[Federal Register Volume 62, Number 3 (Monday, January 6, 1997)]
[Proposed Rules]
[Pages 807-831]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 96-33307]



  Federal Register / Vol. 62, No. 3 / Monday, January 6, 1997 / 
Proposed Rules  

[[Page 807]]


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DEPARTMENT OF TRANSPORTATION

National Highway Traffic Safety Administration

49 CFR Part 571

[Docket No. 74-14; Notice 108]
RIN 2127-AG59


Federal Motor Vehicle Safety Standards; Occupant Crash Protection

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

ACTION: Notice of proposed rulemaking (NPRM).

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

SUMMARY: NHTSA is proposing to amend the agency's occupant crash 
protection standard to ensure that vehicle manufacturers can depower 
all air bags so that they inflate less aggressively. The agency is 
taking this action as part of its comprehensive efforts to reduce the 
fatalities and injuries that current air bag designs are causing in 
relatively low speed crashes to small, but growing numbers of children, 
and occasionally to adult drivers. Taken together, these efforts would 
affect all existing air bag vehicles, as well as those produced in the 
next several model years.
    Based on agency research and analysis regarding the optimal range 
of air bag ``depowering,'' the agency has tentatively concluded that an 
average depowering of 20 to 35 percent would reduce the risk of 
fatalities in low speed crashes, while substantially preserving the 
life saving capabilities of air bags in higher speed crashes. The 
agency is considering the adoption of either, or both, of two different 
approaches that would permit or facilitate, but not require, such 
depowering of current air bags. One approach would be to reduce the 
stringency of the chest acceleration requirement which an unbelted 
dummy must meet in a crash test at speeds up to 30 mph. The other 
approach was recently requested by the American Automobile 
Manufacturers Association in a letter superseding its earlier petition 
for rulemaking. It would replace the unbelted crash test requirement 
with a sled test protocol incorporating a 125 millisecond standardized 
crash pulse. NHTSA is seeking comments and information concerning the 
relative desirability of these two approaches, including supporting 
data from industry for the sled test. The agency also seeks comments on 
whether the same or different requirements should apply to the 
passenger and driver positions.
    There is a possibility that while this rulemaking would prevent a 
significant number of air bag fatalities, and make it possible to 
design air bags so that they save increased numbers of belted 
occupants, it could also result in an even larger number of unbelted 
occupants not being saved by air bags. Accordingly, the agency is 
requesting comments on the appropriate duration of such an amendment. 
If there are adverse safety tradeoffs, and smart air bags offer a way 
of preventing air bag fatalities while not causing similar tradeoffs, 
it would be desirable to limit the duration of the amendment so that 
depowering is only an interim measure. NHTSA currently contemplates 
that the amended requirement would remain in effect for both passenger 
and driver air bags until smart air bags are installed pursuant to a 
mandated phase-in schedule. Establishing that schedule and appropriate 
performance requirements will be the subject of a separate rulemaking 
proceeding.
    NHTSA is also announcing its granting of a petition by Anita Glass 
Lindsey to commence a rulemaking proceeding to consider whether to 
specify the use of a dummy representing a small-statured female in 
testing the performance of safety belts and air bags.

DATES: Comments must be received by February 5, 1997.

ADDRESSES: Comments should refer to the docket and notice number of 
this notice and be submitted to: Docket Section, Room 5109, National 
Highway Traffic Safety Administration, 400 Seventh Street, SW, 
Washington, DC 20590. (Docket Room hours are 9:30 a.m.-4 p.m., Monday 
through Friday.)

FOR FURTHER INFORMATION CONTACT: For information about air bags and 
related rulemakings: Visit the NHTSA web site at http://
www.nhtsa.dot.gov and select ``AIR BAGS: Information about air bags.''
    For non-legal issues: Mr. Clarke Harper, Chief, Light Duty Vehicle 
Division, NPS-11, National Highway Traffic Safety Administration, 400 
Seventh Street, SW, Washington, DC 20590. Telephone: (202) 366-2264. 
Fax: (202) 366-4329.
    For legal issues: J. Edward Glancy, Office of Chief Counsel, NCC-
20, National Highway Traffic Safety Administration, 400 Seventh Street, 
SW, Washington, DC 20590. Telephone: (202) 366-2992. Fax: (202) 366-
3820.

SUPPLEMENTARY INFORMATION:

Table of Contents

I. Background.
    A. How Air Bags Work.
    B. Circumstances of Air Bag Fatalities.
II. The Safety Problem: Frontal Impacts and Air Bags--Lives Saved, 
and Lives Lost.
    A. Frontal Impacts.
    B. Air Bags: Lives Saved, and Lives Lost.
III. Search for Solutions.
    A. The Early Years.
    B. The Last Five Years.
    C. Recent Petitions for Rulemaking.
IV. Overview of Comprehensive NHTSA Plan for Addressing Problem.
V. Depowering Air Bags
    A. Results of NHTSA Test Program
    B. Effects of Depowering and Optimizing
    1. Passenger Air Bags
    2. Driver Air Bags
    C. Alternative Proposals
    1. Approach I--Temporary Change in Unbelted Chest Acceleration 
Requirement.
    2. Approach II--Temporary Replacement of Unbelted Crash Test 
Requirement with a Sled Test Protocol Incorporating a Standardized 
Crash Pulse.
    3. Request for Additional Information.
    D. Consideration of Other Alternatives.
    E. Effective Date and Comment Period.
    F. Relationship to Other Actions.
VI. Response to AAMA and CFAS Petitions.
VII. Granting of Petition to Consider Using 5th Percentile Female 
Dummy.
VIII. Rulemaking Analyses and Notices.
    A. Executive Order 12866 and DOT Regulatory Policies and 
Procedures.
    B. Regulatory Flexibility Act.
    C. National Environmental Policy Act.
    D. Executive Order 12612 (Federalism).
    E. Civil Justice Reform.
IX. Request for Comments.
Appendix: Past Public Comments Related to Depowering Air Bags.

I. Background

    In 1984, the Department of Transportation issued a final rule 
requiring the installation of automatic protection (e.g., air bags, 
automatic belts, passive interiors) in passenger cars. 49 Fed. Reg. 
28962; July 17, 1984. The Department took this step to increase the 
protection of vehicle occupants, especially unbelted ones. At the time, 
only 12.5 percent of occupants wore their safety belts, and only one 
state required all motorists to buckle up.
    In 1991, Congress mandated the installation of air bags in both 
passenger cars and LTV's with a gross vehicle weight rating (GVWR) of 
8,500 pounds or less. (LTV's generally include vans, pickup trucks, 
buses, and sport utility vehicles with a gross vehicle weight rating of 
10,000 pounds or less). The Intermodal Surface Transportation 
Efficiency Act required that air bags be put in all new cars by the 
beginning of model year 1998 and in all new LTV's by the beginning of 
model year 1999.
    Much has changed since 1984, and even since 1991. The cumulative 
production of air bag cars and LTV's reached the 10,000,000 mark for 
driver air bag vehicles during model year 1992 and for dual air bag 
vehicles during model year 1995. Air bags are now standard equipment on 
most passenger

[[Page 808]]

cars and LTV's. As of the end of model year 1996, approximately 56 
million air bag vehicles have been produced for sale in the United 
States. 1 Safety belt use has reached approximately 68 percent. 
2 Forty-nine States and the District of Columbia require the use 
of safety belts, and all jurisdictions require the use of child safety 
seats. While males account for a sizable majority of the nonusers of 
safety belts, females still account for 40 percent of the nonusers. 
3
---------------------------------------------------------------------------

    \1\ Over 27,000,000 of those vehicles have both driver and 
passenger air bags.
    \2\ Belt use among fatally injured front seat occupants of cars 
and LTV's is lower, approximately 37 percent, based on 1995 data 
from the Fatal Accident Reporting System (FARS). The lowness of this 
rate reflects a number of factors, including the belt use rate by 
motorists in general and the effectiveness of belt use in preventing 
fatal injury. A more useful belt use rate is the rate among 
occupants involved in potentially fatal crashes. Those crashes 
include all fatal crashes as well as all crashes in which there 
would have been a fatality but for belt use. The use rate in 
potentially fatal crashes is slightly over 50 percent.
    \3\ This figure is based on a September 1994 study by Reinfurt 
et al. of belt use in North Carolina.
---------------------------------------------------------------------------

    NHTSA estimates that air bags have deployed more than 800,000 times 
in crashes and have saved approximately 1,664 lives (164 passengers and 
1,500 drivers) as of November 1996. Unfortunately, air bags also have 
fatally injured at least 32 children, 1 adult passenger, and 19 drivers 
in low severity crashes in the United States. Apart from the nine 
fatally-injured infants (included in the figure of 32 above), most of 
the fatally-injured occupants were unbelted. Thus, while the number of 
people being saved by air bags is growing annually, so is the much 
smaller, but significant number of people being fatally injured by air 
bags.

A. How Air Bags Work

    When a vehicle has a frontal impact, its occupants begin to move 
forward in response to pre-impact braking or the deceleration of the 
vehicle during the impact. If unrestrained, front-seat occupants will 
move forward in a fraction of a second and hit the steering wheel, 
dashboard or windshield. To move into place in time to catch the 
occupants in moderate and high speed crashes, air bags must inflate 
very quickly--faster than the blink of an eye.
    To ensure that the air bag provides enough resistance to keep large 
as well as small occupants from ``bottoming out'' the air bag and 
hitting the vehicle interior, the amount of gaseous pressure within air 
bags must be carefully modulated. This is done by controlling both the 
rate at which gas is pumped into the air bag as well as the rate at 
which the gas is released from the air bag through vents or the 
porosity of the fabric.
    An example from a non-automotive context will help to show the 
importance of modulating the air pressure in air bags. Vented air 
cushions are sometimes used by stunt performers who jump or dive from a 
great height to absorb the energy of their fall. If the vents don't 
allow enough of the pressure in the cushion to be released as the 
performer hits it, the cushion will be too rigid and will fail to 
absorb enough of the performer's energy, causing injury. On the other 
hand, if the vents release too much pressure, the cushion will ``bottom 
out,'' thus allowing the performer to strike the ground, also causing 
injury.

B. Circumstances of Air Bag Fatalities

    Air bags need time, and space, to inflate. The sudden release of 
energy by an inflating air bag can harm some front seat occupants, 
particularly if they are too close to the air bag at the time of 
deployment. Properly restrained occupants of a vehicle seat moved back 
from the dashboard as far as possible, and even most unrestrained 
teenagers and adults, will meet the air bag after the initial, sudden 
release of energy. However, some occupants either start out very close 
to the steering wheel or dashboard or end up there. Most child 
fatalities attributed to an air bag fall into one of two groups: (1) 
infants riding in rear-facing infant seats, thus placing them very 
close to the air bag at the time of deployment, or (2) older children 
riding forward-facing without any type of restraint, thus allowing them 
to slide forward during pre-crash braking so that they were too close 
to the air bag when it deployed. A majority of the fatally-injured 
drivers were short-statured women who moved the driver's seat forward. 
More than half of the fatally-injured drivers were not using any type 
of restraint.

II. The Safety Problem: Frontal Impacts and Air Bags--Lives Saved, and 
Lives Lost

    The number of air bag fatalities and the likelihood of those 
fatalities must be carefully compared to the likelihood of other 
related events in evaluating solutions to the causes of those 
fatalities.

A. Frontal Impacts

    Frontal impacts are the number one fatality and injury-causing mode 
of crash, resulting in 64 percent of all driver and right-front 
passenger fatalities and 65 percent of all driver and right-front 
passenger AIS 2-5 injuries. (AIS 2-5 stands for Abbreviated Injury 
Scale levels of moderate to critical injuries.) The estimated fatality 
and injury totals for 1994 are shown below. The injuries are those for 
National Accident Sampling System-Crashworthiness Data System (NASS-
CDS) towaway accidents only. (See table below.)

   1994 Fatalities and Moderate to Serious Injuries in Frontal Impacts  
                    [Passenger Cars and Light Trucks]                   
------------------------------------------------------------------------
                                                  Right front           
                                        Drivers    passengers    Total  
------------------------------------------------------------------------
Fatalities...........................     13,437        3,814     17,251
Injuries.............................    124,484       30,299    154,783
                                      ----------------------------------
      Total..........................  4 137,921     5 34,113   172,034 
------------------------------------------------------------------------
4 The numbers of fatalities and injuries for drivers far exceed those   
  for passengers in large measure because approximately 80 percent of   
  front seat occupants are drivers.                                     
5 The figures for right front passengers include the following figures  
  for children under the age of 13: approximately 266 fatalities and 643
  moderate to serious injuries.                                         


[[Page 809]]

B. Air Bags: Lives Saved, and Lives Lost

    As the agency has confronted the problem of low speed fatalities 
and injuries from air bags, it has faced a serious dilemma. On the one 
hand, air bags have proven to be highly effective in reducing 
fatalities, and are resulting in substantial net benefits in terms of 
lives saved. The agency estimates that, to date, air bags have saved 
1,664 drivers and passengers (1,500 drivers and 164 passengers).6 
Current air bags could save an estimated slightly more than 3,000 lives 
each year in passenger cars and light trucks when all cars on the road 
are equipped with dual air bags.
---------------------------------------------------------------------------

    \6\ This estimate of gross savings is cumulative, through 
November 1, 1996. The net savings would be 1,612.
---------------------------------------------------------------------------

    At the same time, air bags are actually causing fatalities in some 
situations, especially to children. As of November 30, 1996, NHTSA's 
Special Crash Investigation program had identified 32 crashes in this 
country in which the deployment of the passenger air bag resulted in 
fatal injuries to a child. The agency has examined all air bag cases 
with child fatalities in its Fatal Accident Reporting System (FARS) and 
believes it has identified all cases involving air bag-related 
fatalities. One adult passenger has been fatally injured (a woman in 
her 90's). On the driver side, 19 drivers 7 have been fatally 
injured in this country. (See table below.)
---------------------------------------------------------------------------

    \7\ The figure of 19 is based on information that NHTSA has 
developed through NHTSA's Special Crash Investigation program and is 
not a census. Studies of FARS data are underway to obtain a more 
precise figure.

  Air Bags: Cumulative Lives Saved and Fatalities Caused (1986-Present) 
                    [Passenger Cars and Light Trucks]                   
------------------------------------------------------------------------
                                                  Right front           
                                        Drivers    passengers    Total  
------------------------------------------------------------------------
Lives saved..........................      1,500          164      1,664
Fatalities caused....................         19           33         52
                                      ----------------------------------
      Net lives saved................      1,481          131      1,612
------------------------------------------------------------------------

    Passenger Fatalities. The annual number of fatalities involving 
children is steadily growing; all have occurred in 1993 and later 
calendar years. As noted above, 32 children have been fatally injured 
to date. (See tables below.)
    It appears that the children most at risk are infants in rear-
facing infant restraints and children not using any type of restraint. 
All of the infant fatalities (9) involved infants in rear-facing child 
seats. Most of the other children were not using any type of safety 
restraint. Of those other children, 18 were unrestrained, two more were 
wearing only the lap belt with the shoulder belt behind them, and two 
were wearing a lap and shoulder belt at the time of the crash. In 
addition, there was a one-year-old child who was fatally injured while 
riding in a child seat that was not belted to the vehicle seat. (See 
table below.)
    Most children were either infants or children aged 4-7 years old. 
(See table below.)
    The crashes in which the children were fatally injured involved 
pre-impact braking, and occurred at relatively low speeds. Infants in 
rear-facing child seats are very close to the dashboard even before 
pre-impact braking. As to almost all of the older children, the nonuse, 
or improper use of safety belts in conjunction with pre-impact braking 
resulted in their forward movement such that they were very close to 
the instrument panel and the air bag system when the air bag deployed. 
Because of this proximity, the children appear to have sustained fatal 
head or neck injuries from the deploying passenger air bag.
    In addition to the 32 children who have been fatally injured during 
passenger air bag deployments, as noted above, one adult, a woman in 
her 90's, sustained a fatal injury that appears to be due to an air bag 
deployment.

                                        Infant Passenger Air Bag-Related Fatalities (in Rear-Facing Infant Seats)                                       
                                                          [By MY of Vehicle and CY of Fatality]                                                         
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                                                                               Total No.      No. of    
                                                                                                                               of infant     vehicles   
                                                       CY 89    CY 90    CY 91    CY 92    CY 93    CY 94    CY 95    CY 96    passenger    produced w/ 
                                                                                                                                air bag    passenger air
                                                                                                                              fatalities       bags     
--------------------------------------------------------------------------------------------------------------------------------------------------------
MY 89...............................................  .......  .......  .......  .......  .......  .......  .......  .......  ..........          78,000
MY 90...............................................  .......  .......  .......  .......  .......  .......  .......  .......  ..........         149,000
MY 91...............................................  .......  .......  .......  .......  .......  .......  .......  .......  ..........          44,000
MY 92...............................................  .......  .......  .......  .......  .......  .......  .......  .......  ..........         421,000
MY 93...............................................  .......  .......  .......  .......  .......  .......  .......  .......  ..........       1,352,000
MY 94...............................................  .......  .......  .......  .......  .......  .......        1        1           2       5,547,000
MY 95...............................................  .......  .......  .......  .......  .......  .......        2        4           6       8,936,000
MY 96...............................................  .......  .......  .......  .......  .......  .......  .......        1           1      10,750,000
                                                     ---------------------------------------------------------------------------------------------------
      Total.........................................  .......  .......  .......  .......  .......  .......        3        6           9      27,277,000
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[[Page 810]]


                                                 Child (Non-Infant) Passenger Air Bag-Related Fatalities                                                
                                                          [By MY of Vehicle and CY of Fatality]                                                         
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                                                                               Total No.                
                                                                                                                               of child                 
                                                                                                                                 (non-        No. of    
                                                       CY 89    CY 90    CY 91    CY 92    CY 93    CY 94    CY 95    CY 96     infant)     vehicles w/ 
                                                                                                                               passenger   passenger air
                                                                                                                                air bag        bags     
                                                                                                                              fatalities                
--------------------------------------------------------------------------------------------------------------------------------------------------------
MY 89...............................................  .......  .......  .......  .......  .......  .......  .......  .......  ..........          78,000
MY 90...............................................  .......  .......  .......  .......  .......  .......  .......  .......  ..........         149,000
MY 91...............................................  .......  .......  .......  .......  .......  .......  .......  .......  ..........          44,000
MY 92...............................................  .......  .......  .......  .......  .......  .......  .......  .......  ..........         421,000
MY 93...............................................  .......  .......  .......  .......        1        1        1  .......           3       1,352,000
MY 94...............................................  .......  .......  .......  .......  .......        3        1        1           5       5,547,000
MY 95...............................................  .......  .......  .......  .......  .......        1        3        8          12       8,936,000
MY 96...............................................  .......  .......  .......  .......  .......  .......  .......        3           3      10,750,000
                                                     ---------------------------------------------------------------------------------------------------
    Total...........................................  .......  .......  .......  .......        1        5        5       12          23      27,277,000
--------------------------------------------------------------------------------------------------------------------------------------------------------


                                                 Age of Children Fatally Injured in Air Bag Deployments                                                 
--------------------------------------------------------------------------------------------------------------------------------------------------------
                          <1                              1      2      3      4      5      6      7      8      9      10     11     12     13   Total
--------------------------------------------------------------------------------------------------------------------------------------------------------
9.....................................................      1  .....      1      5      7      4      3  .....      2  .....  .....  .....  .....     32
--------------------------------------------------------------------------------------------------------------------------------------------------------


     Type of Restraint Used by Children Fatally Injured by Air Bags     
------------------------------------------------------------------------
                                                                 No. of 
                    Type of restraint used                      children
------------------------------------------------------------------------
None..........................................................        18
Lap belt only.................................................         2
Lap and shoulder belt.........................................         2
Rear-facing infant restraint attached to vehicle seat.........         9
Forward-facing child restraint attached to vehicle seat.......  ........
Booster seat..................................................  ........
Other 8.......................................................         1
                                                               ---------
    Total.....................................................       32 
------------------------------------------------------------------------
\8\ One fatally injured child was reportedly strapped into a forward    
  facing child seat, but the child seat was not attached to the vehicle 
  seat.                                                                 

    Driver Fatalities. As of November 15, 1996, NHTSA's Special Crash 
Investigation (SCI) program had identified 19 minor to moderate 
severity crashes in which fatal injuries to the driver were associated 
with the deployment of the driver air bag.9 The data suggest that 
unrestrained small-statured and/or older drivers are more at risk than 
other drivers from a driver air bag. (See tables below.) The agency 
notes that older drivers are more at risk than younger drivers under a 
wide range of crash circumstances, regardless of type of restraint 
used.
---------------------------------------------------------------------------

    \9\ But see footnote 7 below concerning reported driver 
fatalities in Canada.
---------------------------------------------------------------------------

    NHTSA notes that these driver fatalities are very rare in 
comparison to the number of vehicles equipped with driver air bags and 
to the number of drivers saved by air bags. Further, NHTSA notes that 
the last reported fatality in the United States of a female driver 5 
feet 2 inches or shorter in an air bag deployment occurred in November 
1995, 13 months ago.
    Proper belt use is important. Ten of the 19 drivers were known to 
have been unrestrained at the time of the crash. Of the six persons 
properly using both lap and shoulder belts, two appeared to be out of 
position (slumped over the wheel due to medical conditions). (See 
tables below.)

                                                Driver Air Bags: Fatalities and Lives Saved--All Drivers                                                
                                                 [Fatalities Shown by MY of Vehicle and CY of Fatality]                                                 
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                                                                                              No. of    
                                                                                                                   Driver air   Drivers      vehicles   
                                            CY 89    CY 90    CY 91    CY 92    CY 93    CY 94    CY 95    CY 96       bag      saved by    produced w/ 
                                                                                                                   fatalities   air bag     driver air  
                                                                                                                                               bags     
--------------------------------------------------------------------------------------------------------------------------------------------------------
MY 89....................................  .......  .......  .......  .......  .......  .......        1  .......           1  .........         500,000
MY 90....................................  .......        1        1  .......        1        2        1  .......           6  .........       2,500,000
MY 91....................................  .......  .......        2        2        1  .......        1  .......           6  .........       2,867,000
MY 92....................................  .......  .......  .......  .......        1        1  .......  .......           2  .........       5,084,000
MY 93....................................  .......  .......  .......  .......  .......  .......  .......  .......  ..........  .........       7,597,000
MY 94....................................  .......  .......  .......  .......  .......        2        1  .......           3  .........       9,886,000
MY 95....................................  .......  .......  .......  .......  .......  .......  .......        1           1  .........      13,686,000
MY 96....................................  .......  .......  .......  .......  .......  .......  .......  .......  ..........  .........      14,055,000
                                          --------------------------------------------------------------------------------------------------------------
    Total................................  .......        1        3        2        3        5        4        1          19      1,500      56,175,000
--------------------------------------------------------------------------------------------------------------------------------------------------------


[[Page 811]]


                                                    Driver Air Bag Fatalities--Women (5'2'' or Less)                                                    
                                                          [By MY of Vehicle and CY of Fatality]                                                         
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                                                                              Total No.                 
                                                                                                                              of driver       No. of    
                                                                                                                               air bag       vehicles   
                                                      CY 89    CY 90    CY 91    CY 92    CY 93    CY 94    CY 95    CY 96    fatalities    produced w/ 
                                                                                                                                (women      driver air  
                                                                                                                               5'2'' or        bags     
                                                                                                                                less)                   
--------------------------------------------------------------------------------------------------------------------------------------------------------
MY 89..............................................  .......  .......  .......  .......  .......  .......        1  .......            1         500,000
MY 90..............................................  .......        1  .......  .......        1  .......        1  .......            3       2,500,000
MY 91..............................................  .......  .......        1        1  .......  .......        1  .......            3       2,867,000
MY 92..............................................  .......  .......  .......  .......        1        1  .......  .......            2       5,084,000
MY 93..............................................  .......  .......  .......  .......  .......  .......  .......  .......  ...........       7,597,000
MY 94..............................................  .......  .......  .......  .......  .......  .......        1  .......            1       9,886,000
MY 95..............................................  .......  .......  .......  .......  .......  .......  .......  .......  ...........      13,686,000
MY 96..............................................  .......  .......  .......  .......  .......  .......  .......  .......  ...........      14,055,000
                                                    ----------------------------------------------------------------------------------------------------
    Total..........................................  .......        1        1        1        2        1        4  .......           10      56,175,000
--------------------------------------------------------------------------------------------------------------------------------------------------------


                                                         Driver Air Bag Fatalities--Other Adults                                                        
                                                          [By MY of Vehicle and CY of Fatality]                                                         
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                                                                               Total No.                
                                                                                                                               of driver      No. of    
                                                                                                                                air bag      vehicles   
                                                       CY 89    CY 90    CY 91    CY 92    CY 93    CY 94    CY 95    CY 96   fatalities    produced w/ 
                                                                                                                                (other      driver air  
                                                                                                                                adults)        bags     
--------------------------------------------------------------------------------------------------------------------------------------------------------
MY 89...............................................  .......  .......  .......  .......  .......  .......  .......  .......  ..........         500,000
MY 90...............................................  .......  .......        1  .......  .......        2  .......  .......           3       2,500,000
MY 91...............................................  .......  .......        1        1        1  .......  .......  .......           3       2,867,000
MY 92...............................................  .......  .......  .......  .......  .......  .......  .......  .......  ..........       5,084,000
MY 93...............................................  .......  .......  .......  .......  .......  .......  .......  .......  ..........       7,597,000
MY 94...............................................  .......  .......  .......  .......  .......        2  .......  .......           2       9,886,000
MY 95...............................................  .......  .......  .......  .......  .......  .......  .......        1           1      13,686,000
MY 96...............................................  .......  .......  .......  .......  .......  .......  .......  .......  ..........      14,055,000
                                                     ---------------------------------------------------------------------------------------------------
    Total...........................................  .......  .......        2        1        1        4  .......        1           9      56,175,000
--------------------------------------------------------------------------------------------------------------------------------------------------------


                                                  Age of Drivers Fatally Injured in Air Bag Deployments                                                 
--------------------------------------------------------------------------------------------------------------------------------------------------------
                       <20                           20-29        30-39        40-49        50-59        60-69        70-79         >80         Total   
--------------------------------------------------------------------------------------------------------------------------------------------------------
1...............................................            1            4            4            2            1            6  ...........           19
--------------------------------------------------------------------------------------------------------------------------------------------------------


Type of Restraint Used by Drivers Fatally Injured in Air Bag Deployments
------------------------------------------------------------------------
                                                                 No. of 
                    Type of restraint used                       drivers
------------------------------------------------------------------------
None..........................................................        10
Belts misused.................................................         1
Lap and shoulder belt (Driver blacked out and slumped forward           
 at time of crash due to medical condition)...................         2
Lap and shoulder belt.........................................         4
Unknown.......................................................         2
                                                               ---------
      Total...................................................        19
------------------------------------------------------------------------

Comparison of Passenger and Driver Air Bag Fatalities
    Several comparisons need to be drawn between the trends and 
patterns of child fatalities and the apparent trends and patterns of 
driver fatalities. The annual number of child fatalities is clearly 
growing steadily as the number of deployments increases. The annual 
number of adult fatalities does not appear to be growing. If anything, 
it appears to be decreasing, based on currently identified fatalities. 
(See tables below.)
    Most child fatalities (24 of 32) have occurred in model year 1994 
and 1995 vehicles. In contrast, only 4 of the 19 driver fatalities have 
occurred in a vehicle manufactured after model year 1992. The absence 
of fatalities in recent model year vehicles appears even more 
pronounced in the case of women 5 feet 2 inches or shorter. Only one 
woman 5 feet 2 inches or shorter has died in a post model year 1992 
vehicle.\10\ Most fatalities of short-statured women occurred in model 
year 1990-1992 vehicles. (See tables below.)
---------------------------------------------------------------------------

    \10\ NHTSA is aware of a number of fatalities in Canada 
reportedly related to air bag deployment, but only two in recent 
times. One was a November 1996 crash in Canada in which a 5 foot 3 
inch belted female driver was fatally injured in a model year 1996 
Ford Ranger. In addition, there was a November 1996 crash in which a 
5 foot 2 inch belted female driver was fatally injured in a model 
year 1993 Lexus. These Canadian accidents are not included in the 
driver fatality figures cited in this notice. (Similarly, lives 
saved by air bags outside the United States are not included in the 
savings.)

[[Page 812]]



             Comparison of Driver and Child Air Bag-Related Fatalities by Calendar Year of Fatality             
----------------------------------------------------------------------------------------------------------------
                                  CY 89    CY 90    CY 91    CY 92    CY 93    CY 94    CY 95    CY 96    Total 
----------------------------------------------------------------------------------------------------------------
                                                     Drivers                                                    
                                                                                                                
----------------------------------------------------------------------------------------------------------------
Women (5'2'' or less)..........  .......        1        1        1        2        1        4  .......       10
Other adults...................  .......  .......        2        1        1        4  .......        1        9
                                --------------------------------------------------------------------------------
      Total....................  .......        1        3        2        3        5        4        1       19
                                                                                                                
----------------------------------------------------------------------------------------------------------------
                                                    Children                                                    
                                                                                                                
----------------------------------------------------------------------------------------------------------------
Children (non-infant)..........  .......  .......  .......  .......        1        5        5       12       23
Infants........................  .......  .......  .......  .......  .......  .......        3        6        9
                                --------------------------------------------------------------------------------
      Total....................  .......  .......  .......  .......        1        5        8       18       32
----------------------------------------------------------------------------------------------------------------


               Comparison of Driver and Child Air Bag-Related Fatalities by Model Year of Fatality              
----------------------------------------------------------------------------------------------------------------
                                  MY 89    MY 90    MY 91    MY 92    MY 93    MY 94    MY 95    MY 96    Total 
----------------------------------------------------------------------------------------------------------------
                                                     Drivers                                                    
                                                                                                                
----------------------------------------------------------------------------------------------------------------
Women (5'2'' or less)..........        1        3        3        2  .......        1  .......  .......       10
Other adults...................  .......        3        3  .......  .......        2        1  .......        9
                                --------------------------------------------------------------------------------
      Total....................        1        6        6        2  .......        3        1  .......       19
                                                                                                                
----------------------------------------------------------------------------------------------------------------
                                                    Children                                                    
                                                                                                                
----------------------------------------------------------------------------------------------------------------
Non-infant Children............  .......  .......  .......  .......        3        5       11        4       23
Infants........................  .......  .......  .......  .......  .......        2        6        1        9
                                --------------------------------------------------------------------------------
      Total....................  .......  .......  .......  .......        3        7       17        5       32
----------------------------------------------------------------------------------------------------------------

Potential Number of Persons Saved Versus the Potential Number Fatally 
Injured by Current Air Bags
    The dilemma faced by NHTSA, and ultimately the public, is how to 
address the problem of low speed fatalities from air bags while 
preserving their substantial life-saving benefits. Based on analyses of 
real world data, NHTSA estimates that if all passenger cars and light 
trucks on the road today had current air bags, there would be more than 
3,000 lives saved each year, as compared to a no-air-bag fleet 
(assuming current belt use rates). More than two-thirds of the persons 
saved would be persons not using any type of safety belt.
    On the driver side, 616 belted drivers and 1,686 unbelted drivers 
would be saved, for a total of 2,302 lives saved. This is a net figure, 
i.e., it accounts for the possibility of 25 drivers being fatally 
injured annually by an air bag. Given that the average annual rate of 
driver fatalities for the last five years appears to be three, and that 
the annual rate does not appear to be increasing, the projected figure 
of 25 may be somewhat overstated.
    The potential number of lives saved by passenger air bags is much 
smaller than driver air bags primarily because the passenger seat is 
occupied much less frequently than the driver seat. If all passenger 
cars and light trucks had current passenger air bags, the agency 
estimates that 223 belted and 491 unbelted passengers aged 13 and above 
would be saved annually, for a total of 714 lives.
    However, this figure of 714 would be partially offset by air bag-
related fatalities involving children 12 and under. If current rates of 
child fatalities were experienced in an all-air-bag fleet, 128 children 
would be fatally injured by air bags annually, again assuming no 
technological improvements, changes to air bags, or behavioral changes 
by vehicle operators (e.g., ensuring that any children placed in the 
front seat properly use occupant restraints or, preferably, placing 
children in the rear seat). The figure of 128 includes 90 forward-
facing children, most of whom would be unbelted, and 38 infants in 
rear-facing child restraints.
    NHTSA emphasizes that this and the other rulemaking proceedings and 
related efforts are intended to ensure that risks of adverse side 
effects of air bags are reduced so that these theoretically projected 
air bag fatalities do not materialize, while the potential benefits of 
air bags are retained, to the maximum extent possible. Thus, the agency 
anticipates, e.g., that these other actions will result in proper use 
of restraints by increased numbers of people and that the number of 
children fatally injured would not be so high as 128. However, the 
agency does not have a basis for estimating the exact effect. Further, 
NHTSA recognizes that to the extent that one countermeasure is 
effective, the potential benefits of another countermeasure could be 
reduced. The Preliminary Regulatory Evaluation (PRE) for this 
rulemaking gives an illustrative example of the effect that labeling 
could have in reducing the benefits of depowering if the labeling were 
10 percent effective in inducing more parents to place their young 
children in the rear seat. (See page IV-54.) Likewise, a countermeasure 
may reduce the potential disbenefits of another countermeasure. To the 
extent that belt use is increased, the potential disbenefits of 
depowering for unbelted occupants would be reduced. NHTSA solicits 
suggestions for how it can attempt to quantify the interaction between 
its various initiatives for

[[Page 813]]

increasing belt use and decreasing the adverse side effects of air 
bags.

Projected Annual Lives Saved by and Fatalities Due to Air Bags 
11

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

    \11\ This projection is based on the assumption that all 
passenger cars and light trucks on the road have driver and 
passenger air bags. It does not take into consideration the impact 
of this proposal or any of the other agency actions described in the 
Overview and Summary section above.

                     Passenger Cars and Light Trucks                    
------------------------------------------------------------------------
                                                  Right front           
                                        Drivers    passengers    Total  
------------------------------------------------------------------------
Lives Saved..........................      2,327          714      3,041
Fatalities...........................         25          128        153
------------------------------------------------------------------------

III. Search for Solutions

    Over the last five years, NHTSA has taken a variety of steps to 
alert the public to the dangers posed by air bags to children and to 
explore measures for reducing and even eliminating those dangers. The 
steps taken in 1991-1995 were recounted in an NPRM published by the 
agency on August 6, 1996. 61 Fed. Reg. 40784.
    In the August 1996 NPRM, the agency proposed several amendments to 
Standard No. 208, Occupant Crash Protection, and Standard No. 213, 
Child Restraint Systems, to reduce the adverse effects of air bags, 
especially those on children. The agency explained that eventually, 
either through market forces or government regulation, it expects 
``smart'' passenger air bags to be installed in passenger cars and 
light trucks to mitigate these adverse effects. NHTSA indicated that, 
for purposes of the NPRM, it considered smart passenger air bags to 
include any system that automatically prevents an air bag from injuring 
the two groups of children that experience has shown to be at special 
risk from air bags: infants in rear-facing child seats, and children 
who are out-of-position (because they are unbelted or improperly 
belted) when the air bag deploys.
    NHTSA proposed that vehicles lacking smart passenger air bags would 
be required to have new, attention-getting warning labels and permitted 
to have a manual cutoff switch for the passenger air bag. By limiting 
the labeling requirement to vehicles without smart passenger air bags, 
NHTSA hoped to encourage the introduction of the next generation of air 
bags as soon as possible. NHTSA proposed to define smart air bags 
broadly to give manufacturers flexibility in making design choices. The 
agency requested comments concerning whether it should require 
installation of smart air bags and, if so, on what date such a 
requirement should become effective. NHTSA also requested comments on 
whether it should, as an alternative, set a time limit on the provision 
permitting manual cutoff switches for passenger air bags in order to 
assure the timely introduction of smart passenger air bags. Finally, 
the agency proposed to require rear-facing child seats to bear new, 
enhanced warning labels. In a section in the August 1996 NPRM titled 
``Future Agency Considerations,'' the agency also provided a discussion 
of possible technological changes to address the forcefulness of air 
bag deployment, ongoing agency efforts to evaluate the effects of such 
changes, and possible future agency regulatory actions.

C. Recent Petitions for Rulemaking

    Two weeks before the agency published its NPRM, the Parents' 
Coalition for Air Bag Warnings submitted a petition requesting the 
agency to commence a rulemaking proceeding to require that the 
following warning label be placed on dashboard of vehicles with 
passenger air bags:

    ``WARNING: DO NOT SEAT CHILDREN IN THE FRONT PASSENGER SEAT. AIR 
BAG DEPLOYMENT CAN CAUSE SERIOUS INJURY OR DEATH TO CHILDREN.''

    After the agency's publication of the August 1996 NPRM, the 
American Automobile Manufacturers Association (AAMA) submitted a 
petition for rulemaking requesting that NHTSA immediately announce, by 
means of a ``direct final rule,'' an amendment to Standard No. 208 to 
replace the current 30 mph unrestrained dummy barrier crash test 
requirement with a sled test protocol incorporating a 143 millisecond 
standardized crash pulse. The petitioner contended that the standard's 
current requirement ``directly dictates the level of the air bag's 
inflator power and it is the level of inflator power that unnecessarily 
increases the risk of injury to vehicle occupants during air bag 
deployment.'' AAMA also requested that the agency separately issue a 
notice of proposed rulemaking to propose requirements to improve the 
safety of drivers and passengers who are extremely close to the air bag 
at the time of deployment, based on the latest International Standards 
Organization (ISO) test practices. AAMA recommended the use of the 
Hybrid III small female dummy in the driver position and appropriate 
child dummy in the passenger position.
    On September 1, 1996, Ms. Anita Glass Lindsey petitioned the agency 
to commence rulemaking to specify the use of a test dummy representing 
a 5th percentile female 12 in testing the performance of safety 
belts and air bags. Currently, Standard No. 208 specifies the use of 
only a 50th percentile male test dummy. 13
---------------------------------------------------------------------------

    \12\ A 5th percentile Hybrid III dummy has a standing height of 
5 feet and a weight of 110 pounds.
    \13\ A 50th percentile Hybrid III dummy has a standing height of 
5 feet, 8 inches and a weight of 172 pounds.
---------------------------------------------------------------------------

    On September 17, 1996, the National Transportation Safety Board 
(NTSB) issued a number of safety recommendations to NHTSA for reducing 
the problem of child fatalities caused by air bags. These 
recommendations are as follows:
    1. Immediately evaluate passenger air bags based on all available 
sources, including NHTSA's recent crash testing, and then publicize the 
findings and modify performance and testing requirements, as 
appropriate, based on the findings of the evaluation.
    2. Immediately revise Federal Motor Vehicle Safety Standard 208, 
Occupant Crash Protection, to establish performance requirements for 
passenger air bags based on testing procedures that reflect actual 
accident environments, including pre-impact braking, out-of-position 
child occupants (belted and unbelted), properly positioned belted child 
occupants, and with the seat track in the forward-most position.
    3. Evaluate the effect of higher deployment thresholds for 
passenger air bags in combination with the recommended changes in air 
bag performance certification testing, and

[[Page 814]]

then modify the deployment thresholds based on the findings of the 
evaluation.
    4. Establish a timetable to implement intelligent air bag 
technology that will moderate or prevent the air bag from deployment if 
full deployment would pose an injury hazard to a belted or unbelted 
occupant in the right front seating position, such as a child who is 
seated too close to the instrument panel, a child who moves forward 
because of pre-impact braking, or a child who is restrained in a rear-
facing child restraint system.
    5. Determine the feasibility of applying technical solutions to 
vehicles not covered by NHTSA's proposed rulemaking of August 1, 1996, 
to prevent air bag-induced injuries to children in the passenger 
position.
    On November 8, 1996, the Center for Auto Safety (CFAS) petitioned 
the agency to amend Standard No. 208 to specify that a vehicle's air 
bags must not deploy in a crash if the vehicle's change of velocity is 
less than 12 mph. CFAS noted that many of the crashes resulting in air 
bag fatalities, especially those of children, involved very low changes 
in vehicle velocity. CFAS also petitioned the agency to institute 
investigations of several vehicle models for alleged defects related to 
air bag deployment.
    On November 13, 1996, the AAMA submitted a letter that modified the 
proposal in its August 1996 petition for rulemaking. In place of the 
143 millisecond standardized crash pulse, AAMA requested a sled test 
protocol incorporating a 125 millisecond standardized crash pulse.
    Finally, on November 20, 1996, CFAS and Public Citizen petitioned 
the agency to begin rulemaking to require dual inflation air bags. 
These bags would inflate more slowly, and thus less aggressively, than 
current air bags in low-speed crashes. In higher-speed crashes, they 
would inflate at the same rate as current air bags. The petitioners 
assert that their proposal is the best solution in the near future and 
is superior to depowering, since depowering involves ``some trade-off 
in safety protection and will not add significant protection for 
unrestrained children.''

IV. Overview of Comprehensive NHTSA Plan for Addressing Problem

    NHTSA is implementing a comprehensive plan of rulemaking and other 
actions (e.g., primary enforcement of State safety belt use laws) 
addressing the adverse effects of air bags. As part of that plan, NHTSA 
is issuing three separate, but related, notices today. Each notice is 
intended to ensure that some or all of the risks are reduced, and 
benefits retained, to the maximum extent possible. They provide 
immediate and/or interim solutions to the problem. A later notice, a 
proposal to require smart air bags, would provide a permanent solution.
    In this notice, NHTSA is proposing to temporarily amend the 
agency's occupant crash protection standard to help reduce the 
fatalities and injuries that current air bags are causing in relatively 
low speed crashes to small, but growing numbers of children, and 
occasionally to adults. Based on agency research and analysis regarding 
the optimal range of air bag depowering, the agency has tentatively 
concluded that an average depowering of 20 to 35 percent would reduce 
the risk of fatalities in low speed crashes, while substantially 
preserving the life-saving capabilities of air bags in higher speed 
crashes.
    The agency is considering the adoption of either, or both, of two 
different approaches that would permit or facilitate an approximate 20 
to 35 percent average depowering of current air bags. One approach 
would be to temporarily reduce the stringency of the chest acceleration 
requirement that an unbelted dummy must meet in a crash test at speeds 
up to 30 mph. The other approach would be to temporarily adopt the 
AAMA's modified proposal for a sled test protocol incorporating a 125 
millisecond standardized crash pulse.
    NHTSA is seeking comments and information concerning the relative 
desirability of these two approaches, including supporting data from 
industry with respect to the sled test. It is also requesting comments 
on the appropriate duration of such a temporary amendment. NHTSA 
anticipates that it would remain in effect for both the passenger and 
driver seating positions until smart air bags are installed pursuant to 
a mandated phase-in schedule, which will be the subject of a separate 
rulemaking proceeding. Finally, comments are sought on whether the same 
or different requirements should apply to the passenger and driver 
positions.
    The other rulemaking actions addressing the adverse side effects of 
air bags are as follows:
     Based on the August 1996 NPRM, the agency issued on 
November 22, 1996, a final rule amending Standards No. 208 and No. 213 
to require improved labeling on new vehicles and child restraints to 
better ensure that drivers and other occupants are aware of the dangers 
posed by passenger air bags to children. The labeling places particular 
emphasis on placing rear-facing infant restraints in the rear seats of 
vehicles with operational passenger air bags. 61 FR 60206; November 27, 
1996. The new labels are required on vehicles not equipped with smart 
passenger air bags beginning February 25, 1997, and on child restraints 
beginning May 27, 1997.
     Based on the same NPRM, the agency is issuing a final rule 
extending until September 1, 2000, a provision in Standard No. 208 
permitting vehicle manufacturers to offer manual cutoff switches for 
the passenger air bag for new vehicles without rear seats or with rear 
seats that are too small to accommodate rear-facing infant restraints.
     The agency also is issuing an NPRM proposing to permit 
motor vehicle dealers and repair businesses to deactivate, upon the 
request of consumers, driver and passenger air bags that do not meet 
the agency's criteria for smart air bags. Final action is expected in 
early 1997.
     In addition to these actions, NHTSA will issue a separate 
supplemental NPRM (SNPRM) to require a phasing-in of smart air bags, 
beginning on September 1, 1998, and to establish performance 
requirements for those air bags. The proposal will be issued in early 
1997.
    The next two tables summarize the rulemaking actions included in 
the agency's comprehensive program to address these air bag problems:

[[Page 815]]



                         Actions Addressing Problems Associated With Passenger Air Bags                         
----------------------------------------------------------------------------------------------------------------
                                                        Vehicles produced in next         Vehicles produced     
                              Existing vehicles            several model years               thereafter         
----------------------------------------------------------------------------------------------------------------
Passenger air bags....  Labels. New, attention-       Labels. Final rule requiring  Smart air bags. NPRM        
                         getting labels focusing on    new, attention-getting        proposing to phase in      
                         dangers of air bags to        labels focusing on dangers    requirement for smart air  
                         children, to be mailed by     of air bags to children, in   bags.                      
                         vehicle manufacturers to      vehicles whose passenger                                 
                         owners of existing air bag    air bag doesn't qualify as                               
                         vehicles.                     a smart air bag, and on                                  
                                                       child seats.                                             
                        Deactivation. Proposal to     Cutoff switches. Final rule                               
                         allow deactivation of         extending until Sept. 1,                                 
                         passenger air bag that        2000, provision allowing                                 
                         doesn't have cutoff switch    cutoff switch for vehicles                               
                         and doesn't qualify as a      (a) which lack a back seat                               
                         smart air bag.                that can accommodate rear-                               
                                                       facing infant seats, and                                 
                                                       (b) whose passenger air bag                              
                                                       doesn't qualify as a smart                               
                                                       air bag.                                                 
                                                      Deactivation. Proposal to                                 
                                                       allow deactivation of                                    
                                                       passenger air bag that                                   
                                                       doesn't have cutoff switch                               
                                                       and doesn't qualify as a                                 
                                                       smart air bag.                                           
                                                      Depowering. Proposal to                                   
                                                       temporarily allow                                        
                                                       depowering of passenger air                              
                                                       bags that don't qualify as                               
                                                       smart air bags.                                          
Driver air bags.......  Labeling. New, attention-     Labeling. Final rule          Smart air bags. NPRM        
                         getting labels urging all     requiring new labels urging   proposing to phase in      
                         occupants to use their        all occupants to use their    requirement for smart air  
                         safety belts and sit as far   safety belts and sit as far   bags.                      
                         back as possible to be        back as possible.                                        
                         mailed by vehicle                                                                      
                         manufacturers to owners of                                                             
                         existing air bag vehicles.                                                             
                        Deactivation. Proposal to     Deactivation. Proposal to                                 
                         allow deactivation of         allow deactivation of                                    
                         driver air bags.              driver air bags that don't                               
                                                       qualify as smart air bags.                               
                                                      Depowering. Proposal to                                   
                                                       temporarily allow                                        
                                                       depowering of driver air                                 
                                                       bags that don't qualify as                               
                                                       smart air bags.                                          
----------------------------------------------------------------------------------------------------------------

    In addition to these actions, the agency is participating with 
automobile manufacturers, air bag suppliers, insurance companies and 
safety organizations in a coalition effort to address the adverse 
effects of air bags by increasing the use of safety belts and child 
seats. Substantial benefits could be obtained from achieving higher 
safety belt use rates. If the safety belt use rate were 75 percent in 
potentially fatal crashes instead of the current level of 52.6 percent, 
an additional 4,000 lives would be saved annually.
    The coalition has a three-point program that seeks to educate the 
public about safety belt and child seat use, work with state and local 
officials to improve enforcement of safety belt and child seat use laws 
and seek the enactment of ``primary'' safety belt use laws. In States 
with ``secondary'' safety belt use laws, law enforcement officials are 
hampered in their ability to enforce the requirement to use safety 
belts because their inability to stop and ticket motorists for the sole 
reason of the motorists' failure to use their safety belts. A motorist 
may be ticketed by an official for such failure only if the official 
has a separate basis for stopping the motorist, such as the violation 
of a separate traffic law.
    A 1995 NHTSA analysis of FARS data on restraint use among fatally 
injured motor vehicle occupants from 1983 to 1994 indicates that 
primary enforcement is the most important aspect of a safety belt use 
law affecting the rate of safety belt use. For virtually all states 
with a primary enforcement law, statistically significant increases 
associated with the presence of such a law were detected using several 
different methods. The analysis suggests that the increase in use rates 
attributable to the enactment of a use law can be estimated to be (on 
the average) at least 25 percentage points, while the additional 
increase attributable to primary enforcement of the law is at least 15 
additional percentage points. These increases in safety belt use 
translate into an estimated 12.6 percent decrease in fatalities in a 
state that enacts a safety belt use law, and an additional 5.9 percent 
decline in fatalities in a state that authorizes primary enforcement of 
the law.
    State data support these findings. On average, states with a 
primary safety belt law have usage rates that are 10-15 percentage 
points higher than states with secondary laws. In California and 
Louisiana, states which recently upgraded their laws to allow for 
primary enforcement, safety belt usage increased by 13 and 17 
percentage points, respectively.

V. Depowering Air Bags

A. Results of NHTSA Test Program

    To determine whether current air bags can be depowered to a degree 
that makes a significant contribution to reducing the risk of serious 
or fatal injury to occupants, especially children, without substantial 
loss of protection for teenagers and adults, the agency initiated the 
research testing and analysis program discussed in the August 1996 
NPRM. NHTSA explained:
    The agency has initiated a research testing and analysis program * 
* * at the Vehicle Research and Test Center, the agency's in-house 
laboratory in Ohio. The program's objectives are to:
     Assess the performance of air bag systems in current 
production vehicles in particular crash conditions, including the 
effects on out-of-position children.
     Assess the level of improvement possible in out-of-
position performance from changes to existing air bag components, 
including downloaded air bags, as well as newly developed pre-
production systems.
     Provide visibility for air bag-related technology, thus 
promoting the rapid adoption of newer technologies that will

[[Page 816]]

help solve the out-of-position occupant injury problem.
    The immediate focus of the program is on the passenger out-of-
position problem as related to children. Several vehicle models have 
been selected based upon field accident investigations and air bag 
design characteristics. Both domestic and foreign vehicles are included 
in the selection. The test conditions include four different child 
positions similar to those recommended by ISO [International Standards 
Organization], and represent worst case occurrences. These tests will 
provide ``baseline'' performance of air bag systems when a child is an 
out-of-position occupant.
    NHTSA is inviting vehicle manufacturers and air bag and component 
suppliers to provide state-of-the-art air bag systems. Systems that 
show significant improvements over baseline performance for out-of-
position children will also be tested with adult-sized dummies in full-
scale crash conditions required in Federal standards.
    The test program will also address other aspects of air bag safety 
following the out-of-position child study. These include out-of-
position driver tests, vehicle crash sensor testing, and testing of 
advanced air bag systems. The out-of-position driver testing will focus 
on small-sized female occupants who are sometimes injured due to the 
close proximity to the steering-wheel air bag system. Testing will 
continue into fiscal year 1997.
(61 FR 40784, at 40799; August 6, 1996.)
    NHTSA has now tested the depowered air bags solicited from the 
vehicle manufacturers. The air bags had been depowered through the 
removal of certain amounts of propellant. While some of the air bags 
were depowered up to 60 percent, most of them were depowered an average 
of approximately 20 to 35 percent. However, their design (e.g., folding 
patterns and venting) had not been optimized for the reduced levels of 
power. As noted below, the agency believes optimization of the tested 
air bags would have significantly enhanced their performance.
    NHTSA tested baseline air bags (i.e., air bags of current design) 
and depowered air bags on the passenger side in three different 
vehicles, and on the driver side in one vehicle.14 NHTSA conducted 
these tests using modified versions of recommended test procedures 
formally adopted and issued in early 1996 by the ISO for evaluating 
child restraint system interactions (ISO TR 14645) and out-of-position 
vehicle occupant interactions (ISO TR 10982) with deploying air bags. 
For the passenger air bags, the agency conducted various tests using 
out-of-position three-year-old and six-year-old child dummies and 
normally-positioned, belted and unbelted 50th percentile male 
dummies.15 For the driver air bags, the agency conducted various 
tests using out-of-position 5th percentile female dummies and normally-
positioned, belted and unbelted 50th percentile male dummies. The 
agency also used computer-assisted mathematical modeling in an attempt 
to assess the effects of depowering on the forces experienced by 
occupants in air bag deployments.
---------------------------------------------------------------------------

    \14\ The passenger air bag testing began in February 1996. The 
testing of passenger air bags to estimate the effects of depowering 
was completed in September. However, the testing of advanced 
passenger air bag designs and test conditions continues. Testing of 
driver air bags was conducted from May to September of this year. 
More tests of driver air bags are planned for the future.
    \15\ NHTSA did not conduct tests to determine the effects of the 
depowered air bags on an infant dummy (i.e., nine-month-old dummy) 
in rear- facing child restraints because the design of the depowered 
bags would have precluded obtaining meaningful measurements of those 
effects. Since all of the vehicles had top-mounted air bags (i.e., 
on top of the dashboard), the air bags would have tended to deploy 
above the child restraints instead of directly impacting them. This 
assessment appears consistent with the near total absence of top-
mounted air bags from the list of air bags involved in the fatal 
injury of infants. None of the nine air bags was mid-mounted.
---------------------------------------------------------------------------

    The results of the agency's analysis of this testing, as well as 
other available information, are included in the PRE. Portions of the 
PRE are summarized below.

B. Effects of Depowering and Optimizing

    Overview. The agency's testing and other available information 
16 indicated that depowering by an average of 20 to 35 percent 
substantially reduced injury measures for persons close to the air bag, 
especially out-of-position children, while producing only small 
increases in injury measures for adult dummies. In the agency's 
testing, depowering more than 35 percent resulted in more substantial 
increases in adult dummy injury measures with a large additional 
reduction in out-of-position child dummy injury measures for only the 
more aggressive air bags. Thus, it appears that depowering at levels 
more than an average of 35 percent could result in losing a significant 
portion of the benefits being provided by air bags without a 
commensurate reduction in child injury risk. (However, it is possible 
that some of today's air bags are so aggressive that they could, if 
optimized, be depowered by more than 35 percent without substantial 
losses in adult benefits.)
---------------------------------------------------------------------------

    \16\ Among the other items of information were the results of 
testing performed by AAMA using out-of-position dummies representing 
a six-year-old child, a 5th percentile female and a 50th percentile 
male.
---------------------------------------------------------------------------

    The reductions in injury measures achieved by depowering an average 
of 20-35 percent would contribute significantly to solving the problem 
created by overly aggressive air bags.17 While this average level 
of depowering would not eliminate all of the risk of serious injury to 
all persons currently at risk, it would eliminate much of the risk. The 
agency's other rulemaking actions would reduce the residual risk.
---------------------------------------------------------------------------

    \17\ The actual amount that the air bag in each specific vehicle 
model would need to be depowered to achieve these benefits would 
vary depending on the aggressivity of its air bag system. The least 
aggressive air bags might need less than 20 to 35 percent 
depowering, while the most aggressive ones might need more, as much 
as 60 percent.
---------------------------------------------------------------------------

     As noted above, the tested air bags were depowered, but not 
optimized. Had they been optimized, the injury measures for belted 
passengers would likely have decreased even more and those for belted 
drivers would likely have improved. Thus, they would have offered 
increased safety for belted occupants.18
---------------------------------------------------------------------------

    \18\ The agency's belief that depowered air bags will provide 
increased benefits to real world occupants compared to current air 
bags is based in part on actual crash data regarding the performance 
of air bags in an Australian passenger car, the Holden Commodore, 
which is described below.
---------------------------------------------------------------------------

Summary of Effects of Depowering on Air Bag-Related Fatalities for 
Particular At-Risk Occupant Groups
    The ability of depowering to prevent air bag fatalities to 
occupants would vary depending on a number of factors, especially the 
location and belt use of the occupant. As shown in testing by the 
agency of passenger air bags, the forces exerted by a deploying air bag 
generally decrease as a function of increasing distance from the air 
bag module. Although the surface of an expanding air bag in its initial 
moments of inflation is potentially lethal, it rapidly changes within 
inches into an injury-preventing and life-saving surface as it inflates 
and moves away from its storage location. Thus, the farther away an 
occupant is from an air bag as it starts to inflate, the better off 
that occupant will be. While this is true for depowered as well as 
current air bags, depowering can significantly reduce the size of the 
zone within which serious injury is possible or likely.
    Passengers. The at-risk groups are infants and young children. 
Properly belted, forward-facing children who are on a vehicle seat 
moved all the way back, should be at essentially no risk from a 
deploying, depowered air bag,

[[Page 817]]

even if they are leaning forward while belted. Moderately out-of 
position, forward-facing children would receive substantial benefits. 
Severely out-of-position, completely unbelted forward-facing children 
would receive some benefits. Given their proximity to the air bag, 
infants in rear-facing child restraints would likely receive only 
small, unquantifiable benefits from depowered air bags.19
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    \19\ As the agency has emphasized in numerous contexts, infants 
in rear-facing child restraints should NEVER be placed in the front 
seat of a vehicle with an operational passenger air bag.
---------------------------------------------------------------------------

    Drivers. To the extent that there is an at-risk group, it is short-
statured women. Short, belted drivers on a vehicle seat moved as far 
back as their stature permits would receive substantial benefits, 
particularly with respect to neck injuries. They are not likely to move 
as far forward as unbelted drivers during pre-crash braking and during 
the initial stages of a crash. Benefits for unbelted drivers on a 
vehicle seat moved all the way forward would depend on the drivers' 
proximity to the air bag at the time of deployment. If they are at 
least two or three inches away at the time of deployment, they should 
receive some benefits from depowering with respect to chest and head 
injuries. Depowering should help all drivers with respect to arm 
injuries.
    Overall Effects of Depowering. The PRE estimates the potential 
overall effects of depowering on all forward-facing children, teenage 
and adult occupants under the two alternative proposals, the 80 g 
alternative and the generic sled test alternative. Both proposals would 
produce a mixture of benefits and disbenefits, with the benefits 
primarily accruing to children and belted teenage and adult occupants, 
and the disbenefits primarily accruing to unbelted teenage and adult 
occupants.
    The magnitude of the benefits and disbenefits are estimated in the 
PRE by two different methods. Method One includes only fatalities, 
while Method Two includes fatalities and serious injuries. The results 
of Method One, which produces slightly smaller upper end values for 
lives saved and for foregone savings of lives, are discussed below.
1. Passenger Air Bags
    Child Passengers. Older, Forward-Facing Children. Depowering could 
prevent a significant number of the 90 annual fatalities projected 
above for forward-facing children 20 in an all air bag fleet for 
passenger cars and LTV's. The PRE estimates that 39 of the projected 90 
fatalities could be prevented by depowering air bags by an average of 
20 to 35 percent. This includes all of the lap and shoulder belted 
children who might otherwise be fatally injured and most of the 
moderately out-of-position children.21 With the additional 
depowering possible under the generic sled alternative,22 up to 83 
of the projected 90 fatalities could be prevented since more of the 
severely out-of-position children could be benefited. Thus, depowering 
would make it safe, from the standpoint of the air bag, to place a 
child in the front seat when necessary, assuming that the child was 
properly restrained in a vehicle seat that was moved all the way back. 
The agency emphasizes that, even in the absence of an air bag, the rear 
seat is a significantly safer place for children to ride than the front 
seat.
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    \20\ As noted above, the age range of the forward-facing 
children fatally injured during air bag deployments is one to nine 
years old.
    \21\ These estimated savings are based on the significant 
reductions in neck injury criteria values observed in all three 
tested vehicles. These values are the most important ones for 
estimating fatality risk, since neck injury has been the typical 
fatal injury mechanism for these children.
    \22\ As reflected below in the discussion of the alternative 
proposals, it is assumed in the PRE that the depowering of any air 
bags more than 35 percent is achievable only under the second 
alternative proposal (i.e., AAMA's generic sled pulse) since it 
appears that HIC or other injury criteria could not be met under the 
first alternative proposal (80 g limit on chest g's in the unbelted 
30 mph test) with air bag systems depowered significantly above 35 
percent.
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    Rear-Facing Children (Infants). Based on HIC reductions achieved in 
testing the effects of depowered air bags on three- and six-year-old 
dummies, the agency believes that depowering could prevent the death of 
some of the 38 projected fatalities of infants. However, for reasons 
explained below, the agency cannot quantify those savings.
    As noted above, the agency did not perform any testing of depowered 
air bags with infants in rear-facing infant seats. Thus, the agency 
does not have any baseline versus depowered air bag data for rear-
facing child restraints to estimate the potential benefits of 
depowering. However, HIC data from the testing of severely out-of-
position three- and six-year-old children indicate that HIC was 
substantially reduced by depowering, but not typically below the 
assumed infant injury reference value of 500 HIC. HIC data are relevant 
because the primary cause of rear-facing infant fatalities in air bag 
deployments has been skull fractures. Since it is not possible at this 
time to make appropriate adjustments to reflect greater susceptibility 
of infants to fatal head injury, the HIC data for dummies representing 
older children could not be used to estimate potential benefits of 
depowering for infants. The agency has not made a specific, quantified 
estimate because of its roughness and therefore its questionable value.
    Teenage and Adult Passengers. Depowering air bags to an average of 
20 to 35 percent would likely benefit belted teenage and adult 
passengers on balance, but could necessitate foregoing the opportunity 
to save some unbelted teenage and adult passengers.23 These 
estimates are based on chest g measures because, as noted in the PRE, 
chest g's are the most important measure for assessing the effects on 
teenagers and adults, since chest g's appear to have a stronger 
relationship to fatality risk than HIC. Further, the HIC increases due 
to depowering in this range were not that significant.
---------------------------------------------------------------------------

    \23\ As noted below, the occupants can essentially eliminate the 
risk to them by the simple act of buckling their safety belts.
---------------------------------------------------------------------------

    Belted Teenage and Adult Passengers. The agency's PRE assumes a 2.4 
g decrease in chest g's for belted passengers under the 80 g 
alternative, using an air bag that had been depowered but not 
optimized. This assumption was based on test results showing a 2.4 g 
decrease in chest g's, although mathematical modeling predicted almost 
no change for belted passengers. Under the generic sled test 
alternative, a decrease of 1.9 chest g's is assumed, based on 
mathematical modeling. Both decreases would result in saving additional 
lives compared to current air bag designs.
    As noted above, NHTSA believes that a greater decrease in chest 
g's, and therefore a greater increase in life-saving potential, would 
have occurred had the air bags not only been depowered, but also 
optimized for the new power level. The depowered air bags tested by 
NHTSA were not optimized in ways that would likely have reduced the 
chest g's even more. For example, the air bags were not optimized with 
respect to their venting rates.
    The agency believes that it is unlikely that the vehicle 
manufacturers would depower their air bags without also optimizing 
them. NHTSA believes that the manufacturers would, out of reasonable 
prudence, do both.
    This is significant because real world data from Australia 
regarding the performance of depowered driver air bags optimized for 
belted occupants suggests that depowering and

[[Page 818]]

optimizing current U.S. air bags could significantly increase the 
effectiveness of air bags for belted occupants and lead to large 
savings of lives. Those data, drawn from crashes involving Holden 
passenger cars,24 indicate that air bags with lap/shoulder belts 
reduced AIS 2+ injuries to drivers by 39 percent compared to lap/
shoulder belts alone. By comparison, current U.S. air bags have an AIS 
2+ effectiveness of 22 percent when lap and shoulder belts are worn. 
According to the PRE:

    \24\ The Holden passenger cars have depowered air bags that have 
a ``no-fire'' threshold of 12.4 mph and an ``always-fire'' threshold 
of 17.4 mph. While thresholds vary for U.S. air bags, a typical one 
has a ``no-fire'' threshold of 9 mph and an ``always-fire'' 
threshold of 14 mph.
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    The air bag systems in the Commodore are designed to deploy as 
unaggressively as possible while still providing the necessary 
protection to occupants of different size, weight and sex who will 
be potentially involved in a variety of collisions. Great efforts 
have been taken in the development of the inflators and cushions to 
ensure they present as little risk as possible to occupants during 
inflation. Since the air bags have been designed to operate in 
conjunction with the safety belts, they are only required to 
decelerate the occupant's head and upper torso, as the primary load 
path is through the belts. This is fundamentally different from many 
other air bag designs, especially those used to protect unrestrained 
occupants. Systems optimized to protect unrestrained occupants 
typically utilize high-performance inflators in conjunction with 
cushions with low venting rates. This combination ensures that the 
air bags are sufficiently stiff to decelerate unbelted occupants.

(Page V-1)
    If such increased effectiveness could be obtained for belted 
passengers, it would offset a significant portion of the potential 
adverse impact of depowering estimated below on unbelted passengers. As 
discussed in the PRE, current NHTSA analyses indicate that air bags in 
this country are 8.5 percent effective in reducing belted fatalities. 
If the relationship in overall effectiveness of the Holden bag to the 
U.S. air bags for AIS 2+ injuries were the same for fatalities, the 
effectiveness of U.S. air bags for preventing fatalities to belted 
occupants could be as high as 15 percent. If depowering and optimizing 
U.S. air bags increased their effectiveness to that level, large 
savings in the lives of belted occupants could result.
    The agency seeks comments, on a model-by-model basis, if possible, 
from the vehicle manufacturers on what specific optimization measures 
they would adopt and on whether such optimization could be accomplished 
and incorporated in production air bags within the time frame projected 
by the vehicle industry for introduction of the depowered air bags. As 
noted below, AAMA projected that its members could begin introducing 
depowered air bags within 6-9 months and complete the process across 
their fleets within a year after those first introductions. NHTSA 
solicits comments as to what effect, if any, efforts to optimize these 
air bags prior to their introduction might have on the schedule for 
their introduction. Comment is also sought whether adoption of the sled 
test suggested by AAMA would enable vehicle manufacturers to accelerate 
the introduction of optimized and depowered air bags. The agency also 
requests comments on what effects, if any, the optimization of air bag 
performance for the benefit of belted occupants would have on air bag 
effectiveness for unbelted occupants. Finally, comment is sought on the 
Holden data and the reasonableness of the assumption in the PRE that 
effectiveness of U.S. air bags in reducing belted fatalities could be 
raised substantially in the next several years through depowering and 
optimizing.
    Unbelted Teenage and Adult Passengers. Depowering could necessitate 
foregoing the opportunity to save a significant number of unbelted 
teenagers and adults. The PRE estimates that, as a result of a 
significant increase in chest g's associated with depowering by an 
average of 20 to 35 percent under the 80 g alternative, there could be 
a reduction of between 86 and 280 unbelted passengers who would have 
otherwise been saved by current air bags. This reduction reflects an 
assumed average increase of 11 g's in the chest g's for unbelted 
passengers as a result of depowering, but not optimizing air bags. This 
assumption was based on limited test results showing an 11 g increase 
in chest g's at 30 mph. Mathematical modeling predicted a slightly 
lower increase. With greater depowering under the generic sled test 
alternative, it was assumed that chest g's would increase by 22 g's, 
based on sled tests and mathematical modeling. That increase would 
result in a potential loss of savings of 115 to 336 unbelted 
passengers.
    It should be noted, however, that AAMA does not anticipate such 
losses. AAMA provided an estimate of the effects of depowering, based 
on NASS data, a number of analytic assumptions, and sled/barrier test 
results. That organization estimates the potential savings of 30 to 200 
small adults per year due to increased effectiveness of passenger and 
driver air bags for those persons and the potential loss of up to eight 
large adults annually. The agency seeks comment from AAMA on how it 
calculated those figures.
    Further, to the extent that increased numbers of people use their 
safety belts, the potential losses in savings of unbelted passengers 
would not materialize. While increasing safety belt use would reduce 
the benefits of depowering, by reducing the size of some groups (i.e., 
unbelted children and drivers) vulnerable to air bag fatalities, there 
would be very large increases in the number of people saved by occupant 
restraints of one type or another. As noted above, if the safety belt 
use rate were 75 percent in potentially fatal crashes instead of the 
current level of 52.6 percent, an additional 4,000 lives would be saved 
annually. NHTSA plans to work vigorously with the States to increase 
safety belt use through public education and authorizing primary 
enforcement of safety belt use laws.
    Safety Tradeoffs. NHTSA has carefully considered the potential 
tradeoffs implicit in depowering passenger air bags. Given the wide 
range of the above estimates concerning unbelted passengers, the agency 
believes that the net effect of depowering on safety could be positive. 
However, even if the net effect were negative, the agency believes that 
the opportunity to save a significant number of children who would 
otherwise be fatally injured by air bags justifies foregoing the 
opportunity to save some unbelted passengers. There are several reasons 
for this policy choice.
    First, it is not acceptable that a safety device cause a 
significant number of fatalities in circumstances in which fatal or 
serious injuries would not otherwise occur. In making this statement, 
the agency draws a distinction between air bags which are fatally 
injuring young children in low speed crashes in which the other vehicle 
occupants are uninjured, and other safety devices which may on occasion 
unavoidably substitute one type of injury for another type that would 
occur in their absence (safety belts are a good example).25 Those 
fatalities are particularly unacceptable in light of the agency's 
analysis showing that depowering air bags can significantly reduce the 
number of children being fatally injured by air bags.
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    \25\ In severe collisions, safety belts can seriously bruise the 
chest of an occupant or even cause rib fractures. However, the 
restraining force of the belt would also likely prevent even more 
serious chest or head injury from the occupant's striking the 
interior components of the vehicle.
---------------------------------------------------------------------------

    Second, it is also particularly unacceptable that the vehicle 
occupants being fatally injured are young children, and that the number 
of those deaths is

[[Page 819]]

steadily growing. In confronting the possibility of inevitable short-
term safety tradeoffs between young children and unbelted occupants 
over 12 years of age, the agency believes that greater weight must be 
placed on protecting young children. NHTSA has always given a high 
priority to protecting children and accordingly has applied these 
different cost-benefit considerations to its rulemaking affecting 
children. The agency's activities related to school bus safety 
standards are an example of this policy.
    A major reason for giving priority to protecting young children is 
that they are less mature than teenagers and adults and thus less able 
to exercise independent judgment, assess the risks and take action to 
improve their safety. The young children are more dependent on the 
judgment and actions of other persons. The oldest of the 32 children 
who have been fatally injured by an air bag was nine years old, and 
most of the children have been much younger. Nineteen were four to 
seven years old and nine were infants. Conversely, the unbelted 
teenagers and adults who might not be saved as a result of depowering 
can take action on their own to protect themselves by simply buckling 
their safety belts as required by the laws of 49 States and the 
District of Columbia.
    Notwithstanding the justifications for making the safety tradeoffs, 
NHTSA is concerned about them. It is because of the possibility of 
disbenefits, especially for unbelted occupants, that the agency is 
proposing to make only a temporary change in Standard No. 208 to permit 
or facilitate the depowering of air bags. The agency will shortly issue 
a proposal to require a phase-in of smart air bags. Requiring smart air 
bags would not only enable the agency to make depowering a temporary 
measure, but would also ensure that the problem of adverse effects from 
air bags is fully addressed, and that air bags achieve their full 
safety potential for protecting a wide variety of vehicle occupants 
over an appropriate range of vehicle speeds.
2. Driver Air Bags
    Analysis of the net effect of depowering driver air bags is more 
difficult and therefore less precise largely because the agency has 
conducted fewer tests of depowered driver air bags and because the test 
results for the unbelted drivers are a mixture of small increases and 
decreases in chest g's. Nevertheless, the agency believes that 
depowering driver air bags would enhance safety. As noted above, belted 
short drivers who move their seat as far back as their stature permits, 
would benefit substantially from depowering. Belted drivers, in 
general, should benefit as well since depowering appears to allow a 
better ``tuning'' of the combined safety belt-air bag system for belted 
occupants. Unbelted, out-of-position short drivers could receive some 
benefit as well. As a result, there would be some reduction in the 
projected figure of 25 driver fatalities per year.
    Belted Drivers. Depowering alone increased the chest g's for belted 
drivers in NHTSA's vehicle testing. Although the tests showed a 7 g 
increase at 35 mpg, there appears to be no logical reason for such an 
increase. In the same test, chest g's decreased for the belted 
passenger dummy. Further, modeling suggested only a marginal increase 
of 2 g. The PRE assumes a 2 g increase for belted drivers under the 80 
g alternative. Under the generic sled test alternative, chest g's go up 
or down at different speeds with the net result that there would be no 
change in overall fatalities for depowered, but not optimized, air 
bags.
    As in the case of passenger air bags and belted passengers, the 
agency believes that the data concerning the air bags in the Australian 
Holden passenger car show that optimizing as well as depowering air 
driver bags would produce a more favorable result for belted drivers 
than the depowered air bags tested by NHTSA. Since most of the Holden 
data related to driver air bags instead of passenger air bags, the 
agency has good reason to be even more confident about the implications 
of the Holden data for belted drivers in this country. With 
optimization, the agency believes that, instead of an increase in chest 
g's under the 80 g alternative or no change under the generic sled test 
alternative, a decrease is likely. If depowering and optimizing U.S. 
driver air bags increased their effectiveness to as much as 15 percent, 
the savings would be 471 drivers.
    Unbelted Drivers. Depowering by an average of 20 to 35 percent 
under the 80 g alternative appears to slightly increase the chest g's 
of unbelted drivers. It is believed that the energy absorbing steering 
column is the reason that chest g's do not increase in proportion to 
the amount of depowering. In vehicle tests with depowered air bags, 
chest g's increased by 2 g at 30 mph, but decreased by almost 3 g's at 
35 mph. The results of modeling were mixed also, but consistent with 
the vehicle test results. Modeling predicted a slight increase at 30 
mph and decrease at 35 mph. Since there was an increase at some speeds, 
the PRE assumes a 2 g increase under the 80 g alternative. Based on 
that increase, the PRE estimates a possible loss in savings of 9 to 41 
unbelted drivers. Under the generic sled test alternative, the PRE 
assumed a 10 g increase based on modeling. That increase suggests a 
resulting loss of 221 to 650 unbelted drivers.
    As noted above, there is reason to believe that these losses might 
not occur. AAMA estimates the potential savings of 30 to 200 small 
adults per year due to increased effectiveness of passenger and driver 
air bags for those persons and the potential loss of up to eight large 
adults annually. Further, to the extent that increased numbers of 
people use their safety belts, the potential losses in savings of 
unbelted passengers would not materialize. NHTSA plans to work 
vigorously with the States to increase safety belt use through public 
education and authorizing primary enforcement of safety belt use laws.
    Arm Injuries. The agency believes that depowering would lead to a 
significant reduction in driver arm injuries associated with air bag 
deployments. Compared to MY 1994 vehicles, depowering air bags by an 
average of 20 to 30 percent could reduce AIS 2-3 arm injuries from 
25,006 to 16,254, a reduction of about 8,800 injuries.
    Safety Tradeoffs. NHTSA has carefully considered the potential 
tradeoffs implicit in depowering driver air bags. Despite the wide 
range of the above estimates concerning unbelted drivers, the agency 
believes that the net safety effect of depowering passenger air bags 
could be positive instead of negative. Even if the net effect were 
negative, the agency believes that the opportunity to avoid causing 
fatal injuries to some drivers justifies foregoing the opportunity to 
save more unbelted drivers. The reasons for this policy choice are 
similar to those for depowering passenger air bags.
    First, the principle of not affirmatively causing harm when harm 
would not otherwise occur applies to all vehicle occupants. While it is 
probably unavoidable that some safety devices may on occasion 
substitute one type of injury for another type that would occur in 
their absence, it is not acceptable that safety devices cause a 
significant number of fatalities in circumstances in which fatal or 
serious injury would not otherwise occur.
    Second, the drivers who might lose benefits as a result of 
depowering are unbelted drivers. They can protect themselves by taking 
the simple step of buckling their safety belts as required by the laws 
of 49 States and the District of Columbia.

[[Page 820]]

    Nevertheless, as noted above, due to the possibility of adverse 
safety tradeoffs, NHTSA is seeking to limit the duration of the 
tradeoffs by proposing to make only a temporary change in Standard No. 
208 to permit or facilitate the depowering of air bags. The agency's 
planned proposal to require smart air bags would not only enable the 
agency to make depowering a temporary measure should the adverse 
tradeoffs actually materialize, but would also ensure that the problem 
of adverse effects from air bags is fully addressed, and that air bags 
achieve their full safety potential.

C. Alternative Proposals

    The preceding sections of this notice discuss the benefits of 
depowering passenger and driver air bags by various amounts, and the 
net effects on safety. While the agency recognizes that depowering air 
bags may result in some adverse safety tradeoffs, primarily to unbelted 
teenage and adult occupants, it believes that depowering represents a 
desirable temporary means of addressing the problem of fatalities and 
injuries from air bags.
    Having tentatively decided that depowering of air bags is 
desirable, it is necessary for the agency to determine whether a 
regulatory change is needed to permit this action and, if so, what the 
most appropriate change would be.
    Manufacturers have asserted that a regulatory change is needed 
because if air bags were depowered to an appropriate extent, 
manufacturers would be unable to certify that all of their vehicles 
comply with Standard No. 208's unbelted test requirements.
    As discussed in the PRE, the agency's testing shows that an average 
20 to 35 percent depowering of passenger air bags would result in chest 
g's for some vehicles approaching or slightly exceeding Standard No. 
208's 60 g limit for the unbelted test. This indicates that a 
regulatory change would be needed to permit this level of depowering 
for these vehicles. The agency's limited data suggest that the 
standard's other requirements would not preclude this level of 
depowering, although the 1000 HIC limit would prevent significantly 
higher levels of depowering.
    NHTSA does not have data concerning whether a regulatory change 
would be needed to permit 20 to 35 percent depowering of driver air 
bags, but is requesting commenters to provide such data. As discussed 
in the PRE, when driver air bags depowered to that extent were tested 
by NHTSA at 30 mph, unbelted chest g's increased from 49 to 51. Ford 
modeling for driver air bags shows similar results, with chest g's 
rising by only 2 or 3 g's for belted and unbelted drivers. Available 
NHTSA modeling shows variable results (some chest g's going up and 
others down), but all were well within the standard at 30 mph. The 
agency believes that energy absorbing steering columns explain why the 
driver air bag can be depowered without significantly affecting chest 
g's. However, the agency conducted only limited testing and did not 
conduct any angle tests. The agency requests comments, including data, 
concerning how depowering driver air bags by various percentages would 
affect the manufacturers' ability to certify compliance with Standard 
No. 208.
    The agency is proposing the adoption of either, or both of two 
potential changes as alternative temporary amendments to Standard No. 
208: either increasing the current chest acceleration limit to 80 g's, 
or replacing the unbelted crash test requirement with a sled test 
protocol incorporating a standardized crash pulse. If the agency were 
to adopt both of these changes, a manufacturer could select either 
alternative at its option. However, a manufacturer could not mix the 
two options, i.e., the 80 g chest acceleration limit would not apply in 
the case of the generic sled test.
    A discussion of each of the two alternative approaches being 
proposed by the agency is presented in the next two sections.
1. Approach I--Temporary Change in Unbelted Chest Acceleration 
Requirement
    NHTSA believes that the simplest regulatory change would be to 
amend the requirement which appears to be the factor limiting the 
vehicle manufacturers' ability to depower current air bags by 20 to 35 
percent. This points to reducing the stringency of the unbelted chest 
acceleration requirement. The agency is proposing to increase the 
current limit from 60 g's to 80 g's. However, the agency is requesting 
comments on both higher and lower values, and could select a different 
value for the final rule.
    This alternative has other advantages in addition to its 
simplicity. Occupant protection would continue to be measured in full-
scale vehicle tests, protection in impacts at a range of angles would 
be ensured, and the other injury criteria would not change. The agency 
notes that recent biomechanical data generated for NHTSA suggests that, 
with respect to potential chest injuries, the human tolerance to 
acceleration is higher for air bags than for belts, because the air bag 
delivers a more broadly distributed, uniform loading to the chest than 
does a safety belt. Therefore, an 80 g requirement for occupants 
protected by air bags appears to be at least as protective as a 60 g 
requirement for belted occupants.
    The agency notes that amending the standard to allow chest 
accelerations of 80 g's does not mean that chest g measurements in 
crash tests would necessarily rise to that level. The agency's test 
data suggest that while a change to 80 g's would be sufficient to 
permit or facilitate 20 to 35 percent downloading, air bags with 
progressively higher levels of downloading (beyond 20 to 35 percent) 
are likely to exceed Standard No. 208's head injury criterion before 
they exceed the 80 g requirement.
    NHTSA also notes that the PRE's estimates of safety impacts for the 
80 g alternative do not assume an increase to 80 g's, or to any 
particular level below 80 g's. The estimates are instead based on the 
agency's analysis of the effects of depowering air bags by 20 to 35 
percent.
    The agency's analysis assumes, based on limited vehicle testing, 
that chest g's would rise by an average of approximately 11 g's for the 
unbelted 50th percentile male. Since compliance data show that chest 
g's for this test currently average about 43 g's, the assumed 11 g 
increase means that the average would increase to about 54 g's for the 
50th percentile male dummy.
    NHTSA intends for any regulatory change to Standard No. 208 to 
permit or facilitate quick depowering of air bags. In order to reduce 
the leadtime for depowered air bags, the agency is proposing, as part 
of its 80 g proposal, to establish a special two-year enforcement 
policy for Standard No. 208's unbelted test requirements.
    The agency recognizes that, under ordinary circumstances, 
manufacturers making air bag design changes typically conduct extensive 
testing to ensure that a vehicle will continue to meet the standard's 
performance requirements at any particular level. They do so despite 
the existence of various provisions of Standard No. 208 that provide 
that ``a vehicle shall not be deemed to be in noncompliance with this 
standard if its manufacturer establishes that it did not have reason to 
know in the exercise of due care that such vehicle is not in conformity 
with the requirement of this standard.'' See, e.g., S4.1.5.3.
    While NHTSA generally considers some degree of testing to be 
necessary to satisfy this ``due care'' requirement, under the proposed 
two-year policy, the agency would consider engineering analyses 
indicating that a vehicle will pass the unbelted test requirements with 
a depowered air bag as sufficient during that period to establish that 
the vehicle's

[[Page 821]]

manufacturer exercised due care to ensure that the vehicle conforms 
with the requirement, even in the absence of confirming crash testing. 
Of course, the agency would retain the right to enforce the 
requirements of the standard if the noncompliance was due to quality 
control deficiencies or other manufacturing problems. This policy would 
be reflected in an appendix to the standard.
2. Approach II--Temporary Replacement of Unbelted Crash Test 
Requirement With a Sled Test Protocol Incorporating a Standardized 
Crash Pulse
    In August 1996, AAMA submitted a petition for rulemaking 
requesting, among other things, an immediate amendment to the 
requirements for testing the ability of air bags to protect unbelted 
occupants. The current requirement measures occupant protection in a 
full scale crash test in which a vehicle, equipped with test dummies at 
the outside front seating positions, is crashed into a barrier. 
Specified injury criteria, measured on the test dummies, must be met in 
barrier crashes at speeds up to 30 mph, and a range of angles up to 30 
degrees off-center.
    AAMA requested that this crash test requirement be replaced with a 
sled test protocol. Under that protocol, all of a vehicle, or a portion 
of the vehicle representing the interior, would be mounted on a sled. 
The sled would be decelerated from 30 mph according to a standard 
formula, called a crash pulse. There would not be an angle test, only a 
direct frontal test.
    NHTSA notes that sled tests can be used by researchers to simulate 
what will happen to occupants in real world crashes. The crash pulse 
for a given sled test is a major determinant of the stringency of the 
test, and how representative the test is of how a particular vehicle 
will perform in particular kinds of real world crashes.
    To explain further, the term ``crash pulse'' is defined as the 
acceleration-time history of the occupant compartment of a vehicle 
during a crash. This is typically represented in terms of g's of 
acceleration plotted against time in milliseconds (1/1000 second). 
Generally speaking, the occupant undergoes greater forces due to 
secondary collisions with the vehicle interior and restraint systems if 
the crash pulse g's are higher at the peak, or the duration of the 
crash pulse is shorter, which would lead to higher overall average g 
levels.
    The crash pulse experienced by a particular vehicle will obviously 
differ substantially in different types of crashes, e.g., if the 
vehicle crashes into a rigid stone wall vs. a stack of hay. Similarly, 
vehicles with different designs typically experience substantially 
different crash pulses in the same kind of crash, depending on such 
things as the stiffness of the vehicle structure and amount of crush 
space. Large cars typically have relatively mild crash pulses, while 
small cars and utility vehicles typically have more severe crash 
pulses.
    Under AAMA's recommended amendment, the same crash pulse would be 
used for all vehicles. The petitioner argued that the standard's 
current test protocol ``directly dictates the level of the air bag's 
inflator power and it is the level of inflator power that unnecessarily 
increases the risk of injury to vehicle occupants during air bag 
deployment.'' AAMA asserted that its recommended test protocol would 
allow for lower powered inflators to be introduced into the market as 
quickly as possible while maintaining air bag protection for all 
occupants.
    In its August 1996 petition, AAMA provided the parameters for its 
recommended pulse along with a suggested mathematical formula, called a 
sine pulse. The sine pulse suggested by AAMA is described by the 
mathematical function: A=15 sin (t/143) Gs.
    After examining the sled test protocol initially advocated by AAMA, 
NHTSA concluded that the standardized sled pulse suggested in the 
petition is representative of a very soft, or benign crash. Indeed, the 
agency wondered whether the pulse were so benign that a vehicle could 
meet the requirements for protecting an unbelted dummy without an air 
bag.
    To answer this question, NHTSA tested a 1993 Taurus according to 
the sled test protocol recommended by AAMA, i.e., the 143 millisecond 
(msec) sled pulse (15 g peak). The vehicle did not have a passenger air 
bag. Although the vehicle had a driver air bag, it was deactivated so 
that it would not deploy. Although protected by neither safety belts 
nor air bags, neither of the dummies had responses that exceeded the 
injury criteria specified in Standard No. 208.
    In its November 13, 1996 letter, AAMA suggested that the agency use 
a more severe crash pulse, 125 msec., which corresponds to 17.1 g. AAMA 
also argued that the agency should consider injury measurements for the 
neck in evaluating the crash pulse, rather than focusing solely on 
whether vehicles without air bags could pass the current Standard No. 
208 injury criteria (HIC, chest and femur loads) in a test using the 
pulse. AAMA indicated that a vehicle could not meet appropriate neck 
injury assessment reference values (IARV's) in a test using the pulse 
without an air bag.
    NHTSA notes that the revised AAMA recommended crash pulse is 
similar to that experienced by a large car in a Standard No. 208 test, 
but milder than that experienced by a typical small car, utility 
vehicle, or light truck. The PRE provides additional information about 
crash pulses.
    In December 1996, NHTSA conducted several tests of a 1993 Taurus 
according to the revised sled test protocol recommended by AAMA, i.e., 
125 msec, 17.1 g. The agency repeated the same test it had conducted 
with the earlier pulse, i.e., a no-air-bag test with unbelted 50th 
percentile male dummies. However, NHTSA also measured forces on the 
neck so that it could make calculations relative to IARV's. The agency 
also conducted tests with baseline and depowered air bags, and with 
fifth percentile female dummies.
    NHTSA was still reviewing data calculations for this new test 
series as this notice was being completed. The agency expects to place 
the data in the docket at, or shortly after, the time this notice is 
published. NHTSA requests comments on what conclusions should be drawn 
from the data and on how the results of the tests should be factored 
into the agency's final decision concerning this proposal.
    There are potential advantages and disadvantages to the approach of 
using a standardized crash pulse representative of a large car as a 
temporary means of addressing air bag fatalities to children. The 
approach provides maximum flexibility to manufacturers in addressing 
these fatalities. In its 1984 rulemaking establishing the automatic 
protection requirements that were in effect until the implementation of 
ISTEA, NHTSA recognized that technical problems existed in designing 
air bags that would not pose a danger to unrestrained small children in 
small cars. Because the crash pulse of small cars is much more severe 
than that of large cars, more aggressive air bags are needed to meet 
the standard's injury criteria. The agency stated:

    Manufacturers claim that little development work has been done 
with air bags for small (e.g., subcompact or smaller) cars and that 
a particular problem in these vehicles is how to protect small 
children, who are not properly restrained, from the more rapidly 
deploying air cushion in such vehicles. The Department believes that 
this problem can be mitigated and that technical

[[Page 822]]

solutions are available, as described in the FRIA. However, the lack 
of experience in this area, as well as the lack of experience for 
some companies in any form of air bag development, make the 
Department reluctant to mandate across-the-board air bags. 49 Fed. 
Reg. 29001, July 17, 1984; See July 11, 1984 FRIA, pp. III-7 to 11.

    The AAMA recommended sled test approach would essentially permit 
the auto manufacturers to use air bags for small cars and other 
vehicles with severe crash pulses (e.g., utility vehicles and trucks) 
that are similar to the ones they use for large cars. This would 
eliminate some of the problems that exist in designing air bags for 
these vehicles that are not aggressive to children, i.e., the risk of 
aggressivity would be normalized for all vehicles.
    Another advantage of a sled test approach is that it reduces the 
time and cost of doing certification testing, since sled tests are less 
destructive of the vehicle. Further, many more sled tests can be 
conducted in the same time period, since the motor vehicle industry and 
its suppliers have substantially greater capacity to conduct sled tests 
than barrier tests.
    The primary disadvantage of using a standardized crash pulse 
representative of a large car is that the test will be less 
representative of actual performance for small cars and other vehicles 
with severe crash pulses, i.e., the test measures only air bag 
performance and not total vehicle performance. The approach also 
eliminates the effect of angle test requirements, which ensure 
protection in frontal impacts that occur at a range of angles rather 
than purely head-on. However, given that recent NHTSA analyses indicate 
that current fatality reducing benefits of air bags drop off rapidly as 
crashes diverge from direct ``head-on'' collisions, deleting the 
requirement for meeting injury criteria in a 30 degree test might not 
substantially degrade the ``real world'' benefits of air bags in such 
crash configurations. (``Fatality Reduction by Air Bags, Analyses of 
Accident Data through early 1996,'' August 1996 NHTSA Technical Report, 
DOT HS 808 470) NHTSA requests comments on this issue.
    As a practical matter, the AAMA recommended sled test approach 
appears to permit more depowering than the 80 g approach. Under the 80 
g approach, Standard No. 208's HIC requirement appears to preclude 
depowering much beyond the 20 to 35 percent range. The agency does not 
know how much depowering would be permitted by the AAMA approach, but 
believes it could be considerably greater than 35 percent, at least for 
vehicles that currently experience a severe crash pulse in the current 
Standard No. 208 test. While this maximizes manufacturer flexibility in 
addressing the fatalities to children, it also raises the possibility 
of greater adverse safety tradeoffs, especially to unbelted teenage and 
adult occupants.
    In the context of a temporary amendment to Standard No. 208, 
however, the agency believes it is important to distinguish between 
what the manufacturers might technically be permitted to do and the 
actions they would actually take in response to a regulatory change. 
Because of the substantial differences among current air bags, it is 
likely that very different levels of depowering are needed for 
different air bags in order to significantly reduce the risk of child 
fatalities. For some air bags, 10 percent depowering may be necessary; 
for others, 60 percent depowering may be necessary.
    Because the same standards apply to all vehicles, it is possible 
that any regulatory change that would permit 60 percent depowering of 
the most aggressive air bags would permit greater than optimal 
depowering of other air bags. That does not mean, however, that 
manufacturers would depower all air bags to the maximum extent 
permitted by the amendment. Instead, the agency anticipates that the 
manufacturers would only depower particular air bags to the extent 
needed to address the child fatality problem, and preserve unbelted 
occupant protection to the maximum extent possible.
    As part of proposing the AAMA recommended sled test approach, the 
agency is proposing to add neck injury criteria for the 50th percentile 
male dummy. As indicated above, AAMA argued that the agency should 
consider injury measurements for the neck in evaluating the crash 
pulse. The source of the proposed neck criteria is ``Anthropomorphic 
Dummies for Crash and Escape Systems,'' AGARD Conference Proceedings of 
NATO, July 1996, AGARD-AR-330. A copy of the relevant pages is being 
placed in the docket. The agency notes that GM uses the same neck 
criteria for its IARVs. Data provided by AAMA indicate that, in 
general, all of these neck criteria could not be met without an air 
bag.
    The proposed neck injury criteria represent peak values for very 
short duration loading. Much lower loads can be tolerated for longer 
duration loading. Time dependency criteria may need to be specified. 
The agency solicits comments on this subject.
    The agency is proposing a test procedure similar to that presented 
in AAMA's petition. NHTSA notes that the proposed procedure specifies 
that the vehicle, or ``a sufficient portion of the vehicle to be 
representative of the vehicle structure,'' is mounted on the sled. The 
agency requests comments on the practicality of conducting sled tests 
with whole vehicles, and on whether the quoted language can be made 
more objective.
    NHTSA notes that AAMA included in its initial petition both a 
recommended crash pulse and specified corridors for that pulse. The 
agency believes that it is necessary to specify corridors in addition 
to a specific pulse, because it is generally not possible to duplicate 
exact pulses. Manufacturers would be required to certify that their 
vehicles comply with the standard's performance requirements for all 
tests within the specified corridors. The agency notes that AAMA has 
not provided corridors for its revised crash pulse, and has written to 
AAMA requesting it to provide a figure showing the mathematical 
equation for the revised pulse, a graph of the pulse and corridors for 
the pulse. This information will be docketed as soon as possible after 
it is received by the agency. While the proposed regulatory text 
specifies only a specific crash pulse and not the corridors for that 
test, the agency expects to include such corridors in the final rule.
3. Request for Additional Information
    In order to help it reach a final decision, the agency is 
requesting additional information in several areas.
    First, the agency is requesting additional information and data to 
help it refine its estimates of the potential benefits and net effects 
on safety that would be likely to result from depowering. As discussed 
above, the estimates presented in the PRE and summarized above are 
necessarily based on very limited data. The agency requests commenters 
to address the analyses presented in the PRE, including what 
conclusions should be drawn from the various test data, modeling data, 
Holden study, and other information presented in that evaluation, 
concerning the effect of depowering on fatalities and injuries. The 
agency also requests commenters to provide additional relevant 
information, including test data, real world studies, and engineering 
analyses.
    Second, the agency recognizes that there are significant 
uncertainties associated with the analyses of the available data and 
the resulting estimates of benefits and disbenefits. If, contrary to 
the agency's expectation and best judgment, this rulemaking were to

[[Page 823]]

result in a large net loss of life, would taking action (through the 
adoption of the proposed amendment) to save the children and short 
adult drivers being fatally injured by air bags still be the correct 
policy choice?
    Third, the agency is seeking comment on the sled pulse test 
recently recommended by AAMA. The agency has written to AAMA requesting 
information on why AAMA selected the particular recommended pulse, the 
amount of depowering that would be permitted for various vehicle types, 
how those changes would translate into 30 mph barrier test results, and 
specific manufacturer plans (on a model-by-model basis, if possible) 
concerning the amount of depowering that would occur if that 
alternative is adopted in the final rule. This information will be 
docketed as soon as possible after it is received by the agency. The 
agency also requests specific estimates on the overall impacts on 
safety, for children, belted and unbelted passengers, and belted and 
unbelted drivers.
    Fourth, NHTSA requests specific analysis comparing the potential 
benefits and net effects on safety of the two proposed alternatives. 
The agency notes that, in a November 13, 1996 submission, AAMA provided 
estimates concerning its members' ability to depower air bags under 
various alternative amendments to Standard No. 208. AAMA stated that, 
for purposes of its analysis, depowering was defined as reducing the 
force produced by air bags to a level which is estimated to reduce the 
risk of air bag related fatalities to a 5th percentile unbelted female 
and unbelted child as close to zero as possible, while still meeting 
all belted occupant injury criteria. According to AAMA, this generally 
corresponds to a 25 to 35 percent average reduction in total inflator 
output and peak mass flow. AAMA provided the following chart:

AAMA Estimates for Air Bag Depowering

    The percentage of air bag systems that could be depowered noted 
below is based on engineering judgment of AAMA members relative to the 
ability to depower the current air bag design to a level needed to 
provide meaningful benefit.
Regulatory Action #1--Raise Chest Criterion to 80 g's
passenger cars--36%
trucks--27%
total--31%

    Leadtime to implement--6 to 9 months to 4 years
Regulatory Action #2--80 g's + delete angle barrier
passenger cars--43%
trucks--41%
total--42%

    Leadtime to implement--6 to 9 months to 3 years
Regulatory Action #3--80 g's + delete angle barrier + 15 msec HIC
passenger cars--48%
trucks--57%
total--53%

    Leadtime to implement--6 to 9 months to 3 years
Regulatory Action #4--125 msec Generic Sled Test
    100% of total fleet--leadtime to implement--6 to 9 months, complete 
within 2 years.
    Based on compliance data and its limited testing of depowered air 
bags, the agency believes that an 80 g requirement would permit 
manufacturers to depower essentially all of their vehicles by 20 to 35 
percent, while AAMA estimates that only 31 percent of vehicles could be 
depowered ``to a level needed to provide meaningful benefit.''
    One reason for the difference in the assessment of the sufficiency 
of the 80 g requirement is that the manufacturers contemplate 
depowering more than 20-35 percent in the case of the more aggressive 
air bags. As discussed earlier in this notice, the agency's testing 
indicates that a considerably higher level of depowering might be 
needed for some vehicles to significantly reduce the chance of fatality 
to out-of-position children.
    NHTSA has not conducted angle tests with depowered air bags, so 
another reason for the difference might be that Standard No. 208's 
current angle test requirement could be a limiting factor even with an 
80 g requirement.
    The agency requests the individual manufacturers to provide 
specific analysis, on a model-by-model basis, if possible, comparing 
the amount of depowering that would be permitted by an increase in the 
chest acceleration limit alone to that which would be permitted by the 
AAMA generic sled pulse test, and describing the reasons for any 
differences in these two levels of depowering. NHTSA has already 
requested this information from AAMA and will docket it as soon as 
possible after it is received by the agency.
    Fifth, NHTSA is requesting additional information concerning the 
extent of the existing problem of driver fatalities and injuries from 
air bags, and the amount of depowering that would be needed for various 
vehicle types to address those fatalities and injuries. As discussed 
earlier in this notice, there are substantial differences between the 
passenger and driver air bag problems. While the annual number of child 
fatalities is very small but growing steadily, the annual number of 
adult fatalities does not appear to be growing. While the agency is 
aware of 18 children who have been fatally injured by air bags this 
year, it is aware of only one driver who has been fatally injured by an 
air bag in the United States during the same period. This apparent 
nearly total absence of driver fatalities has occurred despite the 
greater than two-to-one ratio of vehicles with driver air bags to 
vehicles with passenger air bags and the four-to-one ratio of drivers 
to front seat passengers. (As noted above, however, the agency's 
figures for driver fatalities are not the result of a census.) 
Moreover, while most child fatalities have occurred in very recent 
model year vehicles, the agency is aware of only one woman 5 feet 2 
inches or less who has died in a post model year 1992 vehicle. Finally, 
the ratio of lives saved by air bags to persons fatally injured is very 
different for driver air bags than passenger air bags. Driver air bags 
are estimated to have saved 1500 lives, as compared to 19 persons 
fatally injured. Passenger air bags are estimated to have saved 164 
lives, as compared to 32 persons fatally injured.
    There are also considerable differences between the size and basic 
designs of driver and passenger air bags, and the mechanisms by which 
drivers and children are likely to become too close to the air bag. As 
discussed earlier in this notice, unrestrained or improperly restrained 
children are likely to be propelled up against the air bag before 
deployment as a result of pre-crash braking, and children in rear-
facing infant restraints are positioned with their heads up against the 
air bags. Since drivers have their feet on the brake and/or accelerator 
pedals and/or floor and are holding the steering wheel, they are not 
likely to be propelled forward as a result of pre-crash braking to the 
extent that children are. Pre-braking and crash forces will, however, 
cause drivers to move toward the air bag. Drivers who sit very close to 
the steering wheel are at greater risk of being too close to the air 
bag at the time of deployment, especially if they are unrestrained.
    Because driver air bags have been produced in large numbers for 
several years longer than passenger air bags, the vehicle manufacturers 
have had time in a number of instances to redesign driver air bags to 
incorporate a number of

[[Page 824]]

countermeasures that reduce the risk to out-of-position occupants. In 
deciding whether to adopt its proposal to reduce the stringency of 
Standard No. 208 as it applies to driver air bags, the agency will 
therefore take care that it is assessing both current and expected air 
bag designs.
    By way of illustration, General Motors commented in December 1995 
that it has introduced a number of air bag system features that 
according to its test results should reduce the risk of inflation 
induced injury. These features include minimized inflator output and 
bag size, module cover tear seam geometry, low break-out force module 
cover, bag fold, and recessed air bag module. General Motors also 
stated that it was in the process of introducing air bag systems that 
include a number of features that can help to further reduce the 
inflation-induced loads to which an occupant can be subjected. These 
features (which repeat some of the earlier ones listed by that company) 
include recessed air bag modules, new bag folds, improved air bag 
module tear seam geometries, low break-out force air bag module covers, 
minimized bag volumes, low output inflators, and air bag venting 
technologies.
    NHTSA is also aware that other companies have also redesigned 
driver air bags in ways that should reduce air bag aggressivity. Agency 
testing of several new designs shows a substantial reduction in the 
risk to out-of-position occupants, especially with respect to chest 
injury, measured as V*C. However, the agency also tested some driver 
air bags that showed a substantial reduction in some injury reference 
values and increases in others.
    NHTSA requests information on the potential which current driver 
air bags have for creating adverse side effects. Among other things, 
the agency requests vehicle manufacturers to provide detailed 
information, on a model-by-model basis, if possible, concerning all 
relevant design changes they have made, or expect to make, in their 
vehicles that may have reduced, or will reduce, the risk of injury or 
fatality to drivers from air bags. This would include changes in air 
bag designs, including deployment threshold changes, and changes in 
related vehicle components. This information will help the agency 
assess the potential of adverse side effects associated with model year 
1997 vehicles, as opposed to the potential associated with model year 
1990-92 vehicles.
    The agency also requests information on the number of driver air 
bag fatalities that have occurred to date. NHTSA does not have as much 
information on driver fatalities as child fatalities, because it does 
not have the resources to investigate every adult fatality that occurs 
in a vehicle with an air bag. Therefore, there may be driver fatalities 
that the agency is not aware of. NHTSA is especially interested in 
knowing about fatalities that have occurred over the past three years, 
especially involving late-model vehicles.
    NHTSA also requests comments on the extent to which depowering of 
current air bags would address driver air bag fatalities, and on the 
extent of the associated safety tradeoffs. Finally, the agency requests 
comments and data concerning the extent of the need to change Standard 
No. 208 to permit various levels of depowering, and on the alternatives 
of raising the standard's chest g limit and/or adopting the AAMA 
recommended generic sled pulse test.
    In view of the potentially substantial disbenefits associated with 
depowering driver air bags, the agency requests comment about the 
advisability of limiting the proposed amendment to passenger air bags 
only. The agency requests specific information about the cost and 
leadtime implications of excluding driver air bags from the amendment 
as well as the effects it would have on reducing the magnitude of the 
apparent disbenefits associated with depowering driver air bags. In 
making that request, NHTSA recognizes that considerable depowering of 
driver air bags is already possible under the current standard.

D. Consideration of Other Alternatives

    In developing this proposal, NHTSA considered an array of 
regulatory and nonregulatory (e.g., education) approaches that would 
address the air bag safety problem.
    Other regulatory approaches to facilitate depowering that have been 
advocated by the industry include dropping the unbelted test 
altogether, or requiring that the unbelted requirements be met at 
speeds up to 25 mph instead of 30 mph.
    NHTSA is not proposing to drop the unbelted test altogether. A 
number of vehicle manufacturers have argued that the inclusion of 
unbelted test requirements in Standard No. 208 should be reconsidered 
in light of the fact that belt use has increased from 14 percent in 
1983 to around 68 percent today. The agency recognizes that, at some 
point, belt use might rise to a point at which retention of the 
unbelted test requirements might no longer be appropriate. The agency 
notes that belt use in Australia is over 95 percent, and averages 93 
percent in Canada. However, as noted above, the belt use among fatally 
injured vehicle occupants is less than 40 percent. Since smart air bags 
may soon be available that adjust air bag deployment levels based on 
belt use or nonuse, the possible need to amend the unbelted test 
requirements may be relatively short-lived. NHTSA will consider the 
issue of the unbelted test requirements in the context of its 
forthcoming rulemaking on smart air bags. If it appears that such smart 
air bags will not be available in the near term, the agency will also 
consider whether there might be a percentage of belt use at which the 
agency should examine changing the unbelted test requirements and 
whether any legislative amendments might be necessary for that purpose.
    The agency is also not proposing to reduce the unbelted test speed 
to 25 mph. While this approach was advocated in the past by Ford, Ford 
has now reached consensus with the other members of AAMA on the 
approach of replacing the unbelted crash test requirement with a sled 
test protocol incorporating a standardized crash pulse. In addition, 
the agency believes that the proposed approaches are preferable to 
reducing the test speed because they would allow a more rapid 
introduction of depowered air bags.
    Given the possibility that amending Standard No. 208 to permit 
significant depowering might lead to a reduction in the lives saved by 
air bags, NHTSA has assessed other available approaches to the air bag 
safety problem in terms of their relative timeliness, effectiveness and 
net effect on safety. The results of such a comparative assessment are 
relevant to deciding whether there is a need to reduce stringency of 
the standard and, if so, for how long. The agency has considered the 
following alternatives in addition to depowering. (There is some 
overlap between the alternatives; for example, smart air bags may 
incorporate some design features that could also be used individually.)
    Behavior-Related Actions Only. One possibility would be for NHTSA 
to focus entirely on behavior-related actions, such as public 
information efforts, encouraging the States to improve and enforce 
their safety belt and child restraint use laws, requiring improved 
warning labels, and permitting or requiring passenger manual cut-off 
switches (a technological change which would also require behavioral 
changes to be effective) in all vehicles. Behavioral changes are 
especially relevant to the problem of child fatalities caused by air 
bags, since these fatalities can be prevented by behavioral means, 
e.g., ensuring that

[[Page 825]]

children always buckle up and that they sit in the back seat whenever 
possible.
    NHTSA is actively pursuing efforts to bring about behavioral 
changes. The agency's efforts include its public education campaigns, 
addressed at length in the August 1996 NPRM and other Federal Register 
notices, and the agency's final rule (issued November 22, 1996) 
amending Standards No. 208 and No. 213 to require improved labeling to 
provide better assurance that drivers and other occupants are aware of 
the dangers posed by air bags to children.
    As discussed above, NHTSA is a part of a coalition including 
automobile manufacturers, air bag suppliers, insurance companies and 
safety organizations working to improve safety belt use by a variety of 
means, including education efforts, urging the States to adopt primary 
enforcement safety belt use laws, and improving enforcement of seat 
belt and child seat use laws. To the extent that these efforts are 
successful, belt use rates should increase.
    The agency's rulemaking concerning manual cutoff switches for 
passenger air bags also represents a way of reducing air bag fatalities 
by behavioral means. The switches provide drivers, in vehicles lacking 
a back seat large enough to accommodate a rear-facing infant seat, with 
a means of ensuring that their young children, particularly infants, 
would not be harmed by the air bag.
    However, while behavioral changes are an important part of the 
efforts to reduce low speed fatalities due to air bags, it is not 
realistic to expect that those efforts will fully solve the problem. 
This is illustrated by the number of drivers who continue to drive 
without safety belts and the number of children who remain 
unrestrained, despite decades of efforts to encourage people to wear 
safety belts and use child restraints, and the existence of laws 
requiring such use in most states. Accordingly, it is also necessary 
for the agency to pursue technological changes.
    Higher Deployment Thresholds--i.e., Increasing the Vehicle Speed at 
Which Air Bags Deploy. NHTSA has also considered whether vehicle 
manufacturers should be required to increase the minimum vehicle speed 
at which air bags deploy, and possibly have different deployment 
thresholds for the unbelted and belted conditions, as a short-term 
solution for reducing air-bag-induced fatalities and injuries. This 
would lessen the number of deployments at low speed where the 
possibility of serious injury for occupants (even unrestrained 
occupants) is small.26
---------------------------------------------------------------------------

    \26\ As part of a comprehensive rulemaking on automatic 
restraints (then called ``passive restraints''), in 1970 NHTSA 
proposed to require that air bags not deploy when the vehicle 
impacts a fixed barrier at any velocity less than 15 miles per hour, 
at any angle. 35 Fed. Reg. 16937, at 16938; November 3, 1970. 
However, after considering opposing comments from vehicle 
manufacturers, the agency did not adopt this requirement because it 
determined that it was preferable to allow manufacturers freedom in 
the design of their protective systems at all speeds. 36 Fed. Reg. 
4600, at 4602; March 10, 1971.
---------------------------------------------------------------------------

    As indicated above, CFAS and Public Citizen requested in their 
petition that, for vehicles without dual stage inflators, a minimum 
``trigger speed'' of 10 mph barrier equivalent velocity (BEV) be set 
beginning with the 1998 model year for passenger cars and 1999 for 
light trucks. The CFAS petition submitted a few days earlier had 
suggested a 12 mph minimum deployment threshold. Mercedes Benz 
suggested in its comment on the August 1996 NPRM the possibility of 
using thresholds as high as 18 mph regardless of belt use, as a short-
term means of addressing the problem of low speed fatalities to 
children.27 NTSB recommended that the agency evaluate the effect 
of higher deployment thresholds for passenger air bags in combination 
with certain recommended changes in air bag performance certification 
testing, and then modify the deployment thresholds based on the 
findings of the evaluation. The Holden air bag, in addition to being 
designed to deploy less aggressively, has significantly higher 
thresholds than typical U.S. air bags. As noted above, Holden bags have 
a ``no-fire'' threshold of 12.4 mph and an ``always-fire'' threshold of 
17.4 mph. While thresholds vary for U.S. air bags, a representative one 
has a ``no-fire'' threshold of 9 mph and an ``always-fire'' threshold 
of 14 mph.28
---------------------------------------------------------------------------

    \27\ That company currently uses a threshold of 12 mph for 
unbelted occupants and 18 mph for belted occupants. If no occupant 
is present, the air bag does not deploy, regardless of the speed.
    \28\ The agency notes that regardless of what nominal design 
threshold is selected by a manufacturer, some deployments will occur 
at speeds below that nominal value, and some air bags will not 
deploy at speeds slightly above that value. The range of delta V's 
at which a particular air bag may either deploy or not deploy is 
dependent on a number of factors, including manufacturer efforts to 
fine-tune the deployment decision to reflect different crash 
conditions with the same delta V, and variability inherent in air 
bag designs.
---------------------------------------------------------------------------

    NHTSA stated in its August 1996 NPRM that it is interested in 
whether increasing the minimum vehicle speed at which an air bag 
deploys, and possibly having different deployment thresholds for the 
unbelted and belted conditions, may be an effective way to reduce air 
bag-induced injuries. An examination of the child fatalities that have 
occurred to date shows why such an increase might be effective.
    Of the 32 crashes in which deployment of the passenger air bag 
caused a child fatality, NHTSA has, to date, analyzed the severity of 
24 of those crashes. The estimated change in velocity (delta V) was 20 
mph or less in 23 cases, 15 mph or less in 20 cases, and 10 mph or less 
in eight cases. For the remaining case in the group of 23, delta V was 
estimated at 20-25 mph. For an additional four cases, the agency did 
not estimate crash severity but did a damage estimate. Damage severity 
was low in three cases and moderate in the fourth. The remaining four 
cases out of the 32 crashes are still under investigation. These data 
suggest that a moderate increase in threshold could make a significant 
contribution to reducing child fatalities due to air bags.
    NHTSA recognizes that there are many highly complex issues involved 
in selecting thresholds, including leadtime issues and safety 
tradeoffs. The agency recognizes that the use of a higher threshold, in 
combination with the mechanical crash severity sensors used by some 
vehicle manufacturers, could delay the signal to inflate and thus 
provide less time for the air bag to deploy, and possibly necessitate 
even more aggressive air bag deployments. NHTSA believes this problem 
could be addressed by adding an additional mechanical sensor, but that 
would involve a hardware change and require additional leadtime. The 
agency believes that the leadtime to achieve universal usage of 
electronic sensors would be at least two years. For vehicles which 
already have electronic sensors, there would be a shorter leadtime for 
increasing thresholds.
    Additional tradeoffs involve the possibility of increased non-fatal 
injuries. Auto manufacturers have stated that selection of thresholds 
is typically based on their analysis of the crash severity at which 
serious facial, head, and brain injuries may occur. However, the agency 
believes that current steering assembly designs might permit thresholds 
to be increased without affecting the risk of facial fractures.
    NHTSA believes that manufacturers could significantly increase 
deployment thresholds and still comply with the current requirements of 
Standard No. 208, although the agency does not have specific 
information concerning how high. Standard No. 208 does not specify a 
threshold requirement but does require vehicles to pass crash test 
requirements at speeds up to 30 mph. The agency believes that most, and 
perhaps all current vehicles could

[[Page 826]]

probably pass the unbelted crash test requirements without air bags at 
speeds as high as 16 mph. Therefore, for manufacturers with the 
capability of increasing thresholds quickly, the necessity of meeting 
the injury criteria at speeds below the higher thresholds does not 
appear to be an impediment. The agency requests comments on whether 
this belief is correct.
    NHTSA notes that mandating a minimum deployment threshold would be 
design-restrictive and could undermine the development of two-stage 
systems that could deploy ``softer'' air bags at lower speeds.
    The agency requests commenters to provide analysis comparing the 
benefits/disbenefits and leadtime for increasing deployment thresholds 
versus depowering.
    Dual Stage Inflators. Public Citizen and CFAS petitioned for the 
agency to amend Standard No. 208 to require dual stage inflation air 
bags beginning with the 1999 model year. The petitioners stated that 
dual inflation bags offer the best solution in the near future, as they 
neither surrender protection for adults in high-speed crashes, nor 
sacrifice low-speed crash protection for children. The petitioners 
asserted that inflator deployment and trigger speeds can be adjusted 
now without waiting until the 21st century for smart air bags that use 
infrared or sonic sensors to determine whether there is an out-of-
position occupant.
    NHTSA notes that the leadtime for implementing dual stage inflators 
is longer than for depowering. As indicated above, manufacturers can 
begin introducing depowered air bags in six to nine months and 
potentially complete their introduction of depowered air bags by a year 
later. Based on comments from suppliers, the earliest that dual stage 
inflators could begin to be implemented is for model year 1999, i.e., 
September 1998.
    While the leadtime is longer, it appears that dual stage inflators 
could provide essentially all of the benefits associated with 
depowering, without raising the same possibility of safety tradeoffs. 
This is because such designs would in essence provide a ``depowered'' 
air bag for low to moderate speed crashes (and possibly all belted 
crashes), and a fully powered air bag to provide protection to unbelted 
occupants in higher speed crashes. The agency notes that dual stage 
inflators might qualify as smart air bags.
    Other Air Bag-Related Changes, Not Including Smart Bags. In its 
November 1995 request for comments, the agency requested comments on 
many variables in air bag design and related vehicle design that can 
affect aggressivity. Variables related to air bag design include air 
bag volume, fold patterns, tethering, venting, mass/material, shape and 
size of air bag module opening, and module location and deployment 
path. Related vehicle design variables include such things as recessing 
the inflator/air bag in the steering wheel assembly or in the dash, 
pedal adjusters, and safety belt pretensioners. The agency notes that 
Holden safety belt systems use webbing clamps, which help reduce the 
payout and spooling of the webbing. In its August 2, 1996 comment, CFAS 
cited many of these variables (as well as ones discussed above in 
connection with its petitions) in arguing that other means of reducing 
air bag aggressivity should be used before manufacturers resort to 
decreasing the inflation rates.
    NHTSA agrees that there are many variables besides inflator power 
which affect air bag aggressivity, including many cited by CFAS. Many 
of these changes already are being made. However, any currently 
unplanned changes relating to these other variables would generally 
require unanticipated hardware changes, which would take longer to 
implement than depowering. The agency believes that hardware changes 
require leadtimes of at least two years. In addition, the agency does 
not have information showing that these types of changes would be as 
effective as depowering in addressing child fatalities.
    Smart Air Bags. NHTSA has similarly considered how quickly 
manufacturers could begin installation of smart air bags. As discussed 
above, the vehicle manufacturers have indicated that they plan to 
introduce these devices as soon as they become available. Several 
suppliers commenting on the August 1996 NPRM indicated that smart air 
bags can begin to be phased in beginning with the model year 1999 
fleet, i.e., approximately September 1, 1998.
    Tentative Conclusions about Alternatives. As the agency considers 
technological alternatives to address the adverse side effects of air 
bags, several things seem evident. First, for many vehicles, depowering 
has a shorter leadtime than any of the other alternatives. While 
manufacturers can begin introducing depowered air bag vehicles in six 
to nine months and potentially complete the depowering of the air bags 
in their vehicles within about a year after they begin introduction, 
dual level inflators and other smart air bags cannot begin to be phased 
in until at least September 1, 1998. The agency has less information on 
the leadtime for raising deployment thresholds, but it appears that it 
would take at least two years to switch from mechanical to electronic 
sensors.
    Second, there are various alternatives that may be superior to 
depowering, i.e., alternatives that result in equal or greater benefits 
without raising the possibility of adverse safety tradeoffs, but whose 
leadtime is longer than that of depowering. Therefore, while depowering 
appears to be an appropriate short-term approach, there is no need for 
permanently changing the Standard to enable manufacturers to fully 
address the adverse side effects of air bags.
    NHTSA also believes it is important to emphasize that a change in 
Standard No. 208 is not required to permit manufacturers to implement 
these other alternatives. \29\ The agency expects to ultimately require 
smart air bags through rulemaking. In the meantime, the agency is not 
endorsing depowering over other solutions. Instead, the agency is 
proposing a regulatory change to add depowering to the alternatives 
available to the vehicle manufacturers to address this problem on a 
short-term basis. To the extent that manufacturers can implement 
superior alternatives for some vehicles, the agency would encourage 
them to do so.
---------------------------------------------------------------------------

    \29\ All of these various other alternatives, i.e., dual level 
inflators, smart air bags, higher deployment thresholds, and the 
replacement of mechanical sensors by electronic ones, are permitted 
by the existing provisions of Standard No. 208. The Standard already 
provides considerable design flexibility for manufacturers. The 
Standard's automatic protection requirements are performance 
requirements and do not specify the design of an air bag. Instead, 
vehicles must meet specified injury criteria, including criteria for 
the head and chest, measured on properly positioned test dummies, 
during a barrier crash test, at speeds up to 30 mph.
    While the Standard requires air bags to provide protection for 
properly positioned occupants (belted and unbelted) in relatively 
severe crashes, and very fast air bags may be necessary to provide 
such protection, the standard does not require the same speed of 
deployment in the presence of out-of- position occupants, or even 
any deployment at all. Instead, the standard makes possible the use 
of dual or multiple level inflator systems and automatic cut-off 
devices for out-of-position occupants and rear-facing infant 
restraints. Concepts such as dual level inflator systems and devices 
that sense occupant position and measure occupant size or weight are 
not new, and were cited by the agency in its 1984 rulemaking. NHTSA 
also notes that Standard No. 208 does not specify a vehicle speed at 
which air bags must deploy, and that thresholds could be raised 
substantially for most current vehicles without creating a Standard 
No. 208 compliance problem. Therefore, regulatory changes are not 
needed to permit manufacturers to implement these solutions.
---------------------------------------------------------------------------

    Some commenters, including Takata, expressed concern that a 
reduction in Standard No. 208's performance requirements may delay the 
introduction of superior alternatives. NHTSA does not believe a short-
term

[[Page 827]]

temporary amendment would result in such a delay. Instead, such an 
amendment would provide maximum flexibility to the vehicle 
manufacturers to address the problem, while they work on better 
solutions. Moreover, the agency's forthcoming proposal for smart air 
bags will seek to ensure that air bags reach their full fatality and 
injury reducing potential.
    NHTSA recognizes, however, that its proposal to permit or 
facilitate depowering of air bags is on a faster track than the 
rulemaking to require smart air bags. Under the agency's rulemaking 
schedule, it plans to issue a final rule concerning depowering before a 
final rule to require smart air bags. Given that NHTSA contemplates 
permitting depowering until smart bags are introduced, the question 
arises of how the agency should limit the duration of the temporary 
amendment for depowering. One approach would be to specify a several 
year duration and revisit the issue in the context of the rulemaking on 
smart air bags. NHTSA requests comments on this issue.
    The agency notes that Public Citizen and CFAS requested that the 
agency require dual stage inflators quickly rather than wait for more 
advanced smart air bags. The agency believes there is a consensus that 
smart air bags are needed to fully address the problem of child 
fatalities. The ``first'' stage of a dual stage inflator would be 
similar to depowered air bags in reducing but not eliminating the 
possibility of serious injury or fatality to an out-of-position child. 
In its August 1996 proposal, NHTSA noted that if it does decide to 
require smart passenger air bags, its leadtime decision would have to 
take into consideration the differing leadtimes for the various kinds 
of smart bags under development, and the fact that the longest 
leadtimes will be those for the more advanced smart bags potentially 
offering the greatest net benefits. The agency also noted that, as a 
practical matter, the longer the time needed to develop and implement 
the most advanced smart bags, the greater the need would be to 
implement interim designs that would protect children automatically.
    These same types of considerations are relevant to the Public 
Citizen/CFAS request. If the ultimate result is for the vehicle 
manufacturers to add smart air bags to their fleets, the agency 
believes that the quickest and most efficient way of accomplishing this 
task would be to go directly to smart air bags, which may include dual 
stage inflators.
    NHTSA requests commenters to address how the agency should consider 
this factor in reaching a final decision on this proposal. The agency 
also requests the vehicle manufacturers to provide their latest 
timetables for implementing measures that will enable them not only to 
solve the problem of the adverse side effects of air bags, but also to 
meet the current unbelted requirements of Standard No. 208, i.e., 60 g 
chest acceleration, 1000 HIC, etc.
    With respect to Advocates' recommendation that the agency not 
predicate major regulatory changes on anything less than clear and 
convincing evidence that a modification will improve safety, NHTSA 
agrees that caution should be exercised in making a regulatory change. 
This is why the agency initiated its test program to evaluate various 
issues related to addressing the problem of low speed air bag 
fatalities and injuries, including the potential safety benefits and 
trade-offs associated with depowering air bags. NHTSA also believes, 
however, that it has a duty to act to address this problem, and promote 
the long term interests of safety, even in the presence of the 
possibility of short-term tradeoffs and inevitable remaining 
uncertainties about the various approaches and alternatives.

E. Effective Date and Comment Period

    The proposed amendment might be major and thus subject to 
Congressional review under the provisions in Title 5 of the United 
States Code concerning Congressional review of agency rulemaking. If 
the amendment is major, the agency requests comments on whether the 
amendment should be make effective immediately upon publication because 
it addresses an urgent safety problem, most particularly the death of 
young children. The proposed amendment would permit or facilitate the 
immediate depowering of air bags, thereby helping to reduce child 
fatalities from air bags. The proposed amendment would not impose any 
new requirements, but instead would provide additional flexibility to 
manufacturers in addressing this problem.
    Given the importance of enabling manufacturers to address this 
urgent safety problem quickly, NHTSA is providing a shortened comment 
period of 30 days.

F. Relationship to Other Actions

    NHTSA invites commenters to address whether and how any of the 
other actions being taken by the agency to address adverse effects of 
air bags should affect its decision concerning this proposal.

VI. Response to AAMA and CFAS Petitions

    This notice constitutes a granting of AAMA's petition for 
rulemaking. The agency is proposing the AAMA sled test as one of the 
alternative amendments in this rulemaking. The agency will consider 
AAMA's request for rulemaking concerning out-of-position occupants in 
the context of the anticipated SNPRM concerning smart air bags.
    The agency is addressing the request of Public Citizen and CFAS 
concerning deployment thresholds in the context of this rulemaking. 
Accordingly, it considers them to have been granted to the extent that 
this notice analyzes and discusses thresholds and subjects that 
material to public comment.

VII. Granting of Petition for Use of 5th Percentile Female Dummy

    NHTSA has decided to grant a petition submitted by Anita Glass 
Lindsey on September 1, 1996, to amend Standard No. 208 to specify use 
of the 5th percentile female test dummy in testing vehicles for 
compliance with the standard's air bag requirements. The purpose of the 
amendment would be to provide greater assurance of the safety of short-
statured women. The agency notes that the existing 5th percentile 
female dummy may need further refinement before it is suitable as a 
device for measuring air bag performance. Further, the simple addition 
of this dummy to the standard would not likely have a significant 
effect on air bag design or performance. To have such an effect, the 
addition would have to be coupled with the adoption of neck injury 
criteria. Currently, there are no neck injury criteria for the 50th 
percentile male dummy used in air bag testing, although proposed 
criteria are included in this notice.
    The agency contemplates initiating a new rulemaking proceeding in 
the future to propose the adoption of the 5th percentile female dummy 
and to specify injury criteria, including neck injury criteria, 
suitable for that dummy.

VIII. Rulemaking Analyses and Notices

A. Executive Order 12866 and DOT Regulatory Policies and Procedures

    NHTSA has considered the impact of this rulemaking action under 
Executive Order 12866 and the Department of Transportation's regulatory 
policies and procedures. This rulemaking document was reviewed by the 
Office of Management and Budget under E.O. 12866, ``Regulatory Planning 
and Review.'' This action has been

[[Page 828]]

determined to be ``significant'' under the Department of 
Transportation's regulatory policies and procedures. The action is 
considered significant because of the degree of public interest in this 
subject.
    The proposed amendments would not impose any new requirements or 
costs, but instead permit or facilitate approximately 20 to 35 percent 
depowering of current passenger air bags. Any cost difference between 
baseline and depowered air bags would be negligible.
    A full discussion of costs and benefits can be found in the 
agency's regulatory evaluation for this rulemaking action, which is 
being placed in the docket.

B. Regulatory Flexibility Act

    NHTSA has considered the effects of this rulemaking action under 
the Regulatory Flexibility Act (5 U.S.C. Sec. 601 et seq.) I hereby 
certify that the proposed amendment would not have a significant 
economic impact on a substantial number of small entities. NHTSA notes 
that the cost of new passenger cars or light trucks would not be 
affected by the proposed amendment.
    The following is NHTSA's statement providing the factual basis for 
the certification (5 U.S.C. Sec. 605(b). The proposed amendment would 
primarily affect passenger car and light truck manufacturers and 
manufacturers of air bags. 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)).
    SBA's size standards are organized according to Standard Industrial 
Classification codes (SIC). SIC Code 3711 ``Motor Vehicles and 
Passenger Car Bodies'' has a small business size standard of 1,000 
employees or fewer. SIC Code 3714 ``Motor Vehicle Parts and 
Accessories'' has a small business size standard of 750 employees or 
fewer. NHTSA believes air bag manufacturers would fall under SIC Code 
3714.
    For passenger car and light truck manufacturers, NHTSA estimates 
there are at most five small manufacturers of passenger cars in the 
U.S. Because each manufacturer serves a niche market, often 
specializing in replicas of ``classic'' cars, production for each 
manufacturer is fewer than 100 cars per year. Thus, there are at most 
five hundred cars manufactured per year by U.S. small businesses.
    In contrast, in 1996, there are approximately nine large 
manufacturers manufacturing passenger cars and light trucks in the U.S. 
Total U.S. manufacturing production per year is approximately 15 and a 
half million passenger cars and light trucks per year. NHTSA does not 
believe small businesses manufacture even 0.1 percent of total U.S. 
passenger car and light truck production per year.
    For air bag manufacturers, NHTSA does not believe that there are 
any small manufacturers of air bags. A separate subsidiary (of a large 
business) set up to manufacture air bags would not be considered a 
small business because of SBA's affiliation rule under 13 CFR 
Sec. 121.103.

C. National Environmental Policy Act

    NHTSA has analyzed this proposed amendment for the purposes of the 
National Environmental Policy Act and determined that it would 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 proposed amendment in accordance with 
the principles and criteria set forth in Executive Order 12612. NHTSA 
has determined that the proposed amendment does not have sufficient 
federalism implications to warrant the preparation of a Federalism 
Assessment.
    In proposing this amendment to permit or facilitate depowering, the 
agency notes, for the purposes of the Unfunded Mandates Act, that is 
pursuing the least cost alternative. As noted above, any cost 
difference between current and depowered air bags is expected to be 
negligible. This alternative was tentatively selected by NHTSA because 
depowering would prevent many of the air bag related fatalities that 
have been occurring and can be implemented more quickly than the other 
alternatives. Further, depowering is the measure that industry itself 
has been recommending as a means for preventing those fatalities.

E. Civil Justice Reform

    This proposed amendment would not have any retroactive effect. 
Under 49 U.S.C. 30103, 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. 30161 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.

IX. Request for Comments

    Interested persons are invited to submit comments on this proposal. 
It is requested but not required that 10 copies be submitted.
    All comments must not exceed 15 pages in length (49 CFR 553.21). 
Necessary attachments may be appended to these submissions without 
regard to the 15-page limit. This limitation is intended to encourage 
commenters to detail their primary arguments in a concise fashion.
    If a commenter wishes to submit certain information under a claim 
of confidentiality, three copies of the complete submission, including 
the purportedly confidential business information, should be submitted 
to the Chief Counsel, NHTSA, at the street address given above, and 
seven copies from which the purportedly confidential information has 
been deleted should be submitted to the NHTSA Docket Section. A request 
for confidentiality should be accompanied by a cover letter setting 
forth the information specified in the agency's confidential business 
information regulation. 49 CFR Part 512.
    All comments received by NHTSA before the close of business on the 
comment closing date indicated above will be considered, and will be 
available for examination in the docket at the above address both 
before and after that date. To the extent possible, comments filed 
after the closing date will also be considered. Comments received too 
late for consideration in regard to this action will be considered as 
suggestions for further rulemaking action. Comments will be available 
for inspection in the docket. The NHTSA will continue to file relevant 
information as it becomes available in the docket after the closing 
date, and recommends that interested persons continue to examine the 
docket for new material.
    Those persons desiring to be notified upon receipt of their 
comments in the rules docket should enclose a self-addressed, stamped 
postcard in the envelope with their comments. Upon receiving the 
comments, the docket supervisor will return the postcard by mail.

List of Subjects in 49 CFR Part 571

    Imports, Motor vehicle safety, Motor vehicles, Rubber and rubber 
products, Tires.

    In consideration of the foregoing, NHTSA proposes to amend 49 CFR 
Part 571 as follows:

[[Page 829]]

PART 571--FEDERAL MOTOR VEHICLE SAFETY STANDARDS

    1. The authority citation for Part 571 of Title 49 would continue 
to read as follows:

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

Alternative One

Amendments to Regulatory Text That is Currently in Effect

    2. Section 571.208 would be amended by revising S6.1.3 and S6.2.3 
to read as follows:


Sec. 571.208  Standard No. 208, Occupant crash protection.

* * * * *
    S6.1.3  The resultant acceleration at the center of gravity of the 
upper thorax shall not exceed 60 g's, except for intervals whose 
cumulative duration is not more than 3 milliseconds. However, for 
vehicles manufactured after [date 30 days after publication of final 
rule in the FEDERAL REGISTER] and before [date would be selected for 
final rule], the acceleration limit is 80 g's, instead of 60 g's.
* * * * *
    S6.2.3  The resultant acceleration calculated from the output of 
the thoracic instrumentation shown in drawing 78051-218, revision R 
incorporated by reference in part 572, subpart E of this chapter shall 
not exceed 60 g's, except for intervals whose cumulative duration is 
not more than 3 milliseconds. However, for vehicles manufactured after 
[date 30 days after publication of final rule in the FEDERAL REGISTER] 
and before [date would be selected for final rule], this acceleration 
limit is 80 g's, instead of 60 g's.
* * * * *
    3. Section 571.208 would be amended by adding Appendix A at the end 
of the section to read as follows:

Appendix A to Sec. 571.208, Standard No. 208

    For vehicles manufactured after [date 30 days after publication of 
final rule in the FEDERAL REGISTER] and before [date would be selected 
for final rule], NHTSA will consider engineering analyses indicating 
that a vehicle will pass the unbelted test requirements with an air bag 
as sufficient to establish that the vehicle's manufacturer exercised 
due care to ensure that the vehicle conforms with the requirement, even 
in the absence of confirming crash testing.

Amendment to Regulatory Text That Would Become Effective September 1, 
1997

    4. Section 571.208 would be amended by revising S6.3 to read as 
follows:


Sec. 571.208  Standard No. 208, Occupant crash protection.

* * * * *
    S6.3  The resultant acceleration calculated from the output of the 
thoracic instrumentation shown in drawing 78051-218, revision R 
incorporated by reference in part 572, subpart E of this chapter shall 
not exceed 60 g's, except for intervals whose cumulative duration is 
not more than 3 milliseconds. However, for vehicles manufactured after 
[date 30 days after publication of final rule in the FEDERAL REGISTER] 
and before [date would be selected for final rule], this acceleration 
limit is 80 g's, instead of 60 g's.
* * * * *

Alternative Two

    5. Section 571.208 would be amended by revising S3 to read as 
follows:
    S3. Application. This standard applies to passenger cars, 
multipurpose passenger vehicles, trucks, and buses. In addition, S9., 
Pressure vessels and explosive devices, applies to vessels designed to 
contain a pressurized fluid or gas, and to explosive devices, for use 
in the above types of motor vehicles as part of a system designed to 
provide protection to occupants in the event of a crash. 
Notwithstanding any language to the contrary, any vehicle manufactured 
after [date 30 days after publication of final rule in the FEDERAL 
REGISTER] and before [date would be selected for final rule] that is 
subject to a dynamic crash test requirement conducted with unbelted 
dummies may meet the requirements specified in S13 instead of the 
applicable unbelted requirement.
    6. Section 571.208 would be amended by adding S13 through S13.2 to 
read as follows:
    S13  Alternative unbelted test for vehicles manufactured before 
[date would be selected for final rule].
    S13.1  HYGE Sled--Crash Simulation Test. Applying the appropriate 
conditions of S8, mount the vehicle, or a sufficient portion of the 
vehicle to be representative of the vehicle structure, on a dynamic 
test platform at the manufacturer's design attitude, so that the 
longitudinal center line of the vehicle is parallel to the direction of 
the test platform travel and so that movement between the base of the 
vehicle and the test platform is prevented. The test platform is 
instrumented with an accelerometer and data processing system having a 
frequency response of 60 Hz channel class as specified in SAE 
Recommended Practice J211 (MAR 95), ``Instrumentation for Impact 
Tests.'' The accelerometer sensitive axis is parallel to the direction 
of test platform travel. The test is conducted at any velocity change 
up to and including 30 mph with acceleration of the test platform shown 
by the curve in Figure 6. An inflatable restraint is to be activated at 
25 2 ms after initiation of the acceleration shown in 
Figure 6. The test dummy specified in S8.1.8, placed in each front 
outboard designated seating position as specified in S11, shall meet 
the injury criteria of S6.1, S6.2, S6.3, S6.4 and S6.5 of this 
standard.
    13.2  Neck injury criteria. A vehicle certified to this alternative 
test requirement shall, in addition to meeting the criteria specified 
in S13.1, shall meet the following injury criteria for the neck in the 
unbelted sled test:
    (a) Flexion Bending Moment--190 Nm. SAE Class 600.
    (b) Extension Bending Moment--57 Nm. SAE Class 600.
    (c) Axial Tension--3300 peak N. SAE Class 1000.
    (d) Axial Compression--4000 peak N. SAE Class 1000.
    (e) Fore-and-Aft Shear--3100 peak N. SAE Class 1000.
    7. Section 571.208 would be amended by adding Figure 6 to read as 
follows:

BILLING CODE 4910-59-P

[[Page 830]]

[GRAPHIC] [TIFF OMITTED] TP06JA97.000



BILLING CODE 4910-59-C
L. Robert Shelton,
Associate Administrator for Safety Performance Standards.

Appendix--Past Public Comments Related to Depowering Air Bags

    Note: This appendix will not appear in the Code of Federal 
Regulations.

    While NHTSA has not issued a specific proposal concerning 
depowering air bags, it did request comments on this subject in both 
the November 1995 request for comments and the August 1996 NPRM. This 
section provides a summary of comments relating to depowering (or 
downloading) air bags, including comments recommending alternative 
short-term approaches. The agency notes that the views expressed on the 
November 1995 request for comments may in some instances be dated, 
since considerable research has been conducted in this area since then.

A. November 1995 Request for Comments

    A number of commenters addressed the issue of depowering air bags, 
primarily in the context of either a recommendation that Ford made to 
reduce the test speed for Standard No. 208's unbelted test from 30 mph 
to 25 mph, or the possibility of raising the limit on chest g's from 60 
to 80. The agency specifically requested comments on the possibility of 
such an increase. A number of commenters, including many vehicle 
manufacturers (Chrysler, Ford, BMW, Volkswagen, Porsche, and Toyota), 
an air bag supplier (Autoliv Development AB), and IIHS, expressed 
support for Ford's recommendation. These commenters stated that this 
change would allow a reduction of approximately 30 percent in the 
kinetic energy required in the air bag system, and that lower kinetic 
energy in the air bag would lower the risk of air bag-induced injuries 
to vehicle occupants.
    GM commented that it agreed with the theory of the Ford 
recommendation and said that it was ``directionally correct.'' However, 
GM said that it has not been shown that a reduction in the unbelted 
test speed to 25 mph would allow manufacturers to reduce the kinetic 
energy in air bag systems enough to influence the actual frequency of 
air bag-induced injuries to vehicle occupants. Nissan went further, 
saying that it would not anticipate any major changes in air bag 
deployment specifications because of a reduction in the unbelted test 
speed from 30 to 25 mph. Nissan suggested that the unbelted test speed 
would have to be reduced to 20 mph to reduce the risk of air bag-
induced injuries in the real world.
    BMW enthusiastically supported the concept of raising Standard No. 
208's chest g limit, but suggested that the limit be raised to 75 g's. 
If this were done, BMW said it would attempt to recertify all of its 
vehicles with less aggressive air bags within one year.
    GM said an 80 g limit would not appear likely to permit any 
appreciable reduction in inflator output, so GM doubted it would reduce 
significantly the potential for air bag-induced injuries. Ford said 
such a change might permit reductions in air bag aggressivity, but to a 
much less significant extent than under its recommendation. Chrysler 
stated that it could not comment on an 80 g limit because it had no 
data to analyze the effects of such a change.
    In a presentation to the agency and supplemental comment submitted 
after the comment closing date, GM suggested an alternative regulatory 
change that it argued would be effective at reducing air bag-induced 
injuries. GM suggested keeping the unbelted testing speed at 30 mph, 
but adopting a crash pulse to ``better reflect'' the crash pulse in 
real world crashes and using a sled test for unbelted testing. This 
concept ultimately became the basis of the petition for rulemaking 
submitted by AAMA in August 1996.
    No manufacturer argued that depowering air bags would totally solve 
the adverse effects associated with children. In commenting on the 
November 1995 request for comments, GM provided the results of a 
depowered air bag inflator study. Based on that study, GM concluded 
that depowered inflators are ``directionally correct,'' but that 
deactivation is needed to meet injury assessment reference values for 
passengers who are at or near the instrument panel. This was said to be 
particularly true for children, because of their lower injury 
tolerance.
    Not all commenters believed that Standard No. 208 should be 
changed. Takata Corporation (Takata), an air bag manufacturer, argued 
that restraint

[[Page 831]]

system technology that has recently become available, combined with 
further improvements that are scheduled to be available within the next 
24 months (i.e., by approximately the beginning of 1998), will 
significantly reduce air bag injuries without the need for any changes 
to Standard No. 208. Takata stated that it is concerned that the 
process of developing improved technology to eliminate air bag injuries 
will be delayed if Standard No. 208 is changed in response to the 
present concerns.
    Advocates opposed reducing Standard No. 208's unbelted test speed. 
That organization claimed that there are several flaws in the Ford 
recommendation. According to Advocates, altering the inflation rate of 
air bags may only address a portion of the problem, may not make any 
difference at all, or may even create other safety concerns. Advocates 
also stated that the Ford recommendation is based entirely on static 
computer modeling that is limited to a single variable, air bag 
inflator rise rates, and that the recommendation is modeled on only an 
adult driver. Advocates stated that NHTSA should be reluctant to 
predicate major regulatory changes on anything less than clear and 
convincing evidence that a modification will improve safety.
    Center for Auto Safety (CFAS) submitted a comment in August 1996 
expressing a variety of concerns about the Ford recommendation, and 
arguing that other means of reducing air bag aggressivity should be 
used before manufacturers resort to decreasing the inflation rates. 
CFAS also stated that initial analysis of the limited data available 
strongly suggests that if NHTSA does anything, it should set a minimum 
threshold speed below which an air bag should not deploy.
    Mercedes Benz suggested that, as a short-term solution, the agency 
consider higher deployment thresholds, as well as the use of weight 
sensors (a type of smart air bag) for passenger air bags. Mercedes 
noted that it currently uses a 12 mph delta V threshold for unbelted 
occupants, and an 18 mph delta V threshold for belted occupants. That 
company indicated that it could use the 18 mph delta V threshold for 
all occupants. Mercedes asserted, however, that this would not 
currently be permitted by Standard No. 208. 1
---------------------------------------------------------------------------

    \1\ Mercedes did not explain the basis for this assertion. The 
Standard does not expressly prohibit such a threshold. Further, with 
appropriate interior design, including energy absorbing materials, 
it should be possible to meet the Standard's performance criteria.
---------------------------------------------------------------------------

B. August 1996 NPRM

    As discussed above, subsequent to the agency's publication of the 
August 1996 NPRM, but before the comment closing date, AAMA submitted a 
petition for rulemaking concerning depowering air bags. AAMA requested 
that NHTSA immediately announce, by means of a ``direct final rule,'' 
an amendment to Standard No. 208 to replace the current 30 mph 
unrestrained dummy barrier crash test requirement with a ``standard 30 
mph unrestrained dummy sled test'' requirement. The petitioner 
contended that the standard's current requirement ``directly dictates 
the level of the air bag's inflator power and it is the level of 
inflator power that unnecessarily increases the risk of injury to 
vehicle occupants during air bag deployment.''
    AAMA and each of its member companies cited the AAMA petition in 
their comments on the August 1996 NPRM and urged that the agency 
favorably respond to the petition.
    The Association of International Automobile Manufacturers (AIAM) 
stated that until smart air bag systems are available and become 
widespread in the fleet, it believes that Standard No. 208 should be 
changed to modify or eliminate the 30 mph unbelted occupant protection 
requirement so that air bags could be made less aggressive. That 
organization stated that not only would this allow less aggressive air 
bags with less risk to out-of-position occupants, but also it would 
allow manufacturers to provide better occupant protection for belted 
occupants through such things as a combination of depowered air bags 
and other restraint system enhancements. AIAM stated that unbelted 
occupants would still have the benefits of air bag protection and a 
lowered risk of out-of-position injury in many frontal crashes.
    Honda stated that it believes the passenger air bag system in its 
vehicles is presently one of the least aggressive relative to the air 
bags on other cars in North America. That company stated, however, that 
still lower inflator output is necessary to ensure reduction of the 
aggressiveness of the passenger air bag. Honda stated that if Standard 
No. 208 were amended to eliminate unbelted testing or to reduce the 
crash test speed, inflator output could be adjusted accordingly, 
reducing the risk of air bag induced injury to out-of position or 
unbelted occupants.
    Takata stated again that it strongly urges NHTSA not to tamper with 
the 30 mph unbelted barrier test as a short-term expedient to reduce 
the risk of air bag injuries to children. That company stated that it 
does not believe this would produce a sufficient reduction in the risks 
to children to jeopardize the proven life saving benefits of air bags 
in high speed crashes.
    The Insurance Institute for Highway Safety (IIHS) stated that 
although changes in the unbelted test requirements in Standard No. 208 
alone will not eliminate all the air bag related fatalities, less 
aggressive inflators have the potential to reduce the risk for infants 
and children as well as for adults. That organization stated that as 
other air bag technology evolves to permit variable levels of 
protection based on crash severity and occupant characteristics, it 
will be possible to further enhance protection for unbelted occupants 
over a wide range of crash severities. IIHS stated that, in the 
meantime, the first and immediate step NHTSA could take would be to 
make appropriate changes to Standard No. 208 that would allow 
manufacturers to reduce the energy in current air bag systems.
    The National Association of Independent Insurers (NAII) stated that 
it believes changing the unbelted test requirements in Standard No. 208 
to permit less aggressive inflators should be a central part of NHTSA's 
efforts to encourage smart systems, and cited concerns expressed by 
IIHS.

[FR Doc. 96-33307 Filed 12-30-96; 11:00 am]
BILLING CODE 4910-59-P