[Federal Register Volume 89, Number 4 (Friday, January 5, 2024)]
[Proposed Rules]
[Pages 830-857]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2023-27665]



[[Page 829]]

Vol. 89

Friday,

No. 4

January 5, 2024

Part II





Department of Transportation





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





National Highway Traffic Safety Administration





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





49 CFR Part 571





Advanced Impaired Driving Prevention Technology; Proposed Rule

  Federal Register / Vol. 89 , No. 4 / Friday, January 5, 2024 / 
Proposed Rules  

[[Page 830]]


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

DEPARTMENT OF TRANSPORTATION

National Highway Traffic Safety Administration

49 CFR Part 571

[Docket No. NHTSA-2022-0079]
RIN 2127-AM50


Advanced Impaired Driving Prevention Technology

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

ACTION: Advance notice of proposed rulemaking.

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

SUMMARY: This document initiates rulemaking that would gather the 
information necessary to develop performance requirements and require 
that new passenger motor vehicles be equipped with advanced drunk and 
impaired driving prevention technology through a new Federal Motor 
Vehicle Safety Standard (FMVSS). In this document, NHTSA presents its 
various activities related to preventing drunk and impaired driving and 
discusses the current state of advanced impaired driving technology. 
NHTSA also asks many questions to gather the information necessary to 
develop a notice of proposed rulemaking on advanced drunk and impaired 
driving technology.

DATES: Comments should be submitted no later than March 5, 2024.

ADDRESSES: You may submit comments to the docket number identified in 
the heading of this document by any of the following methods:
     Federal eRulemaking Portal: Go to https://www.regulations.gov. Follow the online instructions for submitting 
comments.
     Mail: Docket Management Facility: U.S. Department of 
Transportation, 1200 New Jersey Avenue SE, West Building Ground Floor, 
Room W12-140, Washington, DC 20590-0001.
     Hand Delivery or Courier: 1200 New Jersey Avenue SE, West 
Building Ground Floor, Room W12-140, between 9 a.m. and 5 p.m. ET, 
Monday through Friday, except Federal holidays.
     Fax: 202-493-2251.
    Instructions: All submissions must include the agency name and 
docket number. Note that all comments received will be posted without 
change to http://www.regulations.gov, including any personal 
information provided. Please see the Privacy Act discussion below. 
NHTSA will consider all comments received before the close of business 
on the comment closing date indicated above. To the extent possible, 
the agency will also consider comments filed after the closing date.
    Docket: For access to the docket to read background documents or 
comments received, go to https://www.regulations.gov at any time or to 
1200 New Jersey Avenue SE, West Building Ground Floor, Room W12-140, 
Washington, DC 20590, between 9 a.m. and 5 p.m., Monday through Friday, 
except Federal Holidays. Telephone: 202-366-9826. Confidential Business 
Information: If you wish to submit any information under a claim of 
confidentiality, submit these materials to NHTSA's Office of the Chief 
Counsel in accordance with 49 CFR part 512. All requests for 
confidential treatment must be submitted directly to the Office of the 
Chief Counsel. NHTSA is currently treating electronic submission as an 
acceptable method for submitting confidential business information to 
the agency under part 512. If you claim that any of the information or 
documents provided in your response constitutes confidential business 
information within the meaning of 5 U.S.C. 552(b)(4), or are protected 
from disclosure pursuant to 18 U.S.C. 1905, you may submit your request 
via email to Dan Rabinovitz in the Office of the Chief Counsel at 
dot.gov">Daniel.Rabinovitz@dot.gov. Do not send a hardcopy of a request for 
confidential treatment to NHTSA's headquarters.

FOR FURTHER INFORMATION CONTACT: Ms. Chontyce Pointer, Office of Crash 
Avoidance Standards, Telephone: 202-366-2987, Ms. Sara R. Bennett, 
Telephone: 202-366-7304 or Mr. Eli Wachtel, Telephone: 202-366-3065, 
Office of Chief Counsel. Address: National Highway Traffic Safety 
Administration, 1200 New Jersey Avenue SE, Washington, DC 20590.

SUPPLEMENTARY INFORMATION:

Table of Contents

I. Executive Summary
II. Introduction
    A. Background Information About Impaired Driving States
    B. Many Different Behavioral Strategies Exist, Yet Impaired 
Driving Persists
    C. NHTSA's Authority
III. Advanced Drunk and Impaired Driving Prevention Safety Problem
    A. Drunk Driving
    B. Distracted Driving
    C. Drowsy Driving
IV. Overview of Current Efforts To Address Drunk and Impaired 
Driving
    A. State and Federal Behavioral Prevention Activities
    1. Deterrence
    2. Prevention
    3. Communications Campaigns
    4. Alcohol and Drug Treatment, Monitoring, and Control
    B. Vehicle-Based Countermeasures
    1. Summary of Research on Vehicle-Based Countermeasures
    2. Passive Detection Methods and Available Technologies
    3. Proposed Vehicle Interventions Once Driver Impairment or BAC 
Is Detected
V. Summary of Other Efforts Related to Impaired Driving
VI. Privacy and Security
VII. Consumer Acceptance
VIII. General Questions for the Public
IX. Rulemaking Analyses and Notices
    A. Executive Order 12866, Executive Order 13563, Executive Order 
14094, and DOT Regulatory Policies and Procedures
    B. Privacy Act
    C. Regulation Identifier Number (RIN)

I. Executive Summary

    Alcohol-impaired driving \1\ is a major cause of crashes and 
fatalities on America's roadways. The National Highway Traffic Safety 
Administration (NHTSA) has been actively involved in addressing 
alcohol-impaired driving since the 1970s. Recent developments in 
vehicle technology present new opportunities to further reduce drunk 
and impaired driving crashes and fatalities or eliminate them 
altogether. Private and public researchers have also made significant 
progress on technologies that are capable of measuring and quantifying 
driver state and performance (e.g., hands on the steering wheel, visual 
gaze direction, lane position). However, harnessing these technologies 
for drunk and impaired driving detection and prevention remains a 
significant challenge. NHTSA's information gathering and research 
efforts have found that several technologies show promise for detecting 
various states of impairment, which for the purposes of this document 
are alcohol, drowsiness, and distraction. However, technological 
challenges, such as distinguishing between different impairment states, 
avoiding false positives, and determining appropriate prevention 
countermeasures, remain. Due to technology immaturity and a lack of 
testing protocols, drugged driving is not being considered in this 
advance notice of proposed rulemaking.
---------------------------------------------------------------------------

    \1\ This document discusses both drunk driving and alcohol-
impaired driving. Drunk driving, as used in this document, is 
understood to be operating a vehicle at or above the threshold of 
alcohol concentration in the blood established by law. Alcohol-
impaired driving describes the entire set of impairments of various 
driving-related skills and can occur at lower concentrations of 
alcohol.
---------------------------------------------------------------------------

    The Infrastructure Investment and Jobs Act (Bipartisan 
Infrastructure Law or BIL) directs NHTSA to issue a final rule 
establishing a Federal Motor Vehicle Safety Standard (FMVSS) that 
requires new passenger vehicles to have

[[Page 831]]

``advanced drunk and impaired driving prevention technology'' by 
2024.\2\ The BIL also provides that an FMVSS should be issued only if 
it meets the requirements of the National Traffic and Motor Vehicle 
Safety Act. (``Safety Act''). BIL defines the relevant technology as 
technology that can passively \3\ and accurately monitor driver 
performance to detect impairment or passively and accurately measure 
driver blood alcohol concentration (BAC) (or both in combination) and 
prevent or limit vehicle operation if impairment is detected. Given the 
current state of driver impairment detection technology, NHTSA is 
issuing this advance notice of proposed rulemaking (ANPRM) to inform a 
possible future FMVSS that can meet the requirements of the Vehicle 
Safety Act.
---------------------------------------------------------------------------

    \2\ Infrastructure Investment and Jobs Act, Public Law 117-58, 
135 Stat. 429 section 24220 (2021).
    \3\ For the purposes of this document, NHTSA uses the term 
``passive'' to mean that the system functions without direct action 
from vehicle occupants. Further information about the use of the 
term ``passive'' is available in the ``NHTSA's Authority'' section.
---------------------------------------------------------------------------

    This ANPRM presents a summary of NHTSA's knowledge of alcohol's 
impact on driver performance and seeks comment on a variety of issues 
related to the state of development of driver impairment detection 
technologies. It also sets forth the research and technological 
advancements necessary to develop a FMVSS for driver impairment. This 
document also presents three regulatory options for how the agency 
might mitigate driver impairment: blood alcohol content detection, 
impairment-detection (driver monitoring), or a combination of the two.

II. Introduction

    Driver impairment, as used in reference to motor vehicle safety, is 
a broad term that could encompass many different driver states that 
present operational safety risks.\4\ There is no clear and consistent 
engineering or industry definition of ``impairment.'' ``Impaired'' can 
mean anything that diminishes a person's ability to perform driving 
tasks and increases the likelihood of a crash. Considering this, driver 
impairment would include drunk and drugged driving,\5\ but it could 
also include drowsy driving, distracted driving,\6\ driving while 
experiencing an incapacitating medical emergency or condition, or any 
other factor that would diminish driver performance and increase 
potential crash risk. All these driver states present operational 
safety risks, and each presents differing problem sizes and degrees of 
risk, underlying causes, states of research, data demonstrating risks 
from that driver state, and potential vehicle technological 
countermeasures that could resolve or mitigate resulting operational 
safety risks. Additionally, not all states of driver impairment are 
immediately redressable, meaning that while a vehicle safety system 
might help a distracted or drowsy person pay attention again, it may 
not help a driver be less alcohol- or drug-impaired. This difference 
among the driver impairment states is particularly important when 
considering what type of standard or countermeasure would be the most 
appropriate.
---------------------------------------------------------------------------

    \4\ Part 392 of the Federal Motor Carrier Safety Regulations 
prohibits any driver from operating a commercial motor vehicle (CMV) 
while the driver's ability or alertness is so impaired, or so likely 
to become impaired, through fatigue, illness, or any other cause, as 
to make it unsafe for him/her to continue to operate the CMV. In 
addition, part 392 prohibits drivers from operating a CMV while (1) 
under the influence of, or using, specified drugs and other 
substances, and (2) under the influence of, or using, alcohol within 
specified time and concentration limits. Further, part 392 prohibits 
drivers from texting or using a hand-held mobile telephone while 
driving a CMV.
    \5\ Drugged driving is excluded from the scope and is discussed 
more in the Introduction, A. ``Background information about impaired 
driving states'' of this document.
    \6\ NHTSA has stated that distracted driving includes talking on 
mobile phones, texting, eating, and other non-driving activities.
---------------------------------------------------------------------------

    The negative economic and societal impacts related to impaired 
driving are enormous and devastating in the United States. Recent NHTSA 
research has identified the scope of causal factors associated with 
fatal and non-fatal injuries in crashes, revealing key differences 
among outcomes associated with reported contributory factors versus 
estimated causal factors.\7\ NHTSA estimates here that in 2021: 
approximately 12,600 traffic fatalities were ``caused by alcohol 
impairment,'' versus approximately 13,400 fatalities ``involving 
alcohol;'' 12,400 fatalities were ``due to distraction'' \8\, but and 
drowsy driving led to at least 684 fatalities. Differences in values 
associated with reported contributory factors versus causal factors are 
driven by offsetting forces; underreporting is a predominant issue for 
estimates of fatalities and injuries caused by distraction and possibly 
drowsy driving, while at least some fatalities and non-fatal injuries 
associated with alcohol and distraction likely had other causal 
factors. The enormous safety potential of addressing the three states 
of impaired driving considered here impels NHTSA's activities relating 
to driver impairment.
---------------------------------------------------------------------------

    \7\ Comprehensive economic costs account for the total societal 
harm associated with fatalities and injuries, including economic 
impacts and valuations of lost quality-of-life. See Blincoe, L., 
Miller, T., Wang, J.-S., Swedler, D., Coughlin, T., Lawrence, B., 
Guo, F., Klauer, S., & Dingus, T. (2023, February). The economic and 
societal impact of motor vehicle crashes, 2019 (Revised) (Report No. 
DOT HS 813 403). National Highway Traffic Safety Administration.
    \8\ Fatalities ``involving reported distraction'' refers to 
fatalities where a law enforcement officer reported a driver in a 
fatal crash as having been distracted at the time of the crash, 
which is associated with underreporting of all crashes, fatalities, 
and injuries involving and caused by distraction.
---------------------------------------------------------------------------

    With respect to alcohol impairment, NHTSA has been conducting 
behavioral research and implementing behavioral safety strategies and 
programs, public education, and enforcement campaigns to combat drunk 
driving. Despite these efforts, which have contributed to significant 
declines in fatalities over the past several decades, drunk driving 
remains a significant safety risk for the public. NHTSA is also engaged 
in technology-based research. This includes better understanding of the 
technological capabilities that measure drivers' eye movements and 
vehicle inputs. In addition, through the Driver Alcohol Detection 
System for Safety (DADSS) program, NHTSA is actively involved in 
cutting-edge research to help develop technology to quickly, 
accurately, and passively \9\ detect a driver's BAC. Upon completion of 
this development work, this technology may prevent drivers from 
shifting their vehicles into gear if they attempt to operate the 
vehicle at a BAC above the legal limit. NHTSA believes that the passive 
DADSS technology, still in development, may be one way to meet the BIL 
mandate, and that prevention of drunk driving is the best way to reduce 
the number of crashes and resulting fatalities and injuries that occur 
due to alcohol-impaired driving.
---------------------------------------------------------------------------

    \9\ The previous DADSS technology requires a directed breath 
toward a sensor to measure breath alcohol concentration (BrAC). The 
DADSS research and development effort is continuing to focus on 
developing technology that does not require a directed breath to 
detect the presence of alcohol.
---------------------------------------------------------------------------

    Concerted efforts by NHTSA, States, and other partners to implement 
proven strategies generated significant reductions in alcohol-impaired 
driving fatalities since the 1970s when NHTSA records began; but 
progress has stalled. Between 2011 and 2020, an average of almost 
10,500 people died each year in alcohol-impaired driving crashes. The 
agency has seen record increases in overall traffic fatalities over the 
last few years of the COVID-19 pandemic, likely reflecting increases in 
alcohol- and

[[Page 832]]

drug-impaired driving.\10\ While the causes of the recent fatality 
increases require further study and NHTSA continues to support 
strategies to change driver behavior, more must be done to reach our 
goal of zero traffic fatalities. Accordingly, in January 2022, DOT 
issued its National Roadway Safety Strategy (NRSS) to address the 
crisis of deaths on the nation's roadways.\11\ The NRSS adopts the Safe 
Systems Approach \12\ as the guiding paradigm to address roadway safety 
and focuses on five key objectives: safer people, safer roads, safer 
vehicles, safer speeds, and improved post-crash care. The Safe System 
Approach works by building and reinforcing multiple layers of 
protection both to prevent crashes from happening in the first place 
and to minimize the harm to those involved when crashes do occur.\13\ 
Drunk and impaired driving is an NRSS priority.\14\ The NRSS's Safe 
System Approach involves using all available tools, including 
education, outreach, enforcement, and engineering solutions, including 
motor vehicle technologies like alcohol, drowsiness, and visual 
distraction detection systems.\15\ Vehicle technologies that can help 
prevent and mitigate risky behaviors and driver impairment are a key 
element of the safer vehicles element of this approach. To complement 
behavioral campaigns, which have reduced, but not eliminated, driving 
while impaired,\16\ NHTSA is considering what technological 
countermeasures and performance requirements could be applied to motor 
vehicles that would achieve the NRSS safety objectives. Graph 1 
provides an overview of the alcohol-impaired fatalities since the early 
1980s.
---------------------------------------------------------------------------

    \10\ Office of Behavioral Safety Research (2021, October). 
Continuation of research on traffic safety during the COVID-19 
public health emergency: January-June 2021. (Report No. DOT HS 813 
210). National Traffic Safety Administration.
    \11\ Available at https://www.transportation.gov/NRSS.
    \12\ https://safety.fhwa.dot.gov/zerodeaths/docs/FHWA_SafeSystem_Brochure_V9_508_200717.pdf.
    \13\ United States Department of Transportation (2022, October). 
What is a safe system. Website: https://www.transportation.gov/NRSS/SafeSystem.
    \14\ It also observes that considerable progress in behavioral 
research has been made to advance the knowledge and understanding of 
the physiological effects of both alcohol- and drug-impaired 
driving.
    \15\ Id. at 16.
    \16\ Taylor, C.L., Byrne, A., Coppinger, K., Fisher, D., 
Foreman, C., & Mahavier, K. (2022, June). Synthesis of studies that 
relate amount of enforcement to magnitude of safety outcomes (Report 
No. DOT HS 813 274-A). National Highway Traffic Safety 
Administration.
[GRAPHIC] [TIFF OMITTED] TP05JA24.001

    Addressing each impaired driving state has its own set of unique 
challenges. For some, such as alcohol, technological solutions are not 
yet readily available that would consistently prevent a significant 
proportion of crashes caused by that impaired driving state. For 
others, such as distraction and drowsiness, there is evidence that 
police-reported crash data likely underestimate their role in crash 
causation. Amidst this uncertainty, the agency has many questions that 
must be answered to develop a proposal that will meet all statutory 
requirements and Departmental priorities.
    Given the breadth of impairment states, severities, detection 
technologies, and interventions, it is valuable to take this 
opportunity to clarify the scope of this effort. In view of the larger 
number of fatalities associated with alcohol impairment and the well-
defined legal thresholds and measurements available for alcohol 
impairment, as compared with other types of impairment, NHTSA is 
focusing this ANPRM on alcohol impairment.\17\ However, based on the 
language in BIL, NHTSA believes that Congress did not intend to limit 
NHTSA's efforts under BIL to alcohol impairment. Therefore, while 
alcohol impairment is the focus, this ANPRM also covers two additional 
impairment states: drowsy driving and distracted driving. NHTSA chose 
these states for two reasons. First, the size of the safety problem--in 
particular that of distracted driving--is immense. Second, certain 
sensor technologies that have the potential to detect or assist in 
detecting alcohol impairment and are or can be incorporated into driver 
monitoring systems (DMS) may also have the potential to detect drowsy 
and distracted driving. Including these impairment states in this 
effort therefore presents an opportunity to deliver significant 
additional safety benefits to the American people. These technological 
considerations are discussed in greater detail in Section IV. B. 
``Vehicle Based Countermeasures''.
---------------------------------------------------------------------------

    \17\ Meaning that metrics, such as BAC, currently exist to 
measure the type of impairment.
---------------------------------------------------------------------------

    Additionally, it is important to understand the many challenges 
with trying to identify and prevent the different types of impaired 
driving with a single performance standard. The agency is interested in 
learning more from commenters about what technologies and associated 
metrics might identify multiple types of

[[Page 833]]

impaired drivers.\18\ Also, as discussed in later sections, one of the 
options the agency is considering presents challenges with accurately 
differentiating alcohol impairment from other types of impairment, like 
drowsiness, assuming differentiation is desired and necessary to select 
appropriate alerts, warnings, or interventions. In later sections, we 
discuss different types of impairment that might be identified by a 
particular technology.
---------------------------------------------------------------------------

    \18\ The realization of additional safety benefits may depend on 
the performance requirements chosen by NHTSA, or the technological 
solution deployed by manufacturers.
---------------------------------------------------------------------------

    It is also important to be clear here that driving while impaired 
with drugs other than alcohol (drugged driving) is not within the scope 
of this ANPRM even though drug impairment is also a significant 
problem. Many different drugs can affect drivers, and current knowledge 
about the effects of each on driving performance is limited. 
Furthermore, the technology and testing protocols for drugs other than 
alcohol, in the driving context, are not mature enough to indicate the 
degree of impairment and the risk of crash involvement that results 
from the use of individual drugs. Therefore, drugged driving is beyond 
the scope of this rulemaking effort but remains important to the 
Department and agency as it addresses fatal and serious crashes. The 
complexities inherent in the drugged driving safety problem are 
discussed in more detail in the following section.

A. Background Information About Impaired Driving States

Drunk Driving
    Alcohol \19\ impairment can lead to altered and negative behaviors, 
as well as physical conditions that increase the risk of unintentional 
injuries, particularly when driving. Alcohol is known to impair various 
driving-relevant abilities such as perception, visuomotor coordination, 
psychomotor performance, information processing and decision making, 
and attention management.\20\ When consumed, alcohol is absorbed from 
the stomach and distributed by the blood stream throughout the 
body.\21\ BAC is measured as the weight of alcohol in a certain volume 
of blood and expressed in grams per deciliter (g/dL).\22\ The rise and 
fall of alcohol in the bloodstream (and thus, the BAC) depends on the 
interplay between various factors that determine the metabolization of 
alcohol within the person's body including frequency and amount of 
alcohol consumed, age, gender, body mass, consumption of other food, 
genetic factors, and time since alcohol consumption.\23\
---------------------------------------------------------------------------

    \19\ The term alcohol in this report refers to ethyl alcohol, or 
ethanol, which is the principal ingredient in alcoholic drinks and 
the substance measured to determine blood alcohol concentration.
    \20\ Moskowitz, H., & Burns, M. (1990). Effects of alcohol on 
driving performance. Alcohol Health & Research World, 14(1), 12-15.
    \21\ Paton, A. (2005). Alcohol in the body. BMJ, 330(7482), 85-
87.
    \22\ National Highway Traffic Safety Administration. (2016). The 
ABCs of BAC: A guide to understanding blood alcohol concentration 
and alcohol impairment. Retrieved from https://www.nhtsa.gov/document/theabcsofbac.
    \23\ Zakhari, S. (2006). Overview: how is alcohol metabolized by 
the body? Alcohol research & health, 29(4), 245.
---------------------------------------------------------------------------

    In the United States, in general, a BAC of .08 g/dL and higher in 
drivers is defined as legally impaired \24\ and a condition for arrest 
(in Utah, a BAC at or above .05 g/dL is the illegal limit). However, 
alcohol-impairment of various driving-related skills can occur at lower 
concentrations, and alcohol-impaired drivers can pose serious injury 
risks to themselves and others with any amount of alcohol in their 
bodies. As alcohol BAC levels rise in a person's system, the negative 
effects on the central nervous system increase.\25\ Alcohol affects the 
body in a way that negatively impacts the skills needed for a person to 
drive safely because it impairs the function of the brain that relates 
to thinking, reasoning, and muscle coordination.\26\ Table 1 provides 
an overview of the typical and predictable effects on driving over a 
range of BAC levels.
---------------------------------------------------------------------------

    \24\ 23 U.S.C. 163.
    \25\ https://www.nhtsa.gov/risky-driving/drunk-driving#the-issue-alcohol-effects.
    \26\ https://www.nhtsa.gov/risky-driving/drunk-
driving#:~:text=Alcohol%20is%20a%20substance%20that,the%20central%20n
ervous%20system%20increase.

              Table 1--Effects of Alcohol on Driving 27 28
------------------------------------------------------------------------
 Blood alcohol concentration                         Predictable effects
           (g/dL)                Typical effects         on driving
------------------------------------------------------------------------
.02.........................   Some loss     Decline in
                               of judgment.          visual functions
                               Relaxation.   (rapid tracking of
                               Slight body   a moving target).
                               warmth.               Decline in
                               Altered       ability to perform
                               mood.                 two tasks at the
                                                     same time (divided
                                                     attention).
.05.........................   Exaggerated   Reduced
                               behavior.             coordination.
                               May have      Reduced
                               loss of small-        ability to track
                               muscle control        moving objects.
                               (e.g., focusing       Difficulty
                               your eyes).           steering.
                               Impaired      Reduced
                               judgment.             response to
                               Euphoric      emergency driving
                               feeling.              situations.
                               Lowered
                               alertness.
                               Release of
                               inhibition.
.08.........................   Muscle        Reduced
                               coordination          concentration.
                               becomes poor (e.g.,   Short-term
                               balance, speech,      memory loss.
                               vision, reaction      Reduced and
                               time, and hearing).   erratic speed
                               Harder to     control.
                               detect danger.        Reduced
                               Impaired      information
                               judgment, self-       processing
                               control, reasoning,   capability (e.g.,
                               and memory.           signal detection,
                                                     visual search).
                                                     Impaired
                                                     perception.
.10.........................   Clear         Reduced
                               deterioration of      ability to maintain
                               reaction time and     lane position and
                               control.              brake
                                                     appropriately.
                               Slurred
                               speech, poor
                               coordination, and
                               slowed thinking.
.15.........................   Far less      Substantial
                               muscle control than   impairment in
                               normal.               vehicle control,
                               Vomiting      attention to
                               may occur (unless     driving task, and
                               this level is         in necessary visual
                               reached slowly or a   and auditory
                               person has            information
                               developed a high      processing.
                               tolerance for
                               alcohol).

[[Page 834]]

 
                               Significant
                               loss of balance.
------------------------------------------------------------------------

    The driving skill decrements in Table 1 provide a means of 
approximating the impairment correlated with BAC levels. However, BAC 
is a measure of the amount of alcohol in the bloodstream rather than a 
reliable indicator of the degree of impairment.29 30 At 
least two factors contribute to the lack of a precise one-to-one 
correlation between BAC and impairment. First, regular drinkers may 
learn strategies for more cautious driving to compensate for their 
perceived skill decrements.31 32 Second, there is also 
empirical evidence that some regular drinkers develop a higher 
tolerance to alcohol, which results in less apparent declines in 
cognitive and motor performance after consuming low to moderate 
doses.\33\ Therefore, BAC levels provide an imperfect measurement of 
probable impairment. Nearly two thirds of all alcohol-impaired 
fatalities involve high blood alcohol levels with a BAC level at or 
greater than 0.15 g/dL.\34\ Yet even a small amount of alcohol can 
affect an individual's driving ability. In 2020, there were 2,041 
people killed in alcohol-related crashes where a driver had a BAC level 
of .01 to .07 g/dL.
---------------------------------------------------------------------------

    \27\ Table 1 should be used as a reference point for population-
level analysis. The outlined effects may apply to certain 
individuals, but for the reasons discussed above, may vary from 
individual to individual. It should also be noted that while some 
effects are listed at multiple BACs (e.g., difficulty steering), the 
effects are more likely to occur and more severe at higher BACs. 
Information in this table shows the BAC level at which the effect 
usually is first observed.
    \28\ Adapted from National Highway Traffic Safety 
Administration. (2016). The ABCs of BAC: A guide to understanding 
blood alcohol concentration and alcohol impairment. Retrieved from 
https://www.nhtsa.gov/document/theabcsofbac.
    \29\ Fillmore, M.T., & Vogel[hyphen]Sprott, M.J.A.C. (1998). 
Behavioral impairment under alcohol: cognitive and pharmacokinetic 
factors. Alcoholism: Clinical and experimental research, 22(7), 
1476-1482.
    \30\ Nicholson, M.E., Wang, M., Airhihenbuwa, C.O., Mahoney, 
B.S., Christina, R., & Maney, D.W. (1992a). Variability in 
behavioral impairment involved in the rising and falling BAC curve. 
Journal of Studies on Alcohol, 53(4), 349-356.
    \31\ Burian, S.E., Hensberry, R., & Liguori, A. (2003). 
Differential effects of alcohol and alcohol expectancy on 
risk[hyphen]taking during simulated driving. Human 
Psychopharmacology: Clinical and Experimental, 18(3), 175-184.
    \32\ Vogel-Sprott, M. (1997). Is behavioral tolerance learned? 
Alcohol health and research world, 21(2), 161.
    \33\ Id.
    \34\ https://crashstats.nhtsa.dot.gov/Api/Public/ViewPublication/813120.
---------------------------------------------------------------------------

    State alcohol impairment laws and alcohol detection devices focus 
on measuring the alcohol concentration in BAC and breath alcohol 
concentration (BrAC). These are the two measurements that State laws 
and alcohol detection devices utilize to determine whether someone is 
considered driving over the legal limit (i.e., whether the person can 
be considered driving drunk, with ``drunk'' being defined as above the 
threshold of alcohol concentration established by law). BrAC is 
measured with a breath test device that measures the amount of alcohol 
in a driver's breath. BAC is usually measured via a blood test. 
Technology is under development that would allow for measurement in new 
ways. For example, one technology uses touch- or tissue-based detection 
of light absorption at pre-selected wavelengths from a beam of light 
reflected from within the skin tissue after an optical module is 
touched. In other words, BAC is calculated either by a blood test or, 
in the future, after someone touches a sensor and that sensor 
calculates the BAC level in the person's blood. NHTSA acknowledges that 
people may be affected by alcohol at levels below the legal limit used 
in most States (.08 g/dL), which is why the agency noted above that 
there are still crashes where alcohol is involved, but the driver's BAC 
was lower than the legal limit. NHTSA discusses each of these 
measurements and the vehicle technologies that can measure them later 
in this document.
Drugged Driving
    Drugged driving, though important to prevent, is not included in 
the scope of this advance notice of proposed rulemaking. There are 
several complexities to understanding drugged or drug-involved 
driving.\35\ To begin, the term drugs can refer to over-the-counter 
medications, prescription medications, and illicit drugs. Also, the 
mere presence of a drug in a person's system does not necessarily 
indicate impairment. Currently, most information collected on drugs 
within the driving context can provide information only on whether a 
driver is ``drug positive.'' \36\ The presence of some drugs can remain 
in the body a considerable time after use, so presence at any point 
does not necessarily mean the person was or remains impaired by the 
drug.\37\ For some drivers, certain prescribed medications, which may 
be included in a positive drug test result, may be necessary for safe 
driving.
---------------------------------------------------------------------------

    \35\ Berning, A., Smith, R. Drexler, M., Wochinger, K. (2022). 
Drug Testing and Traffic Safety: What You Need to Know. United 
States. Department of Transportation. (Report No. DOT HS 813 264). 
Washington, DC. National Highway Traffic Safety Administration.
    \36\ ``Drug positive'' indicates that a driver has tested 
positive for a drug (or drugs). However, testing positive for a drug 
does not indicate impairment nor any degree of potential impairment.
    \37\ Berning, et al., 2022.
---------------------------------------------------------------------------

    Further, there are a wide range of drugs other than alcohol that 
can be used by drivers. There is limited research on crash risk and how 
each specific drug affects driving related skills, and the technology 
and testing protocols are not mature in the driving context. Today's 
knowledge about the effects of any drug other than alcohol on driving 
performance remains insufficient to draw connections between their use, 
driving performance, and crash risk.\38\
---------------------------------------------------------------------------

    \38\ Compton, R., Vegega, M. Smither, D. (2009). Drug Impaired 
Driving: Understanding the Problem and Ways to Reduce It. DOT HS 811 
268. Washington, DC. NHTSA.
---------------------------------------------------------------------------

    Recently, more research has been directed to the effects of 
cannabis, and specifically Tetrahydrocannabinol (THC), the active 
component of cannabis that can cause impairing effects on driving that 
might lend themselves to the development of THC-impaired driving 
detection techniques, like those that have been developed by NHTSA for 
use by law enforcement for alcohol-impaired driving.39 40 
However, many of these effects may also be caused by alcohol, other 
drugs, and other impairment states like distraction, drowsiness, and 
incapacitation. Current knowledge about the effects of cannabis on 
driving is insufficient to allow specification of a simple measure of

[[Page 835]]

driving impairment outside of controlled conditions.\41\
---------------------------------------------------------------------------

    \39\ Harris, D.H., Dick, R.A., Casey, A.M., and Jarosz, C.J. 
(1980) The Visual Detection of Driving While Intoxicated: Field Test 
of Visual Cues and Detection Methods. DOT-HS-905-620. Washington, 
DC: NHTSA.
    \40\ Stuster, J.W. (1997). The Detection of DWI at BACs Below 
0.10. (Report No. DOT HS 808 654). Washington, DC: U.S. Department 
of Transportation, NHTSA.
    \41\ Compton, R. (2017). Marijuana-Impaired Driving--A Report to 
Congress. DOT HS 812 440. Washington, DC. NHTSA.
---------------------------------------------------------------------------

    Given these challenges, the agency is not yet considering 
developing performance requirements and a FMVSS for drug impaired 
driving.
Distracted Driving
    NHTSA defines ``driver distraction'' as inattention that occurs 
when drivers divert their attention away from the driving task to focus 
on another activity.\42\ In general, distractions derive from a variety 
of sources including electronic devices, such as navigation systems and 
mobile phones, as well as conventional distractions such as sights or 
events external to the vehicle, interactions with passengers, and 
eating or drinking. These distracting tasks can affect drivers in 
different ways, and can be categorized into the following types:
---------------------------------------------------------------------------

    \42\ 78 FR 24,817 (proposed April 26, 2013). Visual-Manual NHTSA 
Driver Distraction Guidelines for In-Vehicle Electronic Devices.

--Visual distraction: Tasks that require or cause the driver to look 
away from the roadway to visually obtain information.
--Manual distraction: Tasks that require or cause the driver to take a 
hand off the steering wheel and manipulate a device or object.
--Cognitive distraction: Tasks that require or cause the driver to 
divert their mental attention away from the driving task.

    Research has shown that eyes-off-road time provides an objective 
measure of visual distraction, which has a demonstrated relationship 
with crash risk. Analyses of naturalistic data have shown that eyes-
off-road times greater than 2.0 seconds have been shown to increase 
crash risk at a statistically significant level. Further, the risk of a 
crash or near-crash event increases rapidly as eyes-off-road time 
increases above 2.0 seconds.\43\ There has been little agreement in the 
field regarding how to identify and measure cognitive distraction, 
however.\44\
---------------------------------------------------------------------------

    \43\ Klauer, S.G., Dingus, T.A., Neale, V.L., Sudweeks, J.D., & 
Ramsey, D.J. (2006). The impact of driver inattention on near-crash/
crash risk: An analysis using the 100-car naturalistic driving study 
data (No. DOT HS 810 594). United States. Department of 
Transportation. National Highway Traffic Safety Administration.
    \44\ Young, R. (2012). Cognitive distraction while driving: A 
critical review of definitions and prevalence in crashes. SAE 
International journal of passenger cars-electronic and electrical 
systems, 5(2012-01-0967), 326-342.
---------------------------------------------------------------------------

    Distraction can negatively affect driving performance in various 
ways depending on the type(s) of distraction(s), the demands of the 
driving task and the secondary task(s), and other factors. These 
effects can include decrements to reaction time, hazard detection, 
lateral control (i.e., lane-keeping), and longitudinal control (e.g., 
speed or following gap), as well as changes to eye movements (e.g., 
glance patterns, eyes-off-road time), and driver 
workload.45 46 47 For example, a meta-analysis aggregating 
the results of 18 simulator experiments and naturalistic driving 
studies reported that typing or reading text messages while driving 
significantly slowed reaction time, increased lane deviations, and 
increased eyes-off-road time.\48\
---------------------------------------------------------------------------

    \45\ Regan, M.A., Lee, J.D., & Young, K. (2008). Driver 
distraction: Theory, effects, and mitigation. CRC press.
    \46\ Young, K. & Regan, M. (2007). Driver distraction: A review 
of the literature. In: I.J. Faulks, M. Regan, M. Stevenson, J. 
Brown, A. Porter & J.D. Irwin (Eds.). Distracted driving. Sydney, 
NSW: Australasian College of Road Safety. Pages 379-405.)
    \47\ Papantoniou, P., Papadimitriou, E., & Yannis, G. (2017). 
Review of driving performance parameters critical for distracted 
driving research. Transportation research procedia, 25, 1796-1805.
    \48\ Caird, J.K., Johnston, K.A., Willness, C.R., Asbridge, M., 
& Steel, P. (2014). A meta-analysis of the effects of texting on 
driving. Accident Analysis & Prevention, 71, 311-318.
---------------------------------------------------------------------------

    These degradations in driving performance due to distraction have 
been shown to translate into an increased risk of crash or near-crash 
involvement. An analysis of the second Strategic Highway Research 
Program (SHRP2) Naturalistic Driving Study \49\ found that, when 
compared to alert and attentive driving, the odds of a crash were 
doubled when a driver was distracted, with secondary tasks that divert 
the driver's eyes away from the forward roadway having the largest 
multiplicative increase in crash risk (e.g., dialing a handheld mobile 
phone increased crash risk by 12.2x, reading/writing increased crash 
risk by 9.9x, and reaching for a non-mobile device increased crash risk 
by 9.1x).\50\ A similar study found that the use of handheld mobile 
phones in general, and specifically performing tasks with visual and 
manual elements (such as texting), were significantly associated with 
increased crash involvement.\51\
---------------------------------------------------------------------------

    \49\ SHRP2 large scale data collection effort. Data were 
collected from over 3,000 drivers. For more information see: https://www.fhwa.dot.gov/goshrp2/Solutions/All/NDS/Concept_to_Countermeasure__Research_to_Deployment_Using_the_SHRP2_Safety_Data.
    \50\ Dingus, T.A., Guo, F., Lee, S., Antin, J.F., Perez, M., 
Buchanan-King, M., & Hankey, J. (2016). Driver crash risk factors 
and prevalence evaluation using naturalistic driving data. 
Proceedings of the National Academy of Sciences, 113(10), 2636-2641.
    \51\ Owens, J.M., Dingus, T.A., Guo, F., Fang, Y., Perez, M., & 
McClafferty, J. (2018). Crash risk of cell phone use while driving: 
A case-crossover analysis of naturalistic driving data. AAA 
Foundation for Traffic Safety. https://aaafoundation.org/wp-content/uploads/2018/01/CellPhoneCrashRisk_FINAL.pdf.
---------------------------------------------------------------------------

    Outside of naturalistic driving studies, the role of distraction in 
crashes can be difficult to determine because pre-crash distractions 
often leave no evidence for law enforcement officers or crash 
investigators to observe, and drivers are often reluctant to admit to 
having been distracted prior to a crash. A NHTSA analysis of causal 
factors for fatal and non-fatal injuries estimates that 29 percent of 
fatal and non-fatal injuries are due to distraction. This estimate is 
over three times larger than the police-reported share of fatal crashes 
involving distraction (8.2% of all traffic fatalities in 2021, as 
reported in the Fatality Analysis Reporting System (FARS)). The 
difference between these values reflects the large role that 
underreporting of distraction plays in identifying distraction as a 
traffic safety risk. Distraction-affected crashes are a relatively new 
measure that focuses on distractions that are most likely to influence 
crash involvement, such as dialing a mobile phone or texting, and 
distraction by an outside person/event.\52\ It is also worth noting 
that many studies on distracted driving and its consequences were 
conducted prior to the proliferation of smartphones, navigation apps 
and devices, and built-in technologies. Consequently, it is possible 
that distraction-related crashes will escalate as the prevalence, 
diversity, and use of new technologies continue to increase.
---------------------------------------------------------------------------

    \52\ NHTSA. (2012). Blueprint for ending distracted driving 
(Report No. DOT HS 811 629). www.nhtsa.gov/sites/nhtsa.dot.gov/files/811629.pdf.
---------------------------------------------------------------------------

    Currently, text messaging is banned for drivers in 48 States, 
handheld mobile phone use is prohibited in 31 States (e.g., hands-free 
laws), and 36 States prohibit all mobile phone use by novice 
drivers.\53\ When paired with high visibility enforcement campaigns, 
mobile phone and text messaging laws were shown to reduce drivers' use 
of handheld mobile phones in several pilot programs.\54\
---------------------------------------------------------------------------

    \53\ https://www.ghsa.org/state-laws/issues/distracted%20driving.
    \54\ Chaudhary, N.K., Casanova-Powell, T.D., Cosgrove, L., 
Reagan, I., & Williams, A. (2014, March). Evaluation of NHTSA 
distracted driving demonstration projects in Connecticut and New 
York (Report No. DOT HS 81 635). National Highway Traffic Safety 
Administration.
---------------------------------------------------------------------------

Drowsy Driving
    Drowsiness is ``the intermediate state between wakefulness and 
sleep as defined electro-physiologically by the pattern of brain waves 
(e.g., electroencephalogram--EEG), eye

[[Page 836]]

movements, and muscle activity.'' \55\ Driver drowsiness has a variety 
of biological contributors, including sleeplessness or sleep 
deprivation, changes in sleep patterns, untreated sleep disorders, and 
use of drugs with sedative effects, including alcohol.\56\ Driver 
drowsiness can lead to impairments in cognitive and psychomotor speed, 
attentional distribution, vigilance, and working memory.\57\
---------------------------------------------------------------------------

    \55\ Johns, M.W. (2000). A sleep physiologist's view of the 
drowsy driver. Transportation research part F: traffic psychology 
and behaviour, 3(4), 241-249.
    \56\ https://www.cdc.gov/sleep/features/drowsy-driving.html.
    \57\ Goel, N., Rao, H., Durmer, J.S., & Dinges, D.F. (2009, 
September). Neurocognitive consequences of sleep deprivation. In 
Seminars in neurology (Vol. 29, No. 04, pp. 320-339).
---------------------------------------------------------------------------

    Within the driving context, performance measures that have shown 
drowsiness-related decrements include lane keeping and lane 
departures,\58\ slower driving speed and decreased speed stability,\59\ 
and longer reaction times.\60\ Drowsiness can progress into microsleep 
and sleep events, in which the driver may experience cognitive and/or 
visual lapses of increasing duration, posing increasingly serious risks 
of crash involvement.\61\ Situational factors such as increasing time 
on task and monotony of driving environment can contribute to driver 
drowsiness.\62\
---------------------------------------------------------------------------

    \58\ Fairclough SH, Graham R. Impairment of driving performance 
caused by sleep deprivation or alcohol: A comparative study. Human 
Factors. 1999; 41(1):118-128.
    \59\ Soares, S., Monteiro, T., Lobo, A., Couto, A., Cunha, L., & 
Ferreira, S. (2020). Analyzing driver drowsiness: From causes to 
effects. Sustainability, 12(5), 1971.
    \60\ Kozak, K., Curry, R., Greenberg, J., Artz, B., Blommer, M., 
& Cathey, L. (2005, September). Leading indicators of drowsiness in 
simulated driving. In Proceedings of the Human Factors and 
Ergonomics Society Annual Meeting (Vol. 49, No. 22, pp. 1917-1921).
    \61\ Blaivas, A. J., Patel, R., Hom, D., Antigua, K., & 
Ashtyani, H. (2007). Quantifying microsleep to help assess 
subjective sleepiness. Sleep medicine, 8(2), 156-159.
    \62\ Thiffault, P., & Bergeron, J. (2003). Monotony of road 
environment and driver fatigue: a simulator study. Accident Analysis 
& Prevention, 35(3), 381-391.
---------------------------------------------------------------------------

    While driver drowsiness cannot be measured directly, it can be 
indirectly detected and measured using both objective and subjective 
measures. Objective measures related to driver drowsiness include 
physiological signals of brain activity (e.g., EEG, EKG,\63\, EOG 
\64\), other biological markers (e.g., heart rate, respiration, 
galvanic skin response), measures based on observations of the driver 
(e.g., head pose, eye closure, blink rate), and vehicle control 
measures (e.g., steering wheel angle, lane departures, speed 
variation). Using multiple measures in combination may increase the 
accuracy and reliability of drowsiness detection.\65\
---------------------------------------------------------------------------

    \63\ Electrocardiogram (EKG or ECG).
    \64\ Electroocoulogram (EOG).
    \65\ Albadawi, Y., Takruri, M., & Awad, M. (2022). A review of 
recent developments in driver drowsiness detection systems. Sensors, 
22(5), 2069.
---------------------------------------------------------------------------

    Among brain activity measures, EEG is most frequently used to 
measure brain states, including drowsiness.\66\ While factors such as 
individual differences, time of day, and other non-drowsiness related 
brain activity can be confounding factors, signal markers in EEG data 
can indicate the presence and degree of drowsiness.\67\ While EEG and 
some other direct brain measures are advancing in their ease of use and 
portability, they are generally not feasible for in-vehicle use at the 
present time.
---------------------------------------------------------------------------

    \66\ De Gennaro, L., Ferrara, M., Curcio, G., & Cristiani, R. 
(2001). Antero-posterior EEG changes during the wakefulness-sleep 
transition. Clinical neurophysiology, 112(10), 1901-1911.
    \67\ Stancin, I., Cifrek, M., & Jovic, A. (2021). A review of 
EEG signal features and their application in driver drowsiness 
detection systems. Sensors, 21(11), 3786.
---------------------------------------------------------------------------

    Camera-based-systems, however, are increasingly feasible and common 
in vehicles. Camera-based systems have the potential to measure a wide 
array of driver head and face characteristics that may be indicative of 
drowsiness, including driver head pose, driver gaze activity (e.g., 
number and distribution of glances), the percentage of time the 
driver's eyes are closed (i.e., PERCLOS \68\), blink speed, eye closure 
duration, yawns, and other facial expressions.
---------------------------------------------------------------------------

    \68\ Hanowski, R.J., Bowman, D., Alden, A., Wierwille, W.W., & 
Carroll, R. (2008). PERCLOS+: Development of a robust field measure 
of driver drowsiness. In 15th World Congress on Intelligent 
Transport Systems and ITS America's 2008 Annual Meeting.
---------------------------------------------------------------------------

    As noted previously, driver drowsiness tends to become 
progressively more pronounced over time. The progressive nature of 
driver drowsiness means that it is possible to estimate a driver's 
future drowsiness state--seconds or even more than a minute into the 
future--based on their current drowsiness state. Researchers have used 
various physiological and behavioral measures to develop models to 
predict drivers' subjective drowsiness,\69\ predict the occurrence of 
microsleeps,\70\ and predict drowsiness as determined by coders looking 
at video of drivers' faces.\71\ While limited research exists to 
demonstrate the feasibility of drowsiness state prediction under real-
world driving conditions, further developments in drowsiness prediction 
could allow vehicles to provide alerts and interventions to reduce the 
risks of drowsy driving before they become severe.
---------------------------------------------------------------------------

    \69\ Murata, A., Ohta, Y., & Moriwaka, M. (2016). Multinomial 
logistic regression model by stepwise method for predicting 
subjective drowsiness using performance and behavioral measures. In 
Proceedings of the AHFE 2016 International Conference on Physical 
Ergonomics and Human Factors, July 27-31, 2016, Walt Disney 
World[supreg], Florida, USA (pp. 665-674).
    \70\ Watson, A., & Zhou, G. (2016, June). Microsleep prediction 
using an EKG capable heart rate monitor. In 2016 IEEE First 
International Conference on Connected Health: Applications, Systems 
and Engineering Technologies (CHASE) (pp. 328-329). IEEE.
    \71\ de Naurois, C.J., Bourdin, C., Stratulat, A., Diaz, E., & 
Vercher, J.L. (2019). Detection and prediction of driver drowsiness 
using artificial neural network models. Accident Analysis & 
Prevention, 126, 95-104.
---------------------------------------------------------------------------

    As the detection and prediction of driver drowsiness within a 
vehicle becomes increasingly feasible, it is possible to consider 
potential vehicle-based countermeasures to reduce risk. While there is 
limited research investigating interventions to reduce drowsy driving 
risks, evidence suggests that auditory,\72\ visual,\73\ and seat belt 
vibration \74\ warnings can help to improve drowsy drivers' driving 
performance, and that there may be benefits to multi-staged warnings 
relative to single-stage warnings.\75\
---------------------------------------------------------------------------

    \72\ Berka, C., Levendowski, D., Westbrook, P., Davis, G., 
Lumicao, M.N., Ramsey, C., . . . & Olmstead, R.E. (2005, July). 
Implementation of a closed-loop real-time EEG-based drowsiness 
detection system: Effects of feedback alarms on performance in a 
driving simulator. In 1st International Conference on Augmented 
Cognition, Las Vegas, NV (pp. 151-170).
    \73\ Fairclough, S.H., & van Winsum, W. (2000). The influence of 
impairment feedback on driver behavior: A simulator study. 
Transportation human factors, 2(3), 229-246.
    \74\ Arimitsu, S., Sasaki, K., Hosaka, H., Itoh, M., Ishida, K., 
& Ito, A. (2007). Seat belt vibration as a stimulating device for 
awakening drivers. IEEE/ASME Transactions on mechatronics, 12(5), 
511-518.
    \75\ Gaspar, J.G., Brown, T.L., Schwarz, C.W., Lee, J.D., Kang, 
J., & Higgins, J.S. (2017). Evaluating driver drowsiness 
countermeasures. Traffic injury prevention, 18(sup1), S58-S63.
---------------------------------------------------------------------------

B. Many Different Behavioral Strategies Exist, Yet Impaired Driving 
Persists

    Alcohol-impaired driving is a behavioral issue, and in general, 
changing human behavior is particularly challenging.\76\ NHTSA has made 
considerable progress in behavioral research to advance the knowledge 
and understanding of the physiological

[[Page 837]]

effects of alcohol impairment on driving. Additionally, NHTSA has taken 
a multi-pronged approach to trying to eliminate alcohol-impaired 
driving. Four basic strategies are used to reduce impaired driving 
crashes and driving under the influence:
---------------------------------------------------------------------------

    \76\ In the medical field, the National Institutes of Health 
(NIH) established a program nearly 15 years ago to study behavior 
change and try to identify the most successful mechanisms that 
result in the most behavior change. They understood the problem and 
developed interventions, but they really did not understand why the 
intervention worked for some but not others. See https://scienceofbehaviorchange.org/what-is-sobc/ for an example of a NIH 
project focusing on the science behind changing human behaviors.
---------------------------------------------------------------------------

    1. Deterrence: enact, publicize, enforce, and adjudicate laws 
prohibiting impaired driving so people choose not to drive impaired;
    2. Prevention: reduce drinking and drug use to keep drivers from 
becoming impaired;
    3. Communications and outreach: inform the public of the dangers of 
impaired driving and establish positive social norms that make driving 
while impaired unacceptable; and
    4. Alcohol and drug treatment: reduce alcohol and drug dependency 
or addiction among drivers.\77\
---------------------------------------------------------------------------

    \77\ https://www.nhtsa.gov/book/countermeasures/alcohol-and-drug-impaired-driving/strategies-reduce-impaired-driving.
---------------------------------------------------------------------------

    NHTSA uses and encourages a variety of different behavioral 
strategies, focusing on those strategies that are demonstrably 
effective.\78\ Some strategies, like laws, enforcement, criminal 
prosecution, and offender treatment and monitoring, have a deterrent 
effect. Other strategies focus on prevention, intervention, 
communications, and outreach.\79\
---------------------------------------------------------------------------

    \78\ See https://www.nhtsa.gov/book/countermeasures/alcohol-and-drug-impaired-driving/countermeasures.
    \79\ Id.
---------------------------------------------------------------------------

C. NHTSA's Authority

    The National Traffic and Motor Vehicle Safety Act provides NHTSA 
with broad authority to address motor vehicle safety problems like 
driver impairment. Under the National Traffic and Motor Vehicle Safety 
Act (49 U.S.C. 30101 et seq.) (Safety Act), the Secretary of 
Transportation is responsible for prescribing motor vehicle safety 
standards that are practicable, meet the need for motor vehicle safety, 
and are stated in objective terms.\80\ ``Motor vehicle safety'' is 
defined in the Safety Act as ``the performance of a motor vehicle or 
motor vehicle equipment in a way that protects the public against 
unreasonable risk of accidents occurring because of the design, 
construction, or performance of a motor vehicle, and against 
unreasonable risk of death or injury in an accident, and includes 
nonoperational safety of a motor vehicle.'' \81\ ``Motor vehicle safety 
standard'' means a minimum standard for motor vehicle or motor vehicle 
equipment performance.\82\ When prescribing such standards, the 
Secretary must consider all relevant, available motor vehicle safety 
information.\83\ The Secretary must also consider whether a proposed 
standard is reasonable, practicable, and appropriate for the types of 
motor vehicles or motor vehicle equipment for which it is prescribed 
and the extent to which the standard will further the statutory purpose 
of reducing traffic crashes and associated deaths.\84\ The 
responsibility for promulgation of FMVSS is delegated to NHTSA.\85\
---------------------------------------------------------------------------

    \80\ 49 U.S.C. 30111(a).
    \81\ 49 U.S.C. 30102(a)(9).
    \82\ Section 30102(a)(10).
    \83\ Section 30111(b)(1).
    \84\ Section 30111(b)(3)-(4).
    \85\ 49 CFR 1.95.
---------------------------------------------------------------------------

    To meet the Safety Act's requirement that standards be 
``practicable,'' NHTSA must consider several factors, including 
technological and economic feasibility \86\ and consumer 
acceptance.\87\ Technological feasibility considerations counsel 
against standards for which ``many technical problems have been 
identified and no consensus exists for their resolution . . . .'' \88\ 
However, it does not require that the technology be developed, tested, 
and ready for deployment at the time the standard is promulgated. 
Economic feasibility considerations focus on whether the cost on 
industry to comply with the standard would be prohibitive. Finally, 
NHTSA must consider consumer acceptance. In particular, the U.S. Court 
of Appeals for the D.C. Circuit has noted that ``motor vehicle safety 
standards cannot be considered practicable unless we know . . . that 
motorists will avail themselves of the safety system. And it would be 
difficult to term `practicable' a system . . . that so annoyed 
motorists that they deactivated it.'' \89\ NHTSA also understands that 
if consumers do not accept a required safety technology, the technology 
will not deliver the safety benefits that NHTSA anticipates.\90\
---------------------------------------------------------------------------

    \86\ See, e.g., Paccar, Inc. v. Nat'l Highway Traffic Safety 
Admin., 573 F.2d 632, 634 n.5 (`` `Practicable' is defined to 
require consideration of all relevant factors, including 
technological ability to achieve the goal of a particular standard 
as well as consideration of economic factors.'') (citations and 
quotations omitted).
    \87\ Pac. Legal Found. v. Dep't of Transp., 593 F.2d 1338, 1345 
(D.C. Cir. 1979) (noting in reference to practicable and meet the 
need for safety, that ``the agency cannot fulfill its statutory 
responsibility unless it considers popular reaction.'').
    \88\ Simms v. Nat'l Highway Traffic Safety Admin., 45 F.3d 999, 
1011 (6th Cir. 1995).
    \89\ Pac. Legal Found., 593.F.2d at 1346. The court also noted 
that the Secretary could reasonably anticipate consumers to be more 
willing to accept airbags than automatic seatbelts and seatbelt 
interlocks because airbags impose less on the driver and research 
indicated a lower deactivation rate for airbags than interlock 
systems.
    \90\ See, 82 FR 3854, 3920. Due to the nature of the technology, 
consumer acceptance was a key factor discussed in the 2017 NPRM on 
vehicle-to-vehicle (V2V) technology. NHTSA also conducted 
significant research into consumer acceptance and beliefs about V2V 
technology.
---------------------------------------------------------------------------

    The Safety Act also contains a ``make inoperative'' provision, 
which prohibits certain entities from knowingly modifying or 
deactivating any part of a device or element of design installed in or 
on a motor vehicle in compliance with an applicable FMVSS.\91\ Those 
entities include vehicle manufacturers, distributors, dealers, rental 
companies, and repair businesses. Notably, the make inoperative 
prohibition does not apply to individual vehicle owners.\92\ While 
NHTSA encourages individual vehicle owners not to degrade the safety of 
their vehicles or equipment by removing, modifying, or deactivating a 
safety system, the Safety Act does not prohibit them from doing so. 
This creates a potential source of issues for solutions that lack 
consumer acceptance, since individual owners would not be prohibited by 
Federal law from removing or modifying those systems (i.e., using 
defeat mechanisms).
---------------------------------------------------------------------------

    \91\ 49 U.S.C. 30122.
    \92\ Letter to Schaye (9/9/19) (``The ``make inoperative'' 
provision does not apply vehicle owners, and these owners are not 
precluded from modifying their vehicle by NHTSA's statutes or 
regulations. State and local laws, however, may impact whether an 
owner may use a vehicle they have modified in a particular 
jurisdiction.''), available at https://www.nhtsa.gov/interpretations/571108-ama-schaye-front-color-changing-light.
---------------------------------------------------------------------------

    Section 24220 of BIL, ``Advanced Impaired Driving Technology,'' 
\93\ directs NHTSA to issue a final rule prescribing an FMVSS ``that 
requires passenger motor vehicles manufactured after the effective date 
of that standard to be equipped with advanced drunk and impaired 
driving prevention technology.'' \94\ NHTSA is required to issue such a 
rule only if it would meet the criteria in section 30111 of the Safety 
Act.\95\ As explained above, those criteria include, among other 
things, that an FMVSS be objective, practicable, and meet the need for 
motor vehicle safety. In analyzing these criteria, NHTSA must balance 
benefits and costs and consider safety as the preeminent factor in its 
considerations.\96\
---------------------------------------------------------------------------

    \93\ Infrastructure Investment and Jobs Act, Public Law 117-58, 
section 24220 (2021).
    \94\ Section 24220(c).
    \95\ Section 24220(c), (e).
    \96\ See, e.g., Motor Vehicle Mfrs. Assn. of United States, Inc. 
v. State Farm Mut. Automobile Ins. Co., 463 U.S. 29, 55 (1983) 
(``The agency is correct to look at the costs as well as the 
benefits of Standard 208 . . . When the agency reexamines its 
findings as to the likely increase in seat belt usage, it must also 
reconsider its judgment of the reasonableness of the monetary and 
other costs associated with the standard. In reaching its judgment, 
NHTSA should bear in mind that Congress intended safety to be the 
preeminent factor under the Motor Vehicle Safety Act.'').

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

[[Page 838]]

    Section 24220 defines ``Advanced Drunk and Impaired Driving 
Technology'' as a system that
    (A) can--
    (i) passively monitor the performance of a driver of a motor 
vehicle to accurately identify whether that driver may be impaired; and
    (ii) prevent or limit motor vehicle operation if an impairment is 
detected; or
    (B) can--
    (i) passively and accurately detect whether the blood alcohol 
concentration of a driver of a motor vehicle is equal to or greater 
than the blood alcohol concentration described in section 163(a) of 
title 23, United States Code; and
    (ii) prevent or limit motor vehicle operation if a blood alcohol 
concentration above the legal limit is detected; or
    (C) is a combination of systems described in subparagraphs (A) and 
(B).\97\
---------------------------------------------------------------------------

    \97\ Section 24220(b).
---------------------------------------------------------------------------

    This means that a final rule could require vehicles be equipped 
with a system that detects whether the driver is impaired (an 
impairment-detection system); a system that detects whether the 
driver's BAC is above a specified threshold (a BAC-detection system); 
or a combination of these two systems. These options and the technology 
that might fulfill each option are discussed in greater detail later in 
this document.
    Section 24220 further requires that the ``Advanced Drunk and 
Impaired Driving Technology'' ``passively'' monitor performance or 
detect BAC. For the purposes of this advance notice of proposed 
rulemaking, NHTSA uses the term ``passive'' to mean that the system 
functions without direct action from vehicle occupants.\98\ As such, 
systems that require a ``directed breath'' towards a sensor, such as 
the current DADSS reference designs (discussed later in this document) 
or a breathalyzer that a driver must breathe into in order for the 
system to detect alcohol would not be considered ``passive'' because 
these designs require a vehicle occupant to take direct action (i.e., 
directed breath) for the system to function.
---------------------------------------------------------------------------

    \98\ FMVSS Nos. 208, ``Occupant crash protection,'' and 212, 
``Windshield mounting,'' use a similar definition for completely 
passive protection systems for occupants. 49 CFR 571.208, 571.212. 
DADSS has also viewed the term similarly. See Report to Congress on 
Progress In-Vehicle Alcohol Detection Research, October 1, 2019 
through September 30, 2020.
---------------------------------------------------------------------------

    Section 24220 does not require that a final rule give manufacturers 
the option of choosing between an impairment-detection and a BAC-
detection system. NHTSA understands the term ``impairment,'' for the 
purposes of section 24220, to refer to alcohol-related impairment as 
well as other types of driver impairment. Of course, regardless of how 
the term ``impairment'' is construed for the purposes of section 24220, 
NHTSA also has the authority under the Safety Act to issue an FMVSS 
addressing any type of driver impairment if the standard would satisfy 
the criteria in section 30111 of the Safety Act.
    The new FMVSS would be required to apply to new vehicles that carry 
12 or fewer individuals, not including motorcycles or trucks not 
designed primarily to carry its operator or passengers.\99\
---------------------------------------------------------------------------

    \99\ Section 24220 (b)(3), referring to 49 U.S.C. 32101(consumer 
information statutes).
---------------------------------------------------------------------------

    BIL also establishes a series of deadlines and requirements for 
NHTSA to report to Congress if those deadlines are not met. The 
legislation directs NHTSA to issue a final rule (if it would meet the 
section 30111 criteria) not later than November 15, 2024. If NHTSA does 
not issue a rule by this date, it must submit a report to Congress 
explaining (among other things) the reasons for not issuing a final 
rule.\100\ NHTSA must submit such reports annually until it issues a 
final rule or ten years has expired, from the date of enactment, 
whichever comes first.\101\
---------------------------------------------------------------------------

    \100\ Section 24220 (e)(2). The report must also describe the 
deployment of advanced drunk and impaired driving prevention 
technology in vehicles, any information relating to the ability of 
vehicle manufacturers to include advanced drunk and impaired driving 
prevention technology in new passenger motor vehicles, and an 
anticipated timeline for prescribing the Federal motor vehicle 
safety standard.
    \101\ Section 24220 (e)(2)-(3). If, after ten years, NHTSA has 
not promulgated the FMVSS required by this subsection, the report 
must state the reasons why the FMVSS was not finalized, the barriers 
to finalizing the FMVSS, and recommendations to Congress to 
facilitate the FMVSS.
---------------------------------------------------------------------------

III. Advanced Drunk and Impaired Driving Prevention Safety Problem

    The overall safety problem caused by various types of states of 
impaired driving is substantial, and those impaired states are part of 
the causal chain for a large percentage of crashes in the United 
States. A recent NHTSA report, ``The Economic and Societal Impact of 
Motor Vehicle Crashes (2019),'' reviewed 2019 data and described the 
state of safety prior to the COVID-19 pandemic.\102\ In 2019, the lost 
lives and costs on our society stemming from motor vehicle crashes were 
enormous--36,500 people were killed, 4.5 million people were injured, 
and the economic costs of these crashes totaled $340 billion. Of this 
$340 billion, nearly half ($167 billion) resulted from alcohol-involved 
and distracted-driving crashes alone. Furthermore, the overall safety 
problem has only gotten worse during the COVID-19 pandemic, as NHTSA 
has confirmed that the increases in fatalities, injuries, and risky 
driving that the country experienced in 2020 continued through the 
first two quarters of 2022.\103\ Recent first quarter projections for 
traffic fatalities in 2023 \104\ have reversed the trend, with NHTSA 
estimating an overall fatality decrease of about 3.3 percent as 
compared to the same time period in 2022. The second quarter of 2023 
would represent the fifth straight quarterly decline in fatalities 
after seven consecutive quarters of year-to-year increases in 
fatalities, beginning with the third quarter of 2020. Please see Graph 
2. Fatalities by Quarter \105\ below. While this is encouraging 
overall, far too many people continue to die on our roads every year, 
and drunk and impaired driving crashes still result in significant 
numbers of those lives lost.
---------------------------------------------------------------------------

    \102\ Blincoe, L., Miller, T., Wang, J.S., Swedler, D., 
Coughlin, T., Lawrence, B., Guo, F. Klauer, S., & Dingus, T. (2023, 
February). The economic and societal impact of motor vehicle 
crashes, 2019 (Revised) (Report No. DOT HS 813 403). National 
Highway Traffic Safety Administration.
    \103\ See, for example, NHTSA Estimates: Traffic Deaths Third 
Quarter of 2022 [verbar] NHTSA.
    \104\ Crash Stats: Early Estimate of Motor Vehicle Traffic 
Fatalities for the First Quarter of 2023 (dot.gov)
    \105\ NHTSA (2023). Early Estimate of Motor Vehicle Traffic 
Fatalities for the First Half (January-June) of 2023. Report No. DOT 
HS 813 514. National Highway Traffic Safety Administration: 
Washington, DC. (September)

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

[[Page 839]]

[GRAPHIC] [TIFF OMITTED] TP05JA24.002

    The introduction to this advance notice of proposed rulemaking 
states that NHTSA is considering focusing primarily on alcohol 
impairment, both because of the mandate in the BIL and because alcohol 
impairment has the tangible strategies developed to identify it. But 
the agency requests comment on this focus because of the danger that 
other impaired states cause during the driving task and because some 
options described in later sections provide the opportunity to resolve 
multiple states of impairment with the same technological solution. In 
this section, NHTSA will discuss the drunk, drowsy, and distracted 
driving states that account for most of the fatalities and crashes 
related to impaired driving. NHTSA has presented the safety problem in 
this way because the agency is interested in proceeding with whatever 
practical course of action results in the most lives saved and injuries 
prevented in the shortest amount of time, regardless of what impaired 
driving state is the root cause. Additionally, NHTSA believes the 
public should be aware of the overall safety problem associated with 
driver impairment so that it may have adequate information when 
responding to NHTSA's questions about whether focusing on alcohol-
impairment is the best path forward to achieve improved motor vehicle 
safety and protect the public from the complex behavioral issues that 
result in driver impairment.
    For this analysis, we consider the three categories of impaired 
driving safety impacts most likely to be ameliorated by a safety 
countermeasure arising from this ANPRM: drunk driving, drowsy driving, 
and distracted driving. As mentioned in the introduction, NHTSA hopes 
that the agency's approach may yield additional safety benefits by 
considering all technologies that have the potential to mitigate or 
prevent impaired driving fatalities and injuries.
    The safety data on drunk driving, and the confidence in those data, 
are much more substantial than data on other types of impaired driving, 
and drunk driving results in serious loss of life, injury, and economic 
costs to the public. This section will present estimates of annual 
fatalities and injuries due to drunk, drowsy, and distracted driving.
    It is also worth noting that in other recent rulemakings, NHTSA 
decided not to use post-2019 data because the agency was not yet sure 
whether the disturbing uptick in crashes and fatalities was an anomaly 
or a trend that reflects a change in vehicle safety that would remain 
for more than one year or the foreseeable future. Analysis since the 
issuance of previous documents indicates that data from 2020 and 2021 
highlight a potentially dangerous trend in the United States of an 
increase in motor vehicle crashes and fatalities, which is why this 
advance notice of proposed rulemaking differs from other documents 
issued in the recent past in citing post-2019 data.

A. Drunk Driving

    Per FARS, in 2021 there were 13,384 traffic fatalities in which at 
least one driver had a BAC at or above .08 g/dL, (representing 
approximately 31 percent of all traffic fatalities in the United 
States). NHTSA's process for identifying fatalities due to drunk 
driving begins by acknowledging that not all alcohol-related motor 
vehicle fatalities and injuries are caused by alcohol consumption. In 
NHTSA's fatality numbers reported in FARS, use of the term ``alcohol-
impaired'' does not indicate that a crash or a fatality was caused by 
alcohol impairment, only that an alcohol-impaired driver was involved 
in the crash. That is, some of the crashes may have involved causative 
factors other than alcohol (e.g., one or multiple drivers or vehicles 
associated with speeding, reckless behavior, or mechanical failure).
    Critically for this advance notice of proposed rulemaking, NHTSA's 
analysis has applied Blomberg et al.'s risk factors to estimate that 
alcohol is indeed a causal factor in 94 percent of crashes involving at 
least one driver with a BAC at or above .08 g/dL.\106\ Thus, the agency 
estimates that, among all crashes, fatalities, and injuries involving 
drivers that have a BAC at or above .08 g/dL, 94 percent of them are 
due directly to

[[Page 840]]

alcohol consumption and are thus within the scope of impaired driving 
countermeasures that would focus on the legal limit in most States (.08 
g/dL). This yields an estimate of approximately 12,581 fatalities in 
2021 due to alcohol impairment. At an estimated comprehensive economic 
cost of approximately $12.7 million per fatality (adjusted to 2022 
dollars using the GDP Implicit Price Deflator 107 108), 
fatalities in alcohol impairment-related crashes were associated with 
societal safety costs of approximately $160 billion in 2021.
---------------------------------------------------------------------------

    \106\ Blincoe et al., 2023 Blomberg, R., Peck, R.C., Moskowitz, 
H., Burns, M., & Fiorentino, D. (2005, September). Crash risk of 
alcohol-involved driving: A case-control study. Dunlap and 
Associates; Blincoe et al., 2023.
    \107\ Blincoe et al., 2023.
    \108\ https://fred.stlouisfed.org/series/USAGDPDEFAISMEI.
---------------------------------------------------------------------------

B. Distracted Driving

    Historically, distracted driving crashes have been more difficult 
to quantify than drunk driving crashes because unlike BAC, distraction 
cannot yet be tested for objectively post-crash. However, Blincoe et 
al. developed and implemented a methodology to estimate both: (1) 
underreporting of cases involving distraction; and (2) the shares of 
crashes, fatalities, and injuries caused by distraction.\109\ NHTSA 
applies the results of Blincoe et al. here to 2021 FARS data to 
estimate fatalities in 2021 due to distracted driving.
---------------------------------------------------------------------------

    \109\ Blincoe et al., 2023.
---------------------------------------------------------------------------

    Blincoe et al. estimate that 28.9 percent of all crashes (and 
injuries of all severities within crashes) are due to distraction. 
Based on this estimate, the agency estimates that distracted driving 
caused 12,405 fatalities in 2021. This represents a societal safety 
cost of approximately $158 billion, an economic estimate of the loss of 
life.
    Dingus et al. report that approximately seven percent of cases of 
distraction also involve some form of impairment. In turn, it is 
appropriate to assume that there is at least some degree of overlap 
among drunk driving and distracted driving fatalities. Thus, the 
combined safety problem associated with drunk driving and distracted 
driving is likely to be somewhat smaller than the sum of the individual 
estimates above (i.e., distracted driving fatalities in 2021 not 
jointly caused by alcohol would be up to 7% lower than the estimate of 
12,405 fatalities above).

C. Drowsy Driving

    Drowsy driving is more difficult to quantify than drunk driving 
because, among other factors, there is not currently an accepted 
standard definition of drowsiness in a driving context, nor a threshold 
to define drowsiness as a causal factor in motor vehicle crashes. In 
turn, the level of drowsiness-related crashes and injuries is subject 
to faulty measurement, with underreporting more likely than 
overreporting. In defining the drowsy driving safety problem, NHTSA 
begins with estimates based on police-reported drowsiness as a 
contributing factor, and then considers external estimates of 
underreporting.
    To estimate fatalities in 2021 associated with drowsy driving, the 
agency analyzes fatalities reported in FARS in which at least one 
driver was reported as asleep or drowsy: this revealed 684 fatalities, 
or approximately 1.6 percent of total annual fatalities.
    Applying estimates of the comprehensive economic costs of injury 
from the last section, NHTSA estimates that reported fatalities 
associated with drowsy driving in 2021 represent a social cost of 
approximately $9 billion.
    NHTSA's annual estimates of fatalities associated with drowsy 
driving are consistent with other NHTSA estimates (e.g., annual 
drowsiness-related fatality estimates in NHTSA's ``Drowsy Driving 
2015'').110 111 However, the estimates are lower than other 
external estimates, such as Tefft, which estimates that one-sixth of 
traffic fatalities are associated with drowsiness,\112\ and Owens et. 
al which estimates that approximately one-tenth of police-reportable 
crashes are associated with drowsiness.\113\ NHTSA does not have 
sufficient evidence regarding underreporting. On the other hand, 
consistent with the discussion of drowsiness-related crashes and 
acknowledges that underreporting distracted driving above, it is a 
feasible constraint to estimating the scale of the that at least some 
fatalities caused by drowsy driving safety problem. are also caused by 
alcohol impairment or distraction (furthermore, the drowsiness itself 
could be caused by drinking, and the distraction itself could be caused 
by drowsiness). For this analysis, the agency applies its estimate as a 
conservative estimate of a significant safety issue (i.e., NHTSA 
expects the true annual safety costs associated with drowsy driving to 
be at least as large as estimated here). The agency requests comment 
and data regarding underreporting of drowsy driving, and 
interdependencies among drunk driving, distracted driving, and drowsy 
driving.
---------------------------------------------------------------------------

    \110\ National Center for Statistics and Analysis. (2017 
October). Drowsy Driving 2015 (CrashStats Brief Statistical Summary. 
Report No. DOT HS 812 446). Washington, DC: National Highway Traffic 
Safety Administration.
    \111\ Knipling, R. & Wang, J. (1994). Crashes and fatalities 
related to driver drowsiness/fatigue. Washington, DC: National 
Highway Traffic Safety Administration.
    \112\ Tefft, B. (2010). The Prevalence and Impact of Drowsy 
Driving (Technical Report). Washington, DC: AAA Foundation for 
Traffic Safety.
    \113\ Owens, J.M., Dingus, T.A.. Guo, F., Fang, Y., Perez, M., 
McClafferty, J., & Tefft, B.C. (2018). Prevalence of Drowsy Driving 
Crashes: Estimates from a Large-Scale Naturalistic Driving Study 
(Research Brief). Washington, DC: AAA Foundation for Traffic Safety.
---------------------------------------------------------------------------

IV. Overview of Current Efforts To Address Drunk and Impaired Driving

    NHTSA has a robust portfolio of behavioral-prevention and vehicle-
research activities focused on preventing drunk and impaired driving. 
NHTSA believes that the combination of these strategies (i.e., 
behavioral strategies and vehicle-based countermeasures) is necessary 
to move towards a nation where alcohol-impaired individuals are unable 
to drive vehicles and put the lives of everyone around them at risk by 
doing so. As discussed in the introduction, one of the effects that 
leads drivers to take such unacceptable risks when intoxicated is 
alcohol's impact on their brain, especially in impairing judgment.

A. State and Federal Behavioral Prevention Activities

    Behavioral prevention activities are public-oriented strategies 
intended to change the behaviors that lead to drunk and impaired 
driving. This is distinguished from vehicle-based countermeasures, 
which are discussed later in this document. To develop and implement 
these behavioral strategies, NHTSA collaborates with a wide array of 
national, regional, State, and local traffic safety partners, including 
those in the following sectors: public safety and criminal justice; 
medical, public health and emergency services; educators; parents; non-
profits; traffic safety organizations; and academic institutions. More 
recently, NHTSA has expanded these partnerships to include substance 
use prevention, mental health, and overall wellness efforts as part an 
overall approach to address issues that lead to drunk and impaired 
driving.
    NHTSA's behavioral prevention activities can be categorized into 
three main areas. First, NHTSA conducts research to identify the scope 
of the issue and develop effective evidence-based strategies to address 
the behaviors that lead to drunk and impaired driving. Second, NHTSA 
distributes Federal grant funds to individual States, and these funds 
are used for behavioral strategies.\114\ Each State is required to

[[Page 841]]

have a highway safety program, approved by the Secretary of 
Transportation, that is designed to reduce traffic crashes and the 
resulting deaths, injuries, and property damage. NHTSA provides grants 
to each State for their highway safety program as well as funds to 
address national priorities for reducing highway deaths and injuries, 
such as impaired driving programs. Third, NHTSA works directly with 
States and other stakeholders to develop, implement, and support 
effective programs and strategies to stop drunk and impaired driving. 
This includes demonstration projects, training and education for 
traffic safety professionals, and communications campaigns to educate 
the public. NHTSA also helps States use data to identify their highway 
safety needs and evaluate safety programs and activities, and the 
agency provides technical assistance and training to State program 
managers.
---------------------------------------------------------------------------

    \114\ See, e.g., 23 U.S.C. 402 (fund that can be used for any 
purpose); 23 U.S.C. 405(d) (priority funds, specifically for 
impaired driving); 23 U.S.C. 154 (open container); 23 U.S.C. 164 
(repeat offender).
---------------------------------------------------------------------------

    Below we briefly discuss four of the main drunk and impaired 
driving behavioral strategies that help us execute our three main areas 
mentioned above: Deterrence; Prevention; Communications and outreach; 
and alcohol and drug treatment programs.\115\
---------------------------------------------------------------------------

    \115\ See Venkatraman, V., Richard, C.M., Magee, K., & Johnson, 
K. (2021, July). Countermeasures that work: A highway safety 
countermeasures guide for State Highway Safety Offices, 10th 
edition, 2020 (Report No. DOT HS 813 097). National Highway Traffic 
Safety Administration. (hereinafter Countermeasures that work). 
Vehicle and infrastructure strategies can also reduce the likelihood 
of crashes and/or injuries sustained by impaired drivers and 
passengers, such as improved vehicle structures and centerline 
rumble strips and barriers. These countermeasures are outside the 
scope of this discussion.
---------------------------------------------------------------------------

1. Deterrence
    Deterrence includes enacting laws that prohibit drunk and impaired 
driving, publicizing and enforcing those laws, and identifying and 
punishing offenders.\116\ Deterrence works by changing a driver's 
behavior through concern for the consequences of certain behaviors, 
such as being apprehended by law enforcement. Below we provide a brief 
overview of activities in these areas with respect to drunk and 
impaired driving, with a focus on State and Federal drunk driving laws 
and NHTSA's efforts to support and develop training and best practices 
for law enforcement, prosecutors, judges, and other public safety and 
criminal justice partners.
---------------------------------------------------------------------------

    \116\ Venkatraman, V., Richard, C.M., Magee, K., & Johnson, K. 
(2021, July). Countermeasures that work: A highway safety 
countermeasures guide for State Highway Safety Offices, 10th 
edition, 2020 (Report No. DOT HS 813 097). National Highway Traffic 
Safety Administration.
---------------------------------------------------------------------------

a. State and Federal Drunk Driving Laws
    State laws, as well as Federal law governing the use of motor 
vehicles on Federally owned land, prohibit operation of a motor vehicle 
when the driver is at or exceeds the state's per se illegal limit 
(i.e., BAC of .08 g/dL in all states, except Utah which has a .05 g/dL 
illegal limit).
    All States have enacted drunk driving laws. Some of these laws have 
been incentivized by Federal law, because significant portions of the 
Federal funds available to the States, including State Highway funds, 
are conditioned on a State enacting and enforcing specific laws related 
to drunk driving. This includes laws prohibiting operation of a motor 
vehicle with a BAC of .08 percent or greater; \117\ laws prohibiting 
individuals under the age of 21 from operating a motor vehicle with a 
BAC of .02 percent or greater (zero-tolerance laws); \118\ laws setting 
a minimum drinking age of 21; \119\ and laws prohibiting possession of 
open alcohol beverage containers and consumption of alcohol in a 
vehicle (open-container laws).\120\ If a State does not have the 
required laws, it loses significant funding to which it would otherwise 
be entitled. Accordingly, all States have enacted such laws.\121\ Many 
States have also gone above and beyond the Federally-incentivized laws. 
For instance, on December 30, 2018, Utah lowered its BAC threshold to 
.05 g/dL for all drivers. Examples of other laws States have enacted 
include driver license revocation or suspension if drivers fail or 
refuse to take BAC tests, and increased penalties for repeat offenders 
or for offenders with higher BACs.
---------------------------------------------------------------------------

    \117\ 23 U.S.C. 163.
    \118\ 23 U.S.C. 161.
    \119\ 23 U.S.C. 158.
    \120\ 23 U.S.C. 154.
    \121\ See https://www.ghsa.org/state-laws/issues/alcohol%20impaired%20driving (last accessed January 5, 2023); 
https://www.ncsl.org/research/transportation/drunken-driving.aspx 
(last accessed January 5, 2023).
---------------------------------------------------------------------------

    The National Transportation Safety Board (NTSB) has recently 
recommended that NHTSA seek legislative authority to award incentive 
grants for States to establish a per se BAC limit of .05 or lower for 
all drivers who are not already required to adhere to lower BAC 
limits.\122\ In response to this recommendation, NHTSA published the 
results of preliminary research on the effects of Utah's law.\123\ This 
research suggests that the .05 g/dL per se law has had quantifiable 
positive impacts on highway safety in Utah so that lower BAC thresholds 
may be effective in further reducing alcohol-involved crashes. In 
addition to these State laws, Federal regulations prohibit drunk 
driving on Federal lands.\124\ An individual may not operate a motor 
vehicle on Federal land if they are unable to safely operate the 
vehicle due to the influence of alcohol or other drugs, or if their BAC 
is .08 g/dL or greater.\125\ The law also authorizes testing of three 
bodily fluids: blood, saliva, and urine. It includes stipulations 
around proper administration of accepted scientific methods and 
equipment used by certified personnel, noting that for blood sample 
testing, there are further restrictions whereby normally a search 
warrant is required from an authorized individual.
---------------------------------------------------------------------------

    \122\ https://www.ntsb.gov/safety/safety-studies/Documents/SR1301.pdf.
    \123\ Thomas, F.D., Blomberg R., Darrah, J., Graham, L., 
Southcott, T., Dennert, R., Taylor, E., Treffers, R., Tippetts, S., 
McKnight, S., & Berning, A. (2022, February). Evaluation of Utah's 
.05 BAC per se law. DOT HS 813 233. NHTSA.
    \124\ 36 CFR 4.23.
    \125\ If State law establishes more restrictive BAC limits, 
those more restrictive limits supersede the .08 g/dL limit specified 
in the Federal regulations.
---------------------------------------------------------------------------

b. Training and Best Practices for Law Enforcement, Prosecutors, 
Judges, and Other Public Safety and Criminal Justice Partners
    NHTSA actively supports efforts to develop training and best 
practices for law enforcement, prosecutors, judges, and other public 
safety and criminal justice partners regarding the detection, 
prosecution, and adjudication of drunk and impaired driving. A brief 
sampling of NHTSA's work in this area includes the following:
    Development and application of field sobriety tests. In the mid-
1970s NHTSA, with the cooperation and assistance of the law enforcement 
community, conducted research that resulted in a standardized battery 
of three field sobriety tests (the horizontal gaze nystagmus test; the 
walk-and-turn test; and the one-leg stand test). Police officers use 
these tests to help establish probable cause for a driving while 
intoxicated (DWI \126\) arrest.
---------------------------------------------------------------------------

    \126\ DWI and DUI are used interchangeably throughout this 
document.
---------------------------------------------------------------------------

    Standards for alcohol breath-test devices. Evidential breath test 
devices conform to established specifications and can be used as 
evidence in court. NHTSA publishes standard specifications for 
evidential breath-test devices, and a ``Conforming Products List'' of 
alcohol testing and screening

[[Page 842]]

devices.\127\ Law enforcement officers use the totality of the evidence 
in determining whether sufficient probable cause exists to effectuate 
an arrest for drunk driving. This includes observation of the vehicle 
in motion, results of the standardized field sobriety tests, and other 
information to establish probable cause. An officer may use a 
preliminary or evidential breath test device to measure BrAC. A suspect 
may also be requested to provide a blood or urine sample.
---------------------------------------------------------------------------

    \127\ Federal Register/Vol. 58, No. 179/pp 48705-48710/Friday, 
September 17,1993/Notices (58 FR 48705) Federal Register/Vol. 77, 
No. 115/pp 35745-35750/Thursday, June 14, 2012/Notices (77 FR 35745, 
77 FR 35747).
---------------------------------------------------------------------------

    Arrest and crash reporting. NHTSA provides training on arrest and 
crash reporting to law enforcement so that the data collected during a 
traffic stop or arrest, or at the scene of a crash, is uniform, clear, 
and concise.
    Training curriculum development for law enforcement, prosecutors, 
judges, and other public safety and criminal justice partners. Through 
cooperative agreements and partnerships, NHTSA supports training for 
law enforcement, prosecutors, judges, and other public safety and 
criminal justice partners.
    For example, NHTSA provides (through a cooperative agreement with 
the International Association of Chiefs of Police) funding for 
curricula development and management of programs developed to train law 
enforcement in detecting, investigating, and apprehending impaired 
drivers. NHTSA also provides the law enforcement community with 
resources to carry out local DWI programs, such as supplying laminated 
pocket guides for the standard field sobriety tests to aid officers. 
Through partnerships with national law enforcement organizations such 
as the National Criminal Justice Training Center, NHTSA maintains a 
wide reach when providing these resources.
    NHTSA also helps ensure that organizations representing 
prosecutors, judges, and pretrial, parole, supervision, and probation 
officers have accurate and up-to-date information about the harm caused 
by impaired driving, the crash risk of various impairing substances, 
and evidence-based sanction and treatment options. For example, NHTSA 
has cooperative agreements with the National Traffic Law Center and the 
National Association of Prosecutor Coordinators to develop curricula 
and provide training to prosecutors working on impaired driving cases. 
Through these agreements, NHTSA provides prosecutors with information 
on relevant case law, monographs on various legal issues, an expert 
witness database, training courses, and peer-to-peer support from 
Traffic Safety Resource Prosecutors (TSRP) in each State. The TSRP 
Program trains current and former prosecutors to become instructors for 
traffic crimes prosecutors and law enforcement personnel.\128\ This 
facilitates a coordinated, multidisciplinary approach to the 
prosecution of drunk and impaired driving. NHTSA also funds training 
through the National Judicial College on (among other things) evidence-
based sentencing and supervision practices, toxicology, the use of 
ignition interlocks, and DWI Courts. NHTSA also funds the American Bar 
Association to conduct the Judicial Outreach Liaison program providing 
trial judges with current evidence-based practices, peer-to-peer 
judicial education, a liaison to the broader highway safety community.
---------------------------------------------------------------------------

    \128\ https://www.nhtsa.gov/sites/nhtsa.gov/files/documents/12323_tsrpmanual_092216_v3-tag.pdf.
---------------------------------------------------------------------------

    Based on these models, NHTSA is also piloting similar education 
programs for pretrial, probation, parole, and supervision professionals 
\129\ and toxicologists.
---------------------------------------------------------------------------

    \129\ https://www.appa-net.org/idarc/training-faculty.html.
---------------------------------------------------------------------------

2. Prevention
    Prevention strategies reduce impaired driving by reducing use of 
impairing substances or preventing driving by people who have been 
drinking or using other drugs. There are a variety of prevention 
countermeasures. Below we discuss the main ones.
a. Alcohol Ignition Interlocks
    One impaired driving prevention strategy is requiring the 
installation of alcohol ignition interlocks. Ignition interlocks are 
devices that measure the driver's BrAC and prevent the vehicle from 
starting if it exceeds a pre-set level (usually .02 g/dL). Interlocks 
are highly effective in allowing vehicles to be started by sober 
drivers, but not by alcohol-impaired drivers. Alcohol ignition 
interlocks are typically used as a condition of probation for DWI 
offenders after their driver's licenses have been reinstated. Forty-
four States require the devices for repeat, high-BAC, or all 
offenders.\130\
---------------------------------------------------------------------------

    \130\ https://www.ncsl.org/research/transportation/state-ignition-interlock-laws.aspx.
---------------------------------------------------------------------------

    There is evidence that requiring interlocks for driving under the 
influence (DUI) offenders helps reduce recidivism. NHTSA evaluated the 
New Mexico Ignition Interlock program in 2010 \131\ and found that 
alcohol-sensing technology in vehicles can be successfully deployed to 
protect the public from alcohol-impaired drivers and that recidivism 
rates can be reduced if penetration of these devices is sufficient. In 
2015, NHTSA reported on interlock use in 28 States.\132\ This 2015 
report identified important program elements for States to achieve and 
sustain high interlock use rates including: strong interlock 
requirements and incentives coupled with effective penalties for non-
compliance; strong program management involving monitoring, uniformity, 
coordination, and education; and data and resources to support program 
management and to evaluate changes in program design.
---------------------------------------------------------------------------

    \131\ Evaluation of the New Mexico Ignition Interlock Program 
(2010). DOT HS 811 410.
    \132\ Evaluation of State Ignition Interlock Programs: Interlock 
Use Analyses from 28 States, 2006-2011 (2015) DOT HS 812 145.
---------------------------------------------------------------------------

    A more recent study found that laws mandating alcohol ignition 
interlocks, especially those covering all offenders, are an effective 
alcohol-impaired driving countermeasure that reduces the number of 
alcohol-impaired drivers in fatal crashes.\133\
---------------------------------------------------------------------------

    \133\ Teoh, Eric R./Fell, James C./Scherer, Michael/Wolfe, 
Danielle E.R., State alcohol ignition interlock laws and fatal 
crashes, Traffic Injury Prevention (TIP), October 2021.
---------------------------------------------------------------------------

    NHTSA has also conducted research, developed model specifications, 
and provided information and funding to improve State ignition 
interlock programs. NHTSA research on ignition interlocks dates back to 
early studies on the increased likelihood for DWI offenders to be 
involved in fatal crashes while intoxicated.\134\ Based on research 
that license suspension alone did not keep DWI offenders from driving, 
NHTSA conducted research into performance-based interlocks that could 
prevent a drunk driver from starting the vehicle.\135\ NHTSA also 
drafted and revised model specifications for interlock devices. These 
specifications have developed over time and are published in the 
Federal Register as guidelines for State interlock programs.\136\ NHTSA 
has published an

[[Page 843]]

ignition interlock toolkit,\137\ a program guide on key features for 
ignition interlock programs,\138\ and various case studies and 
evaluation reports.\139\ NHTSA continues to fund the Association of 
Ignition Interlock Program Administrators.\140\
---------------------------------------------------------------------------

    \134\ Hedlund, J., & Fell, J. (1995). Persistent drinking 
drivers in the U.S., 39th Annual Proceedings of the Association for 
the Advancement of Automotive Medicine, October 16-18, 1995, 
Chicago, IL (pp. 1-12). Des Plaines, IL: Association for the 
Advancement of Automotive Medicine.
    \135\ This research also considered impairment including drugs 
and drowsiness.
    \136\ 78 FR 26849 (May 8, 2013), available at https://www.volpe.dot.gov/sites/volpe.dot.gov/files/docs/Breath%20Alcohol%20Ignition%20Interlock%20Device%20%28BAIID%29%20Model%20Specifications.pdf.
    \137\ https://www.nhtsa.gov/sites/nhtsa.gov/files/documents/ignitioninterlocks_811883_112619.pdf. This is a toolkit for 
policymakers, highway safety professionals and advocates that brings 
together resources that explain and support the use of alcohol 
ignition interlocks, identifies issues faced by ignition interlock 
programs and includes information on the use of interlocks in each 
State and the District of Columbia. It is designed to advance the 
understanding of ignition interlock technology, improving its 
application as an effective strategy to save lives and prevent 
impaired driving injuries.
    \138\ https://www.nhtsa.gov/sites/nhtsa.gov/files/811262.pdf.
    \139\ See, e.g., https://rosap.ntl.bts.gov/view/dot/1909.
    \140\ https://aiipaonline.org/.
---------------------------------------------------------------------------

    As discussed later in greater detail, since 2008 NHTSA has 
participated in and helped fund a cooperative research program, known 
as DADSS, which is developing next-generation vehicle alcohol detection 
technologies.
b. Designated Driver and Alternative Transportation Programs
    NHTSA also supports designated driver and alternative 
transportation programs as another avenue for preventing impaired 
driving.
    Designated driver programs encourage drinkers to include someone in 
their party who does not drink and will be able to provide a safe ride 
home. Some designated-driver programs provide incentives such as free 
soft drinks for designated drivers. Mass-media campaigns--such as the 
NHTSA-sponsored Ad Council campaign ``Friends Don't Let Friends Drive 
Drunk''--seek to raise awareness and promote the use of these programs.
    Alternative transportation programs offer methods people can use to 
get to and from places where they drink without having to drive. This 
includes public transportation (such as subways and buses) as well as 
for-profit and nonprofit ``safe rides.'' For-profit safe rides include 
transportation network companies that are on-demand and may be accessed 
through a mobile application. Nonprofit safe-ride programs are free to 
patrons or charge minimal fees and often operate in specific regions or 
at specific times such as weekends and holidays when impaired crashes 
occur at higher rates. Several States fund alternative transportation 
as part of their impaired driving prevention efforts.
c. Alcohol Sales and Service Regulations/Programs
    Another common strategy to prevent impaired driving are regulations 
and programs that target the point at which alcoholic beverages are 
sold. Responsible beverage service programs cover alcohol sales 
policies and practices that prevent or discourage restaurant or bar 
patrons from drinking excessively or from driving while impaired by 
alcohol. NHTSA supports server training programs to teach servers how 
to recognize the signs of intoxication, how to prevent intoxicated 
patrons from further drinking and from driving, as well as bar and 
restaurant management policies to reduce impaired driving.
d. Underage Impaired Driving Prevention
    One particular focus of prevention strategies is preventing 
underage impaired driving. Teenagers drink and drive less often than 
adults but are more likely to crash when they do drink and drive.\141\ 
While many of the prevention strategies discussed above apply both to 
adults and teenagers, NHTSA supports several prevention strategies 
directed specifically to those under the age of 21. NHTSA publishes 
fact sheets,\142\ research, and funded program guides \143\ on teen 
traffic safety and effective practices to reduce teen impaired driving. 
NHTSA also partners with youth advocacy organizations as well as 
primary and secondary education organizations to provide youth-focused 
impaired driving prevention education, messages, teacher resources, and 
educational materials for drivers of all ages. Furthermore, NHTSA 
partners with driver educators to teach teen and novice drivers about 
the dangers of impaired driving and to develop driver education 
standards.
---------------------------------------------------------------------------

    \141\ Bingham CR, Shope JT, Parow JE, Raghunathan TE. Crash 
types: markers of increased risk of alcohol-involved crashes among 
teen drivers. J Stud Alcohol Drugs. 2009 Jul;70(4):528-35. doi: 
10.15288/jsad.2009.70.528. PMID: 19515292; PMCID: PMC2696293.
    \142\ https://crashstats.nhtsa.dot.gov/Api/Public/ViewPublication/813313.
    \143\ See e.g., https://www.ghsa.org/resources/Peer-to-Peer19.
---------------------------------------------------------------------------

3. Communications Campaigns
    Public service messaging and coordinated enforcement are also 
important behavioral strategies. Communications campaigns inform the 
public of the dangers of impaired driving and promote positive social 
norms of not driving while impaired. NHTSA coordinates with States and 
other traffic safety stakeholders to educate the public about the 
impairing effects of alcohol and drugs and the dangers they pose to 
drivers of all ages. NHTSA produces a communications calendar annually 
with details about specific campaign and enforcement periods, holidays, 
and other notable events during which time there may be increased 
dissemination of campaign messages and coordinated law enforcement 
efforts at the State and local level. Campaign materials are made 
accessible to the public and stakeholders online at Traffic Safety 
Marketing (TSM).\144\ These communications efforts can be divided into 
two categories: high-visibility enforcement and social norming 
campaigns.
---------------------------------------------------------------------------

    \144\ https://www.trafficsafetymarketing.gov/.
---------------------------------------------------------------------------

a. High-Visibility Enforcement Campaigns
    High-visibility enforcement campaigns coordinate highly visible and 
proactive law enforcement activities with public service messages 
highlighting the dangers of impaired driving and the enhanced 
enforcement efforts. NHTSA runs two national high-visibility impaired 
driving campaigns each year--one in August, leading up to and including 
Labor Day weekend, and one in December, during the winter holiday 
period. High-visibility enforcement campaigns include national media 
segments that air on TV and radio as well as digital media in English 
and Spanish. Both campaigns include national paid media buys 
incorporating both an alcohol-impaired driving message (Drive Sober or 
Get Pulled Over) and a drug-impaired driving message (If You Feel 
Different, You Drive Different. Drive High, Get a DUI). These campaign 
assets are available at no cost for States, regions, and other 
stakeholders to download and use during applicable campaign periods. 
During each campaign timeframe, NHTSA encourages law enforcement and 
other State agencies to use the provided assets on social media. State 
leaders can also engage with the local news media to expand awareness 
of the campaigns and associated messages. Each campaign period comes 
with information on how to conduct Media Buys, and its reports on the 
number of impressions made.
b. Social-Norming Campaigns
    Communications efforts are not limited to high-visibility 
enforcement campaigns but also continue throughout the year. For 
instance, NHTSA has public service announcement campaigns that rely on 
donated time

[[Page 844]]

and space from various media outlets throughout the nation. The main 
message for alcohol-impaired driving is ``Buzzed Driving is Drunk 
Driving,'' and the main message for drug-impaired driving is ``If you 
Feel Different, You Drive Different.'' NHTSA works with the Ad Council 
to produce campaign resources (TV, radio, digital, print, and outdoor 
advertising) and distributes them to organizations that donate time and 
space to support campaign messaging.
4. Alcohol and Drug Treatment, Monitoring, and Control
    Treatment for substance use is another major strategy to address 
the behaviors leading to drunk and impaired driving. It is widely 
recognized that many DWI first offenders and most repeat offenders meet 
criteria for an alcohol use disorder and are likely to continue to 
drink and drive unless the underlying substance use disorder is 
addressed. DWI arrests provide an opportunity to identify offenders 
with alcohol use problems, and as part of a plea bargain or diversion 
program, refer them to treatment in addition to imposing sanctions.
    NHTSA endorses the use of the Substance Abuse and Mental Health 
Services Administration's Screening, Brief Intervention and Referral to 
Treatment (SBIRT) approach. This is a comprehensive, integrated, public 
health approach to the delivery of early intervention and treatment 
services for persons with substance use disorders, as well as those who 
are at risk of developing these disorders.\145\ To help States use an 
SBIRT approach NHTSA funded the American Probation and Parole 
Association to develop the Impaired Driving Assessment. This tool 
provides a framework for screening impaired drivers, estimating their 
risk for future impaired driving, and assessing responsivity to 
intervention efforts, among other things.
---------------------------------------------------------------------------

    \145\ https://www.samhsa.gov/sbirt.
---------------------------------------------------------------------------

    NHTSA also encourages States and jurisdictions to establish DWI 
courts. DWI courts are specialized, comprehensive programs providing 
treatment, supervision, and accountability for repeat DWI offenders. 
These courts follow the well-established drug court model and are 
usually aimed at drivers with prior DWI offenses or those with BACs of 
.15 g/dL or higher. In 2019, NHTSA entered into a cooperative agreement 
with the National Center for DWI Courts to develop the 10 Guiding 
Principles for DWI Courts document, provide education and training for 
both new and existing DWI Courts, fund technology for the expansion of 
reach to underserved populations, and fund services (e.g., treatment) 
to high-risk/high-need offenders.\146\ There is evidence that DWI 
courts have greater success in changing driver behavior compared to 
traditional court processes and sanctions. A 2011 evaluation by NHTSA 
of three Georgia DUI Courts found substantial reductions in recidivism 
for repeat DUI offenders.\147\
---------------------------------------------------------------------------

    \146\ https://rosap.ntl.bts.gov/view/dot/2055.
    \147\ https://rosap.ntl.bts.gov/view/dot/2055.
---------------------------------------------------------------------------

B. Vehicle-Based Countermeasures

    While the previous section discussed the various behavioral efforts 
that NHTSA has engaged in, NHTSA is conducting complementary research 
on vehicle safety technologies that have the potential to prevent or 
mitigate drunk and impaired driving. The behavioral campaigns and the 
vehicle-based countermeasures are part of NHTSA's dynamic strategy to 
achieve zero fatalities related to driver impairment.
1. Summary of Research on Vehicle-Based Countermeasures
    This section summarizes five major research efforts focused on 
vehicle safety technologies: (1) Driver Alcohol Detection System for 
Safety, (2) Driver Monitoring of Inattention and Impairment Using 
Vehicle Equipment, (3) NHTSA's Request for Information, (4) Technology 
Scans, and (5) Additional ongoing research.
a. Driver Alcohol Detection System for Safety
    NHTSA has been conducting research to understand ways to detect 
driver impairment. A major research program is DADSS. NHTSA began the 
DADSS Program in 2008 through a Cooperative Agreement between the 
Agency and the Automotive Coalition for Traffic Safety (ACTS) to 
develop non-invasive technology to prevent alcohol-impaired driving by 
measuring blood or breath alcohol accurately, precisely, and rapidly. 
Exploratory research in early phases of the program established the 
feasibility of two sensor approaches for in-vehicle use: breath- and 
touch-based. Since then, there have been significant advances in sensor 
hardware and software development, as the program works toward meeting 
high-performance standards required for passive, accurate, and reliable 
alcohol measurement.
    There are two technology approaches under development for DADSS, 
and both use infrared spectroscopy to measure a driver's alcohol 
concentration. The DADSS touch sensor measures the BAC in the capillary 
blood in the dermis layer of the skin on the palmar side of a driver's 
hand. A touch pad with an optical module could be integrated into an 
ignition switch or steering wheel. When the driver touches the steering 
wheel or ignition switch, a near infrared light shines into the 
driver's skin. The portion of the near infrared light that is reflected 
back is collected by the touch pad. This light transmits information 
about the skin's chemical properties, including the concentration of 
alcohol present. The DADSS breath sensor uses detectors that 
simultaneously measure the concentrations of alcohol and carbon dioxide 
(CO2) in a driver's exhaled breath.\148\ The diluted breath 
is drawn into a measurement cavity where optical detectors measure the 
amount of infrared light absorbed by the alcohol and CO2. 
Using these measurements, the driver's BrAC is calculated.
---------------------------------------------------------------------------

    \148\ The concentration of CO2 in the breath provides 
an indication of the degree of dilution of the alcohol concentration 
indicating the distance from the sensor the breath was exhaled to 
determine if the sample is from the driver.
---------------------------------------------------------------------------

    It is worth emphasizing that the current DADSS breath sensor 
requires directed puff of breath toward the sensor and would therefore 
not be considered passive under BIL. The end design that the DADSS 
program is working toward is a breath sensor that will capture 
naturally exhaled breath to make the calculation and may be considered 
passive as required by the BIL. The goal is not to require the driver 
to actively blow or puff air or take other action to provide the 
requisite sample for the system to analyze. The DADSS touch sensor is 
being designed to be embedded in something that the driver must touch 
to operate the vehicle, for example, push-to-start button, the steering 
wheel, or the gear shift selector. Therefore, NHTSA tentatively 
determines that such a touch sensor could be considered passive.
    As part of the cooperative agreement with NHTSA, ACTS is planning 
to develop DADSS Reference Designs for the sensors that include 
schematics, specifications, minimum hardware requirements, and other 
documentation for the DADSS sensors so the technology can be licensed, 
and sensors manufactured. ACTS plans for open licensing of the sensors, 
which means the technology will be made available on the same terms to 
any automaker or supplier interested in installing the technology into 
their vehicles or products. The first DADSS Reference Design--a 
directed-breath, zero-tolerance (BrAC >.02 g/dL) accessory

[[Page 845]]

system for limited deployment in fleet vehicles--was released for open 
licensing in December 2021. A second DADSS zero-tolerance touch system 
reference design intended for fleet vehicles is expected in 2024, 
according to ACTS. ACTS expects touch and breath sensor reference 
designs for private vehicles, capable of higher BAC measurements, in 
2025.\149\ NHTSA is aware that these delivery dates may be affected by 
several factors including further research and development and 
continued supply-chain issues resulting from the COVID-19 pandemic. 
These dates do not include the time necessary for any manufacturer to 
consider and implement design changes necessary to integrate these 
systems into vehicles.
---------------------------------------------------------------------------

    \149\ https://dadss.org/news/updates/when-might-the-dadss-technology-be-in-u-s-cars-and-trucks.
---------------------------------------------------------------------------

b. Driver Monitoring of Inattention and Impairment Using Vehicle 
Equipment
    Another research initiative that NHTSA has conducted is a program 
with the University of Iowa National Advanced Driving Simulator called 
Driver Monitoring of Inattention and Impairment Using Vehicle Equipment 
(DrIIVE).\150\ The research program explored driver impairment through 
two separate tracks of research: (1) detection, and (2) mitigation. The 
main goal of the DrIIVE detection track was to develop and evaluate a 
system of vehicle-based algorithms to identify alcohol, drowsiness, and 
distraction impairment. Three impairment-detection algorithms, covering 
impairment from alcohol intoxication, drowsiness, and distraction, 
successfully detected matching impairment type (e.g., drowsiness 
algorithm identified drowsy drivers from a dataset of drowsy and non-
drowsy drivers) but had mixed results when applied to cross-impairment 
datasets (e.g., drowsiness algorithm identifying drowsiness from a 
dataset of drowsy and distracted drivers).
---------------------------------------------------------------------------

    \150\ Brown, T.L., & Schwarz, C.W., Jasper, J.G., Lee, J.D., 
Marshall, D., Ahmad, O. (in press) ``Driver Monitoring of 
Inattention and Impairment Using Vehicle Equipment (DrIIVE) Phase 
2.'' National Highway Traffic Safety Administration.
---------------------------------------------------------------------------

    The alcohol intoxication algorithm adapted well to the distracted 
and drowsy datasets, assuming that there was no alcohol intoxication 
present in those datasets (participants in the non-alcohol condition 
were neither dosed with alcohol, nor was BAC measured). The distraction 
algorithm also worked moderately well when applied to a cross-
impairment dataset, although it worked better with head pose 
incorporated as a driver-based sensor signal (e.g., head pose, body 
posture), as discussed further below.
    It is important to note that the DrIIVE projects have focused on 
vehicle-based sensor data; however, they have also incorporated driver-
based sensor signals. Additionally, the researchers investigated the 
benefits of taking individual differences between drivers into account 
in the training and operation of an algorithm. Driver-based sensors 
provided an added benefit to the performance and generalization of the 
distraction-detection algorithm, while individualizing the algorithms 
for individuals provided an added benefit to a drowsiness algorithm and 
an alcohol-intoxication algorithm. NHTSA recognizes that there are 
substantive challenges in individualizing algorithms across the entire 
driving population.
    Overall, the algorithms showed good success rates at correctly 
identifying driver impairment (and the correct source). However, the 
results of these studies also showed an interesting finding in which, 
in rare instances, drowsy drivers were categorized as alcohol impaired 
(despite not being dosed with alcohol). NHTSA has plans to initiate 
follow on research to refine the algorithm with the aim of determining 
if alcohol impairment detection can be achieved with a higher degree of 
accuracy. NHTSA recognizes the importance of accuracy of alcohol-
impaired driver detection so that non-impaired drivers are not 
inconvenienced.
    The DrIIVE mitigation research demonstrated the potential short-
term effectiveness of both haptic and auditory staged alerts (i.e., the 
ability to improve driving performance for a period of time after the 
drowsiness alert is provided). Results show that drowsy drivers who 
received mitigation alerts maintained better vehicle control and had 
fewer drowsy lane departures than drowsy drivers without this 
mitigation. Additionally, drowsy drivers with mitigation showed less 
variability in speed maintenance. Furthermore, the research suggested 
that staged alerts may be more effective than discrete alerts for very 
drowsy drivers. Finally, alert modality did not affect driving 
performance, nor did the alerts significantly lower self-reported 
drowsiness. NHTSA has ongoing warning mitigation research for 
intoxication.
c. NHTSA's November 12, 2020 Request for Information
    NHTSA also sought input from the public on impaired driving 
technologies through its November 12, 2020, NHTSA Request for 
Information (RFI).\151\ The notice requested information to inform 
NHTSA about the capabilities, limitations, and maturity of available 
technologies or those under advanced stages of development that target 
impaired driving. Specifically, it requested details about technologies 
that can detect degrees of driver impairment through a range of 
approaches including: (1) technologies that can monitor driver action, 
activity, behavior, or responses, such as vehicle movements during lane 
keeping, erratic control, or sudden maneuvers; (2) technologies that 
can directly monitor driver impairment (e.g., breath, touch-based 
detection through skin); (3) technologies that can monitor a driver's 
physical characteristics, such as eye tracking or other measures of 
impairment; and (4) technologies or sensors that aim to achieve direct 
measurement of a driver's physiological indicators that are already 
linked to forms of impaired driving (e.g., BAC level for alcohol-
impaired driving). NHTSA received 12 responses to the request for 
information. The following provides a high-level summary of those 
responses.
---------------------------------------------------------------------------

    \151\ 85 FR 71987, available at https://www.regulations.gov/docket/NHTSA-2020-0102.
---------------------------------------------------------------------------

    The Alliance for Automotive Innovation (Auto Innovators) noted that 
Driver State Monitoring and Driver Behavior Systems are promising 
technologies that, with continued development, have the potential to 
significantly reduce distracted and drowsy driving. The Auto Innovators 
also stated that they are ``. . . unaware of existing research 
demonstrating the robust effectiveness of these systems in detecting 
alcohol impairment. . . .'' The Auto Innovators further stated that 
``Driver State Monitoring/Driver Behavior Systems' ability to identify 
high-functioning individuals impaired by alcohol is unknown, but likely 
poor. Additional research is needed to understand the opportunities and 
limitations of these systems relative to individual alcohol impairment. 
Pre-operation systems, including DADSS, are not so limited because they 
are designed to quantify a driver's BAC.''
    Three automotive suppliers \152\ of camera-based DMSs and occupant 
monitoring systems responded to the November 12, 2020, Request for

[[Page 846]]

Information. Veoneer, a worldwide supplier of automotive technology, 
reported that it launched its first camera-based DMS to the market in 
2020. Its technology uses a true eye gaze system that determines the 
directional attributes of where the eyes are focused. Seeing Machines 
Limited, a DMS supplier, described their technology as providing 
evidence for the ability to reliably detect both drowsiness and visual 
distraction. Sony Depthsensing Solutions, an in-cabin occupant 
monitoring systems provider, described their ability to recognize 
driver features such as eye open/close and body position. The 
information they gain through sensors is used ``to extract higher level 
features such as drowsiness, microsleep, sleep, distraction (long and 
short) detection, emotion estimation or sudden sickness detection.'' 
Veoneer and Seeing Machines both noted that detecting driver alcohol 
impairment is more challenging and requires more technology development 
and research. Sony Depthsensing Solutions did not comment on the 
ability to detect other forms of impairment (e.g., alcohol). Eyegaze 
Inc., an eye tracking technology supplier, suggested their product, 
with additional work, could provide a solution to monitor driver 
attention when housed in an automobile.
---------------------------------------------------------------------------

    \152\ While not a passive device, a fourth supplier, Evanostics, 
provided information on a table-top oral fluid testing device that 
it suggests can test for alcohol and 10 classes of drugs in 15 
minutes. A second supplier, Impirica, provided information on a 
mobile (tablet and phone) based cognitive screening that is designed 
to evaluate real time driving impairment.
---------------------------------------------------------------------------

    Safety advocates generally provided support for vehicle safety 
technologies. The National Safety Council, a safety advocate group, 
stated their support for in-vehicle passive alcohol detection 
technology options and DMSs. The Advocates for Highway and Auto Safety, 
a roadway safety advocacy group, noted their support for vehicle safety 
technologies, including voicing support for crash avoidance 
technologies, expedited DADSS research and offender ignition 
interlocks, among other things. Mothers Against Drunk Driving (MADD) 
submitted two separate comment submissions to the docket, which 
included 241 examples of technology related to detection of alcohol in 
blood or breath, other indicators of alcohol intoxication, drug 
impairment, drowsiness, and driver distraction/inattention. Finally, a 
submission by the American National Standards Institute, Inc, provided 
research references on eye tracking as an indicator of impairment.
d. Technology Scans
    In addition to the aforementioned RFI, NHTSA contracted with two 
different groups to independently review the state of publicly 
available information related to impairment detection. The first is an 
update to the ``Review of Technology to Prevent Alcohol- and Drug-
Impaired Crashes (TOPIC)'' report.\153\ This report updates the 2007 
evaluation of vehicular technology alternatives to detect driver BAC 
and alcohol-impaired driving. It includes additional findings related 
to the detection of impaired driving due to drugs other than alcohol, 
drowsiness, and distraction. This report reviews relevant literature 
and technologies and incorporates input from stakeholders and the 
public (i.e., information received from the RFI). The report finds that 
tissue spectroscopy technologies are more accurate in estimating BAC 
than other technologies available at this time. Although driver 
attention monitoring technologies are presently able to detect drowsy 
driving and distracted driving, none specifically able to detect 
alcohol- or drug-impaired driving were found to be commercially 
available.
---------------------------------------------------------------------------

    \153\ Pollard, J.K., Nadler, E.D., & Melnik, G.A. (In Press). 
Review of Technology to Prevent Alcohol- and Drug-Impaired Crashes 
(TOPIC): Update. National Highway Traffic Safety Administration.
---------------------------------------------------------------------------

    The second technology scan is ``Assessment of Driver Monitoring 
Systems for Alcohol Impairment Detection and Level 2 Automation.'' The 
report presents a review of DMS for alcohol impairment detection. A 
total of 331 systems were reviewed, more than 280 of which met 
inclusion criteria and are included in the report. The study found that 
few technologies are commercially available for alcohol impairment 
detection; some were not designed for in-vehicle use, and others were 
identified based on patent applications rather than evidence of 
functional systems. The review focused on features that were explicitly 
mentioned or indicated on the manufacturers' websites, patents, device 
manuals, publications, or reports. The review, which was completed in 
October 2022, noted that camera-based DMS have been in vehicles since 
2018 for monitoring driver inattention to the forward roadway for SAE 
Level 2 driving automation systems,\154\ as well as other vehicle-based 
sensors such as lane position monitoring and steering wheel torque 
monitoring to measure driver engagement and performance.
---------------------------------------------------------------------------

    \154\ SAE International, Standard J3016, ``Taxonomy and 
Definitions for Terms Related to On-Road Motor Vehicle Automated 
Driving Systems,'' April 2021.
---------------------------------------------------------------------------

    The DMS were reviewed with a focus on the applicability of each 
system to driver alcohol impairment detection. The systems were 
classified as physiology-based, tissue spectroscopy-based, camera-
based, vehicle kinematics-based, hybrid (i.e., two or more of the 
classification types), and patent-stage systems. A key focus was to 
review systems that are being developed with the potential to detect 
alcohol-based driving impairment, as well as systems that can precisely 
estimate BAC.
    Of the systems reviewed, no commercially available product was 
found to estimate the amount of alcohol or identify alcohol-based 
impairment in the driver during the driving task. Behavioral indicators 
investigated included eye glances, facial features, posture, and 
vehicle kinematic metrics. However, systems with these capabilities are 
currently at various stages of the research and development process.
    Based on industry stakeholder interviews and expert review of 
technology documentation, the researchers found that approaches that 
are furthest along in the development process are those which measure 
the presence and amount of alcohol in a person's body using BrAC and 
tissue spectroscopy. Camera-based and most physiology-based DMS are 
still in stages of preliminary research and design for alcohol-based 
impairment detection in passenger vehicles. The efficacy of vehicle 
kinematic measures in identifying alcohol-based impairment is currently 
unknown. Finally, hybrid systems are promising in being able to discern 
between driver states due to the number of different measures used in 
making state determinations.
e. NHTSA's Driver Monitoring Research Plans
    In addition to state-of-the-art assessments on DMSs, NHTSA has 
conducted research on driver state monitoring used in conjunction with 
SAE Level 2 driving automation.\155\ While using Level 2 driving 
automation, drivers are expected to both monitor the environment and 
supervise vehicle automation which is simultaneously providing lateral 
and longitudinal support to the driver. Some systems do not require the 
driver to have their hands on the wheel, while others include advanced 
features like automated lane changes and point-to-point navigation. The 
research included a literature review, stakeholder interviews, and 
system assessments. Many, but not all, Level 2 driving automation 
systems monitor visual and physical driver indicators, using camera-
based sensing systems. Useful

[[Page 847]]

measures of general driver visual attention include measures of eye/
pupil movement (e.g., fixation duration), measures of glance location 
(e.g., eyes on/off road), and measures of glance spread and range 
(e.g., scan path).
---------------------------------------------------------------------------

    \155\ Prendez, D.M., Brown, J.L., Venkatraman, V., Textor, C., 
Parong, J., & Robinson, E. (in press). Assessment of Driver 
Monitoring Systems for Alcohol Impairment Detection and Level 2 
Automation. National Highway Traffic Safety Administration.
---------------------------------------------------------------------------

    While NHTSA's research on DMS for Level 2 driving automation 
systems has implications for DMS applied to detection of alcohol 
impairment with regard to technological feasibility, there are 
important differences between these two applications. The safety 
issues, indicators and measures of driver risk, consumer acceptance, 
and potential interventions may be different for Level 2 driving 
automation than they are for alcohol impairment. For example, drivers 
who are impaired by alcohol may appear to be visually attentive as 
measured by eye gaze toward the forward roadway, so alternative 
measures will be important to achieve reliable detection of impairment. 
Additionally, while alerts may prompt inattentive drivers to return 
their attention to the road, alerts alone cannot remedy driver 
impairment from alcohol. Additionally, the use of Level 1 and higher 
driving automation itself may pose challenges for the detection of 
alcohol impairment. This is because some of the driving performance 
measures that may be indicative of alcohol impairment (e.g., 
instability of lane position and speed) cannot be used when the vehicle 
itself is controlling that portion of the dynamic driving task. NHTSA 
is currently conducting research examining distraction that does not 
specifically focus on drunk driving or metrics but might be helpful to 
consider if the agency pursues an approach that requires camera-based 
driver monitoring to detect drunk driving.
2. Passive Detection Methods and Available Technologies
    The ``advanced drunk and impaired driving prevention technology'' 
under BIL prescribes three methods of passive detection--(1) passively 
monitor the performance of a driver of a motor vehicle to accurately 
identify whether that driver may be impaired; (2) passively and 
accurately detect whether the blood alcohol concentration of a driver 
of a motor vehicle is equal to or greater than the blood alcohol 
concentration described in section 163(a) of title 23, United States 
Code; \156\ or (3) a combination of the first and second options.
---------------------------------------------------------------------------

    \156\ 23 U.S.C. 163(a) states ``The Secretary shall make a 
grant, in accordance with this section, to any State that has 
enacted and is enforcing a law that provides that any person with a 
blood alcohol concentration of 0.08 percent or greater . . .''.
---------------------------------------------------------------------------

    NHTSA interprets the first option as passively monitoring the 
driver's performance (e.g., eyes on the forward roadway; taking 
appropriate steering, braking, or accelerating action) to gain an 
accurate determination of whether the driver may be impaired. Since 
``driver impairment'' could include more than just alcohol-impairment, 
the collective states of driver impairment would constitute the largest 
real-world safety problem. NHTSA interprets the second option to 
require passive and accurate detection of BAC over a prescribed limit 
(which is currently .08 g/dL). This would exclusively target a subset 
of driver impairment conditions (i.e., alcohol-impaired drivers) 
focused on BAC detection. Alcohol-impaired drivers constitute the 
largest fatal driver impairment type. The third option is a combination 
of both the first and second. The following subsections discuss each of 
these options.
a. Passively Monitor the Performance of a Driver To Accurately Identify 
Whether That Driver May Be Impaired
    For the purposes of this section, the following driver impairments 
were considered: drowsiness, distraction, and drunk, in the order of 
increasing fatality counts in the United States. While drugged driving 
is another known driver impairment, the ability to explicitly detect 
drug-impaired drivers is currently limited. Some of the effects of 
drugged driving, however, may be similar to the effects of alcohol-
impaired or distracted driving, and therefore it is possible that 
vehicle technologies designed to detect other forms of impairment may 
also have the ability to detect some drug-induced impairments as well. 
As stated in the introduction, NHTSA is considering prioritizing 
alcohol impairment due to the significant safety problem caused by 
drivers intoxicated by alcohol and requests comment on whether that 
scope is most appropriate and whether its focus should be expanded to 
other types of impairment, including those discussed in this section.
    Driver performance generally consists of being attentive to the 
driving task, and taking appropriate vehicle control actions (i.e., 
steering, accelerating, and braking). Modern vehicles are equipped with 
many crash avoidance and driver assistance sensors that may provide 
opportunity to contribute to the detection of driver impairment. The 
following provides examples of those sensing technologies.
    Camera-Based Driver Monitoring Sensors: Camera-based DMSs are 
becoming more prevalent in vehicles with Level 2 driving automation 
features (i.e., adaptive cruise control and lane centering).\157\ NHTSA 
reviewed several available and prototype camera-based driving 
monitoring systems that publicly state the ability to monitor aspects 
of driver state, including driver's eye gaze, eyelid/eye closure, pupil 
size, head/neck position, posture, hand/foot position, and facial 
emotion during the driving task.\158\ The review found that most 
systems are currently available and intended for use in detecting 
driver drowsiness, inattention, and sudden sickness/non-responsive 
drivers and few are for specifically detecting alcohol-impairment. 
Although measures such as eye closure over time, pupil diameter, 
saccades (an eye movement between fixations), and fixations are 
parameters under study for detecting alcohol impairment, the review 
found that there was a lack of clinical and psychophysiological 
research to aid in specifically detecting driver alcohol impairment. 
The review found only three systems that claimed alcohol-based 
impairment detection as the objective, but the systems with these 
capabilities are not available on the market.
---------------------------------------------------------------------------

    \157\ The Path to Safe Hands-Free Driving [bond] GM Stories; 
Ford BlueCruise [bond] Consumer Reports Top-Rated Active Driving 
Assistance System [bond] Ford.com; Nissan ProPILOT Assist Technology 
[bond] Nissan USA; Teammate Advanced Drive Backgrounder--Lexus USA 
Newsroom.
    \158\ Prendez, D.M., Brown, J.L., Venkatraman, V., Textor, C., 
Parong, J., & Robinson, E. (in press). Assessment of Driver 
Monitoring Systems for Alcohol Impairment Detection and Level 2 
Automation. National Highway Traffic Safety Administration.
---------------------------------------------------------------------------

    It is notable, however, that other past NHTSA research suggested 
that the driver states of drowsiness and alcohol-impairment can present 
similarly to a driver monitoring system.\159\ So there may be an 
opportunity ``to detect'' some alcohol-impaired drivers that present as 
drowsy. However, as discussed further below, the countermeasure for 
``prevention'' applied to a sober drowsy driver, as opposed to an 
alcohol-impaired driver, may not be the same. For example, NHTSA 
contemplates and seeks comment on whether a sober drowsy driver may 
respond favorably to a warning and may even take a break from driving 
to recover, whereas an alcohol-impaired driver may not respond to a 
warning at all, or worse,

[[Page 848]]

respond in a negative way (e.g., becoming a more risky driver).
---------------------------------------------------------------------------

    \159\ Brown, T.L., & Schwarz, C.W, Jasper, J.G., Lee, J.D., 
Marshall, D., Ahmad, O. (in press) ``Driver Monitoring of 
Inattention and Impairment Using Vehicle Equipment (DrIIVE) Phase 
2.'' National Highway Traffic Safety Administration.
---------------------------------------------------------------------------

    Hands-On-Wheel Sensors: Drivers with their hands off the steering 
wheel for an extended period of time can be an indicator of driver 
inattention. Vehicles equipped with Level 2 features often have 
capacitive or steering torque sensors to confirm that the driver has at 
least one hand on the steering wheel. Capacitive sensing detects the 
change in capacitance of the steering wheel that results from the 
driver's hands being removed from the wheel. Steering wheel torque 
sensing detects small steering inputs made by the driver. These sensors 
are commonly used in algorithms to encourage drivers to remain 
attentive during driving.\160\ It should be noted, however, that some 
Level 2 feature designs permit hands-off-wheel while supervising the 
vehicle automation. Current production vehicles with Level 2 features 
that permit drivers to remove their hands from the wheel have camera-
based DMS that alert drivers if they look away from the forward roadway 
for more than a few seconds.
---------------------------------------------------------------------------

    \160\ Driver Monitoring [bond] Alliance For Automotive 
Innovation (autosinnovate.org).
---------------------------------------------------------------------------

    Lane Departure and Steering Sensors: Poor precision as indicated by 
unintended lane excursions may indicate unsuitable driver states, 
including alcohol-based impairment.\161\ Alcohol reduces driving 
precision, and lane positioning is a key skill that is affected, even 
at low doses. Deviation of lane position from the lane center increases 
with increasing doses of alcohol.\162\ The Standard Deviation of Lane 
Position (SDLP) is considered a sensitive (but not specific) measure of 
alcohol impairment.\163\ Relatedly, measures of steering inputs can be 
used to detect alcohol impairment.\164\ Specifically, drivers who are 
impaired due to alcohol may exhibit more erratic driving patterns with 
tendencies to deviate from their lane position.\165\
---------------------------------------------------------------------------

    \161\ https://www.nhtsa.gov/sites/nhtsa.gov/files/808677.pdf.
    \162\ Harrison, E.L., & Fillmore, M.T. (2005). Are bad drivers 
more impaired by alcohol? Sober driving precision predicts 
impairment from alcohol in a simulated driving task. Accident 
Analysis & Prevention, 37(5):882-9. doi: 10.1016/j.aap.2005.04.005; 
Lee JD, Fiorentino D, Reyes ML, Brown TL, Ahmad O, Fell J, Ward N, 
Dufour R. (2010). Assessing the Feasibility of Vehicle-Based Sensors 
to Detect Alcohol Impairment. National Highway Traffic Safety 
Administration. Report No. DOT HS 811-358; Calhoun, V.D. & Pearlson, 
G.D. (2012). A selective review of simulated driving studies: 
Combining naturalistic and hybrid paradigms, analysis approaches, 
and future directions. NeuroImage, 59(1), 22-35; Irwin C, Iudakhina 
E, Desbrow B, McCartney D. (2017). Effects of acute alcohol 
consumption on measures of simulated driving: A systematic review 
and meta-analysis. Accident Analysis & Prevention, (102),248-266. 
doi: 10.1016/j.aap.2017.03.001. Epub 2017 Mar 24. PMID: 28343124.
    \163\ Irwin C, Iudakhina E, Desbrow B, McCartney D. (2017). 
Effects of acute alcohol consumption on measures of simulated 
driving: A systematic review and meta-analysis. Accident Analysis & 
Prevention, (102)248-266. doi: 10.1016/j.aap.2017.03.001. Epub 2017 
Mar 24. PMID: 28343124.
    \164\ Das D., Zhou S., Lee J. D. (2012). Differentiating 
alcohol-induced driving behavior using steering wheel signals. IEEE 
Trans. Intel. Transp. Syst. 13 1355-1368. 10.1109/TITS.2012.2188891.
    \165\ Kersloot, Tanita & Flint, Andrew & Parkes, Andrew. (2003). 
Steering Entropy as a Measure of Impairment.
---------------------------------------------------------------------------

    The following crash avoidance sensor technologies equipped on 
modern vehicles could aid in detecting lane departure: forward-looking 
external cameras; steering wheel torque sensors; and blind spot 
detection sensors.
    When driven manually, forward-looking external cameras commonly 
used in lane departure warning systems have the potential to identify a 
vehicle drifting out of its travel lane, typically when lane markings 
are present and observable (i.e., not snow-covered or worn). This could 
include drifting off the roadway or drifting into oncoming traffic. 
Tracking a vehicle's lane departure warning activations over time could 
present as an indicator of a driver directing the vehicle to weave in 
and out of its travel lane (weaving and weaving across lanes are cues 
used by officers in detection of impaired driving).\166\ NHTSA's 
research suggests that many vehicle manufacturers use lane position 
monitoring for detecting unintentional lane drift from several driver 
impairments--drowsiness and inattention.\167\ Some vehicle 
manufacturers were found to use lane position monitoring in available 
features, such as oncoming lane mitigation and run-off road 
mitigation.\168\
---------------------------------------------------------------------------

    \166\ https://www.nhtsa.gov/sites/nhtsa.gov/files/808677.pdf
    \167\ Prendez, D.M., Brown, J.L., Venkatraman, V., Textor, C., 
Parong, J., & Robinson, E. (in press). Assessment of Driver 
Monitoring Systems for Alcohol Impairment Detection and Level 2 
Automation. National Highway Traffic Safety Administration.
    \168\ Prendez, D.M., Brown, J.L., Venkatraman, V., Textor, C., 
Parong, J., & Robinson, E. (in press). Assessment of Driver 
Monitoring Systems for Alcohol Impairment Detection and Level 2 
Automation. National Highway Traffic Safety Administration.
---------------------------------------------------------------------------

    Some vehicles are equipped with steering wheel torque sensors that 
monitor a driver's steering inputs. Such sensors could detect and 
monitor erratic steering corrections over time during the course of a 
trip. NHTSA's research suggests that some vehicle manufacturers use 
steering input monitoring for detecting inattention, drowsiness, or 
sudden sickness/non-responsive driver for vehicles equipped with Level 
2 systems (used in an active emergency stop assist application).\169\
---------------------------------------------------------------------------

    \169\ Prendez, D.M., Brown, J.L., Venkatraman, V., Textor, C., 
Parong, J., & Robinson, E. (in press). Assessment of Driver 
Monitoring Systems for Alcohol Impairment Detection and Level 2 
Automation. National Highway Traffic Safety Administration.
---------------------------------------------------------------------------

    Many modern vehicles also come with blind spot warning sensors on 
the sides of the vehicle that can identify a vehicle in an adjacent 
lane.\170\ If an impaired driver attempts to steer into an adjacent 
lane of travel when another vehicle is in its blind spot, a vehicle 
equipped with this technology can warn the driver, or in some vehicles, 
even intervene via active blind spot intervention technology.
---------------------------------------------------------------------------

    \170\ https://www.nhtsa.gov/equipment/driver-assistance-technologies.
---------------------------------------------------------------------------

    Speed/Braking Sensors: Speed maintenance is generally affected by 
high BAC levels. NHTSA's research has found that driver alcohol doses 
greater than BAC .05 g/dL can significantly impair an individual's 
ability to maintain appropriate speed, particularly in complex 
environments.\171\ While some studies report increased speeds by 
alcohol-impaired drivers, others report speed decreases.\172\ The 
reduced ability to maintain consistent speed is referred to as the 
Standard Deviation of Speed Deviation (SDPD), which is commonly used to 
measure relative performance of impaired drivers compared to control 
groups. While findings concerning speed directionality (i.e., increase 
or decrease) are mixed, studies have consistently shown that speed 
deviation from posted speed limits tends to increase in alcohol-
impaired driver groups.\173\
---------------------------------------------------------------------------

    \171\ Veldstra et al., 2012; Mets et al., 2011.
    \172\ Rezaee-Zavareh et al., 2017; Lee et al., 2010; West et 
al., 1993; Irwin et al., 2017; Lenne et al., 2010.
    \173\ Arnedt et al., 2001; Yadav & Velaga, 2020; Irwin et al., 
2017.
---------------------------------------------------------------------------

    That said, some forward-looking external cameras can detect and 
interpret posted speed limit signs, which could provide an indicator of 
speeding when compared to the actual speed the vehicle is traveling. 
Some vehicles have telematics and maps that provide posted speed limit 
information. Vehicles also have brake sensors that could be monitored 
over time to sense repeated incidences of hard braking during a trip.
    Time-Based Sensors: Two other vehicle sensors that could be used in 
an overall driver impairment algorithm include duration of trip, and 
time of day. Monitoring the trip duration is used in some vehicle 
algorithms to warn about drowsy driving.\174\ After a certain

[[Page 849]]

length of time, a vehicle may provide an icon (e.g., a coffee cup-like 
symbol) on the instrument panel to suggest a driver take a break from 
the driving task. Monitoring the trip duration may also help in 
identifying repeated lane departures over time. Monitoring the time of 
day could be added to other detection methods to help confirm detection 
of drowsiness or alcohol-impairment states at late night times. Most 
alcohol-impaired driving fatalities in the United States occur between 
6 p.m. and 3 a.m.\175\
---------------------------------------------------------------------------

    \174\ Driver Attention Warning [bond] Hyundai.
    \175\ Traffic Safety Facts 2020: A Compilation of Motor Vehicle 
Crash Data (dot.gov) Table 31.
---------------------------------------------------------------------------

    Physiological Sensors: There are also a variety of physiological-
based systems under research that use biometric measures from the 
driver to infer driver state. These could include heart rate, sweat, 
and blood pressure, among others. NHTSA's research found that many were 
in the research and development stage, including those for breath 
alcohol detection (which will be discussed in the next section).\176\ A 
practical limitation of their use may be the fact that detecting driver 
impairment may be reliant upon background knowledge of a specific 
driver's baseline physiological characteristics (to sense elevated 
levels) and can be attributable to multiple physiological states (e.g., 
stress).
---------------------------------------------------------------------------

    \176\ Prendez, D.M., Brown, J.L., Venkatraman, V., Textor, C., 
Parong, J., & Robinson, E. (in press). Assessment of Driver 
Monitoring Systems for Alcohol Impairment Detection and Level 2 
Automation. National Highway Traffic Safety Administration.
---------------------------------------------------------------------------

    In summary, NHTSA's research suggests that many driver impairment 
detection strategies use different combinations of measures, but the 
available documentation of multi-detection approaches is rare, and when 
present, details of the underlying algorithms are sparse.\177\ It is 
reasonable to assume that the combination of more sensors and driver 
metrics will improve the confidence in driver state inference. Little 
data is available, however, to inform NHTSA on which combination of 
sensors and indicators of driver state, if any, would achieve greater 
accuracy and reliability of impairment detection.
---------------------------------------------------------------------------

    \177\ Prendez, D.M., Brown, J.L., Venkatraman, V., Textor, C., 
Parong, J., & Robinson, E. (in press). Assessment of Driver 
Monitoring Systems for Alcohol Impairment Detection and Level 2 
Automation. National Highway Traffic Safety Administration.
---------------------------------------------------------------------------

    Vehicle manufacturers have announced concept vehicles or production 
plans for active/passive technologies to mitigate alcohol-impaired 
driving for many years. For example, a media article \178\ cited 
alcohol-impaired driver research by General Motors dating back to the 
1970s on a critical tracking test (CTT) ``experimental deterrent'' that 
used the result from a 10-second test the driver took each time he or 
she got behind the wheel to determine whether the car would start. 
Tests were reported to use driver steering wheel movement and a gauge 
on the instrument panel where the driver would have to keep the needle 
on the gauge in the acceptable range through a series of progressive 
needle movements. Another concept involved cognitive tests where a 
series of five numbers appeared above five numbered white buttons on 
the instrument panel (or on a keypad). To pass the test, the driver 
must replicate the number sequence by using buttons and complete it in 
a designated timeframe.
---------------------------------------------------------------------------

    \178\ A GM onboard experimental alcohol and drug impairment 
detection device of the 1970s [bond] Hemmings
---------------------------------------------------------------------------

    More recently, a 2016 patent held by General Motors, ``Method and 
System for Mitigating the Effects of an Impaired Driver,'' aims to 
detect inattention and alcohol-based impairment through use of camera-
based detection measures (i.e., eye gaze, eyelid/eye closure, and 
facial/emotional measures), as well as lane monitoring and steering 
input.\179\
---------------------------------------------------------------------------

    \179\ Prendez, D.M., Brown, J.L., Venkatraman, V., Textor, C., 
Parong, J., & Robinson, E. (in press). Assessment of Driver 
Monitoring Systems for Alcohol Impairment Detection and Level 2 
Automation. National Highway Traffic Safety Administration.
---------------------------------------------------------------------------

    Similarly, in 2007, Toyota announced its intent to create a fail-
safe system for cars that detects drunk drivers and automatically shuts 
the vehicle down if sensors pick up signs of excessive alcohol 
consumption. According to a media report,\180\ cars fitted with the 
detection system will not start if sweat sensors in the driving wheel 
detect high levels of alcohol. The system could also detect abnormal 
steering, or if a special camera shows that the driver's pupils are not 
in focus, the car would be slowed to a halt. Toyota had reportedly 
hoped to fit cars with the system by the end of 2009. NHTSA does not 
know the current status of this Toyota technology and seeks comment on 
its effectiveness and availability.
---------------------------------------------------------------------------

    \180\ Toyota creating alcohol detection system (nbcnews.com).
---------------------------------------------------------------------------

    During the same timeframe, Nissan also reportedly developed a 
concept car with technology to detect alcohol in the breath and sweat 
of the driver.\181\ Nissan's concept car had an alcohol sensor in the 
transmission shift knob, and in the driver's and passenger's seats. 
Both reportedly worked together to detect traces of alcohol in the 
cabin past a certain threshold. If the driver's seat or shift knob had 
detected any alcohol while still parked, the transmission locked and 
made the car immobile. A second feature was a facial monitoring system 
built to monitor signs of drowsiness or distraction by monitoring the 
driver blinking rate. Once detected, a voice message alert was issued, 
and the seat belt was tightened to gain the attention of the driver. A 
third concept that was further developed after the 2007 timeframe was a 
road monitoring system. Nissan put technology in vehicles that 
monitored lanes and alerted drivers when the vehicle drifted out of the 
current lane, which Nissan reportedly believed mitigated safety risks 
associated with distracted driving.
---------------------------------------------------------------------------

    \181\ Nissan Is Ahead of Its Time in Developing Anti-Drunk 
Driving Technology Over a Decade Before Potential Federal Mandate 
[bond] GetJerry.com.
---------------------------------------------------------------------------

    Hyundai Mobis, a global Tier 1 \182\ supplier, has been researching 
a technology called DDREM--Departed Driver Rescue and Exit Maneuver. 
Initially announced at the Consumer Electronics Show in 2018,\183\ 
DDREM uses an infrared camera to capture driver facial and eye 
movements to determine if the driver keeps eyes forward, changes 
blinking patterns, or exhibits other signs of drowsiness. The 
technology also looks for key identifiers used in advanced driver 
assistance systems (e.g., if the driver is moving in and out of a lane, 
crossing lanes, zig zagging, or making erratic movements).
---------------------------------------------------------------------------

    \182\ Tier 1 suppliers are companies that are direct suppliers 
to Original Equipment Manufacturers (OEM).
    \183\ https://www.businesswire.com/news/home/20180103005023/en/2018-CES-Hyundai-Mobis-Announces-Lifesaving-Autonomous-Vehicle-Technology-to-Potentially-Eliminate-Drowsy-Driving-Fatalities, last 
accessed July 7, 2023.
---------------------------------------------------------------------------

    On March 20, 2019, Volvo Cars announced plans to deploy in-car 
cameras and intervention against intoxication and distraction.\184\ Its 
press release stated, ``Volvo Cars believes intoxication and 
distraction should be addressed by installing in-car cameras and other 
sensors that monitor the driver and allow the car to intervene if a 
clearly intoxicated or distracted driver does not respond to warning 
signals and is risking an accident involving serious injury or death.'' 
The press release provided examples of behaviors to be detected: a 
complete lack of steering input for extended periods of time, drivers 
who are detected to have their eyes closed or off the road for extended

[[Page 850]]

periods of time, as well as extreme weaving across lanes or excessively 
slow reaction times. It further stated introduction of the cameras on 
all Volvo models will start on the next generation of Volvo's scalable 
SPA2 vehicle platform in the early 2020s.
---------------------------------------------------------------------------

    \184\ https://www.media.volvocars.com/global/en-gb/media/pressreleases/250015/volvo-cars-to-deploy-in-car-cameras-and-intervention-against-intoxic.
---------------------------------------------------------------------------

    Most recently, Volvo introduced the model year 2024 Volvo EX 90 
that has a ``Driver Understanding System,'' which uses two interior 
sensors and a capacitive steering wheel along with the vehicle's 
exterior sensors to understand if a driver is distracted or drowsy and 
when the vehicle may need to step in and support.\185\
---------------------------------------------------------------------------

    \185\ 2024 Volvo EX90 Full Electric 7 Seater SUV [bond] Volvo 
Car USA (volvocars.com) According to its website, the vehicle's 
``Pilot Assistance'' feature ``can help keep an eye on the traffic 
and lane markings and support you by adapting your speed and 
distances given the current driving conditions. It can provide speed 
control in steep curves and steering support while changing lanes. 
If the car detects any sign of the driver being unresponsive, it can 
brake the vehicle to a standstill within the lane.''
---------------------------------------------------------------------------

    Given the advancements in driver impairment detection (i.e., due to 
use in combination with SAE Level 2 driving automation technology), it 
is expected that other approaches will improve over time as strategies 
for mitigating inattention, incapacitation, drowsiness, and alcohol-
impairment detection evolve--both from a technology perspective and a 
consumer acceptance stance. For example, Consumer Reports published an 
article suggesting that early versions of these driver impairment 
technologies are already appearing on cars in other countries.\186\ 
NHTSA seeks comment on the current state of technology and its 
effectiveness in passively detecting driver impairment.
---------------------------------------------------------------------------

    \186\ https://www.consumerreports.org/car-safety/driver-monitoring-can-pull-car-over-if-driver-incapacitated-a1204997865/ 
``Some Volkswagen Arteon sedans sold in Europe and equipped with the 
Emergency Assist 2.0 feature will turn on their flashers and pull 
over to the side of the road if a driver becomes unresponsive. 
According to the automaker, if the car senses that a driver is not 
using the accelerator, brake, or steering wheel, it will first try 
to awaken a driver by sounding alarms and tapping the brakes to 
``jolt'' the driver into awareness. If the driver still doesn't 
respond, it will automatically steer itself to the lane furthest 
from traffic on a multilane road and bring the vehicle to a stop. In 
Japan, Mazda has said it will debut its Co-Pilot system on new 
vehicles this year. Tamara Mlynarczyk, a Mazda spokesperson, tells 
CR that the system is ``continuously monitoring'' the driver's 
performance. ``In a potential emergency situation where the driver 
loses consciousness, the system is prepared to intervene and assist 
the driver or pull the car over to a safer location,'' she says. On 
a multilane road, it may be able to pull the vehicle to the road's 
shoulder.''
---------------------------------------------------------------------------

Questions on Technologies That Passively Monitor the Performance of a 
Driver To Accurately Detect Whether That Driver May Be Impaired
    1.1. NHTSA requests feedback on the two technology scan findings. 
Are there technologies, or technology capabilities or limitations not 
captured in these reports? If so, what are they?
    1.2. NHTSA is concerned that behaviors consistent with drunk 
driving, like repeated potential lane departure and erratic speeding/
braking, would be masked by an engaged SAE Level 2 driving automation 
systems. Would there be enough information from other sensors (e.g., 
camera-based DMS, hands-on-wheel detection) to detect driver impairment 
and driver impairment type when SAE Level 1 or 2 driving automation 
systems are active? \187\
---------------------------------------------------------------------------

    \187\ 2020 Data: Alcohol-Impaired Driving (dot.gov).
---------------------------------------------------------------------------

    1.3. NHTSA is concerned about the limitations of vehicle sensor-
based impairment detection systems to operate fully when certain 
sensors are impeded. External circumstances may include common roadway 
conditions such as darkness, heavy weather, roads with poor markings, 
or unpaved roads. Circumstances within the vehicle may include driver 
accessories, such as infrared light-blocking sunglasses, masks, or hats 
that may obscure the view of the driver to a DMS camera. If one or more 
sensors are impeded by such conditions, is there enough information 
from other sensors to detect driver impairment? Does this vary by 
impairment type? What are the operational limitations of such systems?
    1.4. NHTSA is seeking input on how a test procedure for driver 
impairment detection systems could be developed and executed in a 
FMVSS. For example, does the test need to be conducted in a moving 
vehicle to capture lane drift or weaving? If so, what are potential 
testing approaches or procedures? Are humans required for camera-based 
DMS assessment? Are there particular accessories (e.g., sunglass types, 
facial coverings) that would be required for testing? Is it feasible to 
conduct testing in darkness? What type of accuracy could be attained? 
How might this vary based on intended impairment type detection?
    1.5. What kind of performance requirement should NHTSA consider to 
mitigate defeat strategies (e.g., taping over the camera-based DMS or 
removing/replacing rear-view mirrors that contain driver monitoring 
equipment)?
    1.6. What metrics and thresholds (e.g., eye gaze, lane departure 
violations, speed, blind spot warning triggers, lane position 
variability, speed variability), or combination thereof, are most 
effective at measuring driver impairment? These would include time-
based parameters from the start of the ignition cycle and those used 
for continuous monitoring. How feasible is it to implement these 
metrics in passenger vehicles? Should these vary by impairment type? 
Might these measures conflict across impairment types? Should NHTSA 
require impairment detection systems be able to collect specific 
metrics? Why or why not?
    1.7. NHTSA seeks comment on whether it should be necessary for an 
impairment detection system to determine what kind of impairment a 
driver has (e.g., drowsy, distracted, drunk) if the driver triggers 
certain metrics that indicate the driver is impaired by at least one of 
those impairments? For example, incapacitation, drowsiness, and 
distraction could be captured by camera-based monitoring systems, but 
they may also detect some alcohol-impaired drivers.
    1.8. Are there characteristics that would separate sober 
impairments from alcohol-induced impairments (e.g., horizontal gaze 
nystagmus or myokymia)? If so, what are they? Are there other non-
alcohol induced conditions in which some of these characteristics might 
appear? If so, please provide examples.
    1.9. NHTSA seeks comment about whether certain conditions listed in 
the previous question (e.g., myokymia) might result in false positives 
\188\ in certain situations (e.g., stress) or with certain populations 
(e.g., older drivers).
---------------------------------------------------------------------------

    \188\ A false positive could occur when the system indicates a 
person is at the detection level for impairment, when they are not 
impaired.
---------------------------------------------------------------------------

    1.10. What precision and accuracy should driver monitoring 
technology be required to meet for the purposes of detecting alcohol 
impairment? Under what conditions should these technologies be 
demonstrated to work? Are there driver characteristics, environmental 
conditions, or other factors that might limit the usefulness or 
applicability of certain technologies under certain conditions? Should 
there be a maximum time allowed for a system to develop a determination 
of impairment, after the indicators of impairment are detected?
    1.11. Under what conditions should a vehicle allow a driver to turn 
off driver impairment monitoring, if at all? If

[[Page 851]]

allowed, should a system be reset to ``on'' upon the next ignition 
cycle?
    1.12. NHTSA is interested in data, studies, or information 
pertaining to the effectiveness of various sensors or algorithms in 
correctly detecting driver impairment (collectively, and individual 
impairments). NHTSA is seeking comment on which metrics, thresholds, 
sensors, and algorithms employed by existing DMS technology that could 
be used in an alcohol impairment detection system could be sufficiently 
robust to meet the requirement that an FMVSS be objective.
    1.13. Are there other innovative technologies, such as impaired-
voice recognition,\189\ that could be used to detect driver impairment 
at start-up? If so, how might these function passively without 
inconveniencing unimpaired drivers? How mature and accurate are these 
technologies?
---------------------------------------------------------------------------

    \189\ https://neurosciencenews.com/ai-alcohol-voice-22191/.
---------------------------------------------------------------------------

    1.14. What level of sensitivity and specificity is necessary to 
ensure the DMS technology does not unduly burden unimpaired drivers or 
prevent unimpaired drivers from driving? Are there any DMS available on 
the market capable of detecting alcohol impairment with the level of 
sensitivity and specificity necessary to ensure this?
    1.15. How can developers of DMS technology ensure that people with 
disabilities are not disproportionately impacted? Specifically, how can 
the technology accurately account for facial/body differences, chronic 
health conditions, and adaptive driving technologies?
    1.16. How repeatable and reliable must these systems be? Is there 
societal acceptance of some potential false positives that could 
inconvenience sober drivers knowing that it would capture drunk 
drivers? If so, what countermeasure might best facilitate this? In 
considering a possible performance standard, what false positive rate 
would place too great a burden on unimpaired drivers?
    1.17. What can be done to mitigate physical destruction or misuse 
concerns? If mitigations exist, how might these mitigations impact the 
effectiveness of DMS monitoring driver impairment?
    1.18. NHTSA seeks to ensure fairness and equity in its programs and 
regulations. As NHTSA considers technologies that can passively detect 
impairment, some of which monitor facial features through camera-based 
systems or voice recognition, how can NHTSA, in the context of an 
FMVSS, best ensure these systems meet the needs of vehicle users of all 
genders, races and ethnicities, and those with disabilities?
b. Passively and Accurately Detect Whether the Blood Alcohol 
Concentration of a Driver of a Motor Vehicle Is Equal to or Greater 
Than the Blood Alcohol Concentration Described in Section 163(a) of 
Title 23, United States Code
    The second option presented in BIL is one that requires the passive 
and accurate detection of a driver of a motor vehicle whose BAC is 
equal to or greater than the BAC described in Section 163 (a) of title 
23, United States Code.
    Section 163(a) of title 23 of the United States Code currently 
reads as follows:
    (a) General Authority.--
    The Secretary shall make a grant, in accordance with this section, 
to any State that has enacted and is enforcing a law that provides that 
any person with a blood alcohol concentration of 0.08 percent or 
greater while operating a motor vehicle in the State shall be deemed to 
have committed a per se offense of driving while intoxicated (or an 
equivalent per se offense).
    Therefore, for this BIL option, a technology would need to 
passively and accurately detect whether the BAC of a driver of a motor 
vehicle is equal to or greater than .08 g/dL. Typically, BAC is 
measured as the weight of alcohol in a certain volume of blood 
(expressed in g/dL). Accurate measurement of BAC typically requires a 
driver's blood being drawn by a phlebotomist and sent to a lab where a 
medical laboratory scientist prepares samples and performs tests using 
machines known as analyzers.
    To measure BAC passively and accurately in a motor vehicle setting 
would therefore require alternative detection methods. The DADSS 
breath-based sensor, discussed above, can measure driver breath samples 
at the start of the trip or during the drive to measure driver BrAC. 
The DADSS touch-based sensor has the potential to be located on the 
ignition push-button or on the steering wheel. Similarly, it will be 
designed to take measurements at the start of the trip, or during the 
drive, in the case of the steering wheel application.
    Previous research through the DADSS program has established that 
the alcohol measurements from breath and touch sensors can be 
consistent, reproducible, and correlate well with traditional blood and 
breath alcohol measurements.\190\ As noted, the prototypes under 
development for a passive, accurate breath-based sensor \191\ are 
planned for design completion in 2024 and a passive, accurate touch-
based sensor \192\ for 2025, with additional time needed to integrate 
systems in vehicle models and conduct verification and validation. 
Preliminary estimates suggest that manufacturers will need at least 18-
24 months to integrate the technology into vehicles.\193\
---------------------------------------------------------------------------

    \190\ Lukas S.E., Ryan E., McNeil J., Shepherd J., Bingham L., 
Davis K., Ozdemir K., Dalal N., Pirooz K., Willis M., Zaouk A. 2019. 
Driver alcohol detection system for safety (DADSS)--human testing of 
two passive methods of detecting alcohol in tissue and breath 
compared to venous blood. Paper Number 19-0268. Proceedings of the 
26th International Technical Conference on the Enhanced Safety of 
Vehicles.
    \191\ The breath sensor is being designed to capture a driver's 
naturally exhaled breath upon first entering the vehicle.
    \192\ The touch sensor is being designed to be imbedded in 
something that the driver is required to touch to operate the 
vehicle such as the push-to-start button or the steering wheel rim.
    \193\ When might the DADSS technology be in U.S. cars and 
trucks?--DADSS--Driver Alcohol Detection System. (last accessed 3/
20/2023), available at https://dadss.org/news/updates/when-might-the-dadss-technology-be-in-u-s-cars-and-trucks/.
---------------------------------------------------------------------------

    Therefore, a current limitation of this option is the fact that 
NHTSA is not aware of a passive and accurate .08 g/dL BAC detection 
technology available for production vehicles today, and hence the 
timeframe for fleet implementation may be an issue.
Questions on Technologies Aimed at Passively and Accurately Detecting 
Whether the BAC of a Driver of a Motor Vehicle Is Equal to or Greater 
Than .08 g/dL
    2.1. In a follow-up to NHTSA's technology scans, NHTSA seeks any 
new information on technologies that can passively and accurately 
detect whether the BAC of a motor vehicle driver is equal to or greater 
than .08 g/dL.
    2.2. Although the legal thresholds for DUI/DWI laws focus on BAC/
BrAC, BAC/BrAC are typically not used in isolation by law enforcement 
to determine impairment. BrAC/BAC may provide additional evidence of 
impairment after an officer has observed driving behavior, the 
appearance of the driver (e.g., face flushed, speech slurred, odor of 
alcoholic beverages on breath), the behavior of the driver, and any 
statements the driver has made about alcohol or drug use. Additionally, 
an officer may have administered the Standard Field Sobriety Test. 
Considering this, should regulatory options use BAC/BrAC in isolation 
to determine whether drivers are above the legal limit? If so, why?

[[Page 852]]

    2.3. Are commenters concerned about using the legal limit (.08 g/
dL) when there are indications that some individuals exhibit 
intoxication that would impact driving at lower or higher levels, 
depending on a number of factors discussed in the introduction? Why or 
why not? Might drivers with a BAC greater than 0 g/dL but less than .08 
g/dL interpret the fact that their vehicle allows them to drive as an 
indication that it is safe for them to drive after drinking? If so, are 
there ways to mitigate this possible unintended consequence?
    2.4. Given the quantifiable positive impacts on highway safety that 
Utah has experienced since lowering its BAC thresholds to .05 g/dL, 
should NHTSA consider setting a threshold lower than .08 g/dL?
    2.5. Is a BrAC detection that correlates to a BAC of .08 g/dL or 
above sufficiently accurate?
    2.6. Would a standard that allows or requires systems that 
approximate BAC using BrAC (at any concentration) meet the Safety Act's 
requirement that standards be objective? Would the technology detect 
BAC?
    2.7. NHTSA is seeking input on how a .08 g/dL BAC detection test 
procedure could be developed and executed in a FMVSS. For example, are 
dosed humans required or would a test device to simulate human dosing 
be required? What type of accuracy could be attained? Would static test 
procedures accurately simulate dynamic performance? In a BrAC 
evaluation, how would variance in vehicle cabin volume be accounted 
for?
    2.8. What precision/accuracy should BAC detection technology be 
required to meet? Should any precision/accuracy requirement be fixed at 
a final rule stage, or should it become progressively more stringent 
over time with a phase-in?
    2.9. For a BAC-based sensor, NHTSA seeks comment on when during a 
vehicle's start-up sequence an impairment detection measurement should 
occur. For example, should an initial measurement of BAC/BrAC be 
required upon vehicle start-up, or before the vehicle is put into 
drive, and why? What is a reasonable amount of time for that reading to 
occur?
    2.10. NHTSA recognizes that ongoing detection would be necessary to 
identify if a driver reaches an impairment threshold only after 
commencing a trip, particularly if drinking during a drive. NHTSA seeks 
comment on whether BAC/BrAC measurements should be required on an 
ongoing basis once driving has commenced, and, if so, with what 
frequency, and why. Further, would a differentiation of the 
concentration threshold between initial and ongoing detection be 
recommended and why?
    2.11. NHTSA requests comments on operational difficulties in using 
touch-based sensing (e.g., consumer acceptance in colder climates when 
gloves may interfere) or in using breath-based sensing (e.g., 
mouthwash, vaping, alcohol-drenched clothing, or other false positive 
indicators).
    2.12. What can be done to mitigate physical destruction and misuse? 
Examples may include having a sober passenger press the touch sensor or 
breathe toward the breath sensor. If mitigations exist, how might these 
mitigations impact the effectiveness of alcohol detection systems?
    2.13. Are there cybersecurity threats related to impairment 
detection systems? If so, what are they? Are there potential 
vulnerabilities that might allow outside actors to interfere with 
vehicles' impairment detection systems or gain unauthorized access to 
system data? How can cybersecurity threats be mitigated? Are there 
impairment detection methods or technologies that are less vulnerable 
than others?
    2.14. What temporal considerations should NHTSA include in any 
performance standards it develops (i.e., should NHTSA specify the 
amount of time a system needs to make a first detection upon startup 
before it will enable driving)? What amount of time is reasonable?
c. A Combination Detection Approach: Passively Monitor the Performance 
of a Driver of a Motor Vehicle To Accurately Identify Whether That 
Driver May Be Impaired and Passively and Accurately Detect Whether the 
BAC of a Driver of a Motor Vehicle Is Equal to or Greater Than .08 g/dL
    This regulatory option combines the prior two. The combination of 
driver impairment detection (e.g., using camera-based driver monitoring 
and other vehicle sensors) and .08 g/dL BAC detection may provide more 
opportunity to capture alcohol-impaired drivers at the start of the 
trip as well as those that have elevated BAC during the drive. It 
further may have the potential to help mitigate false positive 
detections by providing multiple detection methods.
    In a NHTSA research study,\194\ all the reviewed hybrid systems 
used camera-based DMS measures in addition to vehicle kinematic or 
physiological measures. The study further suggested that augmentation 
of camera-based measures with other measures is expected to be a trend 
in driver state monitoring systems, particularly those that measure 
alcohol impairment. Specifically, NHTSA's research study found sensors 
from two vehicle manufacturers, Toyota and Nissan, that used variables 
that have been found sensitive to alcohol impairment, including eye and 
eye closure measures, sweat, and BrAC. However, neither is on the 
market.
---------------------------------------------------------------------------

    \194\ Prendez, D.M., Brown, J.L., Venkatraman, V., Textor, C., 
Parong, J., & Robinson, E. (in press). Assessment of Driver 
Monitoring Systems for Alcohol Impairment Detection and Level 2 
Automation. National Highway Traffic Safety Administration.
---------------------------------------------------------------------------

    Therefore, a current limitation of this option is the fact that 
NHTSA is not aware of a passive and accurate .08 g/dL BAC detection 
technology available for production vehicles, as discussed in the 
previous section, and hence the timeframe for implementation may be a 
limiting factor.
Questions on Technologies Aimed at a Combination of Driver Impairment 
and BAC Detection
    3.1. In light of the technology development needs to both passively 
and accurately detect .08 g/dL BAC and passively monitor the 
performance of a driver of a motor vehicle to accurately identify 
whether that driver may be impaired, are there interim strategies NHTSA 
should pursue?
    3.2. If an alcohol impairment detection system utilizes both BAC 
detection and DMS components, which DMS metrics best complement a BAC 
system to ensure accuracy, precision, and reliability?
    3.3. One possible benefit of a hybrid approach is that a camera 
system could help prevent intentional defeat of BAC/BrAC sensors. For 
example, when a driver presses a touch sensor to measure BAC, a camera 
using machine vision could verify that it is the driver and not a 
passenger who touches the sensor. Could the camera provide additional 
benefits against defeating the system?
    3.4. NHTSA is considering a phased approach to addressing alcohol 
impairment. The agency is concerned about false positives. Effectively, 
this approach could have a first phase that aims to address alcohol-
impaired drivers with a BAC of .15 g/dL or higher, where an alcohol 
sensor could have better accuracy in detecting alcohol-impairment, in 
combination with a camera-based DMS and/or other vehicle technologies. 
By improving the BAC detection accuracy, it may gain more consumer 
acceptance by lowering the false positive rate (i.e., the chance that 
someone with a BAC below .08 g/dL is incorrectly identified as alcohol-

[[Page 853]]

impaired by a vehicle system). This would also target the drivers with 
the highest levels of impairment. With time and accuracy improvement, a 
second phase could be pursued to achieve the .08 g/dL BAC accuracy 
needed to comply with BIL. NHTSA therefore seeks comment on the 
viability of this regulatory approach. Is a BAC of .15 g/dL the right 
limit to phase in?
    3.4. An option could also be a system with primary and secondary 
indicators within a driver impairment algorithm. For example, a system 
could incorporate a zero or low (.02 g/dL) tolerance BAC detection 
technology to initially sense whether alcohol is present in the 
vehicle. This would serve to ``wake up'' a driver impairment algorithm. 
Since this could be hand sanitizer or alcohol on a person's clothing, a 
second confirmation of driver impairment from a driver monitoring 
system would be needed. Driver performance measures, such as eye gaze, 
lane weaving, etc. would be the primary indicators of impairment and 
utilize evidence of alcohol as a supplementary indicator for alcohol 
impairment. Given this approach, would such a system allow a vehicle to 
better distinguish between alcohol impairment and other forms of 
impairment that have similar indicators (i.e., the percentage of eyelid 
closure can be an indicator of both drowsy and drunk driving)? NHTSA 
notes that it has not identified any passive, production-ready, 
alcohol-impaired driver detection technology capable of accurate 
detection at .02 g/dL and seeks comment on the status of such 
technology.
3. Proposed Vehicle Interventions Once Driver Impairment or BAC Is 
Detected
    Once drunk driving or driver impairment is detected by a vehicle, 
the question becomes--what does the vehicle do with that information? 
BIL states that advanced drunk and impaired driving technologies 
include the ability to ``prevent or limit'' motor vehicle operation. 
There are a variety of strategies to prevent or limit operations that 
have been under research or have been implemented in production 
vehicles, such as the ignition interlocks discussed above.\195\ Others 
range from not allowing the vehicle to move out of park (transmission 
interlocks), to warnings (used perhaps as a supplement to an 
intervention approach), to slowing or stopping the vehicle (in lane, or 
on the shoulder or right-most lane). There are also many considerations 
involved in selecting appropriate interventions, given the timing of 
impairment detection (i.e., prior to the start of driving or during 
driving). Additionally, interventions appropriate for drunk driving may 
be different than those employed for other forms of driver impairment. 
For example, drunk drivers may respond more slowly to warnings than a 
sober but drowsy driver. Additionally, repeatedly warning a driver 
beyond the level or frequency that generates a positive reaction could 
lead to consumer annoyance and defeat efforts. NHTSA seeks to balance 
these concerns.
---------------------------------------------------------------------------

    \195\ NHTSA notes that nothing in this document is intended to 
replace ignition interlocks used as a sanction for impaired driving 
offenses.
---------------------------------------------------------------------------

a. Prohibiting Driving at Start of the Trip
    Ideally, once a defined level of alcohol has been accurately sensed 
from an impaired driver by vehicle technology, that individual would be 
prohibited from driving the vehicle. For example, this prohibition 
could be accomplished through an ignition or transmission shift 
interlock for an internal combustion engine vehicle. The vehicle could 
be put in accessory mode, and not able to move. Prohibiting an impaired 
driver from driving the vehicle at the start of a trip targets the 
largest number of alcohol-impaired fatalities.
    The .08 g/dL BAC touch-sensor and/or breath-sensor detection 
technologies, which can ideally take immediate BAC measurements, are 
better suited for prohibiting driving at the start of the trip versus 
others that require a temporal measure of driver performance. While the 
technology readiness of the DADSS technologies to provide accurate .08 
g/dL BAC detection is still undergoing research and development at this 
time, there are still many challenges associated with this prevention 
method that should be considered if it were to become a viable 
regulatory option.
    Assuming an accurate detection technology is fully developed 
(including a standardized method for testing), NHTSA would have to 
consider the overall effectiveness of the intervention strategy and the 
overall cost (economic, societal, etc.). Some considerations would, 
among other things, include: consumer acceptance; defeat strategies; 
unintended consequences of immobilizing a vehicle; need for an 
emergency override; and time between disablement and re-enablement. 
NHTSA is seeking feedback on the following questions.
Questions on Prohibiting Driving at the Start of the Trip
    4.1. How would an alcohol-impaired person react to their vehicle 
not starting, and how can/should this be considered? Would some 
individuals decide to walk to their destination in the road, increasing 
their risk of being hit by another vehicle? Would they get a sober 
person to start their vehicle and then take over the driving task 
themselves? Are there countermeasures to discourage this practice by 
shutting down the vehicle for a period of time after two failed 
attempts? NHTSA seeks comment on potential research designs to develop 
better information in this area.
    4.2. What are the pros/cons of an ignition interlock as opposed to 
a transmission interlock prevention method for internal combustion 
engine vehicles? Is one superior to the other? Should both be 
acceptable compliance options if considered for an FMVSS? How would 
this differ for electric vehicles and what issues specific to electric 
vehicles should NHTSA consider?
    4.3. NHTSA seeks comment on any adverse consequences of an impaired 
driver being unable to drive his/her vehicle. For example, this could 
result in an alcohol-impaired person being stranded late at night for 
hours and susceptible to being a victim of crime or environmental 
conditions (e.g., weather). Or an alcohol-impaired camper may need to 
use his/her vehicle to escape from a rapidly approaching wildfire or 
environmental conditions (weather). How often would such incidences 
expect to occur (assuming full fleet implementation)? Are there logical 
strategies for mitigating the negative effects? What if the vehicle 
owner wishes to drive their vehicle on private land (i.e., not on 
public roads)?
    4.4. Given the previous examples, should there be an override 
feature for emergencies? Should the maximum speed of the vehicle be 
limited during override? How could an override feature be preserved for 
extreme situations and not used routinely when alcohol-impaired?
    4.5. If a system detects alcohol impairment prior to the start of a 
trip and an interlock is activated, should retest(s) be allowed, at 
what elapsed time interval(s), and why? NHTSA especially seeks comment 
on test/data analysis methods for determining an optimal retest 
interval strategy. Finally, should data be recorded on the vehicle if 
retesting is permitted?
b. Vehicle Warnings Once Impairment Detected (On-Road)
    In addition to driver impairment being detected and prevented at 
the start of a trip, driver impairment can be monitored over time 
during the drive. Detecting that a driver is alcohol-impaired mid-trip 
is obviously a less

[[Page 854]]

desirable scenario (than detecting that a driver is impaired via an 
ignition/transmission interlock) since an alcohol-impaired driver may 
have the unfortunate opportunity to get in a crash before the driver 
impairment is detected. However, this type of strategy may mitigate a 
larger group of driver-impairment fatalities, not just alcohol, and 
vehicle warnings could be relatively low cost.
    That said, there are many challenges associated with this 
intervention that should be addressed for it to become a viable 
regulatory option. Assuming an accurate detection technology was fully 
developed (including a standardized method for testing), NHTSA would 
have to consider the overall effectiveness of warnings as an 
intervention strategy against the various driver impairments, and the 
overall cost (e.g., economic, societal). Some of the considerations 
would, among other things, include: consumer acceptance, defeat 
strategies, unintended consequences of warnings, need for an 
incapacitation sensor, etc. NHTSA is seeking feedback on the following 
questions.
Questions on Vehicle Warnings Once Impairment Is Detected
    5.1. NHTSA is aware of many vehicle manufacturers using visual/
auditory warnings (e.g., a coffee cup icon) and encouraging drivers to 
take a break from the driving task. There are also visual/auditory/
haptic warnings to identify distracted driving or hands off the 
steering wheel while Level 2 driving automation systems are engaged. 
NHTSA is interested in any studies to support the effectiveness of 
these warnings, including designing against defeat strategies. NHTSA 
also seeks comment and studies on whether similar warnings may be 
effective for alcohol-impaired or incapacitated drivers or would 
additional interventions be needed. The system attributes that enhance 
a system's effectiveness are of particular interest to NHTSA. Are there 
any unintended consequences from these warnings? If so, what are they?
    5.2. NHTSA's research suggested that indicators of alcohol 
impairment are often also potential indicators of other conditions, 
such as drowsiness. Hence, the preventative measures of each condition 
may need to be addressed differently. For example, distracted drivers 
can quickly return their attention to the driving task, and drowsy 
drivers can recover with adequate rest as an intervention, but drunk 
drivers may need a much longer recovery time as alcohol 
metabolizes.\196\ NHTSA therefore requests research and information on 
what warning strategy would effectively encourage both drivers that are 
alcohol-impaired and drivers that have a different impairment to 
improve their performance in the driving task (e.g., by resting, 
getting a caffeinated beverage)? Or is there research to support that a 
warning would only be effective for a distracted driver or a drowsy 
driver, but may aggravate an alcohol-impaired driver? Are there other 
adverse consequences from using warnings to address multiple types of 
impairment? If so, what are they?
---------------------------------------------------------------------------

    \196\ Hancock, P.A. (2017). Driven to distraction and back 
again. In Driver Distraction and Inattention (pp. 9-26). CRC Press.
---------------------------------------------------------------------------

    5.3. NHTSA seeks comment on how manufacturers balance multiple 
alerts in response to different impairment detections. Given the many 
forms of impairment, if systems are developed that can distinguish 
effectively between alcohol impairment and other forms, is it 
practicable to employ a variety of different responses? Will multiple 
warnings (auditory, visual, or haptic) or other interventions for 
different forms of impairment only serve to confuse drunk drivers and 
lessen effectiveness for responses to drunk driving?
    5.4. NHTSA seeks comment on how warnings, especially multiple 
warnings, may impact drivers with an auditory or sensory processing 
disability. Would multiple warnings distract some drivers?
    5.5. NHTSA seeks comment on how systems react if the drowsy driver 
(or other inattentive or impaired driver) does not respond to warnings? 
What types of warning escalation strategies (timing, perceived urgency, 
and frequency) are used in industry and are they consistent among 
manufacturers?
c. Vehicle Interventions Once Impairment Is Detected (On-Road)
    The most challenging countermeasure for preventing drunk and 
impaired driving fatalities is implementing vehicle interventions while 
the vehicle is in motion. There are a variety of strategies that have 
been under research, in development, or in production. Some are 
discussed below:
    Limp Home Mode--once impairment (or incapacitation) is detected, 
the vehicle speed is reduced to a lower speed for a given amount of 
time. Adaptive cruise control with a long following gap setting could 
be turned on to prevent a forward crash with other vehicles. Systems 
may provide the driver a warning that the driver needs to leave the 
highway.
    Stop in Lane--depending upon the vehicle manufacturer, the vehicle 
reduces speed and ultimately stops in the lane after a given time 
period of unresponsiveness of the driver (typically when the Level 2 
driving automation system is engaged), putting on emergency flashers 
and unlocking the doors for easier entry into the vehicle. This 
presents a new hazard to motorists approaching the stopped vehicle, and 
a different kind of hazard for occupants of the stopped vehicle (i.e., 
the original hazard was the drunk driver, but now the hazard is 
potentially being hit by other motorists). Some SAE Level 2 driving 
automation systems make use of this feature if the driver becomes 
unresponsive and some also can call for assistance.
    Pull over to the Slow Lane (Right Lane) or Shoulder--some vehicle 
manufacturers have introduced more advanced concept or production 
vehicles that can pull over to the side of the road or into the ``slow 
lane'' once driver impairment (or incapacitation) is detected when 
Level 2 systems are engaged.\197\ This requires the vehicle to be 
equipped with lane-changing capability, where a vehicle needs to be 
able to understand whether there are vehicles or other road users in 
(or approaching) its blind spot in order to make a lane change. Modern 
vehicles increasingly have the technology to detect lane lines and 
blind spots, and to automate lane changes, under certain circumstances.
---------------------------------------------------------------------------

    \197\ https://www.forbes.com/wheels/advice/automatic-emergency-stop-assistance/.
---------------------------------------------------------------------------

    For example, in 2019, media reports suggested a Volvo system would 
detect drunkenness, drowsiness, or distraction,\198\ and interventions 
could include limiting the speed of the vehicle or slowing it down and 
safely parking the car.\199\ The agency believes this Volvo system will 
not be available on production vehicles in the U.S. until 2024.\200\ 
The agency will evaluate technologies as they become available.
---------------------------------------------------------------------------

    \198\ https://www.motortrend.com/news/volvo-drunk-driving-distracted-cameras-sensors-safety/.
    \199\ https://www.theverge.com/2019/3/20/18274235/volvo-driver-monitoring-camera-drunk-distracted-driving.
    \200\ https://www.volvocars.com/us/cars/ex90-electric/.
---------------------------------------------------------------------------

Questions on Vehicle Interventions Once Detected (On-Road)
    6.1. What types of vehicle interventions are in use today for SAE 
Level 2 driving automation systems when the system detects the driver 
is incapacitated? What prevents their use

[[Page 855]]

in being coupled with driver impairment or BAC detection technology? 
What is the feasibility of using these interventions without engaging 
Level 2 driving automation?
    6.2. Stopping in the middle of the road could introduce new motor 
vehicle safety problems, including potential collisions with stopped 
vehicles and impaired drivers walking in the roadway. What strategies 
can be used to prevent these risks? How are risks different if the 
vehicle stops on the shoulder of the road? What preventative measures 
could be implemented for vehicles approaching the stopped vehicle? What 
are the risks to occupants involved in those scenarios?
    6.3. What is the minimum sensor and hardware technology that would 
be needed to pull over to a slower lane or a shoulder and the cost?
Questions on Other Approaches To Reduce Impaired Driving
    7.1. As vehicle technologies continue to develop with potential to 
reduce impaired driving, what steps or approaches should NHTSA consider 
now, including potential partnerships with States or other entities?
    7.2. Which best practices have States found most effective in 
reducing impaired driving? Have States found approaches such as sharing 
information about drunk driving convictions to be helpful in reducing 
impaired driving?

V. Summary of Other Efforts Related to Impaired Driving

    NHTSA is aware of several other ongoing efforts by external 
entities to establish performance requirements for systems to detect 
alcohol impairment or otherwise influence the development of such 
performance requirements.
    SAE International has developed SAE J3214, a ``Breath-Based Alcohol 
Detection System'' standard. This standard focuses on directed breath 
zero-tolerance systems, which are systems that look for any level of 
alcohol via the driver's BrAC and require that a driver direct a breath 
toward a device for measurement. The standard was published on June 27, 
2021.\201\
---------------------------------------------------------------------------

    \201\ https://www.sae.org/standards/content/j3214_202101/.
---------------------------------------------------------------------------

    The various New Car Assessment Programs (NCAPs) from around the 
world are also considering protocols for detection of driver state and 
system warning or intervention.\202\ Euro NCAP focuses on DMS and while 
its assessment protocol mentions impaired driving, the actual 
assessment focuses only on distraction, fatigue (i.e., drowsiness), and 
unresponsive drivers.\203\ Euro NCAP currently describes no specific 
assessment for alcohol impairment. Euro NCAP Vision 2030 states that 
expanding the program's scope of driver impairment by adding specific 
detection of driving under the influence is a priority for the mid-
term: ``. . . [A] key real-world priority for the midterm therefore is 
to expand the scope of driver impairment adding specific detection of 
driving under the influence and sudden sickness with advanced vision 
and/or biometric sensors and introducing more advanced requirements for 
risk mitigation functions.'' \204\ Mid-term is not defined in the text 
of the document, but a graphic indicates that 2032 is Euro NCAP's 
targeted timeline. Even so, NHTSA is monitoring Euro NCAP's efforts to 
see if they might be leveraged in this rulemaking activity. NHTSA's 
understanding is that Australasian NCAP is considering protocols like 
Euro NCAP. Additionally, NHTSA has sought comment on the inclusion of 
DMS and alcohol detection systems in U.S. NCAP.\205\ NHTSA is in the 
process of considering all comments received and drafting a final 
decision that will establish a roadmap that includes plans to upgrade 
U.S. NCAP in phases over the next several years. Other organizations, 
like Consumer Reports \206\ and the Insurance Institute for Highway 
Safety (IIHS),\207\ include DMS in their programs. Finally, NHTSA is 
aware of and following the work of the Impairment Technical Working 
Group that is intended to assist with the implementation of advanced 
impaired driving technology.\208\ The group is co-chaired by members of 
the Johns Hopkins Center for Injury Research and Policy at the John 
Hopkins Bloomberg School of Public Health and MADD. The Impairment 
Technical Working Group formed with the goal of ``identifying efficient 
and effective approaches for implementing driver impairment prevention 
technology in new cars.'' The Impairment Technical Working Group is one 
of many groups or organizations interested in influencing this 
rulemaking proceeding. On April 18, 2023, the Impairment Technical 
Working Group issued a short ``Views Statement'' that included three 
recommendations for implementing advanced impaired driving 
technology.\209\ These three recommendations are largely duplicative of 
the mandate in BIL but deviate slightly in that they explicitly request 
that multiple impairment types be included through this rulemaking 
(i.e., not limited to alcohol impairment). Also, the group's three 
recommendations, when read together, describe the group's preference 
for the third (i.e., hybrid) option in BIL.
---------------------------------------------------------------------------

    \202\ NHTSA's New Car Assessment Program (NCAP) provides 
comparative information on the safety performance of new vehicles to 
assist customers with vehicle purchasing decisions and to encourage 
safety improvements. In addition to star ratings for crash 
protection and rollover resistance, the NCAP program recommends 
particular advanced driver assistance systems (ADAS) technologies 
and identifies the vehicles in the marketplace that offer the 
systems that pass NCAP performance test criteria for those systems.
    \203\ https://cdn.euroncap.com/media/70315/euro-ncap-assessment-protocol-sa-safe-driving-v101.pdf.
    \204\ https://cdn.euroncap.com/media/74468/euro-ncap-roadmap-vision-2030.pdf.
    \205\ 87 FR 13452 (March 9, 2022), available at https://www.federalregister.gov/documents/2022/03/09/2022-04894/new-car-assessment-program.
    \206\ Driver Monitoring Systems Can Help You Be Safer on the 
Road--Consumer Reports.
    \207\ IIHS creates safeguard ratings for partial automation.
    \208\ U.S. Senator Ben Ray Luj[aacute]n (2022) Luj[aacute]n, 
Advocates Announce Technical Working Group to Implement Advanced 
Impaired Driving Prevention Technology. June 14, 2022. https://www.lujan.senate.gov/newsroom/press-releases/%EF%BF%BClujan-advocates-announce-technical-working-group-to-implement-advanced-impaired-driving-prevention-technology/.
    \209\ https://advocacy.consumerreports.org/research/technical-working-group-on-advanced-impaired-driving-prevention-technology-views-statement-on-implementing-driver-impairment-prevention-technology/.
---------------------------------------------------------------------------

VI. Privacy and Security

    In considering next steps, NHTSA is aware of the need for 
comprehensive analysis of the privacy considerations that are relevant 
to developing performance requirements for systems that would identify 
and prevent individuals who are intoxicated from driving. Per the E-
Government Act of 2002 and internal DOT policies and procedures, NHTSA 
intends to conduct a privacy threshold analysis (PTA) to determine 
whether the agency should publish a draft Privacy Impact Assessment 
(PIA) concurrent with its issuance of a regulatory proposal that would 
establish performance requirements for advanced impaired driving 
technology. Although NHTSA welcomes privacy-related comments in 
response to this advance notice of proposed rulemaking, the agency 
expects that any future regulatory proposal and any accompanying draft 
PIA would provide the public with more detailed analysis necessary to 
evaluate potential privacy risks and proposed mitigation controls 
associated with advanced impaired driving technology.
    NHTSA also intends to consider closely any potential security 
implications that are relevant to developing performance requirements

[[Page 856]]

for systems that would identify and prevent individuals who are 
intoxicated from driving. NHTSA requests comments on privacy and 
security issues that the agency should consider while developing its 
proposal. NHTSA acknowledges that many of the answers to these 
questions would be design-specific, and thus, expects that commenters 
might provide generalized input now with more specific input at the 
proposal stage.

Questions About Privacy and Security Considerations

    8.1. NHTSA understands that personal privacy considerations are 
critical to the design of any system that monitors driver behavior or 
condition. Such considerations are also one component of consumer 
acceptance of systems described in this advance notice of proposed 
rulemaking. NHTSA seeks comment on privacy considerations related to 
use and potential storage of data by alcohol and impairment detection 
systems and how best to preserve driver and passenger personal privacy. 
Are there strategies or requirements (e.g., prohibitions on camera-
based DMS from recording certain types of imagery) to protect privacy?
    8.2. Given the potential for different privacy impacts associated 
with different types of systems and information used in those systems, 
how should NHTSA weigh the different potential privacy impacts? For 
example, how should accuracy be weighed against privacy? Do certain 
metrics result in less privacy impact than others while providing the 
same or more accuracy? If so, how?
    8.3. What performance-based security controls should NHTSA consider 
including in its potential performance requirements for advanced 
impaired driving technology? Are there any industry or voluntary 
standards specific to these technologies that NHTSA should consider? If 
not, which standards do commenters believe would be most appropriate 
for these systems to comply with and why?
    8.4. Are there any additional security vulnerabilities that these 
systems would present that do not already exist in modern vehicles 
(e.g., passenger vehicles that are equipped with various technologies 
such as automatic emergency braking, lane keeping support, and others)? 
If so, what needs to be done to mitigate those potential 
vulnerabilities?
    8.5. What suggestions do commenters have regarding how the agency 
should go about educating the public about security and privacy aspects 
of advanced impairment and drunk driving detection technology?

VII. Consumer Acceptance

    As discussed in the authority section of this document, consumer 
acceptance is one component of practicability that NHTSA must consider 
when developing a FMVSS. NHTSA is aware that a combination of 
misinformation related to advanced drunk and impaired driving 
technologies, and misbelief that there exists a right to drive while 
drunk \210\ have resulted in some individuals believing that this 
rulemaking is pursuing a course of action that might unduly infringe 
upon their rights. NHTSA has received correspondence that leads the 
agency to believe that some individuals believe that they not only have 
a right to drive,\211\ but a right to drive while intoxicated by 
alcohol.\212\ As NHTSA has said before, driving is a privilege, not a 
right.\213\ These examples highlight potential consumer acceptance 
challenges, but not all such instances would be considered legitimate 
or sufficient to undermine the practicability prong of the Safety Act.
---------------------------------------------------------------------------

    \210\ https://www.rollingstone.com/culture/culture-news/tiktok-drunk-driving-booze-cruise-gang-alcohol-1234588210/. NHTSA would 
believe this trend was entirely edgy satire if it had not received 
correspondence that indicates that some genuinely believe they have 
a right to drive drunk. ``Few would react the same to someone 
announcing they occasionally text while driving as they would to 
admitting to the occasional booze cruise while statistically there 
isn't much difference in added danger.'' NHTSA agrees that both 
texting while driving and driving while intoxicated are dangerous 
activities that put the safety of the public at risk.
    \211\ NHTSA has said before that driving is a privilege, not a 
fundamental right. See https://www.nhtsa.gov/open-letter-driving-
public#:~:text=Driving%20is%20a%20privilege%2C%20and,to%20protect%20a
ll%20of%20us. Obeying the rules of the road is a prerequisite for 
the privilege of driving. See https://www.nhtsa.gov/teen-driving/parents-hold-keys-safe-teen-driving.
    \212\ Assertions that drunk driving is acceptable, or even a 
right, are not new. This 1984 opinion piece in the New York Times 
provides an example of someone who thought he was entitled to drive 
drunk, seemingly because he hadn't killed or injured anyone yet. See 
https://jalopnik.com/check-out-this-pro-drunk-driving-op-ed-the-nyt-publishe-1847408294; https://www.nytimes.com/1984/06/03/nyregion/long-island-opinion-drinking-and-driving-can-mix.html. Please visit 
the docket for a letter NHTSA received that appears to assert that 
some individuals should be permitted to drive drunk.
    \213\ Id.
---------------------------------------------------------------------------

    Additionally, NHTSA is encouraged by the results of a recent study 
conducted by researchers with Johns Hopkins Bloomberg School of Public 
Health and published in the Journal of the American Medical Association 
Network Open.\214\ This study provides survey results from a relatively 
small-scale study with the objective of measuring public support for 
driver monitoring and lockout technologies. The survey contained two 
parts, one part querying whether participants supported or opposed 
``the recent action by Congress to require drunk driving prevention in 
all new vehicles.'' The second part ask participants to indicate their 
level of agreement regarding six different warning or lockout 
technologies. A five-point scale was used for responses to both parts 
of the survey (strongly agree to strongly disagree). The primary 
findings of the study were that support for the congressional mandate 
on vehicle impairment detection technology was high, with 63.4 percent 
of respondents supporting the law (survey part 1.) For survey part 2, 
the author reported that 64.9 percent of respondents either agreed or 
strongly agreed with the statement, ``All new cars should have an 
automatic sensor to prevent the car from being driven by someone who is 
over the legal alcohol limit.'' Results for neutral and negative 
responses were only reported in graphical form, not exact measurements 
(i.e., reported percentages and confidence intervals).
---------------------------------------------------------------------------

    \214\ https://jamanetwork.com/journals/jamanetworkopen/fullarticle/2803962?utm_source=For_The_Media&utm_medium=referral&utm_campaign=ftm_links&utm_term=042023.
---------------------------------------------------------------------------

    Safety is the predominant consideration when evaluating potential 
vehicle performance requirements designed to combat drunk driving 
effectively. However, the public may not realize estimated associated 
benefits if vehicle performance requirements and the technologies that 
meet them are not designed to differentiate with precision drivers who 
are impaired from those who are not, minimize interventions to those 
necessary to achieve results, and conform with principles of human 
factors engineering and design.

Question About Consumer Acceptance

    9.1. NHTSA requests comment on legitimate consumer acceptance 
issues related to advanced drunk and impaired driving technologies and 
suggestions for how the agency might be able to craft future proposed 
performance requirements to remedy any consumer acceptance issues.

VIII. General Questions for the Public

    In the preceding preamble, NHTSA seeks comment on a variety of 
complex issues related to establishing a new FMVSS to require that 
passenger motor vehicles be equipped with advanced drunk and impaired 
driving prevention technology. These questions are numbered and 
included throughout the preamble text in the appropriate sections. But 
not all questions fit neatly under the preceding titles. As such,

[[Page 857]]

NHTSA also seeks comment on the remaining questions listed below.
    10.1. NHTSA seeks comment on any reliability or durability 
considerations for alcohol impairment detection technology that may 
impact functionality over its useful life.
    10.2. NHTSA requests any information regarding the final installed 
costs, including maintenance costs, of impairment detection systems.
    10.3. Should NHTSA propose a standardized telltale \215\ or 
indicator \216\ (or set of telltales) indicating that impairment has 
been detected (and/or that vehicle systems have been limited in 
response)? Are there standardized industry telltales or indicators 
already developed for this sort of system that NHTSA should consider?
---------------------------------------------------------------------------

    \215\ Telltale means an optical signal that, when illuminated, 
indicates the actuation of a device, a correct or improper 
functioning or condition, or a failure to function.
    \216\ Indicator means a device that shows the magnitude of the 
physical characteristics that the instrument is designed to sense.
---------------------------------------------------------------------------

    10.4. NHTSA broadly seeks comment on how to best ensure that 
manufacturers have the flexibility to develop more effective impairment 
detection technology while preserving a minimum level of accuracy and 
reliability.
    10.5. Should NHTSA consider establishing a requirement that allows 
a vehicle's BAC detection threshold to be adjusted downward based on 
the BAC thresholds of local jurisdictions or fleet owners? Note, this 
technology would not be intended or designed to replace a State's 
enforcement of its own statutes.
    10.6. Earlier in this document, NHTSA noted that progress in 
reducing drunk driving resulting from many behavioral safety campaigns 
has plateaued. Should NHTSA devote more of its behavioral safety 
resources towards those programs and efforts that address underlying 
contributors to alcohol use disorder, including drunk driving, like 
mental health conditions? Are there effective behavioral safety 
campaigns or tactics NHTSA is not using?

IX. Rulemaking Analyses

A. Executive Order 12866, Executive Order 13563, Executive Order 14094, 
and DOT Regulatory Policies and Procedures

    The agency has considered the impact of this ANPRM under Executive 
Orders (E.O.) 12866, 13563, 14094 and the Department of 
Transportation's regulatory policies and procedures. This action has 
been determined to be significant under E.O. 12866 (Regulatory Planning 
and Review), supplemented and reaffirmed by E.O. 13563 and amended by 
E.O. 14094, and DOT Order 2100.6A, ``Rulemaking and Guidance 
Procedures.'' It has been reviewed by the Office of Management and 
Budget under E.O. 12866. E.O. 12866 and 13563 require agencies to 
regulate in the ``most cost-effective manner,'' to make a ``reasoned 
determination that the benefits of the intended regulation justify its 
costs,'' and to develop regulations that ``impose the least burden on 
society.'' Additionally, E.O. 12866 and 13563 require agencies to 
provide a meaningful opportunity for public participation, and E.O. 
14094 affirms that regulatory actions should ``promote equitable and 
meaningful participation by a range of interested or affected parties, 
including underserved communities.'' We have asked commenters to answer 
a variety of questions to elicit practical information about the 
approach that best meets these principles and the Safety Act and any 
relevant data or information that might help support a future proposal.

B. Privacy Act

    Anyone can search the electronic form of all documents received 
into any of NHTSA's dockets by the name of the individual submitting 
the document (or signing it, if submitted on behalf of an association, 
business, labor union, etc.). As described in the system of records 
notice DOT/ALL 14 (Federal Docket Management System), which can be 
reviewed at https://www.transportation.gov/individuals/privacy/privacy-act-systemrecords-notices, the comments are searchable by the name of 
the submitter.

C. Regulation Identifier Number (RIN)

    The Department of Transportation assigns a regulation identifier 
number (RIN) to each regulatory action listed in the Unified Agenda of 
Federal Regulations. The Regulatory Information Service Center 
publishes the Unified Agenda in April and October of each year. You may 
use the RIN contained in the heading at the beginning of this document 
to find this action in the Unified Agenda.

    Issued in Washington, DC, under authority delegated in 49 CFR 
1.95 and 501.5.
Ann Carlson,
Acting Administrator.
[FR Doc. 2023-27665 Filed 1-4-24; 8:45 am]
BILLING CODE 4910-59-P