Delphi questioned whether NHTSA's effectiveness numbers were
accurate. The company stated that NHTSA's analysis of sensor
effectiveness, which showed that sensor systems had a 39 percent
detection rate and that a combination sensor/video system had a 15
percent driver performance result, should be used carefully because the
sensors were not designed to detect children. Instead, Delphi stated
that current OEM sensor systems are designed to the ISO 17386
standard,\54\ which asserts performance requirements for object
detection devices that provide information to the driver regarding the
distance to an obstacle during low-speed operation. This ISO standard
specifies a PVC cylinder for use in measuring systems' detection
performance, and does not require the detection of objects low to the
ground so that systems are permitted to avoid detecting curbs.
---------------------------------------------------------------------------

    \54\ ISO 17386:2004 Transport information and control systems--
Manoeuvring Aids for Low Speed Operation (MALSO)--Performance
requirements and test procedures. This standard applies to object
detection devices that provide information to the driver regarding
the distance to an obstacle during low-speed operation.
---------------------------------------------------------------------------

    Delphi also provided extensive comments regarding sensor-based
systems in terms of their abilities and how they may best be used. It
suggested that sensors are an important addition to rearview video
systems, as drivers need prompting in order to glance at the screen
when an obstruction appears. The company also suggested that a sensor
system with varying warnings, dependent on the calculated time-to-
collision, could provide drivers with additional information that could
be used to prevent backover crashes. Delphi stated that radar sensors
are more efficient at detecting children than ultrasonic sensors, and
can detect targets at greater ranges. With regard to test targets for
sensor systems, it commented that any test target should be chosen to
provide a minimum reflectivity that is representative of the smallest
required detectable object (e.g., 1-year-old child).
    Ackton was another company that noted that current sensors are
designed to the ISO 17386 standard, and are not designed to detect
children. It stated that until there is a pedestrian-detection
standard, many systems will not be designed to pass it, and will
therefore fail to detect pedestrians. Sony also stated that current
sensors are designed as parking aids and are optimized to detect hard
surface objects, but that technical advances may improve the ability of
such systems to detect non-occupant pedestrians.
    Ackton also commented that its ``New-Gen'' ultrasonic technology
can detect a 36-inch child at a distance of 15 feet. Along similar
lines, Magna commented on two future technologies discussed in the
ANPRM, infrared and video-based object recognition systems. Magna
stated that these systems were in active development, and would be
ready for production by 2011.
    Continental commented that in the future advanced systems may be
developed that respond automatically with automatic braking to avoid a
backing crash without any action from the driver. It stated that in the
future, systems will be able to recognize pedestrians that are in
danger of being struck and automatically intervene to prevent that from
happening. Continental gave no indication of the timeframe for
availability of such technology.
    IIHS stated that the combination of sensors' unreliability and
drivers' slow and inconsistent reactions to audible warnings suggest
that requiring, or even allowing, sensors in lieu of a visual backover
countermeasure systems is not advisable at this time, although sensors
could augment other technologies. Kids and Cars and Magna also pointed
to the audible signals from sensors as a source of annoyance to many
drivers, especially given the prevalence of false positives, which
caused many drivers to ``tune out'' the warnings. However, Magna stated
that if the sensor warnings were provided visually (such as on a
graphical overlay), drivers would be less prone to be irritated by them
and therefore less likely to ignore them.
    Advocates for Highway and Auto Safety suggested for sensor-based
systems that the agency consider an interlock requirement that
prohibits the vehicle from being able to be moved in reverse, even
after the transmission has been placed in reverse gear, until a short
period after the system becomes fully operational.
vi. Use and Efficacy of Rearview Video Systems
    In the ANPRM, NHTSA presented its research on rearview video
systems. Commenters discussed these systems at length. In summarizing
these comments, we have divided them into two general groups. The first
section describes the comments relating to the general effectiveness of
rearview video systems in aiding drivers to avoid backing crashes. The
subsequent section summarizes the comments relating to the specific
possible requirements for rearview video systems, such as camera
performance, visual display characteristics, etc.
    Many commenters, including manufacturers of video cameras, safety
organizations, and individual commenters, stated that rearview video
systems would be the best system to prevent backover crashes.
Commenters supporting this proposition included Consumers Union, Kids
and Cars, IIHS, Magna, Nissan, and Sony.
    Consumers Union also supported the application of rearview video
systems, noting their potential to save lives, and also asserted that
their efficacy would improve as users grew more accustomed to using
them in their everyday driving.

It added that it believed a rearview video system coupled with a sensor
system would be the overall best system. While Consumers Union referred
to NHTSA's research study as involving drivers ``trained'' to use
rearview video systems and the other systems tested, the agency notes
that all drivers who participated in the study had owned and driven the
system-equipped vehicle and had driven it as their primary vehicle for
at least 6 months prior to study participation, but did not receive any
specific training in the use of a rearview video system.
    Advocates for Highway and Auto Safety pointed out that a video
image of the area behind a vehicle immediately conveys information
about rear obstacles and pedestrians within the system's field of view
without any need for interpretation by the driver. This quality was
noted as an advantage of rearview video systems over rear-mounted
convex mirrors and sensor-based systems.
    Magna stated that it believes camera technology has the potential
to significantly enhance safety and that a rearview video system ranks
highest by far, in regard to system performance and overall
effectiveness estimates. In its responses to specific questions, Magna
provided some additional research showing the overall effectiveness of
rearview video systems in preventing backover crashes, which is
discussed in Section F below.
    Sony stated that it agrees with the majority of analysis provided
and the preliminary conclusions reached observations made in the ANPRM.
Specifically, Sony recommended that any amendment to FMVSS No. 111
should require backover prevention technologies to detect obstacles in
areas other than immediately behind the vehicle. Sony stated that
rearview video systems with 180-degree video cameras would be best able
to address real-world backover crash scenarios, in which a majority of
pedestrians enter the vehicle's path from the side.
    Nissan provided some comments on its ``Around View Monitor'', which
provides a birds-eye (i.e., overhead) view of the area around the
vehicle on all four sides. The company stated that their system was
designed primarily as a parking aid, and that it will have significant
limitations if used to protect children. Nissan stated that rearview
video technology in general is a useful parking aid, but that its
utility in preventing backover crashes may be limited, because drivers
must be looking at the screen in order to see a pedestrian incur into
their path. Nissan drew attention to the glance behavior cited in
NHTSA's research, noting that on average drivers looked at the visual
display twice, or about 8-12 percent of the time. It stated that this
may not be enough to detect the pedestrian in time to react, even if
the driver is using the rearview video system correctly, and that
driver glance behavior has a significant effect on rearview video
system effectiveness. Nissan also cautioned against excessive reliance
on a video-based backing aid, cautioning that if a driver is relying
excessively upon rearview enhancement technology, the operator can miss
seeing a person or an object positioned just outside of that field of
view. Nissan also stated that it is imperative that the operator always
confirm clearance of the entire path of travel, and turn around and
look during a backup maneuver.
    The AAM made several comments similar to those of Nissan, stating
that no safety countermeasure or safety technology is completely
effective. AAM stated that regardless of the technology adopted to
expand a driver's field of view, the driver is ultimately responsible
for the safe operation of the vehicle. AAM characterized rear
visibility enhancement systems as supplemental drivers with
responsibility resting on drivers to use them properly.
    GM stated that its analysis showed some limited benefits may be
provided by rearview video technologies, but that potential solutions
will continue to be limited by driver behavior. GM stated that it
agrees with NHTSA that drivers' expectations influence behavior and
system effectiveness, and that further improvements in the
effectiveness of rearview video technologies may be achieved by
improving feedback to the driver and improving driver behavior through
education.
vii. Characteristics of Rearview Video Systems
    NHTSA received numerous comments relating to the specific
characteristics of rearview video systems. These related to issues of
camera placement, durability, and performance, as well as visual
display characteristics, such as location (i.e., in the dashboard, or
in the rearview mirror), brightness, and the functionality of the
backing image. Commenters presented extensive comments on issues such
as visual display size, whether digital graphical overlays should be
used, and other characteristics related to these systems. IIHS noted
that there was a wide range of performance by various current rearview
video systems it examined and, based on this; expect that NHTSA will
need to specify performance requirements to ensure a minimum level of
performance for those systems.
    Several commenters, including Consumers Union and Magna,
recommended that NHTSA consider inclusion of graphic overlays as part
of a video-based backover countermeasure, stating that this increases a
driver's ability to detect obstacles, and makes the driver more likely
to use the system.
    NHTSA also requested comment regarding characteristics such as
video camera angle, durability, and low-light performance, as well as
contrast, image response and linger time, and display size and
location. Commenters provided a wide array of suggestions.
    IIHS stated that some rearview video systems are much more immune
to weather and road dirt contamination than others, and recommended
that NHTSA specify performance requirements to ensure that systems can
withstand adverse conditions.
    Sony offered an observation that while adverse weather conditions
can affect rearview video system performance, cameras utilized in such
applications are sealed in watertight housings and mounted at a
downward angle, and therefore generally protected from the elements.
Sony also commented on the number of backover incidents in which
victims were struck after approaching from the side of the vehicle,
stating that the incidence rate was 45 percent. It stated that this
indicated that wide-angle rearview video systems would best prevent
backover incidents.
    Magna, on the other hand, commented that in order to assure overall
system affordability across the widest possible range of vehicle types
and models, NHTSA should not impose specific operational requirements
on rearview video systems. It noted that ``anti-wetting'' and ``anti-
soiling'' techniques are known and currently implemented despite the
lack of a legislative mandate.
    In its comments, Gentex stated that the interior rearview mirror is
an ideal location for the rearview video system visual display. Gentex
stated that that location is intuitive, logical, and ergonomic, and
allows the driver to maintain a ``head-up'' position while viewing the
display and the rearview mirror simultaneously. Furthermore, it noted
that drivers are already trained to look in the interior rearview
mirror when reversing. Magna also commented that the interior mirror is
the best location for a rearview video system visual display, noting
that the display in that location is much closer to the driver's eyes.
However, Magna suggested that NHTSA not prescribe

specific requirements regarding display location, image size, or other
requirements, as doing so may result in unintended restrictions on
technology applications.
    With regard to image size, commenters submitted a number of ideas
for what a minimum visual display size should be. Gentex stated that it
disagreed with NHTSA's suggestion that a minimum 3.25 inch screen size
might be specified. Instead, they suggested a minimum viewable display
height of 1.3 inches, based on its calculation of what the human visual
system can generally resolve and the mean distance between the driver's
eyes and the visual display. Ford also commented on NHTSA's minimum
visual display size suggestion, stating that the GM research cited by
NHTSA was not designed to assess system effectiveness as a function of
visual display size since it only used one in-mirror display size, and
in fact concluded that rear effectiveness was not affected by image
size in the scenario used. Instead, Ford suggested that GM used a 3.5
inch screen in its study because it was offered as a regular production
option, and that NHTSA's reliance on GM's research was inappropriate.
    In lieu of the 3.5 inch minimum visual display size, Ford suggested
that an Australian regulation on screen sizes for rear visibility
systems (specifically, New South Wales' Technical Specification No.
149), could be used as a model. According to Ford's comment, this
regulation states that when a 600 mm test cylinder is located five
meters from the rear of the vehicle, the height on the screen should be
no less than 0.5 percent of the distance between the driver's eye and
the visual display. The company claimed that this technique has
resulted in several iterations of a 2.4 inch screen size and that they
have been readily accepted by consumers.
    Magna, on the other hand, referred to studies by GM and the
Virginia Tech Transportation Institute indicating that a 3.5 inch
visual display, mounted in the interior rearview mirror, led to the
highest crash avoidance rates.
    Certain commenters focused on some of the other specifications of
the visual display. Image response time, or the delay between when a
vehicle is shifted into reverse and the rearview image from the video
camera appears, was discussed extensively by Gentex. While NHTSA had
suggested a maximum of 1.25 seconds for this value, Gentex recommended
3 seconds, based on its calculations of the time needed for signal
transfer, powering the camera, and the complexity of the electronics.
GM supported Gentex's comments on this matter.
    Gentex made two additional recommendations with regard to visual
displays in its comments. The company suggested a minimum brightness of
500 candelas per square meter (cd/m\2\) for the screen, as well as a
minimum contrast ratio of 10:1.
    Consumers Union made a number of suggestions regarding displays for
rearview video systems, including that there needs to be a minimum
display size and that a maximum image response time of 1 second, and a
maximum linger time between 4 and 8 seconds should be required. GM
recommended a maximum linger time of 10 seconds or, as an alternative,
a speed-based limit in which the rearview video display would turn off
when the vehicle reach a speed of 5 mph (8 kph). Based on their
observations of drivers making parking maneuvers, the AAM also
recommended a maximum linger time of 10 seconds, but specified an
alternative speed-based value of 20 kph (12.4 mph).
    Ms. Susan Auriemma, of Kids and Cars, offered a personal testimony,
stating that as a user of a rearview video system with an image
response time of 2-3 seconds, there is a tendency to want to proceed to
back the vehicle without waiting for the image to appear.
viii. Development of a Performance-Based or Technology-Neutral Standard
    Numerous commenters suggested that any NHTSA standard be
performance-based and technology-neutral. These commenters generally
supported the idea that the blind zone must be limited to a certain
size, or that certain areas behind the vehicle should be visible, but
did not want NHTSA to prescribe how these areas should be detected.
Instead, these commenters stated that allowing the manufacturer to
determine the means by which the required area is detectable would
promote styling flexibility, technological innovation, and help to
contain costs.
    MEMA stated that it supported a performance-based test, stating
that ``it is clear that there is no one solution to mitigating backover
events.'' It also suggested that various countermeasures can be
incorporated, whether complementary or separately, to promote increases
in the rear field of view.
    Delphi stated that there would be no reason to not grant compliance
credits to vehicle manufacturers who choose any system, mirrors,
sensors, or video, which detects the required areas behind a vehicle.
    AIAM, in its comments, pointed out specific problems with all three
countermeasure technologies, and then suggested that some of the issues
would present a greater challenge for certain classes of vehicles. In
light of that, it suggested that performance-based requirements would
allow vehicle manufacturers to achieve the best match of technical
approach for each of their vehicle models.
    AORC stated that it believes that the regulation should allow for
the enhancement of rear visibility via the implementation of rearview
video systems or the use of sensor input. It stated that these systems
should be subject to a pure performance requirement, and must able to
detect children from a distance of 0.25-3.00 meters behind the vehicle.
    Kids and Cars urged the agency to not only set the highest feasible
rear visibility standard, but to also allow new innovative product
designs that will evolve as technology matures.
ix. Other Issues Addressed in Comments
    This section summarizes comments related to ancillary issues
regarding rear visibility. For example, several commenters suggested
that NHTSA design a performance rating system for rear visibility,
issuing it in addition to, or in lieu of, a countermeasure performance
requirement. Alternatively, suggestions for driver education proposals
were made. Some commenters also discussed the rate at which any rear
visibility standard be phased in.
    Several commenters suggested that a performance rating system be
developed, to provide consumers information about the rearward
visibility characteristics of various vehicles. Delphi stated that a
performance rating system would have the effect of giving consumers the
necessary facts to purchase vehicles that offer the best choice of
safety and value, and would encourage continued innovation in backover
avoidance technology.
    AORC suggested a performance rating system for rear visibility
enhancement systems, similar to ones used in NHTSA's New Car Assessment
Program, as it could give consumers information relating to vehicle
purchase. This idea was also supported by Magna, which recommended a
five-star Federal safety rating program.
    The AAM recommended that NHTSA provide information to consumers
about proper backing procedures, as well as the capabilities and
limitations of rear visibility countermeasures.

    Another remark by Kids and Cars member, Ms. Susan Auriemma, focused
on ``proper backing procedures.'' Specifically, the commenter stated
that research is needed to define what proper use of a rearview video
system is in terms of how often a driver should look at a rearview
image, and whether a driver should also look directly behind the
vehicle and at the mirrors. Ms. Auriemma also questioned whether the
sample size used by NHTSA, 37 drivers, was large enough to make
definitive conclusions regarding backing behavior and rearview video
system use.
    Several commenters requested that the phase-in period for rear
visibility system requirements be extended beyond the four-year period
mandated in the K.T. Safety Act. Honda stated that in addition to the
cost of the systems, there could be considerable costs if major design
changes are required before vehicles are scheduled for normal redesign.
The company suggested that the costs could be substantially reduced if
only one or two additional years are allowed for the phase-in schedule
to coincide with existing redesign plans. AIAM also suggested a six-
year phase-in schedule so that changes could be implemented in
accordance with vehicle redesign schedules. It also stated that small
volume and limited line manufacturers should be excluded from the
visibility requirements until the end of the phase-in period is
reached, due to reduced access to technologies and generally longer
product life cycles compared to larger manufacturers.
    One comment from Sony suggested that a mechanism to reduce costs
would be to eliminate the U.S. import tariff on rearview video camera
imports, which currently stand at 2.1 percent. Kids and Cars suggested
that NHTSA also consider proposing a ``forward visibility'' standard to
prevent ``frontovers,'' stating that fatalities from such accidents
have increased substantially in recent years.
    Finally, NHTSA received several comments from individuals relating
personal experiences involving backover crashes. One anonymous
commenter, who had backed over their son, recommended that backup
sensors and/or rearview video systems be put in all vehicles. Ms.
Shannon Campbell described a personal backover experience with a
``sport utility vehicle'' (SUV), and stated that it is impossible for
the driver to see behind the vehicle without a rearview video system.
Similarly, Mr. Donald Hampton, whose granddaughter was involved in a
backover with an SUV, recommended that every new vehicle have a
rearview video system, stating that an add-on video camera kit costs
around $100. Ms. Sharron DiMario, who son was involved in a backover
with a minivan, recommended safety modifications to dramatically
improve vehicle blind spots. Ms. Karena Caputo, who son was involved in
a backover with a Hummer, stated that children cannot be seen behind
vehicles, and that every vehicle should have some type of backup safety
device. Ms. Andriann Raschdorf-Nelson, whose 16-month old son was
involved in a backover with an SUV, simply applauded NHTSA's decision
to make all vehicles safer for children. Ms. AnnMarie Bartlett-
Pszybylski commented that she had installed a rearview video system on
her vehicle after a backover incident involving her son. Mr. David
Sarota requested that NHTSA promulgate a Federal regulation after
witnessing a near-backover involving a small truck. Finally, Mr. Paul
Faragher Anthony whose 23-month-old son was the victim of a near-fatal
backover incident involving a van equipped with a rear-mounted convex
mirror, which he stated ``do nothing to improve the field of view
downward, where a toddler is likely to be.''
    Kids and Cars discussed the specifics of backover crashes. It
stated that parents and relatives have a greater vulnerability to
backover crashes because they are involved in more backing situations
when young children are present. Kids and Cars stated that in all the
backover cases they documented, the parent or relative driving the
vehicle was unaware the child was behind the vehicle.
x. Suggested Alternative Proposals
    In their comments, several commenters laid out suggested proposals
for addressing the problem of backover crashes. Suggestions were
received from GM, AORC, Mr. Louis Martinez, and the AAM. We have
summarized these alternative proposals below.
    GM suggested a two-part alternative proposal. First, GM suggested
that NHTSA expand the required field of view to the sides and rear of
the vehicle, through establishing passenger side mirror requirements
and expanding the existing driver side requirements. Second, GM
suggested that all vehicles meet a maximum blind zone requirement,
using an alternative ``indirect'' measurement of rear visibility. GM
proposed an indirect threshold limit of 100 to 125 square feet, which
it indicated would correspond to a direct-view blind zone area of
approximately 400-500 square feet using the methods described by NHTSA
in the ANPRM. Vehicles that did not meet this threshold indirect
visibility requirement would need additional rear vision enhancements,
such as video cameras, to meet the requirements.
    The AAM suggested a three-part alternative proposal in its
comments. First, it suggested that NHTSA adopt European mirror
requirements (ECE R46) for both driver and passenger side convex
mirrors, for reasons described above. Second, it suggested NHTSA
develop performance-based criteria to identify vehicles that may
require additional countermeasures. Third, it recommended that NHTSA
increase consumer information about capabilities and available
technology intended to enhance rear detection capability and enhance
driver education.
    AORC suggested dividing the area behind the vehicle into a
``warning zone,'' extending three meters behind a vehicle, and an
``observation zone,'' extending an indefinite distance behind the
warning zone. Video cameras and sensors would be required to perform
different warning and obstacle-avoidance tasks for objects within the
two zones, and would be tested using a 0.75 meter (2.5 ft) tall object
with human form approximation.
    Mr. Louis Martinez submitted a description of a ``three-piece
interior rear view mirror assembly for vehicles.'' According to the
commenter, this planar mirror assembly would enable driver to view more
areas to the sides and rear of the vehicle without having to turn his
or her head or adjust the mirrors.
xi. Costs and Benefits
    Commenters also provided information which they stated could be
used to develop the costs and benefits of the agency's rear visibility
proposal.
    Consumers Union stated that it believes the cost of rearview video
systems, cited in the ANPRM, were too high, as they related to stand
alone options. They suggested that the true cost to the OEM is less
than $100. Consumers Union did not cite a source for this figure.
    The Advocates for Highway and Auto Safety stated that the safety
benefits noted in the ANPRM are in accord with project benefits for
other NHTSA safety rules, such as the agency's recent upgrade of the
roof crush resistance standard. The Advocates also posited that the
benefits eventual savings in backover incidents may actually prove to
be more effective than the roof crush rule.
    Magna stated that it believed the costs of rearview video systems,
as cited by NHTSA, were on the high end of the spectrum. It added that
as the number of automotive video cameras increases,

their price will decline. Magna did not provide any indication of how
low the price may get.
    Ms. Susan Auriemma of Kids and Cars said that NHTSA should not be
limited by monetary considerations in determining standards that may
save children, stating that the value of the life of a child should not
be equal to that of a 70-year old adult.

F. Questions Posed and Summary Response

    NHTSA asked a series of 43 questions in the ANPRM on a wide variety
of topics. In this section, we have reprinted the questions and grouped
the significant responses by topic. Because of some of the information
we received and further research we undertook subsequent to the ANPRM
publication, some of the questions we asked no longer have significant
bearing on the proposal (such as questions about methodologies for
measuring blind zone size), but we have summarized the responses for
the sake of completeness. Because several commenters separated their
general comments from their specific responses to NHTSA's inquiries, we
have summarized those responses separately. Note that this section
contains only responses from those commenters who elected to explicitly
respond to each or a subset of questions. Comments that related to
questions asked, but were included in the body of the text, are
addressed above.
i. Technologies for Improving Rear Visibility
    The first series of questions was related to issues regarding the
three main technological solutions--mirrors, sensors, and rearview
video systems. NHTSA was interested in collecting information on the
effectiveness, characteristics, and implementation of these
technologies.
    Question 1: While the objective to ``expand the required field of
view to enable the driver of a motor vehicle to detect areas behind''
the vehicle implies enhancement of what a driver can visually see
behind a vehicle, the language of the K.T. Safety Act also mentions
that the ``standard may be met by the provision of additional mirror,
sensors, cameras, or other technology.'' NHTSA seeks comment with
regard to the ability of object detection sensor technology to improve
visibility and thereby comply with the requirements of the Act.
    Responses: The commenters generally did not address the question of
whether object detection sensor technology was literally capable of
expanding the driver's view of the area immediately behind his or her
vehicle, as opposed to increasing the driver's awareness of objects
within that area.\55\ They focused instead on the performance of that
technology.
---------------------------------------------------------------------------

    \55\ As noted near the beginning of this document, the inclusion
of sensors in this sentence as a ``technology to expand the driver's
field of view'' suggests that ``expand the required field of view''
should not be read in the literal or natural way as meaning the
driver must be able to see more of the area behind the vehicle. A
literal or natural reading would make the reference to sensors
superfluous, violating a basic canon of statutory interpretation.
Instead, it seems that language could be read as meaning the driver
must be able to monitor, visually or otherwise, an expanded area.
---------------------------------------------------------------------------

    NHTSA received mixed views about its performance, with industry
groups, GM, and equipment manufacturers including Ackton, Continental,
Delphi, and Magna requesting that the agency make any requirements as
technology-neutral as possible, so as to allow innovation and
technological improvements, while others agreed with NHTSA's tentative
thinking in the ANPRM that sensor technology may not function
effectively in preventing backover crashes.
    GM and Delphi said any technology is better than none, while Sony
and Consumers Union recommended that rearview video may provide a
better margin of safety with regard to backover crashes. GM and the AAM
responded by saying that any technology that can provide a view of the
rear of the vehicle should be permitted to comply with a rear
visibility requirement. AAM added that given drivers' tendency to rely
on mirrors once the backing maneuver starts, requirements should not
preclude any technology.
    Specifically in regard to sensor-based systems, Ackton stated that
their product uses ``New-Gen'' ultrasonic technology that can detect
another vehicle at a range of up to 30 feet and can detect a 36-inch-
tall child at a range of up to 15 feet. On the other hand, Consumers
Union and Nissan stated that they agreed with NHTSA's findings that
sensor-based systems are inconsistent and unreliable in detection
pedestrians, particularly small children, behind a vehicle. Nissan also
commented that it generally agrees with NHTSA's evaluation of sensor-
based systems and believes that they are generally unreliable in
detecting pedestrians, particularly children. Nissan also stated that
sensor-based ``systems may not be able to detect children or detect
them in time for the driver to react.'' Magna stated that it concurred
with NHTSA's finding that sensor-based systems are inconsistent and
unreliable in detecting children.
    Ms. Susan Auriemma stated that false alarms occur frequently with
sensors, and that they would be unhelpful in situations where the
vehicle was near known obstructions, such as in garages, therefore
recommending that sensors not be permitted to meet the requirement.
Furthermore, she added that a malfunctioning sensor system could impart
a false sense of security to a driver, who hearing no warning, might
assume the path is clear.
    Question 2: What specific customer feedback have OEMs received
regarding vehicle equipped with rear parking sensor systems? Have any
component reliability or maintenance issues arisen? Is sensor
performance affected by any aspect of ambient weather conditions?
    Responses: GM responded to this question by stating that the
parking sensor systems have been generally reliable. AAM stated that
weather, dirt, snow, harsh sunlight, intense cold, or high levels of
ambient noise can reduce sensor performance. Mercedes also responded to
this question, but with information it wished to keep confidential.
Kids and Cars stated that it believes that people tend to ``tune out''
the sound of a sensor as they back out of a garage, as it can register
a false positive from the garage walls, which would lessen its
efficiency in preventing backover crashes.
    Question 3: What specific customer feedback have OEMs received
regarding vehicles equipped with rearview video systems? Have any
rearview video system component or reliability issues arisen?
    Responses: NHTSA received several responses to this question,
indicating that most rearview video systems demonstrated good
reliability. Other commenters pointed out that the systems have not
been installed on vehicles for significant periods of time, so the data
regarding their reliability are limited. GM stated that they have
generally received favorable customer feedback regarding the
performance and operation of their rearview video systems, but have had
some negative comments regarding the camera lens needing to be
periodically cleaned to remove contaminants. Magna stated that
consumers gave positive feedback to the following features in rearview
video systems: A wide-angle field of view, electronic image distortion
reduction, graphical overlays, and interior mirror screen locations.
Furthermore, Magna commented that it was not aware of component
reliability problems in excess of what is normally seen in automotive
systems. Rosco added that audio-enhanced video systems were positively
received by customers. Sony

stated that video camera design for vehicles focuses on reliability,
with particular attention to water resistance, vibration
susceptibility, EMI sensitivity, and scratch resistance, and stated
that the number of warranty returns for its video cameras were low.
    Kids and Cars commented that 85 percent of individuals with these
systems felt the systems were effective or very effective, and Ms.
Auriemma noted a personal experience where a rearview video system had
functioned for several years without malfunctioning.
    Question 4: What are the performance and usability characteristics
of rearview video systems and rear-mounted convex mirrors in low light
(e.g., nighttime) conditions?
    Responses: In general, commenters including Nissan, GM, and Sony,
seemed confident that, combined with backup lamps (required by FMVSS
No. 108), rearview video systems and mirrors would provide a
sufficiently visible image in low light conditions. Ms. Auriemma
commented that her rearview video system works well under low light
conditions. One commenter did point out that sensors, unlike those
other systems, would not be affected by low ambient light conditions.
Magna stated that performance depends, in part, on the luminous
intensity of the tail lamps and backup lamps, but that low-light
performance of current systems does improve rear visibility. Rosco
stated that to improve nighttime performance, it incorporates infrared
and audio technology into its rearview video systems.
    Regarding specific performance information, GM stated that its
rearview video system provide an image in 3 lux lighting conditions.
While Sony indicated that their current video cameras operate in
conditions as low as 1 lux, they recommended 5 lux with reverse gear
and lamps engaged as an appropriate minimum light level for rearview
video system compliance testing.
    Question 5: Is there data available regarding consumers' and
vehicle manufacturers' research regarding backing speed limitation,
haptic feedback to the driver, or use of automatic braking?
    Responses: Commenters, such as GM, indicated that these systems
have not been applied to backing conditions. However, Magna indicated
that some technologies have been applied in certain vehicles, and that
haptic feedback alerts can be effective in capturing the driver's
attention. The Alliance added that a review of the SCI cases indicates
that excessive backing speed was not a primary risk factor in backover
incidents, but Nissan stated that research is being conducted, and that
it expects that performance of backover countermeasures will improve
when used in combination with a reduction in backing speeds.
    Question 6: What types of rear visibility countermeasures are
anticipated to be implemented in the vehicle fleet through the 2012
timeframe?
    Responses: Without giving specific numbers, commenters did indicate
that they expect rearview video systems to be installed on an
increasing percentage of their fleets. The AAM stated that the same
technologies employed today will likely be used in 2012. Nissan stated
that it will continue to offer as parking systems a rearview video
system, as well as its Around View Monitor system. Honda commented that
rearview video systems are currently on Honda and Acura SUVs, as well
as the Ridgeline pickup, Odyssey minivan, and several sedans and
coupes. Magna stated that it forecast around 500,000-750,000 vehicles
produced in North America will be equipped with a rearview video
system, and Rosco added that the evolution of technology has been
moving towards rearview video systems.
    Continental stated that in the future, systems will be able to
recognize pedestrians that are in danger of being struck and
automatically intervene to prevent that from happening. However, they
gave no indication of the timeframe for availability of such
technology.
    Takata provided confidential comments on anticipated developments
in rear detection technology, including the estimated detection
capabilities of future products.
    Question 7: Can rear-mounted convex mirrors be installed on light
vehicles other than SUVs and vans? What is the rationale for U.S.
manufacturers' choosing to install rear parking sensors and video
cameras, rather than rear-mounted convex mirrors as are commonly
installed on SUVs and minivans in Korea and Japan? NHTSA is
particularly interested in any information on the effectiveness of
rear-mounted convex mirrors in Korea and Japan.
    Responses: NHTSA received a number of responses to this question.
AAM, GM, and other stated that rear-mounted convex mirrors cannot
feasibly be mounted on passenger cars with a sloping rear window
surface. The commenters stated that these sorts of mirrors are
generally considered unattractive and are not well-received by
consumers. Kids and Cars also speculated that consumers may find them
unappealing, or that they may strike people or objects in tight areas.
    Honda provided information that these mirrors, widely used in Asia,
are being phased out in favor of rearview video systems. Furthermore,
it noted that these mirrors are used as parking aids, and would not be
effective for obstacle avoidance in non-parking backing maneuvers. GM
indicated that their research has shown that rear-mounted convex
mirrors do not demonstrate any effectiveness in reducing backover
crashes in the situations they examined. Rosco stated that it provides
these mirrors to customers such as the United States Postal Service and
other commercial package delivery services.
    Question 8: NHTSA seeks any available research data documenting the
effectiveness of rear convex cross-view mirrors in specifically
addressing backover crashes.
    Responses: GM and the Alliance stated that they were not aware of
research on this topic.
    Question 9: NHTSA seeks comment and data on whether it is possible
to provide an expanded field of view behind the vehicle using only
rear-mounted convex mirrors.
    Responses: Honda and GM both responded that the utility of rear-
mounted convex mirrors was limited in this regard. Honda stated that
this was due to ``minification'' (the small image size) and distortion
problems. The AAM pointed to its responses to questions I-7, II-5, and
III-10 as being relevant to this question.
    Question 10: NHTSA is aware of research conducted by GM that
suggests that drivers respond more appropriately to visual image-based
confirmation of object presence than to non-visual image based visual
or auditory warnings. Is there additional research on this topic?
    Responses: GM responded to this question, and reiterated the
results of its research, stating that while all people that saw the
rear obstacle applied the brakes, most people who simply heard a
warning looked for the object first, and did not stop if they did not
get visual confirmation. Magna stated drivers have a higher tolerance
for visual alerts than for auditory alerts, which drivers view to be
intrusive (and hence, can get tuned out). Magna said that visual
overlays are best tolerated by drivers, even when they discern that the
object being highlighted is benign. The Alliance pointed to its answer
to question I-1 as applying to this question.
    Question 11: NHTSA requests input and data on whether the provision
of

graphical image-based displays (e.g., such as a simplified animation
depicting rear obstacles), rather than true-color, photographic visual
displays would elicit a similarly favorable crash avoidance response
from the driver.
    Responses: In response to the questions regarding whether graphical
image-based visual displays may be as effective as photographic video
displays, GM reiterated its response to question VI-2 (below).
    Sony commented that graphical image-based displays offer inferior
protection from backover crashes when compared to true-color,
photographic visual images from a rearview video system. They indicated
that rearview video images provide a wider and deeper viewable area.
Sony also stated that a graphical image-based display would require the
driver to exit the vehicle to confirm the presence of a rear obstacle,
and that if false alarm rates were high, the driver might choose to
ignore the warning and not check for an obstacle.
    Magna responded by emphasizing the benefits of graphical overlays
superimposed on a rearview video image and urged NHTSA to consider
inclusion of graphic overlays as part of a video camera-based rear
backup aid. Magna indicated that they view graphical image-based
displays as a supplement to a true color photographic visual image
rather than a substitute for such an image.
    However, the Alliance responded by stating that these technologies
are in their infancy, and requesting that regulations be crafted in
such a way as to not impede their development.
    Question 12: To date, rearview video systems examined by NHTSA have
displayed to the driver a rear-looking perspective of the area behind
the vehicle. Recently introduced systems which provide the driver with
a near 360-degree view of the area around the entire vehicle do so
using a ``birds-eye'' perspective using images from four video cameras
around the vehicle. During backing, it appears that, by default, this
birds-eye view image is presented simultaneously along with the
traditional rear-facing video camera image. NHTSA requests data or
input on whether this presentation method is likely to elicit a
response from the driver that is at least as favorable as that attained
using traditional, rear-view image perspective, or whether this
presentation is more confusing for drivers.
    Responses: Nissan, which uses this technology in some of its
vehicles, stated that it has not received negative customer feedback
about it. The AAM again stated that such systems have only recently
been introduced into the marketplace.
ii. Drivers' Use and Associated Effectiveness of Available Technologies
To Mitigate Backover Crashes
    These questions were posed in order to help NHTSA gain a better
understanding of how technologies were being deployed and used by
drivers, and to fill in gaps in research. The agency was particularly
interested in any market or research studies indicating customer
satisfaction and adoption of specific technologies.
    Question 1: NHTSA has not conducted research to estimate a drivers'
ability to avoid crashes with a backing crash countermeasure system
based only on sensor technology. We request any available data
documenting the effectiveness of backing crash countermeasure systems
based only on sensor technology in aiding drivers in mitigating backing
crashes.
    Responses: AAM commented by stating that these devices have only
been recently introduced into the marketplace, and that more time would
be needed before results would be detectable. GM's comment referred to
the results of the McLaughlin and Llaneras studies, which provided some
evidence that although warnings influenced driver behavior, warnings
were unreliable in terms of their ability to induce drivers to
immediately brake to a complete stop. GM stated that their research has
shown no additional benefit of integrated (rearview video and sensor)
systems over simple rearview video alone. Kids and Cars stated that
there is a common reaction for drivers to ``tune out'' the sensor, such
as in situations where a driver is backing out of a garage.
    Question 2: NHTSA has not conducted research to estimate drivers'
ability to avoid crashes with a backing crash countermeasure system
based on multiple, integrated technologies (e.g., rear parking sensors
and rearview video functions in one integrated system). We request any
available objective data documenting the effectiveness of multi-
technology backing crash countermeasure systems in mitigating backing
crashes. We also request comment on what types of technology
combinations industry may consider feasible for use in improving rear
visibility.
    Responses: NHTSA received a variety of responses on this issue.
While AAM indicated that the technology is too new to have good
effectiveness data, both GM and Nissan stated that multi-technology
systems were less effective than video alone. Kids and Cars, on the
other hand, commented that graphic overlays based on sensor data could
improve the user experience with rearview video systems. It also stated
that a sensor can alert a driver to a problem, and that a rearview
video system can verify that there is an obstacle behind the vehicle.
Magna stated that graphic overlays, which include fusion of ranging
sensing (i.e., using infrared or radar technology), already exist, and
can enhance the driver's ability to judge distance/depth and to
assimilate what is being displayed on the video screen.
    Question 3: NHTSA requests any available data documenting the image
quality of rear-mounted convex mirrors and their effectiveness in
aiding drivers in preventing backing crashes.
    Responses: GM responded by stating that its research indicated
rear-mounted convex mirrors offered no improvement in the prevention of
backover crashes. The AAM stated that it does not have data documenting
their performance in preventing backover crashes.
    Question 4: NHTSA requests any available additional objective
research data documenting the effectiveness of sensor-based, rearview
video, mirror, or combination systems that may aid in mitigating
backover incidents.
    Responses: Magna pointed to a variety of research studies being
performed by the Virginia Tech Transportation Institute and other
entities. Some conclusions it summarizes include: That good image
quality is important for customer acceptance; that a 3.5 inch in-mirror
display led to the highest backover avoidance rates; and that in-mirror
displays were preferred by a large majority of drivers. The AAM stated
that it does not have any data on these systems, and given the
uncertainty associated with them, recommends that NHTSA adopt a
technology-neutral regulation. GM reiterated that it had already shared
its relevant findings.
    Question 5: NHTSA requests information regarding mounting
limitations for rear-mounted convex mirrors.
    Responses: Commenters stated that they are aware of no reasonable
method for attaching effective rear-mounted mirrors to vehicles like
sedans, where such mirrors could not be mounted on or near the roof and
provide an image of the area directly behind the vehicle. The AAM
cautioned that long bracket arms would be impractical and have a
negative effect on component reliability. GM also reiterated that it
had not found the mirrors effective even when mountable. Honda added
that it believes it is impractical to apply a rear-mounted

convex mirror to vehicles with trunk lids.
iii. Approaches for Improving Vehicles' Rear Visibility
    In this section, NHTSA was presenting the regulatory concepts it
could use in developing a rear detection system that would best prevent
backover crashes. These ideas included the specific areas that would
need to be detected by a rear visibility system, the design and
possible placements of mirrors or video screens, and the ramifications
of requiring certain systems (e.g., the maintenance costs of video
cameras). This section also contained additional questions regarding
the pricing and feasibility of a variety of potential systems.
    Question 1: NHTSA seeks comment on the areas behind a vehicle that
may be most important to consider when improving rear visibility.
Furthermore, while the distribution of visible area behind the vehicle
was not considered in the blind zone area metrics (e.g., rear blind
zone area) discussed in this document, it may be helpful to specify
some specific areas behind the vehicle that must be visible.
    Responses: Commenters generally fell into two categories. Honda
stated simply that the area immediately behind the vehicle's rear
bumper is significant and should be addressed as a priority. Other
commenters, such as AAM and GM, stated that based on a review of the
SCI data, the area to the sides of the vehicle is of significant
importance, since most victims intruded into the path of the backing
vehicle from the sides, rather than starting from directly behind the
vehicle. Rosco responded, with respect to school buses, that the area
behind the bus closest to the curbside rear wheels may be the most
important in order to see a child running to catch the bus.
    Advocates for Highway and Auto Safety encouraged the agency to make
the coverage area behind the vehicle as large as possible to provide as
much time as possible for the driver to determine that a pedestrian is
behind the vehicle and to take measures to prevent a crash. The
approach recommended by the Advocates was to eliminate vehicles' rear
blind zones entirely. They indicated that allowing the degree of rear
visibility improvement to be based on the size of the particular
vehicle's rear blind zone would permit countermeasures that are
tailored to produce the desired result for each vehicle model and type
individually.
    Question 2: NHTSA invites comment as to how an actual threshold
based on vehicles' rear blind zone area could be defined.
    Responses: This question was asked in relation to the considered
rear visibility threshold, or how big the maximum permissible blind
area could be before a countermeasure was needed. Commenters provided
various responses. GM offered a method of measuring a vehicle's
viewable area indirectly and noted an associated threshold value of
100-125 square feet measured using a 32-inch target plane, but stated
that either the direct or indirect field of view methodology could be
used to determine a threshold. AAM, on the other hand, offered a
suggestion relating to calculating pedestrian speed of 6 kph (3.7 mph),
vehicle speed of 6 kph or less, and estimated driver perception and
response time 2.5 seconds. However, no data were provided by the AAM to
support the specific values. Honda stated that any specified minimum
rear visibility value should be based on conclusive data to indicate a
direct safety benefit that has been found to be cost-effective in light
of all of the related design trade-offs. Consumers Union recommended
that a threshold be established based on NHTSA's Monte Carlo analysis
in which all areas with risk of 0.1 or higher are required to be
visible.
    Question 3: NHTSA is considering specifying a minimum portion of a
vehicle's rear visibility that must be provided via direct vision
(i.e., without the use of mirrors or other indirect vision device).
NHTSA seeks comments on this approach, such as input regarding how a
minimum threshold should be specified, and how much of a vehicle's rear
area should be visible via direct vision?
    Responses: Commenters were generally unsupportive of the idea of a
direct visibility requirement. Honda stated that it would unduly
restrict vehicle design and styling, and stated that it would be a
design-restrictive standard that would not enhance vehicle safety. GM
commented that while there are currently no field of view requirements,
most vehicles provide them, and that market demand for direct field of
view would continue for the foreseeable future. The Alliance stated
that direct field of view should be incorporated into FMVSS No. 111 as
well as indirect field of view. Rosco was concerned that it would be
impossible for some vehicles, particularly larger vehicles, to meet any
direct visibility requirements.
    Question 4: NHTSA requests information regarding anticipated costs
for rear visibility enhancement countermeasures.
    Responses: Many specific responses to this question were provided
on a confidential basis, which were taken into account in the agency's
cost and benefit analysis. However, Kids and Cars did comment that the
agency's estimated costs were too high, and that it did not take into
consideration the amount of money saved by the reduction in minor
parking accidents. Nissan urged NHTSA to consider the ``total cost'' of
implementation of any countermeasure in its cost-benefit analysis. It
stated that the total cost includes equipment, research and
development, software redesign, wiring, electrical architecture,
instrument panels, etc. It also stated that the costs can be especially
significant for vehicles that do not already have an integrated liquid
crystal display (LCD).
    Question 5: Given the increasing popularity of LCD panel
televisions and likely resulting price decline, what decline in price
can be anticipated for LCD displays used with rearview video systems?
Will similar price reduction trends be seen for video cameras for
rearview video system application?
    Responses: GM suggested that substantial changes in price were not
likely in the foreseeable future, although not impossible. The company
stated that while it is conceivable that cost reductions will be
realized, the more severe requirements for automotive LCD displays than
for home applications puts them in a different category, and that cost
reductions may not be realized for some time.
    Question 6: NHTSA requests information on the estimated price of
rear visibility enhancement countermeasures at higher sales volumes, as
well as the basis for such estimates.
    Responses: In response to this question, GM stated that it did not
estimate that there would be any significant cost reductions. It noted
that ultrasonic technology and mirrors have existed for some time, and
that cost reductions are unlikely.
    Question 7: NHTSA requests any available data on rearview video
system maintenance frequency rates and replacement costs. How often are
rearview video cameras damaged in the field?
    Responses: In general, commenters suggested that the number of
warranty claims on rearview video systems was low. However, it was
noted that the systems are still comparatively young. GM stated that
its current warranty rate for rear video systems is approximately 0.1-
2.3 incidents per thousand vehicles.

Nissan stated that it is unaware of any issues that have arisen with
regard to the damage rate of its systems. Mercedes provided
confidential comments on this subject, which were also considered by
NHTSA.
    Question 8: NHTSA requests comments on which types of possible rear
visibility enhancement countermeasure technologies may be considered
for use on which types of vehicles. This information is important for
estimating the costs of countermeasure implementation in the fleet.
    Responses: This question also generated a variety of responses. GM
stated that market forces are driving larger vehicles, such as SUVs and
vans, to adopt rearview video systems. Rosco also suggested that larger
vehicles would benefit most from having a rearview video system
installed. Honda, on the other hand, suggested that rearview video
systems would be better than mirrors on sedans and coupes, but with
pickups, durability and tailgate placement must be considered. Finally,
AAM stated that as a reasonably priced baseline, the ECE R46 mirror
standard would be a good addition, and that for certain vehicles,
countermeasures could supplement the mirror system. It is not clear to
NHTSA whether AAM was suggesting convex mirrors should be required (and
disallow current flat mirrors) or simply that convex mirrors should be
allowed as an option.
    Question 9: NHTSA requests information regarding available studies
or data indicating the effectiveness of dashboard display-based
rearview video systems and rearview mirror based rearview video
systems. What are the key areas that will impact the real-world
effectiveness of these systems as they become more common in the fleet?
    Responses: GM suggested that as drivers grow more familiar with in-
mirror and in-dash video systems as backing aids, the effectiveness of
these systems will increase, and pointed to a study presented at the
May 2008 Society of Automotive Engineers (SAE) Government/Industry
meeting, suggesting that the rearview mirror-based displays showed more
benefits for inexperienced drivers, while more experienced drivers
experienced about equal benefits from each type of system. The Alliance
admitted it had no data, but said it believed the same thing. Rosco
made several arguments for the ``integration'' of dashboard and
rearview mirror-based systems, namely that integration will make the
display more theft resistant and help propagate other technologies.
    Question 10: NHTSA requests objective data on the use,
effectiveness, and cost of rear-mounted convex mirrors.
    Responses: Commenters provided little new data in response to this
question. GM pointed to its earlier response regarding convex mirrors,
where it stated that they did not show substantial safety benefits.
Additionally, AAM stated that rear-mounted convex mirrors were
essentially parking aids, and would not be effective in preventing
backover crashes.
iv. Options for Measuring a Vehicle's Rear Visibility
    In this section, NHTSA asked a series of extremely specific
questions relating to methodologies for measuring the direct rear
visibility of vehicles. These questions focused on various aspects of
the test procedures outlined in the ANPRM, such as how to set up the
machines, what size dummies to use, and how to adjust rear head
restraints so as to balance concerns between rear passenger safety and
rear visibility.
    Question 1: NHTSA requests comment on the use of the 50th
percentile male driver size as a midpoint in terms of driver height and
whether using multiple driver heights for these tests [to determine
direct visibility] would cause undue hardship relative to the safety
value of assessing different driver heights. Specific information
regarding additional cost, if any, that would be incurred by vehicle
manufacturers due to the use of different driver sizes for these
different portions of FMVSS No. 111 is requested.
    Responses: Commenters suggested a range of testing alternatives
that could be used to measure a vehicle's direct visibility
characteristics. GM stated that the 95th percentile eye-ellipse is used
by manufacturers as the tool for evaluating visibility and is
recognized in FMVSS No. 111, and that it would be consistent to apply
that tool to determine rear visibility under the standard as well.
Similarly, Nissan also recommended NHTSA investigate use of an eye-
ellipse method (in accordance with the Society of Automotive Engineers
Recommended Practice J941), rather than using the 50th percentile male
driver's eye locations. Alternatively, Sony suggested that NHTSA
``should use a worst-case-scenario driver body size when conducting
rear visibility measurements, such as the 25th percentile female, or at
the least correlate size with the actual size of people involved'' in
real backover crashes. A third alternative was suggested by AAM, which
stated that the eyepoints and other incidentals of ECE R46 should be
used in developing the criteria for FMVSS No. 111 visibility
requirements. Honda, in its comment, did not offer a specific
suggestion, but rather noted that using a variety of driver heights and
eyepoints might encourage manufacturers to enlarge the mirror or change
the curvature, which would add cost to the development and
implementation of the system. Consumers Union stated that it did not
see the need for a 95th percentile male test, as taller drivers always
have a better view behind the vehicle. The organization stated that it
has tested using only the 50th percentile, although testing at the
eyepoint of the 5th percentile female would also be worthwhile.
    Question 2: NHTSA has been using seating position settings
recommended by the vehicle manufacturers for agency crash tests. For
most vehicles, the vertical seat position setting recommended for seats
with vertical adjustability is the lowest position. NHTSA seeks comment
on whether this setting is the most suitable position for a 50th
percentile male, or if a midpoint setting would be more appropriate for
measuring rear visibility. NHTSA also seeks comment on whether the
specific crash test seating specifications used are the most
appropriate for this context.
    Responses: Nissan, GM, and AAM commented in response to this
question. They indicated that their responses to the previous question
also applied to this issue. Honda pointed out the driver's eyepoint
used affects visibility performance with rear-mounted convex mirrors,
but does not affect the area behind a vehicle that is displayed by a
rearview video system. Honda suggested that if a rule were to require
accommodation of different driver sizes that manufacturers may modify
the mirror to enlarge its size of change the radius of curvature. While
Honda noted that such consideration would result in increased costs,
although it did not specifically discourage this if NHTSA could show
related enhanced safety benefits. Additionally, Honda stated that while
the driver eyepoint is extremely relevant for direct view measurements,
it would have no effect on rearview video systems.
    Question 3: NHTSA seeks comment on the placements of head
restraints. For example, would our test procedure result in the
elimination of rear head restraints or a reduction in their size? If
so, please identify the affected vehicles and explain why the rear head
restraints particularly impair visibility in those vehicles. Similarly,
NHTSA seeks comment on the approach to setting the

longitudinal position of all adjustable head restraints for rear
visibility measurements. While longitudinally adjustable head
restraints positioned fully forward may minimize the chance of
whiplash, a more reasonable option for this test may be to position the
head restraint at the midpoint of the longitudinal adjustment range.
    Responses: NHTSA received comments on this subject from GM, Honda,
Sony, and AAM. GM and Sony suggested that head restraints should be
accounted for, as they contribute substantially to vehicle safety.
Honda stated that head restraints should be adjusted to their lowest or
stored position for rear visibility measurement, and that a direct
visibility requirement should take into consideration the existence of
safety features such as the center high-mounted stop lamp and rear
window wiper and defogger. Honda added that if NHTSA believes the
required head restraints unduly affect rear visibility, the agency
should re-evaluate the recent upgrade of FMVSS No. 202a, Head
Restraints, for which applicability took effect on September 1, 2009,
and take into account rear visibility considerations. The AAM commented
that the recently-updated standard FMVSS No. 202a has the effect of
reducing rear visibility, and that NHTSA should adjust the head
restraints to their lowest position for direct visibility testing
purposes, similar to the procedures in ECE R46.
    Question 4: In our testing, we found that the laser beam is
difficult to detect visually. Therefore, we used the laser detector.
NHTSA invites comment on the availability of other options for
detecting the laser beam as used in this test that does not involve the
use of an electronic laser detector.
    Responses: GM and the AAM both responded to this question by noting
the difficulties in using laser-based methods. GM stated that while it
did not know of any better alternative methods for detecting lasers
than what NHTSA described, it would likely use a math-based alternative
to certify compliance. Similarly, the AAM stated that the European
experience with laser measurement has generally been found to be
cumbersome and that CAD-based measurement might be a more desirable
option.
    Question 5: For locating the laser devices at the selected driver
eyepoints, is there another device besides the H-point device which can
be utilized for this purpose? For simplicity, should eyepoints be
indicated in a similar fashion as is currently in FMVSS No. 111 for
school bus testing in which a single eyepoint is located at a specified
distance from the seat cushion/seat back intersection and within a 6-
inch semi-circular area?
    Responses: GM recommended an alternative in which the eye location
would be specified from a body fiducial point on the vehicle, similar
to methods used in evaluating mirrors under the current standard. AAM
questioned whether any single eye location could be representative, and
if the proposed measurement method was capturing what was important for
rear visibility. AAM also stated that the view in mirrors, which was
not contemplated as part of the direct visibility measurement, was an
important aspect to consider, especially for older drivers whose range
of movement may be limited. Honda stated that it did not consider the
school bus measurement method appropriate for passenger vehicles,
because that measurement method was designed by contemplating the
movement of a bus driver's head.
v. Options for Assessing the Performance of Rear Visibility
Countermeasures
    In determining a rear visibility threshold, NHTSA would first need
to define a test area, from which the vehicle's viewable area could be
subtracted, thereby calculating the size of the blind zone. These
questions were asked in order to solicit comment on what that test area
should cover, as well as other issues related to testing countermeasure
performance.
    Question 1: NHTSA invites comments on the need for and adequacy of
the described area which rear visibility countermeasure systems may be
required to detect obstacles. NHTSA is particularly interested in any
available data that may suggest an alternative area behind the vehicle
over which a rear visibility enhancement countermeasure should be
effective? Is the described area of coverage unrealistically large? Is
it adequate to mimic real world angles at which children may approach
vehicles?
    Responses: Many commenters used this question to comment on the
number of instances in the SCI cases where the victim entered the
vehicle's path from the side of the vehicle. Sony and Kids and Cars
both stated that consideration should be given to areas to the sides of
the vehicle, with Kids and Cars stating that all of the areas not
visible directly or through side mirrors should be taken into
consideration. GM and the AAM both stated that driver's-side convex
mirrors, which have a wider field of view than that required by FMVSS
No. 111, would help to prevent many of these incidents. Nissan
commented that the area visible in side mirrors permitted in ECE R46
should be factored into the measured field of view of a vehicle. Sony
stated that limiting the test are to the edges of the vehicle would
fail to account for obstacles that move into the rear blind zone from
the outside of the immediate rear of the vehicle. Sony suggested that
the test area should account for, at a minimum, vehicle backing speed,
driver reaction time, and the speed of potential obstacles.
    Question 2: Is it reasonable to define the limits of the test zone
such that it begins immediately behind the rear bumper for the test
object defined here or should a gap be permitted before the visibility
zone begins? What additional factors should the agency consider in
defining the zone?
    Responses: Commenters generally split into two groups in responding
to this question. Some supported the idea that the test area should
begin at the edge of the bumper. Kids and Cars suggested that the test
area should begin at the rear bumper because when children approach a
vehicle from the side, they frequently intersect the path of the
vehicle close to the bumper. Rosco stated that coverage should begin at
a vertical plane tangent to the rearmost surface of the rear bumper.
Consumers Union also stated that they believe no gap should exist in
the test zone. Nissan stated that as long as the target area size is
realistic, it would be appropriate to define the limits of the test
zone such that it begins immediately behind the rear bumper. GM and
Honda, however, supported the idea of a gap. GM stated that as most
accidents either come from the sides or from the area 3-8 meters behind
the vehicle, a gap in the area would not be unreasonable. Honda also
supported a small gap of 0.3 meters (1 foot), noting that if no gap
were permitted, video cameras might be placed in locations that could
be subject to damage in low-speed collisions, thereby increasing the
cost of ownership.
    Question 3: NHTSA requests comments on potentially requiring only
the perimeter of the specified area to be tested for rear visibility
enhancement systems. For video-based rear visibility countermeasure
systems, NHTSA assumes that confirming the visibility of the test
object over the perimeter of the required area is sufficient, since a
system able to display the object at the perimeter of the required area
should also be able to display the object at all points in between the
extremities. Is this a reasonable assumption?
    Responses: We received two comments in response to this specific

question. GM stated that this was not an unreasonable suggestion for a
single rearview video camera, but that it did not take into
consideration a system made up of multiple sensors or cameras with
limited lateral scope. Rosco also questioned this assumption, stating
that this did not take into account the fact that an obstruction such
as a marker light could block out some portion of the rearward view.
The Alliance also referenced its earlier comments on threshold
detection (regarding the need for detection zones behind the vehicle),
as well as the zones of coverage provided by ECE R46-compliant side
mirrors.
    Question 4: Would vehicles with rearview video cameras mounted away
from the vehicle centerline have the ability to detect the test object
over the area under consideration? Is there flexibility to relocate
such off-center cameras to meet the requirements under consideration,
if necessary?
    Responses: This question elicited several responses. Honda and
Nissan suggested that it may be possible, but that moving the position
of a video camera could be expensive. They recommended allowing as much
design flexibility as possible. The AAM also stated that limiting video
placement to the centerline would be overly restrictive. Rosco and
Sony, two equipment manufacturers, stated that current technology did
allow a video camera to be mounted off-center and still be able to see
the entire test area, depending on the specifics of that area.
    Question 5: NHTSA seeks comment as to the availability of any
mirrors that may have a field of view that encompasses a range of 50
feet, as well as the quality of image that might be provided over such
a range. How different is the image size and resolution, and how
significant are the differences to the mirrors' potential
effectiveness?
    Responses: No commenters stated they believe that rear mirrors
could have an effective field of view that extends 50 feet. Nissan
stated that it is difficult to describe variation in image size and
resolution, as it varies by the mirror's fixed location on the vehicle
body. Rosco stated that image sizes for rear cross-view mirrors become
diminished beyond 30 feet. Honda questioned whether mirrors could
provide a field of view that extended 50 feet back, but also questioned
whether this was necessary for a typical backing maneuver.
    Question 6: If a gap is permitted behind the vehicle before the
visibility zone begins, how will systems prevent children who may be
immediately behind a vehicle from being backed over?
    Responses: In response to this question, Sony and Rosco stated that
it would not be possible to prevent these backover crashes if the area
in which the child was located was not visible to the driver, and
reiterated that no gap in the visible zone should be permissible. GM,
while acknowledging that not all backover crashes can be prevented,
stated in its comments that NHTSA should focus on mitigating specific
risks by focusing on the crashes that happen most often--incursions and
instances where the vehicle is turning; and by focusing on vehicles
that are statistically overrepresented in backover crash fatalities.
    Question 7: NHTSA seeks input on what level of ambient lighting
would be appropriate to specify for conduct of this compliance test.
What other environmental and ambient conditions, if any, should the
agency include in the test procedure?
    Responses: Several commenters agreed that rear detection systems
should be able to function in low light conditions. Kids and Cars and
Rosco both stated that the systems should be able to work in dark
conditions, while Honda and GM suggested that the low light conditions
be specified with respect to the photometric requirements of backup
lamps, which would be illuminated during a backing maneuver. Sony
suggested that rear detection devices should function in 5 lux
luminosity, which is slightly higher than the 3 lux suggested by GM.
    Question 8: NHTSA invites input regarding the composition of the
countermeasure compliance test object and the types of technologies
that are likely to be able to provide coverage of the related test
area.
    Responses: In response to this query, AAM stated that based on
Centers for Disease Control (CDC) growth data charts, it recommended a
test object that is cylindrical with a diameter of 15 cm and a height
of 82 cm. Kids and Cars, alternatively, suggested a test object with a
height of 28 inches, or approximately 71 cm. Honda did not provide a
specific suggestion, but noted that the test object should reflect the
age and height of the people at risk and not be made of materials that
cause excessive reflection or have other characteristics that could
interfere with the goals of a practical, reliable, and repeatable test.
Similarly, Sony stated that the test object should simulate the size of
a 1-year-old child. Finally, GM noted that it provided information on
this topic as part of its involvement in NHTSA-sponsored cooperative
research with the Virginia Tech Transportation Institute focused on
advanced crash avoidance technologies relating to backover avoidance.
vi. Options for Characterizing Rear Visibility Countermeasures
    In this section, NHTSA sought comments that would provide insight
into what specifications, if any, the agency should mandate for rear
visibility enhancements. In the ANPRM, NHTSA noted a general lack of
relevant existing industry consensus standards which could be
considered in establishing regulatory performance requirements. The
agency also noted it appeared there was no ongoing development to
establish such consensus standards in the United States. Of particular
interest were any standards that were being applied to specific types
of countermeasures (such as sensors or cameras) by manufacturers. The
agency also wanted to solicit comment on other considerations, such as
display characteristics, durability measurements, or test procedures
that could assist it in drafting a comprehensive proposed requirement.
Questions posed also sought assistance in the identification of any
additional parameters which the agency may need to consider specifying
in a regulatory amendment to FMVSS No. 111.
    Question 1: Are there any existing industry consensus standards for
rear visibility enhancement systems which address the parameters
outlined in this section? Are there any ongoing efforts to develop such
industry consensus standards? If so, when will the standards be
published?
    Responses: Commenters generally agreed with NHTSA that industry
consensus standards do not exist. Some commenters, such as Rosco, and
Ford, cited international standards for items such as sensor
performance and display requirements. Honda stated that ISO is
currently reviewing performance requirements and test procedures for
``Extended Range Backing Aids (ERBA)'' but that this document is not
directly addressing backover incidents as NHTSA did in the ANPRM and
that timing-wise, the document could be balloted by ISO and issued as
soon as the end of 2009 or early 2010. Nissan noted that while there is
a lack of existing industry consensus standards for rear visibility
enhancement systems, there does not appear to be wide variation between
systems offered by different automakers due to the small number of
rearview video camera suppliers.

    Ford cited the initiation of updates to ECE R46 for rearview video
displays and stated that while it did not support the standard in its
entirety, it believes the Australian state of New South Wales'
Technical Standard No.149 \56\ is instructive with regard to display
image. Ford stated that this standard requires a cylinder test object
located 5 meters from the rear of the vehicle to have a corresponding
image height on the display of at least 0.5 percent of the distance
between the driver's eye and the display. For example, for a driver's
eye located 800 mm from the screen, the corresponding minimum height
for the image on the display would be 4mm.
---------------------------------------------------------------------------

    \56\ Australian Design Rule 14/02 Rear Vision Mirrors; 2006.
---------------------------------------------------------------------------

    The most extensive comments received were in regard to ISO
17386:2004 Transport information and control systems, Manoeuvring Aids
for Low Speed Operation (MALSO). This standard contains test
specifications and requirements to establish the ability of a sensor-
based system to detect stationary objects, primarily in the utilization
as a parking aid. Delphi stated that tests used for system
certification under this standard utilize an idealized target, a PVC
pole, for uniform and repeatable performance. The tests were designed
to ignore the area from 0 to 25 cm above the ground to prevent
detection of parking curbs, presumably to limit the number of times the
system alerted the driver to their presence so that drivers would not
disable the system. As noted by the AAM, ISO 17386 pertains
specifically to systems designed to assist drivers in maneuvering in
tight spaces, such as in low-speed parking maneuvers. The AAM further
noted that the parameters addressed in the ISO standard are not
relevant for pedestrian impacts, nor are the systems designed for low-
speed maneuvering optimized for pedestrian detection. Delphi identified
the need for a more realistic target specification to be developed,
compared to the ISO standard, for sensor-based systems to be able to
detect small children. Ackton stated that up to this point, ISO's MALSO
standard with the PVC target pole has been the benchmark for all
equipment manufacturers. However, Ackton stated that many manufacturers
have created systems that ``go beyond'' the requirements of the ISO
standard and that its own ``New-Gen'' system utilizes technology that
allows it to detect moving objects.
    The AAM stated that ISO and SAE have several standards that pertain
to human-machine interface (HMI) aspects including features employed by
rearview video systems and sensor-based backing aids. It noted that
these standards are recommendations, rather than specifications, due to
the contingent nature of most HMI parameters, which are highly
influenced by the specific context and implementation in question. The
AAM concluded by stating that such standards do not lend themselves for
incorporation into an FMVSS for rearward visibility.
    Question 2: Are there additional parameters which should be
specified to define a rear visibility enhancement system? What should
the minimum specified performance be for each parameter?
    Responses: Gentex suggested a minimum visual display brightness of
500 cd/m\2\ for in-mirror displays, as measured at room temperature and
in a dark room. Its rationale was that automaker research has confirmed
this to be the minimally accepted value, presumably to account for a
wide possible range of ambient conditions.
    Magna suggested that instead of regulating operational areas of
video camera performance that NHTSA instead leave implementation to the
automakers and suppliers to address to ensure overall system
affordability.
    Question 3: Are future rear visibility systems anticipated which
may have significantly different visual display types that may require
other display specification parameters?
    Responses: NHTSA did not receive comments in response to this
question.

IV. Analysis of ANPRM Comments and NHTSA's Tentative Conclusions

    Based upon the discussion in the ANPRM and the comments received,
we have grouped the various ideas for mitigating backover crashes into
five distinct threads. While there are numerous variations within each
concept, we believe that these five concepts contain substantially all
of the potential solutions discussed. The ideas are as follows: (1) The
improvement of rear visibility for all vehicles within the scope of the
K.T. Safety Act; (2) the improvement of rear visibility for certain
high-risk vehicle types, namely those judged to be involved in a
disproportionately high number of backover crashes; (3) the improvement
of rear visibility for vehicles with blind zones that exceed a
threshold or cannot view areas deemed to be critical; (4) the
installation of driver's-side convex mirrors; and (5) the installation
of advanced technology systems, such as combinations of sensors and
video cameras, automatic braking systems, or other technology. We note
that when referring to improved rear visibility via a
``countermeasure,'' the term refers to any rearview video system,
sensor, or mirror, although we discuss the specific differences between
those technology types in the earlier ANPRM summary and in section V
below. This section contains NHTSA's analysis of the various overall
approaches that could be applied to backover prevention, as well as
addresses comments germane to the discussion.
    Following the discussion of comments relating to the possible means
for improving rear visibility and mitigating backover crashes and
comments received regarding these, a discussion of comments relating to
possible rear visibility system characteristics and compliance test
methods is presented.

A. Application of Rear Visibility Systems Across the Light Vehicle
Fleet

    One approach considered by NHTSA in the ANPRM was to require that
all vehicles with a GVWR of 10,000 pounds or less be subjected to
improved rear visibility requirements. Going forward with a requirement
for improved rear visibility for all light vehicles was an idea
supported by a variety of commenters. First and foremost, safety
organizations and individuals whose families had been involved in
backover incidents strongly favored this alternative. In general, these
commenters supported the most comprehensive possible proposal in order
to achieve the maximum possible benefits, pointing out the particular
tragedy that many of these incidents involved a parent or other family
member injuring or killing their own children. Kids and Cars stated
that all vehicles must be addressed in order to prevent backover
injuries and fatalities, stating that even one car with a large blind
zone should indicate the need for the regulation to cover all vehicle
types. Similarly, IIHS and Consumers Union both supported uniform
requirements across light vehicle classes.
    Several equipment manufacturers also were in support of requiring
improved rear visibility on all light vehicles. Sony commented that the
Act permits NHTSA to ``prescribe different requirements for different
types of motor vehicles,'' but does not permit a total or partial
exemption of a particular class of vehicles, or a percentage of a
particular class of vehicles, from rear visibility requirements. Sony
further stated that limiting the rear blind zone visibility
requirements to LTVs ignores the fact that passenger cars account for
26 percent of backover deaths and 54 percent of backover injuries, and
that

these percentages will likely increase given the relative decline of
LTV sales across the market. Delphi and Magna stated their belief that
the backover problem is widespread enough that improved rear visibility
requirements should not be limited to any particular class of vehicles.
Similarly, Ackton suggested that rear visibility countermeasures should
not be limited to a certain vehicle class and also raised the issue
that trailers could be equipped with sensor-based object detection
systems.
    In contrast to this broad approach, some automakers commented in
favor of limiting any rear visibility improvement to just a portion of
the fleet, such as LTVs, saying that, in terms of fatalities, they are
statistically overrepresented in backover crashes. Nissan and GM both
recommended that a maximum blind zone area approach be used to
determine whether a particular model of vehicle warrants improved rear
visibility, and recommended against the application of any new
requirements by vehicle type. Mercedes suggested that if the agency
believes that improved rear visibility should be required for the
portion of the vehicle fleet that is statistically overrepresented in
backover crashes (i.e., LTVs), then NHTSA should apply the requirements
to only those types of vehicles. Honda also commented that rear
visibility performance requirements should be instituted for only those
vehicles with the highest rates of backover incidents, although it also
suggested that NHTSA should actively monitor the data for all vehicle
types so that it can consider broader application of the requirements
based on the safety need.
    Lastly, some vehicle manufacturers generally supported alternative
methods for preventing backovers. One manufacturer, Nissan, requested
that the agency conduct more research before proposing to require any
additional performance requirements for rear visibility. The AAM
limited its support to the requirement for ECE R46-compliant convex
side mirrors, instead of more advanced countermeasures. Mercedes echoed
this approach, but allowed that if more advanced countermeasures were
seen as essential, they be limited to LTVs, and not applied to
passenger cars. The application of improved rear visibility
requirements to LTVs only was also supported by Honda. GM was the lone
manufacturer that recommended that NHTSA limit the requirement for
improved rear visibility to vehicles with large blind zones only. We
have addressed comments relating to those alternative proposals in the
sections below.
    While NHTSA agrees that requiring enhanced rear visibility for all
light vehicles would be the most comprehensive approach to mitigate
backover crashes, it would also entail the highest costs of any
possible proposal. Commenters also suggested that NHTSA's projected
costs were too high and that costs would likely decline once systems
such as these were put into wider production. In response to these
comments, NHTSA has more fully analyzed the costs and benefits of the
proposal in the preliminary regulatory impact analysis (PRIA), which is
presented in tandem with this document.
    As described in Section II.B, NHTSA has tentatively decided to
require improved rear visibility for all vehicles with a GVWR of 10,000
pounds or less. Having taken into account the intent of Congress in
passing the K.T. Safety Act, the smaller, yet still-significant number
of fatalities involving passenger cars, and the fact that the injury
rate for all classes of vehicles is approximately proportional to their
representation in the fleet, we do not at this time believe it is in
the best interest of safety or otherwise appropriate or permissible
under the K.T. Safety Act to exclude passenger cars from rigorous rear
visibility performance requirements. Passenger cars account for
slightly more than half of the injuries from backover incidents.
    The rationale for proposing to require all light vehicles to have
improved rear visibility is twofold. First, NHTSA, and Congress, are
extremely concerned about the incidence of children being backed over
by light vehicles. This is a phenomenon that is not limited to any
particular vehicle type, and while the ANPRM did discuss blind zone
area measurement, no driver of any type of vehicle could see the entire
area behind the vehicle in which a pedestrian, especially a young
child, might be located without the aid of an effective rear visibility
countermeasure. Therefore, the obvious and most complete solution is to
require an enhancement that enables drivers of all light vehicles to
see children and other obstacles directly behind a vehicle.
    Second, and as noted by some commenters, applying improved rear
visibility requirements to just a portion of the fleet would cause an
awkward safety disparity between vehicles equipped with a
countermeasure, and those without. As NHTSA has noted in the ANPRM and
this notice, driver education about and acceptance of rear visibility
countermeasures is crucial in realizing their effectiveness. To require
visibility improvements in only some vehicles may send a mixed message
to drivers that would not achieve the intent of the law.

B. Limitation of Countermeasure Application to Certain Vehicle Types

    A second concept explored in the ANPRM was the idea of limiting the
requirement for improved rear visibility to certain vehicle types. The
idea of having different rear visibility requirements for certain
vehicle types was explicitly contemplated by Congress and articulated
in the text of the K.T. Safety Act, which stated that ``The Secretary
may prescribe different requirements for different types of motor
vehicles to expand the required field of view to enable the driver of a
motor vehicle to detect areas behind the motor vehicle to reduce death
and injury resulting from backing incidents, particularly incidents
involving small children and disabled persons.'' Furthermore, we
believe that in particular, vehicles like multipurpose passenger
vehicles and pickup trucks were contemplated by Congress as potentially
warranting more of an improvement in rear visibility than do passenger
cars. In noting the need for rear visibility performance requirements,
the legislative history stated that, ``As larger vehicles, including
SUVs, pickup trucks, and minivans, have become more popular, more
drivers are confronted with larger blind spots.'' \57\
---------------------------------------------------------------------------

    \57\ S. Rep. 110-275, S. Rep. No. 275, 110TH Cong., 2nd Sess.
2008.
---------------------------------------------------------------------------

    In the ANPRM, NHTSA considered whether it would be appropriate to
take this idea further and limit the requirements for improved rear
visibility to the vehicles known as ``LTVs,'' which include
multipurpose passenger vehicles, trucks, and minivans with a GVWR of
10,000 pounds or less. The agency reasoned that if a strong
relationship between vehicle class and backover incidents existed, a
targeted requirement for advanced rear visibility countermeasures could
achieve a large percentage of the overall benefits of the technology at
a fraction of the overall cost to the industry. Therefore, the agency
conducted a statistical analysis and requested comment on the option.
    The agency's analysis revealed that while LTVs were statistically
overrepresented in backover-related fatalities, they were not
significantly overrepresented in backover-related injuries or in
backover crashes

generally. Table 7 below lays out a summary of the results.\58\
---------------------------------------------------------------------------

    \58\ This table is presented in more detail in section III of
the PRIA.

 Table 7--Backover Crash Fatalities and Injuries and Percent of Fleet by
                              Vehicle Type
------------------------------------------------------------------------
 Vehicle type (GVWR of 10,000 lb    Percent of   Percent of   Percent of
             or less)                 fleet       injuries    fatalities
------------------------------------------------------------------------
Passenger Car....................           58           54           26
Multipurpose Passenger Vehicle...           16           20           30
Truck............................           17           18           31
Van (including minivans).........            8            6           13
------------------------------------------------------------------------

    As shown by Table 7, LTVs represent a disproportionate share of the
overall backover-related fatalities, being involved in almost twice as
many fatalities as their portion of the fleet. Conversely, passenger
cars are represented in only one half as many fatalities as their fleet
percentage would indicate. We note that this discrepancy is spread
relatively evenly across multipurpose passenger vehicles, trucks, and
vans.
    However, unlike fatalities, the relationship between backover
crashes generally and vehicle type for injuries is proportional to a
vehicle type's proportion of the fleet. The data show that passenger
cars are just as likely to be involved in a backover incident as are
other types of vehicles. The substantially similar numbers of total
backovers (including injuries and fatalities) between vehicle types
cast doubt on whether it would be in the best interest of safety to
limit rear visibility improvement to just LTVs even if it were
permissible to do so.
    As indicated in the comment summary section above, commenters were
split on the idea of imposing countermeasure requirements by vehicle
class. Vehicle manufacturers in favor of a requirement that would
affect only LTVs included Honda and Mercedes, while Nissan was against
such a proposal. Mercedes suggested that if the agency believes that
advanced countermeasures are required for the portion of the vehicle
fleet that is statistically overrepresented in backover crashed (i.e.,
LTVs), then NHTSA should require those countermeasures only for those
types of vehicles. Nissan stated that it supported using a blind zone
threshold, rather than vehicle class, to determine which vehicles
require improved rear visibility. Honda also commented that rear
visibility performance requirements should be instituted for only those
vehicles with the highest rates of backover incidents, although it also
suggested that NHTSA should actively monitor the data for all vehicle
types so that it can consider broader application of the requirements
based on the safety need. Consumers Union made statements that they did
not support improving rear visibility for only a portion of the light
vehicle fleet, but they did not provide any data or rationale to
support the statements.
    GM commented that the data provided in the ANPRM indicate that LTVs
have a larger blind zone than most passenger cars, and that it can be
extrapolated that the increased rate of LTVs in backing crashes could
be the result of larger blind zones. Based on this idea, GM stated that
this suggests the focus of the rulemaking should be on vehicle blind
zone, not vehicle class. However, while NHTSA had considered this
correlation, as described above, the agency has found that the
relationship between rear visibility and backover crashes appears to
involve too many factors to permit isolation of only the impact of rear
visibility. This preliminary information suggests that the statistical
overrepresentation of LTVs in backover crash incidence is not solely an
effect of a vehicle's rear visibility characteristics.
    Blue Bird submitted a comment requesting that smaller buses not be
subject to any new rear visibility requirements. As it noted, the
language of the K.T. Safety Act would include small buses as part of
the class of vehicles potentially affected by the regulation. However,
Blue Bird offered several reasons why it believes that it would be a
better policy decision to exclude buses from the rear visibility
requirement. First, it pointed to the fatality and injury data
presented in NHTSA's ANPRM, which indicated that buses, which were
included in the ``Other Light Vehicle'' category, were involved in no
fatalities and few injuries. Second, Blue Bird stated that many small
buses (including small school buses), are not equipped with navigation
or multifunction screens. The commenter added that the increased costs
could deter some school districts from purchasing new school buses,
which could lead to safety disbenefits. Third, Blue Bird noted that
most drivers of buses must have commercial driver's licenses, and many
are subject to far more training than drivers of passenger vehicles.
    We note that another commenter, Rosco, stated conversely that small
buses should be subject to improved rear visibility requirements. It
argued that small buses, frequently used for special needs children,
are frequently used in situations around children. Rosco stated that
because these vehicles have limited rearward visibility, they should be
equipped with rearview video systems. However, Rosco also notes that
operational guidelines (buses, in particular school buses, are driven
by professional drivers) advise against traveling in reverse in normal
operations. Furthermore, the statistics indicate that despite their
proximity to children, the guidelines are effective, as our data
indicates relatively few backover incidents involving school buses.
    We received no comments regarding LSVs.
    While sensitive to the issues cited by Blue Bird regarding school
buses, we are proposing that school buses and low-speed vehicles also
be included. We believe that it is apparent from the legislative
history that Congress intended for this statute to address the problem
of backover crashes involving all vehicles with a GVWR of 10,000 pounds
or less. Therefore, we are proposing to include all passenger vehicles
among the vehicles subject to the enhanced rear visibility requirements
without exception.

C. Using Blind Zone Area as a Basis for Countermeasure Requirement

    One option presented in the ANPRM was to limit the requirement for
improved rear visibility using a vehicle's blind zone area (the area

behind a vehicle that cannot be seen directly through the vehicle's
rear windows) threshold. This option was based on the preliminary
indication that certain vehicles with larger rear blind zones may be
more prone to backover incidents.
    In their comments, some vehicle manufacturers commented in favor of
using a rear blind zone area threshold to determine which vehicles
would need improved rear visibility. GM recommended that a maximum
blind zone area approach should be used to determine whether a vehicle
should be equipped with a countermeasure, and recommended against the
application of countermeasures by vehicle type. GM offered a method of
measuring a vehicle's viewable area indirectly and noted an associated
threshold value of 100-125 square feet measured using a 32-inch target
plane, but stated that either the direct or indirect field of view
methodology could be used to determine a threshold. While GM commented
extensively on how its indirect field of view measurement method
correlated with and had some advantages over NHTSA's direct visibility
method, it did not provide any additional information to aid in
correlating measured direct rear visibility with backover incidents.
    AAM, on the other hand, offered a suggestion relating to
calculating minimum required field of view using a pedestrian speed of
6 kph (3.7 mph), vehicle speed of 6 kph or less, and estimated driver
perception and response time 2.5 seconds. However, no data were
provided by the AAM to support the specific values offered.
    Nissan also supported a maximum blind zone area approach to
identifying which vehicles most warranted improved rear visibility.
However, it did not provide any data or specific recommended value and
associated justification for its use as a blind zone area threshold.
    Consumers Union recommended that a threshold be established based
on NHTSA's Monte Carlo analysis in which all areas with risk of 0.1 or
higher are required to be visible. However, no justification was
provided for choosing 0.1 as a risk threshold as opposed to some other
value.
    While several commenters stated that they supported use of a blind
zone area threshold approach to determine which vehicles should have a
countermeasure, those comments did not provide any data in addition to
what NHTSA presented that might support such a proposal.
    As described in the ANPRM, to determine a suitable blind zone area
threshold value at which vehicles with larger blind zones would be
required to have a improved rear visibility, NHTSA plotted the average
ratios of backing crashes to non-backing crashes and backover crashes
to non-backing crashes versus the direct-view rear blind zone areas for
28 vehicles, as shown in Figure 1. These 28 vehicles were selected
because they were the ones for which NHTSA had measured direct rear
visibility and for which sufficient state crash data were available.
[GRAPHIC] [TIFF OMITTED] TP07DE10.007

    Upon further examination, NHTSA has determined that using rear
blind zone area to develop a threshold is not feasible at this time. We
believe that the 28 vehicles we used to develop Figure 1 do not depict
an obvious cutoff point where the risk of a backing crash dramatically
increased with increasing blind zone area and that some vehicles with
small blind zone areas (e.g., less than 300 square feet) have fairly
high backing and backover crash rates. Also, while we found that direct
rear blind zone area measured in a 50-foot square centered behind the
vehicle was correlated with backing crashes to a mildly statistically
significant degree, the relationship between size of the rear blind
zone area directly behind vehicles and backover crash risk, was not
correlated to a statistically significant degree.59 60 60
Finally, during our SCI review, we determined that a majority of the
victims in backover crashes were directly behind the vehicle and within
a range of 20 feet from the rear bumper, an area that is not visible to
the driver in many vehicles of all types.\61\ Therefore, any
requirement for a maximum rear blind zone area that permitted the area
within 20-foot aft of the rear bumper to not be visible to the driver
would fail to address a large portion of backover crashes.
---------------------------------------------------------------------------

    \59\ The correlation between direct rear blind zone area and
backing crashes was correlated to a statistically significant
degree. However, this correlation was not sufficiently strong to use
as a basis for determining a specific threshold.
    \60\ Partyka, S., Direct-View Rear Visibility and Backing Risk
for Light Passenger Vehicles (2008).
    \61\ See analysis of SCI data, section V.B.i.
---------------------------------------------------------------------------

D. Use of Convex Driver's-Side Mirrors

    Several commenters recommended that NHTSA make modifications to the
existing mirror requirements of FMVSS No. 111 in order to realize the
goal of the K.T. Safety Act. Among other requirements, FMVSS No. 111
currently requires a flat mirror on the driver's side, and permits,
although does not require, a convex mirror on the passenger side
(nearly all vehicles are equipped with such a mirror, however). NHTSA
notes that FMVSS No. 111 does allow exterior rearview mirrors which
incorporate an outer curved portion, as long as the required flat
portion is also present. In the ANPRM, NHTSA did not consider
modification of the existing side mirror provisions of FMVSS No. 111
since we believed it to be an ancillary issue with regard to the rear
visibility activity currently being pursued.
    In their comments on the ANPRM, the AAM, along with several vehicle
manufacturers, recommended that NHTSA adopt European (ECE R46) mirror
specifications to require non-planar side mirrors on both the driver
and passenger sides of light vehicles. They stated that this would
enable drivers to detect a majority of pedestrians involved in reported
backover incidents, as most victims do not begin directly behind the
vehicle, but rather enter the area directly behind the vehicle from one
side or the other. Specifically, the AAM stated that its analysis of
the agency's SCI cases indicated this expanded field of view (from non-
planar mirrors) would cover approximately 80 percent of the cases
investigated for which the pre-crash movement of the pedestrian was
recorded. Furthermore, the commenters stated that the increased field
of view of convex driver's-side mirrors would give drivers a greater
window of time in which they could see an incurring pedestrian in the
side mirror. The AAM stated that using the ECE specification would
result in an increase in the lateral angular field of view up to 286
percent in expanded field of view over that required by FMVSS No. 111
for vehicles meeting passenger car requirements. In addition, the AAM
cited findings from a study which concluded that non-planar mirrors can
increase angular viewing coverage by over 300 percent when compared to
flat mirrors and that spherical and aspheric mirrors with spherical
portions can provide a substantial reduction in glare for drivers under
normal conditions and improvements in lane change situations.
    GM said it agrees with the AAM that 80 percent of the SCI cases are
incursions from the side and could be addressed by modifying existing
mirror requirements to the side and rear of the vehicle, and agreed
with AAM on adopting ECE R46 requirements.
    Mercedes said it supports the AAM's recommendation to adopt ECE R46
requirements for convex exterior mirrors, which it said would
substantially expand the required field of view for all light vehicles
and thereby improve the ability of drivers to detect pedestrians and
pedal cyclists moving into the rearward pathway of the vehicle.
    Conversely, Advocates for Highway and Auto Safety stated that
simple changes in the current requirements for side and interior
rearview mirrors will not fully address the problem of blind zones,
enable drivers to see the entire area immediately behind the vehicle,
or comply with the statutory mandate to ``expand the required field of
view * * *''
    After careful consideration of the comments received, NHTSA
believes that modifications to the side mirror requirements in FMVSS
No. 111 are best handled in a separate rulemaking. We have come to this
conclusion for two reasons. First, given that only marginal gains could
be made in field of view to the sides of the vehicle, we do not believe
that those gains would result in a reduction of backovers. NHTSA's rear
visibility measurements show that rearview mirrors in current vehicles
typically show a much wider area that exceeds the minimum requirements
set forth in FMVSS No. 111, as illustrated in Figure 2 below. As a
result, a fairly wide field of view provided by side rearview mirrors
has already been present in the backover incidents that have occurred
to date. At the extreme lateral distances from the vehicle, in the area
in which an ECE-compliant convex mirror would display but a standard
side-view mirror would not, pedestrians are sufficiently far from a
vehicle that a driver (if the driver was using the mirror) would likely
not perceive a risk that the individual would intersect the vehicle's
path as the vehicle moved rearward.
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    Second, ECE R46 compliant mirrors would not provide a field of view
that includes what the agency has determined, through Monte Carlo
simulation, to be the highest risk areas for backover crashes, which
are the areas directly behind the vehicle. Any areas of crash risk for
a pedestrian behind the vehicle that would fall within the field of
view of a convex side mirror are already well within the field of view
of an existing FMVSS No. 111-compliant side mirror. Thus, we anticipate
that little or no net

improvement in backover rates would occur if there were a switch to ECE
R46-compliant mirrors.
    Notwithstanding these observations, NHTSA plans to reexamine the
side mirror requirements in FMVSS No. 111 in upcoming rulemaking
actions. The suggestions of AAM and other commenters that these mirrors
may provide safety benefits such as glare reduction and lane-change
assistance will be considered in the context of those actions.

E. Advanced Systems and Combination Sensor/Rearview Video Systems

    NHTSA's analyses are based on currently available technology.
However, it is known that additional technologies are under
development, but the quality of their performance is not known at this
time. Two additional sensor technologies are being developed by
manufacturers that could be used to improve a vehicle's rear
visibility: an infrared-based object detection and video-based real-
time image processing for object detection. Infrared-based systems
operate by sensing the infrared radiation emitted by objects located in
their detection range and can produce non-photographic images that
portray the shapes and locations of objects detected. Rear object
detection via video camera uses real-time image processing capability
to identify obstacles behind the vehicle and then alert the driver of
their presence. While these technology applications may eventually
prove viable, because of their early stages of development, it is not
possible at this time to assess their ability to effectively expand the
visible area behind a vehicle.
    NHTSA is currently engaged in cooperative research with the
Virginia Tech Transportation Institute and GM on Advanced Collision
Avoidance Technology relating to backing incidents. The research is
focused on assessing the ability of more advanced technologies to
reduce the occurrence of backing crashes, and refining a tool to assess
the potential safety benefit of technologies, such as an advanced
object detection system with integrated automatic braking capability.
The completion of NHTSA's advanced technology research effort is not
expected until calendar year 2011.
    Commenters including Continental, Magna, and Takata indicated that
they are either developing or anticipate development of advanced
systems with pedestrian detection capability in the future. Nissan
indicated that they are studying some potential future applications
which could limit backing speed, apply automatic braking, or provide
the driver with a haptic (i.e., tactile, e.g., vibration) response \62\
to indicate the presence of a rear obstacle. While future advanced
safety systems may be developed to reduce backover crashes, no systems
are currently ready for market. Therefore, the proposed improved rear
visibility requirements specified in this notice, while not precluding
use of promising advanced technology, cannot be based on the possible
benefits that may be attainable with such future systems.
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    \62\ Providing a driver with a haptic response means providing
tactile feedback such as by causing the steering wheel to vibrate.
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F. Rear Field of View

    In the ANPRM, NHTSA invited comment on what area behind the vehicle
would need to be made visible to the driver in order to best improve
safety. A wide area of up to 50 feet wide by 50 feet long was suggested
as a possible coverage area option. NHTSA inquired about the
feasibility of coverage such a large area and sought comments on which
areas behind the vehicle may be most critical for backover mitigation.
    Multiple commenters discussed the average area that any
countermeasure would be expected to ``see'' and, in particular, noted
the number of SCI cases in which the victim entered the vehicle's path
from the side of the vehicle. Sony and Kids and Cars both stated that
consideration should be given to areas to the sides of the vehicle,
with Kids and Cars stating that all of the areas not visible directly
or through side mirrors should be taken into consideration. Sony stated
that limiting the rear test area to the area within the edges of the
vehicle would fail to account for obstacles that move into the rear
blind zone from outside of the immediate rear of the vehicle. Sony
suggested that the test area should account for, at a minimum, vehicle
backing speed, driver reaction time, and the speed of potential
obstacles. Advocates for Highway and Auto Safety indicated that they
believe that if the area immediately behind a motor vehicle is visible
to a driver, substantial safety benefits will result for pedestrians,
especially very young children.
    Many commenters expressed a desire to minimize or eliminate any
``gap'' between the area that is required to be visible and the rear
bumper. However, the rationale for allowing a gap seemed based to the
difficulty of rear visibility systems might have in detecting areas
directly behind the bumper. Kids and Cars suggested that the area of
required coverage should begin at the rear bumper because when children
approach a vehicle from the side, they frequently intersect the path of
the vehicle close to the bumper. Advocates for Highway and Auto Safety
stated that the countermeasure needs to provide the driver with a field
of view that eliminates the entire blind zone immediately behind the
rear of the vehicle, suggesting that no gap should be allowed.
Consumers Union also stated that they believe no gap should exist in
the test zone. Nissan stated that as long as the target area size is
realistic, it would be appropriate to define the limits of the test
zone such that it begins immediately behind the rear bumper. Rosco
stated that coverage should begin at a vertical plane tangent to the
rearmost surface of the rear bumper. Sony indicated that NHTSA need not
and should not permit any significant gap behind a vehicle before the
visibility zone begins.
    On the other hand, some commenters supported the idea of a gap. The
AORC stated that young children should be visible using a rearview
video system beginning at a distance of 0.25 meters (0.82 ft) from the
rear bumper and extending outward to a minimum distance of 3 meters
(9.84 ft). GM stated that, as most of the documented SCI backover cases
involved pedestrians entering the vehicle's path from the sides of the
vehicle, a gap in the area immediately aft of the rear bumper would not
be unreasonable. Honda also supported a small gap of 0.3 meters (1
foot), noting that if no gap were permitted, video cameras might be
placed in locations that could be subject to damage in low-speed
collisions, thereby increasing the cost of ownership.
    In regard to the size of the visible area behind a vehicle may be
needed to adequately mitigate backover crashes, Advocates for Highway
and Auto safety stated that ``there is no reason why a rearview video
system could not provide an optimal coverage area that is unlimited
when the vehicle is on a flat surface or extends at least 20 feet
behind the vehicle.'' Multiple commenters noted that rear-mounted
convex mirrors could not be modified to attain such a range as was
indicated in the ANPRM. NHTSA's test results for rear-mounted convex
look-down and cross-view mirrors agree with this comment.
Manufacturers' descriptions of current sensor-based systems included in
their comments also did not indicate that sensors could meet this range
requirement. While no comments were received regarding the ability of
rearview video systems to cover this

range, NHTSA's testing has shown that while the systems may display
such a range, image quality decreases as areas further out from the
vehicle are displayed.
    In response to the ANPRM description of NHTSA's Monte Carlo
analysis of backover risk as a function of pedestrian initial location,
GM commented that NHTSA's analysis did not factor in the probability
that a pedestrian would have actually been located at any specific
point on the test grid. While NHTSA agrees with GM's comment, we note
that the only available data for use in asserting such a probability of
pedestrian location would be SCI case data, which is not nationally
representative.
    As will be explained later in this document, based on the above
comments and some new analysis, NHTSA has determined that a coverage
area of 20 feet in length and 10 feet in width (5 feet to either side
of the vehicles centerline) is the most feasible and effective range
for mitigating backover crashes.

G. Rear Visibility System Characteristics

    In the ANPRM, NHTSA noted several possible system characteristics
that may be important to require in order to ensure that the maximum
possible effectiveness of a rear visibility system may be achieved. Our
general approach in establishing performance requirements was to
identify key areas that we believe are pertinent to overall system
effectiveness. In the absence of existing consensus industry standards,
we reviewed existing systems and made determinations regarding
performance areas to specify. These areas include visual display
characteristics and aspects of rearview image presentation. The
following paragraphs summarize comments relating to system
characteristics and describe NHTSA's analysis regarding those possible
specifications.
i. Rearview Image Response Time
    Image response time is the time delay between the moment the
vehicle is put into reverse gear, and the moment which an image to the
rear of the vehicle is displayed by a rear visibility system. The
importance of response time to safety is illustrated by a comment from
Ms. Susan Auriemma, in which she describes having to wait several
seconds for the image to appear and notes that drivers may proceed to
back without waiting for the image to appear. NHTSA agrees with her
concern that if the display takes too long to appear, drivers may be
likely to begin a backing maneuver before the image behind the vehicle
is displayed, rendering the system less effective. In the ANPRM, we
suggested a maximum value of 1.25 seconds for the maximum allowable
time for a rearview video image to be displayed to the driver, or image
response time.
    Commenters generally concurred with NHTSA's concerns regarding
image response time; however, manufacturers identified several
technical issues which merit consideration. While GM and Gentex agreed
that rearview video systems are able to display an image within 1.25
seconds, they noted that based on the complexity of the system and the
need for tolerances, systems can typically take longer to produce
images in some situations due in part to electronic image quality
control checks that are a precursor to the full display of an image.
Therefore, NHTA's suggested maximum value of 1.25 seconds could
unnecessarily restrict the operation of some systems and in theory
impact the electronic quality control approach of manufacturers. GM and
Gentex noted that a maximum image response time value of 2.0 seconds
would allow for timely activation of the system based on a reverse
signal and provide a reasonable tolerance for system variation while
ensuring the availability of an image at the beginning of backing
maneuvers. Specifically, Gentex stated ``In total, a typical
application requires a nominal 1.20 seconds to display a rearview video
image. With tolerance, as much as 2.00 seconds may be required--not
including the time between the gear change * * *'' Gentex went on to
recommend that a maximum image response time of 3.0 seconds allows the
rearview video system enough time to ensure the driver is presented
with a quality video image. However, no data justifying the need for
the additional 1 second was provided by Gentex. While NHTSA understands
that allowing time for system checks may result in a higher quality
image, we also believe that providing an image soon after the vehicle
is shifted into reverse may substantially increase the likelihood that
a driver could detect a rear obstacle, if present.
    AAM recommended that maximum image response time be specified with
reference to the time ``when the vehicle driveline is engaged in
reverse''. NHTSA agrees that the point in time in which the vehicle's
transmission is engaged in reverse gear is the most logical point in
time from which to orient the image response time criterion.
    Also in regard to image response time, NHTSA acknowledges that
liquid crystal displays require some warm-up time before an image can
be displayed clearly. In-dash LCD displays that are used for multiple
functions are typically already active before the driver shifts into
reverse gear and therefore are already warm and able to display a
rearview video image immediately upon shifting into reverse. However,
in-mirror LCD displays remain off until reverse gear is selected and,
therefore, require some warm-up time before a clear rearview video
image can be displayed. Therefore, some requirement for additional
image response time is inherent in the use of in-mirror LCD displays,
but is avoided with in-dash displays. Conversely, given that the
buildup of heat can also be an issue with in-mirror LCD displays due to
the limited area within the mirror in which heat may dissipate,
providing power to these displays at all times as a means of avoiding
longer image response times is not feasible. Therefore, providing some
allowance of time for an in-mirror LCD display to warm-up may be
reasonable.
    Somewhat related to system the issue of system response time was a
comment from the Advocates for Highway and Auto Safety that suggested
vehicles be equipped with an interlock feature that prohibits it from
being able to move in reverse, even after the transmission has been
placed in reverse gear, until a short period after the countermeasure
system becomes fully operational. This sort of measure would ensure
that drivers had all available information about the presence of any
rear obstacles at the moment that backing began. While this idea
appears to have merit, NHTSA is concerned that drivers that are parking
or hitching a trailer may be annoyed by such a feature. NHTSA seeks
comment on whether this feature might be acceptable to consumers and
whether any substantial advantage of this feature over the use of a
maximum response time specification exists. Based on the comments, the
agency will consider whether to include this feature in the final rule.
ii. Rearview Image Linger Time
    Image linger time is another issue that was raised in the ANPRM.