Air bags have been shown to be highly effective in saving lives. They reduce fatalities in frontal crashes by about 30 percent. As of June 1, 1998, air bags had saved an estimated 3,148 drivers and passengers since their introduction in 1986. However, as of that same date, the agency had confirmed a total of 105 crashes in this country in which an air bag deployment had resulted in fatal injuries.
These deaths did not occur at random; they typically involved certain common factors. The persons who have been killed or seriously injured by an air bag were extremely close to the air bag at the time of deployment. The persons shown to be at greatest risk have been (1) unrestrained young children, who can easily be propelled close to or against the passenger air bag before the crash as a result of pre-crash braking, (2) infants in rear facing child seats, who ride with their heads extremely close to the passenger air bag, and (3) drivers (especially unrestrained ones) who sit extremely close to the steering wheel. These drivers are most likely to be small-statured women.
Since the problem of air bag deaths first emerged, NHTSA has taken a number of steps to address the problem. In late November 1996, the agency announced that it would be implementing a comprehensive plan of rulemaking and other actions (e.g., consumer education and encouragement of State seat belt use laws providing for primary enforcement of their requirements) addressing the adverse effects of air bags.
Recognizing that a relatively long period of lead time is required to make some types of significant design changes to air bags, the agency's comprehensive plan called for both interim and longer-term solutions. The interim solutions included temporary adjustments in Standard No. 208's performance requirements to ensure that the vehicle manufacturers had maximum flexibility to address quickly the problem of risks from air bags. One temporary change was to permit manufacturers to certify their vehicles to an unbelted sled test option, in which a vehicle is essentially stopped quickly, but not actually crashed, instead of to the standard's full scale unbelted crash test, in which a vehicle is actually crashed into a barrier. This made it much easier for the manufacturers to make quick design changes to their air bags. Another temporary change was to permit the vehicle manufacturers to install manual on-off switches for passenger air bags in vehicles without rear seats or with rear seats that are too small to accommodate a rear facing child restraint.
Another interim measure taken by NHTSA was 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. Also, to address the problems faced by persons who are in groups at special risk from air bags, the agency issued a final rule exempting motor vehicle dealers and repair businesses from the statutory prohibition against making federally required safety equipment inoperative so that they may install retrofit manual on-off switches for air bags in vehicles owned or used by such persons and whose requests for switches have been approved by the agency.
In today's notice, NHTSA is proposing a longer-term solution. The proposed amendments contemplate implementation of advanced air bag system technology that would minimize or eliminate risks to out-of-position occupants and enhance the benefits provided by air bags to occupants of different sizes, belted and unbelted. The proposed amendments are consistent with the NHTSA Reauthorization Act of 1998, which requires advanced air bags.
In developing this proposal, the agency recognized that, to minimize or eliminate air bag risks, either (1) air bag deployment must be suppressed in situations that are risky to occupants, or (2) the air bag must be designed to deploy in such a manner that it does not present a significant risk of serious injury to out-of-position occupants.
The agency has used a number of methods to obtain up-to-date information regarding the technology needed for accomplishing these purposes. These methods included meetings with individual manufacturers, a public meeting and written information requests to vehicle and air bag manufacturers for specified types of information.
In numerous meetings with vehicle manufacturers and air bag suppliers, the agency discussed the steps that they were taking to address adverse effects of air bags. The agency found that these companies were working on a wide variety of technologies, involving one or both of the approaches (i.e., modulation of deployment or suppression of deployment) discussed above, to minimize or eliminate air bag risks. Vehicle manufacturers and suppliers are working on systems that would prevent an air bag from deploying in situations where it might have an adverse effect, using, for example, sensors that determine the weight, size, and/or location of the occupant. The vehicle manufacturers and suppliers are also working on systems that would modulate the speed and force of the air bag, using multiple level inflators. The activation of those different levels is keyed to sensors that determine such factors as crash severity, seat-track position, occupant weight and/or size, and whether an occupant is belted or not. They are also working on a variety of approaches that make air bags less aggressive to out-of-position occupants, e.g., by changing fold patterns, deployment paths, and venting systems.
NHTSA conducted a public meeting in February 1997 to obtain information about available technologies, and separately asked the National Aeronautics and Space Administration's Jet Propulsion Laboratory (JPL) for help in obtaining information. JPL surveyed the automotive industry and conducted an analysis of the readiness of advanced air bag technologies.
Also, in April 1998, the agency sent an information request concerning advanced air bag technology to nine air bag suppliers. This effort supplemented NHTSA's other efforts to obtain information in this area and was intended to ensure that the agency had the most up-to-date information possible for this rulemaking.
The agency considered the information obtained in these various endeavors, as well as other available information, in developing this proposal.
To minimize air bag risks, the proposed amendments specify alternative options that would allow use of the differing kinds of technological solutions being developed or considered by the manufacturers to effectively address this problem. For example, the agency is proposing options that would test the performance of air bags designed to inflate in a manner so they do not cause injuries. These options, which are based on an approach recommended by the American Automobile Manufacturers Association (AAMA), specify static out-of-position tests. The agency is proposing use of several child dummies (representing an infant, a 3-year-old, and a 6-year-old) and the Hybrid III 5th percentile adult female dummy in these tests. Injury criteria would be specified for each of the new dummies. The agency is also proposing options that would test the performance of systems designed to suppress air bag deployment in the presence of children and/or out-of-position occupants.
NHTSA believes the proposed amendments would permit the vehicle manufacturers to use any technology or design which can effectively address the problem of adverse effects of air bags to out-of-position occupants, without detracting from the ability of the vehicle to meet Standard No. 208's other occupant protection requirements. The design changes that can be used to meet the proposed requirements range from relatively simple changes in the way air bags deploy to advanced systems incorporating sensors which vary air bag deployment depending on the size, weight and dynamic position of an occupant and crash severity.
In addition to proposing requirements to address air bag risks to out-of-position occupants, NHTSA is proposing to add to the standard's dynamic frontal crash test requirements to ensure that improved protection is provided to teenagers and adults of different sizes, belted and unbelted, especially ones of smaller stature. Under Standard No. 208's longstanding dynamic crash requirements, vehicles must meet specified injury criteria, including ones for the head and chest, measured on 50th percentile adult male test dummies (both belted and unbelted) during rigid barrier crashes at any speed up to and including 48 km/h (30 mph) and at any angle up to ± 30 degrees.(2) Thus, manufacturers are required to assure compliance with occupant protection requirements in full scale vehicle crashes representing a wide range of severities and crash pulses that could potentially cause fatal injuries.
However, despite their compliance with requirements specifying the use of 50th percentile adult male dummies, some current air bags may not provide appropriate protection to small adult occupants. Most significantly, some designs do not take account of the special needs of occupants who must sit relatively close to the air bag, such as small-statured women drivers. In order to provide protection to someone who sits close to the air bag, an air bag must deploy early in a crash event. However, the air bags of some vehicles deploy late in certain kinds of crashes (such as ones with soft pulses), after a small-statured driver, even though belted, has struck the steering wheel. In such a situation, the air bag cannot provide protection and may cause harm. This same problem is faced by persons who sit close to the passenger-side air bag.
To address this problem, NHTSA is proposing to add new dynamic crash test requirements using 5th percentile adult female dummies. Protection would be required to be demonstrated in a new "offset deformable barrier crash test," a test which replicates a kind of real world crash likely to result in late deployment of many current air bags. This test measures the performance of the sensor system as well as the air bag in a 25-mph crash with a "soft" pulse, and would use restrained dummies only. In addition, 5th percentile adult female dummies would be added to the standard's existing 30-mph dynamic crash test requirements, using both restrained and unrestrained dummies.
The agency has developed injury criteria and seat positioning procedures that it believes are appropriate for small females. Among other things, the agency is including neck injury criteria, since persons close to the air bag at deployment are at greater risk of neck injury. NHTSA notes that it is also proposing to upgrade the current injury criteria specified for 50th percentile adult male dummies, and to add neck injury criteria, to make them consistent with what the agency is proposing for 5th percentile adult female dummies.
NHTSA recognizes that adding additional sizes of dummies would increase testing costs, but believes that their addition is needed to ensure that air bag performance is appropriate for occupants of different sizes. NHTSA notes that upgrading Standard No. 208 by adding a greater array of dummy sizes would parallel the agency's recent upgrading of Standard No. 213, Child Restraint Systems, through the addition of a greater array of sizes and weights of child test dummies.(3) Just as that final rule improved the safety of child restraint systems by providing for evaluation of performance in a more thorough manner, the addition of different size test dummies to Standard No. 208 would improve protection for all occupants by requiring more thorough evaluation of a vehicle's occupant protection system.
The agency notes that it may issue a separate document proposing to add the Hybrid III 95th percentile adult male dummy to Standard No. 208. With the addition of that dummy, occupant protection would be measured for adult occupant sizes ranging from small-statured females to large-statured males. The agency is not proposing to add the Hybrid III 95th percentile adult male dummy in this notice because development of that dummy has not yet reached the stage where it is appropriate for incorporation into a Federal motor vehicle safety standard.
NHTSA also notes that during calendar year 1999 it expects to propose a higher speed frontal offset requirement than that specified for the current barrier test. The agency is still conducting research regarding such a requirement. In addition, as more advanced technology is developed, the agency may develop proposals to require further enhancements in occupant protection under Standard No. 208.
To provide vehicle manufacturers sufficient time to complete development of advanced air bag designs meeting the new requirements proposed in today's notice, and implement them into their cars and light trucks, NHTSA is proposing a phase-in of the upgraded requirements beginning September 1, 2002, with full implementation required effective September 1, 2005. The agency is proposing to provide credits for early compliance with the rule. To address the special problems faced by limited line manufacturers in complying with phase-ins, the agency is proposing to permit manufacturers which produce two or fewer carlines(4) the option of omitting the first year of the phase-in if they achieve full compliance effective September 1, 2003.
NHTSA notes that Standard No. 208 contains several provisions, noted above, that were added as temporary measures to address air bag risks. One is the provision permitting manufacturers to provide manual on-off switches for passenger air bags in vehicles without rear seats or with rear seats too small to accommodate a rear facing infant seat. It expires on September 1, 2000.
The other is the provision permitting certification based on the unbelted sled test alternative to the unbelted barrier test requirements. It was scheduled to expire on September 1, 2001. However, notwithstanding the expiration date currently specified in the standard for the unbelted sled test option, the NHTSA Reauthorization Act of 1998 provides that the sled test option "shall remain in effect unless and until changed by [the final rule for advanced air bags]." The Conference Report states that the current sled test certification option remains in effect "unless and until phased out according to the schedule in the final rule."
In this notice, the agency is proposing to amend Standard No. 208 so that both the sled test option and the manual on-off switch provision are phased out as the new requirements for advanced air bags are phased in. During the phase-in, the sled test option and manual cutoff provision would not apply to any vehicles certified to the upgraded requirements, but would be available for vehicles not so certified under the same conditions as they are currently available. Thus, as manufacturers develop advanced air bags, they would need to ensure that vehicles equipped with these devices meet all of Standard No. 208's longstanding performance requirements as well as the new ones being proposed today.
The agency is similarly proposing to amend its regulation permitting the installation of retrofit on-off switches to specify that these devices cannot be installed in vehicles that have been certified to the new requirements for advanced air bags.
NHTSA notes that, as discussed later in this notice, the auto industry and other commenters have raised a number of objections to the existing unbelted barrier test requirements.(5) While the agency is not proposing alternatives to those requirements in this notice, it is requesting comments on whether it should develop alternative unbelted crash test requirements.
This notice also provides the agency's response to all outstanding petitions concerning air bag performance.
