it suggests that a final rule incorporating actual curves might not be objective or repeatable. The final rule sets out a rational test procedure that yields a clear answer based upon readings obtained from measuring instruments and is capable of producing identical results when test conditions are exactly duplicated.

The final rule specifies the specific scenarios NHTSA may test, including ranges and values for key

testing parameters (

e.g.,

differing radii of curvature), and specific numeric limits for the maximum allowable illuminance at certain distances; there is thus no ambiguity with respect to the parameter values NHTSA may select in compliance testing. Moreover, NHTSA has conducted a repeatability analysis and has concluded that the finalized test scenarios and procedures are repeatable (see Section VIII.C.11, Repeatability).

See, e.g., Chrysler Corp.

Dept. of Transp.,

472 F.2d 659, 676 (6th Cir. 1972).

NHTSA did, however, agree that some of the proposed curve scenarios were too stringent. With respect to oncoming glare scenarios, the final rule eliminates the short right curve scenario and reduces the distances at which glare on the medium and large right curves and the short and medium left curves is evaluated. With respect to preceding glare scenarios, the final rule includes a straight-path scenario and a medium left curve scenario. The specifications for the radii of curvature have also been slightly modified. These modifications and other choices are explained in more detail later in the preamble.

In general, NHTSA selected the final scenarios based on three criteria:

The scenario represents commonly-encountered roadway geometries and vehicle interactions.

To ensure that ADB systems operate safely, the final scenarios should include at least the most common road geometries and vehicle interactions. Because the adaptive driving beam is intended for distance illumination at speeds at which the lower beam does not provide adequate illumination—typically above 20 mph—these geometries and interactions should be those common at these speeds.

See

NPRM, pp. 51787-51788.

A compliant lower beam could pass the scenario.

We also generally chose scenarios such that a compliant lower beam would be able to pass the scenario. There were several reasons for this. First, this (in conjunction with the requirement that areas of reduced intensity meet the corresponding lower beam laboratory photometric requirements) ensures that an area of reduced intensity, up to and including a full lower beam, will meet the same level of safety (with respect to both visibility and glare prevention) as current lower beams certified to FMVSS No. 108. Second, this is consistent with the concept for the proposal: Extending the current laboratory-based lower beam photometric requirements (specifically, the photometric maxima regulating oncoming and preceding glare) for use in a vehicle-level test to evaluate the ability of an ADB system to minimize glare (both oncoming and preceding).

Because the track test was intended as an extension of the current laboratory photometric requirements, the track test requirements should (generally) be such that a lower beam (or area of reduced intensity) that complies with the current laboratory photometric requirements will also comply with the track test requirements.

See

NPRM, pp. 51770, 51773.

The scenario is generally within the capabilities of robustly-designed internationally-available ADB systems.

As noted above, the field of view for current ADB systems is typically 25 degrees to the left and right of the camera, and, as explained below,

ADB adaptation time—the time it takes an ADB system to recognize a stimulus (once the stimulus is within the camera's field of view) and dim the beam to a level that falls within the applicable glare limit—is generally about 1 second. Therefore, NHTSA generally chose scenarios such that it would be possible for an ADB system with such field of view and response capabilities to pass the scenario. This is not to say that all current ADB systems would necessarily be able to pass all the final scenarios without any modifications. However, the agency intended to select scenarios that were generally within the reach of current technology (perhaps necessitating some additional improvements, adjustments, or optimizations, depending on the ADB technology), to facilitate timely deployment of ADB systems. NHTSA also recognized that these systems have been in use in foreign markets for several years with few, if any, apparent safety issues.

We discuss and apply these criteria in more detail in Section VIII.C.8, Test Scenarios.

See

Section VIII.C.5, ADB Adaptation Time.

The fact that the final rule does not include all the proposed scenarios does not mean that NHTSA has concluded that only a relatively small set of narrowly circumscribed scenarios is permissible in an FMVSS. In this case, NHTSA has concluded that adopting a smaller set of test scenarios appropriately addresses both the need for safety (including facilitating the timely deployment of ADB systems) and practicability. This also does not imply that FMVSS requirements must be tailored to the capabilities of currently existing systems.

See, e.g., Chrysler Corp.

Dept. of Transp.,

472 F.2d 659, 673 (6th Cir. 1972) (“[T]he Agency is empowered to issue safety standards which require improvements in existing technology or which require the development of new technology, and it is not limited to issuing standards based solely on devices already fully developed.”).

4. Maximum Illuminance Criteria (Glare Limits)

The NPRM included a set of photometric maxima to evaluate an ADB system's ability to minimize glare in the track test (glare limits). Because the current photometric test points from which the proposed glare limits were derived are maxima, the agency proposed applying the derived glare limits as maxima, so that any measured exceedance of an applicable glare limit (except for momentary spikes) would be used to determine compliance. The NPRM also extended the standard's “design to conform” language to the proposed requirements, including the glare limits.

The NPRM also summarized the basis for the glare limits (the full explanation for the derivation is given in the Feasibility Study).

As we explained in the NPRM, the proposal extended the standard's longstanding “design to conform” language to the proposed requirements because the concept of the rulemaking was to extend the current headlamp requirements to ADB systems. We therefore considered the continued appropriateness of “design to conform” to be outside the scope of this rulemaking. However, this extension in no way limits NHTSA's ability to revisit the issue of design to conform in the future. Furthermore, if NHTSA were to reconsider the design to conform language, it might not come to the same conclusion it did when it originally adopted that language. As we explained in the NPRM, NHTSA adopted the “design to conform” language when the standard was introduced in 1967 because it accepted industry's contemporaneous representation that vehicle lamps could not be manufactured to meet every single test point without a substantial cost penalty unjustified by safety. We further explained that, because lighting equipment design, technology, and manufacturing have evolved and advanced since the late 1960's, NHTSA might not come to the same conclusion were it to revisit this issue.

The NPRM explained that the proposed glare limits deviate from SAE J3069 in a few respects. First, two of the glare limits differ slightly. At 60 m, SAE J3069 uses glare limits of 0.7 lux (oncoming) and 8.9 lux (preceding) compared to the proposed 0.6 lux and 4.0 lux. Second, SAE J3069 applies to a narrower range of distances (30 m-155 m) than the proposed glare limits (15 m-220 m). Third, SAE J3069 applies the glare limits only at the endpoints of the measurement ranges (

i.e.,

155 m, 120 m, 60 m, and 30 m), while the NPRM applied the glare limits throughout the entire measurement range. The proposal explained the reasons for these deviations from SAE J3069.

Comments

A few commenters (AAA, Consumer Reports, and Zoox) supported the glare limits as proposed. Intertek agreed that the baseline glare limit requirements should extend to the full distance ranges rather than only at the four individual distances specified in SAE J3069. Several commenters, however, contended that the glare limits were too stringent and suggested a variety of modifications.

SAE, Global, Ford, Toyota, the Alliance, and Auto Innovators commented that the proposed glare limits were conservative and that using absolute measurements of discomfort glare (the aspect of glare that is painful or annoying, as opposed to the aspect of glare that limits the ability to see other objects) is unreasonable and not practicable. They recommended the final rule include reasonable allowances for an ADB system to momentarily exceed the glare limits, especially given the large number of proposed test scenarios. They also stated that the proposed glare limits are well below the illuminance provided by contemporary lower beams, including Insurance Institute for Highway Safety (IIHS) top-rated lower beams for MY 2017 vehicles, especially on curves. As noted earlier, SAE provided analyses and graphs based on IIHS data on lower beam performance on different road geometries, from straight roads to left and right curves of various radii.

Auto Innovators also supplied an apparently somewhat similar analysis of IIHS data (on pp. 12-13 of its comment). However, the comment did not identify the geometry of the road (the orientation of the headlamps to the photometer) for the measurements, so the agency is unable to evaluate this submission. In any case, NHTSA addresses this issue using the IIHS data submitted by SAE and the agency's own testing of lower beams to the scenarios included in the final rule.

For those reasons, SAE, the Alliance, and Toyota argued that NHTSA should evaluate the ratio of the ADB to lower beam illuminance. SAE noted that this procedure is specified in SAE J3069, which requires the measured illuminance to be no more than 25% above the measured lower beam illuminance. SAE further stated that NHTSA's 2015 ADB Test Report used a similar procedure, and that an UMTRI report found that 25% was an acceptable maximum limit above the lower beam.

Toyota commented that following SAE J3069 in this respect would facilitate ADB deployment across a wider range of vehicles.

Auto Innovators also argued for a similar 25% allowance (discussed below).

DOT HS 808 209, Sept. 1994.

SAE and other commenters also argued that comparing the ratio of the illuminance from the adaptive beam to the lower beam would also compensate for unaccounted for test variability such as dips and bumps in the road. This is discussed below in Section VIII.C.10.d, Allowance for Momentary Glare Exceedances.

A few commenters expressed interest in the final rule accounting for glare dosage. Toyota commented that there is no clear evidence that exceeding the maximum illuminance for longer than 0.1 second leads to a safety hazard any greater than what occurs with existing headlighting systems on U.S. roads today. Mobileye similarly commented that a distinction needs to be introduced between glaring that may cause discomfort to other drivers and glaring which may pose a safety risk. It asserted that, while the NPRM assumes that any glare exceedances for more than 0.1 seconds are not acceptable, drivers commonly use intentional, limited glaring as a signaling mechanism to other drivers. Accordingly, Mobileye suggested allowing glare exceedances longer than 0.1 seconds. AAA commented that the final rule should not permit glare exceedances lasting longer than 1 second because its research showed that glare from an oncoming vehicle lasting approximately 1 second was rated as highly distracting. Intertek believed that proposed 0.1 second allowance would account for the majority of the issues related to glare dosage, exposure, or perceptibility because any longer exceedance is detectable by the human eye. Auto Innovators also asserted that the final rule should account for glare dosage. (This is discussed further below.)

NHTSA received a few comments about the proposed measurement distances. Intertek commented that regulating glare for distances extending out to 220 m is unnecessary because the angular size and position of oncoming headlamps at distances greater than 155 m mitigate any harmful effects of glare. Intertek commented that testing out to 220 m creates additional complexity and testing costs. In contrast, AAA suggested regulating glare beyond 220 m. They noted that European specifications require camera recognition and reaction at distances of 400 meters (1,312 feet), and that intensity limits could be increased from the current maximum of 150,000 cd to the European maximum of 430,000 cd if ADB systems are effective at this distance. SAE commented that the proposed requirements for preceding glare are too stringent, given the detection distance (120 m vs. 100 for the ECE) and the minimum photometric requirements for rear lamps (2 cd vs. 4 cd for the ECE).

Valeo commented that the proposed maximum illuminance requirements would result in wildly varying light output, especially compared to the current ECE requirements, which result in a much more constant and consistent light intensity. Valeo also suggested that the final rule clarify that the requirements apply to the entire ADB system (both left-hand and right-hand headlamps).

Intertek suggested measuring luminance

from the ADB system headlamps rather than illuminance at the test fixture would provide several benefits, including: The data collected from the test would have a record which is very closely matched, and can be perceived and analyzed in much the same way as what an actual driver of the stimulus vehicle would have experienced; the recorded data can be viewed as a map of luminous intensity (candela) emitted from the test vehicle, which would be directly comparable to the existing photometry requirements, and can be plotted as a function of time or approach distance; over time, if this data is collected carefully and attention is paid to those scenarios in which the driver of the stimulus vehicle feels glared, a better quantitative baseline for and understanding of glare can be established.

“Luminance” refers to the luminous intensity produced by a light source in a particular direction per solid angle, while, as noted earlier, “illuminance” refers to the amount of light falling on a surface. The unit of measurement for luminance is candela, while the unit of measurement for illuminance is lux. A measure of luminous intensity in candela can be converted to a lux equivalent (and vice versa), given a specified distance.

Auto Innovators stated that NHTSA should adopt a modified version of the IIHS right-curve glare exposure criteria for all oncoming scenarios.

See Table 5. Auto Innovators contended that this would be appropriate because the IIHS glare limits are intended to provide consumers with a relative assessment of headlamp performance and it is possible for a vehicle to drastically exceed the glare criteria in the IIHS test and still comply with FMVSS No. 108; the IIHS protocol allows exceedances in the form of cumulative exposures as opposed to hard pass/fail limit at a single point in time, resulting in a series of demerits (based on the percentage over the limit) for which it is possible for a vehicle to achieve a “Good” rating while still offering small amounts of glare. Auto Innovators recommended adopting a similar method for establishing an allowable time exceedance for each test range.

Insurance Institute for Highway Safety.

Headlight Test and Rating Protocol, Version III

(July 2018);

Rationale and Supporting Work for Headlight Test and Rating Protocol.

(August 2015).

Table 5—Auto Innovators' Modified Maximum Illuminance Criteria Based on IIHS Protocol

Distance

(m)

Illuminance

limit

(lx)

30 to 59.9

60 to 119.9

3.4

120 to 220

Auto Innovators gave a few different arguments for adopting its proposed glare limits. First, it claimed that the IIHS glare limits better reflect modern headlighting systems. It noted that the proposed glare limits are based, in part, on headlamps typical of the 1997 model year, whereas the IIHS protocol is based on contemporary headlighting systems. Next, Auto Innovators contended that the IIHS protocol accounts for research indicating that the harmful effects of glare depend on both peak illuminance and overall dosage of glare exposure. Finally, Auto Innovators contended that the IIHS methodology accounts for glare effects due to incidence angle whereas the Feasibility Study does not. Auto Innovators recommended eliminating the 15-29.9 m measurement range (for both oncoming and preceding scenarios) because its test data showed not only that the least amount of failures occurred in this interval but that the exceedance durations for all failures in this range were 1.0 second or less.

Auto Innovators also argues that glare exceedances at these short distances may be caused by swiveling of the headlamps. While this only applies to swiveling beam ADB systems, Auto Innovators believes that any safety standard should remain technology neutral.

In addition to recommending NHTSA adopt its suggested glare limits, Auto Innovators recommended that the final rule require passage of a percentage of averaged individual illuminance readings to achieve compliance instead of looking to the maximum recorded illuminance in each measurement range. Specifically, Auto Innovators appeared to suggest that NHTSA perform three test runs for each scenario and average the maximum illuminance in each measurement range recorded for each scenario. Then, it asks that NHTSA allow up to 15% of the averaged illuminance readings to exceed its recommended glare limits by up to 25%. Auto Innovators cited the same UMTRI and NHTSA reports referenced earlier, as well as three inconsequentiality petition grants as the basis for the 25% allowance.

Auto Innovators commented that the 15% allowance comes from the turn signal test requirements in S14.9.3 of FMVSS No. 108. It contended that this amount of performance variation is consistent with the challenges of outdoor dynamic testing where little previous experience exists, especially compared to the highly-controlled laboratory photometric testing that has previously been used. Auto Innovators commented that it would be difficult not to attribute failures of illuminance readings to variances that could appear in the novel and unique aspects of the test procedure, rather than to quality control issues, particularly where the time and complexity of the testing preclude conducting it on multiple ADB-equipped vehicles. It also asserted that this approach is consistent with the standard's design to conform language. Mobileye similarly suggested specifying a pass/fail ratio for the measured illuminance values in each specified measurement interval.

85 FR 39678 (July 1, 2020) (grant of petition for inconsequential noncompliance for side marker lamp below photometric minima); 85 FR 39679 (July 1, 2020) (grant of petition for inconsequential noncompliance for rear reflectors below minima); 55 FR 37601 (Sept. 12, 1990) (grant of petition for inconsequential noncompliance for taillamp exceeding maxima).

Agency response

NHTSA agrees with the commenters that the proposed glare limits were overly stringent at some geometries and measurement distances in that a current, FMVSS No. 108-compliant lower beam would not have complied with some of these requirements. The agency has therefore modified the proposal by deleting the short right curve scenario and modifying measurement distances for other specified radii of curvature. NHTSA believes that these modifications reasonably ensure that a lower beam that complies with the current FMVSS No. 108 photometry requirements would be within the glare limits as applied in the specified measurement ranges in each of the final scenarios. This is discussed in further detail in Section VIII.C.8, Test Scenarios.

100

NHTSA anticipates that ADB systems could provide better glare protection than current lower beams if dynamic vertical aim is incorporated into the systems. Current lower beams will produce glare on hills and undulating roads. Because of the nature

This text is long and has been trimmed here. Open the source document for the complete record.

This is a copy of a public record, reproduced as it was published. It is not legal advice, and it may not be the version a court would rely on. Check the official source before you cite it.