Final Economic Assessment

 

FMVSS NO. 208
AIR BAG ON-OFF SWITCHES

 

Office of Regulatory Analysis and Evaluation
Plans and Policy
November 1997

 


TABLE OF CONTENTS

SUMMARY

INTRODUCTION

BACKGROUND

SUMMARY OF COMMENTS

THE FINAL RULE

POTENTIAL SAFETY IMPACTS

COSTS

SMALL BUSINESS IMPACTS


SUMMARY

This Final Regulatory Evaluation analyzes the potential impact of allowing motor vehicle dealers and repair businesses to install air bag on-off switches in vehicles. This option is being considered in response to concerns that current air bags may injure or kill some occupants in low speed crashes.

Data indicate that only a small portion of vehicle occupants are actually at risk of fatal harm from air bags, and these occupants tend to fall into well-defined groups. Because both the actual risk and the public's perception of this risk are quite different for drivers and passengers, this analysis addresses this issue separately for each occupant position.

On-off switches are unlikely to be necessary after advanced air bags become available. Vehicle manufacturers are expected to install some kind of advanced air bags on a high proportion of their fleets by the year 2002. An analysis was therefore performed of the impacts that might occur during the 1998-2001 period, when an average of 45% of the on-road vehicle fleet will have driver side air bags, and 32% will have passenger side air bags. Safety impacts will continue to occur over the remaining life of these pre-2002 model year fleets, but at a declining rate as more vehicles are retired from the fleet without being replaced by vehicles with on-off switches. For purposes of isolating and analyzing the impacts of this rulemaking, it is assumed that there is no change in air bag design (i.e., the potential impact of depowering or other air bag design improvements are not included). It is also assumed that there is no change in driver/passenger behavior, belt use, child restraint use, or the percent of children sitting in the front seat. Since the agency has education and labeling efforts underway, and the manufacturers are constantly improving air bags, the population at risk from the adverse effects of air bags should be considered a worst case scenario, and the population that could be positively affected by on-off switches will actually be smaller than assumed for the purpose of this analysis. The results of this analysis are as follows:

Drivers

If on-off switches are installed and used by all drivers actually at risk, the switches could prevent 45 fatalities during the 1998-2001 period, an average of 11 each year. For every one percent of those in the not-at-risk group who use on-off switches, the number of drivers saved by air bags could be reduced by 42 for that period, an average of 11 drivers each year. Nonfatal injuries impact a broad range of occupants and risk groups cannot be properly identified.(1) For each one percent of drivers that use on-off switches, the number of moderate to critical injuries saved by air bags could be reduced by 490 during 1998-2001 (123 annually).(2)

Passengers

Passenger impacts vary dramatically by age group. If on-off switches are installed and used for all child passengers (ages 0-12), they could prevent 177 deaths over the 1998-2001 period, an average of 44 deaths annually. The net impact of on-off switches on nonfatal injuries is uncertain, but the agency believes that on-off switches would provide a net benefit to children.

The agency cannot identify the teenage and adult passenger at-risk group, with the exception of a minimal number of medical cases. The agency advises all those passengers above 12 years of age to leave air bags on. For every one percent of teenage and adult passengers who utilize on-off switches, the potential benefits of air bags could be reduced by 9 fatalities and 93 moderate to critical injuries during the 1998-2001 period, an average of 2 fatalities and 23 injuries annually.

Costs

NHTSA estimates that an on-off switch for one seating position would cost between $38 and $63 installed and that the cost for an on-off switch to control both the driver and right front passenger air bags would cost between $51 and $76 (1996 dollars) installed on aftermarket vehicles (only a small fraction of vehicle owners "qualifying" for on-off switches would "qualify" for a switch that controls both driver and passenger air bags). These costs would be voluntary and incurred at the initiative of the vehicle owner. Ford was the only commenter on costs. Ford estimated the cost of installing an aftermarket on-off switch that controls both the driver and right front passenger air bag to be $95 to $124. NHTSA's cost estimate is lower because it assumes less time to install the switch and a nationwide average labor rate that is lower than the rate assumed by Ford.

INTRODUCTION

In the Intermodal Surface Transportation Efficiency Act of 1991 (ISTEA), Congress directed NHTSA to amend Federal Motor Vehicle Safety Standard (FMVSS) 208 to require all passenger cars and light trucks to provide automatic occupant protection by means of air bags. The Act required at least 95 percent of each manufacturer's passenger cars manufactured on or after September 1, 1996, and before September 1, 1997, to be equipped with an air bag at both the driver's and right front passenger's seating positions. Every passenger car manufactured on or after September 1, 1997, must be so equipped. The same basic requirements are phased in for light trucks one year later, starting at 80 percent on September 1, 1997, and 100 percent on September 1, 1998.

In addition, all fifty states and the District of Columbia require the use of child safety seats. The agency recommends that newborn children be secured in a rear-facing child restraint system and placed in the back seat of the vehicle. Agency testing in 1991 showed that placing a rear-facing safety seat in the front seat of a vehicle equipped with a passenger-side air bag was very dangerous for the infant.

Crash data have verified that air bags can cause serious injuries and fatalities to rear-facing infants. Crash data have also shown that children, mostly unbelted but in some cases belted children, can be seriously or fatally injured by an air bag. The agency recommends that all children 12 and under should sit properly restrained in the back seat of vehicles.

Adult occupants, almost all of them drivers, have also suffered fatal and non-fatal injuries from air bag deployments. Fatalities have resulted from being too close to the air bag when it deploys. Air bags have also caused non-fatal injuries to adult occupants. However, air bags provide a significant net benefit to adult occupants in preventing fatal and serious non-fatal injuries.

On January 6, 1997, the agency published in the Federal Register a Notice of Proposed Rulemaking (NPRM) on Air Bag Deactivation, appearing in Docket No. 74-14, Notice 107. As part of its efforts to address the problem of the adverse effects of current air bag designs on children and certain adults, NHTSA proposed to allow dealers and repair businesses, upon written authorization of a vehicle owner, to deactivate either the passenger-side air bag, the driver-side air bag, or both. In order to qualify for exemption from the statutory prohibition against making required safety equipment inoperative, the dealer or repair business would be required to provide the owner with a NHTSA information sheet describing the circumstances in which deactivation may be appropriate, based upon the comparison of the risks of turning the air bag off versus leaving it on in those circumstances.

The NPRM also stated that air bag deactivation would not be permitted if the vehicle were equipped with a manual on-off switch for the air bag or if the air bag were one that contained advanced technology that controlled deployment levels.

The agency requested comments as to the appropriateness of this proposal and asked a number of questions pertaining to the determination of who should be permitted to have their air bags deactivated and who would be responsible for that determination. Questions were also posed regarding the retrofit of on-off switches and other methods of turning off air bags. For this analysis, deactivation means a method of turning off an air bag (such as cutting wires, pulling fuses, adding a device under the dash that turns the air bag off, etc.) that cannot be easily/readily turned back on by the consumer. An on-off switch is a device that can be readily turned off or on by the occupant using a key and turning the switch.

This Final Regulatory Evaluation (FRE) examines the benefits and disbenefits of on-off switches. Due to the public reaction to those incidents that have resulted in air bag related fatalities, the agency is concerned that there could be a significant percentage of the population that may be interested in turning off their air bags. If a large number of drivers who are not at risk, but nevertheless, turn off their air bags to guarantee that they are not one of the 11 people that could potentially be killed annually by air bags during the 1998-2001 period, there would be a rise in fatalities and serious injuries.

NHTSA will continue to educate and inform the public of the safety tradeoffs that result from disconnecting air bags, and to help prevent drivers that are not at risk from air bags from using on-off switches.

The analysis will discuss: 1) the circumstances under which deactivation should be considered; 2) the safety tradeoffs of such an action; and 3) the cost of available technology for deactivation.

BACKGROUND

While it is estimated that air bags have saved 2,620 lives through November 1, 1997, they can pose a danger to infants in rear-facing child seats and to some other occupants, primarily unbelted children, in low-speed collisions. When all passenger cars and light trucks and vans have air bags (assuming current designs and not considering the impacts of depowering or other potential improvements to air bags), air bags would save the lives of an estimated 2,327 drivers and 721 passengers annually. The right front passenger numbers do not include estimates of the number of children's lives saved by air bags. If there is no change in air bag design, driver/passenger behavior, belt use, or the percent of children sitting in the front seat, and air bags were in all passenger cars and light trucks and vans, NHTSA estimates there could annually be 140 children killed by air bags (33 in rear facing infant seats and 107 older children), 25 drivers and 7 adult passengers killed by air bags. These estimates should be considered a worst case scenario since the agency has education efforts underway and has already completed several rulemakings on the issue.

The agency has conducted a series of rulemaking proceedings over the last four years to address the risks posed by air bags. Most recently, the agency issued three final rules on this issue. One required new, attention-getting warning labels for child restraints and for vehicles without a "smart" passenger air bag, i.e., an air bag that automatically shuts off or adjusts its deployment so as not to adversely affect children. The second final rule extended the period during which manufacturers may install manual on-off switches for passenger air bags in vehicles lacking a rear seat that can accommodate child restraints. In addition, the agency issued a final rule allowing a temporary amendment to Standard No. 208 to facilitate a 20 to 35 percent depowering of current air bags. Depowering will be phased-in rapidly beginning with the MY 1998 fleet. Depowering will reduce the potential inflation induced injuries from air bag deployments in low speed crashes. The potential impacts of depowering have not been included in the calculations for the 1998-2001 time period.

The NPRM addressed the issues of statutory authority to permit deactivation, the comments addressing deactivation received in response to the agency's August 1996 NPRM, and the granting of exemptions from state safety belt use laws for medical and psychological reasons. Comments were submitted to the docket on the January 6, 1997, NPRM covering these and other issues.

SUMMARY OF COMMENTS

There were approximately 700 comments on the NPRM. About 600 of those were from members of the general public. The rest were from companies or trade associations representing vehicle manufacturers, dealers and repair businesses, fleet managers and owners, equipment manufacturers, consumer safety groups, insurance companies, physicians and health-related groups, former NHTSA administrators, and miscellaneous other organized groups. Because so many commenters took the same or similar positions on the issues, the commenters are not identified in this preamble unless there is some special significance to their identity. Instead, they are referred to simply as "general public" commenters and "company and group" commenters (even if some of the "company and group" comments are from individual companies).

The general public commenters supported, and the company and group commenters did not oppose, the agency's exempting dealers and repair businesses from the make inoperative prohibition so that air bags could be turned off. However, the commenters were divided on many of the details of how this should be accomplished and on the breadth of the exemption.

Almost all commenters supported deactivation as a means for turning off air bags. Most of the companies and groups also supported permitting retrofit on-off switches at least as an alternative to deactivation. GM, a dealer's group, a service group, and a number of safety groups went further, stating that on-off switches should be the only permitted way of turning off an air bag. About one in six of the general public commenters also stated that on-off switches should be installed in lieu of, or as a preferred means of, turning off air bags. The Insurance Institute for Highway Safety (IIHS), which supported deactivation, stated that it reluctantly supported on-off switches as well. Its reluctance arose in large part from the amount of apparent interest in on-off switches. Based on a January 1997 public opinion survey that it commissioned showing a strong public preference for on-off switches over deactivation, IIHS suggested that more people would choose to have on-off switches installed than would have deactivations performed. A few commenters opposed on-off switches. BMW stated that on-off switches should not be allowed because their development will divert resources from development of advanced air bags, conflict with the decision not to require them on new vehicles, and introduce complexity for service and repair, compared with the "simple reprogramming" necessary for temporary deactivation of its air bags. Both BMW and IIHS expressed concern that allowing on-off switches would encourage placing children in front where the risk of serious injury is greater, with or without air bags. Most company and group commenters thought that on-off switch misuse would be a significant problem.

The issues which drew the most comments were "who should be allowed to have their air bags deactivated, and under what procedure?"(3) The general public commenters almost universally favored allowing air bag deactivation for anyone who wants it, i.e., regardless of whether a person is actually in a risk group. Both the National Transportation Safety Board (NTSB) and IIHS also supported deactivation for vehicle owners who want it, i.e., without requiring membership in a risk group. In addition, one equipment manufacturer, and three groups supported deactivation for owners who want it and based their support on personal liberty arguments. However, most of the other company and group commenters were opposed to deactivation for everyone who wants it.

The main argument given by the general public commenters for broad availability of deactivation was that there should be personal choice as to whether to turn one's air bag on or off. These commenters emphasized the danger that they believe air bags pose and many mentioned media reports that they had seen. They frequently noted that there were circumstances that they believed would tend to put them or their family members at risk. Generally, these circumstances included short stature, pregnancy, being elderly, needing to transport children, and certain medical conditions. Many stated that they wore their seat belts, and that they believed that the air bags were of marginal benefit.

IIHS said that it supported broad availability because of the apparent extent of public interest in turning off air bags for at least some vehicle occupants. The organization suggested that trying to limit the availability of deactivation would create an adverse public reaction. In support of this suggestion, IIHS cited its January 1997 survey indicating that 30 percent of their respondents would like an on-off switch for the driver air bag, and 67 percent would like one for the passenger air bag. Thirteen percent said they would like a permanent deactivation of the driver air bag, and 19 percent wanted permanent deactivation for the passenger air bag.

The main argument of the company and group commenters against relying on informed decisionmaking in allowing deactivation was that there would be widespread deactivation by frightened and misinformed consumers who were not actually at risk. Many company and group commenters expressed concern that the issues relating to air bag risks might be too complex for the general public to comprehend so that it would be difficult for the public to make informed decisions. Some commented that allowing deactivation for everyone would even encourage deactivations by implying that air bags were so dangerous that they generally should be disconnected. The great majority of company and group commenters favored a continuation of NHTSA's current practice of authorizing deactivations only in limited circumstances and solely on a case-by-case basis. In August 1997, a broad coalition of vehicle manufacturers, dealers, insurers, public interest groups, medical societies and others met first with the Office of Management and Budget and later with NHTSA to reiterate the comments they made in February of this year in support of limiting eligibility under the exemption to persons in risk groups identified by the agency and requiring the agency to approve each request for an on-off switch before a switch can be installed.

Several individual vehicle manufacturers, and the industry associations representing all domestic and foreign vehicle manufacturers, said that NHTSA does not have the statutory authority to allow deactivation based on informed decisionmaking. General Motors (GM) argued that the proposal did not meet the three tests which it believes are implicit in the statute: (1) an exemption must be for a single individual, not classes of people; (2) an exemption for a specific individual must be based on the agency's judgment, not the individual's judgment; and (3) an exemption must be consistent with vehicle safety. These commenters noted that the agency emphasized in the NPRM that only in limited instances would deactivation be, on balance, in the best interests of a driver or passenger. They argued that the predicted widespread deactivations provided to anyone who wanted one would result in more people being killed and injured in situations in which the air bag might have saved them, thus resulting in a reduction of motor vehicle safety. Finally, Ford argued that the agency's desire for administrative simplicity does not overcome the necessity for complying with the statute.

The company and group commenters advanced a number of safety arguments against allowing deactivation based on informed decisionmaking. Some of them suggested that depowering air bags would obviate the need for a broad availability of deactivation. Several stated that occupant restraint systems are integrated. Seat belts designed to work with air bags may not work so well as conventional seat belts if the air bags are deactivated. In particular, it was stated that, depending on how it was performed, deactivating the air bag could also deactivate seat belt pretensioners that use the same crash sensors as the air bag. GM suggested that it is the safety conscious people who already buckle themselves and their children who will tend to deactivate their air bags in reaction to media reports of air bag deaths and injuries. Because people who wear belts are seldom harmed by air bags, GM concluded that, ironically, many or most who disconnect will be at increased risk. A majority of the company and group commenters stated that vehicles with deactivated air bags would be sold to other parties who might not know of the deactivation, or in the case of vehicles with retrofit on-off switches, might misuse the on-off switch.

The company and group commenters almost universally stated that deactivation was, given its permanency, appropriate only in rare circumstances. Most of these commenters did not identify those circumstances, but stated that NHTSA should determine the proper categories of persons who would be better off without the air bag, based on its expertise and data. To the extent that the circumstances were noted, they are discussed briefly below.

There was universal agreement that certain young children riding in the front need to be protected from the risk of serious injury from air bags. Nearly all commenters said that owners and lessees who own vehicles lacking a seat capable of accommodating a rear-facing infant restraint and who need to transport infants in such restraints should be able to have the passenger air bag deactivated. Some commenters suggested that air bags should be turned off for young children with medical conditions that need frequent monitoring by the driver. In contrast, the American Academy of Pediatrics stated that situations in which a child needs immediate attention are very rare, and that it was more dangerous to attend to them while driving. Another circumstance suggested by some commenters is the presence of too many children in a vehicle to place all of them in the back seat.

Other categories mentioned by some of the commenters include people of short stature, the elderly, and people with certain medical conditions or disabilities. These categories were also mentioned extensively in the general public comments. However, the company and group commenters tended to minimize the risk to these categories of people. They generally did not include the elderly as a category, and some of them suggested that exemptions for medical reasons should be accompanied by a doctor's note. One safety group suggested NHTSA employ a licensed medical professional or panel to examine requests. One medical group suggested that NHTSA and a panel of medical professionals define qualifying medical conditions. While some commenters agreed that short people were in danger, they emphasized the difficulty of determining how short was too short.

More recent submissions and statements from the company and group commenters argue that the issue is not height, but sitting distance from the air bag module. IIHS submitted a survey indicating that only 5 percent of female drivers (approximately 2.5 percent of all drivers) are accustomed to sitting within 10 inches of their air bag module. Of those 5 percent of female drivers, 66 percent normally sit 9-10 inches from their air bag, and an additional 17 percent normally sit 8-9 inches away. The remainder, accounting for less than 1 percent of female drivers, normally sit within 8 inches of their air bag.

IIHS also found that a high percentage of short-statured female drivers could adjust their driving position to achieve a 10-inch distance. This finding was based on 13 women, from 4 feet, 8 inches tall to 5 feet, 2 inches tall, who were asked to try to achieve that distance in a dozen vehicles of varying sizes. Ten of the women achieved 10 inches so in all of the vehicles; the remaining 3 did so in all but a few of the vehicles. All drivers were able to achieve at least 9 inches in all vehicles.

Other reasons given for not allowing deactivation based on informed decisionmaking were assertions that NHTSA's current system of case-by-case determinations was believed to work well and only needed unspecified streamlining; that the few deactivation requests NHTSA received until recently proved that actual need was low; and that the authorization form would be ineffective, especially with respect to subsequent purchasers of vehicles with deactivated air bags, as a means of alleviating the liability concerns of the manufacturer, dealer, and repair business groups. In an August 1, 1997 letter, a broad coalition of company and group commenters argued that since the agency was reportedly answering all deactivation requests within 72 hours and had no backlog of unanswered requests, the agency should be able under the final rule to continue its current practice of reviewing and approving each deactivation request.

In addition to objecting generally to the proposal for deactivation based on informed decisionmaking, many of the company and group commenters expressed concerns about particular aspects of the proposed process for implementing the exemption from the make inoperative prohibition. The dealer and repair business groups, and generally also the vehicle manufacturers and safety groups, were opposed to the dealers having any role in the process of distributing information brochures or making any kind of decision in the process. They indicated that it would be difficult to reject the request of an owner who wanted deactivation or advice on whether to deactivate, yet the dealers did not have the expertise to advise owners on deactivation. Dealer and vehicle manufacturer groups also stated that the existing definition of advanced air bags was too vague and that a dealer could not be expected to determine whether a vehicle was equipped with one, and therefore ineligible for deactivation.

Some of the company and group commenters stated that NHTSA should require guidance from the vehicle manufacturers on how to perform deactivations. A dealers' group commented that if NHTSA did not require the vehicle manufacturers to provide procedures, dealers/repairers might perform improper repairs, and that deactivations should be done only by factory trained and certified deactivation technicians at a franchised dealership. Two manufacturers suggested that NHTSA require manufacturers to provide such procedures, and one suggested requiring deactivation kits. Ford commented that NHTSA should require deactivation to be done in accordance with "manufacturer recommendations."

A large majority of company and group commenters also stated that any recordkeeping under the exemption from the make inoperative prohibition should be done by NHTSA. Vehicle manufacturers uniformly stated that NHTSA should keep the records because the agency could provide a centralized information clearinghouse on air bag deactivations. Vehicle manufacturers also commented that since they have no role in authorizing or performing deactivations, or in enforcement, they should not have recordkeeping responsibilities. Multinational Business Services (MBS) stated that the agency should be the record keeper so that it could analyze trends among the requests for deactivation and make any appropriate policy adjustments. The insurance and safety groups suggested that NHTSA notify insurers of any deactivations, because permanent deactivation would eliminate the basis for the air-bag discount many insurance companies offer. GM suggested that recordkeeping would be totally unnecessary if on-off switches were installed.

Many of the company and group commenters opposed an immediate effective date. Jaguar suggested at least 60 days would be needed for label printing, software development, preparations of procedures for disconnect/reconnect, and training. Other manufacturers, who urged that retrofit on-off switches be allowed as an alternative to permanent deactivation, stated that additional time would be needed for development of on-off switches. Ford said that it would need 5 - 6 months to have a large supply of retrofit on-off switch kits in dealer inventory. In an August 29, 1997 meeting with agency representatives, a broad coalition of company and group commenters urged that adequate leadtime be provided to give the government as well as many of the company and group commenters sufficient opportunity to communicate their safety messages about air bag safety and risks to the public.

Opinion about sunsetting (i.e., terminating) the exemption was divided. GM opposed sunsetting the exemption when "smart air bag," i.e., advanced air bags, are introduced. The company said that until the term can be adequately defined, NHTSA should remove the term from the rule, along with any sunsetting associated with it. Advocates for Highway and Auto Safety commented that sunsetting the exemption was appropriate.

Some company and group commenters discussed the costs associated with deactivation. Some manufacturers merely stated that additional parts and extensive labor would be required for both deactivation and reactivation. Only Ford gave specific cost estimates. Ford estimates for parts and labor (but not including profit) ranged from $16 for a simple shorting bar removal, to $124 for an on-off switch. The NTSB commented that some manufacturers had indicated to it that the cost of on-off switches would be $300-400 per on-off switch. Some insurance groups indicated that insurers might eliminate the air bag discount, even with on-off switches, because they would be unable to identify deactivated vehicles. This would penalize those who do not disconnect.

IIHS submitted a July 1997 report in which that organization concluded the results of 40 mph offset frontal crash tests demonstrate that turning off an air bag increases the risk that a belted driver will be seriously injured in a crash. Crash tests using dummies representing an average size male driver indicated that without an air bag, the safety belts alone would not have prevented a belted driver from suffering "life-threatening" head and neck injuries. Similarly, another July 1997 IIHS report concerning 35 mph barrier crash tests with 5th percentile female dummies indicated that short-statured women can obtain significant protection from an air bag even when the driver's seat is moved all the way forward. The tests indicated that without air bags to spread the crash forces over the entire head, the crash forces would instead be concentrated on a narrow portion of the middle or lower portions of the face where the bones are more fragile. IIHS noted that a study of 15 restrained drivers fatally injured in frontal crashes with head injuries of AIS 4 or greater, found that steering wheels were the sources of head injuries for 9 of these drivers, and that 13 drivers suffered their head injuries from loading to the facial bones.

Some company and group commenters addressed the adverse effect of turning off air bags on the performance of some seat belts designed to work with air bags. A wide variety of companies and groups commented that, whatever the method of deactivation, it should be done in a manner that facilitates reactivation. All commenters who addressed the question stated that the air bag readiness indicator should have to remain functional for the remaining air bag, even if one air bag were deactivated. The companies and groups also generally commented that if both air bags have on-off switches, the air bags should be individually controllable.

Nearly all company and group commenters emphasized the importance of an informed decision by individual members of the public about deactivation. Many said improvements were needed in the proposed information brochure. The most common assessment was that the information brochure was too long and technical. Others commented that NHTSA should focus-group test the effectiveness of these documents prior to distributing them. Several suggested that the information be provided in a brochure or a video.

Many company and group commenters argued that the agency significantly underestimated the number of people who would seek deactivation under the proposal. Many commenters argued that the agency should consider public opinion surveys in making a new estimate. One commenter urged the agency to base its estimates on the IIHS' January 1997 survey. The most recent survey, an August 1997 survey from IIHS, indicated that 12 percent of vehicle owners were interested in obtaining an on-off switch for the driver's air bag and 16 percent for the passenger's air bag. Based on early 1997 surveys, that commenter contended that the proposal would have significant net adverse effects on safety. In an August 1, 1997 letter, the vehicle manufacturers argued that the net effects must be assessed in order to ensure that the exemption meets the statutory criterion of consistency with safety.

THE FINAL RULE

This final rule exempts, under certain conditions, motor vehicle dealers and repair businesses from the "make inoperative" prohibition in 49 U.S.C. 30122 by allowing them to install retrofit manual on-off switches for air bags in vehicles owned by people who provide the dealer with an authorization letter signed by NHTSA. In order to obtain an authorization letter signed by NHTSA, they must submit to NHTSA a request form that certifies that they have read an information brochure describing the risk trade-offs that may occur from shutting off the air bag and that they, or a user of their vehicle, are a member of one or more specified risk groups. The purpose of an exemption permitting installation of on-off switches is to preserve the benefits of air bags while reducing the risk to some people of being seriously or fatally injured by current air bags in limited circumstances.

Although the agency still believes that it is appropriate to exclude vehicles with advanced air bags from the exemption, it has not done so in this final rule. It is not necessary to do so yet since widespread introduction of advanced air bags is not expected during the next several years. This will give the agency time to develop an improved definition of "advanced air bag" and to address how dealers and repair businesses will be able to ascertain whether a particular vehicle has advanced air bags.

The agency has decided not only to permit retrofit on-off switches, but to specify that they will be the only means permissible under the exemption for turning off an air bag.(4) The agency has made that choice because on-off switches are a more flexible and focused solution than deactivation to the risks which air bags may pose to certain people and thus are significantly more consistent with safety than deactivation. With retrofit on-off switches, air bags can be left on for the vast majority of the persons who will benefit from air bag protection and turned off for the relatively few persons at risk. By contrast, deactivation is essentially permanent and makes no distinction between vehicle users who are at risk from air bags and those who are not at risk from air bags and who will benefit substantially from them.

Under the exemption, vehicle owners can obtain a retrofit on-off switch from a dealer or repair business after filling out and submitting a written request form to NHTSA, and receiving a signed authorization letter for this procedure. To promote the making of informed decisions about obtaining and using on-off switches, consumers must certify on the form that they have read an agency information brochure providing guidance about the risks created by current air bags and discussing the circumstances in which it may be appropriate to use on-off switches to turn off air bags. The requirement for this certification is intended to encourage persons considering on-off switches to focus on the factors that create risk from air bags and to reflect on whether they or their passengers are really at risk. Owners must also certify that they or another user of their vehicle are a member of one of the particular risk groups identified by the agency. Since the risk groups for drivers are different from those for passengers, a separate certification must be made for each air bag to be equipped with an on-off switch.

The agency strongly urges caution in obtaining and using on-off switches to turn off air bags. While on-off switches may be needed by a limited number of people in particular circumstances, they are not needed for the vast majority of people since they are not in a risk group. In fact, if people not at risk were to turn off their air bags, they would be less safe, not more safe. Even those people in a risk group can take steps that will eliminate or significantly reduce any risk they might currently have without going to the extreme of turning off their air bag and losing its protective value. The easiest way of eliminating the risk for children is to place them in the back seat and buckle them up.(5) Those drivers who are at risk can eliminate that risk by using their seat belts and by moving the driver's seat rearward and/or tilting the back of the driver's seat so that there is 10 inches or almost 10 inches between the center of their chest and the center of the

driver air bag. The primary risk of injury occurs 2-3 inches from the air bag cover because that is where the force of a deploying air bag is greatest.(6)

This exemption will be subject to certain conditions to promote the safe use of on-off switches. Each on-off switch must meet certain performance criteria similar to those applicable to the manual on-off switches that vehicle manufacturers may currently install for passenger air bags in new vehicles without a rear seat capable of accommodating a rear-facing infant seat. One is that the on-off switch be operable by a key. Another is that there be a telltale light to indicate to vehicle occupants whether an air bag equipped with an on-off switch is on or off. As a reminder about the proper use of on-off switches, the agency is requiring that vehicle dealers and repair

businesses give owners an owner's manual insert describing the operation of the on-off switch, listing the risk groups, stating that the on-off switch should be used to turn off an air bag for risk group members only, and stating the safety consequences of using the on-off switch for a person who is not in any risk group.(7)

Vehicle manufacturers and aftermarket parts manufacturers may make on-off switches available for any vehicle make or model. NHTSA expects that vehicle manufacturers will make on-off switches available for the majority of vehicle makes and models. The agency will continue to consider deactivation requests after on-off switches can be installed only for vehicles for which retrofit on-off switches are not available from the vehicle manufacturer. If aftermarket parts manufacturers make on-off switches available for any of those vehicles, these switches could be used by motor vehicle dealers and repair businesses.

POTENTIAL SAFETY IMPACTS

The impact of an air bag on-off switch on safety will be largely a function of the portion of vehicle owners who elect to install and use on-off switches. The agency has identified two groups of persons who the agency believes are definitely better off with the air bag turned off: 1) infants in rear facing restraints and 2) drivers or passengers with unusual medical or physical conditions. The agency has also identified two groups that may be better off using an air bag on-off switch: 1) children that are 12 years old or younger and 2) drivers who cannot or will not sit 10 inches away from the steering wheel.

NHTSA notes that the risk from the air bag for rear-facing infants can be entirely eliminated by restraining the infant in the back seat. However, infants might need to be carried in the front seat, either because there is no rear seat or the rear seat is too small to accommodate an infant seat, or because the infant needs to be monitored because of special medical reasons. In this situation, an on-off switch should definitely be used, and will result in safety benefits.

Similarly, the risk for passengers with medical conditions or children that are 12 years old or younger can be eliminated by restraining them in the back seat. However, if an on-off switch is not available and a child 1-12 must ride in the front seat because there are too many other children in the back seat, the risks from the air bag can be minimized by ensuring that the child is properly positioned, remains properly restrained during the ride, and the front seat is moved all the way back away from the air bag.

For drivers, the risk can be reduced by sitting as far away from the air bag as possible and still being able to comfortably control the vehicle.

NHTSA believes that the vast majority of the motoring public, i.e., those not in the four categories mentioned above, are clearly better off with air bags turned on. For these persons, use of an on-off switch would result in negative safety impacts.

Estimated Levels of On-off Acquisition

The Insurance Institute for Highway Safety submitted the results of a survey of public attitudes about air bags (Docket 74-14-N107-657) taken in January 1997. The IIHS survey suggests that 30 percent of respondents wanted on-off switches for the driver air bag, and 13 percent wanted to have the system completely disconnected. For the passenger side, 67 percent wanted on-off switches and 19 percent wanted the air bag disconnected. A survey conducted by the Harvard Center for Risk Analysis in late February/early March 1997 found similar results. In the Harvard study, 33 percent of respondents indicated a desire to turn off the air bag on some trips, and 16.7 percent said they would leave it disconnected all the time.

These surveys indicate a significant level of public interest in on-off switches. However, for several reasons, NHTSA believes that these surveys cannot be taken as indicative of actual consumer response:

There are other reasons for questioning the results of the January 1997 IIHS and Harvard surveys as a basis for predicting how many people will obtain on-off switches for turning off their air bags. In asking the respondents whether they wanted on-off switches, the surveyors did not ask whether the respondents were aware of a number of key factors that could heavily influence the extent of their desire for an on-off switch. Further, the surveyors did not take the alternative approach of informing the respondents of these factors and then asking them whether learning any or all of the matters influenced their desire for a switch. Three undiscussed factors in particular seem key: (1) most people would be making significant safety tradeoffs if they turned off their air bags; (2) most people could control and virtually eliminate the risk of serious air bag injuries by changing their driving and riding habits instead of physically changing their vehicle; and (3) the cost of an on-off switch is not insubstantial.

In early August, 1997, IIHS again conducted a survey of public attitudes on air bags (Docket 74-14-N107-686). This time they added questions pertaining to cost and included statements regarding the risk trade-offs inherent in disconnecting air bags, as well as on other methods of reducing the risk of air bag caused injury such as wearing restraints and sitting at least 10 inches from the steering wheel. The results of the survey indicated that 27 percent of respondents initially expressed an interest in disconnecting the driver air bag and 26 percent wanted to disconnect the passenger side air bag. After the issues of cost and risk were raised, the portion interested in disconnecting the air bag dropped to 12 percent on the driver's side, and 16 percent on the passenger side.

The more recent IIHS survey is an improvement over the previous surveys because it addresses issues of cost and education. Survey respondents were told that sitting at least 10 inches away from the air bag and always wearing a safety belt would virtually eliminate the risk of serious injury from the driver air bag. However, the respondents did not have a chance to measure their actual distance and might have misjudged how far away from the air bag they actually sit. Nevertheless, the dramatic decrease in the portion of respondents that were interested in disconnecting the air bag after cost and safety issues were raised illustrates the importance of these issues and the potential for further reductions if additional efforts are made to educate the public regarding the safety of air bags.

As of August 15, 1997, 10,300 people have written to NHTSA requesting permission to deactivate their air bag(s). Letters are currently arriving at a rate of 15,000 per year. Actual experience thus contrasts sharply with the opinions expressed in public surveys. This makes selection of a probable rate of on-off switch acquisition highly uncertain. However, NHTSA believes it will be significantly less than indicated by public opinion surveys.

NHTSA will continue to inform and educate the public to give consumers the proper perspective on air bags; i.e., that with the exception of child passengers and a limited number of drivers, disabling an air bag greatly increases your chance of death or injury in the event of a crash. NHTSA believes that a combination of this safety campaign and the time that passes since the height of negative media coverage will reduce the interest in on-off switches among non-risk group occupants.

Real Near-Term Impacts

This analysis examines the impact of on-off switches for the years 1998 to 2001. After 2001, NHTSA anticipates that advanced air bags will be available, and the need for on-off switches will be reduced. During this time driver air bag penetration is expected to grow from 37.2% of the 1998 on-road fleet to 52.4% of the 2001 fleet. Passenger air bag penetration will grow from 22.5% in the 1998 fleet to 40.7% in the 2001 fleet. The average air bag installation during these 4 years is estimated to be about 45% for the driver's side and 32% for the passenger's side. Projections of each year's estimated impacts were computed by applying air bag installation rates to the estimated number of fatalities prevented and caused by air bags in a fully air bag equipped vehicle fleet. These estimates were obtained from a previous NHTSA analysis that dealt with the issue of depowering air bags (8) and are summarized in Table 1. The category "child passengers" includes ages 0-12 while "adult passengers" includes ages 13 and over. The resulting estimates for the years 1998-2001 are summarized in Tables 2, 3 , 4 and 5. In Table 6, all 4 years are summarized. The analyses summarized in these tables are based on the assumption that occupant behavior will remain unchanged. If public education programs are successful in creating better awareness of occupant safety issues, the potential negative safety impacts of air bags could be substantially reduced.

As previously discussed, on-off switches should only be used in a limited number of situations, most notably for children in the front seat, for drivers who must sit very close to the steering wheel, and for persons with certain medical conditions. These groups are believed to account for most of the cases of air bag related fatalities estimated in Table 6. If on-off switches are installed and used by all those actually at risk, they could prevent 231 fatalities, 45 drivers and 186 passengers, over the 1998-2001 period. This is an average of 58 fatalities prevented per year over the 4 years.

The survey data previously discussed indicates that there is at least the possibility that persons not at risk from air bag injuries will use them as well. This could have a negative impact on occupant safety because valuable crash protection would be removed. NHTSA will make every effort to inform the public of the dangers of unnecessarily disabling air bags in an effort to minimize any negative safety impact. For every one percent of those in the not-at-risk group who use on-off switches, the number saved by air bags could be reduced by 42 drivers and 9 passengers. This is an average of 13 fatalities per year over the 4 years.

Table 1

Estimated Full Fleet Impacts of Air Bags on Fatalities**

Saved Killed Net Impacts
Drivers 2327 25 2302
Passengers 721 147 574
Adult Passengers 721 7 714
Child Passengers 0* 140 -140
Total 3,048 172 2,876
Source: NHTSA, Final Regulatory Evaluation, Actions to Reduce the Adverse

Effects of Air Bags, Depowering, FMVSS No. 208, Washington D.C., February 1997

*The number of child passengers saved by air bags could not be estimated.

**Based on current design air bags (on the road in 1996). Assumes no change in driver restraint use or seated distance from the air bag. Assumes no change in child restraint use or in the percent of children seated in the front seat.

Table 2

Estimated 1998 Impacts of Air Bags on Fatalities

Saved Killed Net Impacts
Drivers 866 9 857
Passengers 162 34 128
Adult Passengers 162 2 160
Child Passengers 0 32 -32
Total 1,028 43 985
Note: Assumes 37.2% of fleet equipped with driver air bags and 22.5% of fleet equipped with passenger air bags.

Based on current design air bags (on the road in 1996). Assumes no change in driver restraint use or seated distance from the air bag. Assumes no change in child restraint use or in the percent of children seated in the front seat.

Table 3

Estimated 1999 Impacts of Air Bags on Fatalities

Saved Killed Net Impacts
Drivers 987 11 976
Passengers 207 42 165
Adult Passengers 207 2 205
Child Passengers 0 40 -40
Total 1,194 53 1,141
Note: Assumes 42.4% of fleet equipped with driver air bags and 28.7% of fleet equipped with passenger air bags.

Based on current design air bags (on the road in 1996). Assumes no change in driver restraint use or seated distance from the air bag. Assumes no change in child restraint use or in the percent of children seated in the front seat.

Table 4

Estimated 2000 Impacts of Air Bags on Fatalities

Saved Killed Net Impacts
Drivers 1,101 12 1,089
Passengers 250 51 199
Adult Passengers 250 2 248
Child Passengers 0 49 -49
Total 1,351 63 1,288
Note: Assumes 47.3% of fleet equipped with driver air bags and 34.7% of fleet equipped with passenger air bags.

Based on current design air bags (on the road in 1996). Assumes no change in driver restraint use or seated distance from the air bag. Assumes no change in child restraint use or in the percent of children seated in the front seat.

Table 5

Estimated 2001 Impacts of Air Bags on Fatalities

Saved Killed Net Impacts
Drivers 1,219 13 1,206
Passengers 293 60 233
Adult Passengers 293 3 290
Child Passengers 0 57 -57
Total 1,512 73 1,439
Note: Assumes 52.4% of fleet equipped with driver air bags and 40.7% of fleet equipped with passenger air bags.

Based on current design air bags (on the road in 1996). Assumes no change in driver restraint use or seated distance from the air bag. Assumes no change in child restraint use or in the percent of children seated in the front seat.

Table 6

Estimated 1998-2001 Impacts of Air Bags on Fatalities

Saved Killed Net Impacts
Drivers 4,172 45 4,127
Passengers 913 186 727
Adult Passengers 913 9 904
Child Passengers 0 177 -177
Total 5,085 231 4,854
Note: Total number over the 4 year period, assumes an average of 44.8% of fleet equipped with driver air bags and 31.7% of fleet equipped with passenger air bags.

Based on current design air bags (on the road in 1996). Assumes no change in driver restraint use or seated distance from the air bag. Assumes no change in child restraint use or in the percent of children seated in the front seat.

Safety impacts will continue to occur over the remaining life of these pre-2002 model year fleets, but at a declining rate as more vehicles are retired from the fleet without being replaced by on-off switch equipped vehicles. It is apparent from this analysis that minimizing the number of not-at-risk occupants that purchase on-off switches is critical to the goal of improving occupant safety through the use of on-off switches.

Ratio of Fatality Risk

Although air bags can cause injuries and fatalities under certain circumstances, these events are extremely rare compared to those where they provide protection against injury. With the exception of children riding in the front seats, it is difficult to predict which cases will actually benefit from an on-off switch.

For drivers, the bottom line is proximity to the steering wheel hub. Close proximity may be caused by very short stature, by certain rare medical conditions, or in some instances, simply by habit. However, proximity could also be caused by momentary actions such as reaching for a map on the floor, or by temporary conditions such as driving with the seat far forward to accommodate passengers or cargo in the rear seat. Drivers who are not in an at-risk group who decide to use on-off switches will be taking a substantial safety risk. This can be illustrated by calculating the fatality ratio, which is the relative odds of being killed by an air bag compared to being saved. These odds are derived as follows:

x = k/(s + k)
Where:x=chance of being killed rather than saved by air bag (fatality ratio)
k=number of persons killed by air bags
s=number of persons saved by air bags

Data from Table 6 can be used to calculate this rate for each occupant category.

For drivers:x = 45/(4172 + 45)
x = .0106

This means, for example, that in a crash with an air bag deployment, there is a 99 percent chance of a driver being saved by the air bag and only a 1.06 percent chance of being killed by the air bag, in cases where the air bag makes a difference in the fatality outcome of the driver.

For all passengers:x = 186/ (913 + 186)
x = .169
 
For adult passengers:x = 9/(913 + 9)
x = .01
 
For child passengers:x = 177/(0 + 177)
x = 1.0

The ratios point out the vulnerability of child passengers to the air bag, probably due both to children more easily getting into a dangerous area near the air bag and their higher vulnerability to neck injury.

Considering driver fatalities, ninety-nine percent of the time when an air bag goes off, it will save, rather than kill, the driver. The implication is that, unless drivers habitually sit very close to the steering wheel, they should not even consider using an on-off switch.

The low fatality ratio for drivers (i.e., one percent) is consistent with other evidence and crash data as well. NHTSA measured the normal driving distance from the center of the steering wheel to the center of the chest of a small number (21) of short persons to determine their proximity to the air bag. Heights ranged from 4'9" to 5'5". Of the 21 cases, only one measured under 10" and another person of the same stature had a chest to steering wheel measurement of 13". Moreover, in several cases, shorter persons had higher measurements with the shortest (4'9") having an 11" measurement. From this it was concluded that some people 4'8" or less may fall into the at-risk category due to their proximity to the air bag. NHTSA then examined CDS files for the years 1993-1995 and found that roughly one quarter of one percent of all drivers were 4'8" or less. In addition, an unknown number of drivers sit close to the steering wheel out of habit or for comfort, and an unknown number of persons will want switches for medical reasons. NHTSA cannot quantify these groups, but they are not expected to be large. The 1 percent fatality ratio thus seems reasonably consistent with the 0.25 percent who fall into a height category that may require them to sit within 10" of the steering wheel. The fatality ratio for adult passengers is also about 1 percent.

It should be noted that height is, at best, a poor proxy for proximity to the steering wheel. The driver's proximity is also affected by the interior design of the vehicles, the position of the steering wheel, the position of the driver's seat, the angle of the driver's seat back, the relative distribution of individual's height (that is, the legs vs. the torso), arm length, and driving habits. IIHS conducted a survey (see Docket No. 74-14-N107-685) during the spring of 1997 in which it found that 5 percent of female occupants (the equivalent of about 2.5 percent of the overall occupant population) sit closer than 10 inches to the steering wheel. In another study, 13 drivers 4 foot-8 inches to 5 foot-2 inches tall, were asked to sit normally in a driving position. Those drivers who sat closer than 10 inches from the steering wheel were encouraged to adjust their seating positions. When a comfortable position was reached, each drove around a test track to assure that the vehicle could be operated safely in this position. Three of the 13 drivers failed to attain a 10 inch separation. However, none of these drivers were sitting closer than 9 inches from the steering wheel. Ultimately individuals should sit as far away from the steering wheel as possible and still comfortably control their vehicle, and then measure the distance from the center of the air bag to the center of their breastbone to gauge their own level of risk. The agency is advising drivers to sit a minimum of 10 inches or almost 10 inches away. The vast majority of the public should be able to achieve this distance.

Although a ratio of fatality risk can be calculated for child passengers, this ratio is less meaningful because NHTSA is not aware of cases where children were saved by air bags. Crash data on children 12 and under indicates that, if unrestrained, the air bag can cause fatal injury when a child is thrown against the air bag during pre-crash braking or during the actual crash itself. Properly restrained children, with the exception of infants in rear-facing child restraints, are not at significant risk from air bag deployment; however, there are no clear benefits for these children from the air bag. Because of this, the calculated fatality ratio is 100%. The calculated ratio of 100% correctly conveys that consideration should be given to disconnecting air bags when children have to ride in the front seat.

In a letter to NHTSA Administrator, Dr. Martinez dated June 3, 1997, Multinational Business Services (MBS) provided their analysis of the net impacts of allowing on-off switches. Their analysis concludes that the proposed disconnect policy would increase automobile fatalities by 406 deaths annually (295 drivers and 111 passengers) in the year 2000.

NHTSA does not agree with this assessment for three basic reasons:

1) In making their calculation, MBS used NHTSA data that represent a full fleet air bag installation rate. They did not adjust their calculations for the fact that in the year 2000, only 47% of the passenger vehicle fleet will have driver air bags, and only 35% will have passenger air bags. On-off switches may not be necessary after advance air bags are introduced. The scenario examined by MBS will, therefore, never occur.

2) MBS assumes that 12.96% of all air bag vehicles will have cut off switches on the drivers side and that 18.88 % will have them installed on the passenger side. They base these assumptions on the January 1997 IIHS survey. The estimates represent those respondents that wanted the air bag disconnected. As previously discussed, NHTSA does not feel that the results of the January survey are indicative of the portion of drivers that will actually disconnect their air bags for several reasons, including the high level of media coverage at that time, the issue of cost, and the potential impact of public education programs to dissuade those outside an identifiable risk group from disconnecting their air bags.

3) Manufacturers have already made changes to their air bags to make them less aggressive. This is born out in the crash data as well as by laboratory testing that the agency has done.

Nonfatal Injuries

In addition to preventing fatalities, air bags prevent many moderate to critical (MAIS 2-5) injuries. These injuries are typically head/face injuries which would have significant consequences. At the same time, air bags also cause some injuries due to the force of the bag itself. Most air bag-caused injuries involve the head/face or arms. The number of MAIS 2-5 injuries saved by an air bag was estimated based on data in the 1993-1995 CDS files. These data are summarized in the tabular portions of Tables 7 and 8. Note that no savings estimates are made for child passengers because there are currently no air bag injury effectiveness estimates available for children.

The data in these tables represent the injuries that occurred during the 1993-1995 time frame. To estimate the potential savings that could occur from air bags, these numbers must be adjusted to remove the impact of belt use and determine the underlying base rate of MAIS 2-5 injuries in the vehicle fleet. This is done using the following formula:

I= n/1 - u e
Where:I=MAIS 2-5 Injuries at zero safety belt use
n=annual average number of injuries during 1993-1995
u=safety belt usage rate
e=safety belt effectiveness against injuries

Impacts will be calculated for drivers and adult passengers. For drivers, Table 7 indicates that n is 190,908 injuries. Safety belt usage rates during this time period (u) averaged about 68 percent based on a compilation of state surveys. Effectiveness of belts against MAIS 2-5 injuries in passenger cars is 50 percent, and in LTV's it is 65 percent. The weighted average effectiveness for all vehicle types (e) is 53.3 percent. The formula thus becomes:

I = 190,908/(1 - .68 x .533)
I = 299,346

Currently belts are saving I * u * e or 108,464 injuries. To calculate potential air bag benefits, the following formula will be used:

eb=1 - (I + (b-a))/I
Where:eb=average effectiveness of air bags for both belted and unbelted occupants
I=MAIS 2-5 injuries at zero safety belt use
b=number of persons who would be injured by air bags in a fully equipped fleet
a=numbers of persons who would be saved by air bags in a fully equipped fleet
Solving for a, the formula reduces to :
a=eb I + b

To estimate the injury potential for air bags (b), data from 1993-1995 CDS files was examined for cases in which the injury was caused by contact with air bags, air bag covers, or gas released by air bags. These data are summarized in Tables 9 and 10 for drivers and passengers. These data represent the average annual number of MAIS 2-5 injuries caused by air bags during the 1993-1995 period. During this period, NHTSA estimates that an average of 13.74 percent of all on-road passenger vehicles had driver side air bags, and an average of 4.54 percent had passenger air bags. In order to estimate the potential injuries that could occur in a fully air bag equipped vehicle fleet, the 1993-1995 estimates must be adjusted to reflect the air bag penetration during that time. This is done as follows:

Ia=n/i
Where:Ia=projected MAIS 2-5 injuries in a fleet fully equipped with air bags
n=number of injuries in the 1993-1995 fleet
i=portion of vehicles with air bags installed in the vehicle fleet

Thus, for drivers, from Table 9 an average of 3,204 air-bag induced injuries in the 1993-1995 fleet implies 23,315 air-bag induced injuries in a full vehicle fleet (3,204 /.1374 = 23,315). Similar calculations for passengers indicate 8,420 adult passengers and 485 child passengers may receive MAIS 2-5 injuries from current design air bags in a full vehicle fleet.

Safety belt use rates (u) are estimated to be 68% based on state surveys. In passenger cars, air bags and belts combined are estimated to be 55 percent effective against MAIS 2-5 injuries. In LTVs, the effectiveness of these combined systems is 70 percent. The weighted average effectiveness (ec) for both vehicle types is 58.3 percent.

Air bags alone are estimated to be 18 percent(9) effective (ea) against MAIS 2-5 injuries for both cars and LTV's.

eb is calculated as follows:
eb = (ec-e)u+ea(1-u)
eb = (58.3-53.3) x.68+.18(1-.68)
eb = .0916

For drivers, the base target population of MAIS 2-5 injuries (I) was previously calculated to be 299,346. The calculation of injuries saved by air bags thus becomes.

a = (.0916 x 299,346) + 23,315
a = 50,735 drivers saved from injury by air bags

These calculations are shown in the lower part of Table 7. Similar calculations are made for adult passengers in Table 8. From these data, an estimated 50,735 adult drivers and 15,751 adult passengers would be saved from MAIS 2-5 injuries by air bags if they were installed in the entire vehicle fleet.

The projected savings from Tables 7 and 8, as well as the projected full fleet injuries caused by air bags based on Tables 9 and 10, were used to develop a series of estimates similar to those previously developed for fatalities. These estimates are summarized in Tables 11-16.

Air bags prevent more injuries for adults than they cause, but can potentially cause nonfatal injuries to any front seat vehicle occupant. Most of these injuries are minor, especially compared to injuries that would have occurred in the absence of air bags. The potential for injury is not known to be different for members of any particular adult risk group. Similarly, the effectiveness of air bags in preventing injuries is not known to be different for different risk groups. It will, therefore, be assumed that the relative risk of injury to those who use on-off switches is the same as the general population. Under this assumption, if on-off switches are installed and used by one percent of drivers, the potential benefits of air bags would be reduced by about 492 MAIS 2-5 injuries over the 1998-2001 period. This is an average of 123 injuries annually over the 4 years. For adult passengers, for every one percent who utilize on-off switches, the potential benefits of air bags could be reduced by 93 MAIS 2-5 injuries could occur, an average of 23 injuries annually.

For children, due to the lack of data on injuries prevented by air bags, the net impact of on-off switches on nonfatal injuries is uncertain. However, the agency believes that on-off switches would provide a net benefit to children.

NHTSA has considered the impacts of requiring Department of Transportation (DOT) approval for installation of on-off switches. Because there are so many variables, especially the number of people who will request on-off switches, it is impossible to precisely quantify the effects of this approach. On balance, the agency believes that the required approval process will enhance overall safety. Currently, 68 million driver air bags and 39 million passenger air bags are causing approximately 44 deaths annually, or less than one fatality per week. There is a possibility that someone could be killed by an air bag during the approval process. However, the odds that one of these people might die within the time it takes to receive an authorization letter from DOT is extremely small. Moreover, NHTSA believes that the approval process will serve to better ensure that the public carefully considers the risk trade-offs that occur when air bags are disconnected, and better enable people to determine whether they are actually at risk of an air bag injury. This should serve to minimize the participation of occupants not at risk, which is a much larger number than those that are at risk, and reduce unnecessary deaths resulting from improper use of an on-off switch.

Conclusions

It is clear from this analysis that the key to maximizing the benefits of on-off switches is to minimize the level of use of on-off switches by those not at risk of injury. Passenger side on-off switches, when used properly for children 12 and under, have significant positive safety potential in preventing fatalities. Passenger side on-off switches, when used by those over 12 years of age, could result in a reduction of potential air bag benefits. Driver position on-off switches could result in a reduction of potential air bag benefits unless on-off switch use is confined to those actually at risk.

Given the large numbers of lives currently being saved by air bags and the very small chance of an air-bag related fatality, NHTSA recognizes the possibility that a rule permitting on-off switches could result in net safety disbenefits. However, the agency also believes it must consider both the short-run and long-run implications of this rulemaking on safety. Ultimately, the continued availability of any safety device as standard equipment, whether provided voluntarily by manufacturers or pursuant to a regulation, is dependent on consumer acceptability. The agency believes that current-design air bags which fatally injure occupants, particularly children in low speed crashes, raise significant concerns about air bags, despite their overall net safety benefits. Accordingly, to help ensure that air bags remain acceptable to consumers and ultimately achieve their full potential in the future (as advanced air bags are developed and implemented), the agency believes it is reasonable to permit persons who are at risk the opportunity to obtain and use an on-off switch. However, the agency emphasizes that it will seek through its public education campaign, through requiring purchasers of on-off switches to certify that they are in a identified risk group and have read the safety brochure, and other means to reduce the current misperception of risk and to urge that only those persons actually at risk obtain and use an on-off switch.

Table 7

1993-1995 Average CDS*, Drivers w/ AIS 2-5 Injury

Pickups
Passenger

Cars

Other LTVs
Non-Pickups Total
Total Drivers 21521 148277 21110 169387 190908
PC % Total = 0.781
LTV % Total = 0.219
1993-1995 Usage Rate = 67.98%
PC belt eff = 0.5
LTV belt eff = 0.65
Wtd belt eff = 53.29%
Potential MAIS 2-5 = 299346
Belt Savings @68% = 108464
Current Usage Rate = 0.68
PC Bag & belt eff = 0.55
LTV Bag & belt eff = 0.7
Wtd Bag & belt eff = 58.29%
Bag eff, both PC &LTV 0.18
Wtd Bag bltd unbltd eff = .0916
Injuries caused by air bags = 23315
Bag MAIS 2-5 benefits = 50735 drivers

* CDS = Crashworthiness Data System

Table 8

1993-1995 Average CDS, Front Seat Occupants Excluding

Drivers w/ AIS 2-5 Injury

Pickups Passenger Cars Other LTVs Non-Pickups Total
Infants 0 261 0 261 261
Ages 1-12 499 2738 225 2963 3462
Total Children 499 2999 225 3224 3723
Ages 13 & Over 8565 36872 7191 44063 52628
Ages 1 & Over 9064 39610 7416 47026 56090
Total 9064 39872 7416 47287 56352
PC % Total = 0.781
LTV % Total = 0.219
1993-1995 Usage Rate = 64.27%
PC belt eff = 0.5
LTV belt eff = 0.65
Wtd belt eff = 53.29%
Potential MAIS 2-5 = 80037
Belt Savings @68% = 29000
Current Usage Rate = 0.68
PC Bag & belt eff = 0.55
LTV Bag & belt eff = 0.7
Wtd Bag & belt eff = 58.29%
Bag eff, both PC &LTV 0.18
Wtd Bag bltd unbltd eff = .0916
Injuries caused by Air Bag = 8420
Bag MAIS 2-5 benefits = 15751 adult passengers

Table 9

1993-1995 Average CDS, Drivers

w/ Air Bag Caused MAIS 2-5 Injury

Pickups Passenger Cars Other LTVs Non-Pickups Total
Infants 0 0 0 0 0
Ages 1-12 0 0 0 0 0
Total Children 0 0 0 0 0
Ages 13 & Over 0 2277 927 3204 3204
Ages 1 & Over 0 2277 927 3204 3204
Total 0 2277 927 3204 3204

Table 10

1993-1995 Average CDS, Front Seat Occupants Excluding Drivers

w/ Air Bag Caused MAIS 2-5 Injury

Pickups Passenger Cars Other LTVs Non-Pickups Total
Infants 0 0 0 0 0
Ages 1-12 0 13 9 22 22
Total Children 0 13 9 22 22
Ages 13 & Over 0 382 0 382 382
Ages 1 & Over 0 395 9 404 404
Total 0 395 9 404 404

Table 11

Estimated Full Fleet Impacts of Air Bags on

Nonfatal Injuries (MAIS 2-5)

Prevented Injured Net Impacts
Drivers 50,735 23,315 27,420
Passengers
Adult Passengers 15,751 8,420 7,331
Child Passengers unknown 485 unknown
Total 66,486 32,220 34,266
Source: NHTSA, Final Regulatory Evaluation, Action to Reduce the Adverse Effects of Air Bags Depowering FMVSS No. 208, Washington D.C., February 1997

Based on current design air bags (on the road in 1996). Assumes no change in driver restraint use or seated distance from the air bag. Assumes no change in child restraint use or in the percent of children seated in the front seat.

Table 12

Estimated 1998 Impacts of Air Bags on

Nonfatal Injuries (MAIS 2-5)

Prevented Injured Net Impacts
Drivers 18,873 8,673 10,200
Passengers
Adult Passengers 3,544 1,895 1,649
Child Passengers unknown 109 unknown
Total 22,417 10,677 11,741
Note: Assumes 37.2% of fleet equipped with driver air bags and 22.5% of fleet equipped with passenger air bags.

Based on current design air bags (on the road in 1996). Assumes no change in driver restraint use or seated distance from the air bag. Assumes no change in child restraint use or in the percent of children seated in the front seat.

Table 13

Estimated 1999 Impacts of Air Bags on

Nonfatal Injuries (MAIS 2-5)

Prevented Injured Net Impacts
Drivers 21,512 9,886 11,626
Passengers
Adult Passengers 4,521 2,417 2,104
Child Passengers unknown 139 unknown
Total 26,032 12,441 13,591
Note: Assumes 42.4% of fleet equipped with driver air bags and 28.7% of fleet equipped with passenger air bags.

Based on current design air bags (on the road in 1996). Assumes no change in driver restraint use or seated distance from the air bag. Assumes no change in child restraint use or in the percent of children seated in the front seat.

Table 14

Estimated 2000 Impacts of Air Bags on

Nonfatal Injuries (MAIS 2-5)

Prevented Injured Net Impacts
Drivers 23,998 11,028 12,970
Passengers
Adult Passengers 5,466 2,922 2,544
Child Passengers unknown 168 unknown
Total 29,463 14,118 15,345
Note: Assumes 47.3% of fleet equipped with driver air bags and 34.7% of fleet equipped with passenger air bags.

Based on current design air bags (on the road in 1996). Assumes no change in driver restraint use or seated distance from the air bag. Assumes no change in child restraint use or in the percent of children seated in the front seat.

Table 15

Estimated 2001 Impacts of Air Bags on

Nonfatal Injuries (MAIS 2-5)

Prevented Injured Net Impacts
Drivers 26,585 12,217 14,368
Passengers
Adult Passengers 6,411 3,427 2,984
Child Passengers unknown 197 unknown
Total 32,996 15,841 17,154
Note: Assumes 52.4% of fleet equipped with driver air bags and 40.7% of fleet equipped with passenger air bags.

Based on current design air bags (on the road in 1996). Assumes no change in driver restraint use or seated distance from the air bag. Assumes no change in child restraint use or in the percent of children seated in the front seat.

Table 16

Estimated 1998 to 2001 Impacts of Air Bags on

Nonfatal Injuries (MAIS 2-5)

Prevented Injured Net Impacts
Drivers 90,968 41,804 49,164
Passengers
Adult Passengers 19,941 10,660 9,281
Child Passengers unknown 614 unknown
Total 110,909 53,078 57,831
Note: Assumes 44.8% of fleet equipped with driver air bags and 31.7% of fleet equipped with passenger air bags.

Based on current design air bags (on the road in 1996). Assumes no change in driver restraint use or seated distance from the air bag. Assumes no change in child restraint use or in the percent of children seated in the front seat.

COSTS

Administrative Costs and On-off Switch Installation Costs

There are fixed costs associated with designing and developing a database to store the information and for use by NHTSA personnel and for hardware costs. These one-time costs are estimated to be about $85,000. In addition, costs to maintain the data base and other fixed costs are estimated to be about $135,000 per year.

The process of acquiring an air bag on-off switch will potentially involve costs for consumers, NHTSA, motor vehicle dealers, and any other entities involved in the distribution of information brochures and request forms. Following is a brief summary of this process:

ON-OFF SWITCH AUTHORIZATION PROCESS

Variable costs for each of these steps will be estimated separately in the following sections:

NHTSA Costs for Supplying and Mailing Information Brochures and Request Forms:

In conjunction with the Final Rule, NHTSA would mail a supply of information brochures and request forms to the 22,750 new vehicle dealers and to each of the 4,100 State Department of Motor Vehicle offices, State Highway Safety Offices, several national organizations, and have a stock available to be mailed out by the NHTSA Hotline and regional offices. It is anticipated that many more people will read the information brochures than will fill out the request form and obtain on-off switches. It is also anticipated that availability of the information brochure and request form on the Internet will reduce the need for mailings. The agency has no directly relevant experience upon which to base an estimate. However, for compliance with the Paperwork Reduction Act, NHTSA has estimated that the number of persons who read the brochure will be at least one million over the three year period following the issuance of the final rule. Thus, the annual average will be about 330,000 people. The cost of information brochures is estimated to be $0.25 each. The cost of a request forms is estimated to be $0.005 each.

The estimated average annual cost based on this three year period would be:

Information brochures: 330,000 x $0.25 = $82,500

Request forms = 330,000 x $0.005 = $1,650

Mailing costs to the dealer or DMV office would be about $2 for each distributor for a cost of $53,700 ((22,750 + 4,100) x 2).

Total costs for producing information brochures and request forms and for mailing them to other distributors is estimated to be $137,850.

Consumer Costs to Obtain Information Brochure and Request Form:

Consumers can obtain the brochure and form by sending a written request, by placing a phone call to NHTSA's Hotline, or by driving to a local distribution point, such as a motor vehicle dealer or DMV. The least expensive way would be through NHTSA's Hotline, which is a toll-free number and thus costs consumers nothing. However, not all consumers will be aware of this, so some may write to NHTSA, visit a nearby dealer, or DMV. Sending a letter would cost no more than $0.35 per letter (assuming $0.32 postage plus $0.03 for paper and envelope). If half of the persons requesting the brochure and form sent a written request to obtain this information, annual costs would total $57,750 (330,000 requests x 0.5 x $.35). Costs to visit a local source are discussed later under "Consumer Travel Time to Dealership Cost". However, if it is assumed that consumers act rationally, they would not choose to drive if it costs them substantially more than it would to send a mail request.

NHTSA Mailing Costs for Sending Brochures and Request Forms to Consumers:

An unknown number of consumers will request forms directly from NHTSA, rather than from a dealer, or the DMV. The mailing cost to NHTSA of sending these items is $0.55 for each response, based on current postal rates. In addition, the envelope costs about $0.05. Assuming 50 percent of the consumers request the information through the HOTLINE or by writing to NHTSA, the costs for mailing the information brochures and request forms would annually be: 330,000 x .50 x $0.60 = $99,000.

Consumer Costs to Read Brochure and Fill Out Request Form:

Individual vehicle owners will be required to read an information brochure prepared by NHTSA about the risk tradeoffs that result from turning off air bags. The owners must then fill out a request form attesting that they have read the information brochure and providing specific information about the vehicle, including which air bag (driver or passenger or both) they intend to install an on-off switch for. The owners must also certify that they are, or a user of their vehicle is, a member of one of the risk groups listed on the form. Finally, the owners must affirm that the information provided is truthful to the best of their knowledge and belief. NHTSA estimates it will take each owner 25 minutes to read and understand the information brochure, and 5 minutes to fill out the request form. For compliance with the Paperwork Reduction Act, NHTSA estimates that at least 100,000 authorization letters will be submitted to dealers or repair businesses in the first year after the issuance of this final rule, and that the annual average for the three year period will be approximately 80,000. For the estimated 80,000 annual requests that are made for on-off switches, consumers would expend a total of 40,000 manhours.

To value the time spent in these tasks, DOT guidance regarding the value of travel time will be used as a proxy. DOT has established departmental guidance for valuing travel time based on hourly compensation and the relative value of personal time. The Department recommends using a value of $8.90 in 1995 economics. This represents a weighted average of personal and business trips. It values business trips at 100 percent of hourly earnings rates (including both wages and fringe benefits) and personal time at 50 percent of hourly earnings rates. Adjusted to 1996 economics, the weighted value is $9.20 based on the change in Average Hourly Earnings as reported by the Bureau of Labor Statistics. ($11.81/$11.43).

Although time spent reading a brochure and filling out a form is not the same thing as travel time, NHTSA believes that the same basic factors, i.e., wage compensation and the relative value that people put on their personal time, are relevant. Also, NHTSA has no data to estimate what portion of the population would accomplish these tasks during normal time off, such as weekends, or would take time off from their jobs. In the later case, NHTSA believes that the full value of wage compensation would be an appropriate value. Therefore, some mix of personal time valuations (@ 50% of the wage) and business valuations (@ 100% of the wage) is involved. Although NHTSA has no information to determine the relative incidence of these trips, it is believed that the value specified in the Departmental guidance, which is weighted by the frequency of these types of trips, is a reasonable proxy for the value of time that will be spent in these tasks. The value of manhours spent by vehicle owners obtaining authorization for an on-off switch is thus estimated to be $368,000 (40,000 manhours x $9.20).

Consumer Costs to Return Request Form to NHTSA :

Under the final rule, request forms would have to be mailed to NHTSA for approval. Mailing costs would be $0.32 each at current postal rates. The mailing envelope is estimated to cost no more than 3 cents. Total costs for mailing the request form and would thus be $28,000 for 80,000 forms (80,000 x $0.35)

NHTSA Costs to Review Request Form.

When owners submit request forms to NHTSA, staff will be required to open envelopes, verify that the forms are correctly filled out and that responses meet all legal requirements. It is estimated that this will take about 1 minute per form. Based on estimated contractor costs, the cost per hour for the verification process would be $26. The 80,000 annual request forms represent 1,333 hours of verification time (80,000 forms x 1 minute / 60 minutes per hour). The total cost to NHTSA for the verification process would thus be $34,658 (1,333 hours x $26).

NHTSA Costs for Recording and Storing Information:

The time needed to scan the forms into a data base with the name, VIN, address, reason for purchasing an on-off switch, and seating position(s) affected; verify and correct the scanned information is estimated to be about 2 minutes per form or $69,333 for 80,000 forms ($26 per hour/60 minutes x 2 minutes x 80,000).

NHTSA Costs to Send Authorization Letter to Vehicle Owners:

After verifying that all conditions have been met on the request form, NHTSA will send a separate authorization letter to the vehicle owner allowing him/her to obtain an on-off switch. Based on bulk rate postage costs, the postage and envelope required will cost $.30 per letter ($0.28 postage and $0.02 cents for the paper and envelope) or a total mailing cost of $24,000 for the 80,000 forms

Consumer Cost to Travel to Dealership:

Vehicle owners will spend an unknown amount of time driving to and from the dealership that installs the on-off switch. They may make several trips, one to obtain a form, the other to get the work done. They might drop off the vehicle and return on yet another trip to pick it up. To confuse matters even more, consumers might stop at dealerships to have the switch installed while in the area doing other tasks such as shopping. NHTSA has no data to estimate the net impact on consumers' time that will result from this procedure. As noted previously, it is estimated that a reasonable proxy for the value of this lost time is $9.20 per hour. For the 80,000 requests, total costs would thus be $736,000 for each hour spent in an average transaction.

Installation Costs for On-Off Switches:

The agency had estimated the consumer price impact for a passenger-side air bag on-off switch as original equipment to be $4.86 (1993 dollars) in its March 1995 "Final Regulatory Evaluation, FMVSS No. 208, Air Bag Cutoff Device." This per-seat cost is approximately $5.20 (1996 dollars), or probably less than $10.40 per vehicle for both air bag positions, the driver and right front passenger seat, if NHTSA allowed driver-side on-off switches as original equipment.

General Motors Corporation provided comments to Docket 74-14; Notice 100, Occupant Crash Protection, in which they disputed the Agency's current cost estimate ("a little more than five dollars") for a manual on-off switch for the right front passenger side. General Motors responded that "Manual switches are ... about $10.00 installed, considering wiring, I/P tooling, and assembly plant costs." This refers to installation in new vehicles, not aftermarket costs.

Typically, aftermarket cost for an original equipment product is 2.5 times an estimated consumer cost for that original equipment product. Thus, based on NHTSA's consumer cost estimates, it is estimated that the aftermarket on-off switch consumer cost would be $13.00 (1996 dollars) for the right front passenger seat and less than $26.00 for both driver and right front passenger. The time it takes to install an on-off switch is dependent upon whether the instrument panel must be removed to install the on-off switch. NHTSA previously estimated in the NPRM that it would take between 30 minutes and an hour at a national average cost of up to $50 per hour. (The AAMA Motor Vehicle Facts and Figures 1996, page 74, indicates that the National Automobile Dealers Association estimate that in 1995 the average customer mechanical labor rate is $48 per hour ($50 per hour (1996 dollars) is used in the calculations)). Thus, NHTSA estimates that the cost of providing an on-off switch for a single position is $38 to $63, and the consumer cost of providing an on-off switch for both driver and passenger side is $51 to $76.

In their comment to Docket 74-14; Notice 107, Ford Motor company provided an initial cost and installation analysis of three methods of turning an air bag off that they were investigating. The on-off switch assumed by Ford applies to either seating position or both seating positions. The shorting bar removal strategy requires no new parts, thus, the total cost was labor and implies a labor cost of $64.00 per hour. Assuming the same labor cost is used for the on-off switch estimate, the aftermarket cost of the parts for the on-off switch would be $28.00 to $31.00. ($95 - 1 x $64 = $31 and $124 - 1.5 x $64 = $28). Thus, while NHTSA and Ford have very close estimates for the cost of an on-off switch, Ford estimated a higher cost per hour and a longer time to install the on-off switch, resulting in an estimated cost for driver and right front passenger on-off switch assembly of $95 to $124, compared to NHTSA's estimate of $51 to $76. Obviously, the cost consumers will pay is dependent upon what the manufacturer charges for the on-off switch and what the dealership or repair garage charges for installation. The total cost for 80,000 annual installations would thus be between $4.1 million (80,000 installations x $51) and $9.9 million (80,000 installations x $124).

Dealer Costs to Send Confirmation of Modification to NHTSA:

Dealers will incur mailing and clerical costs to send confirmation of the modifications that they perform to NHTSA. If dealers mail only one form per envelope, mailing costs would total $0.35 per form ($0.32 postage and $0.03 per envelope) or $28,000 for 80,000 forms. Clerical costs would result from the time needed to address the envelopes and record the confirmation. It is estimated that this process will not exceed 5 minutes per form. Assuming costs similar to those currently experienced by NHTSA, ($26 per hour), total costs for 80,000 forms would be $173,333 (80,000 forms x 5 minutes / 60 minutes per hour x $26). Total dealer costs to send confirmation of modifications would therefore be $201,333.

NHTSA Costs to Record Confirmation:

NHTSA will scan the confirmation. This is estimated to take about 70 seconds per form or $40,444 (80,000 forms x 70 second/60 minutes per hour/60 seconds per minute x $26 per hour).

Cost Summary:

There are fixed costs associated with designing and developing a database to store the information and for use by NHTSA personnel and for hardware costs. These one-time costs are estimated to be about $85,000. In addition, costs to maintain the data base and other fixed costs are estimated to be about $135,000 per year.

Following is a summary of the variable costs that would occur to each of the parties involved in the authorization process for the average of 80,000 requests, the minimum annual average number of requests that are expected to be filed:

NHTSAConsumersDealers
NHTSA supplies forms$137,850
Consumers obtain forms$57,750
NHTSA sends forms to Consumers$99,000
Consumers fill out forms$368,000
Consumers return forms$28,000
NHTSA verifies forms$34,700
NHTSA records requests$69,300
NHTSA responds to requests$24,000
Consumer travel time$736,000
Installation costs$4.1 - $9.9 mil.
Dealer confirmation$201,300
NHTSA records confirmation$40,400
Total$405,250$5.3 - $11.1 mil. $201,300

Total annual variable costs associated with acquiring on-off switches for 80,000 vehicles would therefore be between $5.9 million and $11.7 million.

The agency is planning to analyze the data base of on-off switch approvals to determine whether particular sections of the country are requesting on-off switches at much greater rates than other sections of the country, and to determine the reasons for requesting on-off switches in order to focus public education programs where needed. Cost estimates for this activity have not been established.

SMALL BUSINESS IMPACTS

The Regulatory Flexibility Act of 1980 requires agencies to evaluate the potential effects of their proposed and final rules on small businesses, small organizations, and small governmental jurisdictions.

This final rule allows owners of vehicles to get on-off switches installed and allows motor vehicle dealers and repair business to install them. It does not require either group to do so. It is anticipated that the majority of on-off switch installations will occur at a new vehicle dealer, unless owners can get the job done for a lower cost using an aftermarket kit and a repair business to install it.

Small entities are determined by whether they qualify for a Small Business Administration Loan. The small business criteria is stated in 13 CFR 121.601. Based on this information, the dollar value of sales is the determining factor for defining a small business in this area. These are for the Standard Industrial Classification (SIC) code :

SIC 5511, Motor Vehicle Dealers (New and Used) -- $17 million in sales

SIC 5521, Motor Vehicle Dealers (Used Only) -- $11.5 million in sales

SIC 5541, Gasoline Service Stations -- $4.5 million in sales.

Based on the "Motor Vehicle Facts & Figures, 1996", by the American Automobile Manufacturer's Association, pg. 74, there were 22,750 new motor vehicle dealers in the United States in 1995. The average annual sales for these establishments were slightly over $20 million. Since the definition of a small business is a business with annual sales under $17 million, a large proportion (perhaps 40 to 50 percent) of the new vehicle dealers would probably be classified as small businesses. In addition, the agency believes there are about 30,000 used vehicle dealers and several hundred thousand motor vehicle repair businesses. In essence, there are a substantial number of small businesses that are dealers or repair businesses. For every 100,000 vehicle owners who voluntarily decide to have an on-off switch installed at a new vehicle dealer, the average new vehicle dealer would conduct 4.4 business transactions (100,000/22,750). Dealer and repair business participation is voluntary.

 

 



 

 

1. Some nonfatal injuries are unrelated to the factors (sitting distance from air bag and medical conditions) which define the driver risk groups. For example, since all drivers must hold the steering wheel, they are all subject to arm injuries without regard to those factors.

2. This potential increase applies to all drivers, not just those in a risk group.

3. In expressing their views on these issues, even those commenters who discussed on-off switches as a means under the exemption for turning off air bags generally discussed the eligibility and procedural issues in terms of deactivation alone. NHTSA understands that the commenters generally intended those views regarding eligibility and procedure to apply equally to deactivation and on-off switches.

4. As explained below, full deactivation will continue to be available in limited circumstances, mainly when an on-off switch is not available, through the agency's exercise of its prosecutorial discretion.

5. Contrary to some media reports, the back seat has always been much safer. Sitting in the back seat significantly reduces the likelihood of fatal injury for children, even in vehicles without air bags. Further, sitting in the back seat helps restrained children just as much as it helps unrestrained children. To quantify the benefits of sitting in the back seat, NHTSA analyzed data from vehicle crashes in 1988-1994. Very few of the vehicles in those crashes had passenger air bags. The agency concluded that placing children in back reduced the risk of death in a crash by 27 percent. This conclusion applies to restrained as well as unrestrained children. The size of this reduction can be appreciated from considering the following example. The number of children killed each year while riding in the front seat of a vehicle is over 500. If those 500 children had instead been sitting in the back seat, 135 of those children would still be alive because the back seat is a much safer seating environment for reasons having nothing to do with air bags. A new study by the Insurance Institute for Highway Safety (IIHS) reaches a similar conclusion about the benefits of sitting in the back seat. After examining data from essentially the same time period regarding more than 26,000 children riding in vehicles that were involved in fatal crashes and lacked passenger air bags, IIHS concluded that sitting in the back seat reduced the death rates by more than 27 percent, whether the children were restrained or not. The safest position of all was the center rear seat.

6. NHTSA is recommending 10 inches as the minimum distance that drivers should keep between their chest and their air bags for several reasons. First, the agency believes that drivers who maintain a 10-inch distance will not be at risk of serious air bag injury. Drivers who can maintain that distance will be much safer if they keep their air bags on. The 10-inch distance is a general guideline that includes a clear safety margin. IIHS recommended the same distance in its comments. The 10-inch distance ensures that vehicle occupants start far enough back that, between the time that pre-crash braking begins and time that the air bag begins to inflate, the occupants will not have time to move forward and contact the air bag until it has completed or nearly completed its inflation. The 10 inch-distance was calculated by allowing 2-3 inches for the size of the risk zone around the air bag cover, 5 inches for the distance that occupants may move forward while the air bags are fully inflating, and 2-3 more inches to give a margin of safety. The 5-inch rule of thumb commonly used in air bag design is described in the paper, "How Airbags Work (Design, Deploying Criteria, Costs, Perspectives)" presented by David Breed at the October 19-20, 1992 Canadian Association of Road Safety Professional International Conference on Airbags and Seat Belts.

Second, the agency is focusing attention on that number because it wants drivers to strive to get back 10 inches. NHTSA believes that almost everyone can achieve at least 10 inches and get the extra margin of safety that comes from sitting that far back. See the July 1997 survey submitted by IIHS.

However, some drivers who cannot get back a full 10 inches will still be safer, on balance, if they are protected by their air bag. The nearer that these drivers can come to achieving the 10-inch distance, the lower their risk of being injured by the air bag and the higher their chance of being saved by the air bag. Since air bag performance differs among vehicle models, drivers may wish to consult their vehicle manufacturer for additional advice.

7. Vehicle manufacturers which install on-off switches in new vehicles lacking a rear seat capable of accommodating a rear-facing infant seat must, among other things, must provide a statement of the safety consequences of using the on-off switch to turn off the passenger air bag for persons other than infants in such seats. See S4.5.4 and S4.5.4.4 of Standard No. 208. To comply with that requirement, manufacturers state that the air bag will not inflate in a crash and that the occupant therefore will not have the extra protection of the air bag. To conform S4.5.4.4 to this final rule, NHTSA will soon issue a notice proposing to amend that provision so that it requires listing the same risk groups listed in the information brochure and requires a statement of the safety consequences of using the on-off switch for persons not listed in those groups.

8. NHTSA, Final Regulatory Evaluation, Action to Reduce the Adverse Effects of Air Bags, FMVSS No. 208, Depowering, Washington, D.C. February 1977.

9. "Third Report to Congress Effectiveness of Occupant Protection Systems and Their Use," National Highway Traffic Safety Administration (NHTSA), DOT HS 808 537, December 1996.