49 CFR Part 571
Federal Motor Vehicle Safety Standards;
AGENCY: National Highway Traffic Safety Administration (NHTSA), DOT.
ACTION: Final rule.
SUMMARY: NHTSA is temporarily amending the agency's occupant crash protection standard to ensure that vehicle manufacturers can quickly depower all air bags so that they inflate less aggressively. The agency is taking this action to provide an immediate, but interim, solution to the problem of 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 occupants.
DATES: Effective Date: The amendments made in this rule are effective [insert date of publication in the Federal Register].
ADDRESSES: Petitions for reconsideration should refer to the docket and notice number of this notice and be submitted to: Administrator, National Highway Traffic Safety Administration, 400 Seventh Street, SW, Washington, DC 20590.
FOR FURTHER INFORMATION CONTACT:
SUPPLEMENTARY INFORMATION:
I. Background.
A. Air Bags: Safety Issues.
B. Current Requirements for Air Bags.
II. Overview and Summary.
III. January 1997 Depowering Proposal.
IV. Summary of Comments.
V. Agency Decision.
B. 80 g's chest injury criterion vs. sled test.
C. Application of the amendment to driver air bags
D. Duration of amendment.
E. Benefits and trade-offs.
1. Neck injury criteria
2. Testing whole vehicles or partial vehicles
3. "Corridor" for crash pulse
4. Air bag activation
5. Test attitude
6. Completion of sled test
G. Miscellaneous Issues
1. Multistage manufacturer certification
2. Effective date
VI. Rulemaking Analyses and Notices.
A. Air Bags: Safety Issues.
Air bags have proven to be highly effective in reducing fatalities from frontal crashes, the most prevalent fatality and injury-causing type of crash. Those crashes result in 64 percent of all driver and right-front passenger fatalities.
B. Current Requirements for Air Bags.
Under Chapter 301 of Title 49, U.S. Code ("Motor Vehicle Safety"), NHTSA is authorized to set Federal motor vehicle safety standards applicable to the manufacture and sale of new motor vehicles and new motor vehicle equipment. Standard No. 208, Occupant Crash Protection, one of the original Federal motor vehicle safety standards issued under this statute, has long required motor vehicle manufacturers to install safety belts to protect occupants during a crash. Beginning in the late 1980's, the standard has required manufacturers to provide automatic protection for frontal crashes, i.e., protection that requires no action by the occupant.
and other specific attributes of each of their vehicles. Further, it leaves them free to select specific attributes for their air bags, such as dimensions and actuation time.
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.(6)
After carefully considering the comments, NHTSA has decided to adopt AAMA's modified unbelted sled test protocol as a temporary alternative to Standard No. 208's current unbelted crash test requirement. This change, coupled with the considerable flexibility already provided by the standard's performance requirements, will provide the vehicle manufacturers with maximum flexibility to quickly address and mitigate the adverse effects of current air bags.
A. Should NHTSA amend Standard No. 208 to permit/facilitate depowering?
A few commenters, however, opposed depowering or otherwise raised concerns about the basic approach of the agency's proposal. The issues raised by those commenters are addressed in this section. Comments concerning how depowering should be accomplished, e.g., what alternative amendment should be adopted, whether the driver side should be included, and the appropriate duration for the amendment, will be discussed in later sections.
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).(8) 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.
B. 80 g's chest injury criterion vs. sled test.
80 g's, or (2) replace the unbelted crash test requirement with a sled test protocol incorporating the 125 millisecond crash pulse. The agency noted that if both of these changes were adopted, a manufacturer could select either alternative at its option, but could not mix the two options.
There are other disadvantages with the sled test, including that a sled test does not simulate the triaxial acceleration characteristics of an actual vehicle crash. In other words, a sled test involves acceleration from only a single preset direction, while pulses for actual vehicle crashes can have significant vertical and lateral components of acceleration that can affect occupant kinematics and restraint performance. Nor does a sled test evaluate dynamic intrusion into and deformation of the passenger compartment; structural crush; the steering column's energy absorbing characteristics and load bearing capability; and movement of the passenger compartment due to localized buckling.
C. Application of the amendment to driver air bags.
In the NPRM, the agency noted a number of differences between the passenger and driver air bag problems. The agency explained that while the annual number of child fatalities is small but growing steadily, the annual number of driver fatalities does not appear to be growing. At the time of the NPRM, while the agency was aware of 18 children who had been fatally injured by air bags during 1996, it was aware of only one driver who had been fatally injured by an air bag in the United States during that year. (As of now, the agency is aware of 22 children, and three drivers, who were killed by air bags during 1996.)
The agency noted in the NPRM that 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 countermeasures to reduce the risk to out-of-position occupants. NHTSA requested information on the potential that current driver air bags have for creating adverse effects, including relevant design changes that have already been made to driver air bags.
D. Duration of amendment.
As indicated above, in developing the January 1997 proposal, NHTSA considered an array of approaches that would address the air bag safety problem. Among other things, the agency considered higher deployment thresholds, dual stage inflators, smart air bags, and various other air-bag related changes.
F. Benefits and trade-offs.
F. Specific sled test requirements/procedures.
1. Neck injury criteria
(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.
The source of the proposed neck injury criteria is "Anthropomorphic Dummies for Crash and Escape Systems," AGARD Conference Proceedings of NATO, July 1996, AGARD-AR-330. The agency noted that GM uses the same neck criteria for its injury assessment reference values (IARV's). Data provided by AAMA indicated that, in general, these neck criteria could not be met without an air bag. The agency requested comments on this subject.
2. Testing full vehicles or partial vehicles
AAMA, Subaru, and Volvo stated that manufacturers typically conduct partial vehicle tests. Nevertheless, AAMA stated that such sled tests could be conducted on either the full vehicle or partial vehicle. Similarly, Ford stated that "audit testing with an entire vehicle on a sled would be acceptable, even though vehicle manufacturers typically test with only the passenger compartment or the front portion of the passenger compartment." AVS and Morton stated that it is impracticable and infeasible to test the entire vehicle on the sled given a vehicle's weight and size.
4. Air bag activation
5. Test Attitude
6. Completion of sled test
G. Miscellaneous Issues.
1. Multistage manufacturer certification
2. Effective date
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 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.
B. Regulatory Flexibility Act
C. National Environmental Policy Act
D. Executive Order 12612 (Federalism) and Unfunded Mandates Act.
E. Civil Justice Reform
List of Subjects in 49 CFR Part 571
PART 571-FEDERAL MOTOR VEHICLE SAFETY STANDARDS
571.208 Standard No. 208, Occupant crash protection.
* * * * *
* * * * *
Sled pulse acceleration, expressed in G's = 17.2 Sin(t/125)
for delta V = 30(+0,-2) mph
Reference point | t (ms) |
Acceleration (G) |
---|---|---|
A | 0 | -2 |
B | 40 | -18.2 |
C | 85 | -18.2 |
D | 130 | 0 |
E | 5 | 0 |
F | 55 | -16 |
G | 70 | -16 |
H | 120 | 0.00 |
Issued on:
Ricardo Martinez
Administrator
Billing Code: 4910-59-P
[Signature page for RIN 2127-AG 59
(Final rule)]
1. Some State surveys are limited to passenger cars. The agency's latest National Occupant Protection Use Survey, a probability-based study of safety belt use in all vehicles types, indicates a current use rate of 58 percent. Another survey will be conducted in 1997.
2. The agency has examined air bag cases with children in its Fatal Analysis Reporting System (FARS) and identified no new cases. The agency believes these 38 cases are a census of all cases that have occurred and reported in FARS to February 15, 1997 involving fatalities. However, the information for adult fatalities does not represent a census. NHTSA updates air bag fatality information on a continuing basis. The information presented in this notice and accompanying Final Regulatory Evaluation generally reflects information available through February 15, 1997.
3. A fatality involving a 5 feet 4 inch female driver did occur in October 1996.
4. 4 At least 80 percent of each manufacturer's light trucks manufactured on or after September 1, 1997 and before September 1, 1998 must be equipped with an air bag and a manual lap/shoulder belt. Every light truck manufactured on or after September 1, 1998 must be so equipped.
5. 5 "Crash pulse" means the acceleration-time history of the occupant compartment of a vehicle during a crash. This is represented typically in terms of g's of acceleration plotted against time in milliseconds (1/1000 second). The crash pulse determines the test's stringency: an occupant will undergo greater forces if the crash pulse g's are higher at the peak, or if the duration of the crash pulse is shorter.
6. In States with "secondary" safety belt use laws, a motorist may be ticketed for such failure only if there is a separate basis for stopping the motorist, such as the violation of a separate traffic law. This hampers enforcement of the law. In States with primary laws, a citation can be issued solely because of failure to wear safety belts.
7. 7 NHTSA explained that the existing provisions of Standard No. 208 already provide 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.
8. 8 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.
9. 9 See pages III-45 and 46 of the PRE which show that the 143 millisecond pulse was significantly longer in duration and lower in amplitude when compared to the 125 msec pulse.
10. 10 The issue of whether to make this amendment temporary or permanent is discussed in detail below.
11. 11 NHTSA notes that concepts such as dual stage inflators are not new and were considered by the agency in deciding to require automatic protection. For example, in the early and mid-1970's, various vehicle manufacturers reported favorable results in testing the ability of various dual level or variable inflation systems for air bags to address the problem of out-of-position children. In 1980, NHTSA informed the industry about its analysis of a number of possible technological solutions, including dual-inflation air bags, chambering air bags and top-mounted air bags. The July 11, 1984 Final Regulatory Impact Analysis (FRIA) for the 1984 final rule requiring the installation of automatic occupant restraints in passenger cars (49 Fed. Reg. 28962; July 17, 1984) listed a variety of potential technological means for addressing the problem of injuries associated with air bag deployments (FRIA, pp. III-8 to 10): a dual level inflation system whose operation is based on impact speed; a dual level inflation system whose operation is based on a switch in the vehicle seat or elsewhere that measures occupant size or weight and senses whether an occupant is out of position; a dual level inflation system whose operation is based on an electronic proximity detector in the dashboard; and other technological measures such as bag shape and size, instrument panel contour, aspiration, and inflation technique.
12. Even if the use rates were significantly higher, and an analysis showed that dropping the unbelted test would have net safety benefits for motor vehicle occupants, the agency could not drop the test on its own initiative. As the agency noted in its February 27, 1997 notice, legislation would be necessary to authorize the agency to take that step.
13. Another difference accounting for the revised estimate of potential disbenefits relates to how the agency used barrier crash test results for baseline and depowered air bags. In the PRE, the agency applied the barrier crash test results to all potentially fatal frontal crashes. AAMA argued that barrier testing only represents about 10 percent of all fatal crashes, and that depowering will not have any effect in offset frontal crashes. AAMA argued that 10 percent of NHTSA's PRE disbenefit estimates would provide reasonable estimates. AAMA provided no data to show that there would be no effect of depowering on fatalities in offset frontal impacts. The agency's analysis indicates that barrier crashes are closely representative of about 34 percent of all fatal frontal crashes. The agency agrees that depowering may not have as much of an effect in offset frontal crashes, but the effect is unknown. For example, there is still a concern about a greater chance of an occupant's head hitting the A-pillar in an offset crash with a depowered air bag. The agency used a range in the FRE, applying the barrier test results to 34 to 100 percent of all frontal fatalities, to account for the fact that the agency does not know if depowering will have a smaller impact in those crashes for which barrier crashes are less representative.
14. 14 S8 specifies test conditions for vehicle loading, fuel system capacity, vehicle test attitude, seat location, and the status of doors and windows. The provision for vehicle test attitude references the "as delivered condition."