Sharing Interference.             impact of           sharing             testing             spectrum sharing
                                   unlicensed U-NII    feasibility.        unlicensed          interference is
                                   devices on the                          devices that        pending the
                                   transmission and                        would share the     conduct of tests
                                   reception of                            band with           with
                                   safety critical                         licensed DSRC       representative U-
                                   warnings in a                           devices has been    NII-4 devices
                                   shared spectrum                         developed. The      that operate in
                                   environment.                            testing will        the 5.9 GHz
                                                                           evaluate the        (DSRC) frequency
                                                                           feasibility of      band.Testing
                                                                           sharing spectrum    could be
                                                                           with unlicensed     completed within
                                                                           devices.            12 months of
                                                                                receipt of
                                                                                prototype
                                                                                devices.
Research Need VII-1 Consumer      Supplement the      V2V Crash           This review needs   September 2015.
 Acceptance.                       driver acceptance   Avoidance Safety    to extend the
                                   analysis            Technology Public   current
                                   completed per the   Acceptance Review.  evaluation of
                                   Driver Clinics                          driver acceptance
                                   and Safety Pilot                        to a broader
                                   Model Deployment                        public acceptance
                                   with further                            context and
                                   research that                           evaluate how
                                   includes a                              public acceptance
                                   focused                                 may impact and or
                                   assessment of                           influence the
                                   privacy in                              design,
                                   relation to V2V                         performance,
                                   technology.                             operation, and
                                                                           implementation of
                                                                           this technology.
Research Need VIII-1 V2V          [VIII-1] Assess     Independent         The objective of    March 2016.
 Location Tracking via BSM.        the availability    Evaluation of V2V   this Task Order
                                   of information      Security Design     is to perform:
                                   and technologies    and Technical       (1) an
                                   that facilitate     Analysis of the     independent and
                                   linking data in     Potential Privacy   comprehensive
                                   the BSM to          Risk of V2V         technical
                                   determine a motor   Systems.            analysis of the
                                   vehicle's path.                         V2V security
                                                                           system design
                                                                           that is currently
                                                                           proposed
                                                                           specifically for
                                                                           a V2V connected
                                                                           vehicle
                                                                           environment; and
                                                                           (2) a technical
                                                                           analysis of the
                                                                           potential privacy
                                                                           risks of the
                                                                           entire V2V system
                                                                           that includes
                                                                           security but also
                                                                           focuses on the
                                                                           operation of V2V
                                                                           communications in
                                                                           support of crash
                                                                           avoidance safety
                                                                           applications.
Research Need VIII-2 V2V          [VIII-2]
 Identification Capabilities.      Understanding and
                                   quantifying risk
                                   of linking
                                   vehicle tracking
                                   or other
                                   information in
                                   the BSM to a
                                   specific vehicle,
                                   address, or
                                   individual via
                                   available
                                   resources
                                   (including but
                                   not limited to
                                   database matching
                                   or data mining).
Research Need VIII-3 V2V          [VIII-3] Inventory
 Inventory of Privacy Controls.    and assess the
                                   privacy controls
                                   applicable to the
                                   SCMS in
                                   connection with
                                   our comprehensive
                                   privacy
                                   assessment.
Research Need VIII-4 V2V Privacy  [VIII-4] A
 Risk Assessment.                  comprehensive
                                   privacy risk
                                   analysis of all
                                   aspects of the
                                   V2V system
                                   including
                                   infrastructure
                                   equipment, on-
                                   board vehicle
                                   systems, wireless
                                   and wired
                                   communications,
                                   as well as
                                   organizational
                                   and management
                                   issues.

Research Need IX-2 Cryptographic  [IX-2] The chosen
 flexibility.                      cryptographic
                                   algorithms are
                                   estimated to be
                                   resilient against
                                   brute force
                                   attack for a few
                                   decades with some
                                   susceptibility
                                   through an
                                   unanticipated
                                   weakness. In the
                                   future new
                                   algorithms could
                                   enable better
                                   performance but
                                   may require
                                   redesign of
                                   functions or
                                   operations within
                                   the SCMS.
Research Need IX-3 Independent    [IX-3] Independent
 Security Design Assessment.       evaluation of
                                   CAMP/USDOT
                                   security design
                                   to assess
                                   alignment with
                                   Government
                                   business needs,
                                   identify minimum
                                   requirements,
                                   assess the
                                   security designs
                                   ability to
                                   support trusted
                                   messages and
                                   appropriately
                                   protect privacy,
                                   identify and
                                   remove
                                   misbehaving
                                   devices, and be
                                   flexible enough
                                   to support future
                                   upgrades.
Research Need IX-1 Misbehavior    Development of the  Crash Avoidance     The CAMP System     Initial
 Authority.                        processes,          Metrics             engineering         Misbehavior
                                   algorithms,         Partnership         project will        Detection
                                   reporting           System              investigate the     information to be
                                   requirements, and   Engineering         implementation      completed
                                   data requirements   project, Security   and device          December 2015.
                                   for both local      Credential          requirements for
                                   and global          Management Proof    local (vehicle
                                   detection           of Concept          based)
                                   functions; and      project, and        misbehavior
                                   procedures to       Communication       detection and
                                   populate and        Research Project.   global (system-
                                   distribute the                          wide) misbehavior
                                   CRL.                                    detection. The
                                                                           Communication
                                                                           Research project
                                                                           will research
                                                                           local and global
                                                                           misbehavior
                                                                           detection needs.
                                                                           The SCMS Proof of
                                                                           Concept will
                                                                           investigate
                                                                           implementation
                                                                           aspects from the
                                                                           security system
                                                                           perspective.
----------------------------------------------------------------------------------------------------------------

              Table II-6--V2V Safety Application Improvement and Performance Verification Research
                                                [NPRM IRRELEVANT]
----------------------------------------------------------------------------------------------------------------
                                                       Research projects
 Readiness report research need       Description        initiated to         Description       Completion date
                                                            address
----------------------------------------------------------------------------------------------------------------
Research Need V-4 Development of  [V-4] This          Volpe False Alert   The Volpe project   Volpe Completion
 Safety Application Test Metrics   research will       Scenarios and       will support        Date--December
 and Procedures.                   take the            Objective Test      NHTSA development   2018.
Research Need VI-2 Safety          performance         Procedures for      of false-positive  VRTC Completion
 Application Performance Measure   measures and        Crash Avoidance     warning objective   Date--April 2019.
 Rationale.                        objective test      Applications        test procedures
                                   procedures used     project and         in conjunction
                                   during the          Vehicle Research    with development
                                   research of V2V     and Test Center     of objective test
                                   applications and    project.            procedures and
                                   develop FMVSS                           performance
                                   level performance                       criteria for IMA,
                                   measures and                            LTA, FCW, and BS/
                                   safety                                  LCW applications.
                                   application                             The results of
                                   objective tests.                        this IAA will
                                                                           contribute to
                                                                           potential Federal
                                                                           Motor Vehicle
                                                                           Safety Standards
                                                                           (FMVSS) for these
                                                                           crash avoidance
                                                                           applications.
Research Need VI-3                [VI-1] Assess the   ..................  The VRTC project
 Practicability of Non-Ideal       capability and                          will incorporate
 Driving Condition Testing.        capacity of                             results and
                                   possible                                information from
                                   refinements to                          the Volpe project
                                   reduce frequency                        to develop
                                   of false positive                       Federal Motor
                                   warning while                           Vehicle Safety
                                   maintaining crash                       Standards (FMVSS)
                                   avoidance                               for these crash
                                   effectiveness.                          avoidance
                                                                           applications.
                                  [VI-2] Develop a
                                   rationale to
                                   support each
                                   performance and
                                   test metric
                                   recommended for
                                   incorporation
                                   into an FMVSS.

                                  [VI-3] Evaluate
                                   test variations
                                   for non-ideal
                                   driving
                                   conditions (e.g.,
                                   curved roads,
                                   turn signal use,
                                   weather, oblique
                                   intersections)
                                   and develop a
                                   rationale
                                   supporting the
                                   inclusion or
                                   exclusion of
                                   those test
                                   conditions.
Research Need VI-4 Fused and Non- [VI-4] Develop
 Fused V2V Safety Application      test procedures
 Test Procedures.                  that can be
                                   applied to
                                   systems relying
                                   solely on V2V
                                   information as
                                   well as ``fused''
                                   systems, those
                                   relying on both
                                   V2V and other
                                   sources of
                                   information
                                   (e.g., on-board
                                   sensors).
Research Need VI-5 Performance    [VI-5] Conduct
 and Test Metric Validation.       test validation
                                   to ensure that
                                   the performance
                                   and test metrics
                                   are objective,
                                   repeatable, and
                                   practicable.
Research Need VI-1 False          Assess the          Volpe False Alert   The Volpe project   Volpe Completion
 Positive Mitigation.              capability and      Scenarios and       will support        Date--December
                                   capacity of         Objective Test      NHTSA development   2018.
                                   possible            Procedures for      of false-positive
                                   refinements to      Crash Avoidance     warning objective
                                   reduce frequency    Applications        test procedures
                                   of false positive   project and.        in conjunction
                                   warning while                           with development
                                   maintaining crash                       of objective test
                                   avoidance                               procedures and
                                   effectiveness.                          performance
                                                                           criteria for IMA,
                                                                           LTA, FCW, and BS/
                                                                           LCW applications.
Research Need VI-6 DVI Minimum    Determine DVI's     V2V On-Road DVI     Testing DVIs for    VTTI Completion
 Performance Requirements.         impact on           Project.            Intersection        Date: November
                                   effectiveness of                        Movement Assist     2016.
                                   system and safety                       and Left Turn
                                   benefits                                Assist for
                                   applications to                         stopped vehicles.
                                   establish minimum
                                   performance for
                                   crash avoidance
                                   and objective
                                   test procedures.
----------------------------------------------------------------------------------------------------------------

D. V2V International and Harmonization Efforts

    Section V.F of NHTSA's Readiness Report detailed key similarities
and some differences between U.S., European, and Asian V2X
implementation approaches. There are several organizations in Europe
and Asia conducting activities related to V2V and V2I communications
and the U.S. DOT has established ongoing coordination activities with
these regions and their representing organizations. For Europe, these
organizations include DG CONNECT and the CAR 2 CAR Communications
Consortium (C2C-CC). DG CONNECT is the EU directorate responsible for
conducting research and pilot projects related to connected vehicles
and C2C-CC has been working closely with CAMP as part of the EU-US V2X
Harmonization Program.
    A number of commenters to the ANPRM/Readiness Report addressed the
issue of global harmonization. Most commenters addressing the issue
encouraged the agency to pursue global harmonization between the U.S.,
EU, and Asia-Pacific regions as a way to reduce costs,\38\ and also to
facilitate cross-border traffic, as between NAFTA countries.\39\ A
number of commenters discussed existing or under-development technical
standards by bodies such as ETSI, ISO, and the EU-US Task Force on ITS,
and called on NHTSA to support them,\40\ and some commenters suggested
that NHTSA work to develop a Global Technical Regulation (GTR) and
facilitate harmonization through that approach.\41\
---------------------------------------------------------------------------

    \38\ Mercedes at 7; Alliance at 50; Automotive Safety Council at
3; Harley-Davidson at 2; Volvo Group at 3;
    \39\ Alliance at 50; Global at 19-20; Pennsylvania DOT at 7; TRW
Automotive at 7.
    \40\ Mercedes at 7; Systems Research Associates, Inc., at 10;
SAE International at 5; Delphi at 10; Continental Automotive Systems
at 3.
    \41\ Automotive Safety Council at 3; Volvo Group at 4.
---------------------------------------------------------------------------

    With regard to what specifically should be harmonized, commenters
mentioned hardware,\42\ software,\43\ DVI,\44\ and BSM,\45\ although
Cohda Automotive argued that global harmonization efforts have
effectively already resulted in a single hardware platform being
possible, and that different software could run in each region.\46\
Some industry commenters cautioned, however, that NHTSA should not let
harmonization objectives impede safety.\47\ Mercedes expressed concern
that harmonization should not just be global, but also consider the
risk of a patchwork of differing State regulations for advanced
technologies, and asked that NHTSA work with State DOTs to avoid
this.\48\
---------------------------------------------------------------------------

    \42\ Mercedes at 7.
    \43\ Mercedes at 7.
    \44\ Automotive Safety Council at 3; TRW Automotive at 7.
    \45\ TRW Automotive at 7.
    \46\ Cohda Wireless at 9.
    \47\ Alliance at 50, Global at 19-20.
    \48\ Mercedes at 8.
---------------------------------------------------------------------------

    NHTSA recognizes the value of implementing V2V in a globally-
harmonized way. Consistency could reduce costs, complexity, and
contribute to a successful, long-term sustainable deployment. As
discussed in the V2V Readiness Report, significant V2V research and
development activities have been completed and continue in both Europe
and Asia. Real-world deployments have been announced in both regions
focusing on V2I systems to

aid drivers and to attempt improvements in traffic flow.
    Collaboration between organizations and governmental bodies in the
U.S. and Europe has led to extensive harmonization of the criteria for
hardware, message sets, security, and other aspects needed to support
V2V between the two regions. It will be possible to use common radios
and antennas in both regions. Harmonization could potentially be
enhanced by this proposal by prompting solidification of the work
focusing on security and message performance requirements for common
applications. The connected vehicle applications being developed in
Europe place a much stronger priority on mobility and sustainability
compared to U.S. focus on safety applications.
    Japan, Korea and Australia are the Asia-Pacific countries most
involved in pursuing DSRC-based V2X communications. In Japan, MLIT's
current V2X approach centers on the adaptation of their electronic
tolling system operating at 5.8 GHz. Additionally, some Japanese OEMs
(mainly Toyota) are actively supporting the deployment of V2X using 760
MHz communications. Development of message sets in Japan is not yet
complete but appears to be moving in a similar direction as the message
sets harmonized between Europe and the U.S. Korea currently uses the
5.835-5.855 GHz band for Electronic Toll Collection and DSRC
experimentation. Korea has performed field tests for V2V communication
in this band. Industry sources indicate that Korea may shift DSRC for
ITS to 5.9 GHz to be more aligned internationally.
    In Australia, Austroads is the association of Australian and New
Zealand road transport and traffic authorities. This organization is
currently investigating potential interference issues, and working with
affected license holders to evaluate the feasibility of use of the 5.9
GHZ spectrum for V2X in Australia. Another agency, Transport
Certification Australia, is leading the design for security
requirements, supporting field deployments, and working with the
Australian Communications and Media Authority (ACMA) on identifying
requirements for spectrum usage. Because the Australian vehicle market
is predominantly comprised of imports from the U.S., Europe, and Asia,
these Australian agencies have joined in the international
harmonization efforts to ensure that the vehicle brought into the
country are interoperable with each other and with the new cooperative
infrastructure equipment and applications emerging on the market.
    Canada has reserved spectrum at 5.9 GHz for V2X and is watching
developments in the U.S. closely.
    Harmonization and joint standardization is performed under an
Implementing Arrangement for Cooperative Activities. This memorandum
between the U.S. DOT and the European Commission established a
collaborative relationship in 2009 and it was renewed in December
2014.\49\
---------------------------------------------------------------------------

    \49\ ``Continuation of the Implementing Arrangement between the
U.S. Department of Transportation and the European Commission''
http://www.its.dot.gov/press/2015/euro_commission.htm#sthash.URMW4OOH.dpuf (last accessed Dec 8,
2016).
---------------------------------------------------------------------------

    The harmonization and collaboration on standards is governed by a
Harmonization Work Plan that has generated a set of smaller, flexible
task groups to focus on specific subjects. The completed and ongoing
task groups and their status are the following:
     Harmonization Task Group (HTG) 1 on Security Standards and
HTG3 on Communications Standards performed their analysis in 2011 with
completion of results in 2012. HTG1 (which included experts from ISO,
CEN, ETSI, IEEE) worked in coordination with HTG3 to identify the
subset of available standards to provide assurance of interoperable
security measures in a cooperative, interoperable environment. Because
HTG 1 and HTG 3 issues were sufficiently interrelated and the HTGs had
a significant overlap in membership, work on these topics was conducted
jointly. The analysis documented how implementations of the protocol
stack might not be interoperable because the specification of technical
features from various Standards Development Organizations (SDOs) was
different or incomplete. These differences presented interoperability
challenges. HTG1 and 3 results provide guidance to the SDOs for actions
to be taken that raise the assurance of security interoperability of
deployed equipment. Vehicle connectivity through harmonization of
standards and architecture will reduce costs to industry and consumers,
in that hardware and/or software development costs will be spread over
a larger user base, resulting in reduced unit costs. Differences
between vehicles manufactured for different markets will also be
minimized, allowing private-sector markets to have a greater set of
global opportunities. A final outcome of the HTG1 and HTG3 work was
recognition of the need to harmonize security policies and standards.
To meet this need, a third HTG (HTG6) was established to explore and
find consensus on management policies and security approaches for
cooperative ITS.
     HTG2 on Harmonization of US BSM and EU CAM: The goal of
HTG2 was to harmonize the vehicle-to-vehicle safety messages that had
been developed within the EU and separately within the U.S. The group
was able to harmonize on the hardware issues. However, differing U.S.
and EU software approaches and institutional issues constrained the
extent to which a single, cross-region safety message set could be
developed. While a single message set did not result, the HTG was able
to evolve the two messages in a manner such that simple software
translation between the two message sets is sufficient to allow cross-
compatibility. It was a significant step to be able to have the two
message sets become substantially closer in nature. These advancements
will facilitate deployment across multiple regions using similar or
identical hardware and software modules.
     HTG4/5 on Infrastructure Message Standards: HTG 4/5 is
currently in-progress. Its scope is to address the need for
standardized Vehicle-to-Infrastructure message sets and interfaces,
including:
    [cir] Signalized intersections applications such as Signal Phase
and Timing, Signal Request, Signal Status,
    [cir] In-vehicle data message sets.

    At this point, there is general agreement on the data concepts in
these message sets, but there remain differences in how the data is
conveyed between the infrastructure and the vehicles. These differences
are due to project and communications restrictions. For example, the
U.S. is planning for additional message sets for enhanced
functionality; whereas the European approach may limit the initial
applications and simply add data elements to the messages over time.
ISO Technical Specification 19091, a standard covering to V2I and I2V
communications for signalized intersections, is currently under
development and is incorporating both harmonized content and
recognizing region-specific content--a practical compromise resulting
from existing differences in signal standards. Overall, 19091 allows
for substantial hardware congruity while acknowledging that fully
identical message standards are not viable at this time.
     HTG6 on Harmonized Development of a Cooperative-ITS
Security Policy Framework: HTG6 assessed security policy needs across
international,

regional, and local levels. Analysis was performed to determine optimal
candidate guidelines for policy areas. HTG6's intent was to identify
where harmonization is desirable by exploring the advantages and
limitations of global versus local security policy alternatives,
including economic benefits. Implementation of harmonized policies
engenders and sustains public trust in the C-ITS system and
applications, particularly with a highly mobile environment that
expects C-ITS services to remain available as they cross borders as
well as over time. The task group is identifying the largest set of
common approaches and interfaces for harmonization, recognizing that
there will be multiple instantiations of security entities within and
adjacent to geographic/jurisdictional borders. Although minimizing the
number significantly decreases cost and complexity, decisions to own
and operate security occur for diverse reasons, specifically because of
differing jurisdictional requirements for security levels, privacy,
cryptographic choices, or trust model choices. The group's analysis
recognizes the benefits for commonality and identifies those policies
and harmonized interfaces that support regional implementations that
might diverge. At the time of developing this proposal, most of the
reports from this activity are posted.\50\
---------------------------------------------------------------------------

    \50\ ``Harmonized security policies for cooperative Intelligent
Transport Systems create international benefits'' October 16, 2016.
https://ec.europa.eu/digital-single-market/news/harmonized-security-policies-cooperative-intelligent-transport-systems-create-international (last accessed: Dec 8, 2016).
---------------------------------------------------------------------------

    The SCMS development activity has incorporated key outcomes of this
activity, some of which include:
     Implementation of harmonized policies engenders and
sustains public trust in the C-ITS system and applications,
particularly within a highly mobile environment that expects C-ITS
services to remain available as networks evolve over time and as
services cross borders.
     To support cross-border/cross-jurisdictional operations of
C-ITS applications, individual security systems (known as C-ITS
Credential Management Systems or CCMS) require a defined range of
harmonized processes as well as specific, secure data flows to support
digital auditing and system transparency.
     Planning for inter-CCMS or intra-CCMS communications will
require decisions when developing near-term operational systems but
those decisions may have longer-term impacts on crypto-agility, system
flexibility, and evolution of systems that must be considered from the
start.
     Critical near-term steps for policy and decision makers to
perform include:
    [cir] Minimize the number of CCMS: Policy makers must determine the
number of CCMS that will be operational within a local, regional, or
national jurisdiction. Increasing the number of CCMS, in particular the
root authorities, significantly increases complexity and cost.
    [cir] Assess risk and set appropriate parameters for risk and
privacy: No system will ever be without risk. Policy and decision
makers must set acceptable levels of internal and external risk, as
well as levels of privacy protection. Further, systems managers must
assess these levels continuously throughout the lifecycle both of the
security solution as well as end-entity (user) devices and
applications. Risk and privacy levels come with trade-offs that will
need to be assessed by policy makers.
    [cir] Choose appropriate trust models: After system managers assess
and categorize risk, they can identify policy and technical controls to
mitigate risk. Collectively, these controls support the implementation
of trust models that range from no trust among security entities to
full trust that allows users (``trusted actors'' that are accepted into
the C-ITS security environment) to receive security services even after
leaving their ``native'' system in which they are enrolled. Decisions
are also required to establish criteria that define who are trusted
actors and policies and procedures for certification, enrollment,
removal in the event of misbehavior, and reinstatement.
    [cir] Establish Governance: These decisions include the
identification and convening of key stakeholders who will require
representation in ongoing decision-making. Once convened, this group
will establish processes for decision-making, define criteria for new
entrants into the governance process, assign roles and
responsibilities, establish authority to provide governance and
enforcement, and determine enforcement procedures.
    [cir] Implement harmonized processes: The HTG6 team identified the
priority areas for harmonization in report HTG6-3 and identified the
interfaces and data flows where the policies would be applied in HTG6-
4. Policy makers will need to examine them to determine which ones are
appropriate both to support their choice in trust models and throughout
the CCMS lifecycle.
    HTG group members comprise a small group of international experts
who worked together intensively with co-leadership. Members are
provided by the EC DG-CONNECT and U.S. DOT, and typically chosen from
among the editors of many of the current cooperative ITS standards in
the different SDOs providing direct linkages into those SDO activities,
as well as representatives of the EU and U.S. DOT and the Vehicle
Infrastructure Integration Consortium (VIIC), and expert
representatives from roadway and infrastructure agencies, system
integrators, and policy analysts. HTG6 expanded the membership beyond
the EC and U.S. DOT to include Transport Certification Australia (TCA)
plus observers from Canada and Japan.
    As the U.S. is taking the lead in potential V2V deployment, whereas
Asia and Europe are focusing primarily on V2I implementation, the
agency expects that a finalized implementation driven by this proposal
will set precedent and potentially adjust standards for V2V
implementation globally.

E. V2V ANPRM

    To begin the rulemaking process, NHTSA issued an ANPRM on August
20, 2014.\51\ Accompanying the ANPRM, NHTSA also published a research
report discussing the status of V2V technology and its readiness for
application (``V2V Readiness Report'').\52\ NHTSA's goal in releasing
these two documents in 2014 was to not only announce the agency's
intent to move forward with the rulemaking process, but also to
comprehensively collect all of the available information on V2V and
present this information to the public to collect comments that would
further help the agency refine its approach with regard to V2V.
---------------------------------------------------------------------------

    \51\ 79 FR 49270.
    \52\ Docket No. NHTSA-2014-0022-0001.
---------------------------------------------------------------------------

1. Summary of the ANPRM
    In the ANPRM and the accompanying V2V Readiness Report, we
emphasized the capability of V2V to be an enabler for many advanced
vehicle safety applications as well as an additional data stream for
future automated vehicles.\53\ We also stated our belief that a mandate
to include DSRC devices in all vehicles would facilitate a market-
driven approach to safety, and possibly other, application
deployment.\54\
---------------------------------------------------------------------------

    \53\ 79 FR 49270.
    \54\ Id.
---------------------------------------------------------------------------

    Current advanced vehicle safety applications (e.g., forward
collision warning, automated braking, lane keeping, etc.) use on-board
sensors (e.g., cameras, radars, etc.) to perceive a vehicle's
surroundings. Because each

type of sensor has advantages and disadvantages under different
conditions, manufacturers seeking to incorporate advanced functions in
their vehicles are increasingly relying on sensor fusion (i.e., merging
information from different sources) to ensure reliable information is
available to the vehicle when it makes crash-imminent decisions. When
compared to on-board sensors, V2V is a complementary, and unique,
source of information that can significantly enhance the reliability of
information available to vehicles. Instead of relying on each vehicle
to sense its surroundings on its own, V2V enables surrounding vehicles
to help each other by communicating safety information to each other.
In addition, V2V enables new advanced vehicle safety functionality
because it enables vehicles to receive information beyond the range of
``traditional'' sensing technology.
    One important example that we mentioned in the ANPRM is
intersection crashes.\55\ Because of V2V's ability to provide vehicles
with information beyond a vehicle's range of perception, V2V is the
only source of information that supports applications like Intersection
Movement Assist (IMA) and Left Turn Assist (LTA). These applications
have the unique ability to address intersection crashes, which are
among the most deadly crashes that drivers currently face in the
U.S.\56\
---------------------------------------------------------------------------

    \55\ Id.
    \56\ Id.
---------------------------------------------------------------------------

    However, in spite of the benefits of the technology, we explained
in the ANPRM that we did not expect that V2V technology would be
adopted in the vehicle fleet absent regulatory action by the
agency.\57\ Due to the cooperative nature of V2V, we stated that early
adopters of the technology would not realize immediate safety benefits
until a sufficient number of vehicles in their geographical area have
the technology.\58\ In other words, early adopters incurring the costs
to equip their vehicle to transmit BSM information about their vehicle
would not realize the benefit of the V2V information environment unless
other vehicles in their surroundings are also transmitting and
receiving BSM information.
---------------------------------------------------------------------------

    \57\ Id.
    \58\ Id.
---------------------------------------------------------------------------

    In the V2V Readiness Report,\59\ we observed that, based on the
data collected from the Safety Pilot Model Deployment Project, V2V
systems work in real world testing. V2V-equipped vehicles successfully
exchanged BSM information with each other and issued warnings to their
drivers.\60\
---------------------------------------------------------------------------

    \59\ V2V Readiness Report. Docket No. NHTSA-2014-0022-0001. Page
xv.
    \60\ Id. at xv.
---------------------------------------------------------------------------

    We further discussed and summarized our preliminary information
regarding many of the technical aspects of a potential rule including:
The types of safety problems that could be addressed by V2V,\61\ the
potential technological solutions to those problems (V2V-based or
otherwise),\62\ the potential hardware/software component that could be
used in DSRC devices,\63\ the applications that could be enabled by
V2V,\64\ and preliminary design concepts for a security system for the
V2V environment.\65\
---------------------------------------------------------------------------

    \61\ Id. at 15.
    \62\ Id. at 25.
    \63\ Id. at 65.
    \64\ Id. at 119.
    \65\ Id. at 158.
---------------------------------------------------------------------------

    The report also explored various important policy issues including:
the agency's legal authority over the various aspects of the V2V
environment (e.g., the vehicle components, aftermarket devices,
etc.),\66\ issues that may be outside the scope of NHTSA's
activities,\67\ privacy and public acceptance concerns over V2V
technology,\68\ and potential legal liability implications.\69\ In
addition, we began the process of analyzing the costs of a potential
rule to require V2V capability in vehicles based on different
technology assumptions and different scenarios for adoption.\70\ While
we acknowledged that there are a variety of potential benefits of V2V,
we conducted a preliminary estimate of the benefits attributable to two
V2V-specific safety applications.\71\ Finally, throughout the V2V
Readiness Report, we also identified various research and policy gaps
in each of the substantive areas that we discussed.\72\
---------------------------------------------------------------------------

    \66\ Id. at 33.
    \67\ Id. at xvi.
    \68\ Id. at 133.
    \69\ Id. at 208.
    \70\ Id. at 216.
    \71\ Id. at 259.
    \72\ See e.g., id. at xix.
---------------------------------------------------------------------------

    In the context of the V2V Readiness Report, the ANPRM asked 57
questions to help solicit comments from the public more
effectively.\73\ While the questions we asked in the ANPRM covered a
variety of subjects, many of our questions covered issues relating to
estimating costs and benefits.\74\ For example, we asked the public
about potential ways to obtain real-world test data concerning the
effectiveness of V2V safety applications and whether we have identified
the relevant potential crash scenarios for calculating benefits.\75\ On
the same subject, we asked if preferring certain technologies over
others in the situation of a network good \76\ such as V2V would lead
to any detrimental impact.\77\
---------------------------------------------------------------------------

    \73\ 79 FR 49270, 49271.
    \74\ Id. See also id. at 49273-24.
    \75\ Id. at 49271.
    \76\ A network good's value to each user increases when the
number of users of that good increase (e.g., telephone). In other
words, increasing the number of users creates a positive
externality.
    \77\ Id.
---------------------------------------------------------------------------

    The ANPRM questions also covered policy issues such as legal
interpretation of NHTSA's authorities under the Motor Vehicle Safety
Act,\78\ and how commenters view the public's potential acceptance/non-
acceptance of V2V technology.\79\ The ANPRM also posed technical
questions such as, how can the agency mandate V2V can help ensure
interoperability, whether the Safety Pilot Model Deployment
sufficiently demonstrated interoperability, and whether standards under
development by organizations such as IEEE and SAE could help ensure
interoperability.\80\
---------------------------------------------------------------------------

    \78\ Id.
    \79\ Id. at 49273.
    \80\ Id. at 49272.
---------------------------------------------------------------------------

    We raised important questions regarding the potential sharing of
the DSRC spectrum allocation by soliciting comments on potential
sharing and, if so, ideas on how to share the spectrum safely.\81\ In
addition, we requested comment on the usefulness of our concepts for a
potential security design (i.e., PKI)--including specific elements like
the certificate revocation list (CRL), whether the system would create
new ``threat vectors,'' sufficiently protect privacy, how DSRC devices
could be updated, and potential cybersecurity threats.\82\
---------------------------------------------------------------------------

    \81\ Id.
    \82\ Id. at 49273.
---------------------------------------------------------------------------

2. Comments to the ANPRM
    In response to the ANPRM, the V2V Readiness Report, and our
questions, we received more than 900 comments.\83\ The agency received
responses to the ANPRM from a diverse set of commenters representing a
wider range of perspectives than with other agency safety rules. They
range from more traditional commenters to NHTSA safety rulemakings
(e.g., automobile manufacturers/suppliers, trade associations,
standards development organizations, safety advocacy groups, individual
citizens, etc.) to newer participants in such rulemakings such as
technology/communications companies, other state/federal agencies, and
privacy groups. The comments also

covered a wide variety of topics ranging from the technical details of
V2V technology to the policy implications of any potential rule. While
this document discusses the relevant comments in much greater detail
when discussing each aspect of the proposal (in the sections that
follow), the paragraphs here contain a sampling of the types of
commenters and the major issues they raised.
---------------------------------------------------------------------------

    \83\ See Docket No. NHTSA-2014-0022.
---------------------------------------------------------------------------

    While expressing general support, the automotive manufacturers
stated their belief that the Federal government needs to assume a large
role in establishing key elements of the V2V environment (e.g.,
establishing common operating criteria for V2V devices, establishing a
security credentials system, preserving the 5.9 GHz spectrum for V2V
safety, and mandating devices in new vehicles).\84\ The automotive
manufacturer commenters discussed their legal concerns (including
concerns over practicability of an FMVSS if certain aspects of the V2V
environment are missing and potential legal liability for
manufacturers).\85\ While generally agreeing with our assessment
regarding the readiness of some of the industry technical standards to
ensure that V2V communications work, the automotive manufacturer
commenters also emphasized the importance of privacy and public
acceptance to the success of the technology.\86\ In spite of some of
these open policy and technical questions, many automotive manufacturer
commenters also agreed that a regulation or requirement defining key
items needed for interoperability is necessary to realize the full
potential benefits of V2V.\87\
---------------------------------------------------------------------------

    \84\ See e.g., Comments from the Alliance of Automobile
Manufacturers, Docket No. NHTSA-2014-0022-0603.
    \85\ See id.
    \86\ See id.
    \87\ See e.g., Comments from Ford Motor Company, Docket No.
NHTSA-2014-0022-0953.
---------------------------------------------------------------------------

    Automotive suppliers generally expressed support for the technology
as well. They further generally opined that the technology and
standards for the technology are mature enough for initial deployment.
For example, DENSO \88\ stated that DSRC is a suitable technology for
implementing V2V safety applications and that the current BSM is
adequate to support those purposes. Continental further commented that
V2V demonstrations thus far show that the system works and is
interoperable.\89\ Raising different points, Delphi commented that the
coverage of a potential V2V rule should include more than just the
vehicles contemplated in the ANPRM and that the technology should be
developed in conjunction with the vehicle-resident systems.\90\
---------------------------------------------------------------------------

    \88\ See Docket No. NHTSA-2014-0022-0655.
    \89\ See Docket No. NHTSA-2014-0022-0414.
    \90\ See Docket No. NHTSA-2014-0022-0266.
---------------------------------------------------------------------------

    Safety advocacy groups also expressed support, but emphasized the
importance of ensuring interference-free spectrum for V2V. For example,
the American Motorcyclist Association stressed the need for
interference-free spectrum to ensure the safety applications will
function. V2V, in their view, has the unique capability to address
crashes that represent a significant portion of motorcycle crashes
(e.g., left turn across path crashes).\91\ They also emphasized the
importance of a uniform human-machine interface for safety applications
(regardless of whether the applications use V2V or vehicle-resident
based information).\92\ Other safety advocacy groups (e.g., the
Automotive Safety Council) covered a large variety of topics (e.g.,
emphasizing the importance of interoperability, the ability of V2V to
work in conjunction with vehicle-resident systems, and expressing
concern that the security system described in the report would not
sufficiently protect against all forms of ``abuse'' of the V2V
environment).\93\
---------------------------------------------------------------------------

    \91\ See Docket No. NHTSA-2014-0022-0646.
    \92\ Consumers Union discussed the HMI and how warnings need to
be effectively communicated to the driver. See Docket No. NHTSA-
2014-0022-0533.
    \93\ See e.g., Docket No. NHTSA-2014-0022-0511.
---------------------------------------------------------------------------

    Two standards development organizations also submitted comments.
The two organizations (SAE and IEEE) were involved in developing
various standards incorporated in this proposed rule. Both generally
expressed support for the agency's proposal and stated that--in spite
of on-going research--the standards are mature enough to support
deployment of DSRC devices and ensure that they are interoperable.\94\
Where the standards organizations differed was their opinion concerning
spectrum availability. SAE reiterated its concern that ``interference-
free spectrum'' is critical for the V2V environment.\95\ While IEEE
suggested that spectrum sharing is feasible, they opined that DSRC
deployment should not wait for further research on spectrum
sharing.\96\ Instead ``acceptable sharing parameters'' may be
determined at a later date after DSRC deployment and further
research.\97\
---------------------------------------------------------------------------

    \94\ See e.g., Docket No. NHTSA-2014-0022-0597.
    \95\ See id.
    \96\ See Docket No. NHTSA-2014-0022-0693.
    \97\ Id.
---------------------------------------------------------------------------

    While expressing general support for the technology and NHTSA's
efforts in this area, technology/communications device manufacturers
expressed two general concerns. Through their trade associations,\98\
such manufacturers raised questions about NHTSA's authority to regulate
software and mobile devices.\99\ In addition, individual companies
(e.g., Qualcomm \100\) and other associations (e.g., the Wi-Fi Alliance
\101\) expressed their opinion regarding the viability of spectrum
sharing with unlicensed Wi-Fi devices and the ability of V2V to
flourish alongside other technologies that will benefit automotive and
highway safety. Finally, the Information Technology Industry Council
stated its belief that NHTSA needs to ensure that connected vehicle
technologies are allowed to develop using different technological
solutions (e.g., other communications mediums beyond DSRC).\102\
---------------------------------------------------------------------------

    \98\ CTIA--The Wireless Association and the Consumer Electronics
Association.
    \99\ See e.g., Docket No. NHTSA-2014-0022-0483.
    \100\ See Docket No. NHTSA-2014-0022-0665.
    \101\ See Docket No. NHTSA-2014-0022-0644.
    \102\ See Docket No. NHTSA-2014-0022-0403.
---------------------------------------------------------------------------

    Other government agencies also submitted comments. The NTSB
commented that both V2V and vehicle-resident crash avoidance
technologies are important and they are complementary--especially when
one (vehicle-resident) fills the gap during the deployment of the other
(V2V).\103\ State agencies also commented.\104\ AASHTO also mentioned
that interference-free spectrum is critical and commented that
supporting future upgrades to the system through software rather than
hardware changes would be important for state agencies.\105\
---------------------------------------------------------------------------

    \103\ See Docket No. NHTSA-2014-0022-0267.
    \104\ State DOTs from also stress the need to have uniform HMI--
serving a purpose similar to the MUTCD for traffic signs and
signals. They also commented that other vehicle types that could
benefit from V2V (e.g., vehicles with GVWR greater than 10,000) and
mentioned the potential of other V2X applications (e.g., vehicle to
rail, agricultural equipment, horse-drawn vehicles). Further they
opine that mandate is needed to deploy quickly. See e.g., Comment
from PennDOT, Docket No. NHTSA-2014-0022-0371; TxDOT, Docket No.
NHTSA-2014-0022-0218; Wisconsin DOT, Docket No. NHTSA-2014-0022-
0507.
    \105\ See Docket No. NHTSA-2014-0022-0420.
---------------------------------------------------------------------------

    A significant number of commenters also raised privacy concerns
with this rulemaking. In addition to a large number of individual
commenters, organizations such as EPIC stated that, since a potential
rule would create significant privacy risks, they recommend that the
government take various actions to protect the information (e.g.,
establish when PII can be collected, when/where information can be
stored, additional encryption

methods, and require adherence to Consumer Privacy Bill of
Rights).\106\ In addition, Professor Dorothy Glancy expressed concern
that NHTSA plans to conduct its privacy analysis after the ANPRM stage
of the rulemaking process and is concerned that not all potential data
collection is accurately portrayed in the ANPRM.\107\ On the other
hand, while the FTC agreed that privacy concerns could exist in the V2V
environment related to (1) obtaining the vehicle location information
and (2) pricing insurance premiums over the driving habits, it believes
NHTSA has taken these concerns into account.\108\
---------------------------------------------------------------------------

    \106\ See Docket No. NHTSA-2014-0022-0689.
    \107\ See Docket No. NHTSA-2014-0022-0331.
    \108\ See Docket No. NHTSA-2014-0022-0502.
---------------------------------------------------------------------------

    Finally, many individual citizen commenters (in addition to the
topics covered above) discussed their perception that this rulemaking
proposes to mandate a technology that poses a potential health concern.
The EMR Policy Institute \109\ expressed similar concerns stating that
NHTSA should postpone this rulemaking until the FCC changes their
guidelines regarding human radiation exposure to wireless
communications.
---------------------------------------------------------------------------

    \109\ See Docket No. NHTSA-2014-0022-0682.
---------------------------------------------------------------------------

F. SCMS RFI

    Approximately 30 days after issuing the agency's Advance Notice of
Proposed Rulemaking (ANPRM) \110\ and V2V Readiness Report, NHTSA
released a Request for Information (RFI) \111\ regarding a Security
Credential Management System (SCMS) that could support a national
deployment of a V2V communication system. NHTSA was interested in
hearing from entities interested in establishing components of an SCMS
or the SCMS, itself. The RFI was issued separately from the ANPRM and
V2V Readiness Report to give potential respondents additional time to
review the more-detailed V2V Readiness Report content on the SCMS,
allowing time for respondents to formulate informed responses to the
Agency's questions about how an SCMS should be designed and whether
they would be interested in developing or operating components or the
SCMS, as a whole. As discussed in the ANPRM and V2V Readiness Report,
we explained that NHTSA would not require the SCMS by regulation and
did not expect to establish, fund or operate the SCMS.
---------------------------------------------------------------------------

    \110\ 79 FR 49270 (Aug. 20, 2014).
    \111\ 79 FR 61927 (Oct. 15, 2014).
---------------------------------------------------------------------------

    Questions in the RFI covered topics such as potential governance
structures for the SCMS, requests for estimates of necessary initial
capital investment, how respondents believed the SCMS (or the
components that they were interested in operating) could generate
revenue and be financially sustainable (in order to ensure its
uninterrupted operation), what respondents thought of the current SCMS
design and, finally, the respondent's interest in standing up and
operating some or all of the components of the national V2V SCMS.
    NHTSA received 21 responses by the December 15, 2014 response
closing date, and approximately 11 respondents indicated an interest in
running some or all components of the SCMS. The remaining responses
commented more generally on issues of potential governance and
liability with two common themes: (1) That the Federal Government
should take the lead in standing up and operating the SCMS; and (2)
that the Federal Government should indemnify companies participating in
the SCMS from liability.
    The RFI respondents included vehicle manufacturers, software
component developers and suppliers, cryptography experts, certificate
management entities, satellite and cellular service providers and
academia. Because the process of deploying cooperative V2V technology
and supporting establishment of an SCMS both are unprecedented
activities, the agency believed it was appropriate to meet with the
subset of eleven respondents who expressed interest in operating
aspects of the SCMS or the SCMS as a whole. These meetings ensured that
the agency and the individual respondents shared a mutual understanding
of each respondent's comments, their potential role in an SCMS, and the
agency's views on the ways in which an SCMS could be established and
deployed.
    Meeting discussions covered a wide range of topics--including
details of cryptography intricacies, certificate distribution
methodologies, root storage and protection, to potential overall SCMS
management. NHTSA found these meetings to be very beneficial in terms
of introducing the agency to some new potential stakeholders and
service providers different than the vehicle OEMs and suppliers with
whom NHTSA typically. The diversity of RFI respondents exemplified the
multi-stakeholder and cross-cutting nature of the V2V ecosystem.
    Additional details on the SCMS RFI responses can be found in
Section V.B.4.

III. Proposal To Regulate V2V Communications

A. V2V Communications Proposal Overview

    The agency believes that it will not be possible to begin to
address the 3.4 million crashes identified in Section II.A, especially
the intersection crashes and left-turning crashes, given today's
vehicle-resident technology offerings. As described earlier, the
limitations of current sensor-based safety systems, in terms of
direction and distance, likely will not be able to address intersection
and left-turning crashes, among other potential crash scenarios, as
effectively as V2V communications could.
    The agency's proposal to regulate V2V technology is broken into
distinct functional components, some of which have alternatives that
could potentially be employed ``in-conjunction-with'' or ``in-place-
of'' the agency's proposal. The distinct functional components are: The
actual communications technology itself (Section III.E), proposed
messaging format and content requirements (Section III.E.2),
authenticating V2V messages (Section III.E.3), V2V device misbehavior
detection and reporting (Section III.E.4), malfunction indication
requirements (Section III.E.5), software and certificate updating
requirements (Section III.E.6), and proposed cybersecurity related
requirements (Section III.E.7).

B. Proposed V2V Mandate for New Light Vehicles, and Performance
Requirements for Aftermarket for Existing Vehicles

    NHTSA's proposal would require that new light vehicles include
vehicle-to-vehicle communication technology able to transmit
standardized BSMs over DSRC as described in Section III.E below,
beginning two years after issuance of a final rule and phasing in over
the following three years at rates of 50 percent, 75 percent, and 100
percent, respectively. ``Light vehicles,'' in the context of this
rulemaking, refers to passenger cars, multipurpose passenger vehicles,
trucks, and buses with a gross vehicle weight rating of 10,000 pounds
(4,536 kilograms) or less.\112\ The agency

believes that this amount of lead time and phase-in is needed based on
the potential for device supply constraints to generate production-
level quantities of devices required by automotive OEMs to meet the
standard \113\ and to allow flexibility for vehicle refresh and re-
design cycles. The proposal also allows vehicles to comply using non-
DSRC technologies that meet certain performance and interoperability
standards.
---------------------------------------------------------------------------

    \112\ ``Passenger cars,'' ``multipurpose passenger vehicles,''
``trucks,'' and ``buses'' are defined in 49 CFR 571.3. Some
commenters suggested that the agency's proposal also cover vehicles
like motorcycles and horse-drawn buggies (Wisconsin DOT), or heavy
vehicles (Bendix, among others). Both motorcycles and HVs were
included in the Safety Pilot Model Deployment, but in very small
numbers, and the agency believes that more research is needed than
what is available at the time of this NPRM before we are ready to
propose requirements for those vehicles. The agency will be making a
decision on how to proceed with V2V capability for HVs at a later
date. For buggies, these would not be considered motor vehicles, but
we are optimistic that V2X capability may eventually be available
for them.
    \113\ Impact of Light Vehicle Rule on Consumer/Aftermarket
Adoption--Dedicated Short Range Communications Market Study,
Intelligent Transportation Society of America, FHWA-JPO-17-487,
available at http://ntl.bts.gov/lib/60000/60500/60535/FHWA-JPO-17-487_Final_.pdf (last accessed Dec 12, 2016).
---------------------------------------------------------------------------

    In addition to requiring new light vehicles to be able to transmit
and receive BSMs over DSRC, the proposal would also require that
similarly-capable aftermarket devices achieve the same DSRC
performance.
    Besides being the first FMVSS to involve vehicles relying on
information transmitted by other vehicles, this FMVSS would also be the
first to incorporate elements of secure wireless communication
protection directly into the performance requirements.\114\ New motor
vehicles are increasingly computerized, and given the importance of
ensuring the availability and integrity of safety-critical systems, we
considered which requirements could best be incorporated into an FMVSS
and which should be part of the V2V security system instead. V2V
security requirements are discussed in Section III.E.3 and Section
III.E.7, along with a discussion of privacy and security in Section IV.
---------------------------------------------------------------------------

    \114\ To be clear, the related performance requirements for V2V
communication security will incorporate protections to ensure a
secure vehicle communication that are distinct from other types of
communications with the vehicle for other data transfers and
interconnectivity. The performance requirements for V2V security
communications do not and are not intended to provide comprehensive
protection for other vehicle wireless communications or internal
vehicle connectivity for operational functionality. That
responsibility continues to belong to manufacturers.
---------------------------------------------------------------------------

    The agency has put forth this proposed rule on the basis that a
fully-implemented V2V system, as currently envisioned, is a compilation
of many elements that provide a data-rich technology platform that
ensures secure and interoperable communications enabling safety
warnings and advisories for drivers. As described in the V2V Readiness
Report, V2V devices send out BSMs to alert other vehicles to their
presence, and receive BSMs from other vehicles in order to determine
whether to warn their drivers of an imminent crash situation. BSMs must
be accompanied by message authentication capabilities so that the
receiving V2V communication will allow suppliers and vehicle
manufacturers to innovate and spur the market for applications that
will provide consumers increased safety.
    The agency believes that a mandate for all light vehicles is
necessary to achieve the safety goals of this proposal. The two vital
pieces in order to achieve these crash avoidance benefits are (1)
ensuring interoperable V2V communications, and (2) achieving a critical
mass of communicating vehicles in the American fleet. NHTSA believes
that this proposal is the only way to achieve these two pieces because
of the lagging adoption of advanced safety technologies in the
marketplace. As evidenced by the slow voluntary deployment of vehicle
sensor-based advanced driving assistance systems, the agency believes
that it will be even more difficult to achieve a critical V2V
implementation level without a mandate due to the cooperative nature of
the V2V system. If it cannot reach a critical deployment level within a
certain timeframe, the safety benefits of V2V would drop dramatically,
and manufacturers would have much less incentive to develop the safety
applications (despite their relatively low costs) because they would
not have a reason to make the initial investment to install the V2V
communications equipment. This represents a classic ``collective
action'' problem, of the sort that government regulation is designed to
address. We do not believe that critical mass can be achieved, allowing
the life-saving benefits of V2V to come to fruition, in the absence of
a government mandate. We seek comment on these tentative conclusions.
    NHTSA received a number of comments to the ANPRM and the V2V
Readiness Report suggesting that V2V communication technology could be
better encouraged through what the agency refers to as an ``if-
equipped'' standard rather than a mandate for all new light vehicles--
i.e., that NHTSA should simply set a standard saying ``if a new vehicle
is equipped with devices capable of V2V communications, then it should
meet the following requirements.'' While both options are within the
agency's regulatory authority, we continue to believe that requiring
V2V communication technology for new light vehicles will be the
quickest and most effective way to achieve fleet-wide V2V communication
technology deployment and ensure the full safety potential of this
technology is realized.
    Allowing manufacturers to choose whether to apply V2V technology in
new vehicles could have two main risks in terms of holding back
potential safety benefits. First, it is uncertain how manufacturers
would voluntarily deploy V2V capability. Manufacturers typically have
implemented new vehicle-resident technologies in their more expensive
vehicles first. If manufacturers take this approach for V2V, NHTSA
believes that a segmented approach to implementation of V2V technology
will not be enough to quickly precipitate the data-rich environment
needed to support development of manufacturer-supplied safety
applications, or to support the needed establishment of a V2V
communications security system. Leaving the pace of that development to
the market will, we believe, delay the life-saving benefits of those
safety applications because the effectiveness of applications depends
on receiving messages from all other vehicles. Second, if fewer
vehicles are equipped with V2V, there may be less incentive for
industry to develop a sufficient security system, which will feed into
concerns from consumers regarding perceived potential privacy and
cybersecurity issues. Taken together, the delayed effectiveness of the
safety applications plus potentially increased concerns about security
may lead manufacturers not to include V2V capability in a significant
amount of vehicles at all. For these reasons, NHTSA proposes to require
new light vehicles to be V2V-capable.
    NHTSA and, we believe other stakeholders, will be working to
educate consumers about V2V, and will ensure that the V2V system is
designed to minimize security risks and protect privacy appropriately.
We believe consumer education will alleviate fear of the unknown as V2V
enters the vehicle fleet. Findings from our consumer research between
the ANPRM and this NPRM are discussed below in Section IV, and NHTSA
will be considering these issues carefully as we move forward.
    While we are proposing a V2V communications mandate, we also seek
further comment on the costs and benefits of an ``if-equipped'' option,
particularly considering the substantial monetary and potential social
costs of a mandate. Do commenters believe an if-equipped option would
be a preferable approach, and if so, why? What costs and/or benefits
should we consider relative to an if-equipped approach, and how do
those costs and benefits compare to our analysis of the costs and

benefits of a mandate? For instance, we seek additional comment on how
an if-equipped option may potentially delay or lead to uncertainty in
V2V technology development.
    In addition, what benefits may accrue from a more gradual, market-
based approach to a technology that has never before been widely
deployed? What affect would such an approach have on the ability to
iterate and test potential V2V technology solutions, including issues
related to costs, reliability, security, and deployment? How would an
if-equipped approach affect consumer choice and privacy protections? We
also seek examples and information related to the success and failure
of other network-reliant technologies, including those that evolved in
the absence of a government mandate and those that were mandated and
whether the example is applicable or not to a safety sensitive
function.

C. V2V Communication Devices That Would Be Subject to FMVSS No. 150

1. Original Equipment (OE) Devices on New Motor Vehicles
    NHTSA's research thus far indicates that V2V communications
technology is feasible for new light vehicles. The Safety Pilot Model
Deployment demonstrated that interoperability is possible and directly
informed the requirements in this proposed FMVSS and also in SAE
standards such as J2735 and J2945. The agency is confident that V2V
devices integrated into light vehicles consistent with these
requirements will provide the technical foundation for national
deployment of DSRC-based crash avoidance capability.
2. Aftermarket Devices
    Many consumers may not be ready to purchase a new vehicle, but may
be interested in having V2V capabilities in their current vehicles.
NHTSA believes that it is likely that aftermarket products may be
developed in response to consumer interest in V2V, and we strongly
support the innovation and accessibility that aftermarket devices could
foster, all potentially leading to expanded and earlier benefits from
V2V communication technology. As the name suggests, ``aftermarket''
refers to products that the vehicle owner purchases and adds to his or
her vehicle after the vehicle's manufacture. Aftermarket products are
distinguished from ``original equipment,'' which is installed on the
vehicle during its manufacture, prior to initial purchase. Allowing
aftermarket products to participate in the V2V system will enable the
technology to spread faster than if introduced through new vehicles
only--thus accelerating safety benefits.
    As part of setting standards for aftermarket V2V devices, however,
NHTSA recognizes that some aftermarket products may not be able to
populate optional BSM data elements if they do not have access to the
CAN bus. Aftermarket devices will therefore need to use other methods
to populate elements needed to calculate vehicle position in order to
support crash avoidance warnings. Some data elements, such as turn
signal indication, will not be able to be derived from other methods.
As a result, the inability of some aftermarket devices to populate
certain optional BSM data elements may impact the fidelity (ability to
balance the level of false positive warnings) of safety applications
that the aftermarket device supports. In the Safety Pilot Model
Deployment, there were three separate types of ``aftermarket''
devices--some that were fully integrated into the vehicle just like
original equipment; some that were connected to the vehicle for power,
but did not have access to the vehicle's data bus; and some that also
only connected for power, and could only transmit BSMs but could not
receive them and could not deliver crash avoidance warnings. Based on
the information we currently have before us, we think it is reasonable
to assume that these three types of aftermarket devices could be
available in the rulemaking timeframe.
    For example, OEMs may choose to offer their own aftermarket V2V
devices that can be retrofitted onto earlier vehicle models (retrofit
means the devices can interface with the vehicle data bus), made by
that OEM, at one of their retailers. For another example, V2V devices,
which are not unlike today's dedicated aftermarket navigation systems
(e.g., a Garmin or TomTom), could potentially be developed for drivers
to purchase and have installed. The agency also foresees the potential
for some form of a multi-use device containing a V2V-related
application (``app'') that could be brought into a vehicle (``carry-
in'') by a driver. A carry-in device could have the capacity to simply
send a BSM without providing any warnings to the driver or potentially
provide more capabilities in a potential V2V, or V2I, system. Moreover,
in the future, there could be yet other types of aftermarket devices
that have V2V capabilities not yet envisioned by NHTSA.
    NHTSA does not wish to limit the development of different types of
aftermarket devices, but we do seek to ensure that all devices
participating in the system perform at a minimum or better performance
level for V2V communication. This is important because, in order to
ensure safe and secure crash avoidance benefits, all BSMs transmitted
need to perform at a minimum performance level such that safety
applications can identify imminent crash situations and issue warnings
to the driver to avoid a crash. Therefore, the minimum performance
requirements need to be the same for all devices with provisions that
accommodates the optional data elements that can be used to perform
better than the minimum.
    The proposed requirements for any V2V devices recognize that, as
DOT discovered in the Safety Pilot Model Deployment, installation can
significantly impact how devices perform. The agency believes there is
high probability that a certified device installer could complete the
installation for aftermarket safety devices. It is imperative that all
V2V components be properly installed to ensure that an aftermarket
device functions as intended. Whereas some vehicle owners may choose to
replace their own brakes or install other components on their vehicles
themselves, installation requirements for aftermarket V2V devices may
not be conducive to a do-it-yourself approach. Improper installation of
a GPS antenna has the potential to affect the proper population of BSM
data elements. Faulty position data from a transmitting vehicle can
result in false warnings, improperly timed warnings, etc. Moreover, an
improperly installed aftermarket device may put all other V2V-equipped
vehicles it encounters at risk until the given vehicle stops
communicating, or until its messages are rejected for misbehavior.
    The agency seeks comment on the potential need for certification of
aftermarket V2V device installations. If so, please provide any
potential recommendations of appropriate retail outlets, the
certification mechanisms, and authorizers (vehicle manufacturers,
device manufacturers, device retailers, others) that should be
employed. Conversely, do commenters believe that future available
technology may allow consumers to self-install V2V devices such as web-
based tools, or other potential methods, that could verify accuracy of
an installation? Research supporting this possibility would be very
helpful.

D. Potential Future Actions

1. Potential Future Safety Application Mandate
    NHTSA has concluded that V2V communication technology combined with
V2V-based safety applications can provide significant safety benefits
and potentially help drivers avoid thousands of crashes per year. We
believe that by leading with a mandate for V2V communication
technology, NHTSA will be able to foster industry development and
deployment of new, beneficial safety applications. As previously
discussed in the V2V Readiness Report and in the above discussion
concerning the safety need, there are a number of these applications
that the agency believes could be ready to be deployed soon after a V2V
mandate is in effect. In particular, the agency has highlighted two
specific applications, IMA and LTA.
    The agency focused on these potential safety applications because
prototypes of these applications were used during Safety Pilot Model
Deployment, because we have sufficient data, and because they can be
effectively enabled only by V2V. IMA warns drivers of vehicles
approaching from a lateral direction at an intersection, while LTA
warns drivers of vehicles approaching from the opposite direction when
attempting a left turn at an intersection.
    As discussed in the V2V Readiness Report, the agency has and will
continue to investigate other potential V2V safety applications that
could be enabled by V2V communications.\115\ Depending on the market
penetration of applications in response to this proposed mandate of the
foundational V2V capability, the agency may later decide to mandate
some or all of the potential applications discussed in the Readiness
Report, and perhaps future applications yet to be developed. If
mandated in the future, applications would likely be incorporated into
NHTSA's regulations as FMVSSs, and in the interests of clarity, each
application mandate would likely be contained in its own FMVSS.
---------------------------------------------------------------------------

    \115\ Six potential applications were mentioned in particular:
IMA, FCW, DNPW, EEBL, BSW/LCW, and LTA.
---------------------------------------------------------------------------

    At this time, though, the agency does not have sufficient
information to include with this NPRM proposed test procedures or
performance standards for LTA and IMA or any other safety applications.
To that end, we request comment on any additional information or
research on IMA, LTA and any other applications that could inform and
support an agency decision regarding whether to mandate safety
applications with or shortly after a final rule requiring DSRC.
2. Continued Technology Monitoring
    NHTSA's proposal to mandate V2V communications capability for new
light vehicles is based upon the best currently-available scientific
data and information. Consistent with its obligations under Executive
Order (E.O.) 13563, Improving Regulation and Regulatory Review (Jan.
18, 2011), and E.O. 13610 on the retrospective review of regulations,
NHTSA will review relevant new evidence and may propose revisions to a
subsequent proposed or final rule as necessary and appropriate to
reflect the current state of the evidence to provide an effective
regulatory program. In obtaining that new evidence, NHTSA may consider
collections of information that may trigger the Paperwork Reduction
Act, and would notify the public of these collections through the
separate Federal Register Notices required under that Act. NHTSA may
also identify and pursue additional issues for new research or conduct
further research with regards to existing issues addressed in this
proposed rule. Such modifications may be necessary in the future to
accommodate new systems and technology designs, and the agency would
consider these modifications in consultation with the public through
the notice and comment rulemaking process. We acknowledge that the
research relevant for evaluating a new technology would vary depending
on the type of technology considered.

E. Performance Criteria for Wireless V2V Communication

    In order to ensure that vehicles broadcast basic safety messages to
support potential safety applications, the agency is proposing
performance requirements for DSRC-based V2V communications. As part of
this, the agency is also requesting comment on alternative
interoperable technology provisions that would allow other technologies
to satisfy the mandate, as long as they meet performance and
interoperability requirements, which are based on the capabilities of
today's DSRC-based V2V communications.
    The agency is proposing to require that V2V devices be capable of
broadcasting V2V messages in an interoperable manner, i.e., that
devices can both transmit and receive BSMs using V2V communications
from all other vehicles equipped with a V2V communications technology.
We believe that the requirements described below will ensure
interoperability. We aim to ensure a uniform method for sending basic
safety information about the vehicle. In this way, any vehicle seeking
to utilize the V2V information environment to deliver safety benefits
would have a known and uniform method for doing so.
    In order to create this uniform method, an FMVSS would need to
contain requirements in a few areas. First, it would need to establish
the content of the information to be sent to the surrounding vehicles
(by not only specifying the type of information to send, but also the
measuring unit for each information element and the level of precision
needed). Second, the FMVSS would need to specify requirements for the
wireless transmission of the content (i.e., how far, how often, etc.).
Third, we may need to specify a standard approach to authenticate V2V
messages that are received to improve confidence in message contents.
    In addition to those three points, the FMVSS would also need to
specify other aspects of performance for a V2V-communications system in
order to support full-scale deployment and enable full functionality
including security. The agency recognizes that some capabilities are
not necessarily needed to support operations during the first few years
of deployment, but would be required as the V2V vehicle fleet grows.
    First, the devices regardless of the communication technology used
would need a uniform method for dealing with possible occurrences of
high volumes of messages (e.g.., potentially reducing the frequency or
range of messages in high congestion situations. Second, to help
identify and reduce the occurance of misconfigured or malicious devices
transmitting BSM messages, the FMVSS may need to specify methods for
identifying misbehaving devices. Finally, to support the above
functions, vehicles in the V2V environment may need a methods for
communicating with security infrastructure such as a SCMS (e.g., in
order to obtain new security certificates or report misbehaving
devices, and receive information about misbehaving devices).
    In short, an FMVSS would explain: (1) What information needs to be
sent to the surrounding vehicles; (2) how the vehicle needs to send
that information; (3) how a vehicle validates and assigns confidence in
the information; and (4) how a vehicle makes sure the prior three
functions work in various operational conditions (i.e., broadcast under
congested conditions, manage misbehavior, and update security
materials). A variety of voluntary

standards cover many of these aspects of performance. Our proposal
below draws from these voluntary standards but also explains why a
particular threshold or requirements from a voluntary standard is
appropriate. Finally, we are proposing a test method for evaluating
many of these aspects of performance. Having a clear test method helps
inform the public as to how the agency would evaluate compliance with
any final FMVSS.
    Finally, we acknowledge that research is ongoing in a few of the
areas we discuss in this section. While research continues in these
areas, we have described for the public the potential requirements that
we are considering, and the potential test methods for evaluating
compliance with those requirements. We believe that the public comments
that we will receive in response (coupled with the agency's ongoing
research) will produce a robust record upon which the agency can make a
final decision.
1. Proposed Transmission Requirements
    Our purpose for proposing a standardized set of transmission
requirements is in line with our vision for V2V as an information
environment that safety applications can use. By creating a
standardized method for transmitting the basic safety message, we are
creating the information environment with one clear method for
accessing it. Our current belief is that anyone who wants to implement
safety applications should know how their system can obtain the V2V
information as an input for their application.
    In order to have a standardized method for transmitting the basic
safety message we believe that a few aspects of performance need
requirements. We tentatively believe that all devices should be
required to transmit:
     With a sufficient power/range to guarantee reaching other
DSRC devices, within a minimum radius, that would allow use of the
basic safety message information reliably;
     on the same channel, and support using the same data
rate(s); and
     at the times required for each data element so that people
who have applications know when it will have information.
(a) DSRC Transmission Range and Reliability
    In order to ensure that surrounding vehicles within a certain range
of each vehicle transmitting basic safety messages can reliability
receive the messages, The proposal includes requirements for the
transmission range of the messages. While the research to date has
included various specifications for the antenna (e.g., power,
polarization, location on the vehicle, etc.), we tentatively believe it
more appropriate to measure the ability of the vehicle to transmit the
packet to a specified device at a specified distance. In other words
this transmission range and reliability requirement employs a more
performance-oriented approach where our FMVSS would not specify
requirements for the antenna itself.
    By specifying the requirements in this fashion, we not only set
requirements that can more closely follow real-world conditions, but
also leave aspects of design open to manufacturer choice (e.g., antenna
location on the vehicle). Our method here would simply seek to ensure
that the transmission of the basic safety message travels the required
distance and is readable by another DSRC device at that range
(regardless of how the antenna is configured). Thus, we seek comment on
our proposal. We currently believe that specifying the following three
areas would be appropriate:
     The three-dimensional (latitudinal, longitudinal and
elevation) minimum range that the basic safety message transmission
would need to reach;
     a test device (and its specifications, e.g., its receive
sensitivity) for testing the range and the locations to measure
reception of the basic safety message; and
     the reliability of the reception of the basic safety
message (i.e., how often is the message dropped) based on packet error
rate (PER).
    In addition, our current belief is that the agency would not need
to establish specifications for the transmitting device itself. In
other words, we request comment on our current belief that the
following design-level requirements would not be necessary for an
FMVSS:
     Transmission power;
     antenna polarization; and
     antenna placement.
(1) Range
    A basic safety message needs to travel far enough to support
potential safety applications that we anticipate would take advantage
of the information available through DSRC communications. Aside from
the basic ``open air'' communication scenarios, it is important to also
consider whether devices will be able to communicate with others that
are on the same road but, perhaps, not at the same elevation or
approach angles (i.e., the road elevation may change).
(a) Longitudinal/Lateral Range
    Our strategy we considered regarding what minimum range requirement
we should include for transmitting the basic safety message was to
balance:
     The information needs for potential safety applications;
and
     technical capabilities demonstrated.
    In terms of information needs for the safety applications, our
research to date used a minimum 300 m transmission range--while
recognizing this range would diminish in urban and non ``open air''
environments. The applications tested in the Safety Pilot Model
Deployment assumed vehicles were transmitting basic safety messages at
the 300 m range. In particular, we believe that DNPW requires the
longest communication range for effective operation because it
addresses a crash scenario where two vehicles approach each other head-
on. Using the target range of 300 m, two vehicles approaching at 60 mph
would be afforded approximately 5.6 seconds for the DNPW application to
detect the crash scenario and issue a warning. Based on this
information, our current belief is that 300 m will serve the needs of
the anticipated safety applications.
    Based on the existing research, our proposal is to adopt 300 m as
the minimum transmission range. We believe that this supports the needs
of anticipated safety applications and can be operationally met given
current technological capabilities; as demonstrated in Safety Pilot
Model Deployment. Currently, we also do not anticipate any safety
application requiring more range than 300 m. Thus, we tentatively do
not see a reason to increase the minimum transmission range beyond 300
m.
    Finally, we have not included a maximum range limit. Maximum
transmission range can vary by the power of the transmission, and
environmental conditions. While our current proposed requirements do
not include establishing a maximum transmission range, we request
comment on whether such a limit would be appropriate in conjunction
with the other requirements the agency is considering.
    We ask for comment on this proposed minimum. Is there any reason
that the agency should require a maximum transmission range as well as
a minimum? Should the agency choose a different minimum range
requirement? What would be appropriate alternative minimum and maximum
transmission range values and why? Please provide data to support your
position.

(b) Elevation Transmission Performance
    In addition to the 2-dimension range of the basic safety message
transmission, we need to consider the potential changes in elevation on
roadways. Thus, in addition to establishing a minimum distance that the
basic safety message needs to travel, we also need to establish an
elevation angle that the message needs to travel.
    Safety applications may need information from vehicles at a higher
elevation (because of changes in the slope of the roadway, for
example). Thus, our current belief is that a proposal to regulate DSRC
radio performance should also evaluate whether a vehicle transmitting
the basic safety message can transmit said message at an angle that is
sufficient to cover potential roadway elevation changes.
    Our proposal would require that vehicles transmit the basic safety
message not only to 300 m around a vehicle (in all directions--i.e.,
360 degrees) but also at an elevation angle of +[hairsp]10 degrees and
-6 degrees. We think that the elevation angle range of +[hairsp]10 to -
6 degrees 360 degrees around the vehicle is an appropriate range to
ensure that the broadcast of the BSM can be received by vehicles in a
300m radius given most roadway characteristics such as changes in
roadway grade was what was used to demonstrate capability in Safety
Pilot Model Deployment. The agency is continuing to research a larger
range of elevation angle (+/-10 degrees) to determine actual
transmission coverage range. In particular, if the range would be
adequate to support transmission and reception of BSMs on roadway
grades up to 15 degrees, which is the current design maximum for many
States and localities (excluding San Francisco). However, currently it
is not practicable to test the +/-10 degree elevation angle range given
current testing equipment.
    We ask for comment on this proposed minimum. Should the agency
choose a different minimum elevation angle requirement? What would be
appropriate alternative minimum elevation angle range values and why?
Please provide data to support your position.
(2) Testing the Elevation Transmission Range
    In order to give context to our proposed requirement, we are also
describing the method the agency would use in assessing the elevation
angle range performance requirement (i.e., the test procedure and type
of test device). As discussed later in this document, the agency would
test these requirements using test devices located within a specified
area around the vehicle in a static test to determine whether the
vehicle's basic safety message transmissions can reach the required
range. In order to conduct this test, we need to define two pieces of
information:
     The important characteristics of the test device for the
purposes of evaluating this requirement; and
     the area around the vehicle where we can place this test
device.
(a) Test Device
    As further discussed in the test procedure section of this
document, we anticipate that our test method would specify various
aspects of the test device for the purposes of evaluating a vehicle's
DSRC radio performance. However, for the purpose of evaluating this
aspect (i.e., the transmission range) of DSRC radio performance, we
believe the receive sensitivity of the test device is the
characteristic that would need to be most clearly defined in order to
test the transmission range objectively.
    Based on the currently-available research, the agency would measure
this using a test device with a sensitivity of -92 dBm. We believe that
-92 dBm is an appropriate sensitivity for the test device receiving the
basic safety message during the test because -92 dBm generally models
what average devices (e.g., cell phones) use for their antenna
sensitivity. We believe that it is a reasonable assumption that a
vehicle seeking to obtain basic safety messages for its safety
applications would be designed with, at minimum, this level of
sensitivity.
    Further, our understanding is that -92 dBm falls on the less-
sensitive side of the range of an average wireless device's antenna
sensitivity. We believe that using a less sensitive device within that
range is appropriate in this instance because it means we are using a
more stringent test condition that is still within the range of an
average device antenna's sensitivity.
(b) Location of the Test Device
    In addition to specifying the device, we also believe it is
important to specify the location of the device relative to the vehicle
being tested. We are proposing to define a zone around the vehicle
where a test device is used to evaluate the ability of the vehicle to
receive the basic safety message. Currently, the proposed zone is
defined as 300 m 2-dimensional range with an elevation angle that can
be set at +[hairsp]10 degree and -6 degrees.
    For testing the 2-dimensional (longitudinal and lateral) range, the
agency would specify an area within a circle around the vehicle that we
may test. The test circle has the following characteristics:
     It is 1.5 m above the test surface.
     It is parallel to the test surface.
     It has a center point that is 1.5 m above the vehicle
reference point.\116\
---------------------------------------------------------------------------

    \116\ Vehicle reference point is the same point that we defined
in the basic safety message content requirements section, above.
---------------------------------------------------------------------------

     The circumference of the circle is any point at a 300 m
radius from its center point.
    In other words, when conducting the compliance test, the agency
test engineer may place the test device at any point that is 1.5 m
above the ground and within the area of a circle whose center point is
1.5 m above the vehicle reference point and whose radius is 300 m.
    For testing the elevation range of the vehicle's transmission, we
tentatively believe it is preferable to use two slightly different
evaluation methods for the upward elevation versus the downward range.
For the upward elevation range, our proposal is that the test engineer
may place the test device at any point along the following line:
     The line originates at a point that is 1.5 m above the
vehicle reference point.
     The line rises at a +10 degree angle from the test surface
\117\ proceeding in any direction around the vehicle.\118\
---------------------------------------------------------------------------

    \117\ Note the line originates at a point that is 1.5 m above
the test reference point, but (for simplicity) we are expressing the
angle of the line by referencing the test surface (i.e., the ground,
which is not where the line begins). The angle of the line could be
expressed by referencing any plane that is parallel to the test
surface.
    \118\ In other words, the line can travel in any direction (360
degrees) around the point 1.5 m above the vehicle reference point.
---------------------------------------------------------------------------

     The line terminates at any point that is directly above
the circumference of the circle used in the 2-dimentional range test.
    On the other hand, for testing downward elevation range, the agency
would place the test device at any point along the following line:
     The line originates at a point that is 1.5 m above the
vehicle reference point.
     The line falls at a -6 degree angle from the test surface
\119\ proceeding in any direction around the vehicle.\120\
---------------------------------------------------------------------------

    \119\ See similar note, above.
    \120\ See similar note, above.
---------------------------------------------------------------------------

     The line terminates at any point where it intersects the
test surface.
    Test the downward elevation at a point that is likely closer to the
vehicle than the upward elevation, we believe that this method would
relieve some test complexities while still ensuring

that the transmissions will reach surrounding vehicles under real-world
roadway elevation changes. Further, we believe that the locations
defined above (longitudinal, lateral, and elevation) establish the
limits of the potential test conditions in a way that would still
enable the agency to measure at the extremities of the proposed range
requirement.
    As noted above, testing the elevation range would enable NHTSA to
test for compliance at any point along those aforementioned lines.
While we believe that -92 dBm is an appropriate sensitivity for our
test device when it is located 300 m away from the tested vehicle, we
request comment on whether the test device should still have a
sensitivity of -92 dBm if NHTSA tests the vehicle performance closer to
the vehicle along the aforementioned elevation testing lines. What
would the appropriate function be to determine the sensitivity based on
the test device's location along those testing lines?
    We further request comment not only on the test method but also on
whether there are other aspects of the test that the agency would need
to define in order to clearly evaluate this aspect of performance.
(3) Reliability
    The agency is proposing to require that a message packet error rate
(PER) is less than 10%. We believe that 10% PER is an appropriate
threshold and that vehicles will still be able to receive the basic
safety messages so long as the PER is below 10%. The agency believes
the PER metric at the proposed rate fulfills the need to evaluate how
reliably a V2V device can transmit a message for a specified distance.
    The Packet Error Rate (PER) is one way of quantifying how reliably
a message can travel a given distance. In essence, it measures how
often (i.e., the percentage of) parts of the message (i.e., packets)
fail to make it to the destination. The research for V2V safety
applications to date assumes that vehicles are transmitting the basic
safety message to a range of at least 300 m around the vehicle with a
PER of less than 10%.
    A PER of less than 10% aligns with the ASTM standard E2213-03
(2003) <IP_ADDRESS> where ``(2) DSRC devices must be capable of transferring
messages to and from vehicles at speeds of 85 mph with a Packet Error
Rate (PER) of less than 10% for PSDU lengths of 1000 bytes and to and
from vehicles at speeds of 120 mph with a PER of less than 10% for PSDU
lengths of 64 bytes.'' As such, the agency believes this specification,
along with the agency's successful Safety Pilot Model Deployment work,
makes it appropriate to include this as part of the performance
requirements for DSRC devices. Overall, the agency did not observe any
dropped basic safety messages (i.e., message did not reach a vehicle
within range) due to a high PER, and we believe that the 10% PER
threshold will continue to be appropriate in a more full-scale
deployment. We request comment on our tentative conclusions and also
request comment on what other potential PER thresholds would be more
appropriate (and why).
(4) Aspects of Transmission Range Performance Indirectly Tested
    We currently believe that testing the range (both 2-dimensional and
elevation) and the reliability (PER) of the transmission with a
specified test device (-92 dBm) in specified locations is sufficient to
determine whether a vehicle would be able to deliver basic safety
messages to vehicles around it in the real world (i.e., it would be
sufficient for supporting the safety applications currently under
active development). However, we recognize that there are a few aspects
of performance covered by the V2V research to date that we have not
included in this proposal. Our tentative conclusion is that the
proposed requirements would cover these aspects of performance
indirectly. Further, we believe that Proposal A would avoid
unnecessarily restricting manufacturer design choices while still
ensuring that the vehicle achieve the safety purpose of transmitting
the basic safety message. These aspects of performance are:
     Antenna location on the vehicle;
     antenna polarization; and
     transmit power.
(a) Antenna Location on the Vehicle
    The agency and its research partners utilized antenna location
mounting requirements on vehicles used in the Safety Pilot Model
Deployment activity. However, our tentative conclusion is that it is
unnecessary to specify requirements for antenna location. The location
of the antenna on a vehicle can affect the ability of the vehicle to
transmit the basic safety message to all the necessary locations around
the vehicle. However, we believe that testing for reception of the
basic safety message at the aforementioned locations around the vehicle
would clearly show whether the location of the vehicle antenna is
installed at an appropriate location where the vehicle structure would
not interfere with the transmission of the basic safety message.
    If the antenna location is appropriate enough to transmit the basic
safety message to meet the needs of the safety applications, we
tentatively see no need to further restrict the location of the antenna
on the vehicle (as it is also an important styling decision for the
auto manufacturer). However, we request comment on this tentative
conclusion. Are there any reasons why the agency should establish
requirements for the antenna location on the vehicle? What would these
restrictions be? How can they be objectively defined on the vehicle?
What data supports your conclusions?
(b) Antenna Polarization
    We also tentatively believe that the agency does not need to
establish performance requirements for the transmitting antenna's
polarization. We are aware that the research to date generally
recommended a nominal vertical polarization configuration for the DSRC
antennas sending the basic safety message. The research recommended
that configuration because vehicle sheet metal can serve as the ground
plane and can degrade reception of horizontally polarized waves at or
near the horizon.
    While we agree that using a non-optimal antenna polarization would
lead to increased cost and complexity of the system (i.e., requiring
more antennas in order to reach the same transmission coverage), we
tentatively do not believe it is necessary to propose limiting such a
design. We believe that, for cost considerations, manufacturers are
likely to select an antenna polarization that would enable them to
achieve the same performance with less antennas. However, so long as
the vehicle can transmit the basic safety message to the required range
under the conditions specified, we currently see no reason to preclude
other antenna polarizations. We also request comment on this tentative
conclusion.
(c) Transmit Power
    Finally, the requirements and test method also do not directly test
for the transmit power. Our current belief is that our test method
sufficiently covers this aspect of performance by establishing the
range at which the vehicle needs to transmit the basic safety message
and the receive sensitivity of the test device. We note that the
research to date has recommended various transmission power levels. For
example, the SAE J2945/1 standard recommended a minimum radiated power
of 15 dBm (under uncongested condtions). However, we believe that our

aforementioned requirements would sufficiently test for this aspect of
performance. In essence, by testing whether a device with a sensitivity
of -92 dBm can receive messages from a vehicle 300 m away, we are
testing whether the transmitting vehicle is doing so with sufficient
power to deliver the basic safety message to the required distance.
    We currently do not believe it is necessary to further specify the
transmit power for vehicles covered by the proposal. Based on the
manufacturer's choices regarding antenna location on the vehicle (and
potentially other factors such as the body of the vehicle, etc.), a
manufacturer may need to make different transmit power choices in order
to transmit the message to the required distance. As with antenna
location and polarization, we believe that the transmission power is
sufficiently addressed (albeit indirectly) by the requirements. We
believe that the requirements would establish an appropriate balance
between affording the manufacturers design freedom, while still
ensuring that they achieve the safety goal of transmitting the basic
safety message far enough and reliably enough to support the safety
applications. We seek comment on whether there is any reason for the
agency to establish a requirement for the transmit power. What should
the transmission power be and why?
(5) FCC Transmission Power Restrictions
    The agency's proposal is not specifying required transmission power
levels for V2V devices. The FCC places restrictions on the transmission
power levels of devices utilizing a given spectrum and our expectation
is that DSRC devices operating in the designated bandwidth would meet
the FCC defined operating specifications. However, we do not believe
that our current proposal (i.e., our proposed minimum transmission
range and the sensitivity of the test device) would require vehicles to
transmit at a power that exceeds FCC regulations.
    FCC Part 95L specifies a max EIRP limit of 33dBm for Private OBUs
on channels 172, 174, 176, 178, and 184. Our understanding is that
devices would be able to meet the these requirements at a power setting
lower than the restricted level (Safety Pilot Model Deployment devices
were set at a 20 dBm power level).
(b) Channel and Data Rate
    In addition to proposing requirements for the transmission range
and reliability, we believe it is also important for DSRC-based V2V
communications to utilize the same channel and data rate. The channel
is a band of frequencies where the transmission occurs. Parties
agreeing to use the same channel to communicate are like people that
agree to call each other using a particular phone line. The data rate
is the speed at which a sender is transmitting information through the
channel.
    The FCC has statutory authority for allocating spectrum rights and
designating band plans for commercial spectrum allocations, including
the 5.9 GHz band. DOT defers to the FCC's authority with respect to
spectrum rights and channel plans. Based on FCC rules and research to-
date, all devices participating in the V2V information environment have
utilized the same channel and data rate to transmit BSMs. In relation
to DSRC, FCC has specified that BSM transmissions and reception will
occur on channel 172, i.e. channel 172 will be dedicated to all BSM
communications (safety-critical communications). Therefore, throughout
this document, references to BSM transmissions and reception will refer
to channel 172 while also recognizing the ongoing DOT-FCC-NTIA spectrum
sharing studies and the FCC rulemaking concerning the 5.9 GHz band as
described in more detail below. Similar to our approach to transmission
power, the agency believes that all BSM transmissions should occur on
channel 172. Data rate is also important because a receiving device
needs to know the speed at which the transmitting device is sending the
information in order to process the information. Thus, in order to
ensure interoperability of the devices in the V2V information
environment, our current belief is that it is necessary to establish
requirements for both the channel and the data rate.
    As we discuss below, there are various options for both the channel
and the data rate--each with advantages and disadvantages. While there
are different choices available, each choice should be able to achieve
the objective of ensuring interoperability across devices if it is
implemented consistently by all devices. Thus, we are proposing to that
all vehicles should transmit the basic safety message on Channel 172,
via a dedicated radio at a data rate of 6 Mbps). We also request
comment on whether there are other choices for these two aspects of
performance that the agency should consider.
(a) Channel
(i) Proposed Channel Usage
    The FCC currently divides the 5.9 GHz spectrum into seven, ten-
megahertz channels consisting of one Control Channel (Channel 178); six
Service Channels (Channel 172 for safety-critical communications and
Channels 174, 176, 180, 182, and 184 for non-safety-critical
communications); and one five megahertz channel, which would be held in
reserve. The FCC also allows combining Channels 174 and 176 or Channels
180 and 182 to produce two twenty-megahertz channels, (which would be
Channel 175 and 181, respectively).
    As we discussed in the sections above, we believe that devices
participating in the V2V information environment need exchange messages
on the same channel in order to receive each other's broadcasts (i.e.,
to hear the messages that others send). Up until now, the V2V devices
transmitting basic safety messages in the V2V research have used
Channel 172 (a 10 MHz channel). The research used a 10 MHz channel as
the FCC's current rules for the V2V spectrum divide it into various 10
MHz channels.
    Our tentative conclusion is that broadcasting on Channel 172 via
continuous mode (radio set to channel 172, a 10 MHz band) is
appropriate for devices in the V2V information environment. Thus, we
believe that all vehicles should transmit their basic safety messages
on the same channel (172). Our tentative conclusion is based on our
understanding of the existing research and in alignment with the FCC
spectrum allocation. The agency expects that all non-safety-critical
communications will occur on the remaining channels allocated for DSRC
use by the FCC. The research suggests that a 10 MHz band is sufficient
for transmitting the basic safety message to the necessary 300 m range
at a sufficient level of reliability PER of less than or equal to 10%.
    We seek comment on all related issues we should take into account
when considering this proposal, as well as any other potential
alternatives.
(ii) Potential Channel Sharing or Re-channelization
    NHTSA and the U.S. DOT are committed to finding the best method to
develop, successfully test, and deploy advanced automotive and
infrastructure safety systems while working to meet existing and future
spectrum demands. DOT supports sharing so long as it does not interfere
with safety of life communications. In the summer of

2015, recognizing the emerging need to perform further research on DSRC
properties in order to prepare for studies on sharing, DOT worked
collaboratively with the FCC and NTIA to develop a spectrum research
plan. This plan (the ``DSRC-Unlicensed Device Test Plan'') is posted on
DOT's Web site and details a comprehensive set of research
opportunities. The plan will allow FCC, NTIA, and DOT to collectively
tailor research on DSRC devices in the presence of unlicensed devices
to understand the prospective impacts within real-world
environments.\121\ The overall goals and objectives of this research
are as follows:
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    \121\
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     Overall Goals as listed in the DSRC-Unlicensed Device Test
Plan
    1. Understand the impacts of unlicensed devices operating in the
DSRC band.
    2. Develop the capability to evaluate proposed band sharing
mechanisms.
    3. Define requirements necessary for sharing mechanisms to prevent
interference.
    4. Collaborate with the NTIA and FCC to provide Congress with
results on impacts to DSRC operations from proposed sharing mechanisms.
     Specific Objectives and Goals as listed in the DSRC-
Unlicensed Device Test Plan
    1. Develop the capability to do accurate and relevant experimental
evaluations of band sharing and interference between unlicensed devices
and DSRC devices.
    2. Characterize the existing radio frequency (RF) signal
environment in and near the DSRC band.
    3. Measure the effect of unlicensed devices on the background noise
level.
    4. Measure the impact unlicensed device transmissions have on
receiving DSRC messages.
    5. Measure DSRC suppression caused by Clear Channel Assessment
(CCA) of DSRC devices in the presence of unlicensed device
transmissions.
    6. Measure other impacts on DSRC channel quality of unlicensed
device transmissions (e.g., signal to noise (S/N), packet error rate
(PER), etc.).
    7. Determine the minimum received power levels at which DSRC and
unlicensed devices can sense the other.
    8. Investigate how interference and detection (determined in the
previous objectives) varies if the bandwidth of the overlapping
unlicensed device transmission changes.
    9. Measure the impact of DSRC operations on unlicensed device
performance recognizing that the two radios may form an interactive
system.
    10. Investigate mitigation possibilities once potential U-NII-4
devices designed and programmed to share the band with DSRC are
available.
    This DOT testing effort is part of a larger collaborative testing
and modelling effort with the FCC and DOC, encouraged by Congress, to
ensure appropriate interference-avoidance and spectrum rights
allocation in the 5850-5925 MHz (5.9 GHz) band. Congress called upon
DOT to lead, in close coordination with FCC and DOC, the development of
5.9 GHz Dedicated Short Range Communications (DSRC) technology, vehicle
safety testing, and DSRC capabilities testing. Furthermore, Congress
called upon NTIA to study the possibility of allowing unlicensed
operations in the 5.9 GHz band. The U.S. Department of Transportation
(DOT), the U.S. Department of Commerce (DOC), and the Federal
Communications Commission (FCC) each have core, yet interdependent,
roles to play in advancing this research.
    Recently, the FCC issued a Public Notice to refresh its record
regarding its draft proposal to allow sharing of the 5.9 GHz band by U-
NII devices.\122\ As part of its Public Notice, the FCC has solicited
comments on the two proposed sharing techniques developed by the IEEE
DSRC Coexistence Tiger Team (i.e., ``Detect and Avoid'' and ``Re-
Channelization''), as well as on other potentially viable approaches to
sharing in the band without causing harmful interference to V2V
operations.
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    \122\ https://apps.fcc.gov/edocs_public/attachmatch/FCC-16-68A1_Rcd.pdf.
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    The FCC described the two proposed sharing approaches as follows:
(1) Detect and avoid, under which unlicensed devices would monitor the
existing DSRC channels, and if they detected any transmitted DSRC
signal, they would avoid using the entire DSRC band. After waiting a
certain amount of time the unlicensed device would again sense the DSRC
spectrum to determine if any DSRC channels are in use or whether it
could safely transmit; and (2) Re-Channelization, under which the DSRC
spectrum would be split into two contiguous blocks: one for safety-
related communications and one for non-safety-related communications,
by moving the control channel and the two public safety channels to the
top portion of the band. Additionally, the remaining four DSRC service
channels would be reconfigured at the lower end of the band as two 20
megahertz channels rather than maintaining four 10 megahertz channels.
The segments designated for safety-related communications would remain
exclusive to DSRC, and the remaining spectrum would be shared between
the DSRC service channels and unlicensed devices.
    We seek comment on the costs and benefits of each sharing proposal,
and whether and how we should consider each of these approaches
relative to this proposed rule.
(b) Data Rate
    In setting a data rate, one is balancing between two competing
interests: (1) the speed at which one wants to transmit the
information, and (2) how far the information can travel (and how
reliably it can travel that distance). In other words, if we send more
information in a smaller amount of time, the information cannot
reliably travel as great of a distance.
    In the context of our rulemaking, our proposal for data rate
considers the following technical questions:
     How far do we need the message to travel?
     What is an acceptable PER (i.e., how reliably do packets
need to make it to a receiving device in order to ensure that a safety
application can function)?
     What bitrate do current systems and voluntary standards
under development use? If a final rule used a different set of
requirements, how significant would this change be?
    In the sections that follow, we first discuss the competing
considerations for our data rate proposal. Using the information that
we have from our discussion on data rate, we then discuss our proposal
for the channel.
(i) Proposed Requirement is 6 Mbps
    The agency is proposing to require devices to transmit at 6 Mbps.
We believe it is reasonable to expect that transmitting basic safety
messages at the 6 Mbps rate can easily cover the necessary range
assuming 300 m at a very low PER of 10%. The available research from
both CAMP and BAH support this initial conclusion, as described later
in this section. Further, while we are requesting comment on changing
the bitrate, we note that the current systems and voluntary standards
under development all will be able to support multiple bitrates within
the ranges examined (i.e., device developers would not need to redesign
the current hardware to support a new bitrate).
    Finally, while the theoretical analysis by BAH suggests that
increasing the bitrate would help to mitigate congestion mitigation, we
are unsure given the lack of real-world testing whether altering the
bitrate and channel bandwidth is necessary given that the agency is
considering other channel

congestion mitigation strategies. These strategies involve adjusting
the number of basic safety messages that devices would transmit per
second and the power/range of those transmission when channel
congestion is detected by a device. More detail on these strategies is
found in Section III.E.1.b)(b)(ii). The agency is continuing to refine
congestion mitigation approaches including device density in real-world
conditions, beyond those tested in the specific Safety Pilot testing
and Safety Pilot Model Deployment.
    We request comment on our potential approaches to conclusions and
our questions above. To support the commenting process, we are also
presenting alternative choices for bitrate in the section that follows
and we seek comment on those alternatives.
(ii) Alternatives for Data Rate Requirements
    The BAH research suggested alternate bitrate possibilities that
would change based on the level of congestion on the channel. Their
rationale behind this approach is that, when the channel is not busy,
the transmitting device should use a lower bitrate that can more
reliably send the message. However, when the channel congestion is
detected, the device should use a higher bitrate to send the message
quicker and vacate the channel as soon as possible. This is a logical
strategy because when a vehicle is in a congested environment (e.g., a
traffic jam \123\); the vehicle does not need to transmit the message
as far because the relevant cars are the ones that are fairly close by.
In other words, in this scenario, it is important to transit the
message fast (not far).
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    \123\ In relation to communications congestions the use of the