Document ID: NHTSA-2009-0041-0002
Agency: nhtsa
Document Type: Rule
Title: Federal Motor Vehicle Safety Standards: Rearview Mirrors
Posted Date: 2009-03-04T05:00Z

[Federal Register: March 4, 2009 (Volume 74, Number 41)]
[Proposed Rules]               
[Page 9477-9520]
From the Federal Register Online via GPO Access [wais.access.gpo.gov]
[DOCID:fr04mr09-16]                         

[[Page 9477]]

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Part II

Department of Transportation

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National Highway Traffic Safety Administration

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49 CFR Part 571

 Federal Motor Vehicle Safety Standard; Rearview Mirrors; Proposed Rule

[[Page 9478]]

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DEPARTMENT OF TRANSPORTATION

National Highway Traffic Safety Administration

49 CFR Part 571

[Docket No. NHTSA-2009-0041]
RIN 2127-AK43

 
Federal Motor Vehicle Safety Standard; Rearview Mirrors

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

ACTION: Advance notice of proposed rulemaking (ANPRM).

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SUMMARY: This document initiates rulemaking to amend Federal Motor 
Vehicle Safety Standard (FMVSS) No. 111, Rearview Mirrors,\1\ to 
improve a driver's ability to see areas to the rear of a motor vehicle 
in order to mitigate fatalities and injuries associated with backover 
incidents. The agency and Congress are concerned that vehicles have 
``blind zones,'' \2\ areas behind the vehicle in which drivers may have 
difficulty seeing and avoiding a person or other obstacle. Through this 
notice, NHTSA presents its initial research efforts and solicits 
additional information that will enable the agency to develop an 
effective proposal to mitigate backover incidents related to vehicle 
rear blind zones.
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    \1\ 49 CFR 571.111, Standard No. 111, Rearview Mirrors.
    \2\ We note that this is different than what many people 
informally call a ``blind spot,'' a term used to describe an area to 
the side of the car where people may not be able to see a vehicle 
when changing lanes.

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DATES: Comments must be received on or before May 4, 2009.

ADDRESSES: You may submit comments to the docket number identified in 
the heading of this document by any of the following methods:
     Federal eRulemaking Portal: Go to http://
www.regulations.gov. Follow the online instructions for submitting 
comments.
     Mail: Docket Management Facility: U.S. Department of 
Transportation, 1200 New Jersey Avenue, SE., West Building Ground 
Floor, Room W12-140, Washington, DC 20590-0001.
     Hand Delivery or Courier: 1200 New Jersey Avenue, SE., 
West Building Ground Floor, Room W12-140, between 9 a.m. and 5 p.m. ET, 
Monday through Friday, except Federal holidays.
     Fax: 202-493-2251
    Instructions: For detailed instructions on submitting comments and 
additional information on the rulemaking process, see the Public 
Participation heading of the SUPPLEMENTARY INFORMATION section of this 
document. Note that all comments received will be posted without change 
to http://www.regulations.gov, including any personal information 
provided. Please see the Privacy Act heading below.
    Privacy Act: Anyone is able to search the electronic form of all 
comments received into any of our dockets by the name of the individual 
submitting the comment (or signing the comment, if submitted on behalf 
of an association, business, labor union, etc.). You may review DOT's 
complete Privacy Act Statement in the Federal Register published on 
April 11, 2000 (65 FR 19477-78) or you may visit http://
DocketInfo.dot.gov.
    Docket: For access to the docket to read background documents or 
comments received, go to http://www.regulations.gov or the street 
address listed above. Follow the online instructions for accessing the 
dockets.

FOR FURTHER INFORMATION: For technical issues: Ms. Elizabeth Mazzae, 
Vehicle Research and Test Center, Telephone: (937) 666-4511. Facsimile: 
(202) 366-3171. For legal issues: Ari Scott, Office of Chief Counsel, 
Telephone (202) 366-2992. Facsimile: (202) 366-3820. You may send mail 
to these officials at: The National Highway Traffic Safety 
Administration, Attention: NVS-010, 1200 New Jersey Avenue, SE., 
Washington, DC 20590.

SUPPLEMENTARY INFORMATION:

I. Executive Summary
II. Cameron Gulbransen Kids Transportation Safety Act of 2007
III. Existing Regulatory Requirements for Rear Visibility
    A. U.S.
    B. Other Countries
IV. Backover Safety Problem
    A. Injuries and Fatalities in Backing Incidents
    B. Vehicle Type Involvement in Backing Incidents
    C. Age Involvement in Backing Incidents
    D. SCI Backover Case Summary
    E. Assessment of Backover Crash Risk by Pedestrian Location
V. Technologies for Improving Rear Visibility
    A. Rear-Mounted Convex Mirrors
    B. Rearview Video Systems
    C. Sensor-Based Rear Object Detection Systems
    D. Multi-Technology (Sensor + Video Camera) Systems
    E. Future Technologies
    F. Summary and Questions Regarding Technologies for Improving 
Rear Visibility
VI. Drivers' Use and Associated Effectiveness of Available 
Technologies to Mitigate Backovers
    A. Rear-Mounted Convex Mirrors
    B. Rearview Video Systems
    C. Sensor-Based Rear Object Detection Systems
    D. Multi-technology (Sensor + Camera) Systems
    E. Summary
    F. Questions
VII. Rear Visibility of Current Vehicles
VIII. Relationship Between Rear Visibility and Backing/Backover 
Crashes
IX. Options for Mitigating Backover Incidents
    A. Approaches for Improving Vehicles' Rear Visibility
    B. Cost Benefit Scenarios
    C. Questions
X. Options for Measuring a Vehicle's Rear Visibility
    A. Rear Visibility Measurement Procedures
    B. Rear Visibility Measurement Method Variability
    C. Comparison of Human-Based Versus Laser-Based Rear Visibility 
Measurement Protocols
    D. Input From Industry Regarding Rear Visibility Measurement
    E. Questions
XI. Options for Assessing the Performance of Rear Visibility 
Countermeasures
    A. Countermeasure Performance Test Object
    B. Countermeasure Performance Test Area
    C. Countermeasure Performance Test Procedure
    D. Questions
XII. Options for Characterizing Rear Visibility Countermeasures
    A. Options for Display Characteristics
    B. Options for Rearview Video System Camera Characteristics
    C. Questions
XIII. Conclusion
XIV. Public Participation
XV. Rulemaking Analyses and Notices
Appendix A--Methodology for Assessing Backover Crash Risk by 
Pedestrian Location
Appendix B--Method for On-Road Study of Drivers' Use of Rearview 
Video Systems
Appendix C--Details Regarding Development of a Possible 
Countermeasure Application Threshold Based on Rear Blind Zone Area
Appendix D--Results for Analysis of Correlation Between Rear Blind 
Zone Area Measurement Field Size and Backing Crashes

I. Executive Summary

    This advance notice of proposed rulemaking (ANPRM) initiates 
rulemaking to amend Federal Motor Vehicle Safety Standard (FMVSS) No. 
111, Rearview Mirrors, to improve a driver's ability to see areas to 
the rear of a motor vehicle to reduce backover incidents. The agency is 
issuing an ANPRM for two reasons. First, the agency is obligated, 
pursuant to the Cameron Gulbransen Kids Transportation Safety Act of 
2007 (the ``K.T. Safety Act'') Public Law 110-189, February 28, 2008, 
122 Stat. 639, to undertake rulemaking to expand the required field of 
view to enable the driver of a motor vehicle to detect areas

[[Page 9479]]

behind the vehicle to reduce death and injury resulting from backing 
incidents and initiate the rulemaking in a specified time period. 
Second, as there are a wide variety of means to address the problem of 
backover incidents, the National Highway Traffic Safety Administration 
(NHTSA) is interested in soliciting public comment on the current state 
of research and the efficacy of available countermeasures.
    The problem of backovers claims the lives of approximately 292 
people, many of them children every year. A backover is a specifically-
defined type of incident, in which a non-occupant of a vehicle (i.e., a 
pedestrian or cyclist) is struck by a vehicle moving in reverse. Unlike 
most other types of crashes, many backovers occur off public roadways, 
in areas such as driveways and parking lots. Furthermore, a 
disproportionate number of victims of backovers are children under 5 
years old and adults 70 or older. While there are several potential 
reasons for this, children are particularly likely to be missed by 
drivers of rear-moving vehicles because they cannot be seen due to a 
``blind zone'' \3\ in the area directly to the rear of vehicle. In 
addition, children are more likely to move unknowingly into a blind 
zone when the driver does not suspect anyone to be there.
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    \3\ We note that this is different than what many informally 
call a ``blind spot,'' a term used to describe an area to the side 
of the car where people may not be able to see a vehicle when 
changing lanes.
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    NHTSA believes that the problem of backovers warrants an 
appropriate agency action. In response to a Congressional requirement 
of the Safe, Accountable, Flexible, Efficient Transportation Equity 
Act: A Legacy for Users (SAFETEA-LU) \4\, NHTSA has been gathering data 
on backover incidents from a wide variety of sources. Based on this 
research, the agency estimates that on average there are 292 fatalities 
and 18,000 injuries (3,000 of which are judged to be incapacitating) 
resulting from backovers every year. Of those, 228 fatalities and 
17,000 injuries were attributed to backover incidents involving 
passenger vehicles under 10,000 pounds. While all passenger vehicle 
types (cars, sport utility vehicles, pickups, and vans) are involved in 
backover fatalities and injuries, the data indicate that backover 
fatality numbers show pickup trucks (72 of 288) and utility vehicles 
(68 of 228) to be overrepresented when compared to all non-backing 
traffic injury crashes and to their proportion to the passenger vehicle 
fleet. Regardless of the type of vehicle involved, backover incidents 
have garnered significant attention, due to the fact that many have 
involved parents accidentally backing over their own children or 
similar situations. In this notice, NHTSA describes some of the 
research and information-gathering activities it has performed. This 
research centers on four major topic areas.
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    \4\ Safe, Accountable, Flexible, Efficient Transportation Equity 
Act: A Legacy for Users (SAFETEA-LU), Public Law No. 109-59, section 
1109, 119 Stat. 1114, 1168 (2005).
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    The first area involves the nature of backover incidents and 
backing crashes generally. NHTSA has reviewed the details of documented 
backover incidents, including the locations of backover victims, the 
paths the victims took to enter the path of the vehicle, and the 
visibility characteristics of the vehicles involved. This notice 
outlines the information we have about these crashes, whether the lack 
of visibility is playing a significant role, and whether or not the 
characteristics of a class or type of vehicle are a contributing 
factor.
    A second area of focus involves the evaluation of various 
strategies for improving rear visibility. For example, one strategy 
could be to ensure that the vehicles which are over represented in 
terms of fatalities and injuries are improved. Such a strategy would 
focus on pickup trucks or utility vehicles.\5\ Another strategy, could 
seek to establish a minimum blind zone area for vehicles under 10,000 
pounds. Our research indicates that a vehicle's rear blind zone area is 
statistically correlated with its rate of backing crashes.\6\ Using 
this correlation, it may be possible to determine which vehicles most 
warrant rear visibility improvement based on the size of their rear 
blind zones and the setting of a ``threshold''. Possible strategies 
such as these are discussed in this notice and comments are requested.
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    \5\ Fatalities and Injuries in Motor Vehicle Backing Crashes, 
NHTSA Report to Congress (2008).
    \6\ Partyka, S., Direct-View Rear Visibility and Backing Risk 
for Light Passenger Vehicles (2008).
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    The third topic involves the evaluation of various countermeasures. 
NHTSA has consulted past agency research, industry and other outside 
sources, and conducted new research to help determine the costs, 
effectiveness, and limitations of a wide variety of countermeasures. 
Four types of countermeasures are described in this notice, including 
direct vision (i.e., what can be seen by a driver glancing directly out 
a vehicle's windows), rear-mounted convex mirrors, rear object 
detection sensors (such as ultrasonic or radar-based devices), and 
rearview video (RV) systems. While research is ongoing, this notice 
describes how these systems work, how well they perform in identifying 
pedestrians, and how effectively drivers may use them. Where possible, 
we have also included preliminary cost and benefit information. 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 $13.8 to $72.2 million.\7\ For sensors, it 
ranged from $11.3 to $62.5 million. According to our present model, 
none of the systems are cost effective compared to our comprehensive 
cost estimate for a statistical life of $6.1 million.\8\
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    \7\ PRIA, Executive Summary.
    \8\ $6.1 million is the comprehensive value that NHTSA used for 
a statistical life. Further information about this value is 
available in the PRIA published with this notice.
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    A fourth topic involves consideration of technical specifications 
and test procedures that could be used to describe and evaluate the 
performance aspects of direct view, and rear-mounted convex mirrors, 
rear object detection sensors, and rearview video (RV) systems. The 
agency presents preliminary information on potential technical 
specifications and test procedures that we have identified and we want 
to solicit information on how these specifications and procedures 
should be refined for the purposes of developing repeatable compliance 
tests.
    Finally, NHTSA presents a series of questions in this notice. We 
are requesting public input on a variety of areas, including the areas 
described above, studies on the effectiveness of various indirect rear 
visibility systems (i.e., devices that aid a driver in seeing areas 
around a vehicle, such as mirrors or video systems) that have been 
implemented in the U.S. and abroad, or technological possibilities that 
can enhance the reliability of existing technologies. The agency is 
also seeking information on the costs of implementation of all 
available technologies to develop more robust cost and benefit 
estimates.

II. Cameron Gulbransen Kids Transportation Safety Act of 2007

    Subsection (b) of the Cameron Gulbransen Kids Transportation Safety 
Act, directs the Secretary of Transportation to initiate rulemaking to 
amend Federal Motor Vehicle Safety Standard (FMVSS) No. 111, Rearview 
Mirrors, to expand the required field of view to enable the driver of a 
motor vehicle to detect areas behind the motor

[[Page 9480]]

vehicle to reduce death and injury resulting from backing incidents.
    The relevant provisions in subsection (b) are as follows:

    (b) Rearward Visibility--Not later than 12 months after the date 
of the enactment of this Act, the Secretary shall initiate a 
rulemaking to revise Federal Motor Vehicle Safety Standard 111 
(FMVSS 111) to expand the required field of view to enable the 
driver of a motor vehicle to detect areas behind the motor vehicle 
to reduce death and injury resulting from backing incidents, 
particularly incidents involving small children and disabled 
persons. The Secretary may prescribe different requirements for 
different types of motor vehicles to expand the required field of 
view to enable the driver of a motor vehicle to detect areas behind 
the motor vehicle to reduce death and injury resulting from backing 
incidents, particularly incidents involving small children and 
disabled persons. Such standard may be met by the provision of 
additional mirrors, sensors, cameras, or other technology to expand 
the driver's field of view. The Secretary shall prescribe final 
standards pursuant to this subsection not later than 36 months after 
the date of enactment of this Act.
    (c) Phase-In Period--
    (1) PHASE-IN PERIOD REQUIRED--The safety standards prescribed 
pursuant to subsections (a) and (b) shall establish a phase-in 
period for compliance, as determined by the Secretary, and require 
full compliance with the safety standards not later than 48 months 
after the date on which the final rule is issued.
    (2) PHASE-IN PRIORITIES--In establishing the phase-in period of 
the rearward visibility safety standards required under subsection 
(b), the Secretary shall consider whether to require the phase-in 
according to different types of motor vehicles based on data 
demonstrating the frequency by which various types of motor vehicles 
have been involved in backing incidents resulting in injury or 
death. If the Secretary determines that any type of motor vehicle 
should be given priority, the Secretary shall issue regulations that 
specify--
    (A) which type or types of motor vehicles shall be phased-in 
first; and
    (B) the percentages by which such motor vehicles shall be 
phased-in.

    Congress emphasized the protection of small children and disabled 
persons, and added that the revised standard may be met by the 
``provision of additional mirrors, sensors, cameras, or other 
technology to expand the driver's field of view.'' While NHTSA does not 
interpret the Congressional language to necessarily require that all of 
these technologies eventually be integrated into the final requirement, 
we are examining the merits of each of them.

Applicability

    With regard to the scope of vehicles covered by the mandate, the 
statute refers to all motor vehicles less than 10,000 pounds (except 
motorcycles and trailers). This language means that the revised 
regulation would apply to passenger cars, multipurpose passenger 
vehicles, buses, and trucks with a Gross Vehicle Weight Rating (GVWR) 
less than 10,000 lbs.

Statutory Deadline

    The Cameron Gulbransen Kids Transportation Safety Act of 2007 
specified a rapid timeline for development and implementation of this 
rulemaking. Specifically, the Secretary is required to publish a final 
rule within 36 months of the passage of the Act (February 28, 2011). 
Moreover, the agency must initiate rulemaking within 12 months of the 
Act (February 28, 2009). However, it should be noted that under Section 
4 of the Act,\9\ if the Secretary determines that the deadlines 
applicable under this Act cannot be met, the Secretary shall establish 
new deadlines, and notify the Committee on Energy and Commerce of the 
House of Representatives and the Committee on Commerce, Science, and 
Transportation of the Senate of the new deadlines describing the 
reasons the deadlines specified under the Act could not be met.
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    \9\ Cameron Gulbransen Kids Transportation Safety Act of 2007, 
S.694, 110th Cong. section 4 (2007).
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III. Existing Regulatory Requirements for Rear Visibility

    As of today, no country has minimum rear field of view requirements 
for vehicles weighing less than 10,000 lbs. All countries do, however, 
have standards for side and interior rearview mirrors, although 
differences do exist in terms of mirror requirements. No country 
requires rearview video systems or any other type of indirect vision 
device for viewing areas directly behind the vehicle; however, Europe 
does have performance requirements for systems for indirect vision, if 
installed.

A. U.S.

    FMVSS No. 111, Rearview Mirrors establishes requirements for the 
use, field of view, and mounting of motor vehicle rearview mirrors for 
rear visibility.\10\ This standard was enacted in 1976 and applies to 
passenger cars, multipurpose passenger vehicles, trucks, buses, school 
buses and motorcycles. The purpose of this standard is to reduce the 
number of deaths and injuries that occur when the driver of a motor 
vehicle does not have a clear and reasonably unobstructed view to the 
rear. With respect to passenger cars, the standard requires that 
manufacturers mount flat (also referred to as ``plane'' or ``unit 
magnification'') mirrors both inside the vehicle and outside the 
vehicle on the driver's side. The inside mirror must, except as 
specified below, have a field of view at least 20 degrees wide and a 
sufficient vertical angle to provide a view of a level road surface 
extending to the horizon beginning not more than 200 feet (61 m) behind 
the vehicle. In cases where the interior mirror does not meet the 
specified field of view requirements, a plane or convex exterior mirror 
must be mounted on the passenger's side of the car. While a specific 
field of view is not indicated for the passenger-side rearview mirror, 
the driver's side rearview mirror is required to be a plane mirror that 
provides ``the driver a view of a level road surface extending to the 
horizon from a line, perpendicular to a longitudinal plane tangent to 
the driver's side of the vehicle at the widest point, extending 2.4 m 
(7.9 ft) out from the tangent plane 10.7 m (35.1 ft) behind the 
driver's eyes, with the seat in the rearmost position.''
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    \10\ 49 CFR 571.111, Standard No. 111, Rearview mirrors.
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    If a manufacturer uses an interior rearview mirror which meets the 
field of view requirements, and wishes to install an exterior 
passenger-side mirror voluntarily, it may use any type of mirror for 
that purpose. In the case of light trucks, manufacturers may either 
comply with the passenger car requirement or have plane or convex 
outside mirrors with reflective surface area of not less than 126 
square centimeters (19.5 square inches) on each side of the vehicle. 
Reflectance (image brightness) criteria are also established in this 
standard.
    FMVSS No. 111 does not currently establish minimum rear field of 
view requirements for vehicles, nor does it contain minimum 
requirements for indirect vision systems, such as rearview video 
systems. Because of the current absence of a federal regulation of this 
aspect of performance, there is the possibility that there may be 
existing State laws or regulations that regulate the vehicle's rear 
field of view of passenger vehicles.\11\ However, as of this time, 
NHTSA is not aware of any such State laws or regulations. However, we 
request comment on existing or pending State laws or regulations in 
this area, as well as the basis and effect of such regulation, if any 
exist.
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    \11\ See Federalism discussion below in section XV.
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B. Other Countries

ECE
    In 1981, the United Nations Economic Commission for Europe (ECE) 
enacted

[[Page 9481]]

Regulation 46 which details uniform provisions concerning the approval 
of devices for indirect vision.\12\ ECE 46 defines devices for indirect 
vision as those that observe the area adjacent to the vehicle which 
cannot be observed by direct vision, including ``conventional mirrors, 
camera-monitors or other devices able to present information about the 
indirect field of vision to the driver.'' While ECE 46 contains 
specifications for exterior rearview mirrors, it does not, directly 
regulate the rear field of view. Specifications are provided to define 
the required minimum size of the interior rearview mirror's surface 
area, but not its field of view. This regulation applies to all power-
driven vehicles with at least four wheels that are used for the 
carriage of people or goods, and vehicles with less than four wheels 
that are fitted with bodywork which partly or wholly encloses the 
driver.
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    \12\ ECE 46-02, Uniform Provisions Concerning the Approval of: 
Devices for Indirect Vision and of Motor Vehicles with Regard to the 
Installation of these Devices, (August 7, 2008).
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    ECE 46 requires driver and passenger ``flat'' side rearview mirrors 
as found in FMVSS No. 111. ECE 46 differs from FMVSS No. 111 in that it 
also permits wide-angle convex mirrors on the driver's side of the 
vehicle for all classes of vehicles except for certain vehicles over 
7.5 tons, for which they are required.
    The ECE 46 regulation also outlines requirements for devices for 
indirect vision other than mirrors for vehicles with more than eight 
seating positions and those configured for refuse collection. 
Specifically, it contains a general requirement that camera-monitor 
devices, if present, shall perceive a visible spectrum and shall always 
render this image without the need for interpretation into the visual 
spectrum. The device's visual display is required to be located 
approximately in the same direction as the interior rearview mirror. 
The monitor is required to render a minimum contrast under various 
light conditions as specified by International Organization for 
Standardization (ISO) 15008:2003 \13\ and have an adjustable luminance 
level. The regulation also defines detection distance, the distance 
measured at ground level from the eye point to the extreme point at 
which a critical object can be perceived, as an aspect of camera-
monitor device performance.
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    \13\ ISO 15008:2003 Road vehicles--Ergonomic aspects of 
transport information and control systems--Specifications and 
compliance procedures for in-vehicle visual presentation.
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    A January 2008 amendment to ECE Regulation 46 required that a 
camera-monitor system must display to the driver a flat horizontal 
portion of the road directly behind the vehicle from the rear bumper 
outward to a distance of 2000 mm (6.6 ft). It further specified that if 
an indirect vision device other than a camera-monitor is used, a test 
object 50 cm (19.7 in) in height and 30 cm (11.8 in) in diameter must 
be visible in the specified area. However, in a later amendment of 
UNECE 46 (dated August 7, 2008) this requirement was removed and 
replaced with the statement, ``Vehicles may be equipped with additional 
devices for indirect vision.'' \14\ This change allows for indirect 
vision systems to be installed on European vehicles without meeting any 
performance requirements.
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    \14\ Section 15.3.5 of ECE 46-02, Uniform Provisions Concerning 
the Approval of: Devices for Indirect Vision and of Motor Vehicles 
with Regard to the Installation of these Devices, (August 7, 2008).
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Canada
    Canada has rearview mirror requirements that are essentially 
identical to those in the U.S. All passenger cars are required to have 
a driver's-side outside rearview mirror. Passenger cars are also 
required to be equipped with an interior rearview mirror providing 
``the driver with a field of view to the rear that is not less than 20 
degrees measured horizontally rearward from the projected eye point and 
extends to the horizon and includes a point on the road surface not 
more than 60 m (200 feet) directly behind the vehicle.'' If the 
interior rearview mirror does not meet these requirements, a side 
rearview mirror must be mounted on the passenger side of the vehicle 
opposite the driver's side.
Japan
    Japanese regulation, Article 44, provides a performance based 
requirement for rearview mirrors.\15\ For light vehicles, rearview 
mirrors must be present that enable drivers to check the traffic 
situation around the left-hand lane edge and behind the vehicle from 
the driver's seat.\16\ The regulation requires that the driver be able 
to ``visually confirm the presence of a cylindrical object 1 m high and 
0.3 m in diameter (equivalent to a 6-year-old child) adjacent to the 
front or the left-hand side of the vehicle (or the right-hand side in 
the case of a left-hand drive vehicle), either directly or indirectly 
via mirrors, screens, or similar devices.'' Article 44 does not specify 
requirements for rear-mounted convex mirrors and rearview video 
systems, therefore these devices are allowed, but not required under 
the standard. Rear-mounted convex mirrors are commonly used as backing 
aids on sport utility vehicles (SUVs) and vans in Japan; however, NHTSA 
is not aware of research documenting the effectiveness of these mirrors 
in mitigating backover crashes.
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    \15\ Japanese Safety Regulation Article 44 and attachments 79-
81.
    \16\ Vehicles manufactured for the Japanese market are right-
hand drive.
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Korea
    The Korean regulation on rearview mirrors, Article 50,\17\ outlines 
rearview mirror requirements for a range of vehicles. Article 50 
requires a flat or convex exterior mirror mounted on the driver's side 
for passenger vehicles and buses with less than 10 passengers. For 
buses, cargo vehicles, and special motor vehicles, flat or convex rear-
view mirrors are required on both sides of the vehicle. Article 50 does 
not address rear-mounted convex mirrors and rearview video systems, 
therefore these devices are allowed, but not required under the 
standard. Again, rear-mounted convex mirrors are commonly used as 
backing aids on SUVs and vans in Korea; however, NHTSA is not aware of 
research documenting the effectiveness of these mirrors in mitigating 
backover crashes.
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    \17\ Korean Safety Regulation Article 50.
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IV. Backover Safety Problem

    Based on our information to date, NHTSA has found that the problem 
of backovers claims the lives of hundreds of people every year. NHTSA 
defines backover as a specifically-defined type of incident, in which a 
non-occupant of a vehicle (i.e., a pedestrian or cyclist) is struck by 
a vehicle moving in reverse. However, because many backovers occur off 
public roadways, in areas such as driveways and parking lots, NHTSA's 
ordinary methodologies for collecting data as to the specific numbers 
and circumstances of backover incidents have not always given the 
agency a complete picture of the scope and circumstances of these types 
of incidents. The following sections detail NHTSA's attempts to both 
quantify the number of backover incidents and determine their nature.

A. Injuries and Fatalities in Backing Incidents

    In response to SAFETEA-LU Sections 2012 and 10305, NHTSA developed 
the Not in Traffic Surveillance (NiTS) system to collect information 
about all nontraffic crashes, including nontraffic backing crashes. 
NiTS provided information on these backing crashes

[[Page 9482]]

that occurred off the traffic way and which were not included in 
NHTSA's Fatality Analysis Reporting System (FARS) or the National 
Automotive Sampling System--General Estimates System (NASS-GES). The 
subset of backing crashes that involve a pedestrian, bicyclist, or 
other person not in a vehicle, is referred to as ``backovers.'' This is 
distinguished from the larger category of ``backing crashes,'' which 
would include such non-backover events such as a vehicle going in 
reverse and colliding with another vehicle, or a vehicle backing off an 
embankment or into a stationary object. While the primary purpose of 
this rulemaking is to prevent backovers, any technology that improves 
rear visibility should have a positive effect on backing crashes in 
general.
    Based on 2002-2006 data from FARS and NASS-GES, and 2007 data from 
NiTS, NHTSA estimates that 463 fatalities and 48,000 injuries a year 
occur in traffic and nontraffic backing crashes.\18\ Most of these 
injuries are minor injuries, but an estimated 6,000 per year are 
incapacitating injuries. Overall, an estimated 65 percent (302) of the 
fatalities and 62 percent (29,000) of the injuries in backing crashes 
occurred in nontraffic situations.
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    \18\ Fatalities and Injuries in Motor Vehicle Backing Crashes, 
NHTSA Report to Congress (2008).
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    With regard to injuries and fatalities related specifically to 
backovers, these account for an estimated 63 percent (292) of the 
fatalities and 38 percent (18,000) of the injuries in backing crashes 
for all vehicles (cars, light trucks or vans, heavy trucks, and other/
multiple vehicles). Other backing crash scenarios account for an 
estimated 171 fatalities (37 percent) and 30,000 injuries (62 percent) 
per year. Table 1 shows the fatalities and injuries in all backing 
crashes. Table 1 also demonstrates that backover victims tend to be 
more seriously injured than individuals in other backing crashes (i.e., 
non-backover crash incidents). In fact, more than half (10,000 of 
18,000) of the injuries in backovers are more severe than possible 
(minor) injuries.

         Table 1--Annual Estimated Fatalities and Injuries in All Backing Crashes for All Vehicles \19\
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          Injury severity                     Total                   Backovers           Other backing crashes
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                                     Estimated      Sample     Estimated      Sample     Estimated      Sample
                                       total        count        total        count        total        count
----------------------------------------------------------------------------------------------------------------
Fatalities........................          463        1,610          292          716          171          894
Incapacitating Injury.............        6,000          304        3,000          131        3,000          173
Non-incapacitating Injury.........       12,000          813        7,000          372        5,000          441
Possible Injury...................       27,000          929        7,000          179       20,000          750
Injured Severity Unknown..........        2,000           48        1,000           23        2,000           25
                                   -----------------------------------------------------------------------------
    Total Injuries................       48,000        2,094       18,000          705       30,000       1,389
----------------------------------------------------------------------------------------------------------------
Source: FARS 2002-2006, NASS-GES 2002-2006, NiTS 2007.
Note: Estimates may not add up to totals due to independent rounding.

B. Vehicle Type Involvement in Backing Incidents
---------------------------------------------------------------------------

    \19\ Id.
---------------------------------------------------------------------------

    Most backover fatalities and injuries involve passenger vehicles. 
As indicated in Table 2, 78 percent of the backover fatalities and 95 
percent of the backover injuries involved passenger vehicles. An 
estimated fifteen percent (68) of the backing crash fatalities occur in 
multivehicle crashes, and an estimated thirteen percent (62) occur in 
single-vehicle non-collisions such as occupants who fall out of and are 
struck by their own backing vehicles. About half of the backing crash 
injuries (20,000 per year) occur in multivehicle crashes involving 
backing vehicles. Table 3 indicates that all major passenger vehicle 
types (cars, utility vehicles, pickups, and vans) are involved in 
backover fatalities and injuries. However, the data indicate that some 
vehicles may have a greater risk of involvement in backing crashes than 
other vehicles. Table 3 illustrates that pickup trucks and utility 
vehicles are overrepresented in backover fatalities when compared to 
all non-backing traffic injury crashes and to their proportion to the 
passenger vehicle fleet.

              Table 2--Injuries and Fatalities and Injuries by Backing Crash Type for All Vehicles
----------------------------------------------------------------------------------------------------------------
                                                                    All vehicles           Passenger vehicles
                   Backing crash scenarios                   ---------------------------------------------------
                                                               Fatalities    Injuries    Fatalities    Injuries
----------------------------------------------------------------------------------------------------------------
Backovers: Striking Nonoccupant.............................          292       18,000          228       17,000
Backing: Striking Fixed Object..............................           33        2,000           33        2,000
Backing: Noncollision.......................................           62        1,000           53        1,000
Backing: Striking/Struck by Other Vehicle...................           68       24,000           39       20,000
Backing: Other..............................................            8        3,000            8        3,000
                                                             ---------------------------------------------------
    Total Backing...........................................          463       48,000          361       43,000
----------------------------------------------------------------------------------------------------------------

[[Page 9483]]

                   Table 3--Passenger Vehicle Backover Fatalities and Injuries by Vehicle Type
----------------------------------------------------------------------------------------------------------------
                                                                                             Percent
                                                                                                of
                                                                                 Estimated   vehicles
                                                        Percent of   Estimated    percent    in non-    Percent
           Backing vehicle type             Fatalities                injuries       of      backing    of fleet
                                                        fatalities                injuries   traffic
                                                                                              injury
                                                                                             crashes
----------------------------------------------------------------------------------------------------------------
Car.......................................          59          26        9,000         54         62         58
Utility Vehicle...........................          68          30        3,000         20         14         16
Van.......................................          29          13        1,000          6          8          8
Pickup....................................          72          31        3,000         18         15         17
Other Light Vehicle.......................           0           0            *          2          1         <1
Passenger Vehicles........................         228         100       17,000        100        100       100
----------------------------------------------------------------------------------------------------------------
Source: FARS 2002-2006, NASS-GES 2002-2006, NiTS 2007.
Note: * indicates estimate less than 500, estimates may not add up to totals due to independent rounding.

C. Age Involvement in Backing Incidents

    Table 4 contains the age of the backover victim for fatalities and 
injuries for all backovers as well as backovers involving passenger 
vehicles. Table 4 also details the proportion of the United States 
(U.S.) population in each age category from the U.S. Census Bureau's 
Population Estimates Program for comparison. Similar to previous 
findings, backover fatalities disproportionately affect children under 
5 years old and adults 70 or older. When restricted to backover 
fatalities involving passenger vehicles, children under 5 account for 
44 percent of the fatalities, and adults 70 and older account for 33 
percent. The difference in the results between all backovers and 
passenger vehicle backovers occurs because large truck backovers, which 
are excluded from the passenger vehicle calculations, tend to affect 
adults of working age.

                         Table 4--All Backover Fatalities and Injuries by Age of Victim
----------------------------------------------------------------------------------------------------------------
                                                                               Estimated
                                                      Percent of   Estimated    percent     Sample    Percent of
              Age of victim               Fatalities                injuries       of      count of   population
                                                      fatalities                injuries   injuries
----------------------------------------------------------------------------------------------------------------
All Vehicles:
    Under 5.............................         103          35        2,000          8         37            7
    5-10................................          13           4            *          3         33            7
    10-19...............................           4           1        2,000         12         75           14
    20-59...............................          69          24        9,000         48        383           55
    60-69...............................          28           9        2,000          8         54            8
    70+.................................          76          26        3,000         18        107            9
    Unknown.............................  ..........  ..........            *          2         16  ...........
                                         -----------------------------------------------------------------------
        Total...........................         292         100       18,000        100        705          100
Passenger Vehicles:
    Under 5.............................         100          44        2,000          9         35            7
    5-10................................          10           4        1,000          3         30            7
    10-19...............................           1           1        2,000         12         71           14
    20-59...............................          29          13        8,000         46        319           55
    60-69...............................          15           6        1,000          8         46            8
    70+.................................          74          33        3,000         19         95            9
    Unknown.............................  ..........  ..........            *          2         12  ...........
                                         -----------------------------------------------------------------------
        Total...........................         228         100       17,000        100        608         100
----------------------------------------------------------------------------------------------------------------
Source: U.S. Census Bureau, Population Estimates Program, 2007 Population Estimates; FARS 2002-2006, NASS-GES
  2002-2006, NiTS 2007.

    The proportion of backover injuries by age group is more similar to 
the proportion of the population than for backover fatalities. However, 
while children under 5 years old appear to be slightly overrepresented 
in backover injuries compared to the population, adults 70 and older 
appear to be greatly overrepresented. One reason for the relatively 
large proportion of injuries in backover crashes among older adults may 
be that backovers involving younger nonoccupants may not result in an 
injury while the same backover involving an older nonoccupant may 
result in a fall and a broken bone.
    Table 5 presents passenger vehicle backover fatalities by year of 
age for victims less than 5 years old. Out of all backover fatalities 
involving passenger vehicles, 26 percent (60 out of 228) of victims are 
1 year of age and younger.

[[Page 9484]]

    Table 5--Breakdown of Backover Fatalities and Injuries Involving
            Passenger Vehicles for Victims Under Age 5 Years
------------------------------------------------------------------------
                                                              Number of
                   Age of victim (years)                      fatalities
------------------------------------------------------------------------
0..........................................................           <1
1..........................................................           59
2..........................................................           23
3..........................................................           14
4..........................................................            3
                                                            ------------
    Total..................................................         100
------------------------------------------------------------------------
Note: Estimates may not add to totals due to independent rounding.
Source: U.S. Census Bureau, Population Estimates Program, 2007
  Population Estimates; FARS 2002-2006, NASS-GES 2002-2006, NiTS 2007.

D. Special Crash Investigation Backover Case Summary

    In addition to collecting police-reported backovers through NHTSA's 
data collection infrastructure, NHTSA's efforts to understand backover 
incidents have included a Special Crash Investigation (SCI) program. 
The SCI program was created to examine the safety impact of rapidly 
changing technologies and to provide NHTSA with early detection of 
alleged or potential vehicle defects.
    SCI began investigating cases related to backovers in October 
2006.\20\ SCI receives notification of potential backover cases from 
several different sources including media reports, police and rescue 
personnel, contacts within NHTSA, reports from the general public, as 
well as notifications from the NASS. As of July 1, 2008, SCI had 
received a total of 52 notifications from a combination of all sources 
regarding backovers.\21\ For the purpose of the SCI cases, an eligible 
backover was defined as a light passenger vehicle where the back plane 
strikes or passes over a person who is either positioned to the rear of 
the vehicle or is approaching from the side. SCI primarily focuses on 
cases involving children; however, it investigates some cases involving 
adults. The majority of notifications received do not meet the criteria 
for case assignment. Typically the reasons for not pursuing further 
include:
---------------------------------------------------------------------------

    \20\ Fatalities and Injuries in Motor Vehicle Backing Crashes, 
NHTSA Report to Congress (2008).
    \21\ Since SCI investigates as many relevant cases that they are 
notified about as possible and not on a statistical sampling of 
incidents, results are not representative of the general population.
---------------------------------------------------------------------------

    [cir] The reported crash configuration is outside of the scope of 
the program,
    [cir] Minor incidents with no fatally or seriously injured persons, 
or
    [cir] Incidents where cooperation can not be established with the 
involved parties.
    As an example, many reported incidents are determined to be side or 
frontal impacts, which exclude them from the program. NHTSA requests 
that commenters submit any other existing backover incident data that 
could aid in providing a clearer picture of the range of backover 
accidents.
    The SCI effort to examine backover crashes includes an on-site 
inspection of the scene and vehicle, as well as interviews of the 
involved parties when possible. When an on-site investigation is not 
possible, backover cases are investigated remotely through an 
examination of police-provided reports and photos as well as interviews 
with the involved parties. For each backover case investigated, a case 
vehicle visibility study is also conducted to determine the vehicle's 
blind zones and also to determine at what distance behind the vehicle 
the occupant may have become visible to the driver.
    Through July 2008, NHTSA had completed special crash investigations 
of 52 backover cases.\22\ The 52 backing vehicles were comprised of 17 
passenger cars, 21 sport utility vehicles, and 14 pickup trucks. Only 4 
of the cases (8 percent) contained vehicles equipped with a backup or 
parking aid. Eighty-eight percent of the backover crashes (46 of the 
52) involved children, ranging in age from less than 1 year old up to 
13 years old, who were struck by vehicles. Adults were generally 
excluded from the study unless they were seriously injured or killed or 
if the backing vehicles were equipped with backing or parking aids. A 
total of 6 cases were investigated involving struck adults. Of the 52 
backover cases, exactly half (26) involved fatally injured 
nonoccupants.
---------------------------------------------------------------------------

    \22\ The data obtained for the SCI cases cited in this report 
are based on preliminary case information. Data are subject to 
change based on final investigative findings.
---------------------------------------------------------------------------

    A breakdown of the victim's path of travel prior to being struck is 
as follows: 24 were approaching from the right or left of the vehicle, 
19 were stationary behind the vehicle, 10 were unknown, and one was 
``other.'' \23\
---------------------------------------------------------------------------

    \23\ Note that one or more cases examined involved multiple 
victims, causing the total of the path breakdown scenarios to be 53 
rather than 52.
---------------------------------------------------------------------------

E. Assessment of Backover Crash Risk by Pedestrian Location

    NHTSA believes it would be helpful to know whether and to what 
degree the pedestrian's location at the start of a vehicle's backing 
plays a part in the likelihood of the pedestrian being struck. As such, 
NHTSA used data from a recent NHTSA study of drivers' backing behavior 
\24\ to estimate the relative risk of a pedestrian colliding with a 
vehicle during a backing maneuver.
---------------------------------------------------------------------------

    \24\ 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.
---------------------------------------------------------------------------

    A Monte Carlo simulation was used to calculate a probability-based 
risk weighting for a test area centered behind the vehicle. The 
probability-based risk weightings for each grid square were based on 
the number of pedestrian-vehicle backing crashes predicted by the 
simulation for trials for which the pedestrian was initially (i.e., at 
the time that the vehicle began to back up) in the center of one square 
of the grid of 1-foot squares. A total of 1,000,000 simulation trials 
were run with the pedestrian initially in the center of each square. 
Additional details about assumptions relating to the vehicle and 
pedestrian, as well as the simulation, are presented in Appendix A.
    Figure 1 summarizes the calculated relative crash risk for each 
grid square. Note that the white shaded area does not have a zero 
backover risk; it merely has a low (less than 15 percent of the 
maximum) risk. This analysis shows that the probability of crash 
decreases rapidly as the pedestrian's initial location is moved back, 
further away, from the rear bumper of the vehicle. There are 
substantial side lobes, giving pedestrians some risk of being hit even 
though they were not initially directly behind the vehicle. The results 
suggest that coverage of an area 12 feet wide by 36 feet long centered 
behind the vehicle would address pedestrian locations having relative 
crash risks of 0.15 and higher. To address crash risks of 0.20 and 
higher, an area 7 feet wide and 33 feet long centered behind the 
vehicle would need to be covered. NHTSA seeks comment on the coverage 
area that is needed to establish a reasonable safety zone behind the 
vehicle.
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V. Technologies for Improving Rear Visibility

    Since the early 1990s, NHTSA has actively researched approaches to 
mitigate backing crashes for heavy and light vehicles by assessing the 
effectiveness of various backing aid technologies. In recent years, 
manufacturers have added object detection sensors and video cameras to 
vehicles to aid drivers in performing backing maneuvers. According to 
Ward's 2008 Automotive Yearbook, backing aids utilizing sensors and/or 
video cameras were installed in approximately 14 percent of model year 
2007 light vehicles.\25\ While these systems are becoming increasingly 
available, they have typically been marketed as parking aids to help 
drivers detect and avoid obstacles in low-speed backing scenarios.
---------------------------------------------------------------------------

    \25\ 2008 Ward's Automotive Yearbook.
---------------------------------------------------------------------------

    To assess whether or not these systems could also be used to detect 
pedestrians, the agency has, and continues to, evaluate them. The 
agency has also evaluated rear-mounted convex mirrors and rearview 
video systems. In the following sections, we outline the technologies 
we have evaluated, research conducted by the agency and others, and 
offer our preliminary observations on how they would meet the 
Congressional directive to improve the rear visibility of current 
vehicles.

A. Rear-Mounted Convex Mirrors

Description
    Rear-mounted convex mirrors are mirrors with a curved reflective 
surface thereby providing a wider field of view than plane (i.e., flat) 
mirrors. These mirrors can be mounted at the upper center of the rear 
window with the reflective surface pointing at the ground (commonly 
referred to as backing mirrors, under mirrors, or ``look-down'' 
mirrors), the driver's side upper corner of the vehicle (commonly seen 
on delivery vans or mail delivery trucks and called ``corner 
mirrors''), or integrated into the inside face of both rearmost pillars 
(called ``cross-view'' mirrors). While center or corner-mounted convex 
rearview mirrors show the driver an area behind the vehicle, rear 
cross-view mirror pairs are intended to aid a driver when backing into 
a right-of-way by showing objects approaching on a perpendicular path 
behind the vehicle.
    To view the area behind a vehicle, interior rear-mounted convex 
mirrors can be viewed directly by the driver, if in his direct line of 
sight, or they may be looked at indirectly by viewing their reflection 
in the interior or exterior rearview mirror. In the case of a rear 
``look-down mirror,'' the driver can either glance rearward directly at 
this mirror, or view its reflection in the interior rearview mirror. 
For a rear convex corner mirror, the driver must look into the driver's 
side (i.e., exterior) rearview mirror to view the reflection of the 
rear convex corner mirror. In the case of rear cross-view mirrors, they 
can be viewed directly by the driver or indirectly by viewing their 
reflection in the interior rearview mirror.
    In the U.S., rear-mounted convex mirrors are sometimes seen on 
delivery trucks and vans. Rear-mounted convex mirrors are primarily 
available as aftermarket products in the U.S., but are also available 
as original equipment on one sport utility vehicle.\26\ In Korea and 
Japan, rear-mounted convex mirrors are used on small school buses, 
short delivery trucks, and some multipurpose vehicles (e.g., SUVs) to 
allow drivers to view areas behind a vehicle.
---------------------------------------------------------------------------

    \26\ Rear cross-view mirrors have been available on the Toyota 
4Runner base model vehicles since MY 2003.
---------------------------------------------------------------------------

    While rear convex cross-view mirrors are available as aftermarket 
products that mount to the inside of the rear window for all passenger 
car body types, this is not the case for look down mirrors. Rear convex 
look-down or corner convex mirrors need to have a rear window that is 
vertically aligned with the rear of the vehicle (such as a station 
wagon, SUV or van) in order to have a clear view of the area behind the 
vehicle.
Research
    NHTSA has conducted research on rear-mounted convex mirrors for use 
on medium straight trucks and to a limited extent, passenger vehicles 
(i.e., cars, trucks, vans, SUVs). The research and how its results may 
be related to the improvement of rear visibility are discussed below.
Passenger Vehicle Research
    In response to Section 10304 of the Safe, Accountable, Flexible, 
Efficient Transportation Equity Act: A Legacy for Users (SAFETEA-
LU),\27\ NHTSA conducted a study to evaluate methods to reduce the 
incidence of injury, death, and property damage caused by backing 
collisions of passenger vehicles.\28\ The examination of two convex 
mirror systems revealed that pedestrians and objects were not visible 
in some areas directly behind the vehicle (this area could be described 
as the area bounded by the vertical planes formed by the sides of the 
vehicle, and extending rearward). The research also found that the 
convexity of the mirrors caused significant image distortion, and 
reflected objects were difficult to discern. It is unknown if this 
issue can be addressed in future designs. For the tested designs, 
concentrated glances were necessary to identify the nature of rear 
obstacles; it is not known if a driver making quick glances prior to 
initiating a backing maneuver would allocate sufficient time to allow 
recognition of an obstacle or pedestrian shown in the mirror.
---------------------------------------------------------------------------

    \27\ SAFETEA-LU, Sec. 1109, 119 Stat. 1168.
    \28\ 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.
---------------------------------------------------------------------------

Current Mirror Research
    NHTSA is currently evaluating the image quality (distortion and 
minification) and field of view of rear-mounted convex mirrors. The 
mirror types being examined include an aftermarket rear convex look-
down mirror, aftermarket rear corner convex mirror, aftermarket rear 
convex cross-view mirrors designed for SUVs and passenger cars (e.g., 
sedans, coupes), and original equipment rear convex cross-view mirrors 
on a 2003 Toyota 4Runner.
    Figure 2 below illustrates the types of measurements that NHTSA 
plans to collect to evaluate the image quality and field of view for 
rear convex mirrors. As illustrated in the Figure, using a test device 
that simulates a 1-year-old child, the rear convex look-down mirror 
shows an area directly behind a vehicle (a 2007 Honda Odyssey minivan) 
but beyond 15 feet from the bumper, the image could not be discerned.
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[[Page 9488]]

    Using the same 1-year-old child-sized test device, Figure 3 
illustrates the measured field of view for an exemplar rear convex 
cross-view mirror system. The area behind the vehicle cannot be seen, 
rather, only the area that extends outward from both rear corners of 
the vehicle.
[GRAPHIC] [TIFF OMITTED] TP04MR09.002

    NHTSA previously evaluated the quality of images displayed by a 
rear corner convex mirror mounted on a 1996 Grumman-Olsen step van with 
a 12-foot long box.\29\ Using those data, an analysis was performed in 
which linear extrapolation and two-dimensional interpolation \30\ were 
applied to estimate at which of four locations behind the vehicle a 1-
year-old child dummy (i.e., anthropomorphic test device, or ATD) could 
be visible to a driver using a rear corner convex mirror. The four 
locations assessed are labeled A through D in Figure 4.
---------------------------------------------------------------------------

    \29\ Mazzae, E.N., and Garrott, W.R., Experimental Evaluation of 
the Performance of Available Backover Prevention Technologies for 
Medium Straight Trucks, NHTSA Technical Report No. DOT HS 810 865, 
November 2007.
    \30\ Measured minutes of arc subtended by the test object were 
first linearly extrapolated to estimate the effects of differences 
in the distance from the driver eyepoint to the side rearview mirror 
and the distance from the side rearview mirror to the rear corner 
convex mirror. Two-dimensional linear interpolation was then used to 
correct for reducing the vehicle width from the 7.0 feet for the 
step van to the 6.0 feet more typical of light passenger vehicle and 
for estimating minutes of arc subtended at the four locations, A 
through D. Note that estimates based upon multiple multi-linear 
extrapolation/interpolation were made because they could be done 
quickly using data that NHTSA had previously collected.

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

[[Page 9489]]

[GRAPHIC] [TIFF OMITTED] TP04MR09.003

    The reflected image of the 1-year-old dummy becomes less minified 
and is easier for the driver to discern as the location of the dummy 
moves either forward towards the rear bumper of the vehicle or 
laterally towards the driver's side of the vehicle. Therefore, for a 
vehicle for which the dummy is visible at Point A, the dummy is 
expected to be visible anywhere across the entire width of the vehicle 
for distances up to at least 10 feet from the vehicle's rear bumper.
    Estimated visibility of the 1-year-old dummy for each of the four 
locations (identified in Figure 4) for 9 vehicles is shown in Table 6.

                                  Table 6--Visibility of a 1-Year-Old Child Dummy Using a Corner Rear Cross-View Mirror
--------------------------------------------------------------------------------------------------------------------------------------------------------
              Year                       Make                Model         Can see Point A?    Can see Point B?    Can see Point C?    Can see Point D?
--------------------------------------------------------------------------------------------------------------------------------------------------------
2008............................  Chevrolet.........  Express...........  No................  No................  No................  Yes.
2003............................  Volvo.............  XC90..............  No................  No................  Yes...............  Yes.
2005............................  Nissan............  Armada............  No................  No................  No................  Yes.
2007............................  Saturn............  Vue...............  No................  No................  Yes...............  Yes.
2007............................  Jeep..............  Commander.........  No................  No................  Yes...............  Yes.
2008............................  Toyota............  Highlander........  No................  No................  Yes...............  Yes.
2007............................  Ford..............  Edge..............  No................  No................  Yes...............  Yes.
2005............................  Chevrolet.........  Uplander..........  No................  No................  No................  Yes.
2003............................  Toyota............  4Runner...........  No................  No................  Yes...............  Yes.
--------------------------------------------------------------------------------------------------------------------------------------------------------

[[Page 9490]]

    As the table indicates, it is not expected that a driver could see 
the 1-year-old dummy when the dummy is located directly behind the 
passenger's side of the vehicle at a distance of 6 or 10 feet back from 
the vehicle's rear bumper. The quality of the reflected image is better 
on the vehicle's centerline, with the dummy expected to be visible for 
six out of nine vehicles when it is located 10 feet back from the rear 
bumper and visually discernable to the driver for all nine vehicles 
when it is only 6 feet aft of the rear bumper.
    This mirror research is scheduled to be completed in 2009 and will 
be summarized in a published NHTSA report thereafter. Along with 
comments received to this notice, NHTSA hopes to use this research 
information in the development of a proposal.
Observations
    Some advantages of rear-mounted convex mirrors include that when 
compared to video cameras and object detection sensors, they are 
relatively inexpensive (e.g., less than $40 retail as an aftermarket 
product) and have the potential to last the life of the vehicle. They 
also provide a wider field of view than that provided by plane mirrors. 
However, they also possess inherent disadvantages. In general, convex 
mirrors compress (i.e., minify) and distort the image of reflected 
objects in their field of view. This image distortion and image 
minification make objects and pedestrians appear very narrow and 
difficult for the driver to discern and identify. These aspects of 
image quality worsen as the length of the vehicle increases.
    Rear cross-view mirrors are positioned to show an area to the side 
and rear of the vehicle but they do not provide a good view of the area 
directly behind the vehicle (the area bounded by two imaginary planes 
tangent to the sides of the vehicle. As such, a pedestrian or object in 
this area could be invisible to the driver. They can however, help 
drivers see objects approaching the rear of the vehicle along a 
perpendicular path. NHTSA is aware that single rear convex look-down 
mirrors are commonly found on SUVs and vans in Korea and Japan. 
However, we are unaware of any publicly available studies that have 
been conducted to assess the effectiveness of these mirrors in 
improving rear visibility. We seek comment on the availability of any 
such studies.

B. Rearview Video Systems

Description
    A growing number of vehicles in the U.S. are equipped with rearview 
video systems. These systems can permit a driver to see much of the 
area behind the vehicle via a video display showing the image from a 
video camera mounted on the rear of the vehicle. The images may be 
presented to the driver using an existing screen in the vehicle, such 
as a navigation system or multifunction display screen, or by adding a 
display incorporated into the dashboard or interior rearview mirror.
    Costs for these rearview video systems are estimated at 
approximately $58-$88 for vehicles equipped with a navigation system or 
other type of multi-function visual display, to $158-$189 for vehicles 
requiring a dashboard-mounted display screen, or $173-$203 for vehicles 
with an RV display integrated into the interior rearview mirror.\31\
---------------------------------------------------------------------------

    \31\ PRIA, section VI.
---------------------------------------------------------------------------

Research
    Recent research on rearview video systems conducted by NHTSA and 
our observations about the research are presented below.
NHTSA Testing in Support of SAFETEA-LU
    In response to Section 10304 of SAFETEA-LU, NHTSA examined three 
rearview video systems (RV): One in combination with original equipment 
rear parking sensors, one aftermarket system combining both RV and 
parking sensor technologies, and one original equipment RV system.\32\ 
This examination of RV systems included assessment of their field of 
view and their potential to provide drivers with information about 
obstacles behind the vehicle.
---------------------------------------------------------------------------

    \32\ 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.
---------------------------------------------------------------------------

    Through this study, the agency made the following observations. The 
rearview video systems examined provided a clear image of the area 
behind the vehicle in daylight and indoor lighting conditions. RV 
systems displayed images of pedestrians or obstacles behind the vehicle 
to a substantial range of 23 feet or more, except for an area within 8-
12 inches of the rear bumper at ground level. Beyond the rear bumper, 
the rearview video systems also displayed areas wider than 50 feet.
    The location and angle at which the rearview video camera is 
mounted on the back of the vehicle affects the size of the field of 
view provided by the system. The longitudinal range of the images 
displayed by the two original equipment RV systems tested differed 
significantly. One rearview video system's camera presented an image 
having a limited vertical angle, resulting in a substantially shorter 
longitudinal range along the centerline of the vehicle (ending at 
approximately 23 feet from the rear bumper at ground level). For a 3-
year-old child dummy centered 2 feet behind the vehicle, the shorter 
visible range exhibited by this particular RV system caused the top of 
the dummy's head to be out of view.
Observations
    We found that RV systems can display areas on the ground almost 
directly adjacent to the bumper of the vehicle. Furthermore, RV systems 
offer the possibility of a wide field of view, with some systems able 
to show 180 degrees behind the vehicle.
    However, during the short course of testing, NHTSA also noted some 
operational issues with video camera performance in certain weather 
conditions, such as rain and snow. For example, rain drops and the 
buildup of ice on the video camera lens can significantly reduce the 
quality of the view provided by the RV system. Also, in evaluating 
these technologies we have not had the opportunity to assess the long-
term performance and reliability of RV systems, as well as the effects 
of harsh weather conditions on their long-term operation.

C. Sensor-Based Rear Object Detection Systems

Description
    Sensor-based object detection systems use electronic sensors that 
transmit a signal which, if an obstacle is present in a sensor's 
detection field, bounces the signal back to the sensor producing a 
positive ``detection'' of the obstacle. These sensors detect objects in 
the vicinity of a vehicle at varying ranges depending on the 
technology. To date, commercially-available object detection systems 
have been based on short-range ultrasonic technology or longer range 
radar technology, although advanced infrared sensors are under 
development as well.
    Sensor-based object detection systems have been available for over 
15 years as aftermarket products and for a lesser period as original 
equipment. Original equipment systems have been marketed as a 
convenience feature or ``parking aid'' for which the vehicle owner's 
manual can contain language denoting

[[Page 9491]]

sensor performance limitations with respect to detecting children or 
small moving objects. Aftermarket systems, however, are frequently 
marketed as safety devices for warning drivers of the presence of small 
children behind the vehicle.
    NHTSA has investigated the cost of sensor-based rear object 
detection systems. Currently, we estimate the cost of a backing system 
based on ultrasonic technology to be $51-$89 and the cost of a system 
based on radar technology to be approximately $92.\33\
---------------------------------------------------------------------------

    \33\ PRIA, section VI.
---------------------------------------------------------------------------

Research
NHTSA Research in Support of SAFETEA-LU
    NHTSA examined eight sensor-based original equipment and 
aftermarket rear parking systems in response to Section 10304 of the 
SAFETEA-LU mandate.\34\ NHTSA conducted testing to measure the object 
detection performance of short range sensor-based systems. Measurements 
included static field of view (i.e., both the vehicle and test objects 
were static), static field of view repeatability, and dynamic detection 
range for different laterally moving test objects. The agency assessed 
the system's ability to detect a 74-inch-tall adult male walking in 
various directions to the rear of the vehicle. Detection performance 
was also evaluated in a series of static and dynamic tests with 1-year-
old and 3-year-old children.
---------------------------------------------------------------------------

    \34\ 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.
---------------------------------------------------------------------------

    Sensor-based systems tested were generally inconsistent and 
unreliable in detecting pedestrians, particularly children, located 
behind the vehicle. Testing showed that, in most cases, pedestrian size 
affected detection performance, as adults elicited better detection 
response than 1 or 3-year-old children. Specifically, each system could 
generally detect a moving adult pedestrian (or other objects) behind a 
stationary vehicle; however, each system exhibited some difficulty in 
detecting moving children. The sensor-based systems tested were found 
to operate reliably (i.e., without malfunction), with the exception of 
one aftermarket ultrasonic system that malfunctioned after only a few 
weeks, rendering it unavailable for use in remaining tests.
    While examining the consistency of system detection performance, 
the agency observed that each sensor-based system exhibited some degree 
of variability in its detection performance and patterns. Specifically, 
detection inconsistencies were generally noticed at the periphery of 
the detection zones and typically for no more than 1 foot in magnitude. 
On average, these sensor-based systems had detection zones which 
generally covered an area directly behind the vehicle. The system with 
the longest detection range could detect a 3-year-old child up to 11 
feet from the rear bumper (along a 3-5 ft wide strip of area along the 
vehicle's centerline). The majority of systems were unable to detect 
test objects less than 28 inches in height.
    The response times of sensor-based systems were also evaluated in 
this study. In order for sensor-based backover avoidance systems to 
assist in preventing collisions, warnings must be generated by the 
system in a timely manner and the driver must perceive the warning 
within sufficient time to respond appropriately to avoid a crash. With 
regards to system response times, ISO 17386:2004,\35\ ``Manoeuvring 
Aids for Low Speed Operation (MALSO)--Performance requirements and test 
procedures'', outlines performance requirements for sensor-based object 
detection systems. This standard recommends a maximum system response 
time of 0.35 seconds. NHTSA's tests showed that the response times for 
the eight tested sensor systems varied from 0.18 to 1 second, and only 
three of them met the ISO response time limit. For the systems that did 
not meet the recommended 0.35-second limit, it is unlikely (assuming 
typical backing speeds \36\ and driver reaction times) that warnings 
would be provided to a driver in sufficient time to allow the driver to 
bring the vehicle to a stop and avoid a possible collision with an 
obstacle or moving child.
---------------------------------------------------------------------------

    \35\ ISO 17386:2004 Transport information and control systems--
Manoeuvring Aids for Low Speed Operation (MALSO)--Performance 
requirements and test procedures.
    \36\ Note that average backing speed was found to be 2.26 mph in 
NHTSA's ``On-Road Study of Drivers' Use of Rearview Video Systems 
(ORSDURVS).'' Mazzae, E.N., Barickman, F.S., Baldwin, G.H.S., and 
Ranney, T.A. (2008). National Highway Traffic Safety Administration, 
DOT 811 024, page 34.
---------------------------------------------------------------------------

NHTSA Experimental Research: Performance of Sensor-Based Rear Object 
Detection Systems
    NHTSA's 2008 study of drivers' use of rearview video systems \37\ 
involved an observation of drivers of vehicles equipped with an 
ultrasonic-based rear parking sensor system in addition to an RV 
system. In a staged experimental trial in which an unexpected obstacle 
was presented to test participants while backing out of a garage, the 
rear parking sensor system on the particular vehicle involved in this 
study detected the obstacle and provided a warning indication of the 
presence of the obstacle behind the vehicle in 38 percent (5 out of 13) 
of the event trials for participants with vehicles equipped with the 
combination system. These data describing the performance of a sensor-
based rear parking aid as used by average drivers reflect similar 
detection performance deficiencies as have been observed in NHTSA's 
laboratory testing of the detection performance of sensor-based object 
detection systems.38 39
---------------------------------------------------------------------------

    \37\ 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.
    \38\ 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.
    \39\ Mazzae, E.N. and Garrott, W.R., Experimental Evaluation of 
the Performance of Available Backover Prevention Technologies for 
Medium Straight Trucks, NHTSA Technical Report No. DOT HS 810 865, 
November 2007.
---------------------------------------------------------------------------

Paine, Macbeth & Henderson Proximity Sensor Research
    Paine, Macbeth & Henderson tested the performance of proximity 
sensor backing aids.\40\ They reported that proximity sensors tested 
exhibited limited ability to detect objects for vehicles traveling at 5 
km/h (3.1 mph) or more. According to their conclusions, proximity 
sensors were prone to produce ``nuisance alarms'' in some driving 
situations and were deemed an unviable option to reduce backing 
incidents. While the authors suggested that a more effective system to 
mitigate backing incidents may be to incorporate sensors and wide-angle 
video camera technology, no data were provided to support this 
statement.
---------------------------------------------------------------------------

    \40\ Paine, M., Macbeth, A., and Henderson, M. (2003). The 
Danger to Young Pedestrians from Reversing Motor Vehicles. 18th 
International Technical Conference on the Enhanced Safety of 
Vehicles. Paper Number 466.
---------------------------------------------------------------------------

GM Experimental Research on Sensor-Based Systems for the Reduction of 
Backing Incidents
    GM outlined the functional capabilities of their ultrasonic rear 
park assist system. The system was designed to detect larger poles and 
parking barriers greater than 7.5 cm in diameter with a length of 1.0 
meter or more. It was not designed to detect objects less than 25 cm in 
height. In addition, the system was not designed to detect obstacles 
directly below the bumper or under the vehicle. GM notes that smaller 
or thinner objects or pedestrians

[[Page 9492]]

may not be detected by this system, and indicates this fact explicitly 
in the system's instructional materials.41 42
---------------------------------------------------------------------------

    \41\ Instructional materials include the following warning: ``If 
children, someone on a bicycle, or pets are behind your vehicle, 
(ultrasonic rear park assist) won't tell you they are there. You 
could strike them and they could be injured or killed.''
    \42\ Green, C. and Deering, R. (2006). Driver Performance 
Research Regarding Systems for Use While Backing. Society of 
Automotive Engineers, Paper No. 2006-01-1982.
---------------------------------------------------------------------------

Observations
    The development of sensor-based systems for use as parking aids has 
been in progress for at least 15 years. Ultrasonic sensors inherently 
have detection performance that varies as a function of the degree of 
sonic reflectivity of the obstacle surface. For example, objects with a 
smooth surface such as plastic or metal reflect well, whereas objects 
with a textured surface, such as clothing, may not reflect as well. 
Radar sensors, which are able to detect the water in a human's body, 
are better able to detect pedestrians, but demonstrate inconsistent 
detection performance, especially with regard to small children.
    NHTSA is aware that the performance of current sensor-based systems 
can be influenced by the algorithms that are used for detection. As 
stated previously, these systems are implemented as parking aids rather 
than safety systems and thus this may have attributed to the observed 
performance. While it is possible to modify the detection algorithms of 
sensor-based object detection systems to allow for better detection of 
children, one result of such a modification could result in other less 
favorable aspects of system performance, such as increased false 
alarms. From a driver confidence standpoint, an increase in false 
alarms could have the effect of decreasing the system's overall 
effectiveness as a driver's desire to use the system decreases.

D. Multi-Technology (Sensor + Video Camera) Systems

Description
    In the context of this document, multi-technology backing aid 
systems are those systems that utilize both video and sensor-based 
technologies. Prior to MY 2007, these technologies functioned 
independently if both were present on a vehicle. Recently, truly 
integrated systems that use data from rear object detection sensors to 
present obstacle warnings that are superimposed on the RV display image 
have become commercially available. Whether integrated or not, vehicles 
equipped with both rearview video and sensor technologies have the 
ability to detect obstacles (via a rear parking sensor system) and 
alert a driver (by directing their attention to the rearview video 
system display) to the presence of the obstacle.
Research
    As previously mentioned in Part C of this section, NHTSA's work in 
response to Section 10304 of the SAFETEA-LU mandate included the 
measurement of the object detection performance of short range sensor-
based systems. One of the systems examined was the integrated rearview 
video and ultrasonic-based rear parking aid system of a 2007 Cadillac 
Escalade. This system used object detection information from an 
ultrasonic rear parking aid to present obstacle warnings to the driver 
through warning symbology superimposed on the RV display image. 
Specifically, a warning triangle symbol was shown on the RV display 
image in the approximate location of the obstacle. While the 
performance of the ultrasonic-based rear parking aid system showed the 
same issues as other tested systems using that sensor technology, the 
presentation of integrated warnings may be useful in directing a 
driver's attention to the image of a rear obstacle presented on the 
rearview video display. However, in order to assess the effectiveness 
of this or any other integrated system in mitigating backover 
incidents, research with drivers using the system is needed.
Observations
    Testing of the vehicle examined showed that the integrated rear 
parking aid and rearview video aspects of the backing aid system 
performed, from a sensor point of view, the same as would these two 
technologies if tested separately. The performance of the backing aid 
technologies present on this vehicle may not represent the performance 
of all such systems commercially available today. With improved 
technology integration that may utilize image processing to confirm the 
presence of rear obstacles, performance enhancements may be possible. 
The agency seeks comment on whether any recent studies have been 
performed with other integrated multi-technology backing aid systems.

E. Future Technologies

Description
    NHTSA is aware of two additional sensor technologies being 
developed that could be used to improve a vehicle's rear visibility; 
infrared-based object detection systems and video-based object 
recognition systems. As with other sensor systems, infrared-based 
systems emit a signal, which if an object is within its detection 
range, will bounce back and be detected by a receiver. Rear object 
detection via video camera uses real-time image processing capability 
to identify obstacles behind the vehicle and alert the driver of their 
presence.
Research
Ongoing NHTSA Backing Crash Countermeasure Research
    In addition to the previously mentioned rear-mounted convex mirror 
research, NHTSA is currently engaged in cooperative research with GM on 
Advanced Collision Avoidance Technology relating to backing incidents. 
The ACAT backing systems project is assessing the ability of more 
advanced technologies to mitigate backing crashes, and refining a tool 
to assess the potential safety benefit of these technologies. The focus 
of the ACAT Backing Crash Countermeasure Program is to characterize 
backing crashes in the U.S. and investigate a set of integrated 
countermeasures to mitigate them at appropriate points along the crash 
timeline (prior to entering the vehicle and continuing throughout the 
backing sequence). The objective of this research is to estimate 
potential safety benefits or harm reduction that these countermeasures 
might provide. A Safety Impact Methodology (SIM), consisting of a 
software-based simulation model together with a set of objective tests 
for evaluating backing crash countermeasures, will be developed to 
estimate the harm reduction potential of specific countermeasures. 
Included in the SIM's methods for estimating potential safety benefits 
will be a consideration of assessing and modeling unintentional 
potential disbenefits that might arise from a countermeasure.
Observations
    While these technology applications may eventually prove viable, 
because of their early stages of development it is not possible at this 
time to assess their ability to effectively expand the visible area 
behind a vehicle. Similarly, the completion of NHTSA's advanced 
technology research effort is not expected until calendar year 2011 and 
thus will not occur prior to the Congressional deadline. The agency 
seeks comments on the timeframe for the commercial availability of 
these technologies, and on any other

[[Page 9493]]

advanced technology developments not identified here.

F. Summary and Questions Regarding Technologies for Improving Rear 
Visibility

    Given the mandate from Congress to improve the rear visibility of 
vehicles, NHTSA's preliminary assessment of the known research to date 
seems to indicate that RV systems have greater potential to improve 
vehicles' rear visibility than sensor-based rear object detection 
systems and rear-mounted convex mirrors. However, we believe it is 
premature to limit manufacturers' design options at this time. To this 
end, we put forth the following questions and solicit comments on our 
assessments of these technologies, and any information on the 
feasibility of alternative approaches or systems.
    (1) While the objective to ``expand the required field of view to 
enable the driver of a motor vehicle to detect areas behind'' the 
vehicle implies enhancement of what a driver can visually see behind a 
vehicle, the language of the K.T. Safety Act also mentions that the 
``standard may be met by the provision of additional mirrors, sensors, 
cameras, or other technology.'' NHTSA seeks comment regarding the 
ability of object detection sensor technology to improve visibility and 
comply with the requirements of the Act.
    (2) What specific customer feedback have OEMs received regarding 
vehicles equipped with rear parking sensor systems? Have any component 
reliability or maintenance issues arisen? Is sensor performance 
affected by any aspect of ambient weather conditions?
    (3) What specific customer feedback have OEMs received regarding 
vehicles equipped with rearview video systems? Have any rearview video 
system component reliability or maintenance issues arisen?
    (4) What are the performance and usability characteristics of 
rearview video systems and rear-mounted convex mirrors in low light 
(e.g., nighttime) conditions?
    (5) Is there data available regarding consumers' and vehicle 
manufacturers' research regarding backing speed limitation, haptic 
feedback to the driver, or use of automatic braking?
    (6) What types of rear visibility countermeasures are anticipated 
to be implemented in the vehicle fleet through the 2012 timeframe?
    (7) Can rear-mounted convex mirrors be installed on light vehicles 
other than SUVs and vans? What is the rationale for U.S. manufacturers' 
choosing to install rear parking sensors and video cameras, rather than 
rear-mounted convex mirrors as are commonly installed on SUVs and 
minivans in Korea and Japan? NHTSA is particularly interested in any 
information on the effectiveness of rear-mounted convex mirrors in 
Korea and Japan.
    (8) NHTSA seeks any available research data documenting the 
effectiveness of rear convex cross-view mirrors in specifically 
addressing backover crashes.
    (9) NHTSA seeks comment and data on whether it is possible to 
provide an expanded field of view behind the vehicle using only rear-
mounted convex mirrors.
    (10) NHTSA is aware of research conducted by GM that suggests that 
drivers respond more appropriately to visual image-based confirmation 
of object presence than to non-visual image based visual or auditory 
warnings. Is there additional research on this topic?
    (11) NHTSA requests input and data on whether the provision of 
graphical image-based displays (e.g., such as a simplified animation 
depicting rear obstacles), rather than true-color, photographic visual 
displays would elicit a similarly favorable crash avoidance response 
from the driver.
    (12) To date, rearview video systems examined by NHTSA have 
displayed to the driver a rear-looking perspective of the area behind 
the vehicle. Recently introduced systems which provide the driver with 
a near 360-degree view of the area around the entire vehicle do so 
using a ``birds-eye'' perspective using images from four cameras around 
the vehicle. During backing, it appears that, by default, this birds-
eye view image is presented simultaneously along with the traditional 
rear-facing camera image. NHTSA requests data or input on whether this 
presentation method is likely to elicit a response from the driver that 
is at least as favorable as that attained using traditional, rear-view 
image perspective, or whether this presentation is more confusing for 
drivers.

VI. Drivers' Use and the Associated Effectiveness of Available 
Technologies To Mitigate Backovers

    In order to establish effectiveness estimates for different systems 
which may be utilized to mitigate backover crashes, the agency has 
conducted research on vehicles equipped with such systems, including 
those utilizing ultrasonic and radar sensors and rearview video 
cameras. As with any passive technology, NHTSA believes that it is 
reasonable to assume that in order for the technology to assist in 
preventing backing crashes, the driver must use the technology (e.g., 
look at the video display, if present), perceive the indication that a 
pedestrian or object is present, and respond quickly, and with 
sufficient force applied to the brake pedal, to bring the vehicle to a 
stop. While we have previously discussed the performance of the 
technologies, this section will outline what the agency knows about 
driver use and the resulting effectiveness of technologies that could 
be used to mitigate backover crashes.
    NHTSA has not conducted system effectiveness research with drivers 
for all of the four system types discussed in this notice. However, 
that relevant research NHTSA and industry have conducted is summarized 
here.

A. Rear-Mounted Convex Mirrors

    NHTSA has not conducted research focused on examining driver's use 
of mirrors to aid in the performance of backing maneuvers. However, 
NHTSA's study of drivers' use of rearview video systems during staged 
and naturalistic backing maneuvers did produce data regarding drivers' 
use of the side and interior rearview mirrors as well as direct glance 
behavior.\43\ This behavior suggests that drivers would use the 
mirrors. Table 7 shows that the mean percentage of total glance time 
during a backing maneuver in which drivers glanced at the driver-side 
mirror, passenger-side mirror, and interior rearview mirror. 
Independent of the presence of a backing aid, drivers spent over 25 
percent of the time during a backing maneuver glancing rearward over 
their right shoulder.
---------------------------------------------------------------------------

    \43\ 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.

[[Page 9494]]

 Table 7--Mean Percentage of Total Glance Time to Mirror Locations for a
       Backing Maneuver With Staged Obstacle Avoidance Event \44\
------------------------------------------------------------------------
                                                                 Mean
                                                              percentage
                                                               of total
                      Glance location                        glance time
                                                               during a
                                                               backing
                                                               maneuver
------------------------------------------------------------------------
Driver-side Mirror/Driver-side Window \45\.................           15
Interior Rearview Mirror...................................            5
Passenger-side Mirror/Passenger-side Window \46\...........           15
------------------------------------------------------------------------

    NHTSA is currently engaged in research to examine the performance 
of these mirrors in displaying images of rear obstacles. While NHTSA 
has not yet conducted driving research with these mirrors we are 
planning to conduct research to examine drivers' behavior and ability 
to avoid crashes with rear-mounted convex mirrors in 2009. Upon 
completion, this mirror research will be summarized in a published 
NHTSA report. Along with comments received to this notice, NHTSA hopes 
to use this research information in the development of a proposal.
---------------------------------------------------------------------------

    \44\ Id.
    \45\ Note that due to the close proximity of the mirror and 
window on each side of the vehicle, the driver-side mirror and 
driver-side window glance locations were impossible to distinguish 
from each other.
    \46\ Note that due to the close proximity of the mirror and 
window on each side of the vehicle, the passenger-side mirror and 
passenger-side window glance locations were impossible to 
distinguish from each other.
---------------------------------------------------------------------------

B. Rearview Video Systems

    NHTSA has conducted and we are aware of some work conducted by GM 
that examined drivers' use of rearview video based backing aids and 
their ability to use them to mitigate crashes. Below is a brief summary 
of this research.
NHTSA Experimental Research: On-Road Study of Drivers' Use of Rearview 
Video Systems
    NHTSA conducted experimental research aimed to determine whether 
drivers look at the RV display during backing. While hardware 
performance testing has shown the rearview video systems can provide to 
the driver an image of any obstacles behind the vehicle in the RV 
system's field of view, the driver must take the initiative to look at 
the display throughout the backing maneuver in order for the RV system 
to provide any benefit. The goal of this study was to further our 
understanding of the degree to which drivers may actively use RV 
systems while backing and whether the provision of such visual 
information will translate into decreased backing and backover 
incidents.
    This study also provided information useful in estimating the 
effectiveness of RV and supplemental sensors, in aiding drivers to 
avoid a backing crash. For example, the number of times per backing 
maneuver that a driver looked at the RV screen was tabulated. A driver 
that looks at the screen more often is more likely to notice when an 
obstacle appears. A look at the beginning of a backing maneuver is less 
likely to result in a driver's detection of an obstacle than would 
frequent checking of the screen throughout the maneuver.
    Drivers' use of rearview video systems was observed during staged 
and naturalistic backing maneuvers to determine whether drivers look at 
the RV display during backing and whether use of the system affects 
backing behavior.\47\ Thirty-seven test participants, aged 25 to 60 
years, were comprised of twelve drivers of RV-equipped vehicles, 
thirteen drivers of vehicles equipped with an RV system and a rear 
parking sensor system, and twelve drivers of vehicles with no backing 
aid system. All three system conditions were presented using original 
equipment configurations of the 2007 Honda Odyssey minivan. All 
participants had driven and owned a 2007 Honda Odyssey minivan as their 
primary vehicle for at least six months. Participants were not aware 
that the focus of the study was on their behavior and performance 
during backing maneuvers.
---------------------------------------------------------------------------

    \47\ 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.
---------------------------------------------------------------------------

    Participants drove their own vehicles for a period of four weeks in 
their normal daily activities while backing maneuvers were recorded. At 
the end of four weeks, participants returned to the research lab to 
have the recording equipment removed. At the lab, the participants took 
a test drive in which an unexpected 36-inch-tall obstacle consisting of 
a two-dimensional photograph of a child appeared behind the vehicle 
during a final backing maneuver. Additional details of the test method 
are provided in Appendix B of this notice.
    The results of the naturalistic driving and unexpected obstacle 
scenario are provided below.
Results for Naturalistic Driving
     A total of 6,145 naturalistic backing maneuvers were 
recorded in the study, none of which resulted in a significant 
collision; however, some collisions (i.e., with trash receptacles and 
other parked vehicles) occurred during routine backing.
     In the real-world backing situations, drivers equipped 
with RV systems spent 8 to 12 percent of the time looking at the RV 
display during backing maneuvers.
     On average, drivers made 2.17 glances per backing maneuver 
with the RV-only system, and 1.65 glances per maneuver with the RV and 
sensor system.
     Overall, drivers looked at least once at the RV display on 
approximately 65 percent of backing events, and looked more than once 
at the RV display on approximately 40 percent of backing events.
Results for Unexpected Obstacle Maneuver
     Drivers with an RV system made 13 to 14 percent of glances 
at the RV video display during the initial phase of backing in the 
staged maneuvers, independent of system presence.
     Drivers spent over 25 percent of backing time looking over 
their right shoulder in the staged backing maneuvers.
     Only participants who looked at the RV display more than 
once during the maneuver avoided a crash during the staged crash-
imminent obstacle event.
     Results indicated that the RV system was associated with a 
statistically significant (28 percent) reduction in crashes with the 
unexpected obstacle as compared to participants without an RV system. 
All participants in the ``no system'' condition crashed, since the 
staged obstacle event scenario was designed such that drivers without 
an RV system could not see the obstacle.
    Results of this study indicate that drivers looked at the RV 
display in approximately 14 percent of glances in baseline and obstacle 
events and 10 percent of glances in naturalistic backing maneuvers. The 
agency recognized that the timing and frequency of drivers' glances at 
the RV display has a noticeable impact on the likelihood of rear 
obstacle detection. However, making single or multiple glances at the 
RV display at the start of the maneuver does not ensure that the path 
behind the vehicle will remain clear for the entire backing maneuver.
    Overall, this study estimates that video-based backing systems 
would

[[Page 9495]]

mitigate approximately 28 to 42 percent of backover crashes \48\.
---------------------------------------------------------------------------

    \48\ 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.
---------------------------------------------------------------------------

GM Experimental Research on Driver Performance Using Video-Based 
Backing Aid Systems
    GM conducted research to investigate ways to assist drivers in 
recognizing people or objects behind their vehicle while performing 
backing maneuvers.\49\ One study compared parking behaviors for rear 
camera and ultrasonic rear parking assist systems together, separately, 
and under traditional parking conditions (i.e., neither system). An 
obstacle was placed unexpectedly behind a driver's vehicle prior to the 
start of a backing maneuver to assess the driver's performance in 
obstacle detection and avoidance.\50\ Twenty-four participants struck 
the obstacle, while five participants avoided the obstacle. Of those 
participants who avoided the obstacle, three saw the obstacle while 
looking at the RV display (two in the RV system condition, one in the 
ultrasonic rear park assist and RV system condition), one saw the 
obstacle in their mirror (ultrasonic rear park assist and RV system 
condition), and one participant noticed the obstacle out of the back 
window (RV system condition). These results indicated that participants 
with an RV system were less likely to be involved in a backing 
incident.
---------------------------------------------------------------------------

    \49\ Green, C. and Deering, R. (2006). Driver Performance 
Research Regarding Systems for Use While Backing. Society of 
Automotive Engineers, Paper No. 2006-01-1982.
    \50\ McLaughlin, S.B., Hankey, J.M., Green, C.A., and Kiefer, 
R.J. (2003). Driver Performance Evaluation of Two Rear Parking Aids. 
Proceedings of the 2003 Enhanced Safety Vehicle Conference.
---------------------------------------------------------------------------

    GM also sponsored a second research study to evaluate driver 
performance with rear camera systems.\51\ In this study, each 
participant parked their vehicle using a rear camera and ultrasonic 
system more than 30 times, including practice trials. During one 
scenario, participants, unaware that an experimenter placed an obstacle 
behind the vehicle, were asked to perform a backing maneuver to engage 
the ultrasonic rear park assist and the rear camera system. In some 
cases, a flashing symbol was employed in the approximate location of 
the rear obstacle as presented on the video display screen. While there 
were no statistically significant effects of either the symbol or the 
location of the obstacle, 65 percent of participants avoided the 
obstacle. Greater experience with the camera system and an increased 
number of trials presented that involved a ruse may have attributed to 
a higher object avoidance rate in this study than compared to the first 
study.
---------------------------------------------------------------------------

    \51\ Green, C. and Deering, R. (2006). Driver Performance 
Research Regarding Systems for Use While Backing. Society of 
Automotive Engineers, Paper No. 2006-01-1982.
---------------------------------------------------------------------------

    Overall, GM's research on rearview video systems suggested that RV 
systems may provide limited benefit in some backing scenarios.\52\
---------------------------------------------------------------------------

    \52\ Green, C. and Deering, R. (2006). Driver Performance 
Research Regarding Systems for Use While Backing. Society of 
Automotive Engineers, Paper No. 2006-01-1982.
---------------------------------------------------------------------------

C. Sensor-Based Rear Object Detection Systems

    NHTSA and GM have both conducted research on drivers' use of 
sensor-based backing aids and their ability to use them to mitigate 
crashes. Below is a brief summary of this research.
NHTSA Experimental Research: Driver Performance With Rearview Video and 
Sensor-Based Rear Object Detection Systems
    NHTSA's study of drivers' use of rearview video systems (discussed 
in detail earlier in this document) also involved an observation of 
drivers of vehicles equipped with both an RV system and an ultrasonic-
based rear parking sensor system. The rear parking sensor system tested 
detected the obstacle and provided a warning indication of the presence 
of a rear obstacle to the driver in 38 percent (5 out of 13) of the 
event trials for participants with vehicles equipped with the 
combination system. Four of these 5 participants crashed into the 
obstacle.
    The test vehicle involved in the study had a control that allowed 
the driver to disable the parking sensor system. During the course of 
this study, half of the participants whose vehicles were equipped with 
a rear parking sensor system either stated or were observed to have 
turned the system off at least some of the time. Four participants made 
unsolicited comments to members of the research staff about turning off 
the rear parking sensor system on their vehicle.\53\ One of the four 
participants reported that he just did not use it. The three other 
participants stated that they frequently turned the rear parking sensor 
system off when driving through a restaurant drive-through lane due to 
nuisance alarms (i.e., audible notifications of the presence of 
vehicles that the driver is already aware of). A sixth participant did 
not comment on not using the system, but was observed having the rear 
parking sensor system on their vehicle switched off during their 
initial meeting visit. This tendency for some drivers to turn the rear 
parking sensor system off causes NHTSA to be concerned about the 
potential for this technology to be effective in mitigating backover 
incidents.
---------------------------------------------------------------------------

    \53\ 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.
---------------------------------------------------------------------------

GM Experimental Research on Driver Performance Using Sensor-Based 
Backing Aid Systems
    GM sponsored a study on the effectiveness of auditory backing 
warnings provided by a rear object detection system.\54\ The study 
found that only 13 percent of drivers avoided hitting an unexpected 
obstacle, and over 87 percent of the drivers collided with the obstacle 
following the warning. Sixty-eight percent of drivers provided with the 
warning demonstrated precautionary behaviors in response to the 
warning, such as covering the brake with their foot, tapping the brake, 
or braking completely. While 44 percent of participants braked, these 
braking levels were generally insufficient to avoid a collision. 
Although data provides some evidence that warnings influenced driver 
behavior, warnings were unreliable in terms of their ability to induce 
drivers to immediately brake to a complete stop.
---------------------------------------------------------------------------

    \54\ Green, C. and Deering, R. (2006). Driver Performance 
Research Regarding Systems for Use While Backing. Society of 
Automotive Engineers, Paper No. 2006-01-1982.
---------------------------------------------------------------------------

    This study further suggests that knowledge and experience with a 
backing warning system may not significantly improve immediate driver 
response to a backing warning. While specific training on the operation 
of the system was provided to eight drivers, only one avoided the 
obstacle. In each case, drivers reported that they did not expect to 
encounter an obstacle in their backing path. Many drivers also reported 
that they searched for an obstacle following the warning, but ``didn't 
see anything'' and continued their backing maneuver. These perceptions 
suggest that drivers' expectations are important when seeking to 
influence driver behavior.
NHTSA Experimental Research: Driver Performance With Sensor-Based Rear 
Object Detection Systems
    NHTSA is currently engaged in research to assess drivers' ability 
to avoid backing crashes in a vehicle equipped with only a sensor-based 
rear object detection system. This work is scheduled to be completed in 
2009 and

[[Page 9496]]

will be summarized in a published NHTSA report thereafter. Along with 
comments received to this notice, NHTSA hopes to use this research 
information in the development of a proposal.

D. Multi-Technology (Sensor + Camera) Systems

    NHTSA has not conducted research examining drivers' use of any 
integrated, multi-technology systems designed to aid drivers in 
performing backing maneuvers. However, NHTSA's study of drivers' use of 
rearview video systems (discussed in detail earlier in this document) 
involved an observation of drivers of vehicles equipped with both an RV 
system and an ultrasonic-based rear parking sensor system that 
functioned independently. Data from this study indicated that equipping 
a vehicle with a rear object detection system and an RV system that are 
not integrated resulted in lesser backing crash avoidance effectiveness 
than attainable with RV alone. Although statistically not significant 
due to the relatively small number of test participants, more 
participants with vehicles equipped with both an RV and a rear parking 
sensor system (85 percent) crashed into an obstacle than did those (58 
percent) driving vehicles equipped with only an RV system. However, the 
fact that the rear parking sensor system only detected the obstacle in 
38 percent of test trials may help explain the result if the drivers 
relied on the sensor system first. NHTSA's research on the performance 
of currently available sensor-based systems in detecting rear obstacles 
has shown their performance to be inconsistent, particularly in the 
detection of small children. It is possible that those performance 
deficits for sensor-based rear object detection systems could have a 
negative impact on the overall effectiveness of RV systems, 
particularly if drivers rely on the sensor system's auditory alerts to 
cue them to look at the RV display.
    During our study, drivers of the vehicles with RV and sensors 
looked at the RV system visual display less frequently than did drivers 
of the same vehicle equipped with only the RV system. NHTSA seeks 
comment on whether there is research that would indicate why this would 
occur or if others have found a similar trend.

E. Summary

    Table 8 presents a summary of the estimated effectiveness 
information for systems that may aid in the mitigation of backover 
incidents that NHTSA has collected to date. Estimates for system 
performance in detecting rear obstacles and overall effectiveness based 
on driver use are listed separately. System performance for rearview 
video systems was assumed to be 100 percent, since these systems have 
the capability to show any object within their field of view. System 
performance for sensor-based systems is based on object detection rates 
seen in the obstacle avoidance event presented in the study of drivers' 
use of rearview video systems.\55\ Overall effectiveness values for 
rearview video systems alone and combined with a rear parking sensor 
system are based on results of NHTSA's study of drivers' use of 
rearview video systems. The value for rear parking sensor systems is 
calculated based on a combination of the 39 percent object detection 
rate from the study of drivers' use of rearview video systems and 
additional data that NHTSA has collected. We note that GM's study of 
drivers' use of backing warning systems found that only 13 percent of 
drivers were able to avoid a crash with a rear obstacle in a staged 
scenario using a rear parking sensor system.\56\
---------------------------------------------------------------------------

    \55\ 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.
    \56\ General Motors (2006). Driver Performance Research 
Regarding Systems for Use While Backing. Society of Automotive 
Engineers, Paper No. 2006-01-1982.

     Table 8--Estimated System Performance and Overall Effectiveness
------------------------------------------------------------------------
                                  System performance    Percent overall
                                       in object         effectiveness
         Countermeasure               detection--        (technology +
                                  percent detections        driver)
------------------------------------------------------------------------
Rear-Mounted Convex Mirrors.....  (Research           (Research
                                   underway).          underway).
Rearview Video..................  100...............  42 \57\.
Rearview Video + Sensors........  100...............  15 \58\.
Sensors.........................  39 \59\...........  17.66 \60\
                                                       (estimate).
------------------------------------------------------------------------

F. Questions

    (1) NHTSA has not conducted research to estimate a drivers' ability 
to avoid crashes with a backing crash countermeasure system based only 
on sensor technology. We request any available data documenting the 
effectiveness of backing crash countermeasure systems based only on 
sensor technology in aiding drivers in mitigating backing crashes.
    (2) NHTSA has not conducted research to estimate drivers' ability 
to avoid crashes with a backing crash countermeasure system based on 
multiple, integrated technologies (e.g., rear parking sensors and 
rearview video functions in one integrated system). We request any 
available objective data documenting the effectiveness of multi-
technology backing crash countermeasure systems in mitigating backing 
crashes. We also request comment on what types of technology 
combinations industry may consider feasible for use in improving rear 
visibility.
---------------------------------------------------------------------------

    \57\ 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.
    \58\ Id.
    \59\ Id.
    \60\ PRIA, section V.
---------------------------------------------------------------------------

    (3) NHTSA requests any available data documenting the image quality 
of rear-mounted convex mirrors and their effectiveness in aiding 
drivers in preventing backing crashes.
    (4) NHTSA requests any available additional objective research data 
documenting the effectiveness of sensor-based, rearview video, mirror, 
or combination systems that may aid in mitigating backover incidents.
    (5) NHTSA requests information regarding mounting limitations for 
rear-mounted convex mirrors.

VII. Rear Visibility of Current Vehicles

    The degree of direct rear visibility (i.e., what a driver can 
directly see with or without the aid of non-required mirrors or other 
devices) in a particular vehicle depends on a number of factors, 
including the driver's size and various aspects of the vehicle's 
design, such as the width of a vehicle's structural pillars (i.e., B 
and C pillars) and the size of its window openings. Rear seat head 
restraints can also affect direct rear

[[Page 9497]]

visibility.\61\ Additionally, due to their geometries and the position 
of a driver's eyes with respect to the bottom of the rear window (or 
top edge of a pickup truck's tailgate), vehicles with greater overall 
height and length are likely to have larger rear blind zone areas than 
shorter vehicles.
---------------------------------------------------------------------------

    \61\ Note that 49 CFR Sec. 571.111 Standard No. 111, Rearview 
mirrors, Section 5.1.1 states that ``The line of sight may be 
partially obscured by seated occupants or by head restraints.''
---------------------------------------------------------------------------

    To assess a vehicle's rear visibility and how it varies from 
vehicle to vehicle, in 2007,\62\ NHTSA measured the rear visibility 
characteristics of 44 recent-model light vehicles.\63\ NHTSA's 
measurements involved assessment of the visibility of a visual target 
over an area stretching 35 feet to either side of the vehicle's 
centerline, 90 feet back from the vehicle's rear bumper, and 20 feet 
forward of the rear bumper. Rear visibility metrics were calculated 
using a subset of this area measuring 60 feet wide by 50 feet long 
(3000 square feet). The agency selected a 29.4-inch-tall visual target 
representing the approximate height of a 1-year-old child and the 
youngest walking potential backover victims. Rear visibility was 
measured for both a 50th percentile adult male driver (69.1 inches 
tall) and a 5th percentile adult female driver (59.8 inches tall). The 
areas over which the visual target was visually discernible using 
direct glances (i.e., looking out vehicle windows) and indirect glances 
(i.e., looking into side or interior rearview mirrors) were determined.
---------------------------------------------------------------------------

    \62\ Mazzae, E.N., Garrott, W.R. (2008). Light Vehicle Rear 
Visibility Assessment. National Highway Traffic Safety 
Administration, DOT 810 909.
    \63\ Measured vehicles included the ten top-selling passenger 
cars and light trucks for calendar year 2006.
---------------------------------------------------------------------------

    While NHTSA measured the area indirectly visible to the driver in 
the side and interior rearview mirrors, we focused our assessment on 
direct rear visibility in order to assess the degree to which the 
vehicle's structure affects what a driver can see out the vehicle's 
windows. This permitted an assessment of how rear visibility is 
affected by a vehicle's structure and allowed for better vehicle 
comparison since this metric varied more than would rear visibility 
measured using both direct vision and indirect vision devices together. 
In other words, considering both direct and indirect rear visibility 
together would allow less room for distinguishing between the qualities 
of rear visibility amongst vehicles. Examples of the measured direct 
fields of view for four common vehicles types are shown in Figures 5-8.
BILLING CODE 4910-59-P

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BILLING CODE 4910-59-C
    Through this study, NHTSA estimated that rear blind zone areas \64\ 
for individual vehicles ranged from approximately 100 to 1,440 square 
feet over the 3,000 square-foot measurement area. When summarized by 
vehicle category and curb weight (as a surrogate indicator for vehicle 
size), as illustrated in Figure 9, the data shows that average direct-
view rear blind zone areas varied within these groups. The greatest 
range of direct-view rear blind zone area size was seen for the 4,000-
5,000 lb SUV group. Figure 10 illustrates that SUVs (as a whole) were 
associated with the largest average direct-view rear blind zone area as 
well as the largest range of values for the four body types examined. 
Overall, LTVs (vans, pickups, and SUVs) as a vehicle class were 
observed to have larger rear blind zone areas than passenger cars, as 
indicated in Figure 10.
---------------------------------------------------------------------------

    \64\ ``Rear blind zone area'' is defined here to mean the area 
in square feet within a 50-foot wide by 60-foot long area and at 
ground level over which a 29.4-inch-tall object is visible using 
direct vision.

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

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[GRAPHIC] [TIFF OMITTED] TP04MR09.009

    For all 44 vehicles, NHTSA also measured the distance behind the 
vehicle at which the visual target could first be seen, i.e., the 
direct-view rear longitudinal sight distance. Average direct-view rear 
longitudinal sight distances were determined by mathematically 
averaging eight longitudinal sight distance measurements taken in 1-
foot increments across the rear of each vehicle. As illustrated in 
Figure 11, LTVs generally had longer rear longitudinal sight distances 
than passenger cars. Exceptions to this trend included a few small 
pickup trucks for which average direct-view rear sight distance values 
were in the vicinity of those measured for smaller passenger cars, as 
shown in Figure 12. Average direct-view rear sight distance values

[[Page 9503]]

were longest for a full-size van, SUVs and pickup trucks with a curb 
weight of 4,000 lbs or greater.
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[[Page 9504]]

    Overall, our direct-view rear visibility measurements indicated 
that LTVs measured in this study exhibited worse rear visibility when 
compared with passenger cars, but there was overlap amongst all vehicle 
categories.

VIII. Relationship Between Rear Visibility and Backing/Backover Crashes

    Using the direct-view rear blind zone area and longitudinal sight 
distance measurements \65\ discussed in the prior section, NHTSA 
investigated whether a statistical relationship could be identified 
between these metrics and all backing crashes, as well as backover 
crashes (i.e., the subset of backing crashes involving a pedestrian or 
bicyclist being struck by a backing vehicle).\66\ NHTSA assessed the 
relationship between real world backing/backover crashes and rear 
visibility based on three metrics: average rear longitudinal sight 
distance, direct-view rear visibility measurements for a 50 feet long 
by 60 feet wide \67\ test area, and direct-view rear visibility for a 
50 feet long by 20 feet wide \68\ test area.
---------------------------------------------------------------------------

    \65\ Mazzae, E.N., Garrott, W.R. (2008). Light Vehicle Rear 
Visibility Assessment. National Highway Traffic Safety 
Administration, DOT 810 909.
    \66\ Partyka, S., Direct-View Rear Visibility and Backing Risk 
for Light Passenger Vehicles (2008).
    \67\ This area was chosen because it was the largest available 
measurement area for the facility in which these measurements were 
conducted.
    \68\ The 50 feet long by 20 feet wide test area was examined to 
assess how much of the area behind the vehicle was critical to 
consider for rear visibility in relation to the prevention of 
backover incidents.
---------------------------------------------------------------------------

    Backing risk was estimated from police-reported crashes in the 
State Data System.\69\ To calculate risk, backing rates were derived 
for 21 vehicle groups with vehicles that had at least 25 backing 
crashes to account for statistical variability. Backing rate data were 
provided by the following states for the specified calendar years:
---------------------------------------------------------------------------

    \69\ The states provide annual files of their police-reported 
data under voluntary agreements with NHTSA. These are collected by 
the National Center for Statistics and Analysis, Office of Data 
Acquisition. The data are available for agency use. Public release 
of any of the files requires written approval from the individual 
state.

 Alabama (2000-2003)
 Florida (2000-2005)
 Georgia (2000-2005)
 Illinois (2000-2005)
 Kansas (2001-2006)
 Kentucky (2000-2005)
 Maryland (2000-2005)
 Michigan (2004-2006)
 Missouri (2000-2005)
 Nebraska (2000-2004)
 New Mexico (2001-2006)
 New York (2000)
 North Carolina (2000-2005)
 Pennsylvania (2000-2001, 2003-2005)
 Utah (2000-2004)
 Washington (2002-2005)
 Wisconsin (2000-2005)
 Wyoming (2000-2005)
    Simple correlation analysis \70\ revealed an association between 
direct-view rear blind zone area and backing crash risk. Specifically, 
larger blind zone areas tended to be associated with a greater risk of 
being involved in a backing crash. A statistically significant 
relationship \71\ between backing crash risk and direct-view rear blind 
zone area was discovered for both test areas, suggesting that this 
metric is a sensitive predictor of backing crash risk. However, in this 
analysis, the association between average rear longitudinal sight 
distance and backing risk was found to be weaker and not statistically 
significant due to the relatively small number of backover incidents, 
suggesting that this metric is not a sensitive predictor of backing 
crash risk.\72\
---------------------------------------------------------------------------

    \70\ A simple correlation measures the strength of the 
statistical relationship between two variables. For example, one can 
graph two variables (such as the real-world risk of being involved 
in a backing crash as a function of laboratory measures of rear 
visibility) as a scatter plot. A simple correlation analysis 
measures how closely the plot resembles a line. If the plot suggests 
a line, then we might conclude that the laboratory measures are 
useful in predicting real-world involvements. However, it is 
difficult to use this approach if one suspects that there are 
complicating (confounding) factors that affect the simple comparison 
between two variables.
    \71\ r=0.51, p=0.02.
    \72\ r=0.26.
---------------------------------------------------------------------------

    Logistic analysis \73\ for the risk of a backover incident produced 
results that approached statistical significance for the rear blind 
zone area metrics, with a similar trend and magnitude as those for all 
backing crashes. Vehicles with the largest blind zone areas had 2-3 
times the risk of a backover incident than those vehicles with the 
smallest blind zone areas.\74\ Conversely, estimated results for the 
risk of backover using rear longitudinal sight distance were not 
statistically significant.
---------------------------------------------------------------------------

    \73\ A logistic analysis allows us to account for complicating 
factors (such as systematic differences in how vehicles are used and 
by whom) by including them in a statistical model. This model 
predicts the risk of a crash being a backing crash as a function the 
laboratory measures of rear visibility after removing (controlling 
for) the effects of measurable complicating factors.
    \74\ Partyka, S., Direct-View Rear Visibility and Backing Risk 
for Light Passenger Vehicles (2008).
---------------------------------------------------------------------------

IX. Options for Mitigating Backover Incidents

    Using rear blind zone area as a metric, NHTSA's research seems to 
indicate that there is a range of performance amongst vehicles and that 
LTVs on average had worse rear visibility than passenger cars. NHTSA 
also found a statistically significant correlation between rear blind 
zone area and backing crashes. Finally, our crash data appear to 
indicate that LTVs are overrepresented in backing and backover crashes. 
Based on these findings, NHTSA has identified potential approaches to 
improve rear visibility and to address the backing and backover crash 
risks for passenger vehicles.

A. Approaches for Improving Vehicles' Rear Visibility

    One approach would be to eliminate all rear blind zones by 
requiring that all vehicles have a rear blind zone size of 0 sq. ft. 
(i.e., no rear blind zone). Such a requirement would be met by a 
visibility enhancement countermeasure that allowed the driver to see or 
otherwise determine that a pedestrian is in a specified zone behind the 
vehicle. This strategy would improve rear visibility for all vehicles.
    Alternatively, NHTSA could specify that all LTVs as a vehicle class 
have no rear blind zone since our crash data indicated that this 
vehicle category seems to be overrepresented in backing and backover 
crashes. This alternative would target the class of vehicles which are 
disproportionately responsible for the largest portion of backover 
fatalities.
    Another approach would be to establish a maximum rear blind zone 
area limit (based on crash rate) that all vehicles, or LTVs as a 
vehicle class, would have to meet.\75\ The threshold would be applied 
to all vehicles, such that any vehicle not meeting the minimum rear 
visibility threshold would be required to be equipped with a rear 
visibility countermeasure. Because styling engineers would have a 
target threshold giving them an idea of minimum ``acceptable'' rear 
visibility, such an approach would allow manufacturers the flexibility 
to consider and improve those attributes of a vehicle that contribute 
to rear visibility since they would have the option of not having to 
provide a rear visibility enhancement countermeasure. Depending on how 
high or low the threshold was set, for example, the agency could focus 
countermeasure application on vehicles with the largest rear blind zone 
areas and those vehicles

[[Page 9505]]

that are most involved in backing and backover crashes.
---------------------------------------------------------------------------

    \75\ Additional details on how a rear blind zone area based 
threshold might be developed are in Appendix D.
---------------------------------------------------------------------------

    Using these approaches, NHTSA offers our preliminary information 
regarding the benefits and costs of various scenarios.

B. Cost Benefit Scenarios

    For the relevant technologies, we have generated estimates using 
two different types of video cameras available in the market today and 
two different types of object detection sensors. For rearview video 
systems, some manufacturers are using cameras with a 130-degree field 
of view while others are using ones with a 180-degree field of view. 
These are noted as ``130 [deg] Camera'' and ``180 [deg] Camera,'' 
respectively. Note that these angular values are camera specifications 
and indicate the angle of view with respect to the center of the camera 
lens and not the center of the rear of the vehicle. Due to styling 
issues, cameras on some vehicle models may be mounted off-center and, 
as a result, their fields of view may not be symmetrical with respect 
to the center of the vehicle's rear bumper. The sensor technologies 
included in the estimates are ultrasonic and radar. It should be noted 
that given our lack of information regarding the effectiveness of 
mirrors, we could not generate a cost benefit scenario using this 
technology.
    Using various scenarios, NHTSA has developed preliminary estimates 
of the costs and benefits for improving rear visibility assuming 16.6 
million (8.5 million LTVs and 8.1 million passenger cars) total 
vehicles.\76\ One scenario involves the application of a rear 
visibility countermeasure to all vehicles and a second assumes that a 
countermeasure is applied to all LTVs and no passenger vehicles. Given 
that a rear visibility threshold has not yet been established and that 
NHTSA has not measured all vehicle models sold in the U.S. to determine 
their rear blind zone areas, two additional, hypothetical scenarios 
were considered. One scenario assumes that a rear visibility 
countermeasure would be required for all LTVs and any passenger cars 
that do not comply with the rear visibility threshold (hypothetically 
assumed to encompass 25 percent of vehicles).\77\ Another scenario 
assumes that a rear visibility countermeasure would be required for any 
light vehicle that does not comply with the rear visibility threshold 
(hypothetically assumed to encompass 75 percent of LTVs and 25 percent 
of passenger cars).\78\ Table 9 presents the overall range of costs and 
benefits across these four scenarios.
---------------------------------------------------------------------------

    \76\ This sales figure represents 2007 vehicle sales. For the 
subsequent NPRM, updated sales figures will be used.
    \77\ To illustrate this approach, this example scenario assumes 
that 25 percent of passenger cars will not comply with the rear 
visibility threshold.
    \78\ To illustrate this approach, this example scenario assumes 
that 75 percent of LTVs and 25 percent of passenger cars will not 
comply with the rear visibility threshold.

    Table 9--Preliminary Benefits and Costs Estimates--Across Four Countermeasure Application Scenarios \79\
----------------------------------------------------------------------------------------------------------------
                                       Net cost  (does
                                         not consider
  Countermeasure technology options    vehicles already    Cost per life     Total fatalities    Total injuries
                                      equipped with RV)    saved  (in $M)        avoided            avoided
                                           (in $M)
----------------------------------------------------------------------------------------------------------------
RV with 130 [deg] Camera and              $1,153-$2,577      $16.17-$57.27              26-69        1,279-5,189
 Interior Mirror Display............
RV with 130 [deg] Camera and In-Dash          981-2,294        15.69-56.41              26-69        1,279-5,189
 Display............................
RV with 180 [deg] Camera and                1,325-3,005        13.76-50.99              31-82        1,689-6,141
 Interior Mirror Display............
RV with 180 [deg] Camera and In-Dash        1,234-2,811        14.61-52.76              31-82        1,689-6,141
 Display............................
Ultrasonic Rear Object Detection                277-766        11.25-33.84               5-24          399-1,793
 System.............................
Radar Rear Object Detection System..          571-1,397        21.02-49.84               6-26          479-1,976
                                     ---------------------------------------------------------------------------
Rear-mounted Convex Mirrors.........                            (Research in progress)
----------------------------------------------------------------------------------------------------------------

    Additional details regarding these calculations can be found in the 
preliminary regulatory impact analysis document, ``Rear Visibility 
Technologies: FMVSS No. 111.'' NHTSA will continue to gather 
information on price and vehicle equipment trends for use in refining 
these estimates of costs and benefits for improving rear visibility.
---------------------------------------------------------------------------

    \79\ Cost calculations presented in Table 9 assume a 3 percent 
discount rate. Values also consider ranges of effectiveness for the 
technologies listed. Additional details regarding these calculations 
can be found in the PRIA.
---------------------------------------------------------------------------

C. Questions

    NHTSA requests comments on benefits and costs for rear visibility 
enhancement countermeasures and the possibility of developing a rear 
blind zone area based minimum acceptable rear visibility threshold. 
Specific questions are as follows:
    (1) NHTSA seeks comment on the areas behind a vehicle that may be 
most important to consider when improving rear visibility. Furthermore, 
while the distribution of visible area behind the vehicle was not 
considered in the blind zone area metrics (e.g., rear blind zone area) 
discussed in this document, it may be helpful to specify some specific 
areas behind the vehicle that must be visible.
    (2) NHTSA invites comment as to how an actual threshold based on 
vehicles' rear blind zone area could be defined.
    (3) For vehicles whose rear visibility does not meet a required 
minimum threshold and thus require a countermeasure, OEMs may decide to 
further alter the styling of the rear of the vehicle to the detriment 
of direct rear visibility (e.g., making the rear window a tiny, 
circular porthole). Based on the fact that NHTSA's research \80\ showed 
that drivers of RV-equipped vehicles glanced at least one time at the 
RV display in only 65 percent of backing maneuvers, maintaining good 
direct rear visibility may be important for the other 35 percent of 
cases in which the RV system is not used. Therefore, NHTSA is 
considering specifying a minimum portion of a vehicle's rear visibility 
that must be provided via direct vision (i.e., without the use of 
mirrors or other indirect vision device). NHTSA seeks comments on this 
approach, such as input regarding how a minimum threshold should be 
specified, and how much of a vehicle's rear area should be visible via 
direct vision?
---------------------------------------------------------------------------

    \80\ 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.

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

[[Page 9506]]

    (4) NHTSA requests information regarding anticipated costs for rear 
visibility enhancement countermeasures.
    (5) Given the increasing popularity of LCD panel televisions and 
likely resulting price decline, what decline in price can be 
anticipated for LCD displays used with rearview video systems? Will 
similar price reduction trends be seen for video cameras for rearview 
video system application?
    (6) NHTSA requests information on the estimated price of rear 
visibility enhancement countermeasures at higher sales volumes, as well 
as the basis for such estimates.
    (7) NHTSA requests any available data on rearview video system 
maintenance frequency rates and replacement costs. How often are 
rearview video cameras damaged in the field?
    (8) NHTSA requests comments on which types of possible rear 
visibility enhancement countermeasure technologies may be considered 
for use on which types of vehicles. This information is important for 
estimating the costs of countermeasure implementation in the fleet.
    (9) NHTSA requests information regarding available studies or data 
indicating the effectiveness of dashboard display-based rearview video 
systems and rearview mirror based rearview video systems. What are the 
key areas that will impact the real-world effectiveness of these 
systems as they become more common in the fleet?
    (10) NHTSA requests objective data on the use, effectiveness, and 
cost of rear-mounted convex mirrors.

X. Options for Measuring a Vehicle's Rear Visibility

    If a maximum rear blind zone area limit threshold is used to 
establish the need for a vehicle to be equipped with a countermeasure, 
its rear visibility characteristics would need to be measured and that 
vehicle's direct-view rear visibility and rear blind zone areas would 
need to be calculated. As such, if the agency chooses to establish a 
threshold value for minimum performance, a test procedure would need to 
be developed. In this section, the agency identifies those test 
procedures it has identified that could be used for this purpose. The 
advantages and disadvantages of the different identified methods are 
also discussed.

A. Rear Visibility Measurement Procedures

Society of Automotive Engineers
    The Society of Automotive Engineers (SAE) \81\ has created a 
recommended practice for determining the areas around a vehicle that a 
driver can see through direct vision (i.e., without the use of mirrors 
or another indirect vision device). This procedure uses computer-based 
simulations to describe rear visibility for a particular vehicle. Using 
standard driver eye points and a three-dimensional computer model of 
the vehicle, the simulation allows the rotation of sight lines 
originating from the eye points to determine the areas that the driver 
should be able to see outside the vehicle.\82\ This approach to 
determine a vehicle's visibility characteristics is theoretical and has 
not been assessed for reproducibility and repeatability against actual 
vehicles.
---------------------------------------------------------------------------

    \81\ SAE J1050, Describing and Measuring the Driver's Field of 
View; Revised 2003-01.
    \82\ Note: NHTSA has not evaluated the engineering drawings or 
three-dimensional computer models of manufactured vehicles, on which 
this method appears to rely.
---------------------------------------------------------------------------

Paine, Macbeth & Henderson
    In 2003, Paine, Macbeth & Henderson described a method to 
approximate a driver's sight line using an H-point machine and laser 
pointing device. Using the data, a ``visibility index'' was calculated 
to highlight the researchers' belief that vehicle design plays a major 
role in the rear visibility of vehicles.
    This study, sponsored by the Insurance Australia Group, was 
designed to be easily repeatable and standardized to enable accurate 
comparisons between vehicles.\83\ The laser device was mounted to the 
side of the H-point machine's head fixture in the approximate vicinity 
of where a driver's head would be located. A dimensioned grid was 
positioned behind the test vehicle and a test target consisting of a 
cylinder 600 mm (24 in.) tall and 200 mm (7.87 in.) in diameter was 
used. Additionally, the driver's seat was placed in its lowest and 
furthest back position and adjusted to ensure that the rear of the H-
point device was placed at a 25 degree angle.
---------------------------------------------------------------------------

    \83\ Paine, M., Macbeth, A., and Henderson, M. (2003). The 
Danger to Young Pedestrians from Reversing Motor Vehicles. 18th 
International Technical Conference on the Enhanced Safety of 
Vehicles. Paper Number 466.
---------------------------------------------------------------------------

    Data from this test procedure were used to calculate vehicle 
ratings by considering several factors including the total visible area 
behind the vehicle; the visible distance across the rear of the 
vehicle; and the presence of backing aids such as proximity sensors and 
rearview camera systems. Consequently, the authors identified several 
vehicle design aspects that affect rear visibility, including a high 
bootlid (referred to as the ``trunk lid'' in the US); rear-mounted 
spare tires; rear head restraints; center high-mounted brake lights; 
rear mounted wipers; and rear spoilers.
    NHTSA believes the rear visibility assessment method outlined by 
these researchers has merit. However, further refinement may be 
desirable. For instance, a more accurate eye point for location of the 
laser beam would better simulate what a 50th percentile male would be 
able to see. The agency is undertaking research to examine the use of 
laser-based methods of measuring a vehicle's rear visibility 
characteristics.
Consumer Reports Linear Rear Blind Spot Measurement Method
    Consumer Reports evaluates vehicles for rear visibility and 
publishes the findings as part of their new vehicle reviews. In their 
August 2006 report, they examined vehicles to determine the closest 
distance at which a 28-inch object (approximating the height of a child 
less than 1 year old) could be detected behind a vehicle.\84\ During 
the evaluation, drivers \85\ were seated in the vehicle and asked to 
detect an object while it was moved outward from the rear of the 
vehicle along its centerline. The distance from the rear bumper at 
which the driver could detect the object was measured, and then these 
sight distances were published as consumer information.
---------------------------------------------------------------------------

    \84\ Consumer Reports (August, 2006). Blind-zone measurements. 
http://www.consumerreports.org/cro/cars/safety-recalls/mind-that-
blind-spot-1005/blindspot-measurements/index.htm.
    \85\ The heights of the subject drivers were 68 inches 
(approximate height for a 50th percentile adult male) and 61 inches 
(approximate height for a 5th percentile small female).
---------------------------------------------------------------------------

    Consumer Reports' data describe a rear sight distance as measured 
at the centerline of the vehicle, which may not accurately describe 
rear visibility across the entire width of the rear of the vehicle and 
therefore not fully address the risk of a backing crash. In addition, 
the use of human drivers, particularly a single driver of a particular 
height, to estimate rear visibility for a vehicle is likely to produce 
results that are subject to variability stemming from individual 
differences. While this information may be helpful to consumers, for 
the purposes of establishing a Federal regulation on rear visibility, 
NHTSA would be required to follow an approach that has demonstrated 
objectivity and repeatability.

[[Page 9507]]

NHTSA's Human-Based Rear Visibility Measurements
    In 2007, NHTSA measured the rear visibility characteristics of 44 
vehicles using human drivers to report the actual area around a vehicle 
where they could detect a 29.4-inch-tall test object.\86\ During the 
test procedure, the visual target was moved behind the vehicle over a 
grid of 1-foot squares spanning 110 feet longitudinally (including 90 
feet behind the vehicle's rear bumper) and 70 feet laterally (i.e., 35 
feet to either side of the vehicle's centerline). Points on the grid 
where the entire 3-inch reflector (comprising the top portion of the 
test object) was visible were recorded and combined to produce a 
graphical rear field of view representation for the vehicle. Visible 
areas around the vehicle were assessed for a 50th percentile male and 
5th percentile female driver. These driver sizes were chosen to acquire 
a range of visibility data in relation to driver height and because 
they have been used by other organizations 87 88 in similar 
visibility tests.
---------------------------------------------------------------------------

    \86\ Mazzae, E.N., Light Vehicle Rear Visibility Assessment, DOT 
HS 810 909, September 2008. NHTSA's visual target for this test was 
a traffic cone with a reflector atop; its height is representative 
of a 1-year-old child.
    \87\ See also Consumer Reports (August, 2006). Blind-zone 
measurements. http://www.consumerreports.org/cro/cars/safety-
recalls/mind-that-blind-spot-1005/blindspot-measurements/index.htm. 
Accessed 3/1/2006.
    \88\ See also Paine, M., Macbeth, A., and Henderson, M. (2003). 
The Danger to Young Pedestrians from Reversing Motor Vehicles. 18th 
International Technical Conference on the Enhanced Safety of 
Vehicles. Paper Number 466.
---------------------------------------------------------------------------

    NHTSA observed that physical characteristics among drivers can 
affect rear visibility. These characteristics include the occupant's 
torso breadth, physical flexibility (e.g., torso and neck rotational 
range), peripheral visual ability, visual acuity, and the presence of 
eye glasses.\89\ Additional differences relating to driver positioning 
while backing (e.g., raising the body up from the seat pan to achieve a 
higher vantage point), driver preferences regarding seat adjustment, 
and mirror positioning may also affect rear visibility. For example, 
based on a review of test data, it appears that the particular 5th 
percentile female driver involved in this testing may have been less 
restricted in her body movement (i.e., leaned or ``craned'' body more) 
when attempting to view the visual target. This resulted in a situation 
that for some vehicles, the measured minimum sight distance and average 
sight distance values were better for the shorter driver than for the 
taller driver.
---------------------------------------------------------------------------

    \89\ Note that when a driver wearing eye glasses turns to look 
over their right shoulder to see behind their vehicle, there is a 
point at which the line of sight can pass beyond the perimeter of 
the lens, at which point the driver loses the aid of the corrective 
lens.
---------------------------------------------------------------------------

NHTSA's Laser-Based Rear Visibility Measurement Procedure
    NHTSA's rear visibility research conducted in 2008 began with an 
effort to improve upon the previously used human-based rear visibility 
measurement procedure. Since any compliance test for the Federal motor 
vehicle safety standards is required by law to be repeatable and 
reproducible, enhancements were focused on improving this aspect of the 
measurement procedure. The agency considered known rear visibility 
measurement procedures, built upon the work by Paine et al.,\90\ and 
developed an enhanced version of that procedure that replaced the human 
driver previously used in rear visibility measurements with a laser-
based fixture. The enhanced procedure approximated the direct rear 
visibility of a vehicle for a 50th percentile male driver using a 
fixture that incorporated two laser pointing devices to simulate a 
driver's line of sight. One laser pointing device was positioned at the 
midpoint of a 50th percentile male's eyes when looking rearward over 
his left shoulder and the other device was placed at the midpoint of a 
50th percentile male's eyes when looking rearward over his right 
shoulder during backing.
---------------------------------------------------------------------------

    \90\ Paine, M., Macbeth, A., and Henderson, M. (2003). The 
Danger to Young Pedestrians from Reversing Motor Vehicles. 18th 
International Technical Conference on the Enhanced Safety of 
Vehicles. Paper Number 466.
---------------------------------------------------------------------------

    The use of a laser pointing device to simulate driver sight line 
was also used by Paine, et al.\91\ However, they used only a single eye 
point that was approximately at the side of a 50th percentile male 
driver's head. In addition, ISO 7397-2,\92\ which outlines a procedure 
for verifying the driver's 180-degree forward direct field of view for 
passenger cars, also uses a laser-based measurement technique. The use 
of two representative eye points and a wider measurement area have been 
proven to correlate well with backing crash risk \93\ and therefore may 
result in a more valid measurement method.
---------------------------------------------------------------------------

    \91\ Id.
    \92\ ISO 7397-2, Passenger cars--Verification of driver's direct 
field of view--Part 2: Test method, first edition, 1993-07-01.
    \93\ Partyka, S., Direct-View Rear Visibility and Backing Risk 
for Light Passenger Vehicles, (2008).
---------------------------------------------------------------------------

    More details of NHTSA's revised rear visibility measurement 
procedure using lasers are provided below.
1. Size of Rear Visibility Measurement Field
    The size of the field over which rear visibility is measured should 
encompass those areas critical to the avoidance of backover crashes. To 
evaluate the dimensions of this field, NHTSA measured rear blind zone 
area data for a variety of vehicles and compared these results with 
backing crash data for those vehicles. In addition, a Monte Carlo 
simulation analysis of relative backing crash risk as a function of 
pedestrian location was performed. The results of these analyses are 
summarized below.
    Data analysis was performed to assess the correlation between 
vehicles' rear blind zone areas measured using a 50th percentile male 
driver and the backing crash data for 21 vehicles.\94\ Results of this 
analysis for a portion of the field sizes assessed are summarized in 
Table 10 (Appendix D contains a table summarizing the complete set of 
areas assessed). Evidence of good correlation in this analysis is given 
by high correlation coefficient values and a low probability of 
occurrence by chance. All measurement field dimension combinations 
listed in Table 10 show good correlation with backing crashes. A 
similar preliminary analysis recently conducted by NHTSA using laser-
based rear blind zone areas measured for 60 vehicles over various 
measurement field sizes showed a 50 feet square field to be better 
correlated with backing crashes than narrower field size of the same 
longitudinal dimension.
---------------------------------------------------------------------------

    \94\ Mazzae, E.N., Light Vehicle Rear Visibility Assessment, DOT 
HS 810 909, September 2008. NHTSA's visual target for this test was 
a traffic cone with a reflector atop; its height is representative 
of a 1-year-old child.

[[Page 9508]]

 Table 10--Correlation Between Human-Based Rear Blind Zone Area Measured
   Over Various Field Sizes and Backing Crashes (Sorted by Correlation
                              Coefficient)
------------------------------------------------------------------------
                                                            Probability
 Measurement field dimensions  (width by    Correlation     occurred by
                 length)                    coefficient       chance
------------------------------------------------------------------------
50W x 10L...............................         0.60117          0.0039
40W x 10L...............................         0.60117          0.0039
30W x 10L...............................         0.58233          0.0056
30W x 50L...............................         0.55212          0.0095
40W x 40L...............................         0.54681          0.0103
30W x 40L...............................         0.53635          0.0122
20W x 40L...............................         0.52621          0.0143
50W x 50L*..............................         0.52375          0.0148
20W x 50L...............................         0.52367         0.0148
------------------------------------------------------------------------
* Blind zone area measured over a field this size was found by
  preliminary analysis of laser-based measurement data to be well
  correlated with backing crashes.

    Considering the assessment of backover crash risk by pedestrian 
location described in Section IV.E of this notice, the results 
presented in Figure 1 suggest that a measurement field centered behind 
the vehicle and approximately 12 feet wide by 36 feet long would 
address pedestrian locations having relative crash risks of 0.15 and 
higher. Given that the analysis described in Appendix A suggests that 
backover crash risk extends a fair distance (38 ft or more) out from 
the vehicle, it may result in a more valid characterization of rear 
visibility if a range similar to this were used for a rear visibility 
measurement field.
    For NHTSA's 2008 rear visibility measurement effort, a measurement 
field of 50 feet long by 50 feet wide test area was used to ensure that 
sufficient data were available for use in subsequent correlation 
analyses relating measurement field and backing crashes. However, based 
on a combination of the results of the three analyses summarized above, 
a field size centered behind the vehicle and having the dimensions of 
40 feet square or 50 feet is used on the analyses discussed in this 
section.
2. Coarseness of the Rear Visibility Measurement Field's Test Grid
    A measurement field covered by a test grid consisting of 1-foot 
squares was used. This level of grid detail has provided meaningful 
rear visibility data in past NHTSA testing, and has been used to 
produce rear blind zone area data that have been successfully 
correlated with backing crash risk.
3. Use of an H-Point Machine for Rear Visibility Measurement
    To facilitate a repeatable test procedure, an H-Point machine,\95\ 
used by the agency for many other standards and representing a 50th 
percentile adult male was used in place of a human driver for this 
measurement effort. The 50th percentile adult male approximates the 
midpoint for driver height, and has been used by other organizations 
\96, 97\ conducting similar visibility measurement research. An H-Point 
machine was selected to provide a standardized representation of the 
seated posture of an adult male driver. The H-point machine's standard 
configuration was modified to incorporate a fixture mounted in place of 
the device's neck to hold the laser pointing devices in specific 
positions to correspond to selected eye points for a 50th percentile 
adult male driver (as described below).
---------------------------------------------------------------------------

    \95\ SAE J826, Devices for Use in Defining and Measuring Vehicle 
Seating Accommodation, Rev. JUL95.
    \96\ See also Consumer Reports (August, 2006). Blind-zone 
measurements. http://www.consumerreports.org/cro/cars/safety-
recalls/mind-that-blind-spot-1005/blindspot-measurements/index.htm. 
Accessed 3/1/2006.
    \97\ See also Paine, M., Macbeth, A., and Henderson, M. (2003). 
The Danger to Young Pedestrians from Reversing Motor Vehicles. 18th 
International Technical Conference on the Enhanced Safety of 
Vehicles. Paper Number 466.
---------------------------------------------------------------------------

4. Rear Visibility Measurement Test Object Height
    NHTSA's rear visibility tests to date have been based on a test 
object height representing the approximate height of a 1-year-old 
child. As indicated earlier in this notice, 1-year-old children are the 
most frequent (approximately 26 percent of all backovers) victims of 
fatal backover incidents. The height chosen to represent a 1-year-old 
child in NHTSA's tests to date was determined by averaging standing 
height values from the Center for Disease Control's (CDC) growth chart 
\98\ (see Table 11 below) for a male and female 1-year-old child. The 
average height value obtained was 29.4 inches.
---------------------------------------------------------------------------

    \98\ 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).

                                                         Table 11--50th Percentile Child Height
--------------------------------------------------------------------------------------------------------------------------------------------------------
                          Age                                1         2        3         4         5         6         7         8        9        10
--------------------------------------------------------------------------------------------------------------------------------------------------------
Height--Girl...........................................    29.125      33.5     37.2     39.5       42.5     45.25     47.75     50.25     52.2     54.5
Height--Boy............................................    29.6        34       37.5     40.25      43       45.5      48        50.5      52.5    54.5
--------------------------------------------------------------------------------------------------------------------------------------------------------
Source: CDC, 2000.

5. Laser Detector (in Lieu of a Visual Target)
    To improve the efficiency of our test procedure, NHTSA's rear 
visibility measurement effort in 2008 used a different test object than 
used in prior measurements. This new test object incorporates a laser 
beam detector that automatically produces an audible signal when the 
laser beam, simulating the driver's line of sight, intersects with the 
laser detector. Since laser beams can

[[Page 9509]]

be difficult to detect with the human eye, even in low light 
conditions, use of a laser beam detector would improve both the 
accuracy and speed of test conduct.
    The laser detector target was constructed with a commercial laser 
detector mounted vertically on a post. The base of the post was a 12-
inch square of wood used to stabilize the fixture and center it within 
a 1-foot grid square. The target's detection field was horizontally 
centered with respect to the post and base. The bottom of the laser 
detector's approximately 2-inch tall detection field was aligned at a 
vertical height of 28 inches, to simulate a 30-inch overall detection 
height.
    For this approach to be usable and accommodate the 50 feet long 
test grid and all possible lengths of vehicles to be measured, the 
particular laser pointing device and laser beam detector were required 
to have performance ranges of at least 70 feet.
    An alternative approach, without a laser detector device, would be 
to rely on a test operator to visually confirm that the laser beam 
contacted the test object within the detection area while the test 
object was positioned within a particular location on the test grid.
6. Eye Midpoint Locations for Use in Positioning Laser Pointing Devices
    NHTSA researchers experimentally determined the most appropriate 
locations for the lasers used to represent the line of sight for a 
driver glancing over the right and left shoulder. Human eye locations 
for three male drivers of 50th percentile height were determined using 
photometric measurements while these drivers glanced at a cone 
positioned 25 feet behind a vehicle and approximately at its centerline 
and while looking directly (i.e., 90 degrees from forward) out the left 
and right sides of the vehicle. Photographs were taken from the rear 
and right (passenger) side of the vehicle for each of the three drivers 
and three vehicles. Driver eye positions for each vehicle were 
determined for both rear-looking glancing postures (rearward over the 
left and right shoulders) and both side-looking glancing postures (left 
and right). These eye positions were determined with respect to the 
vehicles' seats using a scale of rigid rulers. Researchers calculated 
an average left and right eye point locations to determine a midpoint 
between the left and right eye for each of the four postures. These 
midpoint values, which were used to identify locations of the laser 
pointing device to simulate a driver's line of sight, are provided in 
Table 12 below. NHTSA welcomes comments on the validity and 
appropriateness of these eye points for use in evaluating a vehicle's 
rear visibility for a 50th percentile male driver.

     Table 12--Left-Right Eye Midpoint Locations for Posture of Driver Glancing Rearward and to Either Side
----------------------------------------------------------------------------------------------------------------
                                        Longitudinal (distance
                                         forward of the head    Lateral offset from the   Vertical with respect
     Glancing rearward over the:         restraint's vertical    vertical centerline of    to H-Point (in.) (z)
                                           face) (in.) (x)         the seat (in.) (y)
----------------------------------------------------------------------------------------------------------------
Left shoulder........................                      3.5                      5.5                 26.5 \*\
Right shoulder.......................                      5.3                      7.0                 26.5 \*\
Left window (-90 degrees from                              7.6                     -5.5                 26.5 \*\
 forward)............................
Right window (90 degrees from                              7.6                      5.0                26.5 \*\
 forward)............................
----------------------------------------------------------------------------------------------------------------
\*\ Note: These measurements assume that the distance from the seat pan to the H-Point is 3.6 inches.

7. Vehicle Setup
    Vehicle setup conditions may be an important part of a repeatable 
visibility measurement procedure. Considerations which we used for our 
recent, laser-based measurements are detailed below.
    Fuel Tank--Ensure that the vehicle's fuel tank is filled to 
capacity, to provide a consistent fuel level (can affect vehicle 
pitch).
    Vehicle Tires--The vehicle's tires should be set to their 
recommended inflation pressures (can affect vehicle pitch).
    Vehicle Position on Test Grid--Position the vehicle on a flat, 
level test grid such that it is properly aligned (i.e., rear bumper 
flush with the `0' foot line, vehicle centered on the `0' longitudinal 
axis of the test grid).
    Vehicle Windows--The vehicle's windows should be closed, clean, and 
clear of obstructions (e.g., window stickers).
    H-Point Device Configuration--Place the H-Point device in the 
driver's seat and adjust the seat as follows:
     Install the H-Point machine in the vehicle per the 
installation procedure outlined in SAE J826.\99\
---------------------------------------------------------------------------

    \99\ SAE J826, Devices for Use in Defining and Measuring Vehicle 
Seating Accommodation, Rev. JUL95.
---------------------------------------------------------------------------

     Adjust the driver's seat to the longitudinal adjustment 
position recommended by the manufacturer for a 50th percentile adult 
male as specified in FMVSS Nos. 208,\100\ 212,\101\ 219 (partial),\102\ 
and 301 \103\ compliance testing. If this recommended adjustment 
setting is not available, position the seat at the midpoint of the 
longitudinal adjustment range. If no midpoint is selectable, then 
position the seat at the first notch rearward of the midpoint.
---------------------------------------------------------------------------

    \100\ 49 CFR 571.208, Standard No. 208; Occupant crash 
protection.
    \101\ 49 CFR 571.212, Standard No. 212; Windshield mounting.
    \102\ 49 CFR 571.219, Standard No. 219; Windshield zone 
intrusion.
    \103\ 49 CFR 571.301, Standard No. 301; Fuel system integrity.
---------------------------------------------------------------------------

     Adjust the driver's seat to the vertical adjustment 
position recommended by the manufacturer for a 50th percentile adult 
male as specified in FMVSS Nos. 208, 212, 219 (partial), and 301 
compliance testing. If this recommended adjustment setting is not 
available, position the seat at the lowest point of all vertical 
adjustment ranges present.
     Use the H-Point machine to adjust the driver's seat back 
angle at the vertical portion of the H-Point machine's torso weight 
hanger to that recommended by the manufacturer for a 50th percentile 
adult male as specified in FMVSS 208, 212, 219 (partial), and 301 
compliance testing. If this recommended adjustment setting is not 
available, adjust the seat back angle to 25 degrees, as specified in 
SAE J826.
     Adjust the driver's seat head restraint such that the 
distance from the H-Point to the topmost point of the head restraint, 
as measured along a line parallel to the seat back, is 32.5 
inches.\104\ If a distance of 32.5 inches is not attainable given the 
adjustment range of the head restraint or detent

[[Page 9510]]

positions, the closest detent position to that height should be used.
---------------------------------------------------------------------------

    \104\ This 32.5 inch measurement is based on sitting height of 
36.3 inches for 50th percentile adult males aged 20 and over. See 
CDC Web site at: http://www.cdc.gov/nchs/about/major/nhanes/
anthropometric_measures.htm.
---------------------------------------------------------------------------

     For any head restraints with longitudinal adjustment, the 
restraint should be positioned fully forward.
    Vehicle Seat Positioning--Adjust all seats in positions other than 
the driver's as follows:
     Vehicles with standard stowable second or third row seats 
should have all seats in an upright, occupant-ready position. This 
configuration provides a consistent approach for rear seat positioning 
to avoid vehicle-to-vehicle test differences. If a vehicle is offered 
with an optional original equipment third row seat, the vehicle should 
be measured in this seating configuration to assess the vehicle's rear 
visibility characteristics in this worst-case condition.
     For seats with longitudinally adjustable head restraints, 
the restraint should be positioned at the midpoint of longitudinal 
adjustment
     For seats with vertically adjustable head restraints, the 
restraint should be positioned in the lowest possible position. This 
configuration provides a consistent approach for head restraint 
positioning to avoid vehicle-to-vehicle test differences.
     For seats with an adjustable seat back angle, adjust the 
seat back angle to that recommended by the manufacturer for a driver's 
seat back angle position for a 50th percentile adult male as specified 
in FMVSS 208, 212, 219 (partial), and 301 compliance testing. If this 
recommended driver's seat back angle setting is not available, adjust 
the seat back angle to 25 degrees.
     Any rear seating position shoulder belts originating from 
the headliner (e.g., for use in rear center seating positions) should 
be latched into their receivers at the seat bite.
8. Measurement Procedure
    Once the vehicle has been properly set and the laser fixture has 
been set up, the laser devices are turned on and a pre-test is 
performed. To ensure that the laser device and laser detector are 
capable of performing the test, the laser device shall be properly 
mounted at the required driver eye point position (as indicated in 
Table 12), and aimed at the laser detector test object which shall be 
centered at a distance of 50 feet aft of the vehicle's bumper to 
determine whether the laser detector is able to sense the laser beam. 
This confirmation pre-test shall also be performed for the laser 
detector test object positioned at a distance of 50 feet from the rear 
bumper and 25 feet laterally to either side of the vehicle. If the 
laser detector detects the laser beam (e.g., as indicated by a ``beep'' 
or other confirming signal) in each of these three locations, then the 
equipment is considered to perform at an acceptable level for use in 
this test procedure.
    To complete the rear visibility measurements, the laser devices 
while maintaining the x, y, z coordinates may be manually or 
automatically maneuvered to pan the area behind the vehicle in both the 
vertical and horizontal directions. The vertical extent of the laser 
beam movement shall extend from the lower edge of the rear window to 
the horizon. The horizontal range of laser motion shall permit the 
evaluation of the direct visibility of the test object as positioned 
within 1 foot of the rear bumper and 25 feet to both sides of the 
vehicle's centerline.
    The test object is placed on the grid one time in each 1-foot 
square behind the vehicle. The test observer listens to determine 
whether the laser detector beeps (or otherwise signals) to indicate 
that the detector field has been contacted by a laser beam. The test 
object is considered visible if the laser detector beeps when a laser 
beam intersects with the test object. An operator records this 
measurement and repeats the prior steps for all positions in the grid.
Observations About Available Rear Visibility Measurement Procedures
    The above descriptions summarize NHTSA's knowledge of existing 
procedures for measuring vehicles' rear visibility. NHTSA seeks 
comments on the utility of these methods as objective rear visibility 
assessment methods.
    While the noted laser-based measurement method appears to provide a 
robust, objective test method, the repeatability of the method must be 
confirmed. Therefore, to further assess the utility of our laser-based 
rear visibility measurement procedure, we also assessed the 
repeatability of the test method as described in the following section.

B. Rear Visibility Measurement Method Variability

    To assess the variability of NHTSA's improved rear visibility test 
method using laser pointing devices, four test vehicles were measured 
using the laser-based rear visibility measurement protocol. The 
measurement procedure was completed four times for each vehicle, 
including repositioning of the vehicle on the test grid. Results of 
these measurements are illustrated in Figure 13. As indicated in Table 
13, the rear blind zone area data varied less than 3.2 percent of the 
measured value. This variability is believed to be due to the test 
vehicle's alignment of the rear bumper with respect to the lateral grid 
axis. More carefully aligning the vehicle on the test grid to ensure 
that the vehicle's centerline is aligned with the test grid's 
longitudinal axis will likely reduce variation to 2 percent or less.

[[Page 9511]]

[GRAPHIC] [TIFF OMITTED] TP04MR09.012

                                      Table 13--Rear Blind Zone Area Measurement Repeatability Results and Analysis
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                                                                                               Std dev/
                         Vehicle                           Test 1   Test 2   Test 3   Test 4    Avg      Std.     Min      Max    Range (max-     avg
                                                                                                         dev.                        min)      (percent)
--------------------------------------------------------------------------------------------------------------------------------------------------------
2005 Chrysler 300C......................................     1608     1631     1590     1604     1608     17.0     1590     1631          41         1.1
2006 BMW 330i...........................................     1523     1542     1533     1513     1528     12.5     1513     1542          29         0.8
2007 Cadillac Escalade..................................     1863     1800     1889     1887     1860     41.5     1800     1889          89         2.2
2007 Honda Odyssey......................................     1783     1834     1705     1739     1765     55.9     1705     1834         129         3.2
--------------------------------------------------------------------------------------------------------------------------------------------------------

    In summary, this rear visibility measurement procedure seems to 
provide for a controlled vehicle setup (for test consistency and 
repeatability) by its use of an automated test object, and dynamic 
laser movement.

C. Comparison of Human-Based Versus Laser-Based Rear Visibility 
Measurement Protocols

    NHTSA compared rear visibility data for 18 vehicles that were 
measured using both the human-based and laser-based rear visibility 
measurement procedures to assess the results (i.e., similar vehicle 
rankings, etc.) of the test procedure under consideration. This 
comparison found data from the two measurement methods to be different 
but correlated to a statistically significant degree.

D. Input From Industry Regarding Rear Visibility Measurement

    NHTSA received input from the Alliance for Automotive Manufacturers 
regarding the method for assessment for the purposes of assessing the 
need for a rear visibility enhancement countermeasure. The Alliance 
suggested a protocol similar to that used in FMVSS No. 111 for the 
measurement of the field of view of the interior rear mirror.\105\ This 
protocol would use a 95th percentile male driver. No additional details 
regarding a rear visibility measurement procedure were provided by the 
Alliance or any other group.
---------------------------------------------------------------------------

    \105\ Presentation to NHTSA, January 28, 2009 meeting; Alliance 
for Automotive Manufacturers. Available at Docket Number 2009-0041.
---------------------------------------------------------------------------

E. Questions

    (1) While a 50th percentile male body size was used for the rear 
visibility measurements outlined here, we note that FMVSS No. 111 
currently requires that the driver's eye reference point be at a 
nominal location appropriate for any 95th percentile male driver for 
the assessment of rearview mirror field of view compliance. We further 
note that under FMVSS No. 111 the driver's eye location for school bus 
mirror compliance testing is the eye location of a 25th percentile 
female driver. NHTSA requests comment on the use of the 50th percentile 
male driver size as a midpoint in terms of driver height and whether 
using multiple driver heights for these tests would cause undue 
hardship relative to the safety value of assessing different driver 
heights. Specific information regarding

[[Page 9512]]

additional cost, if any, that would be incurred by vehicle 
manufacturers due to the use of different driver sizes for these 
different portions of FMVSS No. 111 is requested.
    (2) NHTSA has been using seating position settings recommended by 
the vehicle manufacturers for agency crash tests. For most vehicles, 
the vertical seat position setting recommended for seats with vertical 
adjustability is the lowest position. NHTSA seeks comment on whether 
this setting is the most suitable position for a 50th percentile male, 
or if a midpoint setting would be more appropriate for measuring rear 
visibility. NHTSA also seeks comment on whether the specific crash test 
seating specifications used are the most appropriate for this context.
    (3) NHTSA seeks comment on the placements of head restraints. For 
example, would our test procedure result in the elimination of rear 
head restraints or a reduction in their size? If so, please identify 
the affected vehicles and explain why the rear head restraints 
particularly impair visibility in those vehicles. Similarly, NHTSA 
seeks comment on the approach to setting the longitudinal position of 
all adjustable head restraints for rear visibility measurements. While 
longitudinally adjustable head restraints positioned fully forward may 
minimize the chance of whiplash, a more reasonable option for this test 
may be to position the head restraint at the midpoint of the 
longitudinal adjustment range.
    (4) In our testing, we found that the laser beam is difficult to 
detect visually. Therefore, we used the laser detector. NHTSA invites 
comment on the availability of other options for detecting the laser 
beam as used in this test that does not involve the use of an 
electronic laser detector.
    (5) For locating the laser devices at the selected driver eye 
points, is there another device besides the H-point device which can be 
utilized for this purpose or should the agency? For simplicity, should 
eye points be indicated in a similar fashion as is currently in FMVSS 
No. 111 for school bus testing in which a single eye point is located 
at a specified distance from the seat cushion/seat back intersection 
and within a 6-inch semi-circular area?

XI. Options for Assessing the Performance of Rear Visibility 
Countermeasures

    To assess the minimum performance of a required rear visibility 
enhancement countermeasure, a compliance test would need to be 
developed. This test would serve to assess whether the system permits 
obstacles and standing children in the path of a backing vehicle to be 
detected over a minimum required area. Considerations that the agency 
has identified which may be necessary for this new compliance test are 
described below.

A. Countermeasure Performance Test Object

    A test object may be needed to assess whether the countermeasure 
functions over a specified area. Based on the crash data and our 
testing to date, we have used a test object with an approximate height 
of 30 inches (0.762 meters). As indicated earlier, this height 
corresponds to the average height of a 1-year-old child. To further 
simulate the appearance of a 1-year-old child, some have suggested 
other dimensional characteristics. Based on our research we have found 
that that the object would need to be cylindrical in shape with a 
diameter of 5 inches, to represent the breadth of the average 1-year-
old child's head.\106\
---------------------------------------------------------------------------

    \106\ Henry Dreyfuss Associates (2002). The Measure of Man and 
Woman; Human Factors in Design (rev.). New York: John Wiley & Sons.
---------------------------------------------------------------------------

    Depending on the type of countermeasure, the composition of the 
test object may be important. For example, rearview video systems would 
display images of objects of all possible material types, but 
ultrasonic and radar sensors are better at detecting some materials 
than others. NHTSA is aware of the requirement detailed in ISO 17386 
\107\ for use of a cylinder composed of polyvinyl chloride (PVC) pipe 
to test the detection performance of ultrasonic parking aids. NHTSA 
welcomes input regarding all aspects of the test object.
---------------------------------------------------------------------------

    \107\ ISO 17386:2004 Transport information and control systems--
Manoeuvring Aids for Low Speed Operation (MALSO)--Performance 
requirements and test procedures.
---------------------------------------------------------------------------

    The Alliance for Automotive Manufacturers has indicated to NHTSA 
that their suggestion is to use a cylindrical test object with a height 
of 1 meter (39.37 inches) and a diameter of 0.3 meters (11.3 
inches).\108\ No requirements for material composition of the test 
object were suggested by the Alliance.
---------------------------------------------------------------------------

    \108\ Presentation to NHTSA, January 28, 2009 meeting; Alliance 
for Automotive Manufacturers. Available at Docket Number 2009-0041.
---------------------------------------------------------------------------

B. Countermeasure Performance Test Area

    One possible compliance test area can be identified using the 
results of the Monte Carlo simulation (illustrated in Figure 1 and 
described in Appendix A) that examined backover crash risk as a 
function of a pedestrian's location behind a vehicle.\109\ NHTSA used 
these results to define an area behind a vehicle that must be visible 
to the driver. Based on these results, an area over which the test 
object should be visible could be defined to include an area 8 feet 
wide at the vehicle's rear bumper that widens symmetrically along 
diagonal lines of 45 degrees with respect to the vertical plane of the 
vehicle's rear bumper and extending outward from the vehicle's rear 
corners. The maximum longitudinal range of this required visible area 
is 40 feet, as shown in Figure 14.
---------------------------------------------------------------------------

    \109\ See Appendix B, Method for Assessment of Backover Crash 
Risk by Pedestrian Location.
---------------------------------------------------------------------------

BILLING CODE 4910-59-P

[[Page 9513]]

[GRAPHIC] [TIFF OMITTED] TP04MR09.013

BILLING CODE 4910-59-C

[[Page 9514]]

    Alternatively, the test area could be defined based on the results 
of the above mentioned Monte Carlo analysis, as well as the assessments 
of the correlation between vehicles' rear blind zone areas and backing 
crash data. The test area suggested by the combination of results of 
these three analyses is one that is centered behind the vehicle and 
having the dimensions of 40 feet square or 50 feet square.
    The Alliance for Automotive Manufacturers has indicated to NHTSA 
that their suggestion is to use a test area composed of 9 test object 
locations behind the vehicle.\110\ The 9 test object locations would 
consist of 3 rows of 3 locations. The 3 rows would be positioned with 
one at the rear bumper, and two others positioned 1.5 meters and 3.0 
meters aft of the rear bumper. The 3 lateral locations would consist of 
one at each lateral edge of the vehicle and the third at the vehicle's 
longitudinal centerline. By this scheme, the test area size would be 
based on each vehicle model's individual width, and therefore may be 
different for all vehicle models.
---------------------------------------------------------------------------

    \110\ Presentation to NHTSA, January 28, 2009 meeting; Alliance 
for Automotive Manufacturers. Available at Docket Number 2009-0041.
---------------------------------------------------------------------------

C. Countermeasure Performance Test Procedure

    The test procedure currently used for school bus mirrors (section 
13, ``School bus mirror test procedures'' of FMVSS No. 111, ``Rearview 
mirrors'') \111\ could be modified and used to determine countermeasure 
performance. For example, a still photography camera placed with the 
imaging sensor located at a midpoint eye location for a 50th percentile 
male (rather than a 95th percentile male), could be used to photograph 
the test objects as they are displayed in the countermeasure system's 
visual display. As is done now with cones in rear visibility 
measurements, for all specified locations of the test object on the 
test grid, at least a 3-inch tall by 3-inch wide portion of the test 
object would be required to be visible in order for the rear visibility 
enhancement system to be deemed compliant. This minimum detection area 
would represent the area that would need to be visible to adequately 
identify the test object.
---------------------------------------------------------------------------

    \111\ 49 CFR 571.111, Standard No. 111, Rearview Mirrors.
---------------------------------------------------------------------------

D. Questions

    (1) NHTSA invites comments on the need for and adequacy of the 
described area which rear visibility countermeasure systems may be 
required to detect obstacles. NHTSA is particularly interested in any 
available data that may suggest an alternative area behind the vehicle 
over which a rear visibility enhancement countermeasure should be 
effective? Is the described area of coverage unrealistically large? Is 
it adequate to mimic real world angles at which children may approach 
vehicles?
    (2) Is it reasonable to define the limits of the test zone such 
that it begins immediately behind the rear bumper for the test object 
defined here or should a gap be permitted before the visibility zone 
begins? What additional factors should the agency consider in defining 
the zone?
    (3) NHTSA requests comments on potentially requiring only the 
perimeter of the specified area to be tested for rear visibility 
enhancement systems. For video-based rear visibility countermeasure 
systems, NHTSA assumes that confirming the visibility of the test 
object over the perimeter of the required area is sufficient, since a 
system able to display the object at the perimeter of the required area 
should also be able to display the object at all points in between the 
extremities. Is this a reasonable assumption?
    (4) Would vehicles with rearview video cameras mounted away from 
the vehicle centerline have the ability to detect the test object over 
the area under consideration? Is there flexibility to relocate such 
off-center cameras to meet the requirements under consideration, if 
necessary?
    (5) NHTSA seeks comment as to the availability of any mirrors that 
may have a field of view that encompasses a range of 50 feet, as well 
as the quality of image that might be provided over such a range. How 
different is the image size and resolution, and how significant are the 
differences to the mirrors' potential effectiveness?
    (6) If a gap is permitted behind the vehicle before the visibility 
zone begins, how will systems prevent children who may be immediately 
behind a vehicle from being backed over?
    (7) NHTSA seeks input on what level of ambient lighting would be 
appropriate to specify for conduct of this compliance test. What other 
environmental and ambient conditions, if any, should the agency include 
in the test procedure?
    (8) NHTSA invites input regarding the composition of the 
countermeasure compliance test object and the types of technologies 
that are likely to be able to provide coverage of the related test 
area.

XII. Options for Characterizing Rear Visibility Countermeasures

    Existing rear visibility technologies, which formed the basis for 
NHTSA's effectiveness estimates, already contain certain performance 
levels specified by vehicle manufacturers. Some of these specifications 
may be necessary to ensure that our effectiveness estimates will be 
applicable to real-world crashes and to prevent for inferior systems 
from entering the fleet. However, NHTSA is not aware of consensus 
industry specifications (e.g., SAE standards) or published recommended 
practices for rear visibility enhancement systems other than mirrors 
that may serve this purpose. While FMVSS No. 111 contains performance 
specifications for convex mirrors, the mirror specifications contained 
therein may not be adequate for this application. As such, certain 
performance specifications may be necessary in order to ensure adequate 
system effectiveness. NHTSA solicits comment on whether the performance 
aspects we have identified are appropriate or whether additional 
specifications, particularly for electronic image-based visual 
displays, should be considered. NHTSA has not evaluated these 
performance specifications nor have we developed possible compliance 
tests for them.

A. Options for Display Characteristics

    Given that a particular rear visibility countermeasure technology 
has not been specified, the type of visual display associated with a 
rear visibility countermeasure has the potential to take a variety of 
forms. Such visual displays may include mirrors, flashing lights from 
sensor-based rear object detection system, or a video-based image 
display. Some characteristics relevant to possible visual display types 
are described below.
Performance Criteria Which May be Needed for All Rear Visibility 
Enhancement Countermeasure Displays (e.g., Rearview Video System 
Displays, Mirrors, and Electronic Warning Displays)
    Overall display size--The minimum overall image size should be 
defined to ensure that drivers will be able to detect small children in 
the visual display. If the image size is too small, the effectiveness 
of the system may be impacted by a driver's inability to identify a 
child or other object.
    Image resolution--It may be necessary to define the minimum image 
resolution so that drivers will be able to identify objects in the 
display.
    Image distortion--A maximum allowable distortion parameter may be

[[Page 9515]]

necessary to ensure that image quality is sufficient to allow drivers 
to accurately identify objects located behind the vehicle.
    Image minification--To ensure that objects behind the vehicle 
appear in the image of the area behind the vehicle as presented by the 
countermeasure's display with sufficient size to allow them to be 
identified by drivers, a maximum allowable minification level may be 
necessary.
    Environmental performance--It may be necessary to specify minimum 
environmental requirements under which systems would be expected to 
operate in common real world conditions.
Additional Performance Criteria Which May be Needed for Electronic 
Visual Displays (e.g., Rearview Video Systems, Electronic Warning 
Displays)
    Display location--In order to facilitate a driver's effective use 
of an electronic visual display, it may be beneficial to specify a 
permitted location for the display unit and image. For example, a 
rearview video image present in the interior rearview mirror must be 
displayed on the left side of the mirror so that the distance between 
the driver and image is not too large.
    Overall display size--For electronic, rearview video system 
displays, NHTSA is considering specifying a minimum image size of 3.25 
inches measured diagonally for an electronic visual display with aspect 
ratio of 4:3 \112\ (or approximately 4-inch diagonal size for 16:9 
aspect ratio displays).
---------------------------------------------------------------------------

    \112\ General Motors, SAE Government and Industry Meeting, May 
2008, oral presentation.
---------------------------------------------------------------------------

    Brightness--A minimum brightness value \113\ may be necessary to 
ensure that the display image can be seen by drivers in a wide variety 
of ambient conditions, such as glare from sunlight or ambient light.
---------------------------------------------------------------------------

    \113\ Measured in cd/m\2\.
---------------------------------------------------------------------------

    Contrast ratio--Minimum contrast ratio may be necessary to ensure 
that the display image can be seen by drivers in a wide variety of 
ambient conditions.
    Image response time--A minimum response time for the system to 
display an image of the area behind the vehicle may be necessary to 
enable a driver to engage the system while backing. NHTSA is 
considering a maximum of 1.25 seconds based on our research to 
date.\114\
---------------------------------------------------------------------------

    \114\ 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.
---------------------------------------------------------------------------

    Image ``linger'' time--To limit unintended distraction to drivers, 
the maximum image linger time (i.e., the time that the visual display 
remains on after the vehicle's transmission has been shifted out of 
reverse gear), may be specified. Some linger time is 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). NHTSA is considering a minimum of 4 seconds but not more 
than 8 seconds of linger time is appropriate after the vehicle is 
shifted from the reverse position.

Options for Other Display Characteristics

    NHTSA does not believe that a malfunction telltale is necessary for 
rearview video systems, since video camera or visual display failure 
would be indicated by the apparent lack of image presented in the 
visual display. We invite comments on this point and any evidence that 
would suggest that such an indicator may be necessary.

B. Options for Rearview Video System Camera Characteristics

    Currently, NHTSA does not have data which could be used to 
establish minimum specifications for a rearview video system's camera. 
However, based upon our knowledge of the current technology the agency 
believes that requirements for the following categories might be 
necessary: Low light performance requirements; resolution; and 
environmental performance limits/ranges.

C. Questions

    (1) Are there any existing industry consensus standards for rear 
visibility enhancement systems which address the parameters outlined in 
this section? Are there any ongoing efforts to develop such industry 
consensus standards? If so, when will the standards be published?
    (2) Are there additional parameters which should be specified to 
define a rear visibility enhancement system? What should the minimum 
specified performance be for each parameter?
    (3) Are future rear visibility systems anticipated which may have 
significantly different visual display types that may require other 
display specification parameters?

XIII. Conclusion

    In developing this notice, NHTSA tried to address the concerns of 
all stakeholders. Your comments will help us develop a rearward 
visibility standard to be included as part of FMVSS No. 111. We invite 
you to provide different views on the questions we ask, new approaches 
and technologies about which we did not ask, new data, insight as to 
how this notice may affect you, or other relevant information. We 
welcome your views on all aspects of this notice but we especially 
request comments on the specific questions articulated throughout this 
document.

XIV. 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.
    Please submit two copies of your comments, including the 
attachments, to Docket Management at the address given above under 
ADDRESSES.
    Comments may also 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.
    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

[[Page 9516]]

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 
the Internet. To read the comments on the Internet, go to http://
www.regulations.gov. Follow the online instructions for accessing the 
dockets.
    Please note that even after the comment closing date, we will 
continue to file relevant information in the Docket as it becomes 
available. Further, some people may submit late comments. Accordingly, 
we recommend that you periodically check the Docket for new material.

XV. Rulemaking Analyses and Notices

Executive Order 12866 and DOT Regulatory Policies and Procedures

    Executive Order 12866, ``Regulatory Planning and Review'' (58 FR 
51735, October 4, 1993), provides for making determinations whether a 
regulatory action is ``significant'' and therefore subject to OMB 
review and to the requirements of the Executive Order. The Order 
defines a ``significant regulatory action'' as one that is likely to 
result in a rule that may:
    (1) Have an annual effect on the economy of $100 million or more or 
adversely affect in a material way the economy, a sector of the 
economy, productivity, competition, jobs, the environment, public 
health or safety, or State, local, or Tribal governments or 
communities;
    (2) Create a serious inconsistency or otherwise interfere with an 
action taken or planned by another agency;
    (3) Materially alter the budgetary impact of entitlements, grants, 
user fees, or loan programs or the rights and obligations of recipients 
thereof; or
    (4) Raise novel legal or policy issues arising out of legal 
mandates, the President's priorities, or the principles set forth in 
the Executive Order.
    We have considered the potential impact of this ANPRM under 
Executive Order 12866 and the Department of Transportation's regulatory 
policies and procedures. As discussed above, there are a number of 
considerations and technologies that can be applied to address the 
issue of backovers and the agency lacks the necessary information to 
develop a proposal at this time. Based on the information we have, we 
developed this notice and placed in the docket a Preliminary Regulatory 
Impact Analysis to facilitate public input. Therefore, we have not yet 
determined whether or not this rulemaking will be economically 
significant under Executive Order 12866. However, this rulemaking 
action has been determined to be ``significant'' under the Department 
of Transportation's Regulatory Policies and Procedures (44 FR 11034; 
February 26, 1979) and has been reviewed by the Office of Management 
and Budget.

Regulatory Flexibility Act

    Pursuant to the Regulatory Flexibility Act, 5 U.S.C. 601 et seq., 
no analysis is required for an ANPRM. However, vehicle manufacturers 
and equipment manufacturers are encouraged to comment if they identify 
any aspects of the potential rulemaking that may apply to them.

Executive Order 13132 (Federalism)

    NHTSA has examined today's ANPRM pursuant to Executive Order 13132 
(64 FR 43255, August 10, 1999) and concluded that no additional 
consultation with States, local governments or their representatives is 
mandated beyond the rulemaking process at this time. The agency has 
concluded that the document at issue does not have federalism 
implications because it does not have ``substantial direct effects on 
the States, on the relationship between the national government and the 
States, or on the distribution of power and responsibilities among the 
various levels of government.''
    NHTSA's safety standards can have preemptive effect in at least two 
ways. First, the National Traffic and Motor Vehicle Safety Act contains 
an express preemption provision: ``When a motor vehicle safety standard 
is in effect under this chapter, a State or a political subdivision of 
a State may prescribe or continue in effect a standard applicable to 
the same aspect of performance of a motor vehicle or motor vehicle 
equipment only if the standard is identical to the standard prescribed 
under this chapter.'' 49 U.S.C. 30103(b)(1). It is this statutory 
command that would unavoidably preempt State legislative and 
administrative law, not today's rulemaking, so consultation would be 
unnecessary.
    We are aware that, depending on the nature of the proposal 
ultimately adopted, federalism implications could arise. Currently, 
there is no Federal requirement regarding visibility of the area 
directly behind a passenger vehicle. As a result, any State laws or 
regulations that seek to regulate this aspect of performance would not 
currently be preempted by Federal law. However, if NHTSA issues a 
standard on the same aspect of performance, those State laws and 
regulations would be preempted if they differed from the Federal 
requirements. Thus, the possibility of statutory preemption of State 
laws and regulations does exist. At this time, we do not know of any 
State laws or regulations that currently exist that are potentially at 
risk of being preempted, but in this document do request comment on any 
existing or planned laws or regulations that would fall into this 
category.
    Second, the Supreme Court has recognized the possibility of implied 
preemption: State requirements imposed on motor vehicle manufacturers, 
including sanctions imposed by State tort law, can stand as an obstacle 
to the accomplishment and execution of a NHTSA safety standard. When 
such a conflict is discerned, the Supremacy Clause of the Constitution 
makes the State requirements unenforceable. See Geier v. American Honda 
Motor Co., 529 U.S. 861 (2000). NHTSA has considered today's ANPRM and 
does not currently foresee any potential State requirements that might 
conflict with it. Without any conflict, there could not be any implied 
preemption.

Executive Order 12988 (Civil Justice Reform)

    With respect to the review of the promulgation of a new regulation,

[[Page 9517]]

section 3(b) of Executive Order 12988, ``Civil Justice Reform'' (61 FR 
4729, February 7, 1996) requires that Executive agencies make every 
reasonable effort to ensure that the regulation: (1) Clearly specifies 
the preemptive effect; (2) clearly specifies the effect on existing 
Federal law or regulation; (3) provides a clear legal standard for 
affected conduct, while promoting simplification and burden reduction; 
(4) clearly specifies the retroactive effect, if any; (5) adequately 
defines key terms; and (7) addresses other important issues affecting 
clarity and general draftsmanship under any guidelines issued by the 
Attorney General. This document is consistent with that requirement.
    Pursuant to this Order, NHTSA notes as follows. The preemptive 
effect of this document is discussed above. NHTSA notes further that 
there is no requirement that individuals submit a petition for 
reconsideration or pursue other administrative proceeding before they 
may file suit in court.

Protection of Children From Environmental Health and Safety Risks

    Executive Order 13045, ``Protection of Children from Environmental 
Health and Safety Risks'' (62 FR 19855, April 23, 1997), applies to any 
rule that: (1) Is determined to be ``economically significant'' as 
defined under Executive Order 12866, and (2) concerns an environmental, 
health, or safety risk that the agency has reason to believe may have a 
disproportionate effect on children. If the regulatory action meets 
both criteria, the agency must evaluate the environmental health or 
safety effects of the planned rule on children, and explain why the 
planned regulation is preferable to other potentially effective and 
reasonably feasible alternatives considered by the agency.
    While this document does not make any changes with regard to the 
standard at issue, the rulemaking is intended, in large part, to 
address a safety concern that is particularly applicable to young 
children. In response to the executive order and in alignment with the 
agency's policies, we have tailored our research efforts addressed in 
this document to be particularly sensitive to the needs of children. 
These steps have included, but are not limited to, analyzing accident 
cases that involve children and designing testing procedures and 
performance criteria with particular emphasis on the ultimate goal of 
detecting and preventing accidents involving the youngest children.

Paperwork Reduction Act

    Under the Paperwork Reduction Act of 1995 (PRA), a person is not 
required to respond to a collection of information by a Federal agency 
unless the collection displays a valid OMB control number. There is not 
any information collection requirement associated with this ANPRM.

National Technology Transfer and Advancement Act

    Section 12(d) of the National Technology Transfer and Advancement 
Act of 1995 (NTTAA), Public Law 104-113, (15 U.S.C. 272) directs the 
agency to evaluate and use voluntary consensus standards in its 
regulatory activities unless doing so would be inconsistent with 
applicable law or is otherwise impractical. Voluntary consensus 
standards are technical standards (e.g., materials specifications, test 
methods, sampling procedures, and business practices) that are 
developed or adopted by voluntary consensus standards bodies, such as 
the Society of Automotive Engineers. The NTTAA directs us to provide 
Congress (through OMB) with explanations when we decide not to use 
available and applicable voluntary consensus standards. There are no 
voluntary consensus standards developed by voluntary consensus 
standards bodies pertaining to this ANPRM.

Unfunded Mandates Reform Act

    The Unfunded Mandates Reform Act of 1995 requires agencies to 
prepare a written assessment of the costs, benefits and other effects 
of proposed or final rules that include a Federal mandate likely to 
result in the expenditure by State, local or tribal governments, in the 
aggregate, or by the private sector, of more than $100 million annually 
(adjusted for inflation with base year of 1995). This ANPRM would not 
result in expenditures by State, local or tribal governments, in the 
aggregate, or by the private sector in excess of $100 million annually. 
However, given the cost estimates of some of the technologies at issue, 
most relevantly RV video systems, it is very possible that the total 
cost of a proposed rule could substantially exceed $100 million. Given 
that, the agency has prepared a preliminary assessment of some of the 
possible costs of the technologies investigated in this ANPRM.

National Environmental Policy Act

    NHTSA has analyzed this rulemaking action for the purposes of the 
National Environmental Policy Act. The agency has determined that 
implementation of this action will not have any significant impact on 
the quality of the human environment.

Executive Order 13211

    Executive Order 13211 (66 FR 28355, May 18, 2001) applies to any 
rulemaking that: (1) Is determined to be economically significant as 
defined under E.O. 12866, and is likely to have a significantly adverse 
effect on the supply of, distribution of, or use of energy; or (2) that 
is designated by the Administrator of the Office of Information and 
Regulatory Affairs as a significant energy action. This rulemaking is 
not subject to E.O. 13211.

Plain Language

    Executive Order 12866 and the President's memorandum of June 1, 
1998, require each agency to write all rules in plain language. 
Application of the principles of plain language includes consideration 
of the following questions:
     Have we organized the material to suit the public's needs?
     Are the requirements in the rule clearly stated?
     Does the rule contain technical language or jargon that 
isn't clear?
     Would a different format (grouping and order of sections, 
use of headings, paragraphing) make the rule easier to understand?
     Would more (but shorter) sections be better?
     Could we improve clarity by adding tables, lists, or 
diagrams?
     What else could we do to make the rule easier to 
understand?
    If you have any responses to these questions, please include them 
in your comments on this ANPRM.

Regulatory Identifier Number (RIN)

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

Privacy Act

    Anyone is able to search the electronic form of all comments 
received into any of our dockets by the name of the individual 
submitting the comment (or signing the comment, if submitted on behalf 
of an association, business, labor union, etc.). You may review DOT's 
complete Privacy Act Statement in the Federal Register published on 
April 11, 2000 (Volume

[[Page 9518]]

65, Number 70; Pages 19477-78) or you may visit http://
www.regulations.gov.

    Issued on: February 26, 2009.
Stephen R. Kratzke,
Associate Administrator for Rulemaking.

Appendix A--Methodology for Assessing Backover Crash Risk by Pedestrian 
Location

    Monte Carlo simulation was used to calculate a probability-based 
risk weighting for each square in a grid of 30-cm squares behind the 
vehicle. The grid of 30-cm squares extended 27 m back from the rear 
edge of the rear bumper of the vehicle, 6 m forward of the rear 
bumper, and 10.5 m to the left and to the right of the longitudinal 
centerline of the vehicle, resulting in a total of 7,700 30-cm grid 
squares. The probability-based risk weightings for each grid square 
were based on the number of pedestrian-vehicle backing crashes 
predicted by the simulation for trials for which the pedestrian was 
initially (i.e., at the time that the vehicle began to back up) in 
the center of one square of the grid of 30-cm squares. For each 
Monte Carlo simulation trial, the pedestrian was initially placed in 
the center of one square of the grid of 30-cm squares. A total of 
1,000,000 Monte Carlo simulation trials were run with the pedestrian 
initially in the center of each square. Since the Monte Carlo 
simulation used had left-right symmetry, mirroring was used to 
increase the effective number of simulation trials to 2,000,000 for 
each grid square.
    Important assumptions were made about the behavior of the driver 
and the pedestrian for this analysis. The vehicle and pedestrian 
were assuming to begin moving at the same time and were assumed to 
be completely unaware of each other. Therefore, the motions of the 
vehicle and pedestrian were totally independent of the each other. 
Note that it was possible for the pedestrian to walk or run into the 
vehicle. If the impact was with the rear of the vehicle, a back-over 
incident was considered to have resulted. If the impact was with the 
side or front of the vehicle, the crash was not counted as a backing 
crash for the purposes of this analysis.

Vehicle Descriptors

    Four descriptors were used to define the simulated vehicle in 
this analysis. The width of the vehicle was assumed to be 6.0 feet 
for this analysis. The distance that the vehicle backed up during 
each backing trial was determined by a random draw from a three-
parameter Weibull probability distribution for distance backed that 
was based on data from the ``On-Road Study of Drivers' Use of 
Rearview Video Systems'' study.\115\ To simplify the analysis this 
simulation assumed that the vehicle backed up at a constant speed 
based on a random draw from a three-parameter Weibull probability 
distribution also based on NHTSA's research data.\116\
---------------------------------------------------------------------------

    \115\ 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.
    \116\ Id.
---------------------------------------------------------------------------

    Since backing maneuvers frequently involve turning, any backing 
trial more than 25 feet long was assumed to possibly include a turn. 
To determine whether the vehicle turned to the left, went straight, 
or turned to the right during each backing trial, a uniformly 
distributed random number was drawn. There was a 40 percent 
probability of a left turn, a 40 percent probability of a right 
turn, and a 20 percent probability of a no turn. The turn, if there 
was one, did not commence until after 25 feet of backing or 30 feet 
from the end of the back, whichever was greater. Once turning 
commenced the rear bumper of the vehicle traveled around a 20 foot 
radius circle. Since the maximum distance in the turn was 30 feet, 
the angle which the vehicle turned through ranged from 0 to 85.9 
degrees (1.5 radians).

Pedestrian Descriptors

    The pedestrian was modeled in the horizontal plane as a circle 
of radius 0.375 feet. To simplify the analysis, the pedestrian was 
assumed to move at constant speed and direction. The angle of 
pedestrian travel was determined by a random draw from a uniform 
probability distribution extending from -180.0 to +180.0 degrees. 
Walking speed was determined by a random draw from a triangular 
probability distribution ranging from 0.0 to 5.0 mph.
    To define the position of the pedestrian behind the vehicle, 
axes were assigned to the grid. An X axis was set up pointing 
straight back along the longitudinal centerline of the vehicle with 
its origin at the rear bumper of the vehicle. A Y axis was set up 
pointing along the (assumed straight) rear edge of the rear bumper 
with its origin at the center of the rear bumper. Positive Y values 
were on the driver's side of the vehicle. The pedestrian was always 
started at the center of one of the 1-foot grid squares. Therefore, 
the initial positions of the pedestrian, in both X and Y, were 
always at a half foot mark. All possible initial pedestrian 
positions were simulated. Therefore, the initial pedestrian X 
positions ranged from 0.5 to 49.5 feet in 1.0-foot increments. 
Similarly, the initial pedestrian Y positions ranged from -9.5 to 
9.5 feet also in 1.0-foot increments.

Additional Simulation Information

    As was previously mentioned, a total of 1,000,000 Monte Carlo 
simulation trials were run with the pedestrian initially in the 
center of each square. Each trial simulated 60.0 seconds of time 
unless the pedestrian collided with the vehicle or the vehicle 
completed its movement first. Actual backing events do not last for 
60.0 or more seconds. The longest backing event out of the 6,185 in 
the ``On-Road Study of Drivers' Use of Rearview Video Systems'' 
study \117\ data set was 52.8 seconds long. However, for the 
simulation, both the backing distance and average backing speed were 
determined independently of each other from Weibull probability 
distributions. This is actually not correct; statistical analyses of 
the ``On-Road Study of Drivers' Use of Rearview Video Systems'' 
study \118\ data set indicates that for real driving, as backing 
distance increases so does average backing speed. However, it was 
decided to accept the independence of the backing distance and 
average backing speed so as to simplify the simulation. As a result, 
1.1 percent of all simulated backing trials had not been completed 
after 60.0 seconds of simulation. For the purposes of this analysis 
it was decided that the normalization process would probably 
adequately account for not otherwise dealing with this issue.
---------------------------------------------------------------------------

    \117\ 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.
    \118\ 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.
---------------------------------------------------------------------------

    A count was made of all trials for which the pedestrian collided 
with the rear bumper of the vehicle. If the pedestrian collided 
first with either the front or sides of the vehicle, then this was 
not counted as a backing collision.
    After completion of the simulation for all grid squares, a 
normalization of the backing crash counts for each grid square was 
performed. The normalization converted each grid square's crash 
count into its probability of crash relative to the probability of 
crash for the grid squares for which a crash was most likely to 
occur. The grid squares for which a crash was most likely to occur 
were the two directly behind the bumper in the center of the 
vehicle, i.e., the grid squares at (0.5 ft, 0.5 ft) and at (0.5 ft, 
-0.5 ft). The relative probability of crash for these two grid 
squares was set to 1.0. For all other grid squares, the crash count 
was divided by the crash count for grid square (0.5, 0.5). Note that 
due to left-right mirroring, the grid squares at (0.5, 0.5) and at 
(0.5, -0.5) both had the same crash counts. This resulted in a 
probability of crash relative to the probability of crash for the 
grid squares at (0.5, 0.5) and at (0.5, -0.5). Since all grid 
squares were subjected to the same simulation imperfections, this 
first normalization was expected to reduce the impact of these 
imperfections of the simulation results.
    Figure 1 of this notice summarizes the calculated relative crash 
risk for each grid square. Note that the white shaded area does not 
have a zero backover risk; it merely has a low (less than 12.5 
percent of the maximum) risk.
    This analysis shows that the probability of crash decreases 
rapidly as the pedestrian's initial location is moved back, further 
away, from the rear bumper of the vehicle. There are substantial 
side lobes, giving pedestrians a reasonable chance of being hit even 
though they were not initially directly behind the vehicle.

Appendix B--Method for On-Road Study of Drivers' Use of Rearview Video 
Systems

    Drivers' use of rearview video systems was observed during 
staged and naturalistic backing maneuvers to determine whether

[[Page 9519]]

drivers look at the RV display during backing and whether use of the 
system affects backing behavior.\119\ Thirty-seven test 
participants, aged 25 to 60 years, were comprised of twelve drivers 
of RV-equipped vehicles, thirteen drivers of vehicles equipped with 
an RV system and a rear parking sensor system, and twelve drivers of 
vehicles with no backing aid system. All three system conditions 
were presented using original equipment configurations of the 2007 
Honda Odyssey minivan. All participants had driven and owned a 2007 
Honda Odyssey minivan as their primary vehicle for at least 6 
months. Participants were not aware that the focus of the study was 
on their behavior and performance during backing maneuvers.
---------------------------------------------------------------------------

    \119\ 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.
---------------------------------------------------------------------------

    Participants visited a test lab to have unobtrusive video and 
other data recording equipment installed in their personal vehicles, 
and for a brief test drive. Participants then drove their vehicles 
for a period of 4 weeks in their normal daily activities while 
backing maneuvers were recorded. At the end of 4 weeks, participants 
returned to the research lab to have the recording equipment 
removed. Then, participants took a second test drive, identical to 
the first, except that when backing out of the garage bay, an 
unexpected 36-inch-tall obstacle consisting of a two-dimensional 
photograph of a child appeared behind the vehicle.

Appendix C--Details Regarding Development of a Possible Countermeasure 
Application Threshold Based on Rear Blind Zone Area

    To begin to investigate what this threshold value might be, 
NHTSA plotted the average backing and backover rates versus the 
direct-view rear blind zone areas for 28 vehicles, as shown in 
Figure C-1. Several options for setting a threshold were examined. 
One option could be to choose the natural break point on the plotted 
curve at which the slope dramatically increases for crash rate as a 
function of direct-view rear blind zone area. This option results in 
vehicles with the poorest rear visibilities that contribute 
disproportionately to backover crashes being affected. One 
observation with this option is that the worst offenders for rear 
visibility would be captured, but a large percentage of overall 
backover crashes would not be addressed, such as those involving 
small pickups.
[GRAPHIC] [TIFF OMITTED] TP04MR09.014

Figure C-1. Backing and Backover Crash Rates as a Function of Rear 
Blind Zone AreaAppendix D--Results for Analysis of Correlation Between 
Rear Blind Zone Area Measurement Field Size and Backing Crashes

    To support the determination of the dimensions of the rear 
visibility measurement field, NHTSA's measured rear blind zone area 
data for a variety of vehicles were compared with backing crashes 
for those vehicles. Data analysis was performed to assess the 
correlation between vehicles' rear blind zone areas measured using a 
50th percentile male driver and backing crash data for 21 
vehicles.\120\ Complete results of this analysis for a portion of 
the field sizes assessed are summarized in Table D-1.
---------------------------------------------------------------------------

    \120\ Mazzae, E.N., Light Vehicle Rear Visibility Assessment, 
DOT HS 810 909, September 2008. NHTSA's visual target for this test 
was a traffic cone with a reflector atop; its height is 
representative of a 1-year-old child.

[[Page 9520]]

Table D-1--Correlation Between Human-Based Rear Blind Zone Area Measured
              Over Various Field Sizes and Backing Crashes
                   [Sorted by correlation coefficient]
------------------------------------------------------------------------
                                                            Probability
 Measurement field dimensions (width by     Correlation     occurred by
                 length)                    coefficient       chance
------------------------------------------------------------------------
50W x 10L...............................         0.60117          0.0039
40W x 10L...............................         0.60117          0.0039
30W x 10L...............................         0.58233          0.0056
30W x 50L...............................         0.55212          0.0095
40W x 40L...............................         0.54681          0.0103
30W x 40L...............................         0.53635          0.0122
50W x 40L...............................         0.53113          0.0132
20W x 40L*..............................         0.52621          0.0143
50W x 50L**.............................         0.52375          0.0148
20W x 50L...............................         0.52367          0.0148
40W x 30L...............................         0.52341          0.0149
50W x 60L...............................         0.51360          0.0172
30W x 30L...............................         0.51227          0.0176
60W x 50L...............................         0.51891          0.0159
50W x 30L...............................         0.50641          0.0192
60W x 60L...............................         0.50403          0.0198
40W x 20L...............................         0.48513          0.0258
20W x 30L...............................         0.48117          0.0272
50W x 20L...............................         0.47920          0.0280
70W x 70L...............................         0.47331          0.0302
70W x 80L...............................         0.45159          0.0399
70W x 90L...............................         0.43665          0.0478
20W x 20L...............................         0.39522          0.0762
10W x 40L...............................         0.35315          0.1163
10W x 10L...............................         0.27903         0.2206
------------------------------------------------------------------------
* This measurement field size was indicated by pedestrian backover crash
  risk simulation as encompassing pedestrian locations at which risk of
  a backing crash was 20 percent or higher.
** Blind zone area measured over a field this size was found by
  preliminary analysis of laser-based measurement data to be well
  correlated with backing crashes.

[FR Doc. E9-4500 Filed 2-27-09; 11:15 am]

BILLING CODE 4910-59-P