Interactions with Advanced In-Vehicle Information and Communication
Systems,'' p. 63, June 26, 2006 version, Alliance of Automobile
Manufacturers, Washington, DC.
---------------------------------------------------------------------------

3. Suggestion That the NHTSA Guidelines Should Recommend That All
Devices can be Disabled
a. Summary of Comments
    In their commentary, automakers consistently argued that their
customers generally demand that they have the ability to perform an
increasing variety of secondary tasks while driving. The National
Safety Council (NSC) provided an opposing perspective in the following
comments:

    Some comments submitted to NHTSA advocate for making it easy for
drivers to conduct information-gathering, social media and other
communication tasks in their vehicles because there's a belief that
consumers demand and expect this. Consumers who know better may
demand the opposite. The National Safety Council's employer members
who have implemented total cell phone bans when their employees are
driving understand the risks of cognitive distraction. There are
individuals and organizations that may not want the distraction of
in-vehicle systems.\325\
---------------------------------------------------------------------------

    \325\ Comments received from The National Safety Council, p. 5.
Accessed at www.regulations.gov, Docket NHTSA-2010-0053, Document
Number 0085.

    Based on the foregoing, the NSC recommended that NHTSA incorporate

---------------------------------------------------------------------------
the following additions to the guidelines:

    A requirement that vehicle owners be able to turn off all
systems not essential to the driving task or the safe operation of
the vehicle.\326\
---------------------------------------------------------------------------

    \326\ Ibid, p. 10.
---------------------------------------------------------------------------

    An encouragement or requirement for the auto industry to install
technologies that prevents cell phones and other electronic devices
that are brought into the vehicle from being used by the driver
while the vehicle is [in] motion.\327\
---------------------------------------------------------------------------

    \327\ Ibid, p. 10.
---------------------------------------------------------------------------

b. NHTSA's Response
    In response to NSC's suggestion, NHTSA has added a recommendation
to its Driver Distraction Guidelines that every electronic device not
essential to the driving task or the safe operation of the vehicle have
a means for turning off or otherwise disabling the device. While the
vast majority of electronic devices already have an on/off control or
some other means of disablement, NHTSA thinks that all devices
providing non-safety-related information should have such a feature.
    NHTSA is not prepared at this time to expand this recommendation to
one that vehicle owners be able to turn ``Off'' all electronic devices
not essential to the driving task or the safe operation of the vehicle
(and driver is not able to turn the devices back on). This idea is not
unlike that of Ford Motor Company's MyKey[supreg] system. MyKey[supreg]
allows parents to program their teenage driver's car key with settings
that limit the vehicle's speed, prevent safety systems from being
disabled, and beginning in 2012 on some vehicles, cause incoming phone
calls to be sent automatically to voicemail and incoming text messages
to be saved for later reading. While NSC's idea may have merit, NHTSA
is not prepared to act on it at this time.
    Finally, establishing a requirement to install technologies to
prevent cell phones and other technologies from being used by the
driver will need further research before NHTSA can consider adding such
a recommendation to the NHTSA Guidelines.

V. Statutory Considerations

    Under the National Technology Transfer and Advancement Act of 1995
(NTTAA) (Pub. L. 104-113), ``all Federal agencies and departments shall
use technical standards that are developed or adopted by voluntary
consensus standards bodies, using such technical standards as a means
to carry out policy objectives or activities determined by the agencies
and departments.'' Voluntary consensus standards are technical
standards (e.g., materials specifications, test methods, sampling
procedures, and business practices) that are developed or adopted by
voluntary consensus standards bodies, such as SAE and ISO. The NTTAA
directs us to provide Congress, through OMB, explanations when we
decide not to use available and applicable voluntary consensus
standards.
    Pursuant to these requirements, NHTSA, with the help of commenters,
has identified a number of voluntary consensus standards related to
distracted driving. After careful consideration, the agency is
incorporating several of these standards into the test methods
contained in the NHTSA Guidelines: ISO International Standard
15008:2003, ``Road vehicles--Ergonomic aspects of transport information
and control systems--Specifications and compliance procedures for in-
vehicle visual presentation''; ISO International Standard
16673:2007(E), ''Road Vehicles--Ergonomic Aspects of Transport
Information and Control Systems--Occlusion Method to Assess Visual
Demand due to the use of In-Vehicle Systems''; and multiple versions of
SAE Recommended Practice J941, ``Motor Vehicle Drivers' Eye
Locations,'' including SAE J941 (June 1992), SAE J941 (June 1997), SAE
J941 (September 2002), SAE J941 (October 2008), and SAE J941 (March
2010). The agency has included an explanation for its decision to use
these standards in the discussions on the per se lock out related to
reading, the occlusion field factor, and the downward viewing angle
recommendations.
    The agency considered the possibility of using other voluntary
consensus standards cited by commenters. However, we have found these
standards to be unsuitable for the NHTSA Guidelines. Our analysis of
these voluntary consensus standards can be found in Section IV.A.4 of
this preamble.

Guidelines for Reducing Visual-Manual Driver Distraction during
Interactions with Integrated, In-Vehicle, Electronic Devices

I. PURPOSE.

    The purpose of these Guidelines is to reduce the number of motor
vehicle crashes and the resulting deaths and injuries that occur due
to a driver being distracted from the primary driving task while
performing secondary tasks involving the use of an in-vehicle
electronic device. The Guidelines are presented as an aid to
manufacturers in designing in-vehicle devices that do not allow the
performance of tasks that negatively impact a driver's ability to
safely control his or her vehicle. Vehicle and electronic device
manufacturers that choose to adhere to these Guidelines do so
voluntarily. Compliance with these Guidelines is not required.

A. Driver Responsibilities.

    These Guidelines do not alter the driver's primary
responsibility to ensure the safe operation of a vehicle as governed
by the state laws under which it is being operated, both while
driving and when interacting with in-vehicle electronic devices.
This includes following all traffic laws, obeying traffic control
devices, and driving in a safe manner under all operating
conditions.

B. Protection Against Unreasonable Risks to Safety.

    The National Highway Traffic Safety Administration (NHTSA) does
not evaluate the safety implications of every new device before it
is introduced into vehicles. However, the Safety Act authorizes
NHTSA to initiate enforcement action when a motor vehicle or item of
motor vehicle equipment, including original equipment in-vehicle
electronic devices, contains a safety-related defect. (49 U.S.C.
30118-30121).

II. SCOPE.

    These Guidelines are applicable to the human-machine interfaces
of electronic devices used for performing all non-driving-related
tasks \328\ as well as for performing some driving-related tasks.
---------------------------------------------------------------------------

    \328\ Underlined terms are defined in Section IV. Definitions.
---------------------------------------------------------------------------

    Table 2 contains a non-exhaustive list of the types of non-
driving-related tasks and electronic devices to which these
Guidelines are applicable.

  Table 2--Non-Driving-Related Tasks/Devices To Which These Guidelines
                                  Apply
------------------------------------------------------------------------
             Type of task                         Task/Device
------------------------------------------------------------------------
Communications.......................  Caller Identification
                                       Incoming Call Management
                                       Initiating and Terminating Phone
                                        Calls
                                       Conference Phoning
                                       Two-Way Radio Communications
                                       Paging
                                       Address Book
                                       Reminders
                                       Text-Based Communications
                                       Social Media Messaging or Posting
Entertainment........................  Radio (including but not limited
                                        to AM, FM, and Satellite)
                                       Pre-recorded Music Players, All
                                        Formats
                                       Television
                                       Video Displays
                                       Advertising
                                       Internet Browsing
                                       News
                                       Directory Services
Information..........................  Clock
                                       Temperature
------------------------------------------------------------------------

    These Guidelines are applicable to driving-related tasks that
are neither related to the safe operation and control of the vehicle
nor involve the use of a system required by law. Examples of
driving-related tasks to which these Guidelines are applicable
include interacting with vehicle information centers, emissions
controls, fuel economy information displays, trip odometers, and
route navigation systems. These Guidelines are not applicable to the
following general categories of driving-related tasks, which involve
activities performed by the driver as part of the safe operation and
control of the vehicle or involve systems required by law:
     Operating the driving controls (steering wheel,
throttle pedal, brake pedal, etc.) of the vehicle,
     Any task relating to proper use of a driver safety
warning system,
     Using any other electronic device that has a function,
control, and/or display specified by either a Federal Motor Vehicle
Safety Standard, another United States Government law or regulation,
or a state or local Government law or regulation.
    A non-exhaustive list of driving-related task categories, along
with whether these Guidelines apply to each category, is contained
in Table 3.

                     Table 3--Driving-Related Tasks
------------------------------------------------------------------------
                                             Guidelines applicable?
  Categories of driving-related tasks  ---------------------------------
                                              Yes               No
------------------------------------------------------------------------
Manipulating the steering handwheel...  ...............               X
Applying the brake, throttle, and       ...............               X
 clutch pedal (if present)............
Operating the transmission shift lever  ...............               X
Operation of paddle shifters on         ...............               X
 steering wheel.......................
Operation of the parking brake........  ...............               X
Turning headlights on or off..........  ...............               X
Adjustment of instrument panel          ...............               X
 brightness...........................
Turning turn signals on or off........  ...............               X
Operation of windshield wipers........  ...............               X
Operation of the horn.................  ...............               X
Locking and/or unlocking doors........  ...............               X
Operation of moveable windows.........  ...............               X
Adjustment of moveable mirrors........  ...............               X
Looking at inside and outside rearview  ...............               X
 mirrors..............................
Turning blind spot detector on or off.  ...............               X
Operation of moveable seats and         ...............               X
 headrests............................
Operation of seat belts...............  ...............               X
Checking the speedometer, fuel gauge,   ...............               X
 engine temperature gauge and any
 other gauges or digital displays
 presenting information that is
 necessary for the safe operation of
 the vehicle..........................
Checking telltale and malfunction       ...............               X
 indicators...........................
Turning electronic stability control    ...............               X
 and/or traction control on or off....
Adjustment of climate controls not                   X   ...............
 required by a Federal Motor Vehicle
 Safety Standard (e.g., temperature
 and fan adjustment)..................
Operation of cruise control...........               X   ...............
Performance of a task via multi-                     X   ...............
 function display interface...........
Resetting trip odometers and/or trip                 X   ...............
 computers............................
Navigation of the vehicle--Destination               X   ...............
 entry................................
Navigation of the vehicle--Route                     X   ...............
 following............................
Real-Time Traffic Advisory............               X   ...............
Trip Computer Information.............               X   ...............
Observation of vehicle information                   X   ...............
 centers..............................
Observation of emissions controls.....               X   ...............

Observation of fuel economy displays..               X   ...............
Adjusting vehicle suspension and/or                  X   ...............
 ride.................................
------------------------------------------------------------------------

A. Guidelines Intended for Human-Machine Interfaces

    These Guidelines are applicable primarily to human-machine
interfaces of in-vehicle electronic devices intended for use by a
driver. They are applicable to a limited extent (see Section VII) to
devices intended for use by front seat passengers of a vehicle. They
are not applicable to devices that are located solely rearward of
the front seat of a vehicle.

B. Only Device Interfaces Covered

    These Guidelines are not applicable to any aspect of covered
electronic devices other than their interfaces. Specifically, they
do not cover a device's electrical characteristics, material
properties, or performance.

C. Original Equipment Electronic Devices Covered

    These Guidelines are applicable to the human-machine interfaces
of original equipment electronic devices (i.e., those built into a
vehicle at the time of manufacture). These Guidelines are applicable
to such devices even when linked with aftermarket or portable
devices, i.e., original equipment devices should control all
aftermarket and portable devices linked to them (i.e.,
electronically connected with some type of data exchange) in
accordance with these principles.

D. Aftermarket and Portable Devices Not Covered

    These Guidelines are currently not applicable to the human-
machine interfaces of electronic devices that are either installed
into a vehicle after it is manufactured (aftermarket devices) or are
brought into the vehicle on a temporary basis by the driver or
passengers (portable devices).

E. Device Tasks Performed Via Auditory-Vocal Means Not Covered

    These Guidelines are currently not applicable to the auditory-
vocal portions of human-machine interfaces of electronic devices.

F. Intended Vehicle Types

    These Guidelines are applicable to passenger cars, multipurpose
passenger vehicles, and trucks and buses with a Gross Vehicle Weight
Rating (GVWR) of not more than 10,000 pounds. However, these
guidelines are not applicable to:
    1. Ambulances or combination ambulance-hearses,
    2. Firefighting vehicles,
    3. Military vehicles,
    4. Vehicles manufactured for use by the United States Government
or a State or local government for law enforcement, or
    5. Vehicles manufactured for other emergency uses as prescribed
by regulation by the Secretary of Transportation.

III. STANDARDS INCLUDED BY REFERENCE

    The following standards and all of their provisions are used in
these Guidelines.

 A. International Organization for Standardization (ISO) Standards

    ISO 15008:2003, ``Road vehicles--Ergonomic aspects of transport
information and control systems--Specifications and compliance
procedures for in-vehicle visual presentation,'' March 2003.
    ISO 16673:2007(E), ``Road vehicles--Ergonomic aspects of
transport information and control Systems--Occlusion method to
assess visual demand due to the use of in-vehicle systems,'' April
2007.

B. SAE International (SAE) Standards.

    SAE Recommended Practice J941, ``Motor Vehicle Drivers' Eye
Locations.'' Any of the following versions of SAE J941 are
acceptable: SAE J941 (June 1992), SAE J941 (June 1997), SAE J941
(September 2002), SAE J941 (October 2008), or SAE J941 (March 2010).

IV. DEFINITIONS.

A. General Definitions.

    1. Active Display Area means the portion of a visual display
used to present information to the driver in the context of any task
that makes use of that display. It excludes unused display surface
and any area containing physically-manipulatable controls.
    2. Device means all components that a driver uses to perform
secondary tasks (i.e., tasks other than the primary task of safe
operation and control of the vehicle); whether stand-alone or
integrated into another device.
    3. Distraction means the diversion of a driver's attention from
activities critical for safe operation and control of a vehicle to a
competing activity.
    4. Downward Viewing Angle means the angle by which a driver has
to look down from the horizontal to directly glance at a device's
visual display. Both a three-dimensional downward viewing angle and
a two-dimensional approximation are used in these Guidelines.
    5. Driver's Field of View means the forward view acquired
directly through the windshield, rear, and side views acquired
through the other vehicle windows, as well as the indirect side and
rear views provided by the vehicle's mirrors.
    6. Driving means whenever the vehicle's means of propulsion
(engine and/or motor) is activated unless one of the following
conditions is met:
    a. For a vehicle equipped with a transmission with a ``Park''
position--The vehicle's transmission is in the ``Park'' position.
    b. For a vehicle equipped with a transmission without a ``Park''
position--All three of the following conditions are met:
    i. The vehicle's parking brake is engaged, and
    ii. The vehicle's transmission is known (via direct measurement
with a sensor) or inferred (by calculating that the rotational speed
of the engine divided by the rotational speed of the driven wheels
does not equal, allowing for production and measurement tolerances,
one of the overall gear ratios of the transmission/vehicle) to be in
the neutral position, and
    iii. The vehicle's speed is less than 5 mph.
    7. Driving-Related Task means:
    a. Any activity performed by a driver as part of the safe
operation and control of the vehicle (not covered by these
Guidelines),
    b. Any activity performed by a driver that relates to use of a
vehicle system required by Federal or State law or regulation (not
covered by these Guidelines), or
    c. Any other activity performed by a driver that aids the driver
in performing the driving task but is not essential to the safe
operation or control of the vehicle (covered by these Guidelines).
    8. Function means an individual purpose which the device is
designed to fulfill. A device may have one or more functions.
    9. Glance means a single ocular fixation by a driver. If the eye
glance characterization method being used cannot distinguish between
different nearby locations of individual fixations, ``glance'' may
also be used to refer to multiple fixations to a single area that
are registered as one ocular fixation.
    10. Glance Duration means the time the gaze moves towards a
target (the transition time) and the dwell time (the time fixated on
a particular point) on the target. Glance duration does not include
the transition time away from the target. (This is part of the next
glance.)
    11. Graphical or Photographic Image means any non-video
graphical or photographic image. Internationally standardized
symbols and icons, as well as TrademarkTM and
Registered[supreg] symbols, are not considered graphical or
photographic images.
    12. Interaction means an input by a driver to a device, either
at the driver's initiative or as a response to displayed
information. Interactions include control inputs and data inputs
(information that a driver sends or receives from the device that is
not intended to control the device). Depending on the type of task
and the goal, interactions may be

elementary or more complex. For the visual-manual interfaces covered
by this version of these Guidelines, interactions are restricted to
physical (manual or visual) actions.
    13. Lock Out means the disabling of one or more functions or
features of a device so that the related task cannot be performed by
the driver while driving.
    14. Manual Text Entry means manually inputting individual
alphanumeric characters into an electronic device. For the purposes
of these Guidelines, digit-based phone dialing is not considered
manual text entry.
    15. Nominal Driver Eye Point means the assumed (for these
Guidelines) location of the center of the driver's eyes.
    16. Non-Driving-Related Task means any activity performed by a
driver other than those related to the driving task. A non-
exhaustive list of non-driving-related tasks is contained in Table
2. These Guidelines are applicable to all non-driving-related tasks
performed using electronic devices.
    17. Per Se Lock Out means the lock out of a function or feature
due to its inherent interference with a driver's ability to operate
and control a vehicle safely.
    18. Reading means the driver's act of perceiving visually
presented textual information. Reading does not include a driver's
perception of auditorily presented text.
    19. Subtend means, in a geometrical sense, to be opposite to and
delimit (an angle or side).
    20. Text-Based Messaging means manually inputting individual
alphanumeric characters into, or reading from, an electronic device
for the purpose of present or future communication. This action
includes, but is not limited to, the composition or reading of
messages transmitted via short message service, email, instant
messaging service, internet-based messaging, or social media
internet-based applications (including posting). Text-based
messaging does not include:
    a. Reading, selecting, or entering a phone number, an extension
number, or voice-mail retrieval codes and commands into an
electronic device for the purpose of initiating or receiving a phone
call or using voice commands to initiate or receive a phone call; or
    b. Using a device capable of performing fleet management
functions (e.g., dispatching services) for a purpose that is not
otherwise prohibited by law.
    21. Video means full-motion visual information presented through
electronic means. This includes entertainment, advertising, and
other visual content not related to driving that is obtained from
pre-recorded images, live images, video games, broadcasts (such as
by television or over the internet), and/or closed-circuit
television.

B. Task-Related Definitions.

    1. Control Input means a driver action to the human-machine
interface of an electronic device that is intended to affect the
state of that device. Control inputs may be initiated either by a
driver or as a driver's response to displayed information initiated
by a device. For the visual-manual interfaces covered by these
Guidelines, control inputs are restricted to manual control actions.
    2. Dependent Task means a task that cannot be initiated until a
prior task (the antecedent task) is first completed. The task's
start state is thus dependent upon the end state of the antecedent
task.
    An antecedent task followed by a dependent task can be
distinguished from a single task that contains two subtasks by
examining the end states of the two tasks or subtasks. For the
antecedent task-dependent task case, both tasks' goals can be
achieved (i.e., one goal for the antecedent task and one goal for
the dependent task). In contrast, for a task composed of two
subtasks, only one goal will be achieved.
    An example of an antecedent task-dependent task: after choosing
a restaurant from a navigation system's point-of-interest list
(antecedent task with goal of choosing a restaurant), a driver is
offered an internet function option of making a reservation at the
restaurant (dependent task with goal of making reservation). Since
there are two goals, this is an antecedent task followed by a
dependent task. The dependent task of making a reservation can only
be initiated following the task of selecting a restaurant from
within the navigation system.
    An example of multiple subtasks: entering an address into a
route navigation system. The driver enters first the state, then the
city, then the street, and finally the street number into the
navigation system. However, the driver only has one goal for all of
these actions: to enter the complete address. The entry of the
state, city, street, and street number are all subtasks since they
each form a part of achieving this one goal.
    3. End of Data Collection means the time at which a test
participant informs the experimenter they have completed a testable
task either by speaking the word, ``done'' or, by a non-verbal means
(such as a button press) indicating the same thing. Test participant
eye glances are not examined after the end of data collection. If a
test participant eye glance was in progress at the end of data
collection, only the portion that occurred before the end of data
collection is used. Successful task completion requires that the
device is in the desired end state at the end of data collection.
    4. End State for a Testable Task means the pre-defined device
state sought by a test participant to achieve the goal of that
testable task.
    5. Error means that a test participant has made a significant
incorrect input when performing a testable task during a test trial.
An error has occurred if the test participant has to backtrack
during performance of the task or delete already entered inputs. If
the device can accommodate an incorrect entry without requiring
backtracking and extra inputs beyond those necessary to reach the
desired end state of the task, then no error is deemed to have
occurred.
    6. Error-Free Trial means a test trial in which no errors are
made by the test participant while completing the task.
    7. Goal means a device state sought by a driver. Goal
achievement is defined as achieving a device state that is the
driver's intended state. Goals are frequently independent of the
particular device hardware and software being used to execute the
task or the method of task execution.
    8. Secondary Task means any interaction a driver has with an in-
vehicle device that is not directly related to the primary task of
the safe operation and control of a vehicle. These tasks may relate
to driver comfort, convenience, communications, entertainment,
information seeking, or navigation.
    9. Start of Data Collection means the time when the experimenter
instructs a test participant to begin a task using a verbal cue,
``begin'' (or issues a non-verbal command indicating the same
thing). Test participant eye glances are examined only after the
start of data collection. If a test participant eye glance was in
progress at the start of data collection, only use the segment after
the start of data collection. The start of data collection should
occur when the device is at the pre-defined start state for a
testable task.
    10. Start State for a Testable Task means the pre-defined device
state from which testing of a testable task always begins. This is
frequently the ``home'' screen, default visual display state, or
other default human-machine interface state from which a driver
initiates performance of the testable task. For dependent tasks, the
start state would be the end state of the previous testable task.
    For a testable task for which there is only one point (e.g.,
screen, visual prompt, step) from which the task can be initiated,
that point would correspond to the start state. For a testable task
which can be initiated from more than one point, one of these
options is selected as the start state. If it can be determined
which start state occurs most often during normal driving, testing
should commence from that start state. (The desire here is to reduce
the amount of testing needed to ensure adherence with these
Guidelines. It is generally not necessary to test all possible
transitions into a testable task.)
    11. Sub-goal means an intermediate state on the path to the
driver's goal. A sub-goal is often distinguishable from a goal in
two ways: (1) it is usually not a state at which a driver would be
satisfied stopping; and (2) it may vary in its characteristics and/
or sequential order with other sub-goals across hardware/interface
functions, and thus is system dependent.
    12. Subtask means a sub-sequence of control operations that is
part of a larger testable task sequence--and which leads to a sub-
goal representing an intermediate state in the path to the larger
goal toward which a driver is working.
    Subtasks should not be treated as separate dependent tasks. For
example, entering the street name as part of navigation destination
entry is not a separate task from entering the street number;
rather, these are subtasks of the same testable task.
    Data collection should only be undertaken for all subtasks as a
group, which comprises a testable task. Separate data collection for
individual subtasks is not appropriate.
    13. Successful Task Completion means that a test participant has
performed a testable task without significant deviations from the
correct sequence(s) of inputs (i.e., made an error) and achieved the
desired end state. As explained earlier, an error has occurred if
the

test participant has to backtrack during performance of the task or
delete already entered inputs. If the device can accommodate an
incorrect entry without requiring backtracking and extra inputs
beyond those necessary to reach the desired end state of the task,
then no error is deemed to have occurred.
    14. Testable Task means a pre-defined sequence of interactions
performed using a specific method leading to a goal toward which a
driver will normally persist until the goal is reached. A testable
task begins with the device at a previously defined start state and
proceeds, if successfully completed, until the device attains a
previously defined end state. It is called a testable task because
it is a completely defined secondary task that can be tested for
adherence with these Guidelines.

C. Task-Related Explanatory Material.

    1. Testable tasks should be completely defined prior to any
testing to determine whether they are suitable to perform while
driving under these Guidelines. The task's goal, start state, end
state, specific method to be used, and inputs should all be
specified.
    2. For testable tasks with a variety of possible inputs of
different lengths (e.g., city names for navigation systems), a
typical or average length input should be used. Precise mean values
need not be used and there may be some variation in length from
input-to-input. For example, for the input of city names into a
navigation system, lengths of 9 through 12 letters might be used.
    3. For testable tasks that involve reading, nearby text
unrelated to the task being performed should not be considered part
of the text that is to be read during the testable task.
    4. For the purposes of acceptance testing, text unrelated to the
task and the labels of buttons or controls need not be included as
part of the text that is read during a testable task.

V. DEVICE INTERFACE RECOMMENDATIONS.

    Each device's human-machine interface should meet the
recommendations specified below.

A. No Obstruction of View.

    1. No part of the physical device, when mounted in the manner
intended by the manufacturer, should obstruct a driver's view of the
roadway.
    2. No part of the physical device, when mounted in the manner
intended by the manufacturer, should obstruct a driver's view of any
vehicle controls or displays required for driving.

B. Easy to See and Reach.

    The mounting location for a device should be in a location that
is easy to see and/or reach (as appropriate) while driving.

C. Maximum Display Downward Angle.

    Each device's display(s) should be mounted in a position where
the downward viewing angle, measured at the geometric center of each
active display area, is less than at least one of the following two
angles:
     The 2D Maximum Downward Angle, or
     The 3D Maximum Downward Angle.
    The values of these maximum angles depend upon the location of
the nominal driver eye point as follows:
    1. Location of the nominal driver eye point. The method used for
calculating the location of the nominal driver eye point varies
depending upon which version of SAE Recommended Practice J941
``Motor Vehicle Drivers' Eye Locations'' is being used. If the June
1992, June 1997, September 2002, or October 2008 version of SAE J941
is being used, then the nominal driver eye point is located 8.4 mm
above and 22.9 mm rearward of the mid-eye centroid of the SAE
eyellipse. If the March 2010 version of SAE J941 is being used, then
the nominal driver eye point is located at the mid-eye centroid of
the SAE eyellipse.
    2. The 2D Maximum Downward Angle is equal to 30.00 degrees for a
vehicle with the height of the nominal driver eye point less than or
equal to 1700 millimeters above the ground.
    3. The 2D Maximum Downward Angle is given by the following
equation for nominal driver eye point heights greater than 1700
millimeters above the ground:

[theta]2DMax= 0.01303 hEye + 15.07
where

[theta]2DMax is the 2D Maximum Downward Angle (in degrees), and
hEye is the height above the ground of the nominal driver eye point
(in millimeters).

    4. The 3D Maximum Downward Angle is equal to 28.16 degrees for a
vehicle with the height of the nominal driver eye point less than or
equal to 1146.2 millimeters above the ground.
    5. The 3D Maximum Downward Angle is given by the following
equation for nominal driver eye point heights greater than 1146.2
millimeters above the ground:

[theta]2DMax = 57.2958 tan-1 [0.829722 tan(0.263021 +
0.000227416 hEye)]
where

[theta]2DMax is the 3D Maximum Downward Angle (in degrees), and
hEye is the height above the ground of the nominal driver eye point
(in millimeters).
    6. The downward viewing angle of each display is determined in
two ways, two dimensionally (the 2D Downward Viewing Angle) and
three dimensionally (the 3D Downward Viewing Angle).
    7. Determination of 2D Downward Viewing Angle. Create a fore-
and-aft plane (Plane FA) through the nominal driver eye point.
Define Point B as the laterally projected (while maintaining the
same fore-and aft and vertical coordinates) position of the
geometric center of the display of interest onto Plane FA. Generate
two lines in Plane FA, Line 1 and Line 2. Line 1 is a horizontal
line (i.e., maintaining the same vertical coordinate) going through
the nominal driver eye point. Line 2 goes through the nominal driver
eye point and Point B. The 2D Downward Viewing Angle is the angle
from Line 1 to Line 2.
    8. Determination of 3D Downward Viewing Angle. Generate two
lines, Line 3 and Line 4. Line 3 is a horizontal line (i.e.,
maintaining the same vertical coordinate) going through the nominal
driver eye point and a point vertically above, below, or at, the
geometric center of the display of interest. Line 4 goes through the
nominal driver eye point and the geometric center of the display.
The 3D Downward Viewing Angle is the angle from Line 3 to Line 4.
    9. Visual displays that present frequently needed and/or
important information during the driving task and/or visually-
intensive information should have downward viewing angles that are
as close as practicable to a driver's forward line of sight. Visual
displays that present less frequently needed or less important
information should have lower priority, when it comes to locating
them to minimize their downward viewing angles, than displays that
present frequently needed and/or used information.

D. Lateral Position of Visual Displays.

    Visual displays that present information relevant to the driving
task and/or visually-intensive information should be laterally
positioned as close as practicable to a driver's forward line of
sight.

E. Minimum Size of Displayed Textual Information.

    Visually presented text should meet the legibility
recommendations contained in ISO International Standard 15008:2003,
``Road vehicles--Ergonomic aspects of transport information and
control systems--Specifications and compliance procedures for in-
vehicle visual presentation.''

F. Per Se Lock Outs.

    The following electronic device tasks are recommended for per se
lock out and should always be inaccessible for performance by the
driver while driving:
    1. Device functions and tasks not intended to be used by a
driver while driving.
    2. Manual Text Entry. Manual text entry by the driver for the
purpose of text-based messaging, other communication, or internet
browsing.
    The following electronic device tasks are recommended for per se
lock out and should always be a) inaccessible for performance by the
driver while driving and b) inaccessible for performance by a
passenger if the related display is within view of the driver
properly restrained by a seat belt:
    3. Displaying Video. Displaying (or permitting the display of)
video including, but not limited to, video-based entertainment and
video-based communications including video phoning and
videoconferencing.
    Exceptions:
    a. The display of video images when presented in accordance with
the requirements of any FMVSS.
    b. The display of a video image of the area directly behind a
vehicle for the purpose of aiding a driver performing a maneuver in
which the vehicle's transmission is in reverse gear (including
parking, trailer hitching), until any of the following conditions
occurs:
    i. The vehicle reaches a maximum forward speed of 10 mph;
    ii After the vehicle has shifted out of reverse, it has traveled
a maximum of 10 meters; or

    iii. After the vehicle has shifted out of reverse, a maximum of
10 seconds has elapsed.
    c. Map displays. The visual presentation of dynamic map and/or
location information in a two-dimensional format, with or without
perspective, for the purpose of providing navigational information
or driving directions when requested by the driver (assuming the
presentation of this information conforms to all other
recommendations of these Guidelines). However, the display of
informational detail not critical to navigation, such as
photorealistic images, satellite images, or three-dimensional images
is not recommended.
    4. Displaying Images. Displaying (or permitting the display of)
non-video graphical or photographic images.
    Exceptions:
    a. Displaying driving-related images including maps (assuming
the presentation of this information conforms to all other
recommendations of these Guidelines). However, the display of map
informational detail not critical to navigation, such as
photorealistic images, satellite images, or three-dimensional images
is not recommended.
    b. Static graphical and photographic images displayed for the
purpose of aiding a driver to efficiently make a selection in the
context of a non-driving-related task (e.g., music) is acceptable if
the image automatically extinguishes from the display upon
completion of the task. If appropriate, these images may be
presented along with short text descriptions that conform to these
Guidelines.
    c. Internationally standardized symbols and icons, as well as
Trademark \TM\ and Registered[supreg] symbols, are not considered
static graphical or photographic images.
    5. Automatically Scrolling Text. The display of scrolling
(either horizontally or vertically) text that is moving at a pace
not controlled by the driver.
    6. Displaying Text to Be Read. The visual presentation of the
following types of non-driving-related task textual information:

 Books
 Periodical publications (including newspapers, magazines,
articles)
 Web page content
 Social media content
 Text-based advertising and marketing
 Text-based messages (see definition) and correspondence

    However, the visual presentation of limited amounts of other
types of text during a testable task is acceptable. The maximum
amount of text that should be visually presented during a single
testable task is determined by the task acceptance test protocols
contained in these Guidelines.

G. Acceptance Test-Based Lock Out of Tasks.

    Any non-driving-related task or within-scope (identified as
Guidelines Applicable in Table 3 of Section II), driving-related
task that diverts a driver's attention from the primary driving task
to the point it does not conform with one of the task acceptance
methods contained in Section VI, should be locked out while driving.

H. Sound Level.

    Devices should not produce sound levels likely to mask warnings
either from within or from outside the vehicle, or that cause
distraction. The device sound level control should demonstrate its
ability to adjust sound levels down to a fully muted level.

I. Single-Handed Operation.

    Devices should allow a driver to maintain at least one hand on
the vehicle's steering control. All tasks that require manual
control inputs (and can be performed with the device while the
vehicle is in motion) should be executable by a driver in a way that
meets all of the following criteria:
    1. When manual device controls are placed in locations other
than on the steering control, no more than one hand should be
required for manual input to the device at any given time during
driving.
    2. When device controls are located on the steering wheel and
both hands are on the steering wheel, no device tasks should require
simultaneous manual inputs from both hands.
    3. A driver's reach to the device's controls should allow one
hand to remain on the steering control at all times.
    4. Reach of the whole hand through steering wheel openings
should not be required for operation of any device controls.

J. Interruptibility.

    Devices should not require uninterruptible sequences of visual-
manual interactions by a driver. A driver should be able to resume
an operator-interrupted sequence of visual-manual interactions with
a device at the point of interruption or at another logical point in
the sequence.
    1. Except as stated in Subsection V.J.5, below, no device-
initiated loss of partial driver input (either data or command
inputs) should occur automatically.
    2. Drivers should be able to initiate commands that erase driver
inputs.
    3. A visual display of previously-entered data or current device
state should be provided to remind a driver of where the task was
left off.
    4. If feasible, necessary, and appropriate, the device should
offer to aid a driver in finding the point to resume the input
sequence or in determining the next action to be taken. Possible
aids include, but are not limited to:
    a. A visually displayed indication of where a driver left off,
    b. A visually displayed indication of input required to complete
the task, or
    c. An indication to aid a driver in finding where to resume the
task.
    5. Devices may revert automatically to a previous or default
state without the necessity of further driver input after a device
defined time-out period, provided:
    a. It is a low priority device state (one that does not affect
safety-related functions or way finding), and
    b. The state being left can be reached again with low driver
effort. In this context, low driver effort is defined as either a
single driver input or not more than four presses of one button.
    6. This subsection is not applicable to device output of
dynamically changing data. The device should control the display of
information related to dynamic events that are not within the
driver's direct control (e.g., distance to the next turn).

K. Device Response Time.

    1. A device's response (e.g., feedback, confirmation) following
driver input should be timely and clearly perceptible.
    2. As a ``best practice,'' the maximum device response time to a
device input should not exceed 0.25 seconds. The measurement of this
time should begin starting at the completion of the driver's control
input.
    3. If a device's response time exceeds 2.00 seconds, a clearly
perceptible indication should be given indicating that the device is
responding. Again, the measurement of this time should begin
starting at the completion of the driver's control input.
    4. The device's response is clearly perceptible if it is obvious
to the driver that a change has occurred in the device and that this
change is the consequence of the input. If this change in the device
resulting from an input is not always the same but depends on one or
more previous inputs, it would be advisable to offer help (i.e.,
provide help if requested by the driver).

L. Disablement.

    1. Devices providing non-safety-related information should
provide a means by which the device can be turned off or otherwise
disabled.
    2. Devices providing dynamic (i.e., moving) non-safety-related
visual information should provide a means by which that information
cannot be seen by the driver. A device visually presenting dynamic
non-safety-related information should make the information not
visible by the driver through at least one of the following
mechanisms:
    a. Dimming the displayed information,
    b. Turning off or blanking the displayed information,
    c. Changing the state of the display so that the dynamic, non-
safety-related information cannot be seen by a driver while driving,
or
    d. Positioning or moving the display so that the dynamic, non-
safety-related information cannot be seen while driving.

M. Distinguish Tasks or Functions Not Intended for Use While Driving.

    Devices should clearly distinguish between those aspects of a
device that are intended for use by a driver while driving, and
those aspects (e.g., specific functions, menus, etc.) that are not
intended to be used while driving.

N. Device Status.

    Information about current status and any detected malfunction
within the device that is likely to have an adverse impact on safety
should be presented to the driver.

VI. TASK ACCEPTANCE TESTING.

    One of the following methods is recommended for task acceptance
testing:
     Eye Glance Measurement Using Driving Simulator Testing
(described in Subsection VI.E, below), or

     Occlusion Testing (described in Subsection VI.G,
below).

A. Test Participant Recommendations.

    1. These Test Participant recommendations apply to both Eye
Glance Measurement Using Driving Simulator Testing and Occlusion
Testing.
    2. General Criteria. Each test participant should meet the
following general criteria:
    a. Be in good general health,
    b. Be an active driver with a valid driver's license,
    c. Drive a minimum of 3,000 miles per year,
    d. Have experience using a cell phone while driving,
    e. Be unfamiliar with the device(s) being tested.
    3. Test Participant Impartiality. Test participants should be
impartial with regard to the testing. To ensure fairness, test
participants should not have any direct interest, financial or
otherwise, in whether any of the devices being tested meets or does
not meet the acceptance criteria.
    a. NHTSA will not use any vehicle manufacturer employees in its
Guidelines monitoring testing.
    b. NHTSA considers it acceptable for vehicle manufacturers to
test their own employees as long as the employees are unfamiliar
with the product being tested.
    4. Mix of Ages in Each Test Participant Sample. Out of each
group of 24 test participants used for testing a particular in-
vehicle device task, there should be:
    a. Six test participants 18 through 24 years old, inclusive,
    b. Six test participants 25 through 39 years old, inclusive,
    c. Six test participants 40 through 54 years old, inclusive, and
    d. Six test participants 55 years old or older.
    5. Even Mix of Genders in Each Test Participant Sample. Each
sample of 24 test participants used for testing a particular in-
vehicle device task, should contain:
    a. Twelve men and twelve women overall, and
    b. An equal balance of men and women in each of the age ranges
18 through 24 years old, 25 through 39 years old, 40 through 54
years old, and 55 years old and older.

B. Test Participant Training Recommendations.

    Each test participant should be given training as to how to
operate the driving simulator or occlusion apparatus and how to
perform each of the desired testable tasks using the electronic
devices being evaluated.
    1. These Test Participant Training recommendations apply to both
Eye Glance Measurement Using Driving Simulator Testing and Occlusion
Testing.
    2. Test instructions should be standardized and be presented
either orally or in writing. The display and controls of the
interface should be visible during instruction. An instruction may
be repeated at the request of a test participant.
    3. Test participants should be given specific detailed
instructions and practice as to how to perform each testable task of
interest on each device being studied. A test participant should
practice a task as many times as needed until they think that they
have become comfortable in performing the task.
    4. Test participants should practice each testable task on each
device of interest first without using the acceptance test apparatus
and then using the acceptance test apparatus.

C. Driving Simulator Recommendations.

    1. A driving simulator is used for the Eye Glance Measurement
Using Driving Simulator Testing option to determine whether driver
operation of a device while performing a testable task produces an
acceptable level of distraction. At a minimum, the driving simulator
used for distraction testing should conform to the following
recommendations. However, any driving simulator with better fidelity
than recommended below is acceptable for performing task acceptance
testing.
    2. The driving simulator should be capable of testing using a
substantial portion (the entire area that can be reached by a
driver) of a full-size vehicle cab. Open cabs, partial cabs, and/or
non-production cabs are fine to use for this testing as long as the
driving simulator has a seating and dashboard arrangement similar to
that of an actual production vehicle so that realistic eye glance
behavior and control movements will occur.
    3. To set up this portion of a vehicle cab for testing, no
modifications should be made to the dashboard or human-machine
interface other than:
    a. The addition of sensors to determine steering wheel angle,
brake pedal position, throttle pedal position, driver gaze location,
and other desired data.
    b. The addition of equipment to provide force feedback on the
driving simulator's steering wheel, brake pedal, and throttle pedal.
Linear feel steering and pedal feels are adequate.
    c. The addition of equipment to display the forward speed to the
driver. This may be accomplished either through use of the vehicle's
speedometer or through a separate display. If forward speed is
provided to the driver through a separate display, this display may
be mounted:
     On the image display in front of the simulated vehicle,
or
     On or above the dashboard.
    4. The driving simulator should use information collected by the
steering wheel angle, brake pedal position, and throttle pedal
position sensors, along with an appropriate vehicle dynamics
simulation, to predict vehicle orientation and position, angular and
linear velocities, and angular and linear accelerations. A vehicle
dynamics model with three degrees of freedom (lateral velocity,
longitudinal velocity, and yaw rate) may be used. If more complex
and accurate vehicle dynamics are desired, this is fine but not
necessary.
    5. The driving simulator should determine eye glance locations
in one of two ways:
    a. Through the use of an eye tracker, or
    b. By collecting full-motion video data for each test
participant's face and, subsequent to testing, a human data reducer
determines from the video data the direction of a test participant's
gaze at each instant in time.
    Additional details about eye glance characterization are
presented below.
    6. The driving simulator should generate and display full-color
(16 bit minimum color depth), true-perspective, three-dimensional
(as viewed by the driver) computer-generated imagery of the forward
road scene free from distracting anomalies, such as abrupt changes
in scene content, aliasing problems in image processing, and abrupt
changes in illumination, color, or intensity (i.e., no flickering or
flashing).
    7. This computer-generated imagery should be displayed in front
of the simulated vehicle. The minimum recommended field-of-view
should have a width of at least 30 degrees.
    8. The recommended screen resolution should be no greater than 3
arc minutes per pixel.
    9. The recommended driver eye point to screen distance should be
at least 2.0 meters.
    10. The computer generated image should be updated at least 30
times per second.
    11. The time lag to calculate the computer generated imagery
should not be more than 0.10 second. As a ``best practice,'' lead
compensation should be provided to bring the driving simulator
display into phase with the driver's perception.
    12. The driving simulator should be capable of simulating the
driving scenario described below.

D. Recommended Driving Simulator Scenario.

    The driving simulator scenario described below is used for the
Eye Glance Measurement Using Driving Simulator Testing option.
    1. The road being simulated should:
    a. Traverse generally open, flat terrain with occasional trees
or buildings,
    b. Be made of asphalt,
    c. Be light gray in color,
    d. Be undivided, four lanes wide, and have at least 1.0 meter
(3.3 feet) of paved shoulders on each side of the traffic lanes,
    e. Each lane should be 3.7 meters (12 feet) wide,
    f. Have a solid double yellow line down the center of the road,
    g. Have solid white lines on the outside edges of the road,
    h. Have dashed white lines separating the two lanes that go in
the same direction on each side of the road,
    i. Be flat (no grade or road crown), and
    j. Have a speed limit of 50 mph.
    k. Each of the above white and yellow lines on the road should
be from approximately 100 mm to approximately 150 mm (4 to 6 inches)
wide.
    l. For the solid double yellow line, the spacing between the two
yellow lines should be from approximately 50 mm to approximately 100
mm (2 to 4 inches) wide.
    m. The dashed white lines should each consist of a white/asphalt
pattern consisting of approximately a 3 meter (10 foot) white line
segment followed by approximately a 9 meter (30 foot) gap of asphalt
before the beginning of the next white segment.
    n. All test data collection is performed on straight road
segments. However, the road

being simulated may, if desired, contain occasional curved segments
not in the area used for data collection.
    2. The lead vehicle should look like a typical, production,
passenger vehicle (automobile or light truck) and be of a color that
contrasts with the background.
    3. The driving scenario should proceed as follows:
    a. The subject vehicle begins motionless in the right lane of
the road.
    b. Test participant accelerates vehicle up to approximately the
speed limit.
    c. After approximately 360 meters (1,200 feet) of travel, the
lead vehicle, which is initially traveling at the speed limit,
suddenly appears in the travel lane in front of the subject vehicle
at a distance of approximately 70 meters (220 feet).
    d. The subject vehicle then follows the lead vehicle for the
remainder of the test. This is defined as the car following portion
of the test.
    e. During the car following portion of the test, the driver of
the subject vehicle should try to maintain a following distance of
approximately 70 meters (220 feet).
    4. All testing is performed while driving in the right lane of
the simulated road.
    5. A test participant should begin performing testable tasks as
soon as feasible after the start of the car following portion of the
test.
    6. The speed of the lead vehicle should be a constant 50 mph
throughout the car following period of the test.

E. Eye Glance Measurement Using Driving Simulator Test Procedure.

    1. Test Device. The electronic device under evaluation should be
operational and fitted to a vehicle, driving simulator, or vehicle
mock-up in a design which duplicates the intended location of the
interface in the vehicle (i.e., the viewing angle and control
placement relationships should be maintained).
    2. Test Participants. Twenty-four test participants should be
enrolled using the previously described (Subsection VI.A) criteria.
    3. Each test participant should have the driving simulator's
controls and displays explained to him or her, and be shown how to
adjust the seat.
    4. Each test participant should be given instructions on the
driving scenario that he or she is to perform. These should include:
    a. That he or she should drive in the right lane, and
    b. That, as a driver, his or her primary responsibility is to
drive safely at all times.
    5. Each test participant should be told to drive at a speed of
50 mph prior to the beginning of car following. Each test
participant should be told that, once in car following mode, he or
she should try to follow the lead vehicle at as close to the initial
following distance (approximately 70 meters or 220 feet) as he or
she can manage.
    6. Each test participant should be given training and practice
as follows:
    a. How to perform each testable task on each device of interest
with the simulated vehicle parked. This training and practice may
also be performed in a separate parked vehicle.
    b. How to drive the driving simulator while not performing a
testable task.
    c. How to perform each testable task on each device of interest
while driving the simulated vehicle on the driving simulator.
    7. Each test participant should practice each testable task and
simulator driving as many times as needed until he or she become
comfortable in performing the task and driving the simulator.
    8. Different task stimuli (e.g., addresses, phone numbers, etc.)
should be used for each instance of testable task performance for a
particular test participant. Task stimuli should be provided to a
test participant immediately prior to the beginning of each instance
of testable task performance.
    9. Following the completion of training, each test participant
should drive the driving scenario one final time while performing a
single instance of the testable task being studied (the Data Trial).
Eye glance data should be collected during this trial. Data from
this performance of the testable task is used to determine whether a
task meets the acceptance criteria.
    10. Results from individual testable task trials are only
removed from analysis if:
     A test participant refuses to complete a trial,
     A test participant says he or she is done with a trial
but is not, or
     The experimenter judges that the participant cannot
successfully complete a trial.
     The experimenter judges that the participant is not
genuinely doing their best to perform the protocol and related tasks
as instructed.
    When any of the above occurs, it is treated as a task
performance error and handled as discussed in Subsection VI.H.
    11. There should be a means of determining the exact time of the
start and end of each testable task that is performed.
    12. Multiple Testable Task Testing. To improve testing
efficiency, multiple (different) testable tasks may be performed by
the same test participant during one or more drives. There is no
limit to the number of testable tasks that may be evaluated by a
test participant.
    13. Eye Glance Characterization. Eye glances are determined for
each test participant's Data Trials using the techniques described
below.
    14. Acceptance Criteria. A testable task should be locked out
from performance by drivers while driving unless the following three
criteria are all met:
    a. For at least 21 of the 24 test participants, no more than 15
percent (rounded up) of the total number of eye glances away from
the forward road scene have durations of greater than 2.0 seconds
while performing the testable task one time.
    b. For at least 21 of the 24 test participants, the mean
duration of all eye glances away from the forward road scene is less
than or equal to 2.0 seconds while performing the testable task one
time.
    c. For at least 21 of the 24 test participants, the sum of the
durations of each individual participant's eye glances away from the
forward road scene is less than or equal to 12.0 seconds while
performing the testable task one time.

F. Eye Glance Characterization.

    While driving the simulator and performing the testable task,
the duration of each test participant's eye glances away from the
forward roadway should be recorded and determined.
    1. The duration of an individual glance is determined as the
time associated with any eye glances away from the forward roadway.
Due to the driving scenario, eye glances to the side of the roadway
or to the vehicle's mirrors are expected to be minimal.
    2. Eye glance durations should be determined in one of two ways:
    a. Through the use of an eye tracker, or
    b. By collecting full-motion video data for each test
participant's face and, subsequent to testing, a data reducer
determines from the video data the direction of a test participant's
gaze at each instant in time.
    3. Ensuring Eye Tracker Accuracy and Repeatability. If an eye
tracker is used, the testing organization should have a procedure
for ensuring the accuracy and repeatability of eye glance durations.
This will require collecting relatively short segment(s) of full-
motion video data and having a data reducer determine from this
video data the duration of a test participant's eye glances. The
testing organization should also have a written procedure for
setting up and calibrating the eye tracker.
    4. Ensuring Full-Motion Video Reduction Accuracy and
Repeatability. If full-motion video is used, the testing
organization should have a procedure for ensuring the accuracy and
repeatability of eye glance durations. This will involve having
multiple data reducers analyze the same, relatively short segment(s)
of full-motion video data and checking that they obtained the same
glance durations. The testing organization should also have a
written procedure for instructing and training data reducers as to
how to determine eye glance durations. To the extent possible, data
reducers should not have an interest as to whether a testable task
or device being tested meets the acceptance criteria. Data reducers
should not be closely involved with the development of a device.

G. Occlusion Testing.

    1. Test Apparatus. Intermittent viewing of an electronic device
interface can be provided by a variety of means such as
commercially-available occlusion goggles, a shutter in front of the
interface, or other means.
    a. The occlusion apparatus used should be transparent during the
viewing interval and opaque during the occlusion interval.
    b. The occlusion apparatus should be electronically controlled.
    c. During the occlusion interval, neither the electronic device
interface displays nor the device controls should be visible to a
test participant.
    d. During the occlusion interval, operation of the device
controls by a test participant should be permitted.
    e. The switching process between the viewing interval and the
occlusion interval should occur in less than 20 milliseconds and
vice versa.
    2. Test Device. The electronic device under evaluation should be
operational and fitted to

a vehicle, driving simulator, or vehicle mock-up in a design which
duplicates the intended location of the interface in the vehicle
(i.e., the viewing angle and control placement relationships should
be maintained).
    3. Test Participants. Twenty-four test participants should be
enrolled using the previously described (Subsection VI.A) criteria.
    4. Each test participant should be given training and practice
as follows:
    a. How to perform each testable task on each device of interest
without using the occlusion apparatus.
    b. How to drive the occlusion apparatus while not performing a
testable task.
    c. How to perform each testable task on each device of interest
while using the occlusion apparatus.
    5. Each test participant should practice each testable task and
use of the occlusion apparatus as many times as needed until he or
she becomes comfortable in performing the task and using the
occlusion apparatus.
    6. Different task stimuli (e.g., addresses, phone numbers, etc.)
should be used for each instance of testable task performance for a
particular test participant. Task stimuli should be provided to a
test participant immediately prior to the beginning of each instance
of testable task performance.
    7. Test Procedure. Testing is performed in accordance with ISO
International Standard 16673:2007(E), ``Road vehicles--Ergonomic
aspects of transport information and control systems--Occlusion
method to assess visual demand due to the use of in-vehicle
systems'' with the following exceptions:
    a. Where the ISO Standard states that at least 10 participants
are to be tested, the NHTSA Guidelines recommend that 24
participants be tested.
    b. Where the ISO Standard states that each test participant
should be given at least two and up to five practice trials for each
testable task, the NHTSA Guidelines recommend that each test
participant receive as many practice trials as needed to become
comfortable in performing the task.
    8. The viewing interval (shutter open time) should be 1.5
seconds followed by a 1.5-second occlusion interval (shutter closed
time). The sequence of viewing intervals followed by occlusion
intervals should occur automatically without interruption until the
task is completed or the trial is terminated.
    9. Task stimuli (e.g., addresses, phone numbers, etc.) are
provided to a test participant prior to the start of testing. When
the task stimuli are given to a test participant, the device should
be occluded (i.e., a test participant cannot see the device
interface) and it should remain occluded until after testing has
begun.
    11. Testing starts when a test participant informs the
experimenter that he or she is ready to begin the trial. The
experimenter then triggers the alternating sequence of viewing
intervals followed by occlusion intervals.
    12. When a test participant has completed the task, he or she
verbally instructs the experimenter that the task has been completed
with the word, ``done'' (or other standardized word). The
experimenter stops the occlusion apparatus operation.
    13. There should be an automatic means of recording the number
of unoccluded intervals a test participant needed to complete the
task.
    14. Each test participant performs each task being tested five
times to determine whether that task meets the acceptance criterion.
    15. As per ISO 16673:2007, invalid trials are removed. Note that
unoccluded total task time is not determined as part of this test
procedure. Therefore, the occluded total task time greater than four
times the average unoccluded total task time trial exclusion case in
ISO 16673:2007 cannot be used. Individual trials are considered
invalid and removed if:
     A test participant refuses to complete a trial,
     A test participant says he or she is done with a trial
but is not,
     The experimenter judges that the participant cannot
successfully complete a trial,
     The experimenter judges that the participant is not
genuinely attempting to perform the protocol and related tasks as
instructed, or
     A task performance error is made by the test
participant. The handling of task performance errors is discussed in
Subsection VI.H.
    16. As per ISO 16673:2007, the mean Total Shutter Open Time
(TSOT) for each test participant is calculated.
    17. Acceptance Criterion. A task should be locked out for
performance by drivers while driving unless the mean TSOT calculated
above is 12.0 seconds or less for at least 21 of the 24 test
participants.

H. Task Performance Errors During Testing.

    1. ``Error-Free'' Performance During Testing. During testing,
only data from ``error-free'' test trials (as defined in section
IV.B.5 and IV.B.6) performed by test participants should be used for
determining whether a task is suitable for performance while
driving.
    2. Error means that a test participant has made an incorrect
input when performing a requested task during a test trial. An error
has occurred if the test participant has to backtrack during
performance of the task or delete already entered inputs. If the
device can accommodate an incorrect entry without requiring
backtracking and extra inputs beyond those necessary to reach the
desired end state of the task, then no error is deemed to have
occurred.
    3. For driving simulator testing, when an error is made, data
from that test participant should not be used to determine task
acceptability for performance while driving. This data would be
retained for the determination as to whether a task was unreasonably
difficult. An additional test participant in the correct demographic
group should be added. Testing should continue until 24 test
participants have completed the task without errors (or until four
test participants do not meet the acceptance criteria).
    4. For occlusion testing, when an error is made, data from that
trial should not be used to compute a test participant's mean TSOT
to determine task acceptability for performance while driving. This
data would be retained for the determination as to whether a task
was unreasonably difficult. If a test participant makes errors on
two or fewer of their five trials, then their average Total Shutter
Open Time (TSOT) can still be computed and used to determine task
acceptability for performance while driving. If a test participant
makes errors on three or more of their five trials, then none of his
or her data should be used to determine task acceptability (but all
of it retained to determine whether a task was unreasonably
difficult). In this situation, an additional test participant in the
correct demographic group should be added. Testing should continue
until 24 test participants have completed the task with two or less
trials with errors (or until four test participants do not meet the
acceptance criteria).
    5. Unreasonably Difficult Tasks. A record should be kept during
testing as to whether one or more errors occurred during each test
trial. If errors occur during more than 50 percent of test trials
while testing to determine a task's acceptability for performance
while driving, then that task is deemed an ``unreasonably difficult
task'' for performance by a driver while driving. Unreasonably
difficult tasks are not recommended for performance while driving
and should be locked out.

VII. RECOMMENDATIONS FOR PASSENGER OPERATED DEVICES.

    These Guidelines primarily are applicable to human-machine
interfaces of devices intended for use by a driver. They are
applicable to a limited extent to devices intended for use by front
seat passengers.

A. Apply if Within Reach or View of Driver.

    These Guidelines are applicable to devices that can reasonably
be reached and seen by a driver who is properly restrained by a seat
belt even if they are intended for use solely by front seat
passengers.

B. Not for Rear Seat Devices.

    These Guidelines are not applicable to devices that are located
solely behind the front seat of the vehicle.

VIII. DRIVER DISTRACTION GUIDELINES INTERPRETATION LETTERS.

    NHTSA intends to clarify the meaning of its Guidelines in
response to questions that are asked through the issuance of
interpretation letters.

A. Guideline Interpretation Letter Procedure.

    1. Guidelines interpretation letters will only be issued in
response to specific written requests for interpretation of the
NHTSA Guidelines.
    2. Requests for Guidelines interpretation letters may be
submitted to the National Highway Traffic Safety Administration. The
mailing address is:

Chief Counsel
National Highway Traffic Safety Administration
1200 New Jersey Ave., SE.
Washington, DC 20590

    3. Responses will be mailed to requestors, published in the
docket, and posted in a designated area on the NHTSA Web site.

    Issued in Washington, DC, on: April 19, 2013. Under authority
delegated in 49 CFR 1.95.
David L. Strickland,
Administrator.
[FR Doc. 2013-09883 Filed 4-23-13; 4:15 pm]
BILLING CODE 4910-59-P