Federal Motor Vehicle Safety Standards; Head Impact Protection

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

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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

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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

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\1\ Advocates evidently misread NHTSA's evaluation of additional

deaths and injuries. The agency estimate was in fact far lower--4

fatalities.

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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