[Federal Register Volume 63, Number 149 (Tuesday, August 4, 1998)]
[Rules and Regulations]
[Pages 41451-41466]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 98-20700]


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DEPARTMENT OF TRANSPORTATION

National Highway Traffic Safety Administration

49 CFR Parts 571

[Docket No. NHTSA-98-3847]
RIN 2127-AG07


Federal Motor Vehicle Safety Standards; Head Impact Protection

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

ACTION: Final rule.

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SUMMARY: This final rule amends the upper interior impact requirements 
of Standard 201, Occupant Protection in Interior Impact, to permit, but 
not require, the installation of dynamically deploying upper interior 
head protection systems currently being developed by some vehicle 
manufacturers to provide added head protection in lateral crashes. 
Compliance with those requirements is tested at specified points called 
``target points.'' Since compliance is often not practicable at target 
points located near the places where these dynamic systems are stored 
before they are deployed, vehicles equipped with the dynamic systems 
will be allowed to meet slightly reduced requirements at those points. 
However, these vehicles will also be required to meet new requirements 
to ensure that these dynamic systems enhance safety. This final rule 
adds procedures and performance requirements for testing the deployment 
of these systems and their protective capability through a combination 
of in-vehicle tests and a full scale vehicle crash test. In a separate 
final rule being published today, the agency is establishing 
specifications and qualification requirements for a newly-developed 
anthropomorphic test dummy to be used in determining compliance with 
the dynamic crash test requirements.

DATES: Effective Date: The amendments made in this rule are effective 
September 1, 1998.
    Petition Date: Any petitions for reconsideration must be received 
by NHTSA no later than September 18, 1998.

ADDRESSES: Any petitions for reconsideration should refer to the docket 
and notice number of this notice and be submitted to: Administrator, 
National Highway Traffic Safety Administration, 400 Seventh Street, SW, 
Washington, DC 20590.

FOR FURTHER INFORMATION CONTACT: The following persons at the National 
Highway Traffic Safety Administration, 400 Seventh Street, SW, 
Washington, DC 20590:

For non-legal issues: Dr. William Fan, Office of Crashworthiness 
Standards, NPS-11, telephone (202) 366-4922, facsimile (202) 366-4329, 
electronic mail ``[email protected]''
For legal issues: Otto Matheke, Office of the Chief Counsel, NCC-20, 
telephone (202) 366-5253, facsimile (202) 366-3820, electronic mail 
``[email protected]''.

SUPPLEMENTARY INFORMATION:

Table of Contents

I.  Background
    A.  August 1995 Final Rule on Upper Interior Impact Protection
    B.  Petitions for Reconsideration
    C.  March 1996 ANPRM on Dynamically Deployed Upper Interior Head 
Protection Systems
    D.  August 1997 NPRM on Dynamically Deployed Upper Interior Head 
Protection Systems
    E.  Comments Submitted in Response to the NPRM
II.  Final Rule
    A.  Deletion of the Proposed In-vehicle Test
    B.  Vehicle-to-Pole Test
    C.  Rigid Pole
    D.  SID/HIII Dummy
    E.  Rear Seat Dummy
    F.  Impact Speed and Conditions
    G.  Target Locations
    H.  Safety Concerns
    I.  Other Issues
    J.  Dummy Seating Position
    K.  Selection of Options
    L.  Effective Date
III. Rulemaking Analyses and Notices
    A.  Executive Order 12866 (Federal Regulation) and DOT 
Regulatory Policies and Procedures
    B.  Regulatory Flexibility Act
    C.  National Environmental Policy Act
    D.  Executive Order 12612 (Federalism) and Unfunded Mandates Act
    E.  Civil Justice Reform

Regulatory Text

I. Background

A. August 1995 Final Rule on Upper Interior Impact Protection

    The August 1995 final rule issued by the National Highway Traffic 
Safety Administration (NHTSA) amended Standard 201 to require passenger 
cars, and trucks, buses, and multipurpose passenger vehicles 
(collectively, passenger cars and LTVs) with a gross vehicle weight 
rating (GVWR) of 4,536 kilograms (10,000 pounds) or less, to provide 
protection when an occupant's head strikes upper interior components, 
including pillars, side rails, headers, and the roof, during a crash. 
This final rule, which requires compliance pursuant to a phase-in 
schedule beginning on September 1, 1998, significantly expands the 
scope of Standard 201. Previously, the standard applied mainly to the 
portion of the vehicle interior in front of the front seat occupants, 
i.e., the instrument panel. The amendments added procedures and 
performance requirements for a new in-vehicle component test.

B. Petitions for Reconsideration

    The agency received nine timely petitions for reconsideration of 
the final rule. The issues raised by the petitions can be divided into 
five categories: (1) Application of the new requirements to dynamically 
deployed upper interior head protection systems, (2) influence of 
systems variables, (3) lead time and phase-in, (4) exclusion of certain 
vehicles, and (5) test procedure.
    With respect to the last four categories of issues raised by the 
petitions, NHTSA responded by issuing amendments to the August 18, 1995 
final rule in a notice dated April 8, 1997 (62 FR 16718). In the April 
8, 1997 notice, NHTSA modified the final rule to exclude certain 
vehicles from the upper interior impact requirements of Standard 201, 
allowed carry-forward credits, changed the phase-in requirements by 
providing manufacturers with the option of complying with an additional 
alternative schedule for meeting the upper interior impact requirements 
of the standard and amended other sections of the standard to address 
concerns about test procedures.
    Since the first category of issues, those relating to dynamically 
deployed upper interior head protection systems, was outside the scope 
of the rulemaking that led to the August 18, 1995 rule, the agency 
announced that it was treating the requests relating to these issues as 
petitions for rulemaking, and was granting those petitions.

C. March 1996 ANPRM on Dynamically Deployed Upper Interior Head 
Protection Systems

    On March 7, 1996, NHTSA published an advance notice of proposed 
rulemaking (ANPRM) to assist the

[[Page 41452]]

agency in evaluating the issues raised by dynamically deployed upper 
interior head protection systems (61 FR 9136). In the ANPRM, the agency 
noted that vehicles with inflatable frontal automatic protection 
systems (i.e., air bags) meeting S5.1 of Standard No. 208, ``Occupant 
Crash Protection'' need only meet the performance requirements of 
Standard 201 when impacted at a relative velocity of 19 kilometers per 
hour (km/h) (12 mph) rather than the 24 km/h (15 mph) requirement 
imposed on vehicles not meeting S5.1 of Standard 208. This exception to 
the 24 km/h (15 mph) requirement is premised on the fact that the 
padding thickness required for surfaces to meet higher impact 
requirements interferes with the deployment of airbags. NHTSA allowed 
this exception based on the agency's belief that the tests contained in 
Standard 208 for dynamic systems provided adequate assurance that these 
systems perform well enough to protect occupants in the event of a 
crash at a speed higher than 19 km/h (12 mph).
    At the time of the ANPRM, there was no comparable way of 
accommodating the dynamically deployed upper interior head impact 
systems since neither Standard 208 nor any other Standard contained 
performance requirements or test procedures for assessing the 
performance of those systems. Without such requirements or procedures, 
there was no readily available way of providing adequate assurance that 
the systems would yield sufficient safety benefits to justify reducing 
the upper interior impact requirements for vehicles with dynamically 
deployed upper interior protection systems.
    The ANPRM suggested that performance requirements and test 
procedures be developed for those systems. Given the differences in 
design and performance between two of the best known types of such 
systems, dynamically deployed padding and dynamically deployed 
inflatable devices, the agency suggested further that those two types 
of systems be subjected to different tests. In the case of dynamically 
deployed padding, the agency suggested that existing targets specified 
in the final rule protected by the dynamic system be impacted at 19 km/
h (12 mph) prior to the deployment of the padding and then be impacted 
at 32 km/h (20 mph) with the padding deployed. This test would 
accommodate the limitations of dynamic padding systems in their 
undeployed state while providing assurance that deployed padding 
provides additional protection to occupants. In the case of inflatable 
devices, the agency discussed the possibility that it might propose 
subjecting vehicles equipped with these systems to 19 km/h (12 mph) 
headform impacts at all points that would be covered by the devices 
when inflated. These tests would be conducted with the devices in their 
undeployed state. The performance of the devices as deployed would be 
tested in a side impact test into a fixed rigid pole at 30 km/h (18.6 
miles per hour) or a side impact with a moving deformable barrier at 50 
km/h (31 miles per hour). The ANPRM also requested responses to 17 
questions relating to the design, performance, evaluation and testing 
of dynamically deployed upper interior head protection systems.
    The agency received a total of ten comments on the ANPRM. Five 
automobile manufacturers (Ford, Volvo, BMW, VW, and Mercedes), one 
restraint system suppler (Autoliv), two safety organizations (Insurance 
Institute for Highway Safety (IIHS), and Advocates for Highway and Auto 
Safety (AHAS)), and one manufacturers' association (American Automobile 
Manufacturers Association (AAMA)) and a trade group (Automotive 
Occupant Restraint Council (AORC)), submitted comments in response to 
the ANPRM.

D. August 1997 NPRM on Dynamically Deployed Upper Interior Head 
Protection Systems

    NHTSA's analysis of the comments received in response to the ANPRM 
is contained in a Notice of Proposed Rulemaking (NPRM) published in the 
Federal Register on August 26, 1997. (62 FR 45202). The NPRM proposed 
adding two test procedures to Standard 201 to accommodate development 
of dynamically deployed upper interior head protection systems. Under 
the agency's proposal, manufacturers would have the option of 
demonstrating compliance with Standard 201 in accordance with the 
requirements and procedures specified in the August 1995 final rule 
tests or with one of the two new test procedures. The first option, 
referred to as Option 1, specified performing free-motion headform 
(FMH) impacts at 24 km/h (15 mph) at all test points and target angles 
specified in the August 1995 final rule. The second and third options, 
referred to as options 2 and 3, respectively, proposed employing FMH 
testing at a reduced impact speed at those points located directly over 
a stowed dynamic system and its inflation and attachment hardware. To 
ensure that these systems offer safety benefits in the deployed mode 
commensurate with the reduction in protection provided in the 
undeployed mode as a result of the lower impact speed, options 2 and 3 
required testing of the deployed system at impact speeds above 24 km/h 
(15 mph).
    As proposed in the NPRM, Option 2 would use the existing FMH to 
simulate an occupant's head striking the interior of the vehicle in a 
crash. In this test, the headform would be propelled into specified 
targets within the vehicle at differing impact speeds. For those points 
that are not directly over a dynamic system or its attachment or 
inflation hardware, the specified impact speed would be 24 km/h (15 
mph). For points directly over an undeployed dynamic system (including 
attachment points and inflation mechanisms), the headform would be 
propelled at the target at 19 km/h (12 mph) with the system in the 
undeployed mode and 29 km/h (18 mph) with the system deployed. In order 
to test the deployment of the system, the triggering mechanism would be 
tested through use of the lateral crash test contained in S6.12 of 
Standard 214. The proposal also set forth that once triggered, the 
system would have to reach full deployment in 30 milliseconds (ms) or 
less.
    The other proposed optional test procedure, Option 3, employed a 
full scale side impact at 29 km/h (18 mph) into a fixed pole. Under 
this procedure, those target points likely to be struck in a crash, 
notwithstanding the deployment of the dynamically deployed device, 
would be tested at a higher speed than target points likely to be 
shielded by the deployed device. More specifically, any test points or 
targets inside the vehicle that do not intersect with a line oriented 
along any of the approach angles described in S8.13.4 and passing 
through an undeployed dynamic system or any of its components 
(excluding trim) would be subjected to a 24 km/h (15 mph) FMH impact at 
the target angles and conditions now contained in the Standard. For 
those targets that intersect with a line oriented along any of the 
approach angles described in S8.13.4 and passing through an undeployed 
dynamic system or any of its components (excluding trim), FMH impacts 
at a speed of 19 km/h (12 mph) would be employed to test the system in 
its undeployed condition.
    The agency noted that, under Option 3, manufacturers choosing to 
employ dynamic systems whose components are not stored in roof rails or 
other areas covered by Standard 201 would be required to meet the 24 
km/h (15 mph) FMH impact test even though such a system, in its 
deployed state, may provide head protection against impact with the 
target points specified in this

[[Page 41453]]

standard. The NPRM requested comments on whether a dynamic system 
which, when deployed and observed in a side view, completely covers the 
95th percentile eyellipse as defined in SAE Recommended Practice J941--
Motor Vehicle Driver's Eye Locations (June 92), would provide 
protection against impacts with targets on the A-pillar, B-pillar and 
side rails.
    As proposed, Option 3 would test the effectiveness of the dynamic 
system in the deployed mode, in a full scale 29 km/h (18 mph) side 
impact into a 254 millimeter (10 inch) diameter fixed rigid pole. The 
point of impact would be aligned with the center of gravity of the head 
of a dummy seated in a designated front outboard seating position on 
the struck side. In this proposed test, the seat would be positioned as 
directed in S6.3 and S6.4 of Standard 214 and the dummy located as 
directed in S7 of Standard 214. However, the agency recognized that the 
use of this seating procedure might result in interference between the 
head of the test dummy and B-pillar when used in certain vehicles. 
Therefore, NHTSA proposed modifications to the seating procedure and 
asked for comments regarding seat adjustment. The NPRM also indicated 
that NHTSA was continuing to consider the use of a second dummy in the 
rear outboard seating position of the struck side.
    Option 3 specified that the vehicle would strike the rigid pole at 
an angle of 90 degrees. The agency solicited comments on whether other 
impact angles would result in a test procedure better suited for 
evaluating performance in a crash and if the use of these other angles 
would present technical challenges in testing. The proposal indicated 
that initial pole-to-vehicle contact must occur within an area bounded 
by two transverse vertical planes located 38 mm (1.5 inches) forward 
and aft of the impact reference line. The agency requested comments on 
the degree of difficulty of achieving an impact within this range.
    The agency also proposed a new test dummy for use in the Option 3 
test. This test dummy is a SID dummy modified to accept the Hybrid III 
head and neck. The proposed performance requirements for Option 3 were 
identical to those found in the first and second options; the HIC(d) 
value would not exceed 1000.
    NHTSA also solicited comments regarding potential safety concerns 
related to any possible effects of dynamically deployed upper interior 
head protection systems on out-of-position occupants.

E. Comments Submitted in Response to the NPRM

    All commenters generally supported the agency's proposal, with a 
few exceptions on some issues. The commenters consisted of seven 
automobile manufacturers (BMW, Land Rover, Volvo, Nissan, Volkswagen, 
Mercedes and Toyota), two manufacturers' associations, the American 
Automobile Manufacturers' Association (AAMA) and the Association of 
International Automobile Manufacturers (AIAM), two safety groups, the 
Insurance Institute for Highway Safety (IIHS) and Advocates for Highway 
and Auto Safety (Advocates), one supplier (Autoliv) and one trade 
group, the Automotive Occupant Restraints Council (AORC).
    BMW made several comments on target locations, rear seat 
protection, test repeatability, out-of-position occupants, and other 
subjects. BMW concurred with the proposal that those targets directly 
over the stowed dynamic system should be tested at 19 km/h (12 mph) 
with the system undeployed. However, BMW commented that the definition 
of target exclusion specified in S6.1(c) and S6.2(c) is too narrow. In 
BMW's view, a 50 mm (2 inch) transition area between the 24 km/h (15 
mph) padding and the 19 km/h (12 mph) padding is needed for design 
purposes. The company indicated that its dynamic head protection 
system, the ITS (Inflatable Tubular System) deploys mainly out of the 
roof liner joint along the side rail and not directly through the area 
that covers it. Therefore, BMW submitted that a transition zone around 
the area where the system is stowed is necessary to ensure that 
countermeasures that would otherwise be required to meet the 24 km/h 
(15 mph) FMH impact tests would not interfere with ITS deployment. BMW 
also commented that all target locations covered or protected by the 
deployed system should be tested at 19 km/h (12 mph) when the system is 
in its undeployed mode and that the SAE 95th percentile eyellipse 
should not be used as a sole criterion to determine target exemption.
    BMW enclosed a recent safety benefit study by K. Digges and 
Associates with its comments as evidence of the effectiveness of its 
system in protecting rear seat occupants. This study projected that for 
the rear seat occupants, the number of AIS 3-5 head/face injuries 
prevented by the ITS would be much larger than the baseline number of 
AIS 3-5 injuries resulting from head-to-side rail contacts. In view of 
this, BMW argued that target locations ``protected'' or ``covered'' by 
the ITS, notably the SR3 target location, should be subject to the 19 
km/h (12 mph) FMH impact, instead of a 24 km/h (15 mph) FMH impact test 
as proposed in the NPRM under Option 3. BMW also commented that there 
is no justification for the inclusion of a rear seat dummy in the pole 
impact test.
    BMW, which has used pole tests in the development of the ITS, 
concurred with the proposed specifications for the pole test outlined 
in Option 3. Based on its own test data, BMW concluded that the NPRM 
proposed test location tolerance limit of 38 mm (1.5 
inches) is reasonable. The company also noted that the ITS system is 
tailored to protect the head of an adult occupant in the front seat and 
is, therefore, relatively small and deploys with minimal energy. In 
view of this, it would not present a threat to vehicle occupants. 
Lastly, BMW recommended that the final rule be published by March 1998 
and become effective 30 days after its publication.
    Land Rover submitted comments relating to the size of its vehicles. 
The company indicated that its multipurpose passenger vehicles are all 
over the GVWR limit of 2,722 kilograms (6,000 pounds) applicable to 
LTVs under Standard 214 and therefore do not need to pass the side 
impact requirements of that standard. Land Rover submitted that it is 
not reasonable for the company to conduct a Standard 214 side impact 
test in order to certify the 30 ms full-deployment requirement 
specified in the Option 2 test. Land Rover requested that the Standard 
301 lateral moving barrier crash test be an optional test to certify 
the 30 ms full-deployment requirement, if needed.
    AAMA commented on the proposed test procedures, including Option 1, 
2, and 3 tests. In regard to Option 1 test procedures, AAMA requested 
clarification in the wording in S6.1(a). AAMA believed that it was not 
clear from the proposal whether a vehicle not equipped with a dynamic 
system or one whose system components are not stored in the A-pillar, 
side rails or areas otherwise covered by Standard 201 must comply with 
the 24 km/h (15 mph) FMH impact requirement.
    AAMA also commented on a number of issues concerning the proposed 
Option 2 test. The comments noted that AAMA member companies did not 
understand what types of dynamic systems would be tested under this 
proposed test and that to AAMA's knowledge, no system existed that 
would use the proposed Option 2 test procedure. The AAMA comments also 
took issue with the approach angles

[[Page 41454]]

proposed for this test option as, in AAMA's view, it is possible that a 
deployed system would not be interposed between the FMH and the 
existing target locations. As a result, AAMA argued that the approach 
angles proposed in the S8.13.4 are not practical for FMH impact tests 
when the dynamic system is deployed. AAMA also contended that, under 
the proposed Option 2 test, S8.13.3 indicates that initial forehead 
contact is not necessary when conducting 29 km/h (18 mph) FMH impact 
tests against a fully deployed system. AAMA questioned the intent of 
this exclusion and relevance of FMH HIC calculated from an impact in 
which forehead initial contact will most likely not occur between the 
forehead impact zone and the target circle. The organization also 
commented that the proposed target area for 19 km/h (12 mph) FMH impact 
tests was too narrow. According to AAMA, this makes the determination 
of which targets do or do not lie over the undeployed system extremely 
difficult and impractical because the system will be covered by the 
same piece of trim. Recognizing that those targets are to be protected 
by the deployed system, AAMA recommended that any target locations that 
are protected by the system in the deployed mode be qualified for 19 
km/h (12 mph) FMH impact tests. AAMA also commented that coordination 
of inflation timing with FMH impacts would be necessary, especially if 
multiple impacts are required for certification or compliance tests. In 
addition, AAMA voiced concerns that the 29 km/h (18 mph) FMH impact 
requirement proposed for the deployed mode may discourage the 
development of such systems. AAMA also commented that any specification 
of a maximum on the time needed for a system to inflate is unwarranted, 
that imposing an arbitrary time requirement is design restrictive, and 
that specifying a short inflation time would result in an aggressive 
system. AAMA commented that the inflation time should be determined 
based on the specific system/vehicle designs and that the definition of 
``full-deployment'' needs clarification.
    Several aspects of the proposed Option 3 test created concerns for 
AAMA. AAMA indicated that the full scale crash test specified in 
S6.1(c) and S6.2(c) is burdensome, redundant, and without additional 
safety benefits. AAMA also argued against use of the proposed modified 
SID dummy (SID/HIII). The AAMA comments stated that the SID/HIII has a 
biofidelity rating of 3.8, which is below the ISO recommended 
acceptable level of 4.0. According to the AAMA, the SID is insensitive 
to padding stiffness. Further AAMA said that its tests confirmed that 
EuroSID-1 was a better dummy than the SID in discriminating change in 
door padding. AAMA also believes that other dummy test devices would be 
more appropriate and more biofidelic. AAMA stated that the EuroSID-1, 
an improved EuroSID dummy, has a biofidelity rating of 4.2. Other 
biofidelity ratings cited by AAMA in arguing against use of the SID/
HIII are 5.9 for the BioSID, 4.2 for EuroSID-1, 3.8 for the SID/HIII, 
3.2 for EuroSID and 2.3 for SID. In addition to concerns about 
biofidelity, AAMA commented that for international harmonization 
purposes, the EuroSID-1 is the most appropriate dummy. While AAMA 
requested that the International Standards Organization (ISO) make 
specific modifications to the EuroSID-1 dummy, AAMA strongly urged 
NHTSA to specify the EuroSID-1, with proper modifications as suggested 
by AAMA, as an interim dummy for Standard 201. AAMA also indicated it 
had concerns regarding the 254 mm rigid pole proposed for use with the 
Option 3 test. AAMA recommended that NHTSA specify a 350 mm pole in the 
final rule instead of the NPRM proposed 254 mm pole. According to the 
AAMA, a 254 mm pole was initially considered by ISO for its own side 
impact pole test but was rejected on the basis that the 254 mm pole is 
not representative of real world obstacles that cause serious injuries. 
AAMA also stated that neck loading has not been adequately studied by 
NHTSA and recommended that the topic be entered on the agenda of the 
Motor Vehicle Safety Research Advisory Committee and the programs of 
the International Harmonization Research Agenda. In regard to potential 
injury caused by the deployment of dynamically deployed upper interior 
head protection systems, AAMA recommended that an attempt be made to 
evaluate the impairment caused by head injuries and by potential 
hearing loss. AAMA suggested that a threshold for dynamic head 
protection system deployment be established at the crossover point 
between impairment caused by head injury and that caused by hearing 
loss. Due to the lack of actual test data on injuries from system 
deployment, AAMA recommended that this topic be a candidate topic for a 
special NHTSA study.
    AIAM commented that some of its members have planned early 
introduction of dynamic systems to provide enhanced interior head 
impact protection and urged NHTSA to complete this rule as soon as 
practical, preferably no later than March 1998.
    Volvo indicated its strong support for the proposed test procedures 
and recommended that all three options be included in the final rule. 
Volvo recommended that the final rule be published as soon as possible, 
preferably no later than March 1998. Volvo indicated that it is 
planning to install an inflatable curtain (IC) system in its production 
vehicles. Based on its current knowledge, Volvo concluded that the IC 
system would not only reduce head injuries but also prevent ejections 
through side windows. Results of its out-of-position occupant tests 
indicated that injuries of a greater severity level are not likely to 
occur as a result of an occupant, child or adult, being too close to, 
or in an undesirable position relative to the system. Volvo commented 
that the 30 ms full-deployment requirement contained in the Option 2 
proposal appears appropriate. In regard to Option 3, Volvo supported 
the reduction of FMH impact speed from 24 km/h (15 mph) to 19 km/h (12 
mph) for target locations above the stowed system, with the system 
undeployed. However, Volvo commented that all target locations covered 
by the deployed system should be also tested only up to 19 km/h (12 
mph) and that the SAE 95th percentile eyellipse should not be used as a 
sole criterion to determine protection against head impacts against A/
B-pillars and side rails. Volvo also indicated that clarification is 
needed in regard to those targets contiguous to the system's mounting 
and inflation components, but which are not within the 24 km/h (15 mph) 
impact target areas. Volvo commented that due to inadequate information 
it could not see any utility in the use of a rear seat dummy in pole 
impact tests.
    Nissan offered comments on the proposed Option 2 and Option 3. 
Apparently, Nissan understood S6.1(b) `` * * * but exclusive of any 
cover or covers, * * * '' to mean that testing would take place with 
cover or covers removed and commented that testing dynamic systems with 
full components in place would be more representative. In addition, 
Nissan commented that the agency has not provided a clear justification 
for specifying the 29 km/h (18 mph) FMH impact requirement. Nissan 
questioned whether the increase in the FMH impact speed from 24 km/h 
(15 mph) to 29 km/h (18 mph) would actually result in safety benefits 
as projected by the agency. In regard to the Option 3 test procedure, 
Nissan commented that the Option 2 test is sufficient and the Option 3 
test is

[[Page 41455]]

unnecessary. Nissan also believed that the agency has not provided a 
clear cost/benefits assessment for the new pole impact test. Nissan 
commented that the SID/HIII is a dummy without proven biofidelity 
characteristics and that biofidelity of the test dummy as a whole 
system must be approved before promulgating a regulation. In addition, 
Nissan commented that the use of the SID/HIII is in conflict with 
international harmonization efforts since ISO is considering the 
EuroSID-1 as the side impact dummy on the global basis.
    IIHS supported the proposal contained in the NPRM. IIHS commented 
that two advanced side impact air bag systems (ITS and IC) might have 
to be excluded from the U.S. market in the near future if the Standard 
201 requires 24 km/h (15 mph) FMH impact tests for all vehicle upper 
interior components. In addition, IIHS commented that the proposed 29 
km/h (18 mph) pole impact test provides a reasonable demonstration of 
the effectiveness of such dynamic systems. However, IIHS commented that 
NHTSA should be more concerned about the seating height of the dummy 
test device since the baseline pole impact test is configured to ensure 
a significant head contact with the pole. Based on its test data, IIHS 
suggested that a taller dummy (SID with the Hybrid III head/neck system 
instead of SID/HIII (using a modified neck bracket)) may provide a more 
reliable test. In addition, IIHS commented that the 350 mm diameter 
pole would produce a more repeatable test.
    Advocates supported the proposed amendments while offering several 
comments regarding the factual basis for the agency's tentative 
conclusions as set forth in the NPRM. Advocates argued that the quality 
of the administrative record for the NPRM was poor and that many public 
respondents were compelled to rely on the opinion of NHTSA about the 
value of the advanced dynamic systems. Advocates also argued that the 
agency was relying on manufacturer claims about the impossibility of 
complying with FMH impact speeds higher than 19 km/h (12 mph) for 
target SR3 without interrupting smooth interior trim design. In 
Advocates' view, the alleged marketing impact of discontinuous interior 
trim surfaces is a very poor reason for NHTSA to grant an exemption 
from a prevailing safety standard that could lead to additional 
injuries, especially when many young children would be placed in the 
rear seat. Advocates indicated that by exempting SR3 from 24 km/h (15 
mph) FMH impact, NHTSA has begun to descend a slippery slope of 
exemptions. Advocates suggested that this is the second time in the 
last few years in which NHTSA has been willing to trade increases in 
certain types of injuries for a claimed greater reduction in overall 
injuries and in their severity.
    Advocates also criticized the agency's tentative conclusion that 
the effectiveness of dynamic systems justified testing the target 
points near the undeployed systems at lower impact speeds. In 
Advocates' view, NHTSA's benefit estimate is based on some hypothetical 
assumptions, including the use of unproven levels of dynamic system 
effectiveness, two different injury curves, and manufacturer generated 
sled test data. Advocates also contends that the proposals in the NPRM 
do not sufficiently address safety concerns relating to rear seat 
occupants. The organization believes that the agency has ignored the 
fact that a massive displacement of young children from the front seats 
to rear seats will occur as frontal air bags become the norm. In 
particular, Advocates cited the agency's estimate of additional loss of 
only 17 lives and 230 non-fatal injuries contingent on exemption of SR3 
from a 24 km/h (15 mph) compliance test as exceedingly 
optimistic.1
---------------------------------------------------------------------------

    \1\ Advocates evidently misread NHTSA's evaluation of additional 
deaths and injuries. The agency estimate was in fact far lower--4 
fatalities.
---------------------------------------------------------------------------

    Advocates also noted that the dynamic head protection test options 
contained in the NPRM provide no specification for sensor performance. 
It is possible, Advocates states, that the number and rate of more 
severe injuries due to a system malfunction would be considerably 
larger than NHTSA expects. In addition, Advocates also contends that it 
is inappropriate for NHTSA to argue for or rely on anti-ejection 
benefits in its benefit estimate in support of the installation of 
dynamic systems when no rollover test was conducted by NHTSA, nor by 
any manufacturers, to verify these benefits.
    Advocates made numerous comments related to the proposed pole 
impact test. Advocates commented that the rigidity of the pole is not 
specified and that the yaw, pitch and roll behavior of the vehicle is 
controlled in such a way that the proposed pole impact test would not 
be representative of the real world crash condition. To evaluate the 
effect of dynamic systems (including side thorax air bags) on out-of-
position children in rear seats, Advocates supported the use of 
instrumented dummies in this seating position to determine the extent 
to which the head of occupants of various sizes would impact target 
points lying over the stowed dynamic system. Advocates also expressed 
concerns about head pocketing and neck injury that could potentially 
occur when occupants encounter an inflated dynamic system. In addition, 
Advocates voiced concerns that the SID/HIII test dummy proposed for use 
with the pole test may not be a reliable test device.
    VW expressed concerns regarding harmonization, test procedures, and 
the effective date of the final rule. VW argued that any differences 
between NHTSA's proposed Option 3 test procedure and the ISO 
recommended pole test is contrary to international harmonization. In 
particular, VW argued that the pole used in the Option 3 test should be 
350 mm in diameter and the EuroSID-1 should be used rather than the 
SID/HIII. VW pointed out that significant changes have been made to 
EuroSID since 1990 and that the EuroSID-1 has adopted the head of the 
Hybrid III dummy. Accordingly, VW believes that the EuroSid-1 would 
meet the requirements of the Option 3 pole test. VW stated that the 
proposed definition for the 19 km/h (12 mph) impact target areas is too 
restrictive. The company believes deployment requirements would involve 
system packaging and cover design that precludes the use of the padding 
needed to meet the 24 km/h (15 mph) impact within the areas adjacent to 
the undeployed system. VW contended that the dynamic system, in its 
full-deployment mode, would continue to provide protection by 
preventing head contacts with interior structural components. 
Therefore, VW believes that those target points that are covered by the 
deployed system should be also tested at 19 km/h (12 mph) impact speed. 
In regard to the proposed 30 ms maximum time period for reaching full 
deployment, VW stated that specifying a maximum time for full 
deployment is not necessary. VW urged NHTSA to issue a final rule with 
an immediate effective date to allow manufacturers to implement 
dynamically deployed upper interior head protection systems as soon as 
possible.
    Mercedes offered comments on the proposed Option 2 and 3 test 
procedures. In regard to the Option 2 test procedure, Mercedes 
indicated that it at present is not considering its original design 
concept of a dynamic padding system and decided to adopt an inflatable 
curtain (IC) system. In Mercedes' view, none of the currently known 
dynamic systems (the ITS/IC systems) can be certified using the Option 
2 test procedure. Mercedes commented that the maximum 30 ms time for 
full-deployment may be inappropriate but is sufficient for both

[[Page 41456]]

Option 2 and Option 3 tests. In addition, Mercedes requested that NHTSA 
address the procedure for maintaining system pressure during multiple 
impacts, when using Option 2 test. Mercedes also commented that the 
definition for exempted target points should include the area about 25 
to 50 mm (1.0 inch to 2.0 inches) wide surrounding the stowed dynamic 
systems.
    Mercedes' comments indicated its agreement with the proposed Option 
3 test. Although Mercedes had no experience with pole tests other than 
the 90 degree impact using a EuroSID dummy, it supported the agency's 
concept that the 90 degree impact represents the possible worst case 
condition. Mercedes commented that target locations BP2 and BP3, being 
protected by the dynamic system in its deployed mode, should be tested 
at 19 km/h (12 mph) in its undeployed mode. Mercedes also indicated 
that the definition for exempted target points should include the area 
about 25 to 50 mm (1.0 inch to 2.0 inches) wide surrounding the stowed 
dynamic systems. In addition, Mercedes stated that the proposed SID/
HIII dummy is not used in the ISO pole test procedure. The company 
believes that use of the SID/HIII is contrary to harmonization goals 
and that other dummies, such as EuroSID-1, should be allowed as an 
optional alternative to the SID/HIII during the phase-in period.
    Autoliv, a safety equipment manufacturer and supplier, indicated 
that all three options should be maintained in the final rule. In 
addition, Autoliv offered specific comments on options 2 and 3. Autoliv 
stated that determining full-deployment is very difficult and 
manufacturers should be given an opportunity to provide clear data to 
describe that specific state. In addition, Autoliv commented that the 
29 km/h (18 mph) FMH impact speed specified in Option 2 should be 
reduced to 24 km/h (15 mph). In reference to the Option 3 proposed test 
procedure, Autoliv argued that the 19 km/h (12 mph) FMH impact tests in 
the undeployed mode should be applicable to all target points that are 
covered or protected by the deployed system. While supporting the 90 
degree pole impact using one front seat dummy, Autoliv recommended that 
the 350 mm pole be adopted for the purpose of enhancing test 
repeatability.
    Toyota also offered comments on the Option 2 and Option 3 
proposals. Toyota argued that the proposed options are excessive and 
unjustified when compared with the original 24 km/h (15 mph) FMH impact 
test. The company stated that the development of its air curtain system 
was based on 19 km/h (12 mph) FMH impact tests in its undeployed mode 
and 24 km/h (15 mph) pole impact tests using a EuroSID-1 dummy. 
However, Toyota indicated that it prefers the Option 2 test with a 24 
km/h (15 mph) speed in the full-deployment mode since the FMH test, in 
spite of its relatively high HIC results, is more repeatable than the 
pole test. Toyota also noted that for Option 2 the 30 ms full-
deployment requirement is restrictive and unnecessary. Toyota believes 
that it is more reasonable to require full-deployment prior to dummy 
head contacts with the side structure in a Standard 214 side impact 
test.
    Toyota indicated that for Option 2 compliance tests, NHTSA should 
require that the system full-deployment condition be maintained 
throughout the testing and that impact angles be the same as those used 
for testing regular padding countermeasures. Toyota commented that all 
target areas that are covered by deployed system should only be 
required to meet 19 km/h (12 mph) FMH impact tests when undeployed.
    Toyota raised several issues concerning Option 3 test. Toyota 
supported the use of the EuroSID-1 dummy and preferred the moving pole-
to-vehicle test instead of the vehicle-to-pole test. Toyota commented 
that the +/-38 mm (1.5 inches) impact location tolerance is not 
acceptable because it is larger than 10% of the pole diameter. Toyota 
argued that the 29 km/h (18 mph) pole test is not acceptable and that 
Toyota has developed its air curtain system on the basis of 24 km/h (15 
mph) pole impact tests. In addition, Toyota commented that all target 
areas that are covered or protected by deployed system are qualified 
for 19 km/h (12 mph) FMH impact test in its undeployed mode.
    AORC supported the proposed Option 2 test procedure and recommended 
that the definition of the target points directly over the stowed 
system be expanded to include any area that would be protected by the 
system in its deployed mode. AORC supported the requirement of 
conducting a Standard 214 side impact test to evaluate the full system 
deployment condition. However, AORC commented that the 30 ms 
requirement does not measure the variance of vehicle design parameters 
and is, therefore, unnecessary. In its comments directed to the Option 
3 test procedure, AORC supported the proposed test. However, AORC 
recommended the use of a 350 mm diameter pole and an existing test 
dummy with a proper biofidelity rating for the purpose of international 
harmonization. In regard to potential injuries associated with 
dynamically deployed upper interior head protection systems, AORC 
commented that sled test data, including tests on unrestrained, small 
or child seat occupant dummies, do not show increased neck loads or 
other injuries. In addition, AORC commented that NHTSA should conduct a 
benefit evaluation to determine the use of a rear seat dummy in pole 
testing.

II. Final Rule

    After review of the comments submitted in response to the NPRM and 
further consideration of test and other data, NHTSA is adopting the 
proposed amendments with some modifications. The most significant of 
these modification is the abandonment, at the present time, of the in-
vehicle test set forth as Option 2 in the NPRM. The agency has also 
concluded that certain modifications to the Option 3 proposal are 
appropriate. These modifications include an expansion of the area over 
a stowed dynamic system that is subject to testing at the reduced 19 
km/h (12 mph) FMH impact speed, modifications to the specifications for 
the rigid pole, minor changes to the specifications for vehicle test 
attitude to accommodate different vehicle propulsion systems, and a 
modification to the proposed seating procedure for the SID/HIII dummy. 
Explanation of these changes is provided below.

A. Deletion of the Proposed In-Vehicle Test

    Two commenters, Nissan and Toyota, indicated a preference for the 
Option 2 test over the Option 3 vehicle-to-pole test. Otherwise, none 
of the comments received in response to the NPRM indicated that any 
manufacturers intended to rely on the proposed test specified in Option 
2. Mercedes indicated that, at present, none of the known dynamically 
deployed systems can be certified using the Option 2 test procedure. 
AAMA also commented that it do not know of any system that would be 
tested using this optional test procedure.
    Following the publication of the August 1995 final rule, several 
manufacturers presented information to NHTSA regarding the development 
of advanced dynamically deployed systems. Ford indicated it was 
developing a new side impact air bag system for both chest and head 
protection. BMW and Volvo disclosed their development of the ITS and 
the IC, respectively. Mercedes indicated that it

[[Page 41457]]

was studying a ``dynamically deployed padding'' system. Mercedes 
described this system as special materials used for the molding and 
trim of the A- and/or B-pillars and side rails. In a side impact, those 
materials would be energized and enlarged to provide greater cushioning 
and improved head protection.
    While the Option 3 test procedure was intended to be used for 
certifying the ITS, IC and other side impact air bag systems, the 
Option 2 test procedure was conceived by the agency as potentially 
appropriate for certifying potential dynamic padding designs such as 
the system once under development by Mercedes. Mercedes is presently 
not considering the inflatable padding concept and adopted an IC 
design. However, Toyota, which is also developing an IC design, 
indicated that it preferred to test this design through use of the 
Option 2 test with an FMH impact of 24 km/h (15 mph) against a deployed 
system rather than the Option 3 vehicle to pole test. The company's 
comments indicated that it believed the Option 2 test would be more 
repeatable and realistic. Toyota did not, however, elaborate on these 
points other than to express its view that Option 2 testing would be 
representative of a variety of crash modes while the Option 3 test 
represents a single crash mode. Nissan expressed its preference to the 
Option 2 test on the basis of cost, indicating that it believed the 
Option 3 test was not needed and would be a higher cost alternative to 
Option 2. Nissan did not, however, submit any data indicating that this 
belief was based on any testing it had performed or that its preference 
for the Option 2 test was based on any system it was developing.
    NHTSA is concerned that the Option 2 test presents a number of 
technical challenges which indicate that it may not be as repeatable or 
reliable as the Option 3 test. For instance, the validity of the HIC 
transfer function specified in S7(a) is in question when it is applied 
to FMH impacts against a dynamically deployed system. In addition, 
there may be other technical problems with the test related to the 
flexibility of deployed dynamic systems and the behavior of the FMH 
when it makes contact with the system. The agency notes that it does 
not have any experience in conducting tests with the FMH against a 
deployed system and further observes that, with the exception of 
Toyota, which conducted 15 mph FMH impacts against a deployed system, 
no other manufacturers appear to have attempted such testing. This lack 
of experience and test data make it difficult or impossible for the 
agency to fully evaluate the Option 2 proposal at this time.
    NHTSA is aware that the Option 2 test has the potential to evaluate 
system performance in a greater variety of crash modes than the Option 
3 vehicle to pole test. However, the rapid development of dynamically 
deployed upper interior head protection systems necessitates immediate 
changes to Standard 201 to allow manufacturers the opportunity to place 
these systems in production vehicles. The agency is confident that the 
Option 3 test provides a valid means for assessing the performance 
characteristics of dynamic head protection devices. Unfortunately, the 
absence of data and experience in performing the proposed Option 2 test 
does not allow NHTSA to have the same degree of confidence in the 
Option 2 test. The agency may reconsider use of the Option 2 test in 
the future, but has concluded that Option 2 must be deleted from this 
final rule.
    The agency's decision to delete the Option 2 proposal from the 
final rule renders further discussion of the comments relating to 
Option 2 unnecessary. However, several issues which are germane to both 
Option 2 and Option 3 are addressed in the discussion below relating to 
Option 3.

B. Vehicle-to-Pole Test

    The agency is adopting the Option 3 Test Procedure with one 
modification. This modification, which expands the area over an 
undeployed dynamic system which is subject to the 19 km/h (12 mph) FMH 
impact test, does not substantially modify the Option 3 proposal set 
forth in the NPRM. The agency notes that BMW, Volvo, IIHS, and AORC 
substantially supported the Option 3 test procedure as outlined in the 
NPRM. IIHS commented that the NPRM proposed pole test provided a good 
demonstration of the additional head protection offered by systems such 
as the ITS and IC. Three commenters, Toyota, Nissan and AAMA, do not 
support the full scale pole impact test on the basis that the Option 3 
test is redundant, burdensome and provides no additional safety 
benefits.
    NHTSA observes that the 29 km/h (18 mph) vehicle-to-pole test was 
suggested by BMW and supported by several European manufacturers who 
have already installed or are planning to install dynamically deployed 
upper interior head protection systems in their production vehicles. 
The agency is employing this optional test procedure to accommodate 
dynamic systems, which testing has shown to have substantial safety 
benefits.
    Toyota, which has been using a 24 km/h (15 mph) pole test itself in 
the development of a dynamic system, appears to be objecting to the 29 
km/h (18 mph) impact speed of the Standard 201 pole test. As discussed 
elsewhere in this notice, NHTSA believes that the 29 km/h (18 mph) 
impact speed is necessary to provide assurance that dynamic systems 
will provide safety benefits. Nissan's principal objection to the 
Option 3 pole test was based on its view that the test was redundant 
when the proposed Option 2 test was also available. However, now that 
the Option 2 test has been withdrawn from consideration, Nissan's 
objection is not valid. AAMA's objection that the Option 3 test was 
unduly burdensome was not supported by any further explanation. Several 
commenters raised various questions concerning the test procedure. 
These questions included ones relating to the size and configuration of 
the rigid pole, the suitability of the SID/HIII dummy, inclusion of a 
dummy in the rear seat during testing, impact speeds, impact 
tolerances, out of position occupants, target points subject to reduced 
FMH impact speeds, benefit analyses, and the effective date of the 
final rule.

C. Rigid Pole

    In regard to the size of the rigid pole struck in the Option 3 
test, IIHS, VW, Nissan, Autoliv and AORC commented that the pole should 
be 350 mm in diameter, rather than the 254 mm pole proposed in the 
NPRM. IIHS also commented that the 350 mm pole impact test is less 
severe, but has higher test repeatability, than the 254 mm pole test. 
AAMA commented that the 254 mm pole was initially considered, but was 
rejected by ISO working groups because the 254 mm pole was not 
representative of real world obstacles that would produce serious 
injuries. In addition, AAMA pointed out that two recent ISO draft 
technical reports (issued in May 1997) concerning the performance of 
side air bags recommended the use of 350 mm pole. These 6 commenters 
support the use of the ISO 350 mm pole for international harmonization 
purposes.
    NHTSA began research to develop a test procedure for certifying the 
advanced dynamic systems after the agency received information on the 
advanced dynamically deployed upper interior head protection systems 
from Ford, BMW, Mercedes and Volvo in 1995. The agency carefully 
examined the draft ISO Technical Report ``Road Vehicles--Test 
Procedures for Evaluating Various Occupant-Interactions with Deploying 
Side Impact

[[Page 41458]]

Air Bags'' (ISO/TC 22/SC 10/WG 3 N100; Oct. 19, 1995) and attempted to 
replicate, to the greatest possible extent, the test procedures 
outlined in the draft report. Section 3.5 of the ISO report provided 
the following specifications for the pole:

    A vertically-oriented circular, rigid pole-like metal structure, 
beginning no more than 100 mm above the ground, and extending above 
the roof of the impacting vehicle. The pole should be 200-380 mm in 
diameter and set off from any vertical mounting surface by at least 
1500 mm.

NHTSA decided to adopt a 254 mm pole for the Option 3 test because it 
is within the ISO recommended pole diameter range, results in a more 
severe impact, and because the 254 mm pole is more representative of 
impacts occurring in the United States. The agency also notes that the 
Federal Highway Administration (FHWA) of the Department of 
Transportation has accumulated extensive experience on side impact 
tests against a 254 mm pole. FHWA's test experience enabled NHTSA to 
develop a practical test procedure in a relatively short period of 
time.
    In 1989, FHWA published a technical paper (SAE Paper 890377 ``A 
Summary of Recent Side Impact Research Conducted by the Federal Highway 
Administration'') on the subject. The paper indicated that each year 
approximately 12,000 fatalities occurred in single vehicle crashes 
against fixed objects and about 2,700 of the 12,000 fatalities occurred 
in side crashes. About 60 percent of the 2,700 fatalities in single 
vehicle side crashes were associated with impacts against trees, 
utility poles, and other poles. FHWA concluded that the pole diameter 
at the window sill level for most poles is approximately 254 mm. NHTSA 
conducted a review of National Automotive Sampling System (NASS) data 
in an effort to determine if the 254 mm diameter object is 
representative of trees struck as well as poles. Unfortunately, the 
available NASS data do not allow the agency to determine if the 254 mm 
pole is representative of trees struck in crashes in the United States. 
Nonetheless, the 254 mm diameter pole does represent an important 
injury source responsible for a significant percentage of fatalities 
occurring in single vehicle side crashes against fixed objects in the 
United States. The ISO decision to reject the 254 mm pole was based on 
French crash data indicating that a larger pole more appropriately 
reproduced crashes in France. However, the French data also show that 
pole impacts are an important source of occupant fatalities/injuries in 
side crashes with fixed objects.
    After review of the available data, NHTSA does not agree with 
AAMA's contention that the 254 mm diameter pole is not representative 
of real world obstacles producing severe head injuries. The agency 
notes that FHWA data, summarized and presented in SAE paper 890377, 
show that side impacts to poles constitute a serious highway safety 
problem in the United States. It should also be observed that the AAMA 
comments are based on the French crash data. However, the French data 
shows that the poles of 150-300 mm in diameter are an important injury 
source in side crashes with fixed objects.2
---------------------------------------------------------------------------

    \2\ French data show that the distribution of the tree/pole 
fatal impacts (excluding impacts with other fixed objects) is 18 
percent to trees with a diameter of 300-400 mm, 24 percent to poles 
(this may include trees since there is no mention of trees with a 
diameter of less than 300 mm in the French crash data) with a 
diameter of 150-300 mm. The French data seem to support using a 254 
mm pole instead of a 350 mm pole because it shows a larger percent 
of fatalities occurring in impacts against 150-300 mm poles than in 
impacts against 300-400 mm diameter trees.
---------------------------------------------------------------------------

    NHTSA has determined that a 254 mm pole, a size within the range 
recommended in the 1995 draft ISO technical report, simulates a real 
world crash condition corresponding to a known highway safety problem 
in the United States. As the 254 mm pole is representative of 
conditions in the U.S., the agency has performed testing and research 
using this pole size in developing the Option 3 test procedure.
    The 254 mm pole used in this test was first described in the 
agency's March 7, 1996 ANPRM describing proposals for testing dynamic 
systems. NHTSA did not receive any comments regarding pole size in 
response to the ANPRM. The agency was aware, however, that some 
manufacturers were using the 254 mm pole for vehicle-to-pole impact 
tests while the agency pursued its own testing to validate the proposed 
test procedure. When the two ISO draft technical reports that rejected 
the 254 mm pole were issued in May 1997, the agency had already taken a 
considerable number of steps toward finalizing its test procedure. It 
should also be noted that those manufacturers who currently plan to 
install advanced dynamic systems in their vehicles do not oppose the 
use of 254 mm pole. In addition, adoption of the 350 mm pole size, 
which has not been finally adopted by the ISO working groups, would 
result in a significant delay of this rulemaking, since additional 
testing would be necessary.
    NHTSA has concluded that testing with the 254 mm diameter pole is 
practical, that this test is repeatable, and that the test is a valid 
means for assessing the performance of dynamic systems. NHTSA is, 
however, modifying the specifications for the rigid pole. The diameter 
of the pole remains at 254 mm, but NHTSA is adding a tolerance of 
3 mm to the pole diameter specification. As proposed in the 
NPRM, S8.25 specified that the rigid pole must begin at a point not 
more than 102 mm (4 inches) off the ground and extend to a minimum 
height of 80 inches. As certain devices used for transporting a vehicle 
into the pole during a test may require that the vehicle be raised off 
of the ground, NHTSA has concluded that the dimensions proposed in the 
NPRM might result in a pole configuration where the pole does not 
extend above the roof of the vehicle or at its lowest point could 
interfere with carriage of the test vehicle into the pole. Accordingly, 
the final rule has modified S8.25 to specify that the lowest point of 
the pole be not more than 102 mm (4 inches) above the lowest point of 
the tires of the test vehicle and that the highest point of the pole 
extend above the highest point of the roof of the test vehicle.
    In addition, the agency notes that, as proposed, S8.25 specified 
that the test vehicle not strike any portion of the pole mount at any 
time during the test. After conducting several tests, NHTSA has 
concluded that this specification is unrealistic and has modified it to 
state that the test vehicle may not contact any part of the pole 
support structure within 100 milliseconds of the initial vehicle to 
pole contact.

D. SID/HIII Dummy

    Although the agency published a separate Notice of Proposed 
Rulemaking (NPRM) on December 8, 1997 (62 FR 64546) outlining proposed 
specification for the SID/HIII dummy, it also addressed the SID/HIII in 
the NPRM preceding this final rule. As the NPRM proposing the SID/HIII 
was not issued simultaneously with the proposed changes to Standard 
201, some commenters offered their views regarding the SID/HIII in 
response to August 26, 1997 Standard 201 NPRM. Mercedes and VW 
commented that significant changes to EuroSID have been made since 1990 
and that the ISO pole test procedure specifies the new EuroSID-1 dummy 
with the Hybrid III head. These commenters recommended that NHTSA adopt 
the EuroSID-1 for international harmonization purposes. Nissan 
commented that the SID/HIII dummy does not have a proven biofidelity 
rating and is in conflict with harmonization. Toyota also supported the 
use of the EuroSID-1. AORC

[[Page 41459]]

commented that the dummy test device should have a proper biofidelity 
rating and be capable of harmonization with the ISO standard. The 
organization also stated that an existing dummy should be specified as 
an option pending further evaluation of the SID/HIII dummy. AAMA argued 
against use of the SID/HIII on the basis that the proposed dummy has a 
much lower biofidelity rating than the EuroSID-1 and the BioSID and 
that the EuroSID-1 is better in discriminating changes in door padding. 
Therefore, AAMA recommended that NHTSA adopt a modified EuroSID-1 as an 
interim dummy instead of the SID/HIII. IIHS raised the issue concerning 
the seating height of the dummy, stating that a taller dummy seating 
height provides for a better test configuration. Advocates commented 
that it is waiting to see if the SID/HIII is a reliable dummy test 
device.
    The commenters raise two significant issues. The first is that the 
SID/HIII has a lower biofidelity rating than the BioSID and the 
EuroSID-1. Secondly, the use of any dummy other than the EuroSID-1 
conflicts with international harmonization.
    With respect to the dummy biofidelity, AAMA commented that the ISO 
biofidelity ratings (5.9, 4.2 and 3.8 for the BioSID, EuroSID-1 and 
SID/HIII dummies, respectively) demonstrate that the SID/HIII is not a 
proper choice for a pole impact test. The agency does not agree that 
the SID/HIII is not a proper choice for head-to-pole impact tests 
because the SID/HIII has a head and neck system similar to the BioSID. 
The biofidelity ratings cited by AAMA are ``overall'' ratings, not just 
for the head/neck complex. However, the critical component for the 
purposes of the Option 3 test is the head and neck. AAMA also commented 
that the NHTSA's biofidelity rating for the SID/HIII is high because 
the agency did not combine the neck and shoulder components into an 
integrated assembly for proper rating. Since the SID/HIII does not have 
a metal skeletal shoulder structure and is not sensitive to door 
padding stiffness, the ISO working group gave the SID shoulder assembly 
a ``zero'' rating. NHTSA has concluded that this rating is not relevant 
to use of the SID torso in the SID/HIII dummy proposed for the Option 3 
test. The agency observes that no relevant data on pole (or high, rigid 
wall) impact tests were considered in the development of the ISO 
biofidelity rating for side impact dummies. In high speed lateral 
impacts against high, rigid walls, the shoulder of human cadaver test 
subjects collapse in a movement towards the spine. In a rigid pole 
impact (similar to a high, rigid wall impact), the dummy shoulder 
component should, like the shoulder of a human cadaver, collapse 
without shielding the head and neck from impacts with intruding objects 
such as a rigid pole. The agency notes that the current biofidelity 
rating scheme used by the ISO working group does not recognize this 
important factor. Further, NHTSA believes that existing data 
demonstrate that the SID shoulder, which collapses as a human cadaver 
shoulder does in side impact tests, should receive at least a 2.5-3.0 
rating for pole impacts. With this 2.5-3.0 rating, the SID/HIII 
receives a 4.2 overall biofidelity rating. This rating is above the ISO 
recommended 4.0 acceptable level.
    The BioSID shoulder is rigidly attached to a stiff clavicle 
component and the EuroSID-1 shoulder is a rigid component with limited 
forward rotation capability upon contact. The agency believes that the 
shoulders of those two dummies would not collapse and move out of the 
way under various lateral impact conditions. In contrast, the SID/HIII 
shoulder is made of foam materials and will collapse upon an impact. 
The ISO working group does not acknowledge that this special shoulder 
design makes the SID/HIII a desirable dummy test device for the 90 
degree pole impact test. The agency notes that the BioSID that has the 
highest biofidelity rating among all five existing side impact dummies 
(new ratings from the ISO working group; BioSID=5.9, EuroSID-1=4.2, 
SID/HIII=3.8, EuroSID=3.2, and SID=2.3.), but that BioSID proved to be 
unsuitable in one of the 29km/h (18 mph), 90 degree pole impact tests 
conducted at IIHS in accordance with the NPRM proposed test procedures. 
In a test of a 1997 BMW 528i vehicle, the BioSID shoulder joint 
contacted the intruding side structure and failed to collapse. This 
failure to collapse, which is inconsistent with human cadaver tests, 
prevented head-to-pole contact. This unhuman-like response of the 
BioSID shoulder demonstrates a possible deficiency in the ISO 
biofidelity rating scheme. In a subsequent IIHS pole test using a SID 
with the Hybrid III head/neck assembly, the shoulder collapsed in a 
representative fashion and the test was successful. In its comments, 
IIHS pointed out that the vehicle-to-pole impact test is highly 
repeatable when the SID with a Hybrid III head/neck assembly is used.
    NHTSA does not agree with those commenters urging use of the 
EuroSID-1 dummy for the Option 3 test. It is anticipated that the 
kinematics of the EuroSID-1 shoulder, if it does not prevent head-to-
pole contact, may induce fore and aft head motion prior to head impact. 
NHTSA believes that such fore and aft head motion of the EuroSID-1 
would be difficult to control. A 1988 report regarding the EuroSID 
(Proceedings of the Seminar held in Brussels, Dec. 11, 1988) indicated 
that the EuroSID shoulder rotation mechanism produces a force ranging 
from 2.0 to 3.4 kN (450 to 760 pounds) during a series of 4.3 m/s (9.6 
mph) impacts using a 23.4 kg (51.5 pounds) impactor. The peak force 
occurs within 10 to 15 ms upon impact. NHTSA does not know if the 
performance of the EuroSID-1 is improved in this area and those urging 
use of the EuroSID-1 have not supplied any data on this point. The 
agency suspects that the head impact location tolerance for pole impact 
tests may be very difficult to define if the EuroSID-1 is used as the 
dummy test device. The EuroSID-1 has also not been generally accepted 
by the testing community as a valid test device. Modifications to this 
dummy are ongoing and an intensive evaluation program of the EuroSID-1 
is expected to begin in 1999. NHTSA cannot seriously consider the 
EuroSID-1 as a test device, particularly for the 90 degree pole tests, 
until this device becomes generally accepted and sufficient data become 
available to assess its performance.
    NHTSA, as well as IIHS and several interested manufacturers, have 
conducted vehicle-to-pole impact tests using the SID/HIII dummy (or 
SID+Hybrid III head/neck/neck bracket) for the purposes of evaluating 
proposed Option 3 test procedure. The agency has concluded that the 
SID/HIII is an appropriate dummy test device for this test. The BioSID 
is not acceptable and the EuroSID-1 is not yet ready. Given the fact 
that NHTSA must promulgate a final rule to accommodate dynamically 
deployed upper interior head protection systems and that the SID/HIII 
offers adequate performance using existing and proven components, the 
agency concludes that the SID/HIII is the best test device available 
for the Option 3 test.
    With respect to the international dummy harmonization, the agency 
supports the goal of developing a global dummy test device. The agency 
will evaluate the global dummy test device after its completion and 
then decide what to do. At present, the agency has decided to adopt the 
SID/HIII dummy for head-to-pole impact evaluation.
    In reference to the IIHS's concern on dummy seating height, the 
agency concludes that current test data show that the seating height of 
the SID/HIII

[[Page 41460]]

dummy is sufficient. With respect to the Advocates' concern on dummy 
reliability, the agency concludes that the SID/HIII, which is 
constructed from known components with sufficient durability, is a 
reliable dummy test device for the 90 degree pole test.

E. Rear Seat Dummy

    A number of commenters discussed the use of a rear seat occupant 
dummy in the Option 3 test. AORC, Volvo and BMW each indicated that 
placing a dummy in the rear seat would not produce meaningful data and 
would add cost and complexity to the test procedure. After 
consideration of these comments and after performing several Option 3 
vehicle to pole tests, NHTSA has concluded that placing a dummy in the 
rear seat of the struck side in a vehicle to pole test is unnecessary. 
Both the pole test data and a recent safety benefit analysis (Benefits 
Analysis of the Inflatable Tubular Structure (ITS), August 19, 1997) 
submitted by BMW indicate that a rear seat dummy is not needed. NHTSA 
conducted five 29 km/h (18 mph) pole impact tests using 1995 Hondas to 
verify the proposed dummy seating procedure and other aspects of the 
proposed Option 3 test. In the first two tests, the dummy head impacted 
the B-pillar without really contacting the pole. The HIC readings for 
those two tests were in the 500-600 range, far below the 1,000 limit. 
These results indicate that in a 29 km/h (18 mph) side impact with a 
254 mm pole, HIC scores near or above 1000 are not likely to be 
encountered unless the dummy's head makes direct contact with the pole 
itself. The agency believes that the head of a rear seat dummy will not 
contact the intruding pole aimed at the front occupant's head and is 
likely to contact some components more forgiving than the B-pillar, 
resulting in a low HIC reading. A recent safety benefit analysis 
submitted by BMW estimates that, for rear seat occupants, the overall 
number of AIS 3-5 injuries saved by its ITS system would be larger than 
the baseline number of AIS 3-5 injuries from side rail contacts. 
Inflatable curtain systems now under development protect both the front 
seat and the rear seat occupants. In view of these factors, it appears 
that dynamic systems offer considerable safety benefits for rear seat 
occupants and the addition of a test dummy to the rear seat in the 
Option 3 test is unwarranted.

F. Impact Speed and Conditions

    Toyota commented that the pole impact speed should be 24 km/h (15 
mph) instead of 29 km/h (18 mph) and the proposed impact tolerance 
limit of 38 mm (1.5 inches) that is more than 
10 percent of the pole diameter is not acceptable. In contrast, BMW 
commented that the proposed impact location tolerance limit is 
reasonable. In its comments, Advocates indicated that it supports the 
proposed pole test procedure because it represents the possible worst-
case crash condition, although it does not conform with real crashes 
given that the roll, yaw and pitch angles are controlled in the test. 
Further, Advocates expressed concerns that many manufacturers will 
avoid the pole test since the agency proposed two alternative test 
procedures (e.g., Options 2 and 3). Volvo commented that the pitch 
angle does not seem to have any effect, but the yaw angle appears to be 
a sensitive factor, to the proposed 90 degree pole impact test.
    The agency has concluded that the 29 km/h (18 mph) impact speed 
specified for Option 3 is appropriate. Discussion of this issue in the 
NPRM indicated that this speed was selected in an attempt to ensure 
that any safety losses incurred by allowing manufacturers to test 
certain target points at 19 km/h (12 mph) would be offset by a safety 
benefit of similar or greater magnitude. Benefit analyses performed by 
the agency and by others indicate that the 29 km/h impact speed 
specified for Option 3 is appropriate to ensure a net increase in 
safety.
    In regard to minimum tolerances for pole contact with the test 
vehicle, the agency does not agree with Toyota's contention that the 
38 mm (1.5 inches) tolerance limit is not 
acceptable because it is greater than 10 percent of the pole diameter. 
The tolerance is measured from the longitudinal centerline of the pole 
to ensure a square head impact and is based on the head contacting the 
pole within a segment that is relatively perpendicular to the head 
velocity. In selecting this tolerance, the agency does not believe that 
the pole diameter is particularly relevant. Testing has revealed, 
however, that the tolerance is necessary to assure practicability. 
Accordingly, the agency has concluded that it will retain the impact 
tolerance proposed in the NPRM for the final rule.
    NHTSA is also incorporating the requirement contained in the Option 
3 proposal that the test vehicle strike the pole at an angle of 90 
degrees with an impact tolerance of 3 degrees. The agency 
has concluded that this specification is sufficient and that roll, yaw 
and pitch angles do not need be specified. NHTSA agrees with Volvo's 
comment that yaw angle may alter the impact location. However, the 
purpose of controlling those angles in a pole impact test is to 
determine a practical impact location tolerance level. The pole impact 
tests conducted by the agency and other interested manufacturers 
indicate that the impact location tolerance proposed in the NPRM is 
reasonable. In view of this, NHTSA has concluded that it is not 
necessary to specify roll, pitch and yaw angles in the final rule and 
that the NPRM proposed impact angle, with a tolerance limit of +3 
degrees, will be incorporated in the final rule.

G. Target Locations

    A number of commenters offered their views on target locations for 
the 19 km/h (12 mph) FMH impact test in Option 3. Mercedes, Volvo, VW, 
BMW, Toyota, Autoliv, and AAMA stated that the 19 km/h (12 mph) impact 
requirements for target locations over a stowed dynamic system is 
desirable and that target locations protected by the deployed dynamic 
system should also be tested at 19 km/h (12 mph) impact speed. In 
addition, Mercedes, VW, BMW and AAMA commented that the proposed 19 km/
h (12 mph) target impact area is too narrow since the required system 
deployment would involve system packaging and cover designs. These 
commenters argued that the definition of 19 km/h (12 mph) targets 
should include the peripheral area surrounding the dynamic system in 
its stowed position. Mercedes commented specifically that this 
peripheral area include a 25 to 50 mm (1.0 to 2.0 inch) surrounding 
area. However, BMW suggested a 50 mm (2.0 inch) surrounding area. Both 
Volvo and BMW commented that the 95th percentile SAE eyellipse can not 
be the sole criterion to determine protection on head impacts against 
the A/B-pillars and side rails. BMW also commented that the range of 
occupant heads extends well above and behind the SAE eyellipse. Some 
manufacturers and AAMA indicated that target exemptions should be 
determined using the potential head protection capability of the 
deployed system.
    The foregoing comments raise three issues: first, whether target 
locations covered or protected by the deployed system should be tested 
at 19 km/h (12 mph); second, whether the 19 km/h (12 mph) target 
location area should be expanded to include the peripheral area 
surrounding the stowed system; and third, whether the SAE 95th 
percentile eyellipse is a suitable measure for determining head 
protection. With respect to targets ``protected'' by a dynamic system, 
the agency proposed that all target locations that are located over a 
stowed dynamic system, including mounting and inflation

[[Page 41461]]

components, but exclusive of cover and covers, are excluded from the 24 
km/h (15 mph) FMH impact requirements. However, those target locations 
must comply with the 19 km/h (12 mph) FMH impact requirements. 
Recognizing that a deployed system would prevent head contacts with 
some additional target locations other than those covered by the stowed 
system, the agency solicited comments on how to define the exclusion 
coverage. The commenters indicated that all target locations covered by 
the deployed system should be excluded from 24 km/h (15 mph) FMH impact 
tests. NHTSA notes that this definition is very subjective and would 
certainly create problems in testing and enforcement. However, the 
agency has found a more comprehensive definition of target points 
``covered'' or ``protected'' by a dynamic system to be elusive. A point 
that may be protected from one class of occupant may not be protected 
from another. Similarly, the points protected and the extent of that 
protection may vary with system design. In the interests of expediting 
issuance of the final rule, the agency has concluded that the 
definition of target points subject to the reduced 19 km/h (12 mph) FMH 
impact requirements is the best definition available at this time and 
that no additional target locations should be excluded from 24 km/h (15 
mph) FMH impact tests.
    A number of manufacturers asked that the definition of the target 
locations subject to the 19 km/h (12 mph) FMH impact requirements be 
expanded to include an area 25 to 50 mm (1.0 to 2.0 inch) around the 
periphery of the undeployed system and its components. These commenters 
argued that dynamic systems do not simply deploy through the cover 
directly over the stowed system. Moreover, the manufacturers indicated 
that additional space is needed to provide the necessary transition 
between the ``24 km/h (15 mph)'' padding and the ``19 km/h (12 mph)'' 
padding.
    NHTSA concludes that this is a valid concern. An inflatable system 
may not deploy directly through the area over where it is stowed. These 
systems may go through the surrounding area. In order to allow system 
deployment with minimum interference, it may be important to provide a 
transition area where padding is reduced. BMW indicated that target SR2 
is slightly off the stowed ITS position and must be tested, according 
to the current proposal, at 24 km/h (15 mph) impact speed. Since the 
roof liner/trim is a continuous piece, the whole roof liner/trim must 
be redesigned to comply with the 24 km/h (15 mph) FMH impact 
requirements. BMW contends that this defeats the original purpose of 
exempting target locations from 24 km/h (15 mph) tests to allow 
manufacturers to install enhanced head protection systems, such as ITS 
and IC, in their production vehicles. The company suggested that an 
additional 50 mm (2.0 inch) area that surrounds the periphery of the 
stowed system be included in the definition of the exempted target 
locations. The agency does not agree with BMW's contention that 
compliance with the 24 km/h (15 mph) impact requirement in areas near a 
stowed system is difficult or impossible if the two areas share common 
trim, but it does acknowledge that the requirements of different 
dynamic systems may require that an area around the outside of the 
stowed system must be subject to the 19 km/h (12 mph) FMH impact 
requirement to allow a variety of systems an opportunity to deploy 
upward or downward as well as directly through the trim covering the 
device. NHTSA observes that the agency's benefit estimate assumed that 
SR1, SR2 and SR3 targets would be exempt from 24 km/h (15 mph) 
compliance tests. Accordingly, this modification, which may exclude 
these points depending on system design, would not alter the agency's 
prior safety benefit estimate. The final rule modifies the Option 3 
proposal to add areas around the periphery of an undeployed system to 
those target points subject to the 19 km/h (12 mph) FMH impact 
requirements.
    Commenters also offered their views regarding the use of the SAE 
95th percentile eyellipse to define those targets that would be subject 
to FMH testing at reduced impact speeds. NHTSA agrees with Volvo and 
BMW that the eyellipse should not be used as a sole criterion to 
determine target location exemption. The agency entertained the 
possibility of using the eyellipse to accommodate side air bag systems 
installed inside the seat bolster or outer edge of the seat back. 
However, AAMA did not comment on this specific item but suggested, as 
did some foreign manufacturers, that any target locations where head 
contacts are protected by the deployed system should be excluded from 
the 24 km/h (15 mph) FMH impact test. As noted above, NHTSA believes 
this suggestion to be impractical. Since the agency's existing 
definition allows the installation of dynamic systems, there is 
insufficient justification for excluding additional target locations. 
NHTSA concludes that the SAE 95th percentile eyellipse is, by itself, 
not an appropriate mechanism for determining targets subject to lower 
impact speeds.

H. Safety Concerns

    A number of commenters offered their views on safety concerns 
associated with the deployment of dynamically deployed upper interior 
head protection systems. Toyota, offering its view that the 29 km/h (18 
mph) impact proposed for testing deployed systems was excessive, argued 
that the 29 km/h (18 mph) impact requirement would result in 
dangerously aggressive dynamic systems. Advocates commented that as 
frontal air bag concerns displace children from front seat to rear 
seats, reducing impact requirements for any rear seat area target 
points should be regarded with suspicion. In addition, Advocates 
commented that by excluding the SR3 target point without adequate 
justification, NHTSA is deferring to the wishes of manufacturers 
without any justification. Volvo commented that their out-of-position 
occupant tests indicate that injuries of a greater severity level are 
not likely to occur as a result of an occupant, child or adult, being 
too close to, or in an undesirable position relative to, the system. 
BMW commented that the ITS system, tailored to protect the head of an 
adult occupant, is very small and deploys with a minimum amount of 
energy. According to BMW, the ITS does not present an ``aggressive'' 
threat to vehicle occupants. In its comments, AORC indicated that sled 
tests, including tests on unrestrained, small or child seat dummies, do 
not show increased neck loads or other injuries resulting from the 
deployment of dynamic systems.
    While NHTSA agrees with Advocates that many young children will be 
seated in rear seats instead of front seats, the agency does not agree 
that this phenomenon, in conjunction with the exclusion of SR3 from the 
24 km/h (15 mph) compliance test, creates a safety concern. In a non-
rollover crash, the head of a child in the rear seat is not likely to 
be in a position to contact SR3. In addition, NHTSA's analysis of 1992-
1996 NASS, rollover/non-ejection data indicates that the head/face of 
719 second-seat occupants, including 154 children of 10 years of age or 
younger, contacted the rear side rails resulting in five AIS-1 or 
greater head/face injuries, including one AIS-5 or greater injury and 
that no child of 10 years of age or younger sustained any head/face 
injury. It appears that the Advocates' comment that excluding SR3 will 
result in greater injuries to children is not borne out by data on real 
world crashes.

[[Page 41462]]

    With respect to out-of-position child problems, the agency does not 
have its own studies and relies, at present, on the manufacturers' test 
data to evaluate the problem. Based on the comments from Volvo, BMW and 
AORC, it appears that out-of-position occupants, including children and 
adults, would not be placed at risk by dynamically deployed upper 
interior head protection systems. The agency notes that side air bags 
and dynamically deployed upper interior head protection systems are 
relatively small and less aggressive compared to front passenger air 
bags, and that the design of these systems has benefitted from the 
experience gained from frontal air bag systems. However, the agency 
will continue to monitor and test dynamically deployed upper interior 
head protection systems as they become available.
    NHTSA has also concluded that dynamically deployed upper interior 
head protection systems would not present a risk of additional neck 
injuries. The results of the BMW 528i car-to-pole tests conducted at 
IIHS indicated that dummy neck loads in the test with the ITS system 
are either lower than, or at least remain approximately the same as 
those in the baseline test without the ITS system. In view of this, 
NHTSA concludes that despite the concerns voiced by Advocates, the ITS 
system or the IC system is not likely to increase the risk of neck 
injury. However, the agency agrees with AAMA that further exploration 
of the risk of neck injury should be conducted. With respect to 
potential auditory system injury, the existing data are not sufficient 
for NHTSA to explore the issue at this time. The agency notes that the 
SAE is currently studying the problem of air bag noise. At this time, 
NHTSA is declining to incorporate any limits relating to auditory 
injury in the final rule, but will continue to monitor air bag data and 
study occupant injuries.

I. Other Issues

    Several commenters also asked that certain issues in the proposal 
be explained or clarified. Volvo requested the agency to more fully 
define those target points contiguous to the system's mounting and 
inflation components subject to the 24 km/h (15 mph) impact. AAMA 
requested that S6.1 (b) and (c) be redrafted or explained as it 
believed that these sentences are incomplete. The organization also 
asked for clarification of S8.13.3 concerning the exclusion of the 
initial FMH forehead-to-target contact found in Option 1 when testing a 
deployed system under proposed Option 2. VW commented that testing 
laboratory contractors must confirm target locations and impact speeds 
with manufacturers before conducting the test.
    With respect to Volvo's comments requesting clarification of target 
points subject to the 24 km/h (15 mph) impact, the final rule excludes 
target points that are within the 50 mm (2.0 inch) areas surrounding 
the stowed system including its mounting and inflation units. This 
change from the Option 3 proposal should address Volvo's concern. With 
respect to the AAMA's concern on the text of S6.1 (b) and (c) and S6.2 
(b) and (c), NHTSA has redrafted and reorganized the text of the 
section in order to clarify them. With respect to AAMA's comment 
regarding excluding initial FMH forehead-to-target contact (S8.13.3) in 
testing the deployed system, clarification of S8.13.3 is not needed 
because the Option 2 test procedure has been removed from the final 
rule. NHTSA disagrees with VW's position that a NHTSA testing 
contractor should confirm target locations and impact speed before 
conducting a compliance test. It is NHTSA's position that such a 
procedure would provide manufacturers with too much control over 
compliance testing. As with other safety standards, if any information 
is needed prior to a compliance test, NHTSA will ask for, and 
manufacturers will provide, that information.
    Advocates commented that the data used by NHTSA to justify the 19 
km/h (12 mph) FMH impact test were not available for public review and 
that the administrative record of the NPRM does not support the 
reduction of the FMH impact speed from 24 km/h to 19 km/h (15 mph to 12 
mph) for target points that are located over a stowed system. Advocates 
also commented that since no sensor design specification is given to 
ensure the sensor performance, the number of severe injuries due to 
sensor malfunction may be considerably larger than the agency's 
expectation. In addition, Advocates questioned the validity of the 
agency's benefit analysis because it was based on the ITS sled tests 
generated by manufacturers and because not a single ITS test was 
conducted simulating rollover crashes. Advocates further stated that it 
is improper for NHTSA to argue for or rely on anti-ejection benefits 
that have not been tested. Both AAMA and Advocates raised questions on 
the potential risk of neck injury and urged that the topics be entered 
on the agenda of the Motor Vehicle Safety Research Advisory Committee 
and the program of International Harmonization Research Agenda. AAMA 
also raised questions on the potential risk of other injuries such as 
auditory system injuries and other injuries related to the system 
deployment.
    NHTSA does not agree with allegation made by Advocates regarding 
the administrative record and justification for the reduction of FMH 
impact speed from 24 km/h to 19 km/h (15 mph to 12 mph) for targets 
located over the stowed system. The BMW test data, although 
confidential, were used by the agency to justify the reduction of FMH 
impact speed. NHTSA believes that an adequate explanation of this data, 
given in the PRE supporting the NPRM, exists in the administrative 
record of this rulemaking. The safety benefit analysis by K. Digges & 
Associates, recently submitted by BMW in its comments to the NPRM, 
provides further justification on the subject.
    Advocates questioned the validity of the agency's benefit analysis 
because the analysis was based on ITS performance in manufacturer-
generated sled tests, the ejection prevention capability of the ITS was 
projected without testing, and the proposed rule did not contain 
specifications for sensor performance. With respect to the validity of 
the BMW sled test data, NHTSA observes that the agency's safety benefit 
estimate was based on all available data, including crash test data and 
sled test data. While NHTSA recognizes the limitations of sled tests, 
the agency believes that sled tests can be a useful tool for the 
development of safety countermeasures and are valid in this instance. 
With respect to the projections regarding ejection mitigation, NHTSA 
notes that it is true that neither the agency nor any manufacturers had 
conducted any rollover tests using the ITS system prior to issuance of 
the NPRM. However, the agency examined the limited rollover test data 
and the real world crash data and, relying on its judgment and 
experience, made an appropriate benefit estimate in support of the 
NPRM. At present, the agency has completed three rollover tests at 48.3 
km/h (30 mph) using the Standard 208 rollover cart. The test vehicles 
were Ford Explorers equipped with several different ITS designs. In 
each test, two Hybrid III dummies were seated in the outboard front 
seating positions. All dummies, except one right front seat passenger 
dummy, were unbelted. The test results showed that head ejections and 
complete ejections through side windows did not occur and that five out 
of the six test dummies had their hands/arms outside the windows after 
those rollover tests. These test results support the agency's 
assumption that the ITS system would greatly reduce the side window 
ejection casualties. In addition,

[[Page 41463]]

a recent safety benefit analysis by K. Digges & Associates provides 
further information on the subject. Based on those recent studies, it 
is concluded that the ITS and similar head protection systems will 
reduce side window ejections. However, the agency will continue 
investigation on this subject.
    With respect to the lack of sensor specifications in the proposed 
rule, NHTSA believes that such specifications are not required. The 
agency notes that it did not issue a sensor specification for the 
frontal air bag systems and that manufacturers have gained considerable 
field experience in sensor designs since the introduction of the air 
bag systems nearly 10 years ago. In addition, many manufacturers have 
already installed side air bags in their production cars. In view of 
this, it appears that a sensor specification would be superfluous.

J. Dummy Seating Position

    Agency testing has revealed that the dummy seating position 
proposed in the NPRM would result in interference between the B-pillar 
and the head of the test dummy in certain vehicles. Therefore, the 
final rule modifies the seating position to further increase the chance 
that a 2-inch head/window frame clearance will exist between the dummy 
head and the forward edge of the B-pillar/door window frame 
combination. Accordingly, S8.28 has been modified to specify that in 
those instances where the seating procedure and seat position 
procedures of S6.3, S6.4 and S7 of Standard 214 result in the back of 
the dummy head being less than 50 mm (2 inches) forward of the front 
edge of the B-pillar/door window frame combination, the seat is to be 
further adjusted to achieve the desired clearance. The first specified 
adjustment is to move the seatback forward a maximum of five degrees. 
If this does not result in sufficient clearance, the seat itself is to 
be moved forward until clearance is obtained or interference occurs 
between the dummy's knees and the dashboard or knee bolster. If forward 
adjustment of the seat does not produce the desired clearance, the seat 
back is adjusted again until clearance is obtained or until the seat is 
in its full upright locking position.

K. Selection of Options

    NHTSA notes that, where a safety standard provides manufacturers 
more than one compliance option, the agency needs to know which option 
has been selected in order to conduct a compliance test. The agency is 
aware that a manufacturer confronted with an apparent noncompliance for 
the option it has selected (based on a compliance test) may argue that 
its vehicles would comply with a different option for which the agency 
has not conducted a compliance test. This could create difficulties in 
assessing the vehicle's compliance.
    To address this problem, the proposed rule stated that 
manufacturers must select a test option prior to, or at the time of, 
certification. NHTSA did not receive any comments on this proposed 
provision. The final rule requires that where manufacturer options are 
specified, the manufacturer must select the option by the time it 
certifies the vehicle and may not thereafter select a different option. 
This will mean that failure to comply with the selected option will 
constitute a noncompliance with the standard regardless of whether a 
vehicle complies with another option.

L. Effective Date

    Volvo and BMW commented that the final rule should be issued by 
March 1998 and become effective 30 days after its issuance. VW 
commented that the final rule should be issued as soon as possible with 
an immediate effective date. In the NPRM, the agency proposed that the 
final rule become effective 30 days after publication to facilitate the 
early introduction of dynamic systems that may be in an advanced stage 
of development or actually in production. However, NHTSA notes that the 
changes incorporated into the final rule are intended to allow the 
introduction of dynamic systems and more conventional countermeasures 
needed to meet the head impact protection requirements. As the phase-in 
of the head impact protection requirements begins on September 1, 1998, 
the agency notes that it is not legally necessary to establish an 
earlier effective date in order for manufacturers to take advantage of 
the amendments made by this final rule. Accordingly, the effective date 
of the amendments is September 1, 1998. NHTSA is aware, however, that 
production of vehicles with dynamic systems began prior to the 
effective date of the final rule and is allowing manufacturers of such 
vehicles to include them in their calculation of complying vehicles 
under S6.1.5 if such vehicles meet the requirements of S6.1(b) as 
promulgated in the final rule.

III. Rulemaking Analyses and Notices

A. Executive Order 12866 and DOT Regulatory Policies and Procedures

    NHTSA has considered the impact of this final rule under E.O. 12866 
and the Department of Transportation's regulatory policies and 
procedures. This rule was not reviewed under E.O. 12866, ``Regulatory 
Planning and Review'' and is not considered significant under the 
Department of Transportation's regulatory policies and procedures.
    The agency has prepared a Final Regulatory Evaluation describing 
the economic and other effects of this rulemaking action. For persons 
wishing to examine the full analysis, a copy is being placed in the 
docket.

B. Regulatory Flexibility Act

    NHTSA has also considered the effects of this final rule under the 
Regulatory Flexibility Act. I hereby certify that it will not have a 
significant economic impact on a substantial number of small entities. 
While the cost of new passenger cars or light trucks equipped with 
dynamically deployed upper interior head protection systems will be 
slightly increased by the amendments, the rule establishes optional 
test procedures which manufacturers need only use in the event they 
equip their vehicles with a dynamically deployed head impact protection 
system. Further, the amendments primarily affect passenger car and 
light truck manufacturers which are not small entities under 5 U.S.C. 
Sec. 605(b). The Small Business Administration's regulations at 13 CFR 
Part 121 define a small business, in part, as a business entity ``which 
operates primarily within the United States.'' (13 CFR 
Sec. 121.105(a)). The agency estimates that there are at most five 
small final stage manufacturers of passenger cars in the U.S. and no 
small manufacturers of light trucks, producing a combined total of at 
most 500 cars each year.
    The primary effect of the final rule will be on manufacturers of 
passenger cars and LTVs. If LTVs are produced with these systems some 
time in the future and provided as incomplete vehicles to final stage 
manufacturers, which are generally small businesses, these final stage 
manufacturers may have to certify compliance. However, as noted above, 
the amendments in this final rule do not impose any additional 
mandatory requirements that all manufacturers or final stage 
manufacturers must meet. Instead, these amendments provide a means for 
evaluating advanced dynamically deployed upper interior head protection 
systems where manufacturers choose to install them.
    Manufacturer associations could also sponsor generic tests to 
determine the amount and type of padding or design of dynamic system 
needed for basic structures that will be used by a number of final 
stage manufacturers, to reduce

[[Page 41464]]

certification costs. Final stage manufacturers may also avoid any 
additional certification or compliance costs by relying on the 
certification provided by the manufacturer of the incomplete vehicle.
    Other entities which qualify as small businesses, small 
organizations and governmental units will be affected by this rule to 
the extent that they purchase passenger cars and LTVs. They will not be 
significantly affected, since the potential cost increases associated 
with this action should only slightly affect the purchase price of new 
motor vehicles.

C. 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.

D. Executive Order 12612 (Federalism) and Unfunded Mandates Act

    The agency has analyzed this rulemaking action in accordance with 
the principles and criteria set forth in Executive Order 12612. NHTSA 
has determined that the amendment does not have sufficient federalism 
implications to warrant the preparation of a Federalism Assessment.
    In issuing this final rule to permit optional testing to 
accommodate dynamic head protections systems, the agency notes, for the 
purposes of the Unfunded Mandates Act, that it is pursuing the least 
cost alternative. As noted above, any manufacturer may choose one of 
two options to test for compliance with Standard 201, including the 
test procedure established in the August 18, 1995 final rule. As this 
rulemaking does not require manufacturers to meet new minimum 
performance requirements but sets minimum performance criteria for 
optional systems, it does not impose new costs.

E. Civil Justice Reform

    This amendment does not have any retroactive effect. Under 49 
U.S.C. 21403, whenever a Federal motor vehicle safety standard is in 
effect, a State may not adopt or maintain a safety standard applicable 
to the same aspect of performance which is not identical to the Federal 
standard, except to the extent that the state requirement imposes a 
higher level of performance and applies only to vehicles procured for 
the State's use. 49 U.S.C. 21461 sets forth a procedure for judicial 
review of final rules establishing, amending or revoking Federal motor 
vehicle safety standards. That section does not require submission of a 
petition for reconsideration or other administrative proceedings before 
parties may file suit in court.

List of Subjects in 49 CFR Part 571

    Imports, Motor vehicle safety, Motor vehicles, Rubber and rubber 
products, Tires.
    In consideration of the foregoing, 49 CFR part 571 is amended as 
follows:

PART 571.201--[AMENDED]

    1. The authority citation for part 571 continues to read as 
follows:

    Authority: 49 U.S.C. 322, 30111, 30115, 30117, and 30166; 
delegation of authority at 49 CFR 1.50.

    2. Section 571.201 is amended by adding a definition of Dynamically 
Deployed Upper Interior Head Protection System to S3, revising S6.1, 
S6.2, S7, and S8.13.3 and by adding S8.16 through S8.28 as follows:


Sec. 571.201  Standard No. 201; Occupant protection in interior impact.

* * * * *
    S3.  Definitions.
* * * * *
    Dynamically deployed upper interior head protection system means a 
protective device or devices which are integrated into a vehicle and 
which, when activated by an impact, provide, through means requiring no 
action from occupants, protection against head impacts with upper 
interior structures and components of the vehicle in crashes.
* * * * *
    S6.1  Vehicles manufactured on or after September 1, 1998 and 
before September 1, 2002. Except as provided in S6.3, for vehicles 
manufactured on or after September 1, 1998 and before September 1, 
2002, a percentage of the manufacturer's production, as specified in 
S6.1.1, S6.1.2, S6.1.3, or S6.1.4, shall conform, at the manufacturer's 
option, to either S6.1(a) or S6.1(b). The manufacturer shall select the 
option by the time it certifies the vehicle and may not thereafter 
select a different option for the vehicle.
    (a) When tested under the conditions of S8, comply with the 
requirements specified in S7 at the target locations specified in S10 
when impacted by the free motion headform specified in S8.9 at any 
speed up to and including 24 km/h (15 mph). The requirements do not 
apply to any target that cannot be located using the procedures of S10.
    (b) When equipped with a dynamically deployed upper interior head 
protection system and tested under the conditions of S8, comply with 
the requirements specified in S7 at the target locations specified in 
S10 as follows:
    (1) Targets that are not located over any point inside the area 
measured along the contour of the vehicle surface within 50 mm (2.0 
inch) of the periphery of the stowed system projected perpendicularly 
onto the vehicle interior surface, including mounting and inflation 
components but exclusive of any cover or covers, shall be impacted by 
the free motion headform specified in S8.9 at any speed up to and 
including 24 km/h (15 mph). The requirements do not apply to any 
targets that can not be located by using the procedures of S10.
    (2) Targets that are over any point inside the area measured along 
the contour of the vehicle interior within 50 mm (2.0 inch) of the 
periphery of the stowed system projected perpendicularly onto the 
vehicle interior surface, including mounting and inflation components 
but exclusive of any cover or covers, when the dynamically deployed 
upper interior head protection system is not deployed, shall be 
impacted by the free motion headform specified in S8.9 at any speed up 
to and including 19 km/h (12 mph) with the system undeployed. The 
requirements do not apply to any target that can not be located using 
the procedures of S10.
    (3) Each vehicle shall, when equipped with a dummy test device 
specified in part 572, subpart M, and tested as specified in S8.16 
through S8.28, comply with the requirements specified in S7 when 
crashed into a fixed, rigid pole of 254 mm in diameter, at any velocity 
up to and including 29 kilometers per hour (18 mph).
* * * * *
    S6.2  Vehicles manufactured on or after September 1, 2002. Except 
as provided in S6.3, vehicles manufactured on or after September 1, 
2002 shall, when tested under the conditions of S8, conform, at the 
manufacturer's option, to either S6.2(a) or S6.2(b). The manufacturer 
shall select the option by the time it certifies the vehicle and may 
not thereafter select a different option for the vehicle.
    (a) When tested under the conditions of S8, comply with the 
requirements specified in S7 at the target locations specified in S10 
when impacted by the free motion headform specified in S8.9 at any 
speed up to and including 24 km/h (15 mph). The requirements do not 
apply to any target that cannot be located using the procedures of S10.

[[Page 41465]]

    (b) When equipped with a dynamically deployed upper interior head 
protection system and tested under the conditions of S8, comply with 
the requirements specified in S7 at the target locations specified in 
S10 as follows:
    (1) Targets that are not located over any point inside the area 
measured along the contour of the vehicle surface within 50 mm (2.0 
inch) of the periphery of the stowed system projected perpendicularly 
onto the vehicle interior surface, including mounting and inflation 
components but exclusive of any cover or covers, shall be impacted by 
the free motion headform specified in S8.9 at any speed up to and 
including 24 km/h (15 mph). The requirements do not apply to any 
targets that cannot be located by using the procedures of S10.
    (2) Targets that are over any point inside the area measured along 
the contour of the vehicle interior within 50 mm (2.0 inch) of the 
periphery of the stowed system projected perpendicularly onto the 
vehicle interior surface, including mounting and inflation components 
but exclusive of any cover or covers, when the dynamically deployed 
upper interior head protection system is not deployed, shall be 
impacted by the free motion headform specified in S8.9 at any speed up 
to and including 19 km/h (12 mph) with the system undeployed. The 
requirements do not apply to any target that cannot be located using 
the procedures of S10.
    (3) Each vehicle shall, when equipped with a dummy test device 
specified in part 572, subpart M, and tested as specified in S8.16 
through S8.28, comply with the requirements specified in S7 when 
crashed into a fixed, rigid pole of 254 mm in diameter, at any velocity 
up to and including 29 kilometers per hour (18 mph).
* * * * *
    S7  Performance Criterion. The HIC(d) shall not exceed 1000 when 
calculated in accordance with the following formula:
[GRAPHIC] [TIFF OMITTED] TR04AU98.002

Where the term a is the resultant head acceleration expressed as a 
multiple of g (the acceleration of gravity), and t1 and t2 are any two 
points in time during the impact which are separated by not more than a 
36 millisecond time interval.
    (a) For the free motion headform; HIC(d)=0.75446 (free motion 
headform HIC)+166.4.
    (b) For the part 572, subpart M, anthropomorphic test dummy; 
HIC(d)=HIC.
    S8  Target location and test conditions.
* * * * *
    S8.13  Impact configuration.
* * * * *
    S8.13.3  At the time of initial contact between the headform and 
the vehicle interior surface, some portion of the forehead impact zone 
of the headform must contact some portion of the target circle.
* * * * *
    S8.16  Test weight--vehicle to pole test. Each vehicle shall be 
loaded to its unloaded vehicle weight, plus 136 kilograms (300 pounds) 
or its rated cargo and luggage capacity (whichever is less), secured in 
the luggage or load-carrying area, plus the weight of the necessary 
anthropomorphic test dummy. Any added test equipment shall be located 
away from impact areas in secure places in the vehicle.
    S8.17  Vehicle test attitude--vehicle to pole test. Determine the 
distance between a level surface and a standard reference point on the 
test vehicle's body, directly above each wheel opening, when the 
vehicle is in its ``as delivered'' condition. The ``as delivered'' 
condition is the vehicle as received at the test site, filled to 100 
percent of all fluid capacities and with all tires inflated to the 
manufacturer's specifications listed on the vehicle's tire placard. 
Determine the distance between the same level surface and the same 
standard reference points in the vehicle's ``fully loaded condition.'' 
The ``fully loaded condition'' is the test vehicle loaded in accordance 
with S8.16. The load placed in the cargo area shall be centered over 
the longitudinal centerline of the vehicle. The pretest vehicle 
attitude shall be the same as either the ``as delivered'' or ``fully 
loaded'' attitude or is between the ``as delivered'' attitude and the 
``fully loaded'' attitude. If the test configuration requires that the 
vehicle be elevated off the ground, the pretest vehicle attitude must 
be maintained.
    S8.18  Adjustable seats--vehicle to pole test. Initially, 
adjustable seats shall be adjusted as specified in S6.3 of Standard 214 
(49 CFR 571.214).
    S8.19  Adjustable seat back placement--vehicle to pole test. 
Initially, position adjustable seat backs in the manner specified in 
S6.4 of Standard 214 (49 CFR 571.214).
    S8.20  Adjustable steering wheels--vehicle to pole test. Adjustable 
steering controls shall be adjusted so that the steering wheel hub is 
at the geometric center of the locus it describes when it is moved 
through its full range of driving positions.
    S8.21  Windows and sunroof--vehicle to pole test. Movable windows 
and vents shall be placed in the fully open position. Any sunroof shall 
be placed in the fully closed position.
    S8.22  Convertible tops--vehicle to pole test. The top, if any, of 
convertibles and open-body type vehicles shall be in the closed 
passenger compartment configuration.
    S8.23  Doors--vehicle to pole test. Doors, including any rear 
hatchback or tailgate, shall be fully closed and latched but not 
locked.
    S8.24  Impact reference line--vehicle to pole test. On the striking 
side of the vehicle, place an impact reference line at the intersection 
of the vehicle exterior and a transverse vertical plane passing through 
the center of gravity of the head of the dummy seated in accordance 
with S8.28, in the front outboard designated seating position.
    S8.25  Rigid Pole--vehicle to pole test. The rigid pole is a 
vertical metal structure beginning no more than 102 millimeters (4 
inches) above the lowest point of the tires on the striking side of the 
test vehicle when the vehicle is loaded as specified in S8.16 and 
extending above the highest point of the roof of the test vehicle. The 
pole is 254 mm 3 mm (10 inches) in diameter and set off 
from any mounting surface, such as a barrier or other structure, so 
that the test vehicle will not contact such a mount or support at any 
time within 100 milliseconds of the initiation of vehicle to pole 
contact.
    S8.26  Impact configuration--vehicle to pole test. The rigid pole 
shall be stationary. The test vehicle shall be propelled sideways so 
that its line of forward motion forms an angle of 90 degrees 
(3 degrees) with the vehicle's longitudinal center line. 
The impact reference line shall be aligned with the center line of the 
rigid pole so that, when the vehicle-to-pole contact occurs, the center 
line of the pole contacts the vehicle area bounded by two transverse 
vertical planes 38 mm (1.5 inches) forward and aft of the impact 
reference line.
    S8.27  Anthropomorphic test dummy--vehicle to pole test. 
    S8.27.1  The anthropomorphic test dummy used for evaluation of a 
vehicle's head impact protection shall conform to the requirements of 
subpart M of part 572 of this chapter (49 CFR part 572, subpart M). In 
a test in which the test vehicle is striking its left side, the dummy 
is to be configured and instrumented to strike on its left side, in 
accordance with subpart M of part 572.

[[Page 41466]]

In a test in which the test vehicle is striking its right side, the 
dummy is to be configured and instrumented to strike its right side, in 
accordance with subpart M of part 572.
    S8.27.2  The part 572, subpart M, test dummy specified is clothed 
in form fitting cotton stretch garments with short sleeves and midcalf 
length pants. Each foot of the test dummy is equipped with a size 11EEE 
shoe, which meets the configuration size, sole, and heel thickness 
specifications of MIL-S-13192 (1976) and weighs 0.57 0.09 
kilograms (1.25 0.2 pounds).
    S8.27.3  Limb joints shall be set at between 1 and 2 g's. Leg 
joints are adjusted with the torso in the supine position.
    S8.27.4  The stabilized temperature of the test dummy at the time 
of the side impact test shall be at any temperature between 20.6 
degrees C. and 22.2 degrees C., and at any relative humidity between 10 
percent and 70 percent.
    S8.27.5  The acceleration data from the accelerometers installed 
inside the skull cavity of the test dummy are processed according to 
the practices set forth in SAE Recommended Practice J211, March 1995, 
``Instrumentation for Impact Tests,'' Class 1000.
    S8.28  Positioning procedure for the Part 572 Subpart M Test 
Dummy--vehicle to pole test. The part 572, subpart M, test dummy shall 
be initially positioned in the front outboard seating position on the 
struck side of the vehicle in accordance with the provisions of S7 of 
Standard 214, 49 CFR 571.214, and the vehicle seat shall be positioned 
as specified in S6.3 and S6.4 of that standard. The position of the 
dummy shall then be measured as follows. Locate the horizontal plane 
passing through the dummy head center of gravity. Identify the rearmost 
point on the dummy head in that plane. Construct a line in the plane 
that contains the rearward point of the front door daylight opening and 
is perpendicular to the longitudinal vehicle centerline. Measure the 
longitudinal distance between the rearmost point on the dummy head and 
this line. If this distance is less than 50 mm (2 inches) or the point 
is not forward of the line, then the seat and/or dummy positions shall 
be adjusted as follows. First, the seat back angle is adjusted, a 
maximum of 5 degrees, until a 50 mm (2 inches) distance is achieved. If 
this is not sufficient to produce the 50 mm (2 inches) distance, the 
seat is moved forward until the 50 mm (2 inches) distance is achieved 
or until the knees of the dummy contact the dashboard or knee bolster, 
whichever comes first. If the required distance cannot be achieved 
through movement of the seat, the seat back angle shall be adjusted 
even further forward until the 50mm (2 inches) distance is obtained or 
until the seat back is in its full upright locking position.
* * * * *
    Issued on July 29, 1998.
Ricardo Martinez,
Administrator.
[FR Doc. 98-20700 Filed 7-30-98; 3:39 pm]
BILLING CODE 4910-59-P