Linger time refers to the period in which a rearview image continues to
be displayed after the vehicle's transmission has been shifted out of
reverse gear. As noted by some commenters, a period of linger time may
be desirable for situations where frequent transitions from reverse to
forward gear are needed to adjust a vehicle's position (e.g., parallel
parking and hitching). In the ANPRM, NHTSA indicated that a minimum of
4 seconds but not more than 8 seconds of linger time may be appropriate
after the vehicle is shifted from the reverse

position. NHTSA is concerned that excessive linger time may provide a
source of distraction to the driver by a video image that is displayed
longer than is needed. Consumers Union concurred with NHTSA's
recommendation of 4-8 seconds for linger time. Nissan stated that its
systems currently exhibit a linger time of approximately 200
milliseconds and that it does not see value in allowing a longer linger
time. 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 reaches a speed of 5 mph (8 kph). GM
noted that a time-based linger time would be less costly to implement
than a speed-based linger time would. 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).
    Because an excessive image linger time could result in adverse
safety consequences associated with potential driver distraction when
the vehicle is moving forward, NHTSA believes that linger time should
be limited. On the other hand, NHTSA agrees with commenters who noted
that allowing a reasonable linger time would provide a benefit to
drivers who are parallel parking or hitching a trailer. Therefore, we
believe there is a need to specify a maximum, but not a minimum, image
linger time value for presentation of a rearview image.
iii. Rear Visibility System Visual Display Brightness
    In the ANPRM, NHTSA suggested that it is appropriate to adopt a
minimum visual display luminance to ensure that a rearview image is
displayed with sufficient brightness to be adequately visible in
varying conditions, such as bright sunlight or low levels of ambient
light. Adequately visible, in this case, would mean that a driver can
discern the presence of obstacles in the rearview video image. We note
that in the SCI sample, 95 percent of backovers took place in daylight
hours. Therefore a rearview image should be bright enough to be visible
in daylight conditions. Commenters noted that a minimum of 500 cd/m\2\
is appropriate based upon research performed by vehicle manufacturers
and that internal specifications routinely require a luminance of at
least this value. During the agency's review of existing rearview video
systems, we found the display brightness of the existing systems to be
adequate such that visual information was discernible under varying
ambient conditions, such as background light level. While we do not
currently have reason to believe that vehicle manufacturers are
installing rearview video systems with displays having brightness
values less than 500 cd/m\2\, we believe it is necessary to propose an
appropriate minimum brightness so that drivers can see the image under
varying ambient lighting conditions.
iv. Rear Visibility System Malfunction Indicator
    In the ANPRM, NHTSA indicated our belief that no malfunction
indicator would be necessary for a system that presents a visual image
of the area behind the vehicle since the absence of an image would
clearly indicate a malfunction condition. Multiple commenters agreed
with NHTSA's suggestion that such a malfunction indicator is not
necessary for a system presenting a rearview image. We agree with these
comments.

H. Rear Visibility System Compliance Test

    A majority of comments regarding a rear visibility system
compliance test related to ambient lighting conditions during test and
the specific test object used. Comments regarding these issues and
NHTSA's analysis of them follow.
i. Compliance Test Ambient Light Level
    Given that ambient lighting conditions can affect how well a driver
is able to see an in-vehicle visual display, the ANPRM solicited input
regarding what ambient lighting conditions may be most appropriate for
rear visibility system compliance testing. GM recommended that testing
be conducted in 3 lux conditions, or the level provided in dark ambient
conditions with the reverse lights operating. Sony suggested that the
external ambient light level for testing should be 5 lux with reverse
gear and lamps engaged. The AORC stated that tests should be conducted
in a ``min/max illumination condition which best simulates daytime
conditions since the field data indicates this is the accident
condition present and will allow the best value solution to be used.''
Given that 55 of the 58 SCI backover cases occurred in daylight
conditions, NHTSA tends to concur with the AORC's comment on this
matter. We believe that for the purpose of preventing backover crashes
a worst case, ``nighttime'' ambient lighting condition for system
compliance testing may be an unnecessarily challenging requirement.
ii. Compliance Test Object
    NHTSA received many comments regarding specifications for a
compliance test object. Certain features of the test object, most
significantly the height, could have substantial ramifications on the
burdens of compliance. Similarly, the shape and material composition of
the test object would have had significant ramifications for
manufacturers using sensors as a means of compliance. However, given
that NHTSA is proposing a performance requirement that would most
likely be met through the use of rearview video systems, the specific
characteristics of the test object may not have as great of an impact
on countermeasure performance (with the possible exception of the
height and width of the test object). Nonetheless, we have summarized
and addressed the comments on this subject below.
    The ANPRM indicated NHTSA's belief, based on real world data, that
the test object should simulate the physical characteristics of a
toddler. Specifically in the ANPRM and again in this document, we have
stated that 26 percent of victims in passenger vehicle backover crashes
are 1 year old or younger. To date, NHTSA has generally used the
average height of a 12-month-old child to represent a ``1-year-old
child'' size to evaluate technologies that could be used to mitigate
backover crashes. However, looking at the first 58 SCI cases shows that
the average age of the 21 victims aged 1 year or younger was 15
months.\63\ In their comments in response to the ANPRM, the AAM and GM
recommended that the target dimensions be based on an 18-month-old
child to best represent the victims involved in the first 56 documented
SCI backover crash cases. Anthropometric data published by the CDC
shows that the height difference between an average 15-month-old child
and an average 18-month-old child is approximately 1 inch.\64\ The
difference in shoulder breadth for these two ages is approximately 0.2
inches. Upon further consideration of the SCI data regarding the age of
victims, the fact that the small difference in size between a 15-month-
old and 18-month-old child,

and the rationale provided by commenters, NHTSA agrees with the idea of
basing the test object dimensions representing an average 12- to 23-
month-old child using a midpoint age value of 18 months.
---------------------------------------------------------------------------

    \63\ This apparent disparity is explained by the fact that the
category ``1-year-old child'' encompassed all children under age 2.
Therefore, the average age of those children, some of whom were
almost 2, and some younger than 12 months comes out to 15 months.
    \64\ CDC, Clinical Growth Charts. Birth to 36 months: Boys;
Length-for-age and Weight-for-age percentiles. Published May 30,
2000 (modified 4/20/2001) CDC, Clinical Growth Charts. Birth to 36
months: Girls; Length-for-age and Weight-for-age percentiles.
Published May 30, 2000 (modified 4/20/2001).
---------------------------------------------------------------------------

    In the ANPRM, NHTSA suggested specific test object dimensions that
correspond to a 12-month-old child. In regard to the height of the test
object, NHTSA suggested in the ANPRM some specific test object
dimensions that correspond to a 12-month-old child, including a height
of 30 inches (0.762 meters). As stated earlier, the average height of a
``1-year-old'' child was used in NHTSA testing since SCI data have
indicated that 26 percent of victims are 1 year of age or younger. In
response to the height value suggested in the ANPRM, the AAM and GM
recommended alternative heights. Specifically, GM recommended a test
object height of 32 inches (81 cm). The AAM recommended specific test
object dimensions of 82 cm (32.28 in) height based on 2000 CDC data for
an 18-month-old child.\65\ NHTSA believes that the difference between
30, 32, and 32.28 to be minimal for this purpose and in the proposal
offers a compromise amongst these values.
---------------------------------------------------------------------------

    \65\ CDC, Clinical Growth Charts. Birth to 36 months: Boys;
Length-for-age and Weight-for-age percentiles. Published May 30,
2000 (modified 4/20/2001) CDC, Clinical Growth Charts. Birth to 36
months: Girls; Length-for-age and Weight-for-age percentiles.
Published May 30, 2000 (modified 4/20/2001).
---------------------------------------------------------------------------

    In regard to test object width, NHTSA suggested a value of 5 inches
to represent the breadth of an average child's head. In response to the
suggested value, the AAM recommended an alternative test object width
of 15 cm (5.9 in.) based on 2000 CDC data for an 18-month-old
child.\66\ NHTSA agrees and has reconsidered the size of test object
needed to adequately assess system performance.
---------------------------------------------------------------------------

    \66\ CDC, Clinical Growth Charts. Birth to 36 months: Boys;
Length-for-age and Weight-for-age percentiles. Published May 30,
2000 (modified 4/20/2001) CDC, Clinical Growth Charts. Birth to 36
months: Girls; Length-for-age and Weight-for-age percentiles.
Published May 30, 2000 (modified 4/20/2001)
---------------------------------------------------------------------------

    NHTSA's test data to date demonstrate that, except at the edges of
the image and immediately aft of the rear bumper (i.e., within 1 foot),
a rearview video system generally displays the entire body of the child
when present within the video camera's field of view. Since the entire
body of a child standing behind the vehicle is visible with a rearview
video system, the agency now believes that the test object's width
should represent the width of the child's entire body, rather than just
the child's head. While the average shoulder breadth of a standing 18-
month-old child with their arms at their sides is approximately 8.5
inches, the absolute, overall width of an 18-month-old child standing
with arms relaxed approaches 12 inches. A 12-inch test object width is
currently used to represent a small child in the school bus mirror test
defined under paragraph S13 of FMVSS No. 111. Furthermore, in order to
perform compliance testing in regard to visual display image quality,
the test object must be large enough that when displayed at substantial
longitudinal range behind the vehicle the object is still large enough
to be measured across its smallest dimension with some accuracy and
minimal obscuration due to image graininess (for an electronic
display).

V. NHTSA Research Subsequent to the ANPRM

    As detailed in the ANPRM, NHTSA had conducted research to assess
drivers' ability to avoid backing crashes in a controlled test
involving presentation of an unexpected obstacle behind the vehicle
while the driver backed out of a garage. Possible countermeasure
technologies assessed in this research included a rearview video system
with a 7.8-inch (measured diagonally) visual display in the center
console, rearview video with a 7.8-inch in-dash visual display
augmented by a separate rear parking system, and a baseline (or control
group) condition in which no system was present.
    The results of this research, which were presented in detail in the
ANPRM, showed that drivers avoided 42 percent of crashes when a
rearview video system was present and only 15 percent of crashes when
both rearview video and rear object detection sensors were present on
the vehicle. Without a system, all participants crashed.
    While the results provided useful information regarding the
potential of available technologies to aid drivers in avoiding backing
crashes with unexpected obstacles, the study did not address the
additional technologies being considered as a means of improving rear
visibility per the Act. As a result, additional research was undertaken
after publication of the ANPRM to assess drivers' ability to use a rear
parking sensor system (alone), a rear-mounted convex ``look-down''
mirror, and rear-mounted cross-view mirrors. In addition, to assess
whether display location for a rearview video system may affect
drivers' performance in avoiding backing crashes using the system,
drivers were also tested using rearview video systems with two sizes of
in-mirror visual displays (2.4 inch and 3.5 inch). Finally, research
aimed at investigating the effect of test location on results was also
completed. All the research results that NHTSA has collected to date
are available on the NHTSA Web site and in Docket No. NHTSA-2009-0041.
A complete summary of NHTSA's research on rear visibility
countermeasure technologies is presented in Section VI.

A. Rearview Video Systems With In-Mirror Visual Displays

    Two rearview video system conditions were assessed: one having a
2.4-inch visual display and another with a 3.5-inch visual display.
These tests used the same 2007 Honda Odyssey that was used in the
previous rearview video system test, and the drivers in the tests were
all drivers who personally owned a 2008 Honda Odyssey with a rearview
video system with visual display (original equipment, 2.4 inch)
integrated in the interior rearview mirror, to make sure that
unfamiliarity with such a system was not a factor. The numbers of test
participants run were 12 for the 2.4-inch display and 10 for the 3.5-
inch display. The test results showed very different results between
the two visual display sizes. Thirty-three percent of subjects driving
vehicles equipped with a rearview video system with 2.4-inch visual
display avoided crashing into the obstacle. However, 70 percent of
subjects driving vehicles equipped with a rearview video system with
3.5-inch visual display avoided a crash. However, despite the observed
37 percent more crashes avoided with the larger in-mirror display, the
result was not found to be statistically significant due to the
relatively small sample size of subjects tested.\67\ Across all system
conditions tested, the rearview video system with 3.5-inch visual
display proved to be the one with which drivers avoided the most
crashes.
---------------------------------------------------------------------------

    \67\ In2010, NHTSA intends to conduct additional trials of this
experiment to obtain more data in an effort to attain statistical
significance.
---------------------------------------------------------------------------

B. Rear-Mounted Convex Mirrors

    A similar test was conducted with rear-mounted convex ``look down''
mirrors and rear cross-view mirrors. These tests also used the 2007
Honda Odyssey and were conducted using owners of this type of vehicle.
Since no vehicle sold in the U.S. is known to offer rear convex look-
down mirrors as original equipment, an aftermarket mirror was used. To
provide the test participants in this system condition with some
experience using the mirror (before they were presented with the

unexpected obstacle event), the mirrors were installed on their
vehicles for 4 weeks prior to the test event.\68\ During the test
procedure, none of the thirteen participants that participated in the
study successfully avoided the unexpected obstacle, giving a driver
performance factor of zero.
---------------------------------------------------------------------------

    \68\ In order to conceal the fact that this was an experiment in
rear obstacle detection, participants were told that recording
devices were installed in the rear mirror.
---------------------------------------------------------------------------

    A similar test was conducted with rear cross-view mirrors. This
test condition involved use of a 2003 Toyota 4Runner, which is the only
vehicle sold in the U.S. known to offer rear convex cross-view mirrors
as original equipment. Test subjects were owners of a 2003-2007 Toyota
4Runner who had owned and driven the vehicle for at least 6 months.
During the test procedure, none of the seven participants that
participated in the study successfully avoided the unexpected obstacle,
giving the rear cross-view mirror system a driver performance factor of
zero.

C. Rear Sensor Systems

    Using the same unexpected obstacle event scenario, NHTSA tested
fourteen drivers of vehicles equipped with a rear parking sensor
system. This system involved use of a 2009 Ford Flex with an original
equipment rear parking aid system using ultrasonic sensors. As with the
testing of the other system types, drivers of the Ford Flex with
sensor-based rear parking aid system were persons who owned the vehicle
and had driven it as their primary vehicle for at least 6 months, so
that they would be familiar with the system. During the test, the
parking aid system on this vehicle detected the plastic obstacle and
produced an auditory warning in 100 percent of trials. This detection
rate was significantly better than the 39 percent detection rate
observed in the NHTSA's prior testing that used an identical scenario
but a different test vehicle.\69\ Despite the consistent rate of object
detection demonstrated by the Ford Flex rear parking sensors, only one
test subject in this system condition successfully avoided crashing
into the obstacle, resulting in only 7 percent of crashes avoided.
However, we note that all of the participants braked slightly, and four
came to a momentary, complete stop before resuming rearward motion and
crashing into the obstacle.
---------------------------------------------------------------------------

    \69\ Mazzae, E.N., Barickman, F.S., Baldwin, G. H.S., and
Ranney, T.A. (2008). On-Road Study of Drivers' Use of Rearview Video
Systems (ORSDURVS). National Highway Traffic Safety Administration,
DOT 811 024.
---------------------------------------------------------------------------

D. Ability of Currently Available Sensor Technology To Detect Small
Child Pedestrians

    NHTSA's 2009 continuation of research to examine drivers' ability
to avoid backing crashes used a 2009 Ford Flex equipped with a rear
parking system. As noted in Section C above, this vehicle exhibited a
100-percent detection rate for the plastic obstacle used in the final
conflict scenario. Given the improved detection performance seen with
this ultrasonic-based sensor system over prior testing results using
other ultrasonic systems, NHTSA thought it appropriate to assess this
system's ability to detect small children.
    Using a protocol developed previously and documented,\70\ NHTSA
conducted static and dynamic tests using young children and recorded
the sensor system's ability to detect the children. Testing was
conducted with two 1-year-old children and four children aged
approximately 3 years. Tests with 1-year-old children included
standing, walking laterally, and riding a wheeled toy that was towed
(by test staff) laterally behind the vehicle. Tests with the 3-year-old
children included standing, walking laterally, running laterally, and
riding a wheeled ride-on toy behind the vehicle.
---------------------------------------------------------------------------

    \70\ Mazzae, E.N. and Garrott, W.R., Experimental Evaluation of
the Performance of Available Backover Prevention Technologies, NHTSA
Technical Report No. DOT HS 810 634, September 2006, and Vehicle
Backover Avoidance Technology Study, Report to Congress, November
2006.
    .
---------------------------------------------------------------------------

    Testing showed that the 1-year-old children were detected in 100
percent of trials at a range of 1, 2, or 3 feet behind the vehicle when
walking or riding on the wheeled toy. At a range of 4 feet, the 1-year-
old children were detected in 4 of 6 trials (67 percent) when walking,
but were not detecting at 4-foot range when riding the wheeled toy.
    The 3-year-old children were found to be detected out to a range of
6 feet. Table 8 below summarizes the results for these tests and shows
strong detection performance out to a range of 3 feet, as was seen for
the younger children. However, detection performance appears to decline
significantly at the 4-foot range.

Table 8--2009 Ford Flex Rear Sensor System Detection Performance With 3-
                            Year-Old Children
------------------------------------------------------------------------
                                             Walking   Running   Ride-on
 Longitudinal range from rear bumper face      (%)       (%)     toy (%)
------------------------------------------------------------------------
1 ft......................................       100       100       100
2 ft......................................       100       100       100
3 ft......................................       100        67        87
4 ft......................................        40        13        47
5 ft......................................        20         0         0
6 ft......................................        20         0         0
------------------------------------------------------------------------

    These tests demonstrated improved consistency of detection over
results from past NHTSA testing of ultrasonic-based sensor systems.
However, the short detection range for young children is insufficient
for the purposes of backover mitigation. NHTSA notes, however, that as
with research results described in the ANPRM, all systems tested were
designed as parking aids and were not intended to be used for the
purpose of detecting children.

VI. Countermeasure Effectiveness Estimation Based on NHTSA Research
Data

    Three conditions must be met for a rear visibility technology to
provide a benefit to the driver. First, the crash must be one that is
``avoidable'' through use of the device; i.e., the pedestrian must be
within the target range for the sensor, or the viewable area of the
camera or mirror. Second, once the pedestrian is within the system's
range, the device must ``sense'' that fact, i.e., provide the driver
with information about the presence and location of the pedestrian.
Third, there must be sufficient ``driver response,'' i.e., before
impact with the pedestrian, the driver must receive this information
and respond appropriately by confirming whether someone is or is not
behind the vehicle before proceeding. These factors are denoted as
fA, fS, and fDR, respectively, in this
analysis. Their product is the final system effectiveness.
    This three-phase concept is depicted in Figure 3 below for both
sensor-based systems and visual systems (i.e., rearview video systems,
mirrors).
BILLING CODE 4910-59-P

[GRAPHIC] [TIFF OMITTED] TP07DE10.009

BILLING CODE 4910-59-C
    Based on this general description of the process of avoiding a
backing crash, NHTSA has developed overall effectiveness of various
backover countermeasure technologies using three individual factors.
First, SCI backover incident reports were examined to characterize the
geometry of the specific situations in which a backing vehicle struck a
pedestrian or cyclist to determine if the backover

crash was conceivably avoidable using a given technology and standard
vehicle equipment (i.e., required rearview mirrors). We call this the
``avoidability'' of the backing conflict situation, or factor
``FA'' depicted in the figure above. Second, we estimated
the probability that a countermeasure could sense and warn the driver
of the rear obstacle, which we call ``system performance,'' or factor
``FS'' in the figure above. Finally, we determined the
likelihood of a driver responding appropriately to information provided
by the system to successfully avoid a backing crash. We call this
``driver reaction,'' depicted above as factor ``FDR.'' If an
obstruction in the path of a backing vehicle is avoidable, detectable,
and a driver reacts appropriately, a backover crash will be avoided.
Therefore, the ``overall effectiveness'' of the system is calculated by
multiplying FA, FS, and FDR together.
The derivation of these three factors is described below.

A. Situation Avoidability

    Factor ``FA'' was derived by determining the
``avoidability'' of a backover crash. In order to better understand how
avoidable these situations are, NHTSA closely reviewed the SCI backover
case reports. By qualitatively analyzing the case reports, NHTSA
assessed a variety of factors concerning the case and how they
contributed to ``avoidability'', including:
     Original and final position of the vehicle.
     Vehicle speed.
     If the victim was conceivably visible through direct
vision or indirectly using the vehicle's mirrors given the visual
aspects of the environment surrounding the vehicle during the backing
maneuver (i.e., was the area clear of visual obstructions?).
     Position of the victim with respect to the vehicle.
     Size, orientation (i.e., standing, sitting), and movement
of the victim.
     If the victim was detectable given the detection
characteristics of a given technology.
     If the vehicle could have stopped in time given typical
system performance for that technology (based on results of NHTSA
testing of system capabilities).
    NHTSA used a general process to determine if a crash was avoidable.
We examined the system detection zone, vehicle blind zone area, and
visible areas surrounding the vehicle. If the pedestrian or cyclist was
detectable either visually or by a sensor-based system, then what
followed was a cataloguing of all the impediments to a typical,
reasonable driver reacting in time after receiving a warning or
recognizing a pedestrian or cyclist seen on a rearview video system
display.
    While many backover crashes are theoretically avoidable, certain
characteristics render some incidents impossible to prevent using rear
object detection technology, even if the technology and the person
using it act appropriately. Consider, for example, a situation where a
vehicle is backing along a wall. If a child walks through a gap in the
wall and enters the vehicle's path less than 2 feet from the vehicle,
the backover would be judged ``unavoidable.'' This is because no known
technology could have detected the child through the wall, and no car
could brake fast enough to stop in time to avoid the child, once he
became visible.
    Some backover crashes are avoidable for certain technologies, but
not for others, a function that generally corresponds to the detection
range of the rear visibility countermeasure. For example, an ultrasonic
sensor might have an effective range of only 6 feet, while a rearview
video system might be able to effectively display a child positioned 20
feet behind a vehicle. If a vehicle were backing at a relatively high
speed toward a child, it might take 10 feet once the brakes were
applied to stop the vehicle. In that case, the backover crash would be
unavoidable for the vehicle equipped with the sensor system, because it
could have only detected the child at 6 feet. On the other hand, the
same backover situation would be considered an ``avoidable'' incident
for a vehicle equipped with the rearview video system. This is why the
``FA'' factor differs for different technologies.
    We note, of course, that merely because a backover crash is
avoidable does not mean it will be avoided. Furthermore, drivers differ
in their tendencies to check rearview mirrors and rearview video system
displays, and may not always react perfectly and with sufficiently fast
reaction time. However, those factors are addressed in the two sections
below. The avoidability of a situation merely describes whether
backover avoidance technology could have had any effect at all on the
outcome of the conflict situation.
    Based on our analysis of the SCI data, we have derived the
following values for the percent of backover crashes that are avoidable
using various technologies. Rear-mounted mirrors could prevent up to 49
percent of backover crashes. Sensor technology, on average, could have
prevented up to 52 percent of backover crashes. For a rearview video
system, NHTSA's analysis concluded that up to 76 percent of backover
crashes were avoidance with a 130-degree camera lens and 90 percent of
backover crashes were avoidable with a 180-degree camera lens, through
which more pedestrians could be seen approaching from the sides of the
vehicle.

B. System Performance

    Factor ``FS'' was derived by determining the ability of
the system to detect or display a rear obstacle based on the results of
comprehensive NHTSA testing of systems' ability to detect various
objects in a laboratory setting. Since mirrors and rearview video
systems have the ability to display anything within their field of
view, we used a figure of 100 percent effectiveness.\71\ Sensors,
however, may not always detect an obstacle behind the vehicle, even
when the object is within their specified detection zone. This may be
the result of the reflectivity of the obstacle, such as if a child's
clothing is textured and therefore absorbs the ultrasonic signal. Our
specific value for sensor system performance is based on research
described at length in the ANPRM. In NHTSA's 2007 study of drivers'
ability to avoid a backing crash with an unexpected obstacle while
driving a vehicle equipped with a rearview video system either alone or
in conjunction with a rear parking system, the sensor-based system
detected the rear obstacle in 39 percent of test trials.\72\ This value
represents the system performance of sensor-based systems in the
calculation of overall effectiveness presented in this notice.
---------------------------------------------------------------------------

    \71\ While we realize a component of a rearview video system
could malfunction or break or a mirror could break or be misaligned,
for purposes of our analysis, we assume they, and sensors, are
functioning properly.
    \72\ Mazzae, E.N., Barickman, F.S., Baldwin, G.H. S., and
Ranney, T.A. (2008). On-Road Study of Drivers' Use of Rearview Video
Systems (ORSDURVS). National Highway Traffic Safety Administration,
DOT 811 024.
---------------------------------------------------------------------------

C. Driver Performance

    Factor FDR represents the degree to which drivers may
use the various possible backover avoidance countermeasures to
successfully avoid a crash. Unlike many other safety technologies,
these countermeasures are only effective at preventing vehicle crashes
if they are understood, trusted, and used by drivers. This is a
particularly important issue considered in this rulemaking. Currently,
drivers are most familiar with the interior and side rearview mirrors
required or permitted by FMVSS No. 111. Signals from sensor-based rear
object detection systems and images from new mirrors and rearview video
system visual

displays must be noticed, understood, and reacted to by the driver in
order to avoid a crash. A system merely detecting or displaying the
obstacle in the path of the vehicle is not enough to avoid a crash.
    NHTSA has differing concerns related to all three types of
technologies currently available for informing a driver of the presence
of an obstacle behind a vehicle. With regard to rear-mounted convex
mirrors, the primary concern is that the images they provide are too
distorted to permit the driver to discern an obstacle within the image.
In addition, the range that mirrors display behind the vehicle may be
insufficient to allow a driver time to brake to a stop once the driver
sees the rear obstacle. With all sensors, drivers may tend to not trust
the warnings provided because they may not be able to visually confirm
that an obstacle is present in the vehicle's rear blind zone. In
addition, if a system is prone to frequent false positive signals, this
may cause drivers to ignore, or even turn off, the system, a concern
echoed by several commenters. Finally, we are concerned that drivers
may have difficulty integrating glances at a rearview video system
visual display into their normal glance patterns while backing,
focusing more on direct view (glancing rearward over their shoulder) or
existing mirrors. In this section, we present the driver performance
research that NHTSA has conducted and continues to conduct on currently
available system types that are relevant to backover avoidance.
    As described in the ANPRM and in Section V of this notice, NHTSA
conducted research \73\ to assess drivers' ability to avoid backing
crashes in a controlled test involving presentation of an unexpected
obstacle behind the vehicle while the driver backed out of a garage.
The tests were designed so that the crash was always preventable (i.e.,
an ``FA'' factor of 100%) for drivers of vehicles equipped
with a countermeasure system. Drivers in the baseline condition whose
vehicles were only equipped with standard rearview mirrors could not
see the rear obstacle and therefore it was nearly impossible for them
to avoid a crash (and none did). The tests were also designed such that
the obstruction was detectable by the countermeasure \74\ in every
trial (i.e., a ``FS'' factor of 100%). Therefore, any
failure of the driver to avoid crashing into the obstacle should be
attributable solely to the driver performance factor.\75\ Therefore,
NHTSA believes that these experiments isolated, to the extent possible,
the effects of driver performance in avoiding a backing crash.
---------------------------------------------------------------------------

    \73\ Mazzae, E.N., Barickman, F.S., Baldwin, G.H.S., and Ranney,
T.A. (2008). On-Road Study of Drivers' Use of Rearview Video Systems
(ORSDURVS). National Highway Traffic Safety Administration, DOT 811
024.
    \74\ This means that the obstacle's image either appeared on the
mirror surface, was visible on a rearview video system visual
display. For sensors, the obstacle as positioned at the centerline
of the vehicle was assumed to be detectable by the system.
    \75\ However, the ultrasonic sensor-based system used in this
testing was found to only detect the centered obstacle in 39 percent
of trials.
---------------------------------------------------------------------------

    Table 9 summarizes the comparative driver effectiveness results for
each of the seven systems assessed. This is how the various
``FDR'' factor figures were derived, which are used in the
overall effectiveness calculations, described below.

                  Table 9--Summary of Crash Results in Unexpected Obstacle Event by System Type
----------------------------------------------------------------------------------------------------------------
                                                                                Driver
                                                                                Number of      performance
                           Technology                                    N            crashes        (``FDR''
                                                                                factor) (%)
----------------------------------------------------------------------------------------------------------------
No system.......................................................              12              12               0
Rear-mounted convex mirrors.....................................              13              13               0
Rear cross-view mirrors.........................................               7               7               0
Sensors (ultrasonic and radar) \76\.............................              14              13               7
Rearview video, in-dash, combined with ultrasonic sensors.......              13              11              15
Rearview video, in-mirror, 2.4-inch display.....................              12               8              33
Rearview video, in-mirror, 3.5-inch display.....................              10               3              70
Rearview video, in-dash.........................................              12               7              42
----------------------------------------------------------------------------------------------------------------

    NHTSA\76\ has recently completed the third in a series of three
studies that examined drivers' use of backing aid systems to avoid
crashes while backing. Backing aid systems examined in the studies
included rearview video (RV) systems with different display sizes and
locations, rear sensor-based systems (RPS), and a combination system
having both rearview video and rear sensors. For the five ``system''
conditions examined in both laboratory (studies 1 and 2) and non-
laboratory (study 3, daycare parking lot) settings, the relative crash
rates were consistent. Given this observation, once our reduction of
the data is complete, we will place these results in the docket and
incorporate them for the final rule.
---------------------------------------------------------------------------

    \76\ A radar-based sensor system was not assessed in this test,
however, for the purposes of assessing driver performance, sensor
technology was deemed not critical in this research.
---------------------------------------------------------------------------

D. Determining Overall Effectiveness

    Based on the above strategy of defining the components of
effectiveness, we can estimate the overall effectiveness of each of the
possible backover avoidance countermeasures examined. Overall, NHTSA's
research showed that out of all technologies tested, rearview video
systems were the most effective in aiding drivers to avoid backing
crashes. With rear-mounted convex mirrors, the research showed that
drivers were not inclined to use them in backing situations, presumably
due to image distortion and limited range. While sensors may have the
potential to show benefits, the research demonstrated that without
visual confirmation, drivers tended not to believe the warnings
provided by the sensor system, and continued the backing maneuver in
spite of the warning. The agency requests comments on what steps could
be taken and at what cost and with what consequences to improve the
range and sampling rate of sensors, to address problems with detecting
pedestrians wearing low reflectivity clothing and to improve driver
response to sensor provided warnings. What sort of performance
requirement would be needed to ensure that sampling frequency would be
increased sufficiently? However, rearview video systems examined were
able to consistently display the rear obstacles to the drivers, as well
as enable and induce

drivers to avoid them. Table 10 below summarizes these results.

                        Table 10--Summary of Overall Effectiveness Values by System Type
----------------------------------------------------------------------------------------------------------------
                                                                                Final effectiveness
                          System                              FA(%)     FS(%)    FDR(%)    (%)  FA x FS x FDR =
                                                                                FE
----------------------------------------------------------------------------------------------------------------
180[deg] Camera...........................................        90       100        55                    49
130[deg] Camera...........................................        76       100        55                    42
Ultrasonic................................................        49        70         7                     2.5
Radar.....................................................        54        70         7                     2.7
Mirrors...................................................      * 33       100      ** 0                     0
----------------------------------------------------------------------------------------------------------------
* FA for mirrors is taken from separate source due to lack of inclusion in the SCI case review that generated FA
  for cameras and sensors.
** FDR for mirrors is taken from a small sample size of 20 tests. It is 0% because throughout testing, drivers
  did not take advantage of either cross-view or lookdown mirrors to avoid the obstacle in the test.

VII. Proposal To Mandate Improved Rear Visibility

    Based on the comments on the ANPRM and NHTSA's research on the
various means available to mitigate backover crashes, NHTSA has
developed the following proposal to improve light vehicle rear
visibility. The proposal is based in part on our tentative conclusion
that drivers need to be able to see a visual image of a 32-inch tall
cylinder with 12-inch diameter behind the vehicle over an area 5 feet
to either side of the vehicle centerline by 20 feet in longitudinal
range from the vehicle's rear bumper face. We are also proposing to
specify certain performance criteria for visual display performance,
such as luminance and rearview image response time, which are detailed
below, as well as durability requirements. We believe that these
specifications are necessary to ensure robust and effective
performance.
    These proposed improvements would apply to all passenger cars,
MPVs, trucks, buses, and low-speed vehicles with a GVWR of 10,000
pounds or less. Based on the substantial numbers of fatalities and
injuries involving light vehicles other than LTVs, we are not proposing
to limit these more stringent rear visibility performance requirements
to LTVs only. Further, despite NHTSA's decision to propose a
requirement for improved rear visibility for nearly all light vehicles,
we have included in the preliminary regulatory impact analysis an
economic analysis of an alternative in which only LTVs are subjected to
these requirements. We invite comments on this additional analysis.
    In the near term, we believe that existing rearview video systems
can be used to meet the requirements with minimal or no modifications.
While we recognize that there are significant costs involved in
addressing the safety problem at issue using rearview video systems, we
believe that our research shows that rearview video systems currently
represent the most effective technology to address the problem of
backover crashes. This is because rear-mounted convex mirrors and
sensor-based object detection systems offer few benefits compared to
rearview video systems due to system performance and driver use issues.
As we have previously said, use of a blind zone area threshold to focus
the improve visibility requirements on vehicles with large rear blind
zone areas, and presumably high backover crash rates, from these
enhanced rear visibility requirements lacks a sufficient statistical
basis while adding problematic issues. Some vehicles with comparatively
small blind zones had high rates of backover incidents. Similarly,
limiting countermeasures to LTVs, such as vans, multipurpose passenger
vehicles, and trucks with a GVWR of 10,000 pounds or less, would leave
large gaps in safety protection as well as a disparity in quality of
rear visibility between these vehicles and passenger cars.
    In response to the suggestion of many commenters that, regardless
of how broadly or narrowly the performance requirements are applied
within the population of light vehicles, the requirements be
technology-neutral, we believe we need to consider the practical
consequences that adopting a technology neutral approach would have not
only for the first phase of a backover crash, but also for each of the
later phases. Adequate performance at the initial phase does not
necessarily assure adequate performance at a later phase. The ultimate
safety test of a technology in the context of this rulemaking is
whether the technology enables the driver to detect the presence of a
pedestrian in or near the path of the driver's backing vehicle and
whether drivers use the technology and succeed in avoiding backover
crashes.
    Under our proposal, current rear object detection sensors and rear-
mounted convex mirrors would not be sufficient as stand-alone
technologies to meet the proposed rear visibility requirement. This is
because sensors and mirrors, while able to detect pedestrians to some
degree, simply do not induce the driver response needed to prevent
backover crashes. NHTSA research indicates that the presence of a
system consisting of rear-mounted convex mirrors was statistically
equivalent to the absence of any system at all for seeing pedestrians
behind a driver's vehicle. Therefore, we do not believe that any
benefits would accrue from installation of rear-mounted convex mirrors.
    With regard to sensors, our research shows \77\ that, in the vast
majority of cases, a sensor-activated warning of the presence of an
obstacle will not lead to a successful (i.e., timely and sufficient)
crash avoidance response from the driver unless the driver is also
provided with visual confirmation of obstacle presence. Because of this
apparent need for visual confirmation and that the fact that sensors
induced a successful driver reaction only 7 percent of the time in
NHTSA testing, we do not believe it is in the best interest of safety
to propose allowing systems that rely on sensors alone.
---------------------------------------------------------------------------

    \77\ Research by GM also showed this apparent tendency of
drivers to want visual confirmation of obstacle presence.
---------------------------------------------------------------------------

    However, we note that we are not proposing to disallow sensor
systems as a supplement to rearview video systems. While NHTSA
research\78\ showed 27 percent worse driver crash avoidance performance
in a vehicle equipped with both a rearview video system and rear
sensors than in a vehicle with only rearview video, deficiencies in the
performance of the sensor system may have confounded the isolation of
driver performance. It is thus unclear to what extent the presence of
sensors may

induce some drivers to rely on the sensors to some extent instead of
relying exclusively on close and uninterrupted monitoring of the video
display. To the extent that drivers rely on sensors and to the extent
that the sensors fail to detect objects, driver crash avoidance
performance will worsen. We seek comment on this issue. Furthermore,
the cost of a combined rearview video and sensor system would be higher
than that of a rearview video system alone.
---------------------------------------------------------------------------

    \78\ Mazzae, E.N., Barickman, F.S., Baldwin, G.H.S., and Ranney,
T.A. (2008). On-Road Study of Drivers' Use of Rearview Video Systems
(ORSDURVS). National Highway Traffic Safety Administration, DOT 811
024.
---------------------------------------------------------------------------

    Finally, while NHTSA is not at this time proposing to mandate
advanced multi-technology countermeasure systems, we note that research
continues. These systems may include video-based systems with real-time
image processing for object detection and combinations of sensors and
video cameras, some of which (detailed by commenters) include sensor-
based graphic overlays superimposed over visual images from rearview
video systems. Advances like infrared detection, automated braking, and
backing speed limitation were all concepts raised either by commenters
or NHTSA analysis.

A. Proposed Specifications

    Our general approach in developing performance requirements was to
consider the various phases of backover crashes and identify key areas
of performance pertinent to overall system effectiveness. In the
absence of existing consensus industry standards, we reviewed existing
systems and determined which aspects of performance should be addressed
in the regulatory text of this proposal. Based on the systems we have
tested and comments on the ANPRM, we believe that existing systems
generally meet our proposed specifications and in cases in which they
do not, changes could be made with minimal cost impact. For example, it
is likely that existing systems would meet our durability requirements
because they are typically subjected to vehicle level tests involving
harsher conditions than we are proposing. Both vehicle and equipment
manufacturers cited low warranty claim rates for rearview video systems
in their comments. This indicates to us that today's systems are
proving durable in typical driving conditions. Similarly, while some
current systems would not satisfy our maximum image response time
requirement, a change to the vehicle to prioritize display of the
rearview video image over navigation software would significantly
improve image response time with minimal cost.
i. Improved Rear Field of View
    To determine the appropriate minimum width of the required visible
area, NHTSA reviewed both available SCI backover case data and our
Monte Carlo analysis of backover crash risk as a function of pedestrian
initial location. While some small risk exists as far as 9 feet
laterally to the left and right of a rearward extension of a vehicle's
longitudinal centerline, the vast majority of the risk is concentrated
within a 10-foot wide area that extends symmetrically only 5 feet
laterally to either side from the extended centerline. Accordingly,
NHTSA proposes that the required area of improved visibility be this
10-foot wide area that is centered on the vehicle's centerline.
    To determine the appropriate minimum longitudinal range (i.e.,
length) of the area that should be specified to maximize the
feasibility and effectiveness of the proposal in reducing backover
crashes, NHTSA considered comments on the ANPRM, SCI backover case
data, and the results of our Monte Carlo analysis. Using the 58 SCI
backover cases, NHTSA examined the distance the vehicle traveled prior
to striking the pedestrian. Figure 4 shows the percent of cases
encompassed by various ranges of longitudinal distance. These data show
that in 77 percent of SCI backover cases the vehicle traveled 20 feet
or less before striking the victim. The Monte Carlo analysis of
backover crash risk as a function of the pedestrian's initial location
used a distribution of actual backing maneuver travel distances based
on those observed in naturalistic backing maneuvers made by test
participants in NHTSA's research study that examined drivers' use of
rearview video systems.\79\ The Monte Carlo analysis, which was
outlined in Section II.C.v, indicated based on computer simulation that
the highest risk for pedestrians being struck is within a range of 33
feet aft of the rear bumper. Given that actual backover SCI case data
are available, NHTSA proposes a longitudinal range for rear visibility
coverage of 20 feet extending backward from the rearmost point of the
rear bumper based on those rear-world data.
---------------------------------------------------------------------------

    \79\ Mazzae, E.N., Barickman, F.S., Baldwin, G.H.S., and Ranney,
T.A. (2008). On-Road Study of Drivers' Use of Rearview Video Systems
(ORSDURVS). National Highway Traffic Safety Administration, DOT 811
024.

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

[GRAPHIC] [TIFF OMITTED] TP07DE10.010

    To ensure adequate visibility of this area, the agency is
specifying the placement of seven test objects (cylinders) within the
area. Given the size of the area and the locations of the cylinders
within the area, we believe that a view of the entire area can be
captured through the installation of a single video camera that has a
minimum 130-degree horizontal angle and is located at or near the
centerline of the vehicle. For that reason, NHTSA's analysis has used
the estimated costs and benefits of a rearview video system with a 130-
degree video camera.
ii. Visual Display Requirements
    The following sections describe the proposed requirements for
visual displays used to present images of the area behind a vehicle.
NHTSA believes these requirements are important to achieving reasonable
system effectiveness. Further, we note that one potential concern
expressed to NHTSA is that specifying requirements could increase costs
for display manufacturers by requiring them to conduct expensive
certification tests of equipment. We note that the requirements
proposed today are vehicle requirements, not equipment requirements,
and so we do not believe that equipment manufacturers will be unduly
burdened.
a. Rearview Image Size
    NHTSA is proposing a performance requirement of at least 5 minutes
of arc \80\ for the displayed size (i.e., how large the cylinders
appear) in the rearview image of three test cylinders (cylinders A, B,
and C) that are located 20 feet aft of the rearmost point on the
vehicle's rear bumper. Specifically, we are proposing to require that
when the images of these three test cylinders are measured, the average
size of the three displayed test cylinders must not be less than 5
minutes of arc. Additionally, the displayed size of each of the three
displayed test cylinders individually must not be less than 3 minutes
of arc. NHTSA does not believe that there is a need to propose
displayed size requirements for any of the other test cylinders,
because the three furthest test objects will always appear the
smallest, thus representing the worst case visually observable
condition for the 7 cylinders, and any additional measurements would be
an unnecessary burden.
---------------------------------------------------------------------------

    \80\ A minute of arc is a unit of angular measurement that is
equal to one-sixtieth of a degree.
---------------------------------------------------------------------------

    The reason for proposing 5 minutes of arc for the average displayed
size of the test cylinders is that NHTSA believes this is the minimum
size needed for non-professional drivers to distinguish and react to
images. The 3 and 5 minutes of arc figures are based on research
originally published by Satoh, Yamanaka, Kondoh, Yamashita, Matsuzaki,
and Akisuzuki in 1983.\81\ Satoh et al examined the relationship
between an object's subtended visual angle \82\ at a person's eyes and
a person's subjective ability to see the object and to make judgments
about what he or she is seeing. Satoh asserted that an object must
subtend at least 5 minutes of arc for a person to be able to make
judgments about the object.
---------------------------------------------------------------------------

    \81\ Satoh, H., Yamanaka, A., Kondoh, T., Yamashita, M.,
Matsuzaki, M., and Akisuzuki, K., ``Development of a Periscope
Mirror System,'' JSAE Review, November 1983.
    \82\ The angle which an object or detail subtends at the point
of observation; usually measured in minutes of arc. If the point of
observation is the pupil of a person's eye, the angle is formed by
two rays, one passing through the center of the pupil and touching
the upper edge of the observed object and the other passing though
the center of the pupil and touching the lower edge of the object.
---------------------------------------------------------------------------

    To date, NHTSA has based its requirements for minimum image size
(the minimum subtended visual angle at the driver's eyes) on the Satoh
et al. research. The school bus cross view mirror requirements in FMVSS
No. 111 are based in part on the Satoh

research.\83\ For example, paragraph S9.4 of FMVSS No. 111 requires a
school bus cross-view mirror to show the driver a specified child
surrogate test object located at a specified location with a subtended
visual angle of at least 3 minutes of arc for the worse case test
object, cylinder ``P''. The rationale for using a visual angle value
less than 5 minutes of arc for the school bus mirror requirements is
threefold.
---------------------------------------------------------------------------

    \83\ Garrott, W.R., Rockwell, T.H., and Kiger, S.W. (1990).
Ergonomic Research on School Bus Cross View Mirror Systems. National
Highway Traffic Safety Administration, DOT 807 676.
---------------------------------------------------------------------------

    First, school bus drivers must be specially licensed before they
can drive a school bus carrying children. They are required to obtain a
Commercial Drivers License with a School Bus Endorsement. The training
required to obtain this special license and the necessity of being
vigilant in all types of crashes in order to retain their license and
employment is expected to increase school bus drivers' awareness of the
possibility of pedestrians suddenly entering danger areas around their
bus. The combined effect of this training and the necessity for
attentiveness is expected to encourage drivers to pay more attention to
small images that are visible in a bus's mirrors.
    Second, school bus drivers are specifically trained in the use of
their bus's cross view mirrors. In the late 1980's, when the school bus
cross-view mirror requirements of FMVSS No. 111 were being developed,
49 states plus Washington, DC \84\ required annual training for all
school bus drivers in the use of their bus's cross view mirrors. This
training is expected to allow drivers to make better use of very small
images that they see.
---------------------------------------------------------------------------

    \84\ California had no such requirement.
---------------------------------------------------------------------------

    Third, school bus cross-view mirrors are intended to be used before
the bus begins to move, while the bus is stationary. As a result,
drivers can take as much time as they need to determine what they see
in their bus's cross-view mirrors. In contrast, in the passenger
vehicle environment, drivers may use the display while the vehicle is
stationary and while the vehicle is in motion backing up (albeit at
fairly low speeds). As a result, drivers may have limits on the amount
of time that they may use to determine what they are seeing in a
rearview video display. Again, this argues for a larger minimum image
size requirement.
    NHTSA considered whether the image size criterion used for school
bus cross-view mirror requirements currently in FMVSS No. 111 should
also be applied to rearview images required for passenger vehicles.
After careful consideration, NHTSA has concluded it is appropriate to
propose a stronger requirement for passenger vehicles since passenger
vehicle drivers do not have the same vehicle and system (e.g., mirror
use) training as school bus drivers do, nor do passenger vehicles
typically use the systems in a stationary scenario. Based on this, the
Satoh-recommended 5 minutes of arc subtended visual angle requirement
is warranted and therefore recommended as a minimum performance
requirement.
    Based upon NHTSA test data from an examination of a 2007 Honda
Odyssey minivan fitted both with an original equipment (from a 2008
Honda Odyssey) 2.4-inch diagonal rearview video display and an original
equipment 3.5-inch diagonal rearview video display (from a GM vehicle),
NHTSA estimates that a 2.8-inch or larger diagonal rearview video
display in the interior rearview mirror would be necessary to meet the
proposed 5 minutes of arc requirement for this vehicle.
b. Image Response Time
    Image response time is the time delay between the moment the
vehicle's transmission is shifted into reverse gear, and the moment
which an image to the rear of the vehicle is displayed. For vehicles in
which an existing navigation system visual display is used to display a
rearview video image, we believe that adopting a maximum image response
time value will prevent manufacturers from giving priority, at
ignition, to the loading of navigation system applications instead of
the rearview video applications. We believe that giving display
priority to a rearview video system image should increase the
effectiveness of such systems in preventing backing crashes. As stated
previously, NHTSA is concerned that if the display takes too long to
appear, drivers will be more likely to begin a backing maneuver before
the image of the area behind the vehicle is displayed. Given the
importance of the ``initial check'' behind the vehicle, a long image
response time could have a strong negative effect on the overall
effectiveness of a rearview video system. As an appropriate balance
between the importance of a quickly provided image and the need for
sufficient opportunity to conduct system checks as noted in the ANPRM
comments (see section IV.G), NHTSA proposes a 2.0-second maximum image
response time after the vehicle's transmission is shifted into reverse
based on the minimum time in which such system checks can be conducted.
c. Image Linger Time
    Image linger time refers to the period in which the rearview video
image continues to be displayed after the vehicle's transmission has
been shifted out of reverse gear. In the ANPRM, NHTSA indicated that a
maximum of 8 seconds of linger time may be appropriate after the
vehicle is shifted from the reverse position. Based on their
observations of drivers making parking maneuvers, the AAM recommended a
maximum linger time of 10 seconds or an alternative speed-based value
in which the rearview video display would turn off when the vehicle
reach a speed of 20 kph (12.4 mph).Similarly, GM recommended a maximum
linger time of 10 seconds or a speed-based limit of 5 mph (8 kph).
Based on commenters' findings regarding actual, observed maneuver
durations, NHTSA is proposing a time-based maximum linger time of 10.0
seconds to better aid to the driver.
d. Visual Display Luminance
    We believe it is appropriate to adopt a minimum visual display
luminance value to ensure that the rearview video system visual display
image is adequately visible in varying conditions, such as bright
sunlight or low levels of ambient light. Adequately visible, in this
case, would mean that a driver can discern the presence of and identify
obstacles displayed within the rearview video image. Gentex recommended
that a brightness level of 500 cd/m\2\ for in-mirror displays as
measured at room temperature and in a dark room, and said that it has
been confirmed by vehicle manufacturer research to be the minimally
accepted value, presumably to account for a wide possible range of
ambient conditions. Therefore, we are proposing a minimum visual
display luminance requirement of 500 cd/m\2\ for rearview image
displays.
e. Other Aspects of Visual Display
    NHTSA also requires comments regarding other aspects of visual
display and image quality performance such as image resolution,
minification, distortion, contrast ratio and low-light performance as
well as regarding display location. While existing systems may perform
well with regard to these aspects of performance, there is no certainty
that future systems will be designed to perform as well. Depending on
the public comments and other available information, we may include
requirements on some or all of these aspects of performance in the
final rule.

If we were to include requirements for some aspects, how should those
aspects be regulated, at what level of stringency, and why? For
example, what test procedures should be used for measuring these
aspects of performance? Do any existing voluntary consensus standards
have test procedures that would be appropriate for assessing
performance?
iii. Requirements for External System Components
    We believe that for rear visibility systems to be effective in
preventing real-world crashes, it is imperative that they perform
across a wide range of environments typically encountered by drivers.
For example, such systems should operate in various temperature ranges
and should not be rendered inoperable by conditions such as rain or
normal corrosion.
    As part of our technical review, we considered the possibility of
adopting requirements from industry consensus standards. Unfortunately,
such standards do not currently exist as manufacturers have indicated
they consider their internal technical specifications for such systems
to be proprietary. It is the agency's understanding that no such
industry consensus standards will be developed and available for
consideration within the timeframe of the current rulemaking process.
    Therefore, we reviewed existing requirements in our safety
standards for other vehicle equipment in these areas. We believe there
is merit in reviewing existing requirements for exterior motor vehicle
equipment, such as lighting, particularly because components such as
video cameras utilized in rearview video systems are typically mounted
near rear lamps and subject to the same environmental conditions. While
we considered that some vehicle manufacturers may conduct indirect
vehicle level environmental tests that could potentially address some
of these areas of interest, we noted that such testing is not required
and that there is no basis to believe all vehicle manufacturers would
adopt similar criteria. Therefore, based on the requirements outlined
in FMVSS No. 108 for lighting, we are proposing requirements for the
following areas to address rear visibility system external component
durability: Salt spray (fog), temperature cycle, and humidity.
    We believe a salt spray evaluation will address both the necessary
corrosion performance, as well as general moisture resistance required
so that rear visibility systems can deliver the expected effectiveness
to motorists in the real world. We are proposing that exterior
components used in rear visibility systems application meet the
required minimum performance of exterior lamps, which are required to
be tested in accordance with ASTM B117-73, Method of Salt Spray (Fog)
Testing for a total period of 50 hours. The 50 hour total period is
comprised of 2 identical periods of 24 hours of exposure followed by 1
hour of drying time. We believe that this standardized test procedure
is a reasonable proxy for normal environmental conditions. At the end
of the test, the system would still be required to meet the visibility
and field of view requirements.
    We believe a specification combining temperature cycles and
humidity levels is appropriate to establish the ability of rearview
video systems to provide the anticipated level of effectiveness across
a range of real world driving conditions. We are proposing to require
that systems operated across both a high and low temperature range,
with varying humidity level. Again, at the conclusion of the proposed
test cycles, the system would be required to function within acceptable
limits.

B. Proposed Compliance Tests

i. Ambient Lighting Conditions
    NHTSA believes that the ambient lighting conditions present for
testing should mimic the lighting conditions in which the visual
displays will be used. To ensure test repeatability, NHTSA believes
that ambient lighting of a particular brightness level should be
specified for testing. Daytime outdoor lighting (sunlight and varying
degrees of cloud cover) ranges from 10,000 lux to 100,000 lux in full
sunlight.\85\ NHTSA believes that the lower end of this brightness
range should be used for testing to mimic the most typical manner of
incidence of the sun's rays upon a console-mounted rearview image,
which would involve at least some degree of obstruction by the
vehicle's roof. Therefore, we propose that testing be conducted with
evenly distributed lighting of 10,000 lux intensity as measured at the
center of the exterior surface of vehicle's roof. While actual natural
sunlight may strike an in-vehicle display at various angles through the
day, for the purpose of test repeatability we believe that ambient
lighting during testing should be provided by overhead light sources
with the light presented in an evenly distributed manner. Because the
overwhelming majority of backover crashes occur during the day, we are
not proposing testing under nighttime ambient lighting conditions.
---------------------------------------------------------------------------

    \85\ Ander, Gregg D. (1995). Daylighting performance and design.
Wiley, John & Sons, Incorporated.
---------------------------------------------------------------------------

ii. Rear Visibility Test Object
    For the purpose of determining compliance with the performance
requirements specified in the preceding sections, NHTSA is proposing
that a cylindrical test object be used for testing. Specifically, the
agency is proposing the test cylinder be a 32-inch tall cylinder with a
diameter of 12 inches to represent the approximate height and width of
an average, standing 18-month-old child. The age of 18 months was
selected based upon the agency's review of SCI backover cases and
consideration of comments on the ANPRM. We believe that a test object
with these dimensions is necessary to ensure robust performance not
only of a countermeasure system's ability to meet specified coverage
area requirements behind a vehicle, but also the system's ability to
display an image of a rear obstacle to a driver.
    In developing the characteristics of the test object, NHTSA
reviewed its own research, real world crash data, industry research,
existing test procedures, and comments on the ANPRM. NHTSA considered
and evaluated a number of different options ranging from crash dummies,
clothing mannequins, and polyvinyl chloride (PVC) pipe to traffic cones
for use as possible compliance test objects. NHTSA also considered
using a child-shaped, clothing mannequin identified by the agency's
Advanced Collision Avoidance Technology (ACAT) Backing Crash
Countermeasure Program as having a radar cross-section equivalent to
that of a small child. However, this shape is not proposed since the
sensitivity of the test object to radar detection is not relevant to
the evaluation of a visual rearview image and the asymmetrical shape of
the mannequin would cause rearview image quality measurement
difficulties. Given that the test object is intended to be used both to
confirm countermeasure coverage area and test cylinder displayed size,
a shape that is conducive to accurate completion of both tests is
needed. While the shape of the test object is not critical for
assessment of countermeasure coverage area as long as the object's
dimensions are appropriate, use of a sided shape could cause
measurement difficulties when assessing visual display image quality. A
cylindrical test object with a vertical axis would appear to have the
same relative width regardless of the angle at which it is viewed and
would not appear skewed, as a square column might. A cylindrical test
object is also

suggested by the requirements of ISO 17386 that specify use of a
cylinder to test the detection performance of ultrasonic parking aids.
Therefore, the proposed test object shape consists of a cylinder with a
vertical axis that can adequately represent the proportions of the
children most commonly at risk in backover scenarios while at the same
time ensuring robust system performance.
    To best represent the manner in which a child is displayed to the
driver in a rearview image, NHTSA proposes that the cylindrical test
object shall have a diameter of 12 inches to represent the width of an
average 18-month-old child. Based on 2000 CDC data for the head breadth
an 18-month-old child, NHTSA proposes 5.9 inches (15 cm) as the minimum
width that must be visible in the rearview image for the three test
objects located nearest the rear bumper of the vehicle.\86\ To aid in
the assessment of whether the minimum width is visible, a contrasting
colored vertical stripe of width 5.9 inches is proposed for the two
cylinders closest to the vehicle.
---------------------------------------------------------------------------

    \86\ CDC, Clinical Growth Charts. Birth to 36 months: Boys;
Length-for-age and Weight-for-age percentiles. Published May 30,
2000 (modified 4/20/2001) CDC, Clinical Growth Charts. Birth to 36
months: Girls; Length-for-age and Weight-for-age percentiles.
Published May 30, 2000 (modified 4/20/2001).
---------------------------------------------------------------------------

    Furthermore, given that the visual appearance of the test object is
the dominant factor in the compliance test, we do not believe that we
need to specify material properties at this time. While ultrasonic and
radar sensors are better at detecting some materials and surface
textures than others, rearview video systems display images of objects
of all opaque material types. For these reasons, NHTSA is proposing
that the test object merely consist of a cylindrical object of the
dimensions specified above. However, we note that if in the future
sensor-based systems are developed that may fulfill the requirements of
providing to the driver a visual image of the area behind the vehicle,
alternative test object material characteristics and dimensions may
need to be specified in order to ensure that the object accurately
simulates the physical presence of an 18-month-old child to the
particular sensor technology being used.
    To provide a consistent and repeatable location in which to measure
apparent test object width as part of rearview image quality
assessment, NHTSA proposes that the three rearmost test objects be
constructed with a 5.9-inch high colored band surrounding the perimeter
of the upper portion of the cylinder that is of a different color than
the rest of the cylinder. The 5.9-inch dimension is based on the
breadth of the average 18-month-old child's head.\87\ The band can be
of any color that contrasts with that of the rest of the test object.
---------------------------------------------------------------------------

    \87\ CDC, Clinical Growth Charts. Birth to 36 months: Boys;
Length-for-age and Weight-for-age percentiles. Published May 30,
2000 (modified 4/20/2001) CDC, Clinical Growth Charts. Birth to 36
months: Girls; Length-for-age and Weight-for-age percentiles.
Published May 30, 2000 (modified 4/20/2001).
---------------------------------------------------------------------------

iii. Rear Visibility Compliance Test Procedures
    NHTSA is proposing a test to ensure that a rearview image provided
to the driver (1) covers the required area behind the vehicle and (2)
displays the images of obstacles with sufficient size to permit a
driver to visually perceive their presence. The test procedure used to
determine countermeasure performance in terms of rearview video system
viewable area is similar to that currently used for school bus mirrors
(Section 13, ``School bus mirror test procedures'' of FMVSS No. 111,
``Rearview mirrors''). Like the school bus mirror test, the proposed
test uses a large format camera placed with the imaging sensor located
at a specific eyepoint location, referred to here as the ``test
reference point''. A matte finish ruler affixed beneath the visual
display and aligned laterally along the bottom edge of the visual
display provides a reference for scaling purposes in the image quality
portion of the test procedure.
    The proposed test reference point is intended to simulate the
location of a 50th percentile male driver's eyes (rather than the 95th
percentile male used in existing FMVSS No. 111 rearview mirror
requirements) when glancing at the rearview image. Based on
observations of drivers using rearview video systems in NHTSA
testing,\88\ we assume that for visual displays located in the vicinity
of the center console or interior rearview mirror, the driver will turn
his or her head to look at the display with little or no lateral eye
rotation. Therefore, to estimate the location of the driver's eyes when
looking at a rearview image, the forward-looking eyepoint of the driver
can be simulated to rotate toward the center of the vehicle as though
the driver is turning his head. Anthropometric data from a NHTSA-
sponsored study of the dimensions of 50th percentile male drivers
seated with a 25-degree seat-back angle (``Anthropometry of Motor
Vehicle Occupants'' \89\) give the longitudinal and vertical location,
with respect to the H point, of the left and right infraorbitale (a
point just below each eye) and the head/neck joint center at which the
head rotates about the spine. Given an average vertical eye diameter of
approximately 0.96 inch (24 mm), we can assume that the center of the
eye is located 0.48 inches (12 mm) above the infraorbitale. Taking the
midpoint of the lateral locations of the driver's eyes gives a point in
the mid-sagittal plane (the vertical/longitudinal plane of symmetry of
the human body) of the driver's body indicated by Mf in
Figure 5. Using the point at which the head rotates, Mf can
be rotated toward the rearview image to obtain a new eyepoint, the test
reference point, representing an eye midpoint for a driver when the
head is turned to look at a rearview image. The proposed regulatory
requirement sets forth clear instructions as to how to position the
camera to conduct the test.
---------------------------------------------------------------------------

    \88\ Mazzae, E.N., Barickman, F.S., Baldwin, G.H.S., and Ranney,
T.A. (2008). On-Road Study of Drivers' Use of Rearview Video Systems
(ORSDURVS). National Highway Traffic Safety Administration, DOT 811
024.
    \89\ Schneider, L.W., Robbins, D.H., Pfl[uuml]g, M.A. and
Snyder, R.G. (1985). Anthropometry of Motor Vehicle Occupants;
Volume 1--Procedures, Summary Findings and Appendices. National
Highway Traffic Safety Administration, DOT 806 715.
---------------------------------------------------------------------------

BILLING CODE 4910-59-P

[GRAPHIC] [TIFF OMITTED] TP07DE10.011

a. Rear Field of View Test Procedure
    To demonstrate a system's compliance with the field of view
requirements, we are proposing that the perimeter of the minimum
detection area that must be visible is marked using seven test objects.
The locations of the seven test objects, represented by black circles,
are illustrated in Figure 6.

[GRAPHIC] [TIFF OMITTED] TP07DE10.012

BILLING CODE 4910-59-C
    For school bus cross-view mirrors, FMVSS No. 111 requires that the
entire top surface of each cylinder must be visible. However, due to
the potential for rearview video cameras to be mounted at heights of
less than 32 inches on some compact cars and sporty vehicles, NHTSA is
proposing an alternative detection criterion for this test. For test
objects located 10 or more feet aft of the vehicle's rear bumper, NHTSA
proposes that the entire height and width of each test object must be
visible. This criterion equates to the driver being able to see the
entire body

of an 18-month-old child and serves to ensure that detection of a
child, if present, between 10 and 15 feet behind the vehicle is
possible.
    Due to camera angle, only a portion of a child or child-sized
object in close proximity to the rear bumper may be visible,
particularly at the edges of the camera's viewing angle. To ensure that
at least a portion of test objects `F' and `G' (in Figure 6) are
visible, the proposed compliance test positions them 1 foot aft of the
rear bumper face. To give the driver enough information to be able to
discern an ``object'' as a child, if present, and to provide a
quantitative basis for assessing field of view compliance, NHTSA
believes it is important to indicate how much of the test objects must
be visible. Seeing a child's face or another body area of similar size
would likely result in successful visual recognition of the child by
the driver. Therefore, NHTSA proposes that a minimum of a 5.9-inch
width of test objects `F' and `G' must be visible.\90\ This criterion
would result in a 5.9-inch square or larger portion of an object or
child being visible.
---------------------------------------------------------------------------

    \90\ The 5.9-inch dimension is the average breadth of an 18-
month-old child's head per CDC's ``Clinical Growth Charts. Birth to
36 months: Boys; Length-for-age and Weight-for-age percentiles'' and
``Clinical Growth Charts. Birth to 36 months: Girls; Length-for-age
and Weight-for-age percentiles.'' Published May 30, 2000 (modified
4/20/2001).
---------------------------------------------------------------------------

    For NHTSA compliance testing, the displayed rearview image would be
photographed to document the test results of this field of view test,
as well as to provide data for use in completing the image quality
test, which is described in the next section.
b. Rearview Image Size Test Procedure
    As stated previously, industry standards applicable to an image-
based rear visibility system do not exist. Therefore, to develop a
method for assessing image quality, NHTSA looked to its prior work
relating to school bus cross-view mirrors. The test procedure described
below follows the same basic concept as the existing school bus mirror
test procedure in FMVSS No. 111. This test serves to ensure that a
minimum image quality is maintained throughout the required coverage
area of the rearview image. Essentially, we are proposing that the
apparent image of the individual test objects be large enough for an
average driver to quickly determine their presence and nature.
    The test procedure proposed for use in assessing countermeasure
visual display image quality compliance requires one additional step
beyond the rearview video system viewable area test described above.
Using the printed photograph of the rearview image taken to document
the viewable area covered by the system, the size of each of the three
test objects positioned 20 feet aft of the rear bumper (indicated in
Figure 5 labeled `A', `B', and `C') is measured. The horizontal width
of each of the three test objects is measured within the colored band
surrounding the upper portion of the cylindrical test object by
selecting a point at both the left and right edges of the object's
displayed image. Similarly, two points on the ruler shown in the
photograph are selected to acquire a measurement for use as a lateral
scaling factor. Using the two measure widths and the distance between
the driver's eyepoint (i.e., midpoint between an average 50th
percentile male's eyes) and the center of the rearview image, the
visual angle subtended by each test object may be calculated. To reduce
the effects of measurement errors, the measured visual angle subtended
from each of the three test objects (A, B, and C) are averaged
together. Acceptable image quality is defined as the average measured
visual angle subtended by the test object's width from these three
locations exceeding 5 minutes of arc. The average value is used to
assess compliance to minimize the effect of individual measurement
error. The subtended visual angle for each of the three locations must
exceed 3 minutes of arc.

C. Proposed Effective Date and Phase-In Schedule

    In accordance with the schedule set forth by Congress in the K.T.
Safety Act, we are proposing that the requirement for rearview video
systems be phased in within four years of publication of the final
rule. Because we anticipate that a final rule will be published in
early 2011, the statutory requirement would require that full
compliance be achieved in late 2014 or early 2015. Furthermore, because
we anticipate that this rule will require substantial design work to
implement, we are proposing that, like other substantial rules, the
compliance dates for the various stages of the phase-in be September 1
of the relevant year, in order to correspond with model years.
Therefore, given the likely schedule of this rulemaking, we are
proposing that full compliance be achieved by September 1, 2014.
    NHTSA is concerned about the potential costs imposed on automotive
manufacturers by this proposal, and is therefore taking into account
both the current and projected future implementation of rearview video
systems in our proposed phase-in schedule. Another factor that is being
taken into consideration is the vehicle redesign cycle. Specifically,
we are aware that it could cost substantially more to implement the
best available technology (i.e., rearview video systems) into vehicles
if it is not done during the normal vehicle design cycle. We are aware,
for example, in comments received from Honda that the statutory
deadline may not provide enough time for most vehicles to undergo a
redesign before full compliance is required. In its comment, AIAM
suggested that a 6-year phase-in schedule, rather than a 4-year one,
might be needed in order to assure that the substantial majority of
affected vehicles can integrate rearview video systems as part of their
normal redesign cycle. The agency appreciates the challenges posed by
the proposed rule, but notes that a phase-in period longer than four
years would be inconsistent with the limitation specified by Congress.
    With the above considerations, we are proposing a rear-loaded
phase-in schedule. For the year following the first September 1 after
publication of the final rule (likely to be September 1, 2011), we are
proposing a compliance target that is less than the total number of
vehicles already anticipated to be equipped with rearview video
systems. The proposed phase-in schedule then requires steady increases
in the total percentage of the compliant vehicles in the two following
years, based on these considerations and the percentage of vehicles
that are anticipated to undergo a scheduled redesign. Finally, we are
proposing to apply the requirements to all vehicles manufactured on or
after September 1 of the following year (likely 2014). The specific
percentages of the phase-in schedule are shown in Table 11 below.

                  Table 11--Proposed Phase-In Schedule
------------------------------------------------------------------------
                                                                 Percent
------------------------------------------------------------------------
Vehicles manufactured before September 1, 2011.................        0
Vehicles manufactured on or after September 1, 2011, and before        0
 September 1, 2012.............................................
Vehicles manufactured on or after September 1, 2012, and before       10
 September 1, 2013.............................................
Vehicles manufactured on or after September 1, 2013, and before       40
 September 1, 2014.............................................
Vehicles manufactured on or after September 1, 2014............      100
------------------------------------------------------------------------

    Furthermore, we are proposing that small volume manufacturers need
only comply with the requirement for

rearview video systems when the requirement has been fully phased in,
that is, on September 1, 2014. This is based in part on the comment
from AIAM, which requested this provision for small volume
manufacturers due to their longer product life cycles and their reduced
access to technology.
    The reasons for allowing small volume manufacturers a delay in the
compliance schedule are twofold. First, because these manufacturers
generally produce a single or low number of lines of vehicles, they
would need to install these systems on a large portion or all of their
fleet in order to meet the fleet percentage requirement. Considering
that the installation of rearview video systems is most efficiently
accomplished during a vehicle redesign, this would mean that small
volume manufacturers are disproportionately negatively impacted by the
requirement because they would likely have to install these systems in
the middle of the design cycle, increasing their costs. Second, because
small volume manufacturers frequently have longer product cycles than
larger manufacturers, the need for a delay until the end of the
compliance increases the likelihood that they will have the opportunity
to integrate the rearview video system with their normal redesign
cycle. While we believe that rearview video systems and displays are
readily available so that small volume manufacturers will have access,
we believe that the other two reasons are adequate to delay mandatory
compliance until the end of the phase-in period.
    We are also proposing to include provisions under which
manufacturers can earn credits towards meeting the applicable phase-in
percentages if they meet the new rear visibility requirements ahead of
schedule. In addition, as we have done with other standards, we are
proposing a separate alternative schedule to address the special
problems faced by limited line and multistage manufacturers and
alterers in complying with phase-ins. A phase-in generally permits
vehicle manufacturers flexibility with respect to which vehicles they
choose to initially redesign to comply with new requirements. However,
if a manufacturer produces a very limited number of lines, a phase-in
would not provide such flexibility. NHTSA is accordingly proposing to
permit ``limited line'' manufacturers that produce three or fewer
carlines the option of achieving full compliance when the phase-in is
completed. Flexibility would be allowed for vehicles manufactured in
two or more stages and altered vehicles from the phase-in requirements.
These vehicles would not be required to meet the phase-in schedule and
would not have to achieve full compliance until the phase-in is
completed. Also, as with previous phase-ins, NHTSA is proposing
reporting requirements to accompany the phase-in.

D. Summary of Estimated Effectiveness, Costs and Benefits of Available
Technologies

i. System Effectiveness
    Some systems, like airbags, have binary states; that is to say that
either they are activated or they are not. Analysis includes a
probability of whether or not it was being used, followed by a
calculation of benefits in cases where it was in use.
    For rear visibility technologies, three conditions must be met for
such a technology to provide a benefit to the driver. First, the crash
must be one that is ``avoidable'' through use of the device; i.e., the
pedestrian must be within the target range for the sensor, or the
viewable area of the camera or mirror. Second, once the pedestrian is
within the system's range, the device must ``sense'' that fact, i.e.,
provide the driver with information about the presence and location of
the pedestrian. Third, there must be sufficient ``driver response,''
i.e., before impact with the pedestrian, the driver must receive this
information and respond appropriately by confirming whether someone is
or is not behind the vehicle before proceeding. As noted above, these
factors are denoted as fA, fS, and
fDR, respectively, in this analysis. Table 12 below shows
these factors and their product, the final system effectiveness.

                                      Table 12--Final System Effectiveness
----------------------------------------------------------------------------------------------------------------
                                                                                Final  effectiveness
                          System                             FA (%)    FS (%)    FDR (%)  (%) FA x FS x FDR = FE
----------------------------------------------------------------------------------------------------------------
180[deg] Camera...........................................        90       100        55                    49
130[deg] Camera...........................................        76       100         5                    42
Ultrasonic................................................        49        70         7                     2.5
Radar.....................................................        54        70         7                     2.7
Mirrors...................................................      * 33       100      ** 0                     0
----------------------------------------------------------------------------------------------------------------
* FA for mirrors is taken from separate source due to lack of inclusion in the SCI case review that generated FA
  for cameras and sensors.
** FDR for mirrors is taken from a small sample size of 20 tests. It is 0% because throughout testing, drivers
  did not take advantage of either cross-view or lookdown mirrors to avoid the obstacle in the test.

ii. Costs
    The most expensive technology option that the agency has evaluated
is the rearview camera. When installed in a vehicle without any
existing adequate display screen, rearview camera systems are estimated
to cost consumers between $159 and $203 per vehicle. For a vehicle that
already has an adequate display, such as one found in navigation units,
their incremental cost is estimated at $58. The total incremental cost
to equip a 16.6 million vehicle fleet with camera systems is estimated
to be $1.9 to $2.7 billion.
    Rear object sensor systems are estimated to cost between $52 and
$92 per vehicle. The total incremental cost to equip a 16.6 million
vehicle fleet with sensor systems is estimated to be $0.3 to $1.2
billion.
    Several different types of mirrors were investigated. Interior
look-down mirrors could be mounted on vans and SUVs, but not cars, and
are estimated to cost $40 per vehicle. The total incremental cost to
equip a 16.6 million vehicle fleet with lookdown mirrors is estimated
to be $0.6 billion.
    We also estimated the net property damage effects to consumers from
using a camera or sensor system to avoid backing into fixed objects,
along with the additional cost when a vehicle is struck in the rear and
the camera or sensor is destroyed.

                    Table 13--Costs (2007 Economics)
------------------------------------------------------------------------

------------------------------------------------------------------------
Costs Per Vehicle....................  $51.49 to $202.94.
Total Fleet..........................  $723M to $2.4B.
------------------------------------------------------------------------

iii. Benefits
    As noted above, the agency has spent considerable effort trying to
determine the final effectiveness of these systems in reducing crashes,
injuries and fatalities. We have researched the capabilities of the
systems, the crash circumstances, and the percent of drivers that would
observe and react in time to avoid a collision with a pedestrian or
pedalcyclist. The estimated injury and fatality benefits of the various
systems, based on NHTSA research to date, are shown below.

                                         Table 14--Quantifiable Benefits
----------------------------------------------------------------------------------------------------------------
                                              180[deg]      130[deg]                                  Look-down
                                             Camera view   Camera view   Ultrasonic       Radar        mirror
----------------------------------------------------------------------------------------------------------------
Fatalities Reduced........................           112            95             3             3             0
Injuries Reduced..........................         8,374         7,072           233           257             0
----------------------------------------------------------------------------------------------------------------

iv. Net Benefits
    In addition to the one-time installation costs, and the benefits
that occur over the life of the vehicle, there would also be
maintenance costs as well as repair costs due to rear-end collisions
and ``property damage only crashes'' (which, like the benefits, occur
over time). Below Table 15 contains lifetime monetized benefits and
lifetime costs, and their difference, the net benefit. In this case,
the quantifiable costs outweigh the quantifiable benefits and therefore
the final number is a cost. (Note that this analysis does not include
nonquantifiable benefits, a point to which we will shortly return.) The
primary estimate is based on a 130 degree camera system with an in-
mirror display. The low estimate is based on an ultrasonic system. The
high estimate is based on a 180 degree camera system with an in-mirror
display.

 Table 15--Summary of Benefits and Costs Passenger Cars and Light Trucks (Millions 2007$) MY 2016 and Thereafter
----------------------------------------------------------------------------------------------------------------
                                                             Primary                      High        Discount
                                                            estimate    Low estimate    estimate      rate (%)
----------------------------------------------------------------------------------------------------------------
Benefits:
    Lifetime Monetized..................................        $618.6         $37.1        $732.6             7
    Lifetime Monetized..................................         777.6          46.7         920.8             3
Costs:
    Lifetime Monetized..................................       1,933.3          22.6       2,362.4             7
    Lifetime Monetized..................................       1,861.3         730.4       2,296.9             3
Net Benefits:
    Lifetime Monetized..................................      -1,314.7        -685.5      -1,629.8             7
    Lifetime Monetized..................................      -1,083.7        -683.7      -1,376.1             3
----------------------------------------------------------------------------------------------------------------

v. Cost Effectiveness
    While we examine several application scenarios (all passenger cars
and all light trucks, only light trucks, and some combinations) and
discount rates of 3 and 7 percent, the net cost per equivalent life
saved for camera systems ranged from $11.8 to $19.7 million. For
sensors, it ranged from $95.5 to $192.3 million per life saved.
According to our present model, none of the systems are cost effective
based on our comprehensive cost estimate of the value of a statistical
life of $6.1 million.

                Table 16--Cost per Equivalent Life Saved
------------------------------------------------------------------------

------------------------------------------------------------------------
                     Cost per equivalent life saved
------------------------------------------------------------------------
Sensors (Ultrasonic and Radar).........  $95.5 to $192.3 mill.
Camera Systems.........................  $11.8 to $19.7 mill.
------------------------------------------------------------------------
The range presented is from a 3% to 7% discount rate.

    The agency is proposing requirements that would likely be currently
met by using cameras for both passenger cars and light trucks. We also
seek comment on an alternative aimed at reducing net costs that could
be met by requiring having cameras for light trucks and either cameras
or ultrasonic sensors for passenger cars. We also request comment on
the extent to which the effectiveness of sensors and the response of
drivers to sensor warnings could be improved.

E. Comparison of Regulatory Alternatives

    In order to explore fully other possible rulemaking options, the
agency examined a variety of combinations of technology, specifically,
ones in which light trucks were equipped with a rearview video system
and passenger cars were either given no extra equipment, a rearview
video system (using a camera) or another technology such as a sensor
system. The results of examining such combinations are available below.
Note the camera/radar and camera/ultrasonic options have decreased
costs compared to mandating cameras for both vehicle types, but have a
higher cost per life saved. It would not fulfill the requirements of
the statute to require cameras for light trucks and nothing for
passenger cars; those numbers are provided only as a point of
comparison. Also, the camera/radar option has a higher net costs
associated with it than simply mandating cameras for both, and will
most likely not be viable on those grounds. Comments on these
alternatives and suggestions of others are welcome.

                      Table 17--Rear Visibility Proposal and Alternatives Discounted at 3%
                                              [Millions of 2007 $]
                    [In decreasing order of installation costs and monetized safety benefits]
----------------------------------------------------------------------------------------------------------------
                                             Per vehicle costs and benefits
                              ------------------------------------------------------------
  Proposal and alternatives                       Monetized   Property                          Net cost per
                                 Installation      safety      damage        Net costs     equivalent life saved
                                  costs \91\      Benefits      costs
----------------------------------------------------------------------------------------------------------------
LT Camera, PC Camera.........  $1,919 to $2,275        $778       $-414  $727 to $1,084..  $11.8 to $14.6.
LT Camera, PC Radar..........  $1,512 to $1,710         439        -149  $924 to $1,122    $18.9 to $21.7.\93\
                                                                          \92\.
LT Camera, PC Ultrasonic \94\  $1,215 to $1,413         437        -165  $613 to $811....  $14.7 to $17.4.
LT Camera, PC Nothing \95\...  $841 to $1,039..         415        -189  $237 to $435....  $9.6 to $12.5.
----------------------------------------------------------------------------------------------------------------

    The most effective technology option that the agency has evaluated
is the rearview video system which, as already noted, consists of a
video camera and a visual display. It is also the most expensive
technology. When installed in a vehicle that does not already have any
visual display screen, rearview video systems are estimated to cost
consumers between $159 and $203 per vehicle. The upper end of the cost
range is based on systems that have in-mirror (as opposed to in-dash or
console) displays and a 180 degree (as opposed to 130 degree) lens. For
a vehicle that already has a suitable visual display, such as one found
in navigation units, the incremental cost of a rearview video system is
estimated at $58-$88, depending on the angular width of the lens. The
total incremental cost to equip a 16.6 million vehicle fleet with
rearview video systems is estimated to be $1.9 to $2.7 billion.
---------------------------------------------------------------------------

    \91\ The range of camera costs assumes 130 degree camera with
the display in the dash (lower cost) to the display in the mirror
(higher cost).
    \92\ The net costs are substantially more than those for any of
the other options.
    \93\ The cost per equivalent life saved is substantially more
for this option than that for any of the other options.
    \94\ Under this alternative, passenger cars could be equipped
with either sensor systems or camera systems. For a fuller
description of this alternative, see the discussion above at the
very end of section I, Executive Summary.
    \95\ The agency tentatively concludes that not requiring any
improved performance by passenger cars would be inconsistent with
the mandate in the Cameron Gulbransen Kids Transportation Safety Act
of 2007.
---------------------------------------------------------------------------

    Commenters on the ANPRM noted that rearview video systems are a
relatively new technology and stated that considerable reductions in
costs will occur as these technologies proliferate in the fleet. NHTSA
agrees that technological innovation will occur over the next couple of
years and that the costs are likely to be substantially less when
actually installed in future model years. However, we have not
identified a way to estimate this lower cost.
    Given the effectiveness estimates that we have generated and
assuming that all vehicles will be equipped with the most likely
countermeasure technology, namely a rearview video system and
associated display, we believe the fatalities that are occurring in
backing crashes could be reduced by 95 to 112 per year. Similarly,
injuries would be reduced by 7,072 to 8,374 per year. We estimate that
the cost per equivalent lives for rearview video systems would range
from $11.8 million based on a 3% discount rate and on the low end of
the per vehicle cost range to $19.7 million based on a 7% discount rate
and the high end of the per vehicle cost range.
    We note that while this cost per equivalent lives saved, even at
the low end, is nearly double the Departmental value of a statistical
life of $6.1 million,\96\ the proposed solution is the most
comprehensive and effective, currently available solution to mitigate
backover crashes, fatalities, and injuries. As we discussed above, the
quantitative analysis does not offer a complete accounting. We have
noted that well over 40 percent of the victims of backover crashes are
very young children (under the age of five), with nearly their entire
life ahead of them. Executive Order 12866 also refers explicitly to
considerations of equity. (``(I)n choosing among alternative regulatory
approaches, agencies should select those approaches that maximize net
benefits (including * * * equity), and there are strong reasons,
grounded in those considerations, to prevent the deaths at issue here.
In addition, this regulation will, in many cases, reduce a
qualitatively distinct risk, which is that of directly causing the
death or injury of one's own child.\97\ Drivers will also benefit from
increased rear visibility in a variety of ways, including increased
ease and convenience with respect to parking.
---------------------------------------------------------------------------

    \96\ The $6.1 million represents the 2007 Departmental value of
$5.8 million for a statistical life (VSL) adjusted for economic cost
factors that are not inherently a part of the $5.8 million. These
include, medical care, emergency services, legal costs, insurance
administrative costs, workplace costs, property damage and the taxed
portion of lost market productivity (the untaxed portion is assumed
to be inherently included in the VSL).
    \97\ On the relevance of this fact, see J.K. Hammitt and K.
Haninger, ``Valuing Fatal Risks to Children and Adults: Effects of
Disease, Latency, and Risk Aversion,'' Journal of Risk and
Uncertainty 40(1): 57-83, 2010.
---------------------------------------------------------------------------

    While these benefits cannot be monetized, they could be
significant. A breakeven analysis suggests that if the nonquantified
benefits amount $65 to $79 per vehicle, the benefits would justify the
costs. Taking all of the foregoing points alongside the quantifiable
figures and the safety issue at hand, the agency tentatively concludes
that the benefits do justify the costs. More specifically, we emphasize
the following data and considerations:
     100 of the 228 (44%) annual victims of backover crashes
are under 5 years of age with nearly their entire lives ahead of them;
80 of the 100 children are under 3 years of age.\98\
---------------------------------------------------------------------------

    \98\ Executive Order 13045, Protection of Children from
Environmental Health Risks and Safety Risks * * * Section 1. Policy.
1-101. A growing body of scientific knowledge demonstrates that
children may suffer disproportionately from * * * safety risks.
These risks arise because: children's neurological, immunological,
digestive, and other bodily systems are still developing; * * * and
children's behavior patterns may make them more susceptible to
accidents because they are less able to protect themselves. * * *
---------------------------------------------------------------------------

     While this rulemaking would result in great cost if made
final as proposed, it would also have substantial benefits, reducing
the annual fatalities in backover crashes by 95 to 112 fatalities, and
annual injuries by 7,072 to 8,374 injuries.
     In addition to those benefits, there are other benefits
that are hard to quantify, but are nonetheless real and significant.
One such benefit is that of not being the direct cause of the death or
injury of a person and particularly a small child at one's place of
residence. In some of these cases, parents are responsible for the
deaths of their own children; avoiding that horrible outcome is a
significant benefit. Another hard-to-

quantify benefit is the increased ease and convenience of driving, and
especially parking, that extend beyond the prevention of crashes. While
these benefits cannot be monetized at this time, they could be
considerable.
     There is evidence that many people value the lives of
children more than the lives of adults.\99\ \100\ In any event, there
is special social solicitude for protection of children. In the area of
motor vehicle safety, this special solicitude for the welfare of
children has been evident in the area of motor vehicle safety in the
mandates \101\ by Congress over the years for issuing standards
primarily benefiting children. This solicitude regarding children is
based, to a significant extent, on their greater vulnerability to
injury and their inability to protect themselves.
---------------------------------------------------------------------------

    \99\ J.K. Hammitt and K. Haninger, ``Valuing Fatal Risks to
Children and Adults: Effects of Disease, Latency, and Risk
Aversion,'' Journal of Risk and Uncertainty 40(1): 57-83, 2010. This
stated preference study finds that the willingness to pay to prevent
fatality risks to one's child is uniformly larger than that to
reduce risk to another adult or to oneself. Estimated values per
statistical life are $6-10 million for adults and $12-15 million for
children. We emphasize that the literature is in a state of
development.
    \100\ Other people argue for valuing all lives equally,
regardless of age, and note there is also a special solicitude for
another vulnerable population, the elderly. Some of the elderly have
difficulty quickly moving out of dangerous situations. Special
solicitude for the elderly is very germane to this rulemaking given
that persons 70 years of age or older account for another large
segment of fatalities, i.e., 74 (33 percent) of the 228 annual
fatalities.
    \101\ Recent examples include Anton's Law, Public Law 107-318,
Dec. 4, 2002, and the K.T. Safety Act. That solicitude is also
evident in the requirement in Omnibus Consolidated and Emergency
Supplemental Appropriations Act of 1999, Public Law 105-277 (5
U.S.C. 601 note) for assessment of impacts of Federal regulations
and policies on families.
---------------------------------------------------------------------------

     Given the very young age of most of the children fatally-
injured in backover crashes, attempting to provide them with training
relevant to the particular circumstances of those crashes or with an
audible warning would not enable them to identify or take steps to
protect themselves, given their impulsiveness, their lack of
understanding of the abstract concept of risk/danger/safety, and their
lack of situational awareness, judgment and physical ability (e.g.,
dexterity) to take timely and effective self-protective action.
     Given the impossibility of reducing backover crashes
through changing the behavior of very young children and given
Congress' mandate, it is reasonable and necessary to rely on vehicle
technology to address backover crashes and to that end the agency
examined a variety of technologies to assess their value in improving
driver awareness and performance: mirrors, sensors, cameras, and other
technologies.
     Based on its extensive testing to determine how much area
behind a vehicle a driver must be able to see in order to avoid
backover crashes and on the relative effectiveness of the various
technologies in improving driver awareness and performance, the agency
has tentatively concluded that a camera-based system is the only
effective type of technology currently available.
     Requiring additional rearview mirrors or changes to
existing review mirrors cannot provide an effective solution to the
problem of backover crashes. Changes to outside rearview mirrors
mounted near the driver offer only very limited opportunities for any
improvement in the existing rearward view to the sides of vehicles and
no opportunity for providing any view of the area directly behind
vehicles. While rearview mirrors mounted at or near the rear of
vehicles could provide a view to the rear of vehicles, the coverage
area would be relatively small. Further, the image, as viewed by the
driver indirectly via outside rearview mirrors mounted near the driver,
would be fairly small and distorted, making the viewed objects
difficult to discern. Finally, rear-mounted rearview mirrors might not
be reasonable, practicable and appropriate for many types of light
vehicles.
     The agency's testing indicated that currently available
sensors, which are designed primarily to avoid collisions with objects
(like posts and other vehicles) that can cause property damage, had two
shortcomings. First, they often failed to detect a human, particularly
a small moving child, in tests in which the vehicle was not actually
moving. Second, in tests in which the vehicle was moving, and in which
the sensors did detect a manikin representing a child, the resulting
warning did not induce drivers to pause more than briefly in backing.
Being unable to confirm visually whether there was something or someone
behind them, the drivers in these tests resumed their backing.
     In contrast, in the agency's tests of vehicles equipped
with video camera-based systems, drivers not only saw a child-sized
obstacle, but also stopped and remained stopped, thereby avoiding
striking the obstacle in a substantial percentage of the tests.
     Consequently, the agency has tentatively concluded that
requirements must have the effect of ensuring that the driver is
provided with some type of image of the area directly behind his or her
vehicle. However, the agency is not proposing to require that video
camera-based systems be installed to provide that image.
     Instead, the agency is proposing a performance-based
requirement for any system that can provide the driver with the
requisite image. The proposal does not specify a single location within
the vehicle as the location in which the image must be provided. Thus,
the image can be provided on a display in the dash or interior rearview
mirror.
     In time, types of technology other than a video camera-
based system may be able to provide a sufficiently clear visual image
of the area behind the vehicle at lower cost than a video camera-based
system can.
     In proposing a requirement that drivers must be provided
with a visual image of the area behind their vehicles, the agency
recognizes that among currently available candidate technologies, video
cameras are the most expensive and mirrors are the least. Sensors fall
in between.
     The agency's estimates of current costs for video camera-
based systems may be too high as the estimates are based on data that
are a few years old.
     The agency has a contract in place for the conducting of
up-to-date tear down cost studies of both camera and sensor
technologies. These studies could produce somewhat lower cost
estimates.
     To the extent that the agency may have underestimated the
extent to which technological innovation and other factors will lead to
future reductions in the costs of video camera-based systems, the
future costs may be even lower than currently expected.
     In view of statutory requirements, the agency is limited
in its ability to reduce the cost of this rulemaking through adjusting
either the requirements or application of the proposed rule or the
schedule for its implementation.
     Congress has mandated the issuance of a final rule instead
of allowing the agency to retain discretion to decide whether to issue
a final rule based on its consideration of all the relevant factors and
information.
     While Congress has not mandated a system that provides the
driver with an image of the area behind his or her vehicle, less
expensive countermeasures, i.e., mirrors and sensors, have thus far
shown very limited effectiveness and thus would not satisfy Congress'
mandate for improving safety.
     Video camera-based systems are by far the most
comprehensive and cost-effective currently available solution for
reducing backover crashes, fatalities and

injuries. As the most cost-effective alternative, a requirement for a
system that provides an image of the area behind the vehicle would be
consistent with the policy preference underlying the Unfunded Mandates
Reform Act.
     The agency is limited by law as to the amount of leadtime
it can provide for this final rule. Were the agency able to provide
even more leadtime than permitted, that additional time might be
sufficient to enable suppliers to develop cheaper cameras. Given the
limits within which the agency must operate, which require the agency
to provide not more than four years of leadtime, the agency has
proposed a back-loaded phase-in schedule, i.e., one focused on the
latter part of the phase-in period, to maximize leadtime.
    As stated above, NHTSA is also considering whether there are any
circumstances under which it would be appropriate and permissible under
the K.T. Safety Act to limit the application of the proposed
requirements to LTVs only, i.e., to exclude passenger cars. The
agency's tentative conclusion is that there are not. If the improved
rear visibility requirements \102\ were applied only to LTVs, we
estimate that the fatalities occurring in backover crashes would still
be reduced by 70 to 83 per year. Similarly, injuries would still be
reduced by 3,284 to 3,888 per year. We estimate that the cost per
equivalent lives for rearview video systems would range from $9.6
million based on a 3% discount rate to $17.0 million based on a 7%
discount rate. Table 18 contrasts the proposal and the alternative
below using a 3% discount rate and 7% discount rate. The table includes
ranges of costs and benefits based on a video camera having a 130- to
180-degree horizontal viewing angle.
---------------------------------------------------------------------------

    \102\ For illustration purposes, figures indicated represent
rear visibility improvement provided using a rearview video system
with 130-degree video camera.

           Table 18--Summary of Estimated Costs and Benefits--3% and 7% Discount Rate Scenarios \103\
----------------------------------------------------------------------------------------------------------------
                                                            Fatalities     Injuries     Net cost per  equivalent
        Applicability                  Total cost            prevented     prevented           life saved
----------------------------------------------------------------------------------------------------------------
Passenger Cars, MPVs, Trucks,  $1.9-2.7 billion..........        95-112   7,072-8,374  $11.8-19.7 million.
 Buses with a GVWR of 10,000
 pounds or less.
MPVs, Trucks, Buses with a     0.8-1.2 billion...........         70-83   3,284-3,888  9.6-17.0 million.
 GVWR of 10,000 pounds or
 less.
----------------------------------------------------------------------------------------------------------------

    Table 19 summarizes the impacts based on a primary estimate which
assumes a 130 degree camera with the display in the rearview mirror, a
low estimate that assumes ultrasonic sensors and auditory warnings, and
a high estimate that assumes a 180 degree camera with the display in
the rearview mirror. Property damage estimates are included in the
costs, and net property damage costs are significantly different (even
in sign) between ultrasonic/radar and any camera system.
---------------------------------------------------------------------------

    \103\ For illustration purposes, figures indicated represent
rear visibility improvement provided using a rearview video system
with 130-degree video camera.

 Table 19--Summary of Benefits and Costs Passenger Cars and Light Trucks (Millions 2007$) MY 2015 and Thereafter
----------------------------------------------------------------------------------------------------------------
                                                           Primary                      High       Discount rate
                                                          estimate    Low estimate    estimate          (%)
----------------------------------------------------------------------------------------------------------------
Benefits:
    Lifetime Monetized................................        $618.6         $37.1        $732.6              7
    Lifetime Monetized................................         777.6          46.7         920.8              3
Costs:
    Lifetime Monetized................................       1,933.3         722.6       2,362.4              7
    Lifetime Monetized................................       1,861.3         730.4       2,296.9              3
Net Benefits:
    Lifetime Monetized................................      -1,314.7        -685.5      -1,629.8              7
    Lifetime Monetized................................      -1,083.7        -683.7      -1,376.1              3
----------------------------------------------------------------------------------------------------------------

VIII. Public Participation

How do I prepare and submit comments?

    Your comments must be written and in English. To ensure that your
comments are correctly filed in the Docket, please include the docket
number of this document in your comments.
    Your comments must not be more than 15 pages long. (49 CFR 553.21).
We established this limit to encourage you to write your primary
comments in a concise fashion. However, you may attach necessary
additional documents to your comments. There is no limit on the length
of the attachments.
    Comments may be submitted to the docket electronically by logging
onto the Docket Management System Web site at http://www.regulations.gov. Follow the online instructions for submitting
comments.
    You may also submit two copies of your comments, including the
attachments, to Docket Management at the address given above under
ADDRESSES.
    Please note that pursuant to the Data Quality Act, in order for
substantive data to be relied upon and used by the agency, it must meet
the information quality standards set forth in the OMB and DOT Data
Quality Act guidelines. Accordingly, we encourage you to consult the
guidelines in preparing your comments. OMB's guidelines may be accessed
at http://www.whitehouse.gov/omb/fedreg/reproducible.html. DOT's
guidelines may be accessed at http://dms.dot.gov.

How can I be sure that my comments were received?

    If you wish Docket Management to notify you upon its receipt of
your comments, enclose a self-addressed,

stamped postcard in the envelope containing your comments. Upon
receiving your comments, Docket Management will return the postcard by
mail.

How do I submit confidential business information?

    If you wish to submit any information under a claim of
confidentiality, you should submit three copies of your complete
submission, including the information you claim to be confidential
business information, to the Chief Counsel, NHTSA, at the address given
above under FOR FURTHER INFORMATION CONTACT. In addition, you should
submit two copies, from which you have deleted the claimed confidential
business information, to Docket Management at the address given above
under ADDRESSES. When you send a comment containing information claimed
to be confidential business information, you should include a cover
letter setting forth the information specified in our confidential
business information regulation. (49 CFR part 512.)

Will the agency consider late comments?

    We will consider all comments that Docket Management receives
before the close of business on the comment closing date indicated
above under DATES. To the extent possible, we will also consider
comments that Docket Management receives after that date. If Docket
Management receives a comment too late for us to consider in developing
a final rule (assuming that one is issued), we will consider that
comment as an informal suggestion for future rulemaking action.

How can I read the comments submitted by other people?

    You may read the comments received by Docket Management at the
address given above under ADDRESSES. The hours of the Docket are
indicated above in the same location. You may also see the comments on