DEPARTMENT OF TRANSPORTATION
National Highway Traffic Safety Administration
49 CFR Part 571
[Docket No. NHTSA-02-11707]
Federal Motor Vehicle Safety Standards;
Child Restraint Systems
AGENCY: National Highway Traffic Safety Administration (NHTSA), Department of Transportation.
ACTION: Notice of proposed rulemaking (NPRM).
SUMMARY: This document proposes a number of revisions to the Federal safety standard for child restraint systems, including proposals for incorporating improved test dummies and updated procedures used to test child restraints, new or revised injury criteria to assess the dynamic performance of child restraints, and extension of the standard to apply it to child restraints recommended for use by children up to 65 pounds. This action is intended to make child restraints even more effective in protecting children from the risk of death or serious injury in motor vehicle crashes. This proposal is being issued in response to the Transportation Recall Enhancement, Accountability and Documentation Act of 2000, which directed NHTSA to initiate a rulemaking proceeding for the purpose of improving the safety of child restraints.
DATES: You should submit your comments early enough to ensure that Docket Management receives them not later than [INSERT DATE 60 DAYS AFTER DATE OF PUBLICATION IN THE FEDERAL REGISTER].
ADDRESSES: You may submit your comments in writing to: Docket Management, Room PL-401, 400 Seventh Street, SW., Washington, DC, 20590. Alternatively, you may submit your comments electronically by logging onto the Docket Management System website at http://dms.dot.gov. Click on "Help & Information" or "Help/Info" to view instructions for filing your comments electronically. Regardless of how you submit your comments, you should mention the docket number of this document. You may call Docket Management at 202-366-9324. You may visit the Docket from 10:00 a.m. to 5:00 p.m., Monday through Friday.
FOR FURTHER INFORMATION CONTACT:
For non-legal issues, you may call Mike Huntley of the NHTSA Office of Crashworthiness Standards, at 202-366-0029.
For legal issues, you may call Deirdre Fujita of the NHTSA Office of Chief Counsel, at 202-366-2992.
You may send mail to both of these officials at the National Highway Traffic Safety Administration, 400 Seventh St., S.W., Washington, D.C., 20590.
Table of Contents
I. EXECUTIVE SUMMARY
This document proposes a number of revisions to Federal Motor Vehicle Safety Standard No. 213, "Child Restraint Systems" (49 CFR §571.213). The proposed revisions would incorporate five elements into the standard: (a) an updated bench seat used to dynamically test add-on child restraint systems; (b) a sled pulse that provides a wider test corridor; (c) improved child test dummies; (d) expanded applicability to child restraint systems recommended for use by children weighing up to 65 pounds; and (e) new or revised injury criteria to assess the dynamic performance of child restraints. This proposal follows up on the agency's announcement in its November 2000 Draft Child Restraint Systems Safety Plan (Docket NHTSA-7938) that the agency will be undertaking rulemaking on these and other elements of Standard No. 213 (65 FR 70687; November 27, 2000). The proposal is also issued in response to the mandate in the Transportation Recall Enhancement, Accountability and Documentation Act (the TREAD Act) (November 1, 2000, Pub. L. 106-414, 114 Stat. 1800) to initiate a rulemaking for the purpose of improving the safety of child restraints.
Section 14(a) of the TREAD Act mandates that the agency "initiate a rulemaking for the purpose of improving the safety of child restraints, including minimizing head injuries from side impact collisions." Section 14(b) identifies specific elements that the agency must consider in its rulemaking. The Act gives the agency substantial discretion over the decision whether to issue a final rule on the specific elements. Section 14(c) specifies that if the agency does not incorporate any element described in §14(b) in a final rule, the agency shall explain in a report to Congress the reasons for not incorporating the element in a final rule.
In response to section 14, the agency comprehensively examined possible ways of revising and updating its child restraint standard. Today's proposal is substantially based on a combination of pre- and post-TREAD Act agency activities, including extensive testing of child restraints and dummies by NHTSA's Vehicle Research & Test Center and by the agency in its New Car Assessment Program, and on evaluations of vehicle seat assemblies and pulses. The proposal is also based on data analysis, as well as agency review of existing global research papers and international standards. We have also taken into consideration submissions by the public in response to the agency's Safety Plan and sought an exchange of ideas with child restraint manufacturers as to the research being conducted in response to the TREAD Act, meeting with them in February 2001. There are a number of technical reports in the docket to which this NPRM will refer to from time to time in support of the proposals.
In an advance notice of proposed rulemaking published concurrently with today's document, we are seeking public comments on the agency's work on developing a possible side impact protection standard for child restraint systems and on possible refinements to the approach we have taken thus far. In its review of the child restraint standard, NHTSA placed particular emphasis on improving the ability of child restraints to provide protection in side impact crashes. Although we have conducted extensive testing and analysis over the past year aimed at providing additional side impact protection for children in child restraints, there are many unknowns. We seek comment on the suitability of the test procedures we are considering, on appropriate injury criteria for children in side impacts, on cost beneficial countermeasures, and on other issues. The agency anticipates that comments to the advance notice will help us assess the benefits and costs of a side impact rulemaking, which will help us decide whether to issue a notice of proposed rulemaking in the near future and/or identify the work that needs to be done.
The proposed updates to the seat assembly are based on studies that NHTSA contracted to have done in response to the TREAD Act. This NPRM proposes the following changes: the seat bottom cushion angle would be increased from 8 degrees off horizontal to 15 degrees; the seat back cushion angle would be increased from 15 degrees off the vertical to 22 degrees; the spacing between the anchors of the lap belt would be increased from 222 millimeters (mm) to 392 mm in the center seating position and from 356 mm to 472 mm in the outboard seating positions; and the seat back of the seat assembly would be changed, from a flexible seat back to one that is fixed, to represent a typical rear seat in a passenger car.
The proposed changes to the sled pulse are based on studies conducted in response to the TREAD Act. We propose to widen the test corridor to make it easier for more test facilities to reproduce. The wider corridor extends the pulse from 80 milliseconds (ms) to approximately 90 ms in duration. The expanded corridor would not reduce the stringency of the test, and would also make it easier to conduct compliance tests at speeds closer to 30 mph.
This document proposes two initiatives toward enhancing the use of test dummies in the evaluation of child restraints under Standard No. 213. NHTSA proposes to replace some of the existing dummies with the new 12-month-old Child Restraint Air Bag Interaction (CRABI) dummy, and the state-of-the art Hybrid III 3- and 6-year-old dummies. NHTSA also proposes testing child restraints for older children with a weighted 6-year-old dummy (i.e., a Hybrid III 6-year-old dummy to which weights have been added). The total weight of the dummy would be 62 lb. The weighted dummy would be used to test child restraints that are recommended for children weighing 50 to 65 lb, and is viewed as an interim measure until such time as the Hybrid III 10-year-old dummy becomes available.
The proposal to extend Standard No. 213 to child restraint systems for children who weigh 65 lb or less is based on the proposal to test restraints recommended for children weighing over 50 lb with the weighted 6-year-old dummy. The availability of that dummy makes it possible to extend the standard and evaluate the performance of the added restraints.
The proposal to use the new and scaled injury criteria of Standard No. 208 is based on research that the agency did in the advanced air bag rulemaking, as well as NCAP and sled testing done in response to the TREAD Act. The scaled head injury criterion limits from the Standard No. 208 rulemaking are proposed herein for Standard No. 213, as well as the chest deflection and acceleration limits. The Nij neck criterion would also be added to Standard No. 213, but without the limits on axial force. For Standard No. 208, the agency originally proposed Nij without limits on axial force. However, the Alliance of Automotive Manufacturers persuaded the agency to incorporate more conservative axial force limits for the out-of-position air bag loading environment. 65 FR 30717, 30718; May 12, 2000. Children in child restraints are correctly positioned and not sustaining neck injuries such as those associated with exposure to severe out-of-position air bag loading. Therefore, the agency is proposing that Nij without limits on axial force be added to Standard No. 213.
NHTSA has examined the benefits and costs of these proposed amendments, wishing to adopt only those amendments that contribute to improved safety, and mindful of the principles for regulatory decisionmaking set forth in Executive Order 12866, Regulatory Planning and Review. Its efforts to do so, however, have been limited by several factors. Two factors stand out. One is the limited time allowed by the schedule specified in the TREAD Act for initiating and completing this rulemaking. That has limited the amount and variety of information that the agency could obtain and testing that the agency could conduct to examine the efficacy of possible countermeasures under consideration and the effects of the various proposed amendments on child restraint performance. The other is the lack of specific accident data on children in motor vehicle crashes generally. For example, there is little available data on neck injury in children involved in motor vehicle crashes. Together, these limitations have made it difficult to assess and compare the benefits and costs of this rulemaking.
NHTSA estimates that the proposal to use the new and scaled injury criteria of Standard No. 208 would prevent an estimated 3-5 fatalities and 5 MAIS 2-5 non-fatal injuries for children ages 0-1 annually. In addition, the proposal would save 1 fatality and mitigate 1 MAIS 2-5 injury in the 4- to 6-year-old age group annually. The agency does not believe that updating the seat assembly and revising the crash pulse would affect dummy performance to an extent that benefits would accrue from such changes. Research will be conducted later this year to assess the effects of such changes on dummy performance.
At this time, NHTSA has not identified countermeasures to improve child restraint performance in frontal tests that would allow child restraint manufacturers to meet the proposed neck injury criterion. Consequently, we were unable to estimate the costs of such countermeasures. Comments are requested on possible countermeasures and their costs. The proposal to use new dummies in compliance tests, including testing with a weighted 6-year-old dummy, could result in increased testing costs for manufacturers that want to certify their restraints using the tests that NHTSA will use in compliance testing. NHTSA estimates that use of the new dummies and other changes to the test procedure would add testing costs of $2.72 million. We believe that those changes would not result in redesign of child restraints.
The lack of occupant restraint use by motorists is a significant factor in most fatalities resulting from motor vehicle crashes. Of the 31,910 passenger vehicle occupants killed in 2000, over half (55 percent) were unrestrained. Forty-three percent of the 1,079 child occupant fatalities, ages 0 through 10 years old, were unrestrained. For child occupants less than 5 years old, 36 percent of the 529 fatalities were unrestrained.
Of the 2,938,000 passenger vehicle occupants injured in crashes in 2000, only 14 percent (409,000) were reported as unrestrained. The rates are about the same for child occupants. For children ages 0 - 10 years old, approximately 165,000 were injured in motor vehicle traffic crashes in 2000, and 13 percent (18,800) of these children were unrestrained. Of the 67,000 child occupants less than 5 years of age who were injured, 10 percent (6,500) were unrestrained.
Child restraints are highly effective in reducing the likelihood of death and or serious injury in motor vehicle crashes. NHTSA estimates ("Revised Estimates of Child Restraint Effectiveness," Hertz, 1996) that for children less than one-year-old, a child restraint can reduce the risk of fatality by 71 percent when used in a passenger car and by 58 percent when used in a pickup truck, van, or sport utility vehicle (light truck). Child restraint effectiveness for children between the ages 1 to 4 years old is 54 percent in passenger cars and 59 percent in light trucks.
Notwithstanding the effectiveness of child restraints certified to Standard No. 213, the agency is continuing to examine whether the safety of children in child restraints can be enhanced even further. In 2000, 256 child occupants under 5 years of age were killed while restrained in child restraints, and another 34,600 were injured. Today's NPRM is part of an effort to reduce these numbers.
On November 27, 2000, we published a planning document that defined our vision for enhancing child passenger safety over the next 5 years (65 FR 70687). The plan contained our views on implementing three strategies for enhancing the safety of child occupants from birth through age 10: increasing restraint use; improving the performance and testing of child restraints; and improving mechanisms for providing safety information to the public. The agency requested comments on the plan and received suggestions on the various initiatives (Docket NHTSA 7938).
Many commenters responded to the second of the three strategies, making suggestions as to how they believed Standard No. 213 should be improved to further enhance child restraint performance. There was general concurrence with the agency's plan to undertake rulemaking with regard to the five elements included today in this NPRM. There was no objection to the agency's then-announced intention to improve side impact protection as a measure that would be pursued internationally in concert with other government and industry bodies. However, it was apparent from the few comments we received on the subject that those commenters considered it to be a long-term project requiring several years of research and development.
After NHTSA completed its draft plan, but before it published the plan in the Federal Register, the TREAD Act was enacted on November 1, 2000. Sections 14 of the TREAD Act directed NHTSA to initiate a rulemaking for the purpose of improving the safety of child restraints by November 1, 2001, and to complete it by issuing a final rule or taking other action by November 1, 2002. The relevant provisions in Sections 14 are as follows:
(a) In General. Not later than 12 months after the date of enactment of this Act, the Secretary of Transportation shall initiate a rulemaking for the purpose of improving the safety of child restraints, including minimizing head injuries from side impact collisions.
(b) Elements for Consideration. In the rulemaking required by subsection (a), the Secretary shall consider--
(1) whether to require more comprehensive tests for child restraints than the current Federal motor vehicle safety standards requires, including the use of dynamic tests that--
(A) replicate an array of crash conditions, such as side- impact crashes and rear-impact crashes; and
(B) reflect the designs of passenger motor vehicles as of the date of enactment of this Act;
(2) whether to require the use of anthropomorphic test devices that--
(A) represent a greater range of sizes of children including the need to require the use of an anthropomorphic test device that is representative of a ten-year-old child; and
(B) are Hybrid III anthropomorphic test devices;
(3) whether to require improved protection from head injuries in side-impact and rear-impact crashes;
(4) how to provide consumer information on the physical compatibility of child restraints and vehicle seats on a model-by-model basis;
(5) whether to prescribe clearer and simpler labels and instructions required to be placed on child restraints;
(6) whether to amend Federal Motor Vehicle Safety Standard No. 213 (49 C.F.R. 571.213) to cover restraints for children weighing up to 80 pounds;
(7) whether to establish booster seat performance and structural integrity requirements to be dynamically tested in 3-point lap and shoulder belts (1);
(8) whether to apply scaled injury criteria performance levels, including neck injury, developed for Federal Motor Vehicle Safety Standard No. 208 to child restraints and booster seats covered by in [sic] Federal Motor Vehicle Safety Standard No. 213; and
(9) whether to include [a] child restraint in each vehicle crash tested under the New Car Assessment Program.
(c) Report to Congress. If the Secretary does not incorporate any element described in subsection (b) in the final rule, the Secretary shall explain, in a report to the Senate Committee on Commerce, Science, and Transportation and the House of Representatives Committee on Commerce submitted within 30 days after issuing the final rule, specifically why the Secretary did not incorporate any such element in the final rule.
(d) Completion. Notwithstanding any other provision of law, the Secretary shall complete the rulemaking required by subsection (a) not later than 24 months after the date of the enactment of this Act.
Each of the initiatives contemplated by the TREAD Act as possible upgrades to Standard No. 213 were included in the agency's plan as possible candidates for rulemaking to enhance the performance of child restraint systems. (2) Notwithstanding the effectiveness of child restraints certified to Standard No. 213, the thrust of the 5-year plan was to consider possible rulemaking that could enhance the performance of child restraints even further. Enhancements were considered in terms of improved crash protection and in terms of increased usability of the restraints so that misuse is reduced. At the same time, we believed then, and continue to do so now, that in making regulatory decisions on possible safety enhancements, the agency must bear in mind the consumer acceptance of cost increases.
Weighing all these factors, the agency has tentatively decided that safety enhancements are warranted in the aspects of the child1 restraint standard discussed below in section IV.
III. EXISTING REQUIREMENTS OF STANDARD NO. 213
The following discussion summarizes current provisions in Standard No. 213 relating to the performance of child restraint systems.
l. The performance of a child restraint system is evaluated in dynamic tests involving a 30 mph velocity change, which is representative of a severe crash. Each child restraint is tested while attached to a standardized seat assembly. Restraints are tested while attached to the standard seat assembly by various means. The restraint system is anchored to a test seat with a lap belt only, or a lap/shoulder belt if the restraint system is a booster seat designed for these belts. In another test, the child restraint is required to meet more demanding requirements with respect to the permissible forward motion of the dummy's head, which is typically accomplished by use of a tether attached to the top of the child restraint. Beginning in 2002, child restraints will also be subjected to frontal crash simulations when anchored to the test seat assembly by a new child restraint anchorage system (49 CFR §571.225) (3). Built-in child seats are evaluated by crash testing the vehicle they are built into, or by simulating a crash with the built-in seat dynamically tested with parts of the vehicle surrounding it.
2. To protect the child, limitations are set on the amount of force that can be exerted on the head and chest of a child test dummy during the dynamic testing. (S5.1.2 of Standard No. 213). To reduce the possibility of injury that child occupants in child restraint systems may incur if they contact vehicle interior surfaces during a crash, limitations are also set on the amount of frontal head and knee excursions that can be experienced by the test dummy. To prevent a child from being ejected from rearward-facing restraints (e.g., infant restraints), limitations are set on the amount that such restraints can tip forward (S5.1.4 of Standard No. 213).
3. During dynamic testing, no load-bearing or other structural part of any child restraint system may separate so as to create jagged edges that could cut and injure a child. If the child restraint has adjustable positions, it may not shift positions if doing so could potentially catch a child's limbs between the shifting parts or allow the child to "submarine" (i.e., allow the child to slide down and out of the restraint during a crash) (S5.1.1 of Standard No. 213).
4. To prevent injuries to children during crashes from contact with the surfaces of the child restraint itself, the standard specifies requirements for the size and shape of those surfaces. In addition, protective padding requirements are set for restraints designed for use by infants (S5.2 of Standard No. 213). The standard specifies a minimum surface area for those surfaces that support the side of the child's torso. Each surface must be flat or concave and have a continuous surface of not less than 24 square inches for systems recommended for children weighing 20 lb or more, or 48 square inches for systems recommended for children weighing less than 20 lb (S220.127.116.11(b)).
5. The belts, buckles, and attachment hardware used in child restraint systems have to meet abrasion and corrosion resistance requirements (S5.4.1 and S5.4.2). Additionally, the belts in child restraints must adjust to snugly fit occupants, not transfer any crash loads from the vehicle to the child, and must restrain the child's upper and lower torso (S5.4.3 of Standard No. 213).
6. The amount of force necessary to open belt buckles and release a child from a restraint system is specified so that children will not be able to unbuckle themselves, but adults will be able to do so quickly and easily (S18.104.22.168 and S6 of Standard No. 213).
7. Information necessary for the proper use of the child restraint system must be permanently labeled on the child restraint and presented in an information booklet that accompanies the child restraint system. The child restraint must also provide a special location or compartment on the child restraint system in which the information booklet may be permanently stored, so that the parent or other user of the child restraint can always have available the necessary safety information (S5.5 of Standard No. 213). Standard No. 213 also requires each child restraint system to be accompanied by a postage-paid registration form so that purchasers can register with the manufacturer and thereby be directly notified in the event of a safety recall. Manufacturers must retain the names and addresses of registrants for a period of six years. (S5.8 of Standard No. 213; 49 CFR Part 588).
8. Each material used in a child restraint system must meet the flammability requirements of S4 of FMVSS No. 302 (49 CFR §571.302) (S5.7 of Standard No. 213).
9. Beginning September 1, 2002, child restraint systems must have components permanently attached to them that will enable them to be anchored to a new child restraint anchorage system that will be standard on all new passenger vehicles. The vehicle anchorage system consists of two bars that are at or close to the intersection of the vehicle seat cushion and seat back, and a top tether anchorage located typically (a) on the rear shelf below the rear window in passenger cars, or (b) on the floor or on or under the seat structure of sport utility vehicles and minivans. Child restraints will still be capable of being anchored to the vehicle seat by the vehicle seat belts.
10. Child restraints certified for use in both motor vehicles and aircraft must pass an additional test when attached to a representative airplane seat, and provide additional information on the proper use of the restraint system in an airplane seat (S8 of Standard No. 213).
IV. ANPRM ON SIDE IMPACT PROTECTION
In an advance notice of proposed rulemaking (ANPRM) published concurrently with today's NPRM, we are seeking public comments on the agency's work on developing a possible side impact protection standard for child restraint systems and on possible refinements to the approach we have taken thus far. In its review of the child restraint standard in response to the TREAD Act, NHTSA placed particular emphasis on improving the ability of child restraints to provide protection in side impact crashes. Although we have conducted extensive testing and analysis over the past year aimed at providing additional side impact protection for children in child restraints, there are many unknowns. We seek comment on the suitability of the test procedures we are considering, on appropriate injury criteria for children in side impacts, on cost beneficial countermeasures, and on other issues. The agency anticipates that comments to the advance notice will help us assess the benefits and costs of a side impact rulemaking, which will help us decide whether to issue a notice of proposed rulemaking in the near future and/or identify the work that needs to be done.
V. AGENCY PROPOSALS
a. Updated Bench Seat
This NPRM proposes to update the standard vehicle seat assembly used in Standard No. 213's dynamic testing. The original seat assembly was developed in the mid-1970's by the Highway Safety Research Institute at the University of Michigan. The bench seat was based on the configuration and performance parameters of the 1974 Chevrolet Impala production front bench seat. Static and dynamic characteristics of the production seat were modeled into the frame deformation and foam stiffness of the standard seat.
NHTSA proposes to update the following features of the seat assembly: the seat bottom cushion angle would be increased from 8 degrees off horizontal to 15 degrees; the seat back cushion angle would be increased from 15 degrees off the vertical to 22 degrees; the spacing between the anchors of the lap belt would be increased from 222 millimeters (mm) to 392 mm in the center seating position and from 356 mm to 472 mm in the outboard seating positions; and the seat back of the seat assembly would be changed from a flexible seat back to one that is fixed, to represent a typical rear seat in a passenger car. Figures 1A, 1B and 1B' of Standard No. 213 would be revised to reflect these changes, as would the drawing package of the seat assembly (SAS-100-1000, with Addendum A, dated October 23, 1998) that is incorporated by reference (see 49 CFR §571.5) into the standard.
This proposal is based on evaluations we have made regularly over the years, and most recently this year in response to the TREAD Act, of the need to update or improve the seat assembly used for testing child restraints. There is no question that the seat assembly should be representative of production seats to the extent possible so that a child restraint's true performance in a crash can be assessed. However, while to the extent possible it may be desirable for the seat assembly to mirror production seats, our program work developing and evaluating the standard seat assembly was guided by a number of additional considerations. The seat assembly must be durable and must contribute to obtaining repeatable and comparable test results for child restraints. Meeting the performance requirements of Standard No. 213 on the test seat should ensure that child restraints performed adequately on the variety of different seats found in cars on the road. In comparison to some vehicle seats, the test seat might present more demanding test conditions, but this was acceptable if the test seat were representative of many seats used in vehicles. Differences between the standard seat assembly and production seats could be disregarded if the differences did not affect child restraint performance on the seat. The seat assembly did not need to conform to non-identical features that were unlikely to have a confounding effect on child restraint performance.
These considerations counseled against changing the seat assembly significantly in the past. Child restraints were performing well in the field. The few features that we thought could be updated, such as the seat assembly's cushion angle and seat back angle, were not thought to affect safety sufficiently to warrant use of the agency's limited resources for that purpose. We were also concerned about possible cost increases to child restraints that might occur as some manufacturers passed on the costs of possibly having to retest all child restraints on the market.
With the passage of section 14(b) of TREAD, Congress has presented its belief that the seat assembly should be updated to reflect the designs of production seats. We concur with considering the issue further. We have identified a number of features of the present seat assembly that could be updated, which are discussed below. Later this year, NHTSA will undertake an assessment of what effect, if any, the updated seat assembly might have on the performance of child restraints.
2. Post-TREAD Rulemaking Support Program
In response to TREAD, NHTSA initiated a test program to assess seat parameters of production seats, working with Veridian Engineering (Veridian) and the U.S. Naval Air Warfare Center Aircraft Division at Patuxent River, Maryland (PAX). Veridian gathered information on geometry and stiffness of seats of vehicles tested in NHTSA's 2001 New Car Assessment Program (NCAP). PAX analyzed the seat geometry data, including seat cushion angle, seat back angle, seat cushion length, seat back length, tether anchor locations, child restraint anchorage system anchor locations, and seat belt locations. A report by PAX on the project is available in the docket. This preamble provides an overview of the results. Readers are referred to the report for a detailed explanation of the methodology used in the test program, and the results of each parameter, sorted by vehicle class.
To summarize the report, the research program analyzed the seat geometries of 35 vehicles. Because of time constraints and the fact that the test for determining force/deflection characteristics of the vehicle seat is a destructive test (that is, a section of the seat cushion had to be cut out and removed), the agency utilized vehicles that had previously undergone testing in the agency's New Car Assessment Program program but whose rear seats had not been destroyed or discarded. Every attempt was made to obtain vehicles from a range of vehicle classes for evaluation. Of these vehicles, 19 were passenger cars, 11 were SUVs, 4 were minivans, and 1 was a pickup truck. PAX analyzed the various seat geometry measurements of the vehicles, by seating position (outboard or middle) and vehicle class, and identified some features of the bench that do not reflect current vehicle designs.
We have tentatively determined that a number of those features should be changed, that some others need not be, and that a few features (e.g., seat cushion stiffness) require further analysis before we can decide whether we should change them. Generally, where there is a notable difference between the existing seat assembly and the fleet, the agency has proposed changing the seat assembly to make it more representative of the existing vehicle fleet.
We request comments on the proposal, particularly with regard to the latter category. NHTSA will be conducting further analyses of some of the proposed changes, since the analyses could not be completed in time for this NPRM. Information we obtain will be placed in the docket. Further, later this year, NHTSA will be evaluating dynamically most of the changes that we propose to make to the seat bench, to ensure that these changes do not result in compromising the safety currently afforded by child restraints. Results of this testing will be compared to compliance test data of existing child restraints to evaluate the effect of the changes. Comparison of these tests will aid in the agency's decision regarding whether to adopt the proposed changes in a final rule.
3. Features That Should Be Changed
i. Bottom Seat Cushion Angle.
Currently, the seat assembly has a seat pan angle of 8o off horizontal. In the 35 vehicles surveyed, 77 seat pan angle measurements were made of rear seats, from either the outboard position or the center position, or if the vehicle had a third seating position, from that position as well. PAX found that 39% of the seat pan angle measurements were within 16o to 20o off horizontal and 35% of the seat pan angle measurements fell within 11o to 15o of horizontal. The test data show an average seat pan angle of 15.5o. We have tentatively decided that the seat pan angle of the seat assembly should be increased to 15o off horizontal. A 15o angle would be in accordance with the bottom seat cushion angle specified by ECE Regulation 44.
Comments are requested on the effect of this change on the performance of child restraints in actual vehicles. In a September 18, 2000 petition for rulemaking, Ford Motor Company indicated that using the ECE Regulation 44 seat cushion angle would solve a problem it has found using the present seat assembly to test "rear-facing child restraint systems (CRS) equipped with rigid Lower Anchors and Tethers for Children (LATCH) system attachments." Under Standard No. 213, child restraints may use rigid attachments to connect to the lower anchorage bars of LATCH systems, or may use non-rigid attachments (such as those attached to the child restraint by webbing material). Ford believed that the seat cushion angle of the seat assembly is driving the design of rear-facing child restraints. Because the current seat assembly is flatter than actual vehicle seats, when infant restraints are installed on actual vehicle seats, the restraints are installed at an overly steep angle. Ford stated that the overly steep angle can be corrected in conventional restraints by tipping the restraint back and placing a rolled towel under the base, near the seat bight. However, an infant restraint with rigid LATCH attachments will not have any flexibility that will allow it to be tipped backwards while remaining connected to the lower anchorage bars. To solve this problem, Ford suggested using the ECE Regulation 44 seat assembly, which has a 15o bottom seat cushion angle, modified to have the LATCH anchorage bars included in the assembly. (4)
ii. Seat Back Angle.
Currently, the seat assembly has a seat back angle of 15o off vertical. Seventy-eight seat back angle measurements of rear seats in the 35 vehicles surveyed were taken from either the outboard or center seat position, or, if available, the third seating position. From this analysis, the average seat back angle for all measurements taken is 22o off of vertical. This is an increase of 7o over the current angle specified for the FMVSS No. 213 seat assembly. Forty-four percent of all the measurements taken yielded seat back angles between 21o and 25o. For these reasons, NHTSA proposes increasing the angle to 22o.
iii. Seat Belt Anchors.
The current seat assembly has a lateral spacing of 222 mm between the lap belt anchors in the center seating position, and a lateral spacing of 500 mm for the outboard seating positions. Based on the evaluation of the 35 vehicles surveyed, the average lap belt anchor spacing in center seating positions in the modern vehicle fleet is 392 mm. Thirty-nine percent of the measurements taken for the center seating position fell in the range of 351 mm to 400 mm, while 63 percent of the measurements were between 301 mm and 400 mm. As such, the current seat assembly represents a distance that is 170 mm smaller than that of the current vehicle fleet. We propose increasing the spacing to 392 mm for the center seating position to represent the average of the current vehicle fleet. Based on the evaluation of the 35 vehicles surveyed, the average lap belt anchor spacing in the outboard seating positions is 472 mm, as compared to 500 mm on the current Standard No. 213 standard seat assembly. Thirty-three percent of the measurements taken were greater than 500 mm, while 90 percent were above 400 mm. As the average anchorage spacing for outboard seating positions in the modern vehicle fleet is 28 mm less than that on the current standard seat assembly, we propose to change the spacing to 472 mm to more accurately represent actual vehicles. Comments are requested on how changing the spacing will affect the performance of a child restraint in dynamic tests.
iv. Fixed Seat Back.
NHTSA proposes that the seat back of the seat assembly be changed to represent a fixed vehicle seat. Steel rods should replace the existing aluminum rods. A fixed seat back will be more representative of the rear seat of today's passenger cars, and would harmonize with ECE regulations. Because NHTSA strongly recommends that children under the age of twelve ride in the back seat, changing the seat assembly to represent a typical rear seat seems appropriate. However, vans and multipurpose vehicles with multiple seating rows may be more closely represented by a flexible seat back. Comments are requested on this issue. NHTSA is currently evaluating the effect of the change on child restraint performance by use of MADYMO simulations, and will further study the effect of flexible versus rigid seat backs through sled testing to be performed later this year.
4. Features That Need Not Be Changed
NHTSA has tentatively decided that the following features of the bench seat need not be changed because they either reflect the design of production seats or are different but that difference is deemed not to have an effect on child restraint performance in dynamic testing. Comments are requested on these features.
i. Bottom Seat Cushion Length.
Currently, the seat assembly has a bottom seat cushion length of 508 mm. In order to find the average bottom seat cushion length, 78 measurements were taken in the 35 vehicles surveyed. Analysis depicts the average seat pan length as 461 mm. The average bottom seat cushion length for 64% of the measurements was found to lie within the range of 451 mm to 500 mm. Therefore, the current FMVSS No. 213 seat assembly has a seat pan length that is about 50 mm longer than the average seat pan length observed in today's vehicle fleet. We do not believe that this difference is consequential, as the reduced seat cushion length does not cause an incompatibility with existing child restraint designs.
ii. Seat Back Height.
Currently, the 213 seat assembly has a seat back height of 610 mm. In the 35 vehicles surveyed, 78 measurements of the height of the seat back were made in both the outboard and center positions. These data yield an average seat back height of 619 mm. The highest percentage of seat back length measurements fell within the range of 601 mm to 700 mm. This percentage represented 64% of the vehicle measurements. Because the Standard No. 213 seat assembly is only 9 mm lower than the average seat back height observed in today's fleet, we do not see a need to propose to raise the height of the seat back.
iii. Test Bench Floor.
In response to the agency's draft Child Protection System Safety Plan, Ford recommended that the standardized bench seat should have a floor (see Docket 7938-20). Ford believed that the current test seat assembly cannot evaluate a rear-facing child restraint that is equipped with a support leg, as has been developed and is currently used in other countries. We are declining to add a floor to the test assembly at this time, since Standard No. 213 does not allow support legs in compliance testing. Under Standard No. 213, rear-facing restraints are only to be attached to the seat assembly via the lap belt or the anchorages of the LATCH system. As such, the inclusion of a floor structure on the Standard No. 213 standard seat assembly is not necessary at this time.
5. What About Cushion Stiffness?
Comments are requested on whether the seat assembly's cushion should be made stiffer. PAX found the average stiffness of the Standard No. 213 seat assembly to be marginally softer than most, but not all new vehicles on the road today. The force deflection curves generated by PAX show that the current Standard No. 213 seat cushion is softer at both the fore and aft outboard positions than almost all seat cushions in vehicles of the modern fleet. As part of the work performed in 1988 to reexamine the Standard No. 213 procedures, (5) the stiffness characteristics of the Standard No. 213 seat cushion material were compared with the characteristics of then current model vehicle seats. Static force versus deflection tests were conducted on the Standard No. 213 seat cushion foams, and these curves were then compared with similar curves that had been developed for ten vehicles which had been measured in a separate project in 1987. The distribution of force versus deflection curves found in that evaluation closely parallel those found by PAX, in that most vehicle seats were stiffer than the Standard No. 213 seat assembly, but there was at least one vehicle seat that was softer. Sled tests were performed in 1988 to compare the dummy response of the Standard No. 213 seat cushion, a representative cushion that was softer, and a stiff cushion. The dummy response differences were not sufficiently large or consistent to warrant specifying a different cushion than the foam used in Standard No. 213. Thus, the Standard No. 213 cushion was considered to be "representative" of the rear seats of then current cars.
We are interested in increasing the stiffness of the cushion, but are uncertain what, if any, differences will be seen in dynamic testing. We request comments on what the stiffness should be. Comments are also requested on what effect changing the test seat stiffness would have on child restraint performance in dynamic testing.
c. Crash Pulse
This NPRM would slightly revise the Standard No. 213 pulse. We propose to extend the pulse to approximately 90 milliseconds (msec), and to widen the test corridor to make it easier for more test facilities to reproduce it. The expanded corridor would not reduce the stringency of the test, and would also make it easier to conduct compliance tests at speeds closer to 30 mph. We found in studying vehicle crash pulses that the Standard No. 213 pulse is more severe than most other pulses, but is similar to crash pulses of large sport utility vehicles and light trucks--passenger vehicles that are becoming more and more popular for use as family vehicles--and very similar to the crash pulse of small school buses.
1. The Current Crash Pulse
In Standard No. 213's dynamic sled test, a test dummy is secured in a child restraint, which in turn is attached to a representative vehicle bench seat (seat assembly). The assembly is then subjected to acceleration to simulate a vehicle crash. The child restraint must manage the force from the simulated crash so that the forces imparted to the dummy are within tolerable limits. The force imposed on the child restraint and dummy is a function of the acceleration onset rate, peak, and duration. Paragraph S6.1.1(b)(1) of Standard No. 213 specifies that when child restraints are tested in the 48 km/h (30 mph) dynamic test, the acceleration of the test platform must be entirely within the curve shown in Figure 2 of the standard. (6) "Crash pulse" refers to the change in the sled's velocity over time. The severity of a crash pulse is a function of its onset rate, peak g and its time of occurrence, and duration. The standard has a relatively severe crash pulse, in that the sled is accelerated relatively quickly to an acceleration of approximately 24 g's (24 times the force of gravity) and maintains the 24 g level for a relatively long time period (37 to 42 msec) before returning to zero acceleration.
Pulses can vary as to their shape, onset rate, peak acceleration, and duration. NHTSA's research in the mid-1990's showed that Standard No. 213's pulse was more severe than the "average car" pulse of 1988-1991. Crash pulses obtained from Standard No. 208 vehicle crash tests indicated a peak G occurring much later in the crash event compared to Standard No. 213 and a longer pulse duration. The upper limit of the Standard No. 208 pulse ended at 135 msec, compared to 81 msec for the Standard No. 213 pulse.
Since the mid-1970's, vehicle front ends of passenger cars have become softer, allowing for more front-end crush to take place. This results in crash pulses that are much longer in duration than car crash pulses of 30 years ago. Current cars have crash pulses that are generally longer in duration than that of Standard No. 213. The peak G's are similar, so the longer duration means that the average model year 2001 passenger car has a less severe pulse than the standard. (7) Because of these changes in car design, we have been asked to reconsider the crash pulse in Standard No. 213 to ensure that it is representative of the crash pulses of today's vehicles. See, e.g., Ford's comment on NHTSA's draft Child Restraint Systems Safety Plan, docket 7938-20.
We have also been asked to re-examine the crash pulse because it is difficult to duplicate due to the narrow corridors in the laboratory test procedure. Very few labs are able to replicate the 213 pulse. Transportation Research Center (TRC), a testing laboratory, submitted a petition to NHTSA on October 6, 1999, which we granted, regarding the pulse corridor specified in the laboratory test procedure for Standard No. 213. Due to features of the TRC sled and others of its type generally (HYGE), TRC stated that there is a problem with achieving the acceleration curve specified in the standard and suggested that the pulse can be slightly revised, by manipulating time zero, to accommodate HYGE sleds without affecting test results.
Standard No. 213 specifies that, when testing child restraints in the 48 km/h test, the acceleration of the test platform must be entirely within a specified curve. The curve begins at zero g's and zero time. TRC stated that its HYGE sled is generally unable to produce the required acceleration curve. The sled "fires" by cracking a seal between a high pressure chamber and a low pressure chamber, with the flow of gas (around a metering pin, which controls acceleration curve shapes) from high pressure to low pressure providing the acceleration force. TRC explained that initially, the area available for gas flow is small, and a short amount of time is required for pressure to build enough to cause significant acceleration. Because there is a lag time between initiation of the test and appreciable acceleration of the sled, when the curve begins at zero g's and zero time, a significant portion of the curve is not within the tolerance band required by the present test procedure. When time zero is manipulated so that the initial acceleration pulse falls within the zero to 10 millisecond envelope, and the acceleration at time zero is 1.25 g's, the required tolerance band is achieved.
We have determined that TRC's petition merits consideration. In December 1998, NHTSA issued a final rule amending the sled test requirement in Standard 208, "Occupant Crash Protection," by, among other things, revising how time zero is defined (63 FR 71390, December 28, 1998). The sled test in that standard tests occupant response for air bag restraint systems. In that rulemaking, NHTSA determined that it is impractical for that test to have time zero at 0.0 g acceleration, because of the time lag between initial movement of the sled and significant acceleration. The agency decided that the start of the sled test will be determined by a specific acceleration level for the sled which corresponds to a time at which the most rapid acceleration begins, at about 0.5 g's (63 FR at 71393). Similarly, TRC would like NHTSA to revise its pulse envelope specifications for child restraint testing to allow a small deviance at time zero "so that . . . sleds [similar to TRC's] may defendably participate in certification and compliance testing."
2. The Crash Pulse Is Not Overly Severe
Following passage of the TREAD Act, NHTSA had PAX analyze the crash pulses of over 150 vehicles tested under FMVSS No. 208 and under the agency's frontal New Car Assessment Program (NCAP). Based on the analysis of model year (MY) 1995 to MY 2000 vehicles, PAX found that the current pulse in Standard No. 213 was more severe (8) than that of most passenger vehicles in today's fleet, but was similar to the pulses of truck and truck-like multipurpose passenger vehicles (i.e., large sport utility vehicles, SUVs) in Standard No. 208 tests, except that the truck pulse was much longer in duration than the Standard No. 213 pulse. A report by PAX on the research project is available in the docket.
To summarize the report, PAX obtained "average" crash pulses from the FMVSS No. 208 vehicle crash tests and NCAP tests. To obtain average NCAP and FMVSS No. 208 pulses, 59 vehicles were separated into 4 classes: cars, SUV's, trucks, and vans. The pulses were then filtered, and the peak velocity, peak G, and duration of the crash pulse were recorded.
The Society of Automotive Engineers (SAE) Recommended Practice for electronic processing of vehicle crash test acceleration data, as given in SAE J211, is Channel Frequency Class 60. Filtered at SAE J211 Class 60 (100 Hz cutoff frequency), the average car pulse had a peak acceleration of 24 g's at 70 msec and pulse duration of approximately 115 msec. When this pulse was overlaid with the Standard No. 213 pulse, the 213 pulse enclosed no portion of the average car curve. The average car had an initial slope similar to FMVSS No. 213, but then the vehicle began to crush before stiffening up again. For vans, the average van pulse had a peak acceleration of 22 g's at 42 msec and pulse duration of 140 msec. Both the van pulse and the 213 pulse had almost identical rise times, but then after 10 msec, the van pulse began to behave like the car pulse. However, small portions of the van pulse were enclosed by the 213 pulse corridor.
With SUV's, the average SUV pulse had a peak acceleration of 26 g's at 27 msec and a pulse duration of 113 msec. When the SUV pulse was overlaid with the 213 corridor, the time of peak G for the SUV pulse was very similar to the 213 pulse, which peaks at 20 msec, and the rise time between the two pulses was also very similar. Portions of the SUV pulse fell within the 213 corridor a number of times.
For pick-up trucks, the average truck pulse had a peak acceleration of 26 g's at 24 msec and a pulse duration of 114 msec. When the truck pulse was overlaid with the 213 corridor, there were many similarities. Not only did the two curves peak at almost the same time but the rise time was very similar. Also, for the first 65 msec, the truck pulse fell within the corridors of 213 many times. Although the duration of the pulse was different, the truck pulse and the 213 pulse appeared to be very similar.
A summary of the PAX findings are set forth in Table 4.
Table 4: Summary of PAX Pulse Data filtered at SAE Class 60 (100 Hz)
|Pulse Type||Peak G||Time (msec)||V (kph)|
|Average Passenger Car||24||115||31||55|
|FMVSS No. 213||21||81||20||48|
Based on this information, we have decided not to reduce the severity of Standard No. 213's crash pulse. PAX found that the current crash pulse is very similar to the pulse of light trucks, SUVs and small school buses in acceleration onset rate and peak magnitude.
Figures 2, 3 and 4 plot acceleration curves of SUVs, trucks, and a small school bus. These plots show that the existing Standard No. 213 pulse corridor closely represents pulses of these vehicles. As shown in the figures, the first 70 msec represents several modern day vehicles used to transport children. Increasingly, light trucks, SUVs and small school buses are being used to transport children in child restraints. Based on these findings, we conclude that the stringency of the FMVSS No. 213 crash pulse is justified to better ensure that each child restraint will not have structural degradation in a crash, and will limit forces to the head, neck, and torso to tolerable levels, no matter the vehicle the child is in.
The agency is seeking comment on whether a more severe crash pulse should be established for testing child restraint systems. Comments are sought on the trapezoidal-shaped corridor proposed, and on the parameters that determine the level of severity of a pulse for child restraint systems. Does the trapezoidal-shaped corridor provide a sufficient representation of the current vehicle fleet, or are there other pulse shapes that would be more representative and/or more severe?
The agency is also seeking comment as to whether the total change of velocity of the current Standard No. 213 pulse (delta v = 30 mph) should be increased to 33 mph to be equivalent to a 30 mph crash into a rigid barrier. Typically, a delta v of 33 mph is seen in a 30 mph rigid wall test required for adult protection in Standard No. 208.
3. Adjusting the Corridors of the Pulse
We are proposing minor revisions to the crash pulse. We would extend it to approximately 90 msec, and would widen the test corridor so that several testing facilities can satisfactorily reproduce the FMVSS No. 213 crash pulse (see figure 5). The expanded corridor would not sacrifice the stringency of the current pulse. The proposal would ensure the rapid rise as is currently in the standard but also accommodate small deviations at time zero as requested by the TRC petition. The change in the boundary of the corridor would provide laboratories the flexibility to generate a pulse that would be closer to a V = 30 mph.
NHTSA proposes that the sled pulse for Standard No. 213 (see figure 5, above) should have the coordinates given in the following table 5:
Table 5: Proposed Sled Pulse Coordinates
|Upper Bound||Lower Bound|
NHTSA will be further evaluating the proposed changes. Sled tests using the proposed crash pulse will be conducted later this year, and the information we obtain will be placed in the docket. Results of this testing will be compared to compliance test data of existing child restraints to evaluate the effect of the changes. Comparison of these tests will aid in the agency's decision as to whether the proposed changes should be adopted in a final rule.
d. Improved Child Test Dummies
This document proposes two initiatives toward enhancing the use of test dummies in the evaluation of child restraints under Standard No. 213. NHTSA proposes to replace some of the existing dummies with improved dummies representing children of approximately the same age as the replaced dummies. NHTSA also proposes testing child restraints for older children by using a weighted 6-year-old dummy (i.e., a dummy to which weights have been added). The total weight of the dummy would be 62 lb. The weighted dummy would be used to test child restraints that are recommended for children weighing 50 to 65 lb. (This NPRM also proposes expanding the applicability of Standard No. 213 to restraint systems recommended for use by children weighing up to 65 lb. See section IV(e) of this preamble.)
Child restraint systems must be certified as meeting Standard No. 213's requirements when dynamically tested with test dummies that represent children of different ages. The current dummies used in Standard No. 213 compliance testing are the uninstrumented newborn infant, the uninstrumented 9-month-old infant, and the Hybrid II 3- and 6-year-old dummies. NHTSA selects which test dummy to use based on the mass of the children for whom the manufacturer recommends for the child restraint. Table 6 sets forth which dummies are used to test child restraints based on the mass recommendations established for the restraint by the manufacturer. If a child restraint were recommended for a range of children whose mass overlaps, in whole or in part, two or more of the mass ranges in the table, the restraint is tested with the dummies specified for each of those ranges. Thus, for example, if a child restraint were recommended for children having masses greater than 13 kg and up to 20kg, it would be tested with the 9-month-old dummy, the 3-year-old dummy and the 6-year-old dummy.
TABLE 6: Use of Current Dummies
Recommended Mass Range (Kilograms) Dummy(ies) Currently Used in Compliance Testing Not greater than 5 kg (0 to 11 lb) Newborn Greater than 5 but not greater than 10 kg (11 to 22 lb) Newborn, 9-month-old Greater than 10 but not greater than 18 kg (22 to 40 lb) 9-month-old, Hybrid II 3-year-old Greater than 18 (40 to 50 lb) Hybrid II 6-year-old
1. CRABI, Hybrid III Dummies
i. Replacing Current Dummies
The first initiative is a proposal to replace three of the test dummies now used in Standard No. 213 compliance tests with new test dummies. The design and performance criteria for the new dummies were incorporated into NHTSA's regulation for anthropomorphic test devices, 49 CFR Part 572, by rulemaking actions concluded last year. The new dummies are the Child Restraint Air Bag Interaction (CRABI) 12-month-old infant dummy (Part 572, Subpart R), the Hybrid III 3-year-old child dummy (Subpart P), and the Hybrid III 6-year-old child dummy (Subpart N). The dummies are used in compliance tests that the agency adopted last year for testing advanced air bag systems under Standard No. 208, "Occupant Crash Protection." We would retain the newborn infant dummy in Standard No. 213's compliance tests, but would replace the 9-month-old dummy (Part 572, Subpart J) with the CRABI. (9) We would replace the Hybrid II 3- and 6-year-old dummies with their Hybrid III (HIII) counterparts. Thus, just as in the protocol today under Standard No. 213, there would be four child test dummies used for compliance testing.
The new dummies were incorporated into Part 572 because they comprise a new generation of test dummies that are more representative of human children than their Hybrid II counterparts, and allow for the assessment of the potential for more types of injuries in motor vehicle crashes. The biofidelity, reliability and repeatability of the test dummies were discussed in the final rules incorporating the dummies into Part 572. See, final rules for the CRABI (65 FR 17188; March 31, 2000); Hybrid III 3-year-old (65 FR 15254; March 22, 2000); Hybrid III 6-year-old dummy (65 FR 2065; January 13, 2000). The CRABI dummy is instrumented with head, neck and chest accelerometers, while the 9- month-old dummy is not. The Hybrid III child dummies have a broader selection of instruments to assess the injury potential to child occupants, including a multi- segmented neck, multi-rib thorax and abdominal load monitors, while the Hybrid II dummies have limited biofidelity in the neck area and are not instrumented to measure neck injury. Because of their superior instrumentation, the CRABI dummy and the Hybrid III child dummies can provide a fuller evaluation of the performance of child restraint systems in protecting young children.
Simply substituting the dummies for the existing ones might not, in itself, affect child restraint performance. There does not seem to be a significant difference between the Hybrid II and Hybrid III dummies in their ability to measure head and chest accelerations or in dummy kinematics relevant to head and knee excursions. A series of frontal, Standard No. 213 sled tests were conducted to evaluate the equivalency between the Hybrid II child dummies currently used in the standard with the CRABI dummy and the Hybrid III 3- and 6-year-old dummies. Results from previously performed compliance tests (Hybrid II dummies) were identified, and the Hybrid III and CRABI dummies were seated in various CRS and vehicle belt configurations in order to establish a full complement of tests with both the Hybrid II and Hybrid III dummies. Where needed, additional sled tests were performed with the Hybrid II dummies. HIC, chest acceleration, and head and knee excursion values were compared between the Hybrid II and Hybrid III dummies for each age group. Test results indicate similar performance between the Hybrid II and Hybrid III child dummy families. See, "A Comparative Evaluation of the Hybrid II and Hybrid III Child Dummy Families," a copy of which has been placed in the docket. Nonetheless, replacing the Hybrid II 3- and 6-year-old dummies with their Hybrid III counterparts would enhance safety by the latter's greater instrumentation capabilities and improved biofidelity, and by the adoption of injury criteria that the Hybrid II dummies cannot measure. This NPRM proposes new injury criteria of that sort, which are discussed in section V (f), infra.
ii. Retaining the Criteria Used to Determine Which Dummy Is Used in Compliance Tests
NHTSA proposes to retain the criteria that are used to determine which dummy is used in Standard No. 213's compliance test. Table 7 sets forth the dummies that would be used to test child restraints, based on the mass of the children for whom the restraint is recommended.
TABLE 7: Proposed Use of New Dummies
Recommended Mass Range (Kilograms) Dummy(ies) Currently Used in Compliance Testing Dummies Proposed for Use Not greater than 5 kg (0 to 11 lb) Newborn Newborn Greater than 5 but not greater than 10 kg (11 to 22 lb) Newborn, 9-month-old Newborn, CRABI Greater than 10 but not greater than 18 kg (22 to 40 lb) 9-month-old, 3-year-old CRABI, HIII 3-year-old Greater than 18 kg but not greater than 22.7 kg (40 to 50 lb) 6-year-old HIII 6-year-old Greater than 22.7 kg (Over 50 lb) --- Weighted HIII 6-year-old
Comments are requested on the merits of replacing the existing dummies with the three new ones. The agency has tentatively decided that it would no longer use the 9- month-old dummy (which weighs 20 lb) to test child restraints because the newborn and the CRABI (22 lb) appear sufficient to evaluate the performance of a child restraint recommended for infants. Comments are requested on whether the 9-month-old dummy would still be needed to test child restraints, and if so, which restraints should be tested with that dummy. The 9-month-old dummy better represents a 9-month-old child than the CRABI, since the CRABI is slightly more massive as a device representing a 12-month-old. Thus, retaining the 9-month-old in compliance testing might increase the scrutiny of the standard of infant restraints, which argues for continued use of the dummy in compliance tests (although there would be costs associated with such use). Also, some rear-facing infant car seats/carriers that are designed with a handle for toting the infant outside of the vehicle are recommended for use with infants weighing only up to 20 lb. Even though the CRABI (at 22 lb) is heavier than the children recommended for those restraints, we tentatively conclude that the CRABI can and should be used in compliance tests of these restraints because it is instrumented and the 9-month-old (20 lb) dummy is not. Do all infant car seat/carriers have back supports that are high enough to support the CRABI?
Relatedly, the agency's policy has been, to the extent possible, to test each child restraint with dummies that are at the ends of the weight range of children for whom the restraint is recommended. The smaller of the two dummies with which we test child restraints is used for assessing the potential for ejection, while the larger dummy is used for assessing structural integrity. Be that as it may, we would test a child restraint that is recommended for use by children weighing 20 to 40 lb forward-facing with the CRABI (22 lb) dummy, and not with the 9-month-old (20 lb) dummy, even though the 9-month-old dummy is closer in weight/mass to the lower end of the recommended weight range for the restraint. The difference in stature between the 9-month-old and the 12- month-old CRABI is nominal--the 9-month-old is 27.9 inches tall, while the 12-month-old CRABI is 29.4 inches tall (the sitting heights are 17.7 inches and 18.3 inches, respectively). As such, both dummies will likely provide nearly identical measures of the possibility for ejection. Comments are requested on this issue.
Comments are requested on whether there is a need to specify in Part 572 a test dummy representing an 18-month-old child. Transport Canada has evaluated an 18-month-old CRABI child dummy that weighs 25 lb. However, because NHTSA has not evaluated the dummy, we have not assessed whether it should be used in compliance testing. There also does not appear to be a significant need for the dummy. The dummy would be used in tests of convertible (10) restraints that are recommended for use in the rear-facing configuration by children weighing over 22 lb. As noted above, restraints that are recommended for use by children over 22 lb (and less than 40 lb) are subject to testing with the Hybrid II 3-year-old (33 lb) dummy. Virtually all convertible restraints currently on the market are certified rear-facing for up to at least 30 lb, and often to 35 or 40 lb. The 3-year-old dummy therefore is more representative of children at the upper end of the recommended weight ranges for these restraints than the 18-month-old dummy.
The height recommendations would not change. The 850 mm height criterion was originally based on the 95th percentile 1-year-old and not the 9-month-old, so the substitution of the CRABI 12-month-old for the 9-month does not require a change.
Table 8: Dummy Selection Based on Height Recommendations
Recommended Height Range Dummy(ies) Currently Used in Compliance Testing Dummies Proposed for Use Not greater than 650 mm Newborn Newborn Greater than 650 mm but not greater than 850 mm Newborn, 9-month-old Newborn, CRABI Greater than 850 mm but not greater than 1100 mm 9-month-old, HII 3-year-old CRABI, HIII 3-year-old Greater than 1100 mm HII 6-year-old HIII 6-year-old
iii. Conditioning the Dummies
This document proposes detailed descriptions of the clothing, conditioning and positioning procedures for the dummies to ensure that the test conditions are carefully controlled.
Clothing for the 12-month-old CRABI and the Hybrid III 3- and 6-year-old dummies is currently specified in the corresponding sections of Part 572 that identify the design and performance criteria for each dummy. (Clothing is described in §572.154(c)(2) of Part 572 for the CRABI 12-month-old; in §572.144(c)(1) for the Hybrid III 3-year-old; and in §572.124(c)(2) for the Hybrid III 6-year-old.) It is proposed that the clothing specified in Part 572 for each dummy be used in the Standard No. 213 compliance test, except with respect to the identification of appropriate footwear. S9.1(c) of Standard No. 213 prescribes size 7M sneakers for the 3-year-old dummy and size 12 ½ M sneakers for the 6-year-old dummy with rubber toe caps, uppers of Dacron and cotton or nylon and a total mass of 0.453 kg. No such specifications are in Part 572. As such, we propose that S9.1(c) Standard No. 213 maintain the specification of footwear for the Hybrid III 3- and 6-year-old dummies. The clothing and footwear for the weighted 6-year-old dummy (see section V.d.2, infra) would be the same as that specified in Part 572 for the Hybrid III 6-year-old dummy.
The conditioning specifications specified in S9.3 of Standard No. 213 would be revised to reflect the same pre-test conditioning procedures that are currently specified in Standard No. 208 for the CRABI 12-month-old and the Hybrid III 3- and 6-year-old dummies. Namely, each dummy would be maintained at a temperature between 69 and 72 degrees F (between 20.6 and 22.2 degrees C) for at least 4 hours prior to a test. This would ensure that each dummy is conditioned in a manner that is consistent with the provisions specified in Part 572 for each dummy and its specific subassemblies. The dummy positioning requirements in S10 of Standard No. 213 would remain essentially unchanged. We note that S10.2.1(a) of Standard No. 213, which specifies rotating the legs of the 9-month-old dummy prior to placement of the dummy in a child restraint, is not needed for the CRABI 12-month-old dummy because of the spinal structure of the CRABI dummy.(11)
2. Using A Weighted 6-Year-Old Dummy
The second initiative relates to enhancing the dynamic evaluation of child restraints that are designed for older children. This NPRM proposes to use a weighted Hybrid III 6-year-old dummy to test child restraints that are recommended for use by children with masses up to 29.5 kg (65 lb).
A child reaching 40 lb (18 kg) has outgrown a convertible or toddler restraint, but still must be restrained by special means to safely ride in a vehicle. Parents tend to move these young children into the vehicle belt system, only to find that the lap and shoulder belts do not properly fit their children. The children are not yet large enough to sit with their backs against the vehicle seat back cushion with their knees bent over the seat edge. To compensate for a shoulder belt crossing their face or neck, some children tend to place the shoulder belt behind their backs, which results in no restraint of the child's upper torso. Children also find it more comfortable to bend their knees at the vehicle seat cushion's edge than to ride with the edge of the cushion pressing against their calves. Because their legs are not long enough to enable them to bend their knees at the cushion's edge while riding in a vehicle, children generally slouch down in the vehicle seat and scoot forward on the seat. Slouching raises the lap belt over their soft-tissue areas, which exposes abdominal organs to crash forces that can be imposed by the lap belt.
Klinich et al. estimates that children who are less than 148 centimeters in standing height do not adequately fit the seat belt and seating system in vehicles ("Study of Older Child Restraint/Booster Seat Fit and NASS Injury Analysis," DOT HS 808 248, November 1994.) Current NHTSA guidelines recommend booster seat use for children up to age 8, unless the child is 4' 9".
A booster seat improves the fit of a vehicle's belts on children. Booster seats are "child restraint systems" regulated in the same manner as other child restraint systems by Standard No. 213. The boosters come in a variety of styles, the majority having high-backs, with shoulder strap adjuster features on the sides. Belt-positioning seats (also referred to as "belt-positioning boosters") must be used with a lap and shoulder belt system. Boosters provide a raised seating platform for the child, which provides a taller sitting height. Raising the child helps position both the vehicle's lap and shoulder belts correctly. The seating platform also allows the child's knees to bend comfortably while the child is riding in the vehicle, which greatly reduces the tendency to slouch. Booster seats are dynamically tested by the agency using the 6-year- old test dummy, which weighs approximately 48 pounds and is about 48" tall.
In September 1996, the NTSB issued Safety Recommendation H-96-25, which asked NHTSA to revise Standard No. 213 to establish performance standards for booster seats that can restrain children up to 80 pounds. The Safety Board expressed concern about the performance of boosters when restraining a child that weighs more than the 6-year-old dummy that is currently used in Standard No. 213 compliance testing. This concern was also expressed by the Blue Ribbon Panel II in March 1999 ("Blue Ribbon Panel II: Protecting Our Older Child Passengers") in its report on ways to increase the use of age- and size-appropriate occupant restraints by children ages 4 through 15. Most booster seats currently on the market are certified for use by children weighing up to 80 lb. To better evaluate the performance of these boosters with children at the higher end of the weight range recommended for the restraint, the agency is pursuing two separate but parallel efforts to address the protection needs of older children. The first is a long- term program to develop a 76-lb, 10-year-old dummy. The second is a short-term initiative to use a weighted 6-year-old dummy to test booster seats beyond the 50-lb weight limit specified in FMVSS No. 213. The weighted dummy weighs 62 lb.
i. Development of the 10-Year-Old Dummy Is a Long-Term Measure
A 10-year-old dummy is being developed, but it is not far enough along in its development to be part of this NPRM. (12) The following summarizes the work on the dummy thus far.
In early 2000, NHTSA asked the Society of Automotive Engineers (SAE) Dummy Family Task Group (DFTG) to develop a test dummy representative of a 10-year-old child. The development and adoption of a dummy this size is seen as a long-term solution to ensuring the proper restraint of the approximately 10 percent of the population between the sizes of 6-year-olds and 5th percentile adult females, and could potentially be used in evaluating the performance of booster seats and vehicle belt systems. The group met initially in May 2000 to define the concept. The weight and height of the proposed dummy were provided from the Center for Disease Control Data Bank, and was targeted to be approximately 4'6" and 72 lb. The basic construction was envisioned to be similar to that of the small female dummy. The dummy was to be able to be positioned in erect seated, slouched seated, standing, and kneeling postures to fully evaluate possible restraint configurations.
The task group held its first review meeting in June 2000, and reviewed impact responses scaled from the small female and 6-year-old dummies. At that time, provisional performance requirements were defined, and the anthropometry and mass goals were finalized. The dummy instrumentation was specified to measure injury parameters for the following body regions: head, neck, shoulder, thorax, pelvis, femur, and tibia.
The first 10-year-old prototype was assembled in February 2001. It weighed about 76 lb. The task group reviewed this prototype, and directed design corrections. Subsequently, the first drawings were completed in April 2001. GM and NHTSA separately performed preliminary dummy performance verifications in Spring 2001 and Summer 2001, respectively. The agency is now conducting an extensive evaluation of the dummy, which will include a series of sled testing of the dummy. If no problems are encountered, NHTSA may issue an NPRM proposing the incorporation of the 10-year-old dummy into Part 572 by early 2003. When it issues such an NPRM, NHTSA will also undertake rulemaking on Standard No. 213 to propose using the dummy in compliance tests. At this time, we invite views on the development and potential use of the 10-year-old dummy in Standard No. 213's compliance tests.
ii. A Weighted 6-Year-Old Dummy Is a Feasible Short-Term Alternative
As a short-term, interim measure, NHTSA is proposing the use of a weighted Hybrid III 6-year-old dummy (hereinafter "HIII-6CW") for use in testing child restraints that are recommended for use by children weighing from 50 to 65 lb.
The agency developed the dummy by adding weights to the current Hybrid III 6- year-old child dummy to increase the total weight from approximately 52 pounds (13) to over 60 pounds. (14) NHTSA added approximately 10 pounds to the dummy so that it could be used to represent slightly heavier children. The initial design concept utilized carbon steel weights that were rigidly attached to the dummy in two locations: (1) a weight located on the superior side of the pelvis between the pelvis and the lumbar adaptor; and (2) weights located on the lateral sides of the thoracic spine box. The steel pelvis weight added 3.8 pounds to the dummy while the spine weights added a total of 5 pounds (each weight was 2.5 pounds on right and left sides). The resulting dummy weight was approximately 60 pounds. The modifications also increased the dummy's seating height by one inch. This change in stature appeared to be acceptable; a heavier occupant could also be slightly taller.
Following preliminary testing with the carbon steel weights and upon experiencing some belt retention problems, we determined that better weight and center of gravity distributions could be achieved through the use of a dense Tungsten alloy material. The geometry of the spine and pelvis weights was redesigned to achieve a weight of 5.1 pounds for the pelvis weight and 5.2 pounds total for the spine weights. The increased density offered by the Tungsten alloy allowed each of the weights to be reduced in size, thus reducing the possibility of interference between the ribs and the spine weights. Further, the dummy's seated height was only increased by approximately 0.7 inches over the unweighted HIII-6C dummy.
Preliminary evaluation tests have been conducted on dummies equipped with both the steel and Tungsten alloy versions of the weights. These tests included thoracic calibration impacts, torso flexion tests, and dynamic sled tests. The weights withstood dynamic impacts and testing without causing excessive noise or vibrations in the data channels. (Adding the weights does not require any permanent modifications to the dummy. When the weights are removed, the dummy reverts to its original condition and meets the existing Part 572 specifications for the Hybrid III unweighted 6-year-old dummy.)
Component tests conducted with the steel version indicate that the added weights did not appear to introduce structural or instrumentation problems. The thoracic responses met the calibration requirements of the unweighted HIII-6C dummy; however, the peak probe force measured during the compression interval was near the upper end of the corridor. Thus, the thoracic impact response corridor may need to be adjusted for the weighted dummy. Electronic responses and visual observations confirmed that there was no contact between the ribs and the spine weights during the oblique impacts. The torso flexion tests also met all of the requirements of the unweighted HIII-6C dummy.
Sled tests have been conducted with both the steel and Tungsten versions. For all sled tests, the current Standard No. 213 pulse and buck were used. Both versions of the dummy have been tested with different booster seats and with 3-point (lap and shoulder) belt systems. The results of the dummy, particularly with the high mass Tungsten weights, appear to be reasonable as compared to the standard HIII-6C dummy. That is, there have been no structural or electronic deficiencies observed as a result of the sled testing. Additionally, a series of four Standard No. 213 sled tests using various child restraints were performed to compare the response of the unweighted Hybrid III 6- year-old dummy to the HIII-6CW. Tests of the revised weighted 6-year-old H-III dummy produced normal dummy kinematics (motion in midsagittal plane) in booster seats and regular belt systems.
A technical report discussing the agency's work in developing the dummy, titled "Evaluation of the Weighted Hybrid III Six-Year-Old Dummy," has been placed in the docket. A proposal to incorporate the specifications and performance criteria for the HIII-6CW in Part 572 will be published in early 2002 in the FEDERAL REGISTER.
e. Expanding The Applicability Of The Standard to 65 Lb
NHTSA proposes to amend Standard No. 213 to increase the upper limits of its applicability so that it would apply to child restraint systems for children who weigh 65 lb or less. Currently, the standard defines "child restraint system" as "any device except Type I [lap] or Type II [lap/shoulder] seat belts, designed for use in a motor vehicle or aircraft to restrain, seat, or position children who weigh 50 pounds or less" (S4). We would amend the definition to increase the weight limit to 65 lb.
The effect of the amendment would be to apply Standard No. 213 to devices that are recommended for children weighing 50 to 65 lb. There has been considerable interest over the years in raising the limit to require that child restraint systems that are recommended for older children (i.e., booster seats) perform adequately in a crash. The aim of raising the limit was to bring booster seats that are recommended for children over 50 lb within Standard No. 213 and subject them to that standard's dynamic test, just as other restraints are tested under the standard. The intent to evaluate booster seat performance more thoroughly by dynamically testing them could not be realized, however, without a test dummy representing an older child. It would make little sense to raise the standard's limit above 50 lb if a test device were not available to test the performance of the restraint. Further, booster seats were not being marketed so as to be beyond the standard's purview; their recommended usage included children weighing less than 50 lb so they were, at least, subject to the 30 mph dynamic test with the 6-year-old (48 lb) dummy. For these reasons, NHTSA decided against increasing the 50 lb limit in the definition of "child restraint system." (See 58 FR 46928, 46932 for a discussion of the agency's decision not to undertake rulemaking on this issue.)
Today, we are proposing to incorporate a weighted 6-year-old dummy (62 lb total weight) into Part 572. We tentatively conclude that the dummy can provide useful information on the performance of booster seats that are recommended for children above 50 lb. Accordingly, we propose to increase the 50 lb weight limit in the definition of child restraint system to 65 lb. In the event that the weighted 6-year-old dummy is not determined to be sufficient for testing child restraints for children weighing above 50 lb, what would be the advantages and disadvantages of raising the limit nonetheless? Regardless of whether the weighted 6-year-old dummy were adopted, comments are also requested on the advantages and disadvantages of increasing the weight limit to eighty pounds (80 lb) in the absence of an 80-lb test device. Our tentative conclusion is that the weighted 6-year-old dummy is not sufficient to assess the dynamic performance of a booster seat in restraining an 80-lb child. Consumers Union (CU) has suggested in its comment to the agency's draft child passenger protection plan (Docket NHTSA-7938, page 11) that manufacturers should not be permitted to recommend a child restraint for children of weights above the weight of the largest test dummy used to evaluate the restraint in compliance testing. NHTSA previously declined the suggestion, believing that limiting the recommendations in the manner suggested could result in safety losses. (For example, a manufacturer would not be able to recommend a toddler restraint for children above the weight of the 3-year-old dummy, 33 lb, which would result in 3-year- olds being graduated out of child restraints at too early an age.) (61 FR 30824; June 18, 1996.) Comments are requested on CU's suggestion with respect to booster seats. If the weighted dummy were adopted, should manufacturers be allowed to recommend boosters for children only up to 62 lb?
f. New Or Revised Injury Criteria
This section describes proposed amendments to the measures that we use to assess the performance of child restraints under Standard No. 213. We propose injury criteria that are the same as the scaled injury criteria for children specified in Standard No. 208, Occupant Crash Protection. We also propose some requirements similar to the static testing requirements of Standard No. 213. The requirements that child restraints must maintain system integrity and limit excursion of the torso, head and knees in the simulated frontal impact would not be changed.
The agency requests comments on each of the proposed injury criteria. Comments are solicited on what risk levels are acceptable, what factors should be considered in selecting performance limits and whether the same limits as in Standard No. 208 should be established for the child restraint standard. The two standards address different sources of potential harm to children. The injury criteria for children in Standard No. 208 are intended to minimize the risk from a deploying air bag (ensuring that the air bag deploys in a manner much less likely to cause serious or fatal injury to out-of-position occupants). The injury criteria in Standard No. 213 are intended to limit the severity of forces imposed on a child during a crash. Child restraints meeting these criteria have worked effectively to maintain high levels of performance in crashes. Because the injury criteria of the standards are intended to minimize risks from different injury sources, it might be reasonable to have non-identical criteria.
1. Scaled Injury Criteria
The injury criteria that a child restraint must meet when restraining a dummy would change in several ways. Lower head and chest injury criteria are proposed, but the duration within which accelerations are measured would be limited. A new criterion for chest deflection is also proposed, as well as new criteria for neck injury. Currently, Standard No. 213 specifies a head injury criterion (HIC) of 1000 and maximum acceleration level for the chest (60g). These were based on the criteria that were specified for the adult male test dummy in Standard No. 208 in the early 1980's, when injury criteria were incorporated into Standard No. 213 (44 FR 72131; December 13, 1979). At that time, there were no injury criteria that were separately scaled from an adult dummy to reflect anatomical differences and differing injury tolerance of children. In the agency's May 2000 final rule on advanced air bag technology, NHTSA amended Standard No. 208 by, among other things, adjusting the criteria and performance limits to account for motor vehicle injury risks faced by different size occupants. (65 FR 30680; May 12, 2000.) See also a paper titled "Development of Improved Injury Criteria for the Assessment of Child Restraint Systems," that has been placed in the docket.
i. Head Injury
This NPRM proposes to replace the HIC 1000 limit in Standard No. 213 with the scaled HIC values adopted by the May 2000 air bag final rule: 700 for 6-year-old dummy, 570 for the 3-year-old dummy; and 390 for the CRABI 12-month-old. In Standard No. 208, these values are calculated over a 15 millisecond (msec) duration. We propose to calculate HIC over a 15 msec duration (HIC15) for Standard No. 213. Comments are requested on this issue, however, because while HIC15 is appropriate for Standard No. 208, there currently is no limit on the time duration used to calculate HIC in Standard No. 213. Generally speaking, limiting the time duration lowers the calculated HIC values.
A. Should HIC Duration Be Limited To 15 Milliseconds?
We have previously declined to limit the time duration for calculating HIC in Standard No. 213 compliance tests because of the possible lessening of the stringency of the standard. Prior to the May 2000 rule on advanced air bags, Standard No. 208 limited HIC to 1000 but limited the calculation to a maximum time interval of 36 msec (1000 36). In 1995, we were asked to amend Standard No. 213 to calculate HIC using a 36 msec time duration, as was done at the time for Standard No. 208. The agency decided against limiting HIC because we determined that HIC values were generally lower when the time interval was limited to 36 msec (HIC36), compared to HICunlimited (an unlimited time duration may be used to calculate HIC). Given that a HIC 36 limit could have reduced the stringency of the standard, there was not enough information justifying any limit on the time interval. Thus, NHTSA decided against limiting HIC to 36 msec in Standard No. 213. 69 FR 35127, July 6, 1995.
Now, however, we are considering limiting the time interval for measuring HIC in the child restraint standard. Standard No. 208 had provided for calculating HIC for the entire crash duration as the child restraint standard does now, but NHTSA limited the maximum time duration of the HIC calculation to 36 msec for Standard No. 208 because low acceleration crashes over a long time duration could exceed HIC 1000unlimited even though they were not likely to result in brain injuries. The agency determined that limiting the duration over which HIC is calculated to a maximum of 36 msec, while limiting HIC to 1000, assured that the acceleration level of the head will not exceed 60 g's for any period greater than 36 msec. The 60 g acceleration limit was set as a reasonable head injury threshold by the originators of the "Wayne State Tolerance Curve," which was used in the development of the HIC calculation. 51 FR 37028; October 17, 1986.
The time interval was further reduced to 15 msec by the May 2000 final rule amending Standard No. 208. The May 2000 rule on advanced air bags replaced 100036 with HIC 70015, based on recommendations from motor vehicle manufacturers that the duration for the HIC computations should be limited to 15 msec with a limit of 700 for the 50th percentile adult male dummy. NHTSA determined that the stringency of HIC 70015 was equivalent to HIC 100036 for long duration pulses, because while HIC15 produces a lower numerical value for long duration events, its 700 lower failure threshold compensated for the reduction. (15) The final rule employed a 15 msec time interval whenever calculating the HIC function in Standard No. 208, and limited the maximum response of the adult male dummy to 700 and the response of the smaller dummies to suitably scaled maximums (700 for the 6-year-old, 570 for the 3-year-old, and 390 for the CRABI).
Since the TREAD Act directs us to consider adopting the scaled injury criteria adopted by the May 2000 final rule on advanced air bags, we are proposing that the HIC limits of 70015, 57015 and 39015 be incorporated into Standard No. 213 for tests with the 6-year-old, the 3-year-old and the CRABI, respectively. NHTSA believes that it should take a cautious approach in modifying the head injury tolerance level set by the HIC requirement. Comments are requested on the appropriateness of both the scaled HIC limits and on a 15 msec (or other) time interval for calculating HIC. In cases of head contacts with softer surfaces, such as an airbag system, the time duration of the contact is longer than in head contacts with hard surfaces. Since HIC was initially developed for high acceleration, short duration impact events, it is appropriate to limit the HIC calculation in such airbag impacts, since the acceleration levels are low but time duration is long and not similar to the original intent of the HIC criterion. Data from sled testing of child restraints conducted at the agency's Vehicle Research & Test Center (VRTC) and from evaluating child restraints as part of the agency's New Car Assessment Program (NCAP) show that there was not a major difference between HICunlimited and HIC36, indicating that the HIC responses are from contact events shorter than 36 msec. Further, accident data show that 79 percent of all brain injuries for children 0-8 years old are due to contact, which would imply the prevalence of short duration head acceleration events. This finding appears to indicate a reasonable basis for making Standard No. 213's calculation of HIC consistent with Standard No. 208. Comments are requested on whether the time interval should be limited to 15 msec, to 36 msec, or not at all. Limiting the time interval to 15 msec would produce lower HIC values than the current method of calculating HIC in Standard No. 213, but the reduction in HIC100036 to the lower failure thresholds of 70015, 57015 and 39015 should achieve equivalent performance.
The agency does not know at this time the degree to which HIC 70015 and the scaled thresholds for the smaller dummies would reduce the current HIC failure rate of Standard No. 213 because data from past tests are unavailable in a format that allows us to recalculate the relevant values. However, based upon agency test results, we expect a high passage rate for HIC15. A series of five rear-facing and five forward-facing tests were conducted at VRTC with the CRABI dummy. In those tests, all five passed the HIC15390 requirement in the rear-facing tests. Three of five passed for the forward-facing tests. Forward facing tests with the Hybrid III 3- year-old dummy have indicated 100 percent passage of the HIC15570 requirement in Standard No. 213 conditions. A series of nine sled tests conducted under the NCAP program at an elevated sled test velocity of 35 mph also experienced a 100 percent passage of the requirement; a series of 20 in-vehicle crash tests with Hybrid III 3-year- old dummies conducted in NCAP produced over a 60 percent passage of the HIC15 requirement for these higher speed impact test conditions. For the 6-year-old Hybrid III dummy, the HIC15700 requirement was met 91 percent of the time in a series of 11 tests. Based upon these results, the agency has tentatively concluded that incorporation of the scaled HIC15 criteria for these Hybrid III child dummies would be reasonable. Comments on test result experience of vehicle and/or child restraint manufacturers with the Hybrid III child dummies and the scaled HIC15 responses are sought.
B. Test Data
The agency conducted two series of tests to evaluate if the child injury tolerance limits specified in FMVSS No. 208 are appropriate and practicable for use in testing child restraints using Hybrid III child dummies. The first series of sled tests was performed by VRTC to determine the performance of typical forward-facing child restraint systems secured by either a lap belt only, a lap and shoulder belt, or the LATCH system (the child restraint's attachments were attached to the child restraint by webbing material). The Hybrid III 3-year-old test dummy was used in this testing. The child restraint systems were installed and tested in either the rear seat of a contemporary sedan or the seating assembly specified in FMVSS No. 213. In addition, three sled acceleration pulses were studied: a typical Standard No. 208 frontal barrier crash (30 mph), an NCAP frontal crash (35 mph), and a Standard No. 213 pulse. The results of the VRTC sled testing are tabulated in Table 9 and discussed in a paper titled, "Dynamic Evaluation of Child Restraints Using Various Frontal Crash Pulses," which is available from the docket.
The second series of tests were performed in 20 NCAP vehicle crash tests to determine the performance of forward-facing child restraint systems restrained in the rear seat by a lap and shoulder belt with top tether and by a LATCH system (lower anchorages and top tether). The Hybrid III 3-year-old test dummy was also used in this testing. The results of these NCAP crash tests are tabulated and set forth in Table 10, infra.
Data from the VRTC sled tests and the NCAP full scale vehicle tests suggest that the new Standard No. 208 head injury criteria, HIC15, with its lower performance limit (570 for 3-year-old) is equivalent to the current HICunlimited with a performance limit of 1000. This conclusion is reached based upon the observation that both the Hybrid II HICunlimited and the Hybrid III HIC15 responses in Standard No. 213 appear to comply with their respective criteria limits with roughly a 50 percent margin.
ii. Thoracic Injury
A. Chest Acceleration
This document proposes new limits on chest acceleration and chest deflection. Currently, Standard No. 213 limits chest acceleration to 60 g's. The May 2000 final rule on advanced air bags scaled this value to 55 g's for the 3-year-old dummy and 50 g's for the CRABI. The chest acceleration limit remained at 60 g's for the 6-year-old dummy. We propose incorporating the same limits into Standard No. 213. For the 12-month-old CRABI dummy, the agency has observed chest accelerations of around 40 g's in rearward-facing child restraints. For forward-facing restraints using the 12-month-old CRABI dummy, nearly 75 percent of agency test results exceeded the 50 g limit, with accelerations generally less than 55 g's. Chest acceleration responses for both the 3- and 6-year-old dummies were well below their respective criteria in agency tests.
B. Chest Deflection
Currently, there is no chest deflection limit in Standard No. 213 because the current Hybrid II test dummies cannot measure chest deflection. Incorporating the Hybrid III 6- and 3-year-old dummies into Standard No. 213, as proposed in this NPRM, would enable us to measure deformation-deflection of the thorax sternum. Because the dummies would be capable of measuring this injury parameter, we propose that Standard No. 213 include limits on chest deflection.
The May 2000 final rule on advanced air bags reduced the deflection limit for the 50th percentile male dummy from 76 mm to 63 mm (from 3 inches (in) to 2.5 in). These limits were then scaled to obtain equivalent performance limits for the 6- and 3- year-old dummies. The CRABI does not measure chest deflection, so no limit was specified for that dummy. Compression deflection of the sternum relative to the spine was limited in Standard No. 208 to 40 mm (1.6 in) for the 6-year-old dummy and 34 mm (1.3 in) for the 3-year-old dummy.
We propose the same limits for Standard No. 213, except for the weighted 6-yar- old dummy (see next section, below). Comments are requested as to whether these limits are appropriate for testing child restraint systems, particularly with respect to webbing systems and impact shields that some child restraints use to restrain forward movement of the child's torso.
C. Weighted 6-Year-Old Dummy
Based upon scaling considerations of increased mass of the thoracic spine, greater chest compression limits appear to be justified for the HIII-6CW since this dummy would represent either an 8-year-old, or an 80th- to 90th- percentile 6-year-old in weight and stature.
In evaluating chest acceleration, a pure mathematical evaluation would indicate that accelerations should be somewhat lower for the heavier dummy. However, considering that both the 5th -percentile female and Hybrid III 6-year-old dummy have a 60g limit for injury assessment purposes, the agency is reluctant to propose a reduction to a lower g level for a dummy that is sized between the female and the existing 6-year-old.
Accordingly, the agency proposes to incorporate a 42 mm deflection limit for the weighted 6-year-old and a chest acceleration limit of 60 g.
D. Test Data
Data from the VRTC and NCAP tests indicate a high passing rate for chest acceleration and deflection tests. In the VRTC frontal sled tests, 94 percent of the tests of the LATCH seats (15 out of 16) resulted in passing values for chest acceleration (average 43 g's), and 100 percent (17 out of 17) passed chest deflection (average 0.61 in). For the non-LATCH seats, 76 percent (13 out of 17) passed chest acceleration (average 47 g's) and 100 percent (16 out of 16) passed chest deflection (average 0.73 in). These data suggest that the Standard No. 208 chest acceleration and chest deflection limits are practicable for child restraint systems.
iii. Neck Injury
Currently, there is no neck injury criterion in Standard No. 213, because the current Hybrid II test dummies are not designed with neck force measurement capability. However, the CRABI 12-month-old and the Hybrid III 3- and 6-year-old dummies have been designed to measure neck bending moments and forces in the fore and aft direction, and axial compression and tension loads. Because the dummies are capable of measuring neck injury parameters, we are proposing that the standard include a new neck criterion.
The May 2000 final rule on advanced air bags specified limits for a neck injury criterion, Nij, for the adult and child dummies used in Standard No. 208 compliance testing. Nij is a new injury formula that accounts for the combination of flexion, extension, tension and compression. Nij accounts for the superposition of loads and moments, and the additive effects on injury risk. Standard No. 208 includes an additional, more stringent tension/compression limit to independently control these potentially injurious loading modes in the air bag environment to out-of-position children.
This NPRM proposes to incorporate an Nij criterion in Standard No. 213 that is the same as that specified in Standard No. 208, except that the limit on peak tension and compression would not be adopted and the "in-position" critical values(16) would be used for calculation of the Nij. This decision is consistent with the agency's recognition of in-position critical values in the Standard No. 208 final rule, and with the observation that neck injury for children properly restrained in child restraints is not as prevalent as for those positioned in close proximity to an air bag at the time of deployment. A precise determination of neck injuries to children in child restraints has been difficult to quantify. When the NASS and FARS data are sorted to examine neck injury for children restrained in a child restraint and involved in a crash severity comparable to the Standard No. 213 sled pulse, few neck injuries are observed. However, biomechanics researchers have indicated to the agency that, although not frequent, such injuries do occur under severe crash conditions. In the agency's tests of child restraints, discussed below, the Nij values calculated when applying the in-position critical values ranged around Nij=1. NHTSA has tentatively determined that Standard No. 213 will incorporate the neck criterion of Nij = 1.0, where the critical values are the in- position values shown in Table 10, and the axial force is not limited. Comments are requested on this issue. NHTSA also requests comments on the need for any type of neck injury criterion at all in Standard No. 213, and the difficulty child restraint manufacturers may have in meeting this new injury measurement requirement.
Table 10: Nij In-Position Critical Values
|3 YO||2340 N
|6 YO||3096 N
iv. Tabulated Data
Table 9, supra, and the following table 11, set forth the data from the NCAP tests. They show that meeting the Nij is practicable, especially for LATCH seats, but that the neck measurements have little compliance margin for Nij = 1.0. A detailed discussion of the findings can be found in the technical paper, "Dynamic Evaluation of Child Restraints Using Various Frontal Crash Pulses," previously referenced in this preamble.
2. Static Testing Criteria
Certain changes to the requirements for which compliance is measured in a static test seem appropriate by an incorporation of the new test dummies.
Comments are requested on whether changes are needed to S5.2.3, which specifies a padding requirement for child restraints used by children weighing less than 22 lb. Should the requirement be deleted? NHTSA specified the requirement (whose thickness and static compression specifications are compliance-tested statically) because there was no instrumented infant test dummy available at the time (1979) the requirement was adopted. The agency's goal was to establish dynamic test requirements for infant restraints, so that the total energy absorption capability of the padding and underlying structure could be measured. (44 FR 72131, 72135). Since today's NPRM proposes use of the instrumented CRABI 12-month-old dummy for use in testing restraints recommended for children under 22 lb, we propose deleting S5.2.3.
The standard refers to use of one or more Hybrid II dummies in some of the static tests. These references would be changed to the Hybrid III dummies or the CRABI. See, e.g., S22.214.171.124, on use of the dummies to determine whether a seat back is required. See also S126.96.36.199(b) and S6.2.3 (post-impact buckle force release). NHTSA proposes to amend S6.2.3 so that the tension would be 90 N when a child restraint is tested with the CRABI, and 350 N when a child restraint is tested with the weighted 6-year-old dummy. Comments are requested as to what other requirements should be changed.
VI. Proposed Effective Dates
TREAD requires us to complete this rulemaking by November 1, 2002. Based on that date, the following section discusses tentative conclusions about the dates on which compliance with the requirements would become mandatory.
a. We believe that manufacturers could begin certifying their child restraints based on testing done on the new seat assembly by 2 years after the date of a final rule. That compliance date would be November 1, 2004. While we do not expect the proposed changes to the seat assembly to have a major effect on the results of compliance tests, restraint manufacturers will likely have to conduct testing to confirm compliance of their restraints. This will be a financial impact on the manufacturers that, coupled with the fact that some redesign may be necessary to meet the revised injury criteria (see next section), would be more appropriately spread out over a 2-year time period.
b. We propose providing 2 years of leadtime (two years after publication of a final rule) before specifying the use of the new CRABI and Hybrid III dummies in compliance tests and the revised or new injury criteria. That compliance date would be November 1, 2004. We believe that child restraint systems generally are already able to meet the proposed requirements using the new dummies, so redesign of current child restraints would not be generally needed. For some non-LATCH restraints, however, redesign might be needed to meet the new HIC15 and chest acceleration requirements, so longer leadtime might be needed. (As noted in section V(f), supra, some of the tested restraints failed to meet the proposed limits in the VRTC tests.) Comments are requested on how much leadtime would be necessary.
We also propose that manufacturers should be permitted the option of voluntarily using the new test dummies prior to the date on which they would be required to do so. Note, however, that this proposal also specifies that a manufacturer's selection of a compliance option (i.e., to use the new dummies prior to the mandatory compliance date) must be made prior to, or at the time of the compliance test and that the selection is irrevocable for that child restraint. This provision is needed for us to efficiently carry out our enforcement responsibilities. We want to avoid the situation of a manufacturer confronted with an apparent noncompliance (based on a compliance test) with the option it has selected responding to that noncompliance by arguing that its products comply with a different option for which the agency has not conducted a compliance test. To ensure that we will not be asked to conduct multiple compliance tests first for one compliance option, then for another, we would require manufacturers to select the option by the time it certifies the child restraint system and prohibit them from thereafter selecting a different option for the restraint. This would mean that failure to comply with the selected option would constitute a noncompliance regardless of whether the restraint complies with another option. (Of course, a manufacturer may petition for an exemption from the recall requirements of the statute on the basis that the noncompliance is inconsequential as it relates to motor vehicle safety.)
c. As for using the weighted 6-year-old dummy to test restraints (typically booster seats) recommended for children with masses of over 22.7 kg (weights over 50 lb), we propose that the dummy can begin to be used in compliance tests 180 days after publication of a final rule to incorporate the dummy into Part 572. The weighted dummy's kinematic performance is comparable to that of the unweighted 6-year-old dummy. We do not anticipate that manufacturers would have to redesign their booster seats to certify compliance using the dummy.
VII. Child Passenger Safety Plan and Other Issues of the TREAD Act
a. Comments on Possible Rulemaking
On November 27, 2000, the agency published a request for comments on a draft planning document that NHTSA prepared that outlined our vision for enhancing child passenger safety over the next few years (65 FR 70687). The plan contained our views on implementing three strategies for improving the safety of child occupants from birth through age 10: increasing restraint use; improving the performance and testing of child restraints; and improving mechanisms for providing safety information to the public. The agency received about 30 comments on the draft plan.
Many commenters responded to the second of the three strategies, making suggestions as to how they believed Standard No. 213 should be improved to further enhance child restraint performance. Based on the comments we received, we believe that this NPRM substantially addresses them. Commenters strongly supported the plan to update the standard seat assembly and evaluate the crash pulse specified in Standard No. 213 for compliance tests of child restraint systems. Commenters endorsed the plan to undertake rulemaking to add the CRABI and Hybrid III child test dummies to the standard, along with the scaled injury criteria. Commenters supported extending the scope of the standard to child restraint systems recommended for children above 50 lb. Additionally, the November 2, 2001 NPRM (66 FR 55623) addressed comments suggesting improvements to Standard No. 213's labeling requirements.
It should be noted that there were a few comments on amending Standard No. 213 to incorporate side impact protection requirements. These comments will be addressed in the forthcoming ANPRM.
b. Rear-Impact Test
No comments were received on incorporating rear impact test requirements into Standard No. 213.
As directed by the TREAD Act, we have considered whether to incorporate a rear impact test into the standard. During 1991-2000, 9,580 passenger vehicle occupants under 9 years old were fatally injured. Of these, 690 were killed in rear impact crashes (average of 69 per year), while 3751 and 2759 children were killed in front and side impact crashes, respectively. Of the 690 children killed in rear impact crashes in 1991-2000, 129 were restrained with a lap and/or shoulder belt; 218 were in child restraint systems; 280 were unrestrained and 63 were of other or unknown restraint use. Of the 69 children killed per year in rear impacts, on average 22 of them were in child restraint systems.
Data from the Fatal Analysis Reporting System (FARS) for 1991-2000 show 108 children, ages less than 1 year old, were fatally injured in rear impact crashes, while 655 children of that age group were killed in frontal crashes and 391 were killed in side crashes.
Based on these data and the timeframe of the TREAD Act, we have primarily focused on frontal and side impact protection. However, the agency intends to explore potential upgrades to Standard No. 213 in rear impact protection as part of the ANPRM.
c. Child Restraints in NCAP Tests
Section 14 (b)(9) of the TREAD Act requires consideration of "[w]hether to include child restraints in each vehicle crash tested under the New Car Assessment Program."
Each year since 1979, the agency has evaluated vehicle crashworthiness in frontal impact under the New Car Assessment Program (NCAP). In 1997, a side impact program was initiated and added to the NCAP. Under the NCAP, the agency conducts approximately 40 frontal and 40 side impact crash tests each year. For the frontal crash, the agency does these tests with two 50th percentile dummies in the front seat. Side impact crash tests are also conducted with a two 50th percentile dummies, however one dummy is placed in the driver seat and the other in the left rear passenger seat.
In response to the TREAD Act, NCAP incorporated various child restraints into frontal NCAP crash tests for the model year 2001 testing. Child restraints were placed in a total of twenty vehicles, varying in type and size. The agency evaluated performances of six different five-point-harness forward-facing child restraints. A fully instrumented Hybrid-III three-year-old dummy was used to assess performance. In each vehicle tested, the subject child restraint was secured tightly, as prescribed by the child restraint manufacturer's instructions. In addition, all child restraints, whether secured with LATCH or secured with a lap/shoulder belt, used a top tether. Similar testing will be conducted for both the front and side NCAP program in model year 2002.
Section 14(g) of the TREAD Act requires NHTSA to establish a child restraint safety rating consumer information program. NHTSA published a proposed rating program on November 6, 2001 (66 FR 56146, 66 FR 56048), which discussed the placement of child restraints in each vehicle crash tested under the New Car Assessment Program as a possible approach to obtain information for a rating program. We used the results of the child restraint NCAP tests in determining the feasibility of the proposal. The agency has asked for public comment on the rating program proposal and will consider the comments received, and all other available information, in deciding whether to include child restraints in vehicles tested under NCAP over the long-term.
VIII. Rulemaking Analyses and Notices
a. Executive Order 12866 (Regulatory Planning and Review) and DOT Regulatory Policies and Procedures
The agency has considered the impact of this rulemaking action under Executive Order 12866 and the Department of Transportation's regulatory policies and procedures and determined that it is "significant" because of Congressional and public interest in upgrading Standard No. 213 and the performance of child restraint systems. Accordingly, the action was reviewed under the Executive Order.
As discussed below and in NHTSA's preliminary regulatory evaluation (PRE) for this NPRM (17), the proposal to use new dummies in compliance tests, including a weighted 6-year-old dummy, could result in increased testing costs for manufacturers that want to certify their restraints using the tests that NHTSA will use in compliance testing. The PRE estimates that use of the new dummies and other aspects of the changes to the test procedure would add testing costs of $2.72 million. We believe that use of the new dummies, in itself, would not necessitate redesign of child restraints. The new dummies perform similarly to the ones presently used in compliance testing.
On the other hand, the new neck injury criteria would necessitate improvements in the performance of some child restraints. The agency estimates that the proposal to use the new and scaled injury criteria of Standard No. 208 would prevent an estimated 3-5 fatalities and 5 MAIS 2-5 non-fatal injuries for children ages 0-1 annually. In addition, the proposal would save 1 fatality and mitigate 1 MAIS 2-5 injury in the 4- to 6-year-old age group annually. These were estimated by evaluating the test results of some child restraints that failed the proposed neck injury criterion, and estimating what benefits would accrue if those restraints were redesigned so that they could just pass the proposed criterion. The needed design changes appear to be small, because the restraints that met or came close to meeting the proposed Nij limit appear outwardly to be the same as those that failed to meet it. Thus far, NHTSA has been unable to identify what changes manufacturers could make to enable their restraints to meet the proposed criterion. While meeting the proposed Nij limit appears feasible because test results for some current child restraints show that they met the proposed Nij value, we do not know which particular design features generally reduced Nij. Thus, we could not estimate the costs of such countermeasures. Comments are requested on possible countermeasures and their costs.
The agency does not believe that updating the seat assembly and revising the crash pulse would affect dummy performance to an extent that benefits would accrue from such changes. Research will be conducted later this year to assess the effects of such changes on dummy performance.
b. Regulatory Flexibility Act
The Regulatory Flexibility Act of 1980, as amended, requires agencies to evaluate the potential effects of their proposed and final rules on small businesses, small organizations and small governmental jurisdictions. I hereby certify that this NPRM would not have a significant economic impact on a substantial number of small entities. NHTSA estimates there to be about 10 manufacturers of child restraints, four or five of which could be small businesses. Manufacturers might have to make some design changes to some child restraints to meet the new injury criteria, particularly the neck injury criterion. NHTSA does not know the extent or nature of such changes, and has requested comments on them and their costs. We believe that only small changes to child restraints would be needed to allow them to pass the proposed neck injury criterion. Thus, there would likely be no impact on the number of child restraint producers. Comments are requested on the changes that are needed and the effect of this rule on the number of child restraint producers.
A rule adopting today's proposals would increase the testing that NHTSA conducts of child restraints, which in turn could increase the certification responsibilities of manufacturers. However, the agency does not believe such an increase would constitute a significant economic impact on small entities, because these businesses currently must certify their products to the dynamic test of Standard No. 213. That is, the products of these manufacturers already are subject to dynamic testing using child test dummies. The effect of this proposal on most child restraints is to subject them to testing with new dummies in place of existing ones. Testing child restraints on a new seat assembly is not expected to significantly affect the performance of the restraints.
c. Executive Order 13132 (Federalism)
Executive Order 13132 requires NHTSA to develop an accountable process to ensure "meaningful and timely input by State and local officials in the development of regulatory policies that have federalism implications." "Policies that have federalism implications" is defined in the Executive Order to include regulations that have "substantial direct effects on the States, on the relationship between the national government and the States, or on the distribution of power and responsibilities among the various levels of government." Under Executive Order 13132, the agency may not issue a regulation with Federalism implications, that imposes substantial direct compliance costs, and that is not required by statute, unless the Federal government provides the funds necessary to pay the direct compliance costs incurred by State and local governments, the agency consults with State and local governments, or the agency consults with State and local officials early in the process of developing the proposed regulation. NHTSA also may not issue a regulation with Federalism implications and that preempts State law unless the agency consults with State and local officials early in the process of developing the proposed regulation.
We have analyzed this proposed rule in accordance with the principles and criteria set forth in Executive Order 13132 and have determined that this proposal does not have sufficient Federal implications to warrant consultation with State and local officials or the preparation of a Federalism summary impact statement. The proposal would not have any substantial impact on the States, or on the current Federal-State relationship, or on the current distribution of power and responsibilities among the various local officials.
d. Unfunded Mandates Reform Act
Section 202 of the Unfunded Mandates Reform Act of 1995 (UMRA) requires Federal agencies to prepare a written assessment of the costs, benefits and other effects of proposed or final rules that include a Federal mandate likely to result in the expenditure by State, local or tribal governments, in the aggregate, or by the private sector, of more than $100 million in any one year ($100 million adjusted annually for inflation, with base year of 1995). (Adjusting this amount by the implicit gross domestic product price deflator for the year 2000 results in $109 million.) This NPRM will not result in costs of $109 million or more to either State, local, or tribal governments, in the aggregate, or to the private sector. Thus, this NPRM is not subject to the requirements of sections 202 of the UMRA.
e. National Environmental Policy Act
NHTSA has analyzed this proposal for the purposes of the National Environmental Policy Act. The agency has determined that implementation of this action would not have any significant impact on the quality of the human environment.
f. Executive Order 12778 (Civil Justice Reform)
This proposal would not have any retroactive effect. Under 49 U.S.C. 21403, whenever a Federal motor vehicle safety standard is in effect, a State may not adopt or maintain a safety standard applicable to the same aspect of performance which is not identical to the Federal standard, except to the extent that the state requirement imposes a higher level of performance and applies only to vehicles procured for the State's use. 49 U.S.C. 21461 sets forth a procedure for judicial review of final rules establishing, amending or revoking Federal motor vehicle safety standards. That section does not require submission of a petition for reconsideration or other administrative proceedings before parties may file suit in court.
g. Plain Language
Executive Order 12866 requires each agency to write all rules in plain language. Application of the principles of plain language includes consideration of the following questions:
If you have any responses to these questions, please include them in your comments on this proposal.
h. Paperwork Reduction Act
Under the Paperwork Reduction Act of 1995, a person is not required to respond to a collection of information by a Federal agency unless the collection displays a valid OMB control number. This proposed rule does not contain any collection of information requirements requiring review under the Paperwork Reduction Act.
i. National Technology Transfer and Advancement Act
Section 12(d) of the National Technology Transfer and Advancement Act of 1995 (NTTAA) directs us to use voluntary consensus standards in our regulatory activities unless doing so would be inconsistent with applicable law or otherwise impractical. Voluntary consensus standards are technical standards (e.g., materials specifications, test methods, sampling procedures, and business practices) that are developed or adopted by voluntary consensus standards bodies, such as the International Organization for Standardization (ISO). The NTTAA directs us to provide Congress, through OMB, explanations when we decide not to use available and applicable voluntary consensus standards.
There are no voluntary consensus standards available for use at this time.
IX. Submission of Comments
How Can I Influence NHTSA's Thinking on This Proposed Rule?
In developing this proposal, we tried to address the concerns of all our stakeholders. Your comments will help us improve this proposed rule. We invite you to provide different views on options we propose, new approaches we haven't considered, new data, how this proposed rule may affect you, or other relevant information. We welcome your views on all aspects of this proposed rule, but request comments on specific issues throughout this document. Your comments will be most effective if you follow the suggestions below:
How Do I Prepare and Submit Comments?
Your comments must be written and in English. To ensure that your comments are correctly filed in the Docket, please include the docket number of this document in your comments.
Your comments must not be more than 15 pages long (49 CFR §553.21). We established this limit to encourage you to write your primary comments in a concise fashion. However, you may attach necessary additional documents to your comments. There is no limit on the length of the attachments.
Please submit two copies of your comments, including the attachments, to Docket Management at the address given above under ADDRESSES.
Comments may also be submitted to the docket electronically by logging onto the Dockets Management System website at Click on "Help & Information" or "Help/Info" to obtain instructions for filing the document electronically.
How Can I Be Sure That My Comments Were Received?
If you wish Docket Management to notify you upon its receipt of your comments, enclose a self-addressed, stamped postcard in the envelope containing your comments. Upon receiving your comments, Docket Management will return the postcard by mail.
How Do I Submit Confidential Business Information?
If you wish to submit any information under a claim of confidentiality, you should submit three copies of your complete submission, including the information you claim to be confidential business information, to the Chief Counsel, NHTSA, at the address given above under FOR FURTHER INFORMATION CONTACT. In addition, you should submit two copies, from which you have deleted the claimed confidential business information, to Docket Management at the address given above under ADDRESSES. When you send a comment containing information claimed to be confidential business information, you should include a cover letter setting forth the information specified in our confidential business information regulation. (49 CFR Part 512.)
Will the Agency Consider Late Comments?
We will consider all comments that Docket Management receives before the close of business on the comment closing date indicated above under DATES. To the extent possible, we will also consider comments that Docket Management receives after that date. If Docket Management receives a comment too late for us to consider it in developing a final rule (assuming that one is issued), we will consider that comment as an informal suggestion for future rulemaking action.
How Can I Read the Comments Submitted by Other People?
You may read the comments received by Docket Management at the address given above under ADDRESSES. The hours of the Docket are indicated above in the same location.
You may also see the comments on the Internet. To read the comments on the Internet, take the following steps:
(1) Go to the Docket Management System (DMS) Web page of the Department of Transportation (http://dms.dot.gov/).
(2) On that page, click on "search."
(3) On the next page (http://dms.dot.gov/search/), type in the four-digit docket number shown at the beginning of this document. Example: If the docket number were "NHTSA-2002-1234," you would type "1234." After typing the docket number, click on "search."
(4) On the next page, which contains docket summary information for the docket you selected, click on the desired comments. You may download the comments. However, since the comments are imaged documents, instead of word processing documents, the downloaded comments are not word searchable.
Please note that even after the comment closing date, we will continue to file relevant information in the Docket as it becomes available. Further, some people may submit late comments. Accordingly, we recommend that you periodically check the Docket for new material. Upon receiving the comments, the docket supervisor will return the postcard by mail.
List of Subjects in 49 CFR Part 571
Motor vehicle safety, Reporting and recordkeeping requirements, Tires.
PART 571 - [Amended]
In consideration of the foregoing, NHTSA proposes to amend 49 CFR Part 571 as set forth below.
Authority: 49 U.S.C. 322, 30111, 30115, 30117 and 30166; delegation of authority at 49 CFR 1.50.
The revised and added text and figure would read as follows:
§571.213 Standard No. 213, Child restraint systems.
* * * * *
Child restraint system means any device, except Type I or Type II seat belts, designed for use in a motor vehicle or aircraft to restrain, seat, or position children who weigh 65 pounds or less.
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S5.1.2 Injury criteria. When tested in accordance with S6.1 and with the test dummies specified in S7, each child restraint system manufactured before November 1, 2004, shall--
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S188.8.131.52 When tested in accordance with S6.1 and with the test dummies specified in S7, each child restraint system manufactured on or after November 1, 2004, shall--
(a) Limit the resultant acceleration at the location of the accelerometer mounted in the test dummy head such that, for any two points in time, t1 and t2 , during the event which are separated by not more than a 15 millisecond time interval and where t1 is less than t2, the maximum calculated head injury criterion (HIC15) shall not exceed the limits specified in the table in this S184.108.40.206, determined using the resultant head acceleration at the center of gravity of the dummy head, ar, expressed as a multiple of g (the acceleration of gravity), calculated using the expression:
(b) The resultant acceleration calculated from the output of the thoracic instrumentation shall not exceed the limits specified in the table in this S220.127.116.11, except for intervals whose cumulative duration is not more than 3 milliseconds.
(c) Compression deflection of the sternum relative to the spine, as determined by instrumentation, shall not exceed the limits specified in the table in this S18.104.22.168.
Table to S22.214.171.124(a)-(c): Injury Limits for Head and Thorax
Test Dummy Maximum Calculated
Maximum Thoracic G's (S126.96.36.199(b)) Maximum Chest Deflection (S188.8.131.52(c)) 12-Month-Old Subpart R 390 50 g's N/A 3-Year-Old Subpart P 570 55 g's 34 mm (1.3 in) 6-Year-Old Subpart N 700 60 g's 40 mm (1.6 in) Weighted 6-Year-Old 700 60 g's 42 mm (1.65 in)
(d) Neck injury. For the measurement of neck injury, the following injury criteria shall be met when calculated based on data recorded for the first 300 milliseconds of the sled pulse.
(1) The shear force (Fx), axial force (Fz), and bending moment (My) shall be measured by the dummy upper neck load cell for 300 milliseconds, as specified in S184.108.40.206(d). Shear force, axial force, and bending moment shall be filtered for Nij purposes at SAE J211/1 rev. Mar95 Channel Frequency Class 600 (see 49 CFR §571.208, S4.7).
(2) During the event, the axial force (Fz) can be either in tension or extension, the occipital condyle bending moment (Mocy) can be in either flexion or extension. This results in four possible loading conditions for Nij: tension-extension (Nte), tension-flexion (Ntf), compression-extension (Nce), or compression-flexion (Ncf). For the calculation of Nij using the equation set forth in S220.127.116.11(d)(3), the critical values, Fzc and Myc, are as specified in the table to this S18.104.22.168(d) for each of the dummies used in the test.
(3) At each point in time, only one of the four loading conditions occurs. The Nij value corresponding to that loading condition is computed and the three remaining loading modes shall be considered to have a value of zero. The equation for calculating each Nij loading condition is given by:
Nij = (Fz/Fzc) + (Mocy/Myc)
(4) None of the four Nij values shall exceed 1.0 at any time during the event.
Table to S22.214.171.124(d)--Critical Values for Calculating Nij
|Test Dummy||Fzc when Fz is in tension||Fzc when Fz is in compression||Myc when a flexion moment exists at the occipital condyle||Myc when an extension moment exists at the occipital condyle|
|12-Month-Old Subpart R||1460 N
|3-Year-Old||2340 N||2120 N||68 Nm||30 Nm|
|6-Year-Old Subpart N||3096 N
|Weighted 6-Year-Old||3096 N
S126.96.36.199 At the manufacturer's option (with said option irrevocably selected prior to, or at the time of, certification of the restraint), child restraint systems manufactured before November 1, 2004 may be tested to the requirements of S5 while using the test dummies specified in S7.1.2 of this standard according to the criteria for selecting test dummies specified in that paragraph. That paragraph specifies the dummies used to test child restraint systems manufactured on or after November 1, 2004. If a manufacturer selects the dummies specified in S7.1.2 to test its product, the injury criteria specified by S188.8.131.52 of this standard must be met. Child restraints manufactured on or after November 1, 2004, must be tested using the test dummies specified in S7.1.2.
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S5.2 Force distribution.
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S184.108.40.206 The applicability of the requirements of S220.127.116.11 to a front-facing child restraint, and the conformance of any child restraint other than a car bed to those requirements, is determined using the largest of the test dummies specified in S7 for use in testing that restraint, provided that the 6-year-old dummy described in subpart I or in subpart N of part 572 of this title is not used to determine the applicability of or compliance with S18.104.22.168. A front-facing child restraint system is not required to comply with S22.214.171.124 if the target point on either side of the dummy's head is below a horizontal plane tangent to the top of--
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S6.1.1 Test conditions.
(a) Test devices.
(1) The test device for testing add-on restraint systems to frontal barrier impact simulations is a standard seat assembly consisting of a simulated vehicle bench seat, with three seating positions, which is described in Drawing Package SAS-100-1000 with Addendum __: Seat Base Weldment (consisting of drawings and a bill of materials), dated ______ (will be incorporated by reference in §571.5). The assembly is mounted on a dynamic test platform so that the center SORL of the seat is parallel to the direction of the test platform travel and so that movement between the base of the assembly and the platform is prevented.
* * * * *
(d)(1) When using the test dummies specified in 49 CFR Part 572, subparts C, I, J, or K, performance tests under S6.1 are conducted at any ambient temperature from 19º C to 26º C and at any relative humidity from 10 percent to 70 percent.
(2) When using the test dummies specified in 49 CFR Part 572, subparts N, P or R, performance tests under S6.1 are conducted at any ambient temperature from 20.6º C to 22.2º C and at any relative humidity from 10 percent to 70 percent.
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S6.2.3 Pull the sling tied to the dummy restrained in the child restraint system and apply the following force: 50 N for a system tested with a newborn dummy; 90 N for a system tested with a 9-month-old dummy; 90 N for a system tested with a 12-month-old dummy; 200 N for a system tested with a 3-year-old dummy; 270 N for a system tested with a 6-year-old dummy; or 350 N for a system tested with a weighted 6-year-old dummy. The force is applied in the manner illustrated in Figure 4 and as follows:
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S7 Test dummies. (Subparts referenced in this section are of part 572 of this chapter.)
S7.1 Dummy selection. Select any dummy specified in S7.1.1, S7.1.2 or S7.1.3, as appropriate, for testing systems for use by children of the height and mass for which the system is recommended in accordance with S5.5. A child restraint that meets the criteria in two or more of the following paragraphs in S7 may be tested with any of the test dummies specified in those paragraphs.
S7.1.1 Child restraints that are manufactured before November 1, 2004, are subject to the following provisions.
(a) A child restraint that is recommended by its manufacturer in accordance with S5.5 for use either by children in a specified mass range that includes any children having a mass of not greater than 5 kg, or by children in a specified height range that includes any children whose height is not greater than 650 mm, is tested with a newborn test dummy conforming to part 572 subpart K.
(b) A child restraint that is recommended by its manufacturer in accordance with S5.5 for use either by children in a specified mass range that includes any children having a mass greater than 5 but not greater than 10 kg, or by children in a specified height range that includes any children whose height is greater than 650 mm but not greater than 850 mm, is tested with a newborn test dummy conforming to part 572 subpart K, and a 9-month-old test dummy conforming to part 572 subpart J.
(c) A child restraint that is recommended by its manufacturer in accordance with S5.5 for use either by children in a specified mass range that includes any children having a mass greater than 10 kg but not greater than 18 kg, or by children in a specified height range that includes any children whose height is greater than 850 mm but not greater than 1100 mm, is tested with a 9-month-old test dummy conforming to part 572 subpart J, and a 3-year-old test dummy conforming to part 572 subpart C and S7.2, provided, however, that the 9-month-old dummy is not used to test a booster seat.
(d) A child restraint that is recommended by its manufacturer in accordance with S5.5 for use either by children in a specified mass range that includes any children having a mass greater than 18 kg, or by children in a specified height range that includes any children whose height is greater than 1100 mm, is tested with a 6-year-old child dummy conforming to part 572 subpart I.
(e) A child restraint that is manufactured on or after [date to be inserted would be the date 180 days after publication of a final rule incorporating a weighted 6-year-old dummy into Part 572], and that is recommended by its manufacturer in accordance with S5.5 for use either by children in a specified mass range that includes any children having a mass greater than 22.7 kg (50 lb), or by children in a specified height range that includes any children whose height is greater than 1100 mm, is tested with a weighted 6-year-old child dummy conforming to Part 572 Subpart [to be determined].
S7.1.2 Child restraints that are manufactured on or after November 1, 2004, are subject to the following provisions.
(a) A child restraint that is recommended by its manufacturer in accordance with S5.5 for use either by children in a specified mass range that includes any children having a mass of not greater than 5 kg, or by children in a specified height range that includes any children whose height is not greater than 650 mm, is tested with a newborn test dummy conforming to part 572 subpart K.
(b) A child restraint that is recommended by its manufacturer in accordance with S5.5 for use either by children in a specified mass range that includes any children having a mass greater than 5 but not greater than 10 kg, or by children in a specified height range that includes any children whose height is greater than 650 mm but not greater than 850 mm, is tested with a newborn test dummy conforming to part 572 subpart K, and a 12-month-old test dummy conforming to part 572 subpart R.
(c) A child restraint that is recommended by its manufacturer in accordance with S5.5 for use either by children in a specified mass range that includes any children having a mass greater than 10 kg but not greater than 18 kg, or by children in a specified height range that includes any children whose height is greater than 850 mm but not greater than 1100 mm, is tested with a 12-month-old test dummy conforming to part 572 subpart R, and a 3-year-old test dummy conforming to part 572 subpart P and S7.2, provided, however, that the 12-month-old dummy is not used to test a booster seat.
(d) A child restraint that is recommended by its manufacturer in accordance with S5.5 for use either by children in a specified mass range that includes any children having a mass greater than 18 kg, or by children in a specified height range that includes any children whose height is greater than 1100 mm, is tested with a 6-year-old child dummy conforming to part 572 subpart N.
(e) A child restraint that is manufactured on or after [date to be inserted would be the date 180 days after publication of a final rule incorporating a weighted 6-year-old dummy into Part 572], and that is recommended by its manufacturer in accordance with S5.5 for use either by children in a specified mass range that includes any children having a mass greater than 22.7 kg (50 lb), or by children in a specified height range that includes any children whose height is greater than 1100 mm, is tested with a weighted 6-year-old child dummy conforming to Part 572 Subpart [to be determined].
S7.1.3 Voluntary use of alternative dummies. At the manufacturer's option (with said option irrevocably selected prior to, or at the time of, certification of the restraint), child restraint systems manufactured before November 1, 2004 may be tested to the requirements of S5 while using the test dummies specified in S7.1.2 according to the criteria for selecting test dummies specified in that paragraph. Child restraints manufactured on or after November 1, 2004, must be tested using the test dummies specified in S7.1.2.
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S9.1 Type of clothing.
* * *
(c) 12-month-old dummy (49 CFR Part 572, Subpart R). When used in testing under this standard, the dummy specified in 49 CFR Part 572, Subparts R, is clothed in a cotton-polyester based tight fitting swear shirt with long sleeves and ankle long pants whose combined weight is not more than 0.25 kg (.55 lb).
(d) Hybrid II three-year-old and Hybrid II six-year-old dummies (49 CFR Part 572, Subparts C and I). When used in testing under this standard, the dummies specified in 49 CFR Part 572, Subparts C and I, are clothed in thermal knit, waffle-weave polyester and cotton underwear or equivalent, a size 4 long-sleeved shirt (3-year-old dummy) or a size 5 long-sleeved shirt (6-year-old dummy) having a mass of 0.090 kg, a size 4 pair of long pants having a mass of 0.090 kg, and cut off just far enough above the knee to allow the knee target to be visible, and size 7M sneakers (3-year-old dummy) or size 12 1/2M sneakers (6-year-old dummy) with rubber toe caps, uppers of dacron and cotton or nylon and a total mass of 0.453 kg.
(e) Hybrid III 3-year-old dummy (49 CFR Part 572, Subpart P). When used in testing under this standard, the dummy specified in 49 CFR Part 572, Subpart P, is clothed in a cotton-polyester based tight fitting swear shirt with long sleeves and ankle long pants whose combined weight is not more than 0.25 kg (.55 lb), and size 7M sneakers with rubber toe caps, uppers of dacron and cotton or nylon and a total mass of 0.453 kg.
(f) Hybrid III 6-year-old dummy (49 CFR Part 572, Subpart N) and Hybrid III weighted 6-year-old dummy (40 CFR Part 572, Subpart _). When used in testing under this standard, the dummy specified in 49 CFR Part 572, Subpart N, and in Subpart [to be determined], is clothed in a light-weight cotton stretch short-sleeve shirt and above-the-knee pants, and size 12.5M sneakers with rubber toe caps, uppers of dacron and cotton or nylon and a total mass of 0.453 kg.
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S9.3 Preparing dummies. (Subparts referenced in this section are of Part 572 of this chapter.)
S9.3.1 When using the test dummies conforming to Part 572 Subparts C, I, J, or K, prepare the dummies as specified in this paragraph. Before being used in testing under this standard, dummies must be conditioned at any ambient temperature from 19C to 25.5C and at any relative humidity from 10 percent to 70 percent, for at least 4 hours.
S9.3.2 When using the test dummies conforming to Part 572 Subparts N, P, R, or [subpart on the weighted 6-year-old dummy to be inserted], prepare the dummies as specified in this paragraph. Before being used in testing under this standard, dummies must be conditioned at any ambient temperature from 20.6 to 22.2 C (69 to 72 F) and at any relative humidity from 10 percent to 70 percent, for at least 4 hours.
* * * * *
S10.2.1 * * *
(b) * * *
(2) When testing rear-facing child restraint systems, place the newborn, 9-month-old or 12-month-old dummy in the child restraint system so that the back of the dummy torso contacts the back support surface of the system. For a child restraint system which is equipped with a fixed or movable surface described in S126.96.36.199 which is being tested under the conditions of test configuration II, do not attach any of the child restraint belts unless they are an integral part of the fixed or movable surface. For all other child restraint systems and for a child restraint system with a fixed or movable surface which is being tested under the conditions of test configuration I, attach all appropriate child restraint belts and tighten them as specified in S6.1.2. Attach all appropriate vehicle belts and tighten them as specified in S6.1.2. Position each movable surface in accordance with the instructions that the manufacturer provided under S5.6.1 or S5.6.2. If the dummy's head does not remain in the proper position, tape it against the front of the seat back surface of the system by means of a single thickness of 6 mm-wide paper masking tape placed across the center of the dummy's face.
(c)(1)(i) When testing forward-facing child restraint systems, extend the arms of the 9-month-old or 12-month-old test dummy as far as possible in the upward vertical direction. Extend the legs of the 9-month-old or 12-month-old test dummy as far as possible in the forward horizontal direction, with the dummy feet perpendicular to the centerline of the lower legs. Using a flat square surface with an area of 2,580 square mm, apply a force of 178 N, perpendicular to:
* * * * *
(B) The back of the vehicle seat in the specific vehicle shell or the specific vehicle, in the case of a built-in system, first against the dummy crotch and then at the dummy thorax in the midsagittal plane of the dummy. For a child restraint system with a fixed or movable surface described in S188.8.131.52, which is being tested under the conditions of test configuration II, do not attach any of the child restraint belts unless they are an integral part of the fixed or movable surface. For all other child restraint systems and for a child restraint system with a fixed or movable surface that is being tested under the conditions of test configuration I, attach all appropriate child restraint belts and tighten them as specified in S6.1.2. Attach all appropriate vehicle belts and tighten them as specified in S6.1.2. Position each movable surface in accordance with the instructions that the manufacturer provided under S5.6.1 or S5.6.2.
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(2) When testing rear-facing child restraint systems, extend the dummy's arms vertically upwards and then rotate each arm downward toward the dummy's lower body until the arm contacts a surface of the child restraint system or the standard seat assembly in the case of an add-on child restraint system, or the specific vehicle shell or the specific vehicle, in the case of a built-in child restraint system. Ensure that no arm is restrained from movement in other than the downward direction, by any part of the system or the belts used to anchor the system to the standard seat assembly, the specific shell, or the specific vehicle.
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S10.2.2 * * *
(c) * * *
(2) The back of the vehicle seat in the specific vehicle shell or the specific vehicle, in the case of a built-in system, first against the dummy crotch and then at the dummy thorax in the midsagittal plane of the dummy. For a child restraint system with a fixed or movable surface described in S184.108.40.206, which is being tested under the conditions of test configuration II, do not attach any of the child restraint belts unless the belt is an integral part of the fixed or movable surface. For all other child restraint systems and for a child restraint system with a fixed or movable surface that is being tested under the conditions of test configuration I, attach all appropriate child restraint belts and tighten them as specified in S6.1.2. Attach all appropriate vehicle belts and tighten them as specified in S6.1.2. Position each movable surface in accordance with the instructions that the manufacturer provided under S5.6.1 or S5.6.2.
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Stephen R. Kratzke
Associate Administrator for Safety Performance Standards
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Billing Code: 4910-59-P
[Signature page for NPRM Child Restraint Systems, RIN 2127-AI34]
1. Standard No. 213 currently requires booster seats to be dynamically tested in 3-point (lap and shoulder) belts. As such, the agency is taking no action with respect to this provision of the TREAD Act. [Footnote added.]
2. In addition, Section 14 of the TREAD Act required an NPRM to establish a child restraint safety rating consumer information program to provide consumers information for use in the purchase of child restraints. The NPRM was issued on October 29, 2001, and published November 6, 2001 (66 FR 56146, 66 FR 56048). Further, on October 29, 2001, the agency issued an NPRM on Standard No. 213's labeling and owner's manual requirements that responds to Section 14(b)(5) of the Act. 66 FR 55623, November 2, 2001. The Act also required a study on the use and effectiveness of booster seats and a 5-year strategic plan to reduce, by 25 percent, deaths and injuries caused by failure to use the appropriate booster seat in the 4- to 8-year-old age group.
3. Standard No. 225 requires motor vehicle manufacturers to provide vehicles equipped with the child restraint anchorage systems that are standardized and independent of the vehicle seat belts. The new independent system has two lower anchorages, and one upper anchorage. Each lower anchorage includes a rigid round rod or "bar" unto which a hook, a jaw-like buckle or other connector can be snapped. The bars are located at the intersection of the vehicle seat cushion and seat back. The upper anchorage is a ring-like object to which the upper tether of a child restraint system can be attached. (The system is widely known as the "LATCH system," an acronym developed by manufacturers and retailers for "lower anchors and tether for children.") The LATCH system is required to be installed at two rear seating positions. In addition, a tether anchorage is required at a third position. By requiring an easy-to- use anchorage system that is independent of the vehicle seat belts, NHTSA's standard makes possible more effective child restraint installation and thereby increases child restraint effectiveness and child safety. The standard is estimated to save 36 to 50 lives annually, and prevent 1,231 to 2,929 injuries. See 64 FR 10786; March 5, 1999.
4. The petition is granted to the extent it is consistent with today's NPRM. However, granting of the petition does not mean that the changes requested will be adopted. Granting of the petition indicates that the agency believes that the recommended change has merit and warrants further review and evaluation. A decision whether to adopt the recommended change will be made on the basis of all available information developed in the course of the rulemaking proceeding, in accordance with statutory criteria.
5. Hiltner, Edward C. and MacLaughlin, Thomas F., "Child Seating Test Procedure Development," NHTSA Final Report No. DOT HS 807 466, March 1989.
6. Our laboratory test procedure (TP) for Standard 213 (TP-213-04, September 1, 1997), specifies a "tolerance band," or "acceleration function envelope," that incorporates the upper limit of Figure 2 and that also sets a lower limit (see section D.3.3, "Impact Severity" (page 53)).
7. FMVSS No. 213's pulse is quite different than any other pulse used to regulate child restraints. The Europeans, the Canadians and the Australians all use different crash pulses to test their child restraints. The FMVSS No. 213 pulse seems to be more severe than the other pulses because of its sharp rise time and the short duration of the crash pulse. Of these three international pulses, the only similarity between the three was the time duration. All other pulses used to regulate child restraints, except FMVSS No. 213, ended beyond 100 msec. The U.S. has about 10 times the LTV sales as Europe (50 percent versus 5 percent). In Australia, LTV sales constitute about 25 percent of the total vehicles sold in that country.
8. A more severe crash pulse is defined as one having a higher acceleration onset rate, higher peak acceleration, and/or a shorter time duration.
9. Britax Child Safety Inc. submitted a petition for rulemaking on September 22, 2000, to allow manufacturers to specify use of the CRABI in compliance testing in place of the 9-month-old dummy. To the extent the petition is consistent with this NPRM, it is granted.
10. A convertible child restraint can be used rear- facing with infants and young toddlers, and forward-facing with older toddlers. They typically are recommended for use by children from birth until the child reaches 40 lb.
11. The proposed regulatory text of this NPRM retains the specifications in Standard No. 213 for conditioning and positioning the 9-month-old dummy and the Hybrid II dummies because the dummies would continue to be used in compliance tests until the mandatory compliance date of a final rule (which is proposed to be November 1, 2004).
12. The legislative history to TREAD indicates that Congress was interested in the potential for using the 10-year-old dummy specified in ECE 44. That dummy is manufactured by the Netherlands Organisation for Applied Scientific Research (TNO), which manufactures the other test dummies referenced in ECE 44. These dummies are TNO's "P" series of child dummies, which includes a newborn, a 9-month, 18- month, and 3-, 6-, and 10-year-old. All P series dummies are of similar construction. The agency evaluated the 3-year-old child dummy and found it to have insurmountable seating stability problems when placed in a child restraint, and un-human-like impact kinematics because of its cervical and thoracic spine construction. We also found problems with the instrumentation. As a result, because of design similarities of all P series dummies, our engineering judgment was the 10-year-old TNO dummy would not be suitable for use in crash testing. Subsequently, TNO began developing the Q series dummies, which appear likely to be more biofidelic, stable and reliable than their predecessor. The dummies are still in development and are not available for use now.
13. The Hybrid III 6-year-old dummy weighs about 51.5 lb, whereas the Hybrid II dummy weighs approximately 48 lb. A 50th percentile 6-year-old weighs 51 lb.
14. The agency originally began this project by evaluating whether weight could be added to the HIII 6-year-old dummy by way of a weighted vest. We purchased a weighted vest from First Technology Safety Systems, a dummy manufacturer, to evaluate its design. The weights were contained in pouches located over the abdomen in the front and over the lower back of the dummy's posterior. On inspection of the vest on the dummy, we decided that this design would be unacceptable for use in compliance testing. Because the weights were not rigidly attached to the dummy, the weights could rattle or even slap in a dynamic event and possibly create noisy data signals in the dummy's instrumentation responses. Further, the vest was somewhat bulky, and the agency was concerned that it could affect the positioning of the dummy within the restraint system. The agency therefore concluded that the weighted vest concept was not a feasible alternative.
15. In addition, the agency also believed that, for pulse durations shorter than approximately 25 mses, the HIC 70015 requirement is more stringent than HIC 100036.
16. The FMVSS No. 208 final rule proposed both "out- of-position" and "in-position" critical values for Nij. The out-of-position values are applicable to the air bag loading environment where the loading to the neck is due to the occupant being out of a normal seating position in close proximity to the air bag. In- position critical values are applicable for conditions such as child restraints, where the occupant is properly positioned and neck forces and moments result from inertial loadings.
17. NHTSA's preliminary regulatory evaluation (PRE) discusses issues relating to the potential costs, benefits and other impacts of this regulatory action. The PRE is available in the docket for this rule and may be obtained by contacting Docket Management at the address or telephone number provided at the beginning of this document. You may also read the document via the Internet, by following the instructions in the section below entitled, "Viewing Docket Submissions." The PRE will be listed in the docket summary.