Federal Motor Vehicle Safety Standards: Seat Belt Assembly Anchorages; Incorporation by Reference

Federal RegisterSep 17, 2024

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DEPARTMENT OF TRANSPORTATION

National Highway Traffic Safety Administration

49 CFR Part 571

[Docket No. NHTSA-2024-0025]

RIN 2127-AL05

Federal Motor Vehicle Safety Standards: Seat Belt Assembly Anchorages; Incorporation by Reference

AGENCY:

National Highway Traffic Safety Administration (NHTSA), Department of Transportation (DOT).

ACTION:

Final rule.

SUMMARY:

This document amends the procedures for testing the strength of seat belt anchorages in Federal Motor Vehicle Safety Standard No. 210, “Seat Belt Assembly Anchorages.” The amendments clarify the positioning of the test device currently specified in the standard and add an optional test device (and corresponding test procedures) as a certification alternative. These amendments respond to an earlier court decision which found that the regulatory test procedures do not provide manufacturers adequate notice of how NHTSA would conduct the test.

DATES:

Effective date:

This rule is effective October 17, 2024.

Incorporation by reference date:

The incorporation by reference of certain publications listed in this rule is approved by the Director of the Federal Register as of October 17, 2024.

Compliance date:

The compliance date is September 1, 2027, with optional early compliance permitted. Multi-stage manufacturers and alterers would have an additional year to comply.

Petition for reconsideration:

Petitions for reconsideration of this final rule must be received not later than November 1, 2024.

ADDRESSES:

Petitions for reconsideration of this final rule must refer to the docket number set forth above and be submitted to the Administrator, National Highway Traffic Safety Administration, 1200 New Jersey Avenue SE, Washington, DC 20590. Note that all petitions received will be posted without change to

https://www.regulations.gov,

including any personal information provided.

Confidential Business Information:

If you wish to submit any information under a claim of confidentiality, you should submit your complete submission, including the information you claim to be confidential business information, to the Chief Counsel, NHTSA, at the address given under

FOR FURTHER INFORMATION CONTACT.

In addition, you should submit a copy, from which you have deleted the claimed confidential business information, to Docket Management at the address given above. When you send a submission 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). Please see further information in the Regulatory Notices and Analyses section of this preamble.

Privacy Act:

The petition will be placed in the docket. Anyone is able to search the electronic form of all documents received into any of our dockets by the name of the individual submitting the comment (or signing the comment, if submitted on behalf of an association, business, labor union, etc.). You may review DOT's complete Privacy Act Statement in the

Federal Register

published on April 11, 2000 (65 FR 19477-78) or you may visit

https://www.transportation.gov/individuals/privacy/privacy-act-system-records-notices.

Docket:

For access to the docket to read background documents or comments received, go to

www.regulations.gov,

or the street address listed above. Follow the online instructions for accessing the dockets.

FOR FURTHER INFORMATION CONTACT:

For non-legal issues, you may contact Mr. Joshua McNeil, Office of Crashworthiness Standards, Telephone: (202) 366-7612; Email:

Joshua.McNeil@dot.gov;

Facsimile: (202) 493-2739. For legal issues, you may contact Mr. John Piazza, Office of Chief Counsel, Telephone: (202) 366-2992; Email:

John.Piazza@dot.gov;

Facsimile: (202) 366-3820. The address of these officials is: the National Highway Traffic Safety Administration, 1200 New Jersey Avenue SE, Washington, DC 20590.

SUPPLEMENTARY INFORMATION:

Table of Contents

I. Executive Summary

II. Background

A. FMVSS No. 210

B. 2012 Notice of Proposed Rulemaking

C. 2015 Supplemental Notice of Proposed Rulemaking

D. 2018 Notice of Availability

E. International and Industry Consensus Anchorage Strength Requirements and Test Procedures

III. NHTSA's Statutory Authority

IV. NHTSA Research and Testing

A. Research Docketed With the NPRM

B. Research Docketed in 2018

V. Final Rule and Response to Comments

A. Force Application Device

1. FAD Design

i. Durability and Strength of FADs

ii. FAD Material and Potential Seat Belt Slippage

iii. Weight of the FADs

iv. Dimensions of the FADs

v. FAD Abdomen Area

vi. Bridged Pull Yoke

vii. Clarifying Attachment to Force Actuator

viii. Human Form Design

ix. Effect on Seat Back Deformation

x. Missing Tolerance Values

xi. Design Drawings and Supplemental 3-D Data

2. FAD Test Procedure

i. Positioning Procedure

ii. Selections of FAD1 or FAD2 and Contact Between Adjacent FADs and Vehicle Interior

iii. Use of FAD2 on Buses and Heavy-Duty Trucks

iv. Bottoming Out of Hydraulic Cylinders

3. Repeatability

4. Equivalence With the Body Blocks

5. Familiarity With the FAD by Stakeholders

6. Testing Costs

i. Costs of Testing With the FAD

ii. Potential Re-Certification Costs

7. Incorporation by Reference

B. Body Blocks

1. Retention of Body Blocks and Appropriateness of Specifying Zones for Body Block Placement

2. Reference Point for Determining Zone Locations

3. Applicability of Zones to a Range of Vehicle and Seat Designs and Factors Affecting Position of Body Blocks at Preload

4. Size of Zones, Variability of Test Results, and Effect on Compliance

5. Laboratory Safety Concerns

6. Lack of Regulatory Test Procedure Language and Requested Public Workshop

7. Alternative Solutions Suggested by NPRM Commenters

C. Issues Common to the FAD and Body Blocks

1. Shoulder Belt Height Adjustment

2. Preload Force Magnitude and Duration

3. Seat Adjustment

4. Seat Belt Pretension and Routing

5. Hold Time Requirement

6. Force Application Angle

7. Use of a Dedicated Test Belt

8. Testing of Side-Facing Seats

9. Compliance Options

10. Regulatory Alternatives

11. Leadtime

VI. Regulatory Notices and Analyses

VII. Appendices to the Preamble

I. Executive Summary

Federal Motor Vehicle Safety Standard (FMVSS) No. 210, “Seat belt assembly anchorages,” establishes requirements for seat belt anchorages, which are the part of the vehicle that transfers seat belt loads to the vehicle structure. The standard sets out a variety of requirements for seat belt

anchorages, including performance requirements that ensure that the anchorages are strong enough to remain attached to the vehicle structure in a crash. The standard requires seat belt anchorages to withstand specified forces when tested according to the test procedures specified in the standard. The test forces are applied to the seat belts by test devices referred to as “body blocks,” which essentially take the place of an occupant. The body blocks are placed on the seat, secured with the seat belt, and attached to a force actuator that applies the specified test forces. The standard has included the anchorage strength requirements and body blocks since its inception in 1967. International regulations and industry consensus standards also contain seat belt anchorage strength requirements, which, although different from FMVSS No. 210 in various ways, generally mirror FMVSS No. 210 by specifying the use of body blocks similar to the FMVSS No. 210 body blocks.

This final rule amends the test procedures for the standard's seat belt anchorages strength requirements. The current standard specifies a variety of aspects of the test procedure, but does not specify precisely where on the vehicle seat NHTSA will position the body blocks at the start of the test before the test loads are applied. This lack of specificity has, in the past, resulted in manufacturers conducting compliance testing differently from NHTSA. As a result, in the late 1990s the U.S. Court of Appeals for the District of Columbia Circuit ruled that NHTSA had failed to provide adequate notice of where on the vehicle seat NHTSA would position the body block. As a result, NHTSA was not able to compel the recall of the vehicles at issue in that case, which had failed the anchorage strength test when tested by NHTSA.

To address the issues identified by the court, and to make the seat belt anchorage strength test easier to carry out, in 2012 NHTSA published a notice of proposed rulemaking (NPRM) (77 FR 19155, March 30, 2012) that proposed replacing the body blocks with a new test device referred to as the Force Application Device (FAD). The FAD consists of an upper torso portion and a pelvic portion hinged together to form a one-piece device that roughly resembles the human form. NHTSA developed two different size versions of the FAD, referred to as FAD1 and FAD2. The test procedure proposed for the FAD addressed the issues about the positioning of the test device that had been identified by the Court of Appeals. NHTSA also explained in the NPRM that it believed that the FAD would be easier to use than the body blocks. NHTSA developed the FAD independently and it has not yet been adopted outside of the United States.

The agency received a variety of comments in response to the NPRM. Vehicle manufacturers and seat suppliers stated several concerns with the FAD and the corresponding seating procedure, including the design and performance of the FAD, lack of knowledge or experience testing with the FAD, harmonization, and cost.

After considering these comments, NHTSA decided to evaluate the feasibility of retaining the body blocks and refining the regulatory test procedure to specify where on the seat NHTSA would position the body blocks. In 2015, NHTSA published a supplemental notice of proposed rulemaking (SNPRM) (80 FR 11148, March 2, 2015) in which it explained that it was considering specifying, either instead of or as an alternative to the FAD, a three-dimensional zone(s) with respect to the seat in which the body blocks would be positioned. The SNPRM explained that this contemplated procedure using zones was modelled after a similar procedure in FMVSS No. 222, School bus passenger seating and crash protection. By refining the current test procedure to include these zones, NHTSA stated that it intended the standard clarify how the agency will position the body blocks. The agency also stated that it had initiated research to develop the zones and that the research would evaluate the zone concept across different vehicle types and seat configurations and establish appropriate zone boundaries to ensure that the procedure is feasible and practicable for all vehicles. In 2018, NHTSA published a notice of availability (83 FR 16280, April 16, 2018) and docketed reports and data on the additional research it had completed on the development of the body block zones, as well as the FAD.

NHTSA received a variety of comments in response to the SNPRM. These included, among other things, concerns with whether the zones would work for all vehicles and vehicle types (especially for heavy-duty trucks and buses, which have different seats from passenger vehicles); the size of the zones and potential variability in the test results; and the need for existing vehicle platforms to be re-certified using the new zones. Several SNPRM commenters supported the continued use of the body blocks in addition to the option of using the FAD.

Summary of Final Rule

The final rule amends FMVSS No. 210 to specify zones for the placement of the body blocks and to include the FAD as an alternative compliance option (at the manufacturer's choice).

Placement Zones for the Body Blocks

The finalized zones are the zones specified in the research report NHTSA docketed in 2018. NHTSA's testing shows that the zones are valid for a wide range of vehicles, including medium- and heavy-duty vehicles. The zones are based on data from a range of different vehicles and were mathematically expanded to accommodate an even wider range of vehicles. To ensure that the zones would apply to a wide variety of vehicles and seats, the agency's research considered the factors identified by the SNPRM commenters, as well as other factors that may affect body block position.

While the zones are large enough to account for a variety of vehicles and seat types, they are still relatively modest in size, and there is no data or evidence that suggests that there will be large variability in force vectors or test results. For the same reasons, we have not seen any data or evidence to suggest that testing to the final zones will result in different compliance outcomes compared to the existing test procedure. The current test procedure has no constraints on the positioning of the body blocks. The refined test procedure in this final rule establishes allowable zones for the positioning of the body blocks, which have been used for testing anchorage strength since the standard's inception in 1967. Use of the body blocks within the allowable zones reduces the set of permissible test conditions, which also reduces the variability of the test.

Force Application Device

The final rule specifies the FAD as an optional alternative to the body blocks that manufacturers may choose to certify compliance. Manufacturers that prefer to certify using the body blocks may continue to do so. Design drawings of the FAD1 and FAD2 are incorporated by reference into the final rule and are sufficiently detailed to allow manufacturers to fabricate the devices. In addition to the two-dimensional engineering drawings incorporated by reference in the final rule, NHTSA is making three-dimensional design drawings available for reference purposes (

e.g.,

to facilitate fabrication). In response to comments, the final rule also clarifies some of the proposed

regulatory text. NHTSA estimates the cost of each FAD to be approximately $8,000.

We are providing a two-year lead time for the use of the body blocks and the FAD as established by this final rule. Providing vehicle manufacturers the option to continue to use the current body blocks or the FAD for certification should alleviate the lead time concerns expressed by commenters to the NPRM.

This final rule is not significant and so was not reviewed by the Office of Management and Budget under E.O. 12866.

II. Background

A. FMVSS No. 210

FMVSS No. 210, “Seat belt assembly anchorages,” applies to passenger cars, multipurpose passenger vehicles (“MPVs”), trucks, and buses of all weights. The standard establishes requirements for seat belt assembly anchorages (“seat belt anchorages”). Seat belt anchorages are any component, other than the webbing or straps, involved in transferring seat belt loads to the vehicle structure, including, but not limited to, the attachment hardware, seat frames, seat pedestals, the vehicle structure itself, and any part of the vehicle whose failure causes separation of the belt from the vehicle structure. The standard's requirements ensure that the anchorages are properly located for effective occupant restraint and are sufficiently strong so that they remain attached to the vehicle structure in a crash. As to the latter, the standard requires seat belt anchorages to withstand specified forces when tested according to the procedures specified in the standard. This final rule amends the test procedures for the standard's seat belt anchorage strength requirements.

Since its inception in 1967, FMVSS No. 210 has included anchorage strength requirements, tested with body blocks.

Under the standard, seat belt anchorages for lap-belt only belts (referred to as “Type 1” belts

) must withstand a 22,241 Newton (N) (5,000 pound (lb)) force. Seat belt anchorages for combination lap/shoulder belts (“Type 2 belts”

) must withstand a 13,345 Newton (N) (3,000 lb) force applied to the lap belt portion of the seat belt assembly simultaneously with a 13,345 N force applied to the torso (

i.e.,

shoulder) belt portion of the seat belt assembly (“test force” or “test load”). Because Type 2 belts are generally required for most seating positions and vehicle types, for ease of explanation the preamble discussion will assume that testing is for a Type 2 belt unless otherwise noted. These forces are applied to the lap belt portion of the belt by a pelvic body block and the torso portion of the belt by a torso body block. The torso and pelvic body blocks are separate test devices that are positioned at each designated seating position tested. The standard specifies the shape, dimensions, and the covering (foam) of the body blocks, but otherwise, the construction of the body block may vary.

See Figure 1 for depictions of the torso and pelvic body blocks.

See

32 FR 2408, 2415-2416 (February 3, 1967) (Initial Federal Motor Vehicle Safety Standards).

See

49 CFR 571.210, S3 (definition of “Type 1 seat belt assembly”).

See

49 CFR 571.210, S3 (definition of “Type 2 seat belt assembly”).

See

FMVSS No. 210, Fig. 2A (pelvic body block), Fig. 2B (optional pelvic body block for center seating positions), and Fig. 3 (torso body block).

See also

FMVSS No. 222, “School bus passenger seating and crash protection,” Figure 2 (pelvic body block). The FMVSS No. 222 pelvic body block is only used for school buses with a GVWR of 4,536 kilograms (kg) (10,000 pounds) or less.

ER17SE24.012

The body blocks are placed on the seat, secured with the seat belt,

and attached (typically, with heavy-duty chains) to a force actuator that applies the specified test forces. Although not currently specified in the regulatory text of FMVSS No. 210, the laboratory test procedure for the standard specifies a preload in addition to the test force.

Specifically, after the body blocks are secured with the seat belt, the force actuator applies a preload equal to 10% of the test force. While at the preload level, photographs and measurements of the load application angles are taken. The load is then increased to the full test force. The test force must be attained within 30 seconds and held for 10 seconds. The anchorage, attachment hardware, and attachment bolts must withstand this loading;

permanent deformation or rupture of a seat belt anchorage or its surrounding area is not considered to be a failure if the required force is sustained for the specified time.

Typically, for compliance testing, all seats in the vehicle are tested, starting from the front of the vehicle. After the front seats have been tested, they may be removed to facilitate access to the rear seats.

The seat belt may be replaced with material whose breaking strength is greater than or equal to the breaking strength of the webbing for the seat belt assembly installed as original equipment at that seating position. S5.

Laboratory Test Procedure for FMVSS 210 Seat Belt Assembly Anchorages. U.S. Department of Transportation, National Highway Traffic Safety Administration (TP-210-09) (Feb. 7, 1994),

available at https://www.nhtsa.gov/sites/nhtsa.gov/files/2023-06/tp-210-09-tag.pdf.

The Office of Vehicle Safety Compliance (OVSC) publishes, for each standard, a laboratory test procedures manual containing more detailed test procedures and laboratory practices for NHTSA-contracted test laboratories. This is distinguished from the test procedures set out in the regulatory text of the FMVSS.

S4.2.1, S4.2.2.

S4.2.3.

Neither the standard nor the laboratory test procedure specifies precisely where on the vehicle seat NHTSA will position the body blocks. This lack of specificity has, in the past, resulted in manufacturers conducting compliance testing differently from NHTSA, as illustrated in an enforcement action brought against Chrysler in the 1990s for apparent noncompliance with FMVSS No. 210.

In the compliance test at issue there, NHTSA positioned the pelvic body block away from the seat back. Chrysler argued that its vehicle met the anchorage strength requirements when tested with the body block placed against the seat back, and that NHTSA's placement of the pelvic body block forward of the seat back was not required by FMVSS No. 210. Ultimately, the U.S. Court of Appeals for the District of Columbia Circuit determined that NHTSA had failed to provide adequate notice about the correct placement of the pelvic body block and ruled that NHTSA could not compel Chrysler to recall the vehicles.

See United States

Chrysler Corp.,

158 F.3d 1350 (D.C. Cir. 1998).

In addition, setting up the body blocks for testing can be cumbersome because the torso body block does not sit on the seat and must be supported by someone or something as the preload is applied to the shoulder portion of the seat belt. Doing so can be challenging when testing multiple adjacent seating positions simultaneously because the preload must be maintained on body blocks that are already set up until all the body blocks are set up in a manner that minimizes the chance of load interference, and all seating positions are ready for the full test force. This setup typically necessitates two technicians and, potentially, multiple attempts to run the test, because the torso body block tends to come out of position.

B. 2012 Notice of Proposed Rulemaking

To address the issues identified by the

Chrysler

decision and the challenges associated with the use of the body blocks, on March 30, 2012, the agency published an NPRM.

In that NPRM, NHTSA proposed to amend FMVSS No. 210 to replace the pelvic and torso body blocks with a new Force Application Device (FAD).

77 FR 19155 (March 30, 2012).

The FAD consists of an upper torso portion and a pelvic portion hinged together to form a one-piece device that roughly resembles the human form. NHTSA developed two different size versions of the FAD, referred to as FAD1 and FAD2. The external dimensions of the FAD1 are based on digital data developed by the University of Michigan Transportation Research Institute (UMTRI) as a representation of the 50th percentile adult male.

The FAD1, which weighs 55.8 kg (123 lb), replicates the torso and lap portions of what UMTRI calls the “Golden Shell” and reproduces the seat belt angles produced when a seat belt is fastened around a 50th percentile adult male. NHTSA developed the specifications for the smaller FAD2 to use at designated seating positions (DSPs) that are too narrow in width to accommodate the FAD1, such as some rear center seats in passenger cars and MPVs. The FAD1 and the FAD2 are specified in approximately 32 drawings that were docketed with the NPRM. As requested by Faurecia S.A. Automotive Seating, NHTSA provided the Initial Graphics Exchange Specification files of the 3-D contours for the torso and pelvis portions of the FAD1 and FAD2, and in a docketed memo informed the public that the files were available upon request.

NHTSA estimated the cost of each FAD to be approximately $8,000.

Robbins, D. 1985. “Anthropometric Specifications for Mid-Size Male Dummy,” Volume 2, UMTRI, DOT HS 806 716.

NHTSA-2012-0036-0020. These reference materials would not be incorporated into FMVSS No. 210. Instead, they are intended only for reference purposes (

e.g.,

to facilitate fabrication and inspection of parts).

The proposed regulatory text specified how the FADs would be seated at the outset of the strength test (

i.e.,

before any load was applied to the belt). Like the existing body blocks, the FADs are secured with the seat belt(s) and are attached to a force actuator that applies the specified test forces. For combination lap/shoulder belts (Type 2 seat belts), the force actuator is connected to separate connection points on the torso and lap portions of the FAD to apply the required forces to the lap and shoulder portions of the belt simultaneously; for lap belt-only anchorages, a bridged pull yoke is used to connect the connection points of the torso and lap portions of the FAD, so that they are jointly pulled.

As to which FAD the agency would use for a particular designated seating position, NHTSA proposed that if it was not testing in accordance with S4.2.4,

it would use the FAD1. For tests conducted in accordance with S4.2.4, NHTSA proposed that, if after the FAD1 devices are installed, but prior to conducting the test, there is contact between the FAD1s (or if there is contact between the FAD1s that prevent them from fitting side-by-side), an inboard FAD1 would be replaced with a FAD2. (As discussed later in this document (in section V.C.2.b), the proposal was not clear whether this contact was prior to the preload force or prior to when the test force was applied to the FADs.) If there is still contact between the FADs, and if there is another inboard DSP, an additional inboard FAD1 would be replaced with a FAD2, and so on. If the contact continues with all inboard DSPs with FAD2s, the FAD1 in the right outboard

DSP would be replaced with a FAD2. If there is still contact between the FADs, the FAD1 in the left outboard DSP would be replaced with a FAD2.

Briefly stated, S4.2.4 specifies that anchorages, attachment hardware, and attachment bolts shall be tested by simultaneously loading them if: (a) the DSPs are common to the same occupant seat and face the same direction, or (b) the DSPs are not common to the same occupant seat, but a DSP has an anchorage that is within 305 mm of an anchorage for one of the adjacent DSPs, provided that the adjacent seats face in the same direction.

The agency received 14 comments in response to the NPRM from 13 organizations and an individual. (One entity submitted two comments.) Commenters included five vehicle manufacturer associations, three medium and/or heavy-duty truck manufacturers, two light vehicle manufacturers, two seat suppliers, one bus manufacturer, and one test facility. The commenters stated several concerns with the FAD and the corresponding seating procedure. These concerns included issues such as the design and performance of the FAD, harmonization, the proposed test procedure, and cost. (The comments are discussed in detail later in this document.)

C. 2015 Supplemental Notice of Proposed Rulemaking

After considering the comments on the NPRM, the agency decided to evaluate the feasibility of maintaining the current body blocks and refining the regulatory test procedure to specify where on the seat NHTSA would position the body blocks. On March 2, 2015, NHTSA published an SNPRM.

80 FR 11148 (March 2, 2015).

The agency explained that it was considering specifying, either instead of or as an alternative to the FAD, zones within which the current body blocks would be placed. The procedure would establish a three-dimensional region with respect to the seat in which the body blocks would be positioned; there would be two zones, one for the torso body block, and one for the pelvic body block. The pelvic body block would be positioned within the pelvic body block zone and the torso body block would be positioned within the torso body block zone. This positioning would be accomplished by first applying a preload force (of 1,335 N) to each body block. While this preload force is being applied, the torso and pelvic body blocks would be positioned so that a specified “target” on each block is within each of the applicable zones.

As explained in the SNPRM, this positioning is based on the similar procedure specified in FMVSS No. 222, School bus passenger seating and crash protection.

FMVSS No. 222 includes a “quasi-static” test requirement to help ensure that school bus seat backs incorporating lap/shoulder belts are strong enough to withstand both the forward pull of the torso belts and the forces imposed on the seat from unbelted passengers to the rear of the belted occupants in a crash. That procedure, which uses the FMVSS No. 210 torso body block (but not the pelvic body block), establishes a zone in which the torso body block must be located. Specifically, FMVSS No. 222 specifies that the torso body block is placed in the seat, secured behind the seat belt, and a preload of 600 N is applied. This preload force is, depending on the weight of the vehicle being tested (because the test forces specified in FMVSS No. 222 depend on vehicle weight), approximately 8 percent to 18 percent of the full test load. After the preload application is complete, the origin of the torso body block radius at any point across the torso body block thickness must lie within a zone defined by specified boundaries. The forward boundary of this zone is established by a transverse vertical plane of the vehicle located 100 mm longitudinally forward of the seating reference point (SgRP).

The upper and lower boundaries of the zone are 75 mm above and below the horizontal plane located midway between the horizontal plane passing through the school bus torso belt adjusted height (specified in S3 of FMVSS No. 210), and the horizontal plane 100 mm below the SgRP. After the 600 N preload is applied and the torso body block is verified as being within the specified zone, the required test forces are applied.

See

73 FR 62744 (October 21, 2008) (final rule upgrading FMVSS No. 222).

The seating reference point (SgRP) is defined in 49 CFR 571.3.

The required test forces for FMVSS No. 222 vary from 3,300 N to 7,500 N, depending on the weight of the bus and the type of seat.

NHTSA explained in the SNPRM that it was planning to develop separate zones for the placement of the torso and pelvic body blocks to be specified in FMVSS No. 210. By refining the current test procedure to include these zones, NHTSA stated that it intended the standard to be clearer as to how the agency will position the body blocks. The agency explained that it did not intend to increase the stringency of the standard. The agency also stated that it had initiated research to develop the zones and stated that the research would evaluate the zone concept across different vehicle types and seat configurations and establish appropriate zone boundaries to ensure that the procedure is feasible and practicable for all vehicles.

NHTSA received nine comments in response to the SNPRM: three vehicle manufacturer associations, one vehicle manufacturer, three suppliers, one foreign government, and one individual. The commenters raised several concerns and issues with the SNPRM. These concerns included, among other things, concerns with the appropriateness of the zone concept, the size of the zones and potential variability in the test results, and specific concerns with the test procedures. There were also several additional comments about the FADs. Several SNPRM commenters supported the continued use of the body blocks in addition to the option of using the FAD. Many of the compliance concerns raised in response to the NPRM were also present in response to the SNPRM, since the agency proposed refining the test procedure for the continued use of the body blocks. For instance, commenters raised concerns regarding recertification, lead time, harmonization, and costs associated with recertification and potential redesign. These comments are discussed in detail later in this document.

D. 2018 Notice of Availability

In 2018, NHTSA published a notice of availability

and docketed reports and data on the additional research it had completed on the FAD and the development of the body block zones. NHTSA also docketed test reports describing additional testing conducted with the FAD. This research is discussed in more detail in section IV, NHTSA Research and Testing, and elsewhere in the preamble where relevant. NHTSA received two comments from trade groups in response to the 2018 notice of availability (a list of the comments received in response to the NPRM, SNPRM, and notice of availability is provided in appendix A of this document). The comments recommended, among other things, that NHTSA issue and provide opportunity to comment on a pre-final rule draft test procedure and schedule a compliance workshop. These comments are discussed in detail later in this document.

83 FR 16280 (April 16, 2018).

E. International and Industry Consensus Anchorage Strength Requirements and Test Procedures

International regulations and industry consensus standards also establish seat belt anchorage strength requirements. These include United Nations Regulation No. 14 (ECE R14), Transport Canada's Technical Standards Document No. 210, Australian ADR 05, and SAE Standard J384 (2014). As explained below, all these standards specify pelvic and torso body blocks similar to the FMVSS No. 210 body

blocks but do differ somewhat from the FMVSS No. 210 test procedures.

The NPRM made mention of an ISO standard (TR 1417-1974) but that has since been withdrawn.

United Nations Regulation No. 14 (ECE R14) and Australian ADR 5, Anchorages for Seatbelts

ECE R14 provides the uniform provisions concerning the approval of vehicles regarding seat belt anchorages, including the general test requirements for seat belt anchorages. The load requirements differ somewhat from FMVSS No. 210 (

e.g.,

FMVSS No. 210 requires 13,345 N and ECE R14 requires 13,500 N ± 200 N) and there are different load requirements for different vehicle types. For example, category M1 and N1 vehicles (passenger cars, multipurpose passenger vehicles, vans, pick-ups, and light trucks) have similar requirements as FMVSS No. 210 but M3, N3, and other vehicle types have lower load requirements. R14 also specifies different load requirements for rear-facing and side-facing designated seating positions (same as the requirements for M3 vehicles). As far as achieving the required load and the holding requirement, ECE R14 allows achieving the load in 60 seconds (versus FMVSS No. 210 requirement of 30 seconds) and the hold requirement is 0.2 seconds (versus FMVSS No. 210 requirement of 10 seconds). Australian ADR 5, Anchorages for Seatbelts, follows the ECE R14 requirements.

ECE R14 and FMVSS No. 210 specify similar body blocks for testing the seat belt anchorages.

R14 also specifies some aspects of the test procedure not currently specified in FMVSS No. 210. R14 specifies the placement of the body blocks at preload; it specifies that the belt be pulled tight against the pelvic block and that the torso block be pushed back into the seat back while the belt is pulled tight around it. R14 also specifies the location of the pivot point on the torso body block. R14 specifies a preload of 10 percent of the full load, with a tolerance of ±30 percent. Another distinction between FMVSS No. 210 and ECE R14 is that ECE R14 also has a distinct pelvic block for testing side-facing seats and specifies that the direction of the test load be forward in relation to the vehicle.

For example, the regular size pelvic block and the torso block dimensions have slight variations (

e.g.,

for torso block R200 vs R203; for pelvic block the width is 406 mm vs 356 mm and R520 vs R495, etc.).

Transport Canada's Technical Standards Document No. 210

Transport Canada's Technical Standards Document No. 210, Seat Belt Anchorages, is based on FMVSS No. 210,

and the two standards are nearly identical. The same pelvic and torso body blocks are used to test the strength of the seat belt anchorages at the same test loads for Type 1 and Type 2 seat belts and with the same hold time of 10 seconds once the test load is achieved. Like FMVSS No. 210, the Canadian standard lacks a specification for the placement of the body blocks at preload. The standard specifies a procedure for adjustments in the event of interference between the pelvic body block and belt buckle. A 50th percentile anthropomorphic test dummy (ATD) is placed at each seating position with the seat belt fastened around it and all slack is removed from the webbing. At this position, the belt webbing is marked and the ATDs are removed. The body blocks are placed “against the back of the seat” and the belts are fastened around the blocks. The blocks are moved forward if the belt buckle seems to be susceptible to damage upon inspection, but the blocks are not to be moved further forward than the mark made with the ATD placed in the seat. The approach of using an ATD to address interference between the block and the belt buckle differs from NHTSA's test procedure for FMVSS No. 210.

https://tc.canada.ca/sites/default/files/migrated/tsd_210_en.PDF

(

last accessed

June 14, 2024).

SAE J384 (Rev. 2014) and J383 (Rev. 2014)

SAE J384 (Rev. 2014) specifies test procedures for seat belt anchorages and SAE J383 (Rev. 2014) provides design recommendations for seat belt anchorage locations. SAE J384 is nearly identical to FMVSS No. 210, with similar body block specifications (the torso body block has the same dimensions, but also includes a pull arm), test loads, and the option to replace the seat belt webbing with other material. The standard specifies a preload of 10%. The body blocks are positioned at each DSP and the seat belts are positioned around the blocks “to represent design intent routing.”

III. NHTSA's Statutory Authority

NHTSA is adopting this rule pursuant to its authority under the National Traffic and Motor Vehicle Safety Act, 49 U.S.C. 30101

et seq.

(“Safety Act”). Under the Safety Act, NHTSA (under authority delegated by the Secretary of Transportation

) is responsible for prescribing motor vehicle safety standards that are practicable, meet the need for motor vehicle safety, and are stated in objective terms.

“Motor vehicle safety” is defined in the Motor Vehicle Safety Act as “the performance of a motor vehicle or motor vehicle equipment in a way that protects the public against unreasonable risk of accidents occurring because of the design, construction, or performance of a motor vehicle, and against unreasonable risk of death or injury in an accident, and includes nonoperational safety of a motor vehicle.”

“Motor vehicle safety standard” means a minimum performance standard for motor vehicles or motor vehicle equipment.

When prescribing such standards, NHTSA must consider all relevant, available motor vehicle safety information.

NHTSA must also consider whether a proposed standard is reasonable, practicable, and appropriate for the types of motor vehicles or motor vehicle equipment for which it is prescribed and the extent to which the standard will further the statutory purpose of reducing traffic accidents and associated deaths.

In promulgating this rule, NHTSA carefully considered all the aforementioned statutory requirements. NHTSA evaluates this rule with respect to these requirements in section V of the preamble where relevant.

49 CFR 1.95.

49 U.S.C. 30111(a).

49 U.S.C. 30102(a)(9).

Section 30102(a)(10).

Section 30111(b)(1).

Section 30111(b)(3)-(4).

IV. NHTSA Research and Testing

This final rule is supported by a variety of research. Some of this research was docketed with the NPRM. Research was also conducted and docketed after the NPRM but before issuance of this final rule. NHTSA briefly summarizes the agency's research below. More specific discussion of various aspects of this research is available in the cited test reports, the NPRM, and in subsequent sections of this document. This research is summarized in Table 1.

Table 1—Summary of Research Supporting Final Rule

Research

Summary

Docket ID

Research Docketed with NPRM

Final Report: Development of a Combination Upper Torso and Pelvic Body Block for FMVSS 210 Test

Description of design, materials, and positioning procedures. Analysis of FAD positioning consistency based on testing of nine light vehicles from two-seat sports cars to light-duty trucks. Analysis of FAD anchorage force repeatability based on testing of three seat configurations

NHTSA-2012-0036-0002.

Indicant Test Reports

Full-scale FMVSS No. 210 anchorage strength tests using the FAD on nine vehicles: six passenger cars, an 11-passenger van, a minivan with stow-and-go seating, and an F-150 SuperCab pickup truck

NHTSA-2012-0036-0002.

Repeatability Analysis of the Forces Applied to Seat Belt Anchors Using the Force Application Device

Additional analysis of FAD anchorage force repeatability using the FMVSS No. 214 test procedure and comparing channel measurements differences

NHTSA-2012-0036-0002.

FAD inspection report

Report of drawings and parts lists, drawing revisions, and measurements of multiple FAD devices used in . . .

NHTSA-2012-0036-0002.

FAD drawing packages

Drawing packages for the FAD1 and FAD2

NHTSA-2012-0036-0002.

Research Docketed with Notice of Availability

Body Block Zone Development Report

Report detailing development of body block zones

NHTSA-2012-0036-0041.

Indicant testing of FAD on buses with gross vehicle weight rating (GVWR) >10,000 lb

Full-scale FMVSS No. 210 tests with the FAD in the driver's seat on two school buses and a motorcoach

NHTSA-2012-0036-0042 (school bus), NHTSA-2012-0036-0043 (school bus), NHTSA-2012-0036-0044 (Motorcoach).

Indicant testing on passenger vehicles

Full-scale FMVSS No. 210 tests on passenger vehicles to test body block zone concept and equivalence with the FAD

Honda Fit (sedan)

Simultaneous testing with body blocks and FAD

NHTSA-2012-0036-0036.

Mitsubishi I-Miev (subcompact)

Simultaneous testing with body blocks and FA

NHTSA-2012-0036-0046.

Chevy Suburban (MPV/sports utility vehicle (SUV))

Simultaneous testing with body blocks and FAD

NHTSA-2012-0036-0040.

Ford Fusion (sedan)

Matched pair testing with body blocks and FAD

NHTSA-2012-0036-0034, NHTSA-2012-0036-0035.

Ford C-Max (sedan)

Matched pair testing with body blocks and FAD

NHTSA-2012-0036-0033, NHTSA-2012-0036-0045.

Subaru Impreza (compact)

Matched pair testing with body blocks and FAD

NHTSA-2012-0036-0037, NHTSA-2012-0036-0039.

A. Research Docketed With the NPRM

The research docketed with the NPRM consisted of materials and reports relating to the development and evaluation of the FAD, including extensive full-scale FMVSS No. 210 tests to determine whether the FAD performs equivalently to the existing body blocks.

NHTSA contracted with the engineering consulting firm KARCO Engineering (Karco) to design, manufacturer, and test a new FMVSS No. 210 test device.

Karco also developed the procedure for positioning the FAD in the vehicle seat and assessed the repeatability of the positioning procedure. As explained in the NPRM, three different laboratory technicians were able to place a FAD in a specific test vehicle so that the predetermined measuring points were within

1/4

inches (6.35 mm) of the same point of the same FAD in the same test vehicle placed by the other technicians. FMVSS No. 208, S10.4.2.1, specifies a

1/2

in. (12.7 mm) tolerance for the H-point, so a

1/4

in. (6.35 mm) variability for seating the FAD can be considered reasonable.

NHTSA-2012-0036-0002 (“Final Report: Development of a Combination Upper Torso and Pelvic Body Block for FMVSS 210 Test, Revision A,” May 22, 2003, KARCO Engineering, LLC).

NHTSA also assessed the repeatability of the forces applied to the seat belt anchorages in the FMVSS No. 210 anchorage strength test using the FAD.

Anchorage load cells were mounted to a rigid test rig, the vehicle seat was replaced with a rigid seat, and the seat belt webbing was replaced with high strength webbing. The test configuration was set up in a generic configuration to minimize variability. A FAD1 was positioned, belted, and pulled per the proposed FMVSS No. 210 test procedure. This test was repeated four times, and a statistical analysis was performed on both the peak force values as well as time-based metrics. The coefficient of variance (CV) was used to assess the variability of the peak values for each data channel to assess the repeatability of the test results and to rate the channels based on established CV acceptance criteria. The data and analysis presented in the repeatability analysis demonstrate that the forces applied to the seat belt anchor points by the FAD using the FMVSS No. 210 procedure are repeatable.

NHTSA-2012-0036-0002 (“Repeatability Analysis of the Force Applied to Safety Belt Anchors Using the Force Application Device (May 2009)”). KARCO also assessed the repeatability of the forces recorded at the seat belt anchorages and compared these to the forces recorded with the current body blocks.

See supra

note 15, KARCO Final Report. However, this force repeatability study did not adhere strictly to the proposed test procedure, so NHTSA conducted a new analysis (discussed in the next paragraph) that did strictly adhere to the proposed test procedure.

See

NPRM at 19157.

NHTSA then conducted full-scale FMVSS No. 210 anchorage strength tests (“indicant tests”

) on nine vehicles: six passenger cars, an 11-passenger van, a

minivan with stow-and-go seating, and an F-150 SuperCab pickup truck.

The purpose of the tests was to determine whether the FAD performed equivalently to the existing body blocks, and to evaluate the overall performance and usability of the FADs. Every seat in each vehicle was tested; seats in the same row were tested simultaneously. The FAD1, FAD2, and the body blocks (pelvic and torso) were positioned in adjacent seating positions, with the FAD1 in the left seat, the current upper torso and pelvic body blocks in the right seat, and the FAD2 in the center seat (if present). The FADs were positioned using the proposed seating procedure.

There were no test failures. The testing also showed some advantages of the FAD compared to the current body blocks: the FADs were easier to position, and the hydraulic test load application cylinders were less likely to bottom out when testing seating positions with load limiters.

We use the term “indicant” test, as opposed to “compliance” test, because NHTSA was not testing these vehicles to determine whether they comply with the standard.

NHTSA-2012-0036-0002 (test reports for each indicant test).

With respect to the body blocks, neither the standard nor the laboratory test procedure currently specifies precisely where on the vehicle seat the body blocks should be positioned, so the laboratory technicians had no procedure to follow for this.

B. Research Docketed in 2018

After the SNPRM was published in 2015, the agency conducted research to develop the body block zones and to further evaluate the FAD. There were three phases of this research and NHTSA docketed the research in 2018.

The first phase of research involved indicant anchorage strength tests on nine vehicles (described below) with the FAD and/or the body blocks.

This testing had two purposes. One was to validate a preliminary zone concept for the initial positioning (at preload) of the existing pelvic and torso body blocks. The other purpose was to respond to concerns voiced by commenters to the NPRM. The nine indicant tests previously performed to develop the NPRM involved testing the FAD and body blocks simultaneously in the same vehicle. Commenters to the NPRM stated that this testing might not accurately represent the performance of the seat belt assembly anchorages in an actual compliance test, which would use (if the FAD were adopted as proposed) only the FAD. To address this concern, in this phase of research NHTSA performed some of the indicant tests with only the FAD or only the body blocks.

NHTSA-2012-0036-0035 (Ford Fusion), NHTSA-2012-0036-0034 (Ford Fusion), NHTSA-2012-0036-0037 (Subaru Impreza), NHTSA-2012-0036-0039 (Subaru Impreza), NHTSA-2012-0036-0033 (Ford C-Max), NHTSA-2012-0036-0040 (Chevrolet Suburban), NHTSA-2012-0036-0036 (Ford Fusion), NHTSA-2012-0036-0045 (Ford C-Max), NHTSA-2012-0036-0046 (Mitsubishi I-Miev).

For all vehicles, only the rear seating positions were tested, because the vehicles NHTSA had that were readily available for testing only had rear seating positions that were viable for testing. The FADs were positioned using the seating procedure proposed in the NPRM. The body blocks were positioned using a preliminary zone concept based on the positioning procedure for the torso body block used in the quasi-static test for lap/shoulder seat belts on school buses in FMVSS No. 222.

The body blocks were subjected to a preload of 1,335 N. This mirrors the current FMVSS No. 210 laboratory test procedure for the body blocks, which specifies a preload of 10% of the target load (1,335 N is ten percent of the full test load specified in FMVSS No. 210 for the lap and shoulder portions of a Type 2 seat belt assembly).

The position of the torso body block was then adjusted, if necessary, so that the origin of the body block radius at any point across the body block thickness was within the zone. To investigate the commenters' concerns about testing the FAD and body blocks simultaneously in the same vehicle, we tested three matched pairs of vehicles (Fusion, C-Max, and Impreza). One vehicle in each pair was tested with only the body blocks, and the other vehicle in the pair was tested with only the FAD. In the other three vehicles, NHTSA tested the body blocks and FAD simultaneously in the rear outboard seats (with the FAD in one seat and the body blocks in the other seat). There were no failures in any of these tests. This testing showed that the zones were viable and that they would not have to be unreasonably large.

See

SNPRM at pg. 11151. The procedure generally followed the FMVSS No. 222 procedure except that the D-ring is used as the reference point instead of the TBAH. For more information, see the docketed test reports. As noted earlier, neither the standard nor the laboratory test procedure currently specifies precisely where on the vehicle seat the body blocks should be positioned. For this testing, the pelvic body block was typically positioned (prior to application of the preload force) such that the centerline of the block and the centerline of the seat were aligned with the back of the block in contact with the seat back.

Laboratory Test Procedure for FMVSS 210 Seat Belt Assembly Anchorages. U.S. Department of Transportation, National Highway Traffic Safety Administration (TP-210-09) (Feb. 7, 1994), pg. 21.

The second phase of research involved development, testing, and validation to establish practicable and repeatable zones for the preload positioning of the pelvic and torso body blocks.

The first phase of testing referred to immediately above served as a proof of concept for the zones. In this second phase of research, the agency developed zones that would be valid for a wide range of vehicles and vehicle types. The agency first determined the factors affecting the position of the body blocks at preload, using a generic test fixture, and used this information to refine the procedure for positioning the body blocks at preload. This refined procedure was used to apply a preload force to the body blocks in five different passenger vehicles (ranging in size from a subcompact to SUVs) with a variety of seat and belt configurations as well as the generic test fixture. Several different parameters (

e.g.,

with and without a wooden positioning fixture for the torso block, preload force

) were systematically varied to reflect the full range of conditions that might affect the position of the blocks at preload. The tests were conducted in the left outboard and center seats (all tested DSPs had Type 2 belts). This resulted in a total of 125 tests. The agency recorded the position of the torso and pelvic body blocks at preload for each test.

The research summarized here is explained in more detail in the docketed report “Development of Positioning Zones for FMVSS No. 210 Body Blocks” (NHTSA-2012-0036-0041).

One of the test parameters the study systematically varied was the preload force. The study measured the body block target locations with preload forces of 1,335 N and 2,224 N. The laboratory test procedure has long specified that the preload be ten percent of the target (test) load. The former preload is ten percent of the test load for the lap and shoulder portions of a Type 2 seat belt assembly, and the latter preload is ten percent of the test load for Type 1 seat belt assemblies.

This data set was then mathematically expanded in two ways. First, because the outboard seat tests were conducted only in the left seating position, and because center seating positions can have the shoulder belt on either the left or right side, this data did not represent the full range of target positions for all seating locations. Therefore, additional data points were calculated for right outboard seating positions and center seating positions with the shoulder belt over the occupant's right shoulder by “mirroring” the Y-coordinate values. These “mirrored” locations represent the right outboard seating positions and center seating positions with the shoulder belt over the occupant's right shoulder. Second, the zones (including the mirrored data points) were expanded to four standard deviations in the X, Y, and Z directions. This expansion of the zones was intended to allow for vehicle configurations not evaluated in the study and future vehicle designs. The result (with the

coordinates of the vertices rounded up to the nearest 5 mm for ease of use) is the zones specified in this final rule. The precise locations of the zones are specified in relation to the SgRP. The dimensions of the zones are summarized in Table 2 (Table 1 of the regulatory text) and Figure 6 in the regulatory text provides a depiction of the body block zones.

Table 2—Body Block Zone Dimensions

Zone

Depth

(mm)

Width

(mm)

Height

(mm)

Pelvic Body Block

205

340

145

Torso Body Block

240

530

245

Two additional steps were taken to further validate the zones. First, an indicant test was carried out on two DSPs in the second row of a Ford Freestar minivan with the body blocks at the longitudinal extremes of the positions recorded in the fleet study.

This test was used to examine if the location of the body block at these extremes had an effect on the seat belt anchorages meeting the load requirements of FMVSS No. 210. The blocks were positioned in the zones and the test was successfully run, with no failures. Second, the zones were validated in heavy-duty vehicles.

The fleet study used to develop the zones involved only light-duty vehicles, the largest of which was a Ford Freestar. The agency verified the zones in two school bus seats and one motorcoach seat. The tested seats are commonly used on large (GVWRs greater than 10,000 pounds) buses and motorcoaches. Each seat had three DSPs. NHTSA applied the preload force and verified that the body blocks could be positioned in the zones at each of these DSPs.

“Development of Positioning Zones for FMVSS No. 210 Body Blocks,” pp. 39-46.

Id.

at pgs. 47-51.

The third phase of research involved indicant tests with the FAD on buses with a GVWR of more than 4,536 kilograms (10,000 pounds). The indicant tests using the FAD docketed with and discussed in the NPRM were on passenger vehicles with GVWRs of less than 10,000 lb. Commenters to the NPRM noted that, at the time the NPRM was published, NHTSA had not tested any heavy-duty vehicles using the FAD and expressed concerns about whether the FAD would perform equivalently to the body blocks in heavy-duty applications (see section V.A.4 below). The objective of the additional indicant testing with the FAD on these buses was to determine whether the FAD affects the stringency of the anchorage strength test on heavy duty vehicle seats and to assess how the FAD performs in these tests. The agency performed three indicant tests with the FAD in the driver's seat of three different buses: A school bus with a pedestal-type seat;

a school bus with an air suspension seat;

and a motorcoach with an air suspension seat.

The tests were conducted with the driver's seats installed in the buses, using the proposed FAD positioning procedures. All the seat belt anchorages tested met the FMVSS No. 210 performance requirements.

NHTSA-2012-0036-0043 (FAD Testing on IC School Bus).

NHTSA-2012-0036-0042 (FAD Testing on Blue Bird School Bus).

NHTSA-2012-0036-0044 (FAD Testing on MCI Motorcoach).

V. Final Rule and Response to Comments

A. Force Application Device

The comments summarized in this section were to the NPRM unless otherwise noted.

1. FAD Design

i. Durability and Strength of FADs

The NPRM anticipated that the FAD would have a long service life because it consists of components (a polyurethane shell, aluminum structural components, and aluminum and steel peripheral attachments) that should not experience appreciable wear.

Comments

Daimler Trucks North America LLC (DTNA), the Truck and Engine Manufacturers Association (EMA), and the Alliance of Automobile Manufacturers (Alliance)

brought up concerns about the how durable the FAD would be if tested to failure. FMVSS No. 210 does not require testing the seat belt assembly anchorages to failure nor does the agency conduct tests to failure. However, these commenters noted that after ensuring compliance with the FMVSS No. 210 requirements manufacturers normally continue to load the anchorages to failure. EMA stated that testing to failure provides crucial data regarding the compliance margin and ultimate strength of the seat belt assembly anchorages. EMA's concern is that it is unknown whether the FADs are strong enough to withstand this testing and that if test engineers must, after proving compliance, replace the FAD with body blocks to test to failure, it would increase the cost and accuracy of testing. DTNA similarly stated that due to the lack of experience with the construction and durability of the FAD it is unknown whether it will withstand the destructive testing that manufacturers perform to evaluate the ultimate strength of the seat belt anchorages. The Alliance also stated it was concerned with the long-term durability of the polyurethane shell, especially given the lack of any data or analysis regarding the durability of this test device at the elevated loading conditions typical of original equipment manufacturer (OEM) compliance testing.

After NHTSA received comments from the Association of Global Automakers and the Alliance of Automobile Manufacturers, they merged to form the Alliance for Automotive Innovation.

Agency Response

The agency does not perform or require tests to failure for the seat belt assembly anchorages. While we understand manufacturer concerns, the agency is not willing to research the FAD's material strength for testing that goes beyond our performance requirements. While we have not found any evidence of wear on the FADs used for our research, we cannot predict if testing to failure with the FADs will result in a shorter service life than we predicted for our compliance test requirements, particularly since the failure level would vary for every anchorage design.

If the vehicle manufacturer is concerned about the durability of the FAD when testing anchorages to failure, the manufacturer has the option to certify compliance using the current body blocks.

ii. FAD Material and Potential Seat Belt Slippage

The FADs consist of an upper torso portion and a pelvic portion hinged together to form a single device. The

torso and pelvic portion are manufactured from a smooth polyurethane material. The lap belt would be positioned over the pelvic portion of the FAD, and if applicable, the shoulder belt would be positioned across the FAD's torso portion.

Comments

EMA, DTNA, the Alliance, Navistar, Inc. (Navistar), and the People's Republic of China were concerned about the potential for the FAD to allow the seat belt (or the material that is used to replace the seat belt) to slip during testing, resulting in an invalid test. EMA commented that while the current body blocks are covered with foam that secures the seat belt in place, the FADs are made of smooth polyurethane that may allow the belt to slip. The Alliance similarly stated that the FADs do not guide the webbing like the current body blocks. DTNA commented that the belt might slip in heavy truck testing due to the unique seating and seat belt systems (

e.g.,

air suspension seats have a more upright seating configuration and tethers to anchor the seat belts to the cab structure). Navistar was also concerned about the validity of the test if the torso belt slipped off the FAD.

Agency Response

The agency did not encounter any problems with the seat belts slipping off the FADs in any of the testing conducted, including indicant tests on fifteen light vehicles and three heavy vehicle driver seats. In fact, NHTSA did not observe any significant movement of the seat belt on the FAD during any tests, so we do not see this slippage as a potential source for seat belt webbing damage. If the seat belt slid off or over the FAD during a compliance test it would be considered an invalid test, not a non-compliance. The commenters provided no data to support their concerns for seat belt slippage when the FAD is used. Therefore, the agency does not anticipate that this slippage will be a problem in future compliance tests or testing manufacturers may conduct for self-certification.

iii. Weight of the FADs

The NPRM stated that the FAD1 weighs 55.79 kg (123 lb) and the FAD2 weighs 27.55 kg (47.5 lb). For comparison, the weight of the current body blocks varies depending on the material with which they are fabricated and the design of the torso body block. As noted earlier, the standard does not specify the type of material. NHTSA's understanding, based on its test experience, is that the torso body blocks can weigh approximately 7.7 kg (17 lb) to 13.6 kg (30 lb) depending on the design type (see discussion in section V.B.7.a) and material (aluminum and/or steel). The standard pelvic body block weighs approximately 37.9 kg (83.5 lb), and the optional pelvic body block for inboard seating positions weighs approximately 19.5 kg (43 lb), when made from aluminum.

Comments

Navistar, the Association of Global Automakers (Global), and Freedman Seating Company (FSC) commented that the increased weight of the FADs compared to the current body blocks could make it difficult to use. For example, Navistar commented that the FADs are significantly heavier than the current body blocks, so installing, positioning, and removing the FADs could cause some issues. FSC stated that it requires one person for every 50 lb to lift items, so three people would be required to lift the FAD1 in and out of the vehicle. FSC also stated that it is nearly impossible for a mechanical assistant to help position the FADs in a vehicle and that tight-quartered vehicles with four rear rows would probably be the most difficult platform to position the FADs. FSC also stated it was concerned about possible injuries (back injuries and strains from lifting) to lab technicians from positioning the FADs.

Agency Response

In its testing, NHTSA found that that the FAD was easier to use than the body blocks. For example, NHTSA found that the FADs generally require one installation attempt while the current body blocks may require multiple attempts, possibly with a technician holding the block as the preload is applied, because the torso block must maintain its position in the specified zone during preload. While we acknowledge that the FAD1 is heavier than the combined weight of the current body blocks, during NHTSA's testing it rarely took more than one technician to place the FAD1 in and out of the vehicle. NHTSA also did not encounter any problem with placing the FADs in tight-quartered vehicles, such as the third row of the Chevrolet Suburban and Chevy Express small bus. We acknowledge that test laboratories may have specific policies that prohibit one person from lifting a certain amount of weight, and that whether one technician could place the FAD in a seat would depend on the individual's strength, but we suspect that test laboratories encounter the same issue with anthropomorphic test device dummies, which are, in some cases, significantly heavier than the FAD1; for example, the Hybrid III (HIII) 50th male ATD weighs approximately 170 pounds.

iv. Dimensions of the FADs

The NPRM included a table that summarized the dimensions of the FAD1 and FAD2, and, for comparison, the dimensions of the HIII test dummies representing the 50th percentile adult male, 10-year-old child, and the 5th percentile adult female.

The FAD1's dimensions most closely resembled that of the 50th percentile adult male and the FAD2's dimensions were less than that of the 10-year-old child test dummy.

77 FR 19155, 19156 (March 30, 2012).

Comments

In response to the NPRM, Johnson Controls, Inc. (JCI) acknowledged the need to use the FAD2 for designated seating positions too narrow to accommodate the FAD1 but commented that the shoulder height for the FAD2 is exceptionally low, creating unrealistic load vectors that will negatively impact seating designs and configurations. JCI suggested that if the FAD2 is intended to replicate a small child, it should be seated in a child or booster seat to create real-world load vectors, and if it is intended to replicate a small adult that the agency should reference databases such as UMTRI to aid in the development of the test device.

In response to the SNPRM, an individual (Jung HoYoo) commented that t the safety of average female drivers and passengers would be better addressed by using another FAD that represents the 50th percentile adult female, because the FAD2 represents the weight/size of approximately half of a 50th percentile male.

Agency Response

NHTSA acknowledges that the placement of the seat belt may not be ideal for some seat belt configurations with the FAD2, but our research has not indicated that the use of the FAD2 is problematic or that it impacts the test results negatively. None of the research tests conducted with the FAD2 resulted in a test failure. For further discussion of the load vectors, see section V.A.4.

The FAD2 was developed to be used at designated seating positions that are too narrow to accommodate the FAD1, when multiple seating positions must be tested simultaneously, such as some inboard seats in the rear rows of passenger cars and MPVs. The FAD2 was not modeled after a particular Hybrid III ATD or occupant category (

e.g.,

50th percentile adult female) but rather a scaled-down FAD1 to fit narrow

designated seating positions. The NPRM explained that the FAD2's shoulder pivot height, shoulder breadth, and hip breadth is 60%, 71%, and 66% of the 50th percentile male's, respectively. Therefore, the individual commenter's concern that the FAD2 represents an occupant half the size of a 50th percentile male is inaccurate. The weight of the FADs cannot be used to infer representation of a particular Hybrid III ATD or occupant category because the FADs do not have lower legs, arms, or heads. The intent of FMVSS No. 210 is to assess the performance of the seat belt assembly anchorages, not to measure the forces imparted to a vehicle occupant in a crash, so test devices that represent a range of occupant sizes are not necessary.

If the vehicle manufacturer is concerned about the performance of the seat or seat belt assembly anchorages when tested with the FAD2, the manufacturer has the option to certify compliance using the current body blocks.

v. FAD Abdomen Area

The FAD developed by Karco was designed with a pelvic area consisting of a molded protrusion to facilitate placement of the lap belt; the protrusion is the polyurethane part between the aluminum structural pieces that connect the upper and lower portions of the FAD. NHTSA observed in early indicant testing during development of the FAD that the aluminum connecting pieces were causing damage to the belt webbing.

To prevent webbing damage, NHTSA developed hip clips. The hip clips evolved over several design iterations. The initial design version of the hip clips consisted of a metal piece that prevented the aluminum connecting pieces from damaging the seat belt webbing. However, in one of the agency's first indicant tests, the initial version of the hip clips damaged the belt, resulting in the belt breaking.

Accordingly, the agency redesigned the hip clips to have smoother edges to prevent belt breakage. A prototype version of the redesigned hip clips was installed in the FADs for the remainder of the agency's research tests; no belt damage was observed with the redesigned hip clips. The hip clip specifications docketed with the NPRM

differ slightly from the prototype version of the redesigned hip clips; the hip clips in the proposed drawing are angled to further prevent the seat belt from riding up and they specify stronger and bigger hardware for attachment.

FMVSS No. 207 Indicant Test, General Motors Corp., 2006 Chevrolet Express Bus, NHTSA No. C60100, pp 40-72. General Testing Laboratories, Inc. May 2, 2006 (Report No. 207-GTL-05-009).

NHTSA-2012-0036-0002; Drawings NVS221-210-16B (pg. 1016), NVS221-210-18-B (pg. 1017), NVS221-210-16J-B (pg. 1042), and NVS221-210-18J-B (pg. 1043).

Comments

The Alliance and JCI referenced an indicant test on the 2006 Chevrolet Express Bus in which the initial design version of the hip clips damaged the seat belt webbing. The Alliance commented that it was concerned that even with the redesigned hip clips the FAD's pelvic/torso intersection is not biofidelic and there is a risk of cutting the webbing which is non-representative of field performance. It also questioned whether the pivot point between the torso and pelvis is required. JCI similarly recommended redesigning the hip clip.

The People's Republic of China also commented on the potential for the FAD to damage the seat belt webbing.

JCI referred to the “contour abdomen plate,” which we construe as referring to the hip clips because JCI referenced a picture of the webbing damage caused by the hip clips in the 2006 Chevrolet Express Bus indicant test.

Agency Response

The redesigned hip clips are intended to prevent damage to the seat belt by improving the biofidelity of the pelvic/torso intersection to the extent possible. While it is not perfectly biofidelic, the nine research tests with the redesigned hip clips, docketed with the NPRM, and nine research tests conducted by the agency since the NPRM, have not shown damage to the webbing of the seat belt. However, we believe that the design of the prototype hip clip needed improvement, and accordingly modified the design presented in the proposal. We believe the redesigned hip clips function as intended. Regarding whether the existing pivot point between the torso and pelvis portions is necessary, the agency believes a pivot point is necessary to properly position the FAD in the seat. Different seat designs and seat contours will require the ability to pivot the torso and pelvis to properly position the FAD.

vi. Bridged Pull Yoke

The FAD consists of an upper torso portion and a pelvic portion hinged together to form a one-piece device. Where the force actuator attaches to the FAD depends on the seat belt type. For Type 2 seat belts, the force actuator is connected to separate connection points on the torso and pelvis portions of the FAD. For Type 1 seat belts, a bridged pull yoke is used to connect the connection points of the torso and lap portions of the FAD (so that they are jointly pulled) and the force actuator is connected to this pull yoke. The proposed regulatory text defined the “bridged pull yoke” as the yoke that bridges the torso and pelvis on the FAD1 or FAD2 to apply the required force to a Type 1 seat belt assembly.

Comments

The Alliance suggested the bridged pull yoke be redesigned to prevent it from digging into the seat cushion, which introduces an unintended load path into the system. It cited the indicant test with the 2005 Chrysler Town and Country Minivan as evidence.

FMVSS No. 207 Indicant Test, Daimler Chrysler Corporation, 2005 Chrysler Town and Country Minivan MPV, NHTSA No. C50310, p. 28. General Testing Laboratories, Inc. May 2, 2006 (Report No. 207-GTL-05-006), Figure 5.20, pg. 28.

Agency Response

The agency conducted four indicant tests (totaling six seating positions) with a FAD1 or FAD2 fitted with the bridged pull yoke on a Type 1 belt. To investigate the Alliance's concern, NHTSA re-examined these indicant tests. One was the indicant test cited by the Alliance with the 2005 Chrysler Town and Country Minivan, in which a third-row center seat with a Type 1 belt was tested with a FAD2 fitted with the bridged pull yoke.

The test photos do not clearly depict the interaction of the FAD2 and the seat cushion. (A video was not recorded for this test.) Therefore, NHTSA is unable to conclude whether the bridged pull yoke dug into the seat. A second test was the indicant test with the 2005 Ford F-150, in which a front inboard seat was tested with a FAD2 with a bridged pull yoke.

The pull yoke did not appear to dig into the seat in a way that would interfere with the test because it was near the edge of the seat cushion. To the extent that this circumstance did present an issue during a test, the pull angle or chain could potentially be adjusted to alleviate it. The third indicant test was on a 2000 MCI 102-EL3 Series Motorcoach in which a driver's seat was tested with a FAD1 with a bridged pull yoke.

The pull yoke did not appear to

dig into the seat. The fourth indicant test involved a 2006 Chevrolet Express Bus in which we tested an inboard seat in the third, fourth, and fifth rows with the bridged pull yoke on a FAD2.

The pull yoke did not appear to dig into the seat.

FMVSS No. 207 Indicant Test, Daimler Chrysler Corporation, 2005 Chrysler Town and Country Minivan MPV, NHTSA No. C50310, pg. 28. General Testing Laboratories, Inc. May 2, 2006 (Report No. 207-GTL-05-006).

FMVSS No. 207 Indicant Test, Ford Motor Co. 2005 Ford F-150 Pickup Truck, NHTSA No. C50210, pgs. 18-28.

Using New Force Application Device on Heavy Duty Vehicle Seats, Research Supporting FMVSS

No. 210 Rulemaking, pgs. 13-15. MGA Research Corp., Sept. 11, 2013 (Report No. .207/210-MGA-2013-001).

FMVSS No. 207 Indicant Test, General Motors Corp., 2006 Chevrolet Express Bus, NHTSA No. C60100, pgs. 40-72. General Testing Laboratories, Inc. May 2, 2006 (Report No. 207-GTL-05-009).

After considering the Alliance's concern, NHTSA has decided not to redesign the bridged pull yoke. With respect to the FAD2, we acknowledge that while the pelvic portion of the FAD1 usually extends to the front edge of the seat, the pelvis of the FAD2 is not as long as the pelvis of the FAD1. Therefore, the bridged pull yoke could possibly dig into the seat if the seat cushion is soft. However, the test report cited by the Alliance does not clearly show that this is the case. Moreover, none of the test reports noted this as an issue. We also note that even if it were to be an issue, it would not arise frequently because all rear DSPs under 10,000 pounds (except side-facing seats) are required to have Type 2 belts. In any case, if this is a concern for a manufacturer, it can certify to the body block compliance option. Therefore, the agency declines to implement a redesign of the bridged pull yoke.

vii. Clarifying Attachment to Force Actuator

The type of seat belt dictates where the force actuator attaches to the FAD. For Type 2 seat belts, the force actuator is connected to separate connection points on the torso and lap portions of the FAD. The actuator is connected to the torso via a torso pull yoke; specifically, the actuator is connected to the eye bolt attached to the pull bracket.

The actuator is connected to the pelvis via a through hole on the pelvis.

For Type 1 seat belts, the force actuator is connected to a bridged pull-yoke that is used to connect the attachment points of the torso and lap portions of the FAD (so that they are jointly pulled). The drawing package docketed with the NPRM included a single drawing labeled “FAD 2—Bridged Pull Yoke.” The bridged pull yoke is attached to the eye bolt and through hole of the FAD and the test load is applied to the second through hole on the bridged pull yoke.

Drawings NHTSA221-210-04 (FAD 1—TORSO PULL YOKE) and NHTSA221-210-04J (FAD 2—TORSO PULL YOKE).

Drawings NHTSA221-210-02 (FAD 1—BODY—PELVIS) and NHTSA221-210-02J (FAD 2—BODY—PELVIS).

The proposed regulatory text did not clearly identify where the actuator would be connected to the FAD. For Type 2 seat belts, the regulatory text specified that the test forces should be applied “to the yoke attached to the torso of the FAD1 or FAD2 and to the eyelet attached to the pelvis of the FAD1 or FAD2.” For Type 1 seat belts, the regulatory text stated that the forces should be applied “to the bridged pull yoke.”

Comments

EvoBus GmbH (EvoBus)

commented that either the regulatory text or the drawings should be revised to clearly identify where the forces are to be applied, and that the bridged pull yoke should be explicitly marked to ease the understanding and preparation of the test.

After receiving comments from EvoBus they became Daimler Buses GmbH.

Agency Response

NHTSA has modified the proposed regulatory text and drawings to make them clearer. The regulatory text has been modified to use the same part names used in the design drawings (

e.g.,

eye bolt). We also modified the bridged pull yoke drawing to clarify the attachment points for the torso, pelvis, and actuator. Because the same bridged pull yoke is used for the FAD 1 as is used for the FAD 2, we have added a drawing for the bridge pull yoke (NHTSA221-210-27) to the finalized drawing package for the FAD 1. There is a drawing (NHTSA221-210-27J) depicting the bridged pull yoke in the drawing package for the FAD2.

However, we are not specifying exactly how the actuator will be attached to these parts of the FAD because this piece of laboratory equipment could vary (

e.g.,

different chains or other material could be used to transfer the required load) depending, for example, on whether seat belt anchorage strength testing is performed to failure (as some commenters indicated they do) or testing just to FMVSS No. 210 performance requirements. This is consistent with the current specification of the body blocks in the standard, which also do not specify how the actuator is attached to the body blocks.

viii. Human Form Design

The NPRM stated that one of the advantages of the FAD is that it is more representative of the human form than the upper torso and pelvic body blocks. We also identified other advantages of the FAD over the body blocks. We noted that the FAD geometry does not put an unrealistic bending force on the belt buckle, and that the FAD does not have sharp edges, reducing the likelihood that the seat belt will break during testing. We also noted that the FAD does not result in as much seat belt spool-out as seen with the body blocks, thereby eliminating the problem of bottoming-out the hydraulic cylinders during the test, and that the FAD should be easier and quicker to position than the body block, potentially decreasing test costs.

Comments

EMA, DTNA, and an individual commenter to the SNPRM (Jung Ho Yoo) commented that the NPRM did not justify why the human form design would be an advantage for compliance testing. EMA stated that the scope of FMVSS No. 210 only includes seat belt anchorages and that the seat belts that contact vehicle occupants are regulated by FMVSS No. 209, “Seat belt assemblies,”

and that because the anchorage strength test does not require use of the seat belt, any potential advantages related to belt breakage may not be relevant. EMA also stated that NHTSA failed to explain why the FAD transfers test loads any more effectively than the body blocks. DTNA similarly commented that resemblance to the human form may not be relevant when testing strength of seat belt anchorages which do not come into contact with occupants.

EMA referenced FMVSS No. 208, but we understand it to have meant FMVSS No. 209.

Agency Response

NHTSA agrees that the NPRM was not clear on this point. We clarify that we believe that the human form design is advantageous in that its more realistic features decrease the risk of problematic interactions between the test device and the belt/vehicle. We also note that the human form of the FADs could allow for testing of future seat belt designs with unconventional seat belt geometries (such as four-point and five-point seat belts) that cannot be accommodated by the current body blocks. Primarily, however, we believe that the advantages of the FAD will be related to ease and repeatability of testing. The agency believes that the FAD resolves many existing test-related issues with the body blocks. The docketed test reports note several advantages of the FAD. It does not put an unrealistic bending force on the belt buckle, unlike the pelvic body block. The FAD lacks the sharp edges of the pelvic body block,

which reduces the likelihood of the seat belt buckle or webbing material (or the material used to replace the seat belt webbing during testing) breaking during testing. In addition, the current body blocks move independently of each other, and the agency's test laboratories have indicated that sometimes the increased range of motion associated with the torso body block can be problematic (

e.g.,

the hydraulic cylinders used to pull the belts can reach the end of their stroke). As EMA noted, FMVSS No. 210 does not require testing with the vehicle's seat belt. Therefore, a shorter substitute belt or cable could be used to solve the problem of reaching the end of the stroke of the loading devices. Using a shorter substitute belt or cable also alleviates the problem with seat belt buckle breakage. However, for simplicity, the agency prefers conducting the compliance testing, if possible, with the vehicle's original seat belt assembly. Other benefits of the FADs are discussed elsewhere in this document.

ix. Effect on Seat Back Deformation

The NPRM did not specifically address whether there was the potential for the FAD to interact with the seat structure in a way that could affect test outcomes.

Comments

TÜV Rheinland Kraftfahrt GmbH (TUEV) and JCI had concerns related to seat structure deformation. TUEV commented that the FAD could reinforce the seat structure during tests of integrated seats (seats with seat belts that attach to the seat), which is not representative of the deformation that would occur in a real accident and could potentially lead to different results than testing with the body blocks (

i.e.,

where the anchorages would fail when tested with the body blocks, but pass when tested with the FAD). JCI stated that the FAD structure could interfere with the manufacturer's testing protocols that are intended to gauge backrest deformation.

Agency Response

The agency's research tests demonstrate that the FAD pulls away from the seat back during testing and does not reinforce the seat structure. In fact, the FAD would more accurately represent the dynamics of an occupant in a real crash event because of its geometry: it hinges at the H-point and it is not two independent blocks. TUEV and JCI did not provide any supporting information on the protocols they used for gauging backrest (seat back) deformation with the FAD versus the body blocks, which limits our ability to respond in more detail to this concern.

x. Missing Tolerance Values

The drawing packages for the FAD1 and the FAD2 were docketed in conjunction with the NPRM. In the NPRM, we stated that the drawing packages were sufficiently detailed to allow manufacturers to fabricate the FAD1 and FAD2.

Comments

JCI commented that the drawing packages are incomplete due to the lack of tolerance designations in numerous places. They suggest that this incomplete information be remedied before finalizing the FAD.

Agency Response

NHTSA has added tolerances to all dimensions specified in the finalized drawing package. If a tolerance is not indicated next to a specified dimension, an overall tolerance summary is specified at the bottom of the drawing page.

xi. Design Drawings and Supplemental 3-D Data

NHTSA docketed the FAD design drawings with the NPRM. The proposed regulatory text incorporated these design drawings by reference. The agency was unable to docket the computer-aided design (CAD) files of the FAD drawings or three-dimensional data because the docket does not accept CAD files. In the past NHTSA has generally not incorporated by reference 3-D CAD data for FMVSS documentation or Part 572 anthropomorphic test devices, although it has not infrequently made 3-D geometric rendering solid models available to the public for reference purposes.

See, e.g.,

77 FR 11651 (Feb. 27, 2012) (final rule for Hybrid III 10-year-old child test dummy) (“[T]hree-dimensional engineering aids are available from the NHTSA website for complex dummy part dimensions. While these aids are not part of this specification, they can be used by the public for reference purposes.”).

Comments

Both American Honda Motor Co., Inc. (Honda) and the Alliance suggested in their comments that the 3-D drawing data for the FAD1 and FAD2 be made readily available. Honda stated that the 3-D drawings were necessary to allow manufacturers to fully assess the proposed test procedures and detect potential issues that would need to be addressed before it is finalized. The Alliance commented that provision of the 3-D CAD data could reduce the cost and lead-time associated with the procurement of the FADs.

Agency Response

During the NPRM comment period the agency provided 3-D solid models of the torso and pelvis portions of the FADs to entities that requested them in response to the NPRM. A memo was filed in the docket documenting the requests and agency response.

In the memos, the agency additionally stated that it would provide the files to others upon request. We received requests from, and provided the files to, MGA Research Corp., Faurecia, General Motors, RCO Technologies, Jasti-Utama, Inc., and SCHAP Specialty Machine.

NHTSA-2012-0036-0003, NHTSA-2012-0036-0020.

We believe that the drawing package is sufficiently detailed to allow manufacturers to fabricate the FAD1 and FAD2. During development of the NPRM, NHTSA compared a FAD1 and FAD2 manufactured by Denton ATD using the drawing package to a FAD1 and a FAD2 that pre-existed the drawing package.

Based upon this inspection, the agency determined that the devices were sufficiently equivalent.

A document describing the inspection criteria used to make this determination has been placed in the docket for the NPRM.

In addition to the two-dimensional engineering drawings being incorporated by reference in the final rule, NHTSA is providing, as supplemental documentation, 3-D solid models. NHTSA has regenerated these 3-D geometric renderings by scanning our physical FADs. These supplemental reference materials are summarized in Table 3. These files are not being incorporated by reference into 49 CFR 571.5 and are therefore will not be part of the FAD specification. Instead, they are intended only for reference purposes (

e.g.,

to facilitate fabrication). The files are available via NHTSA's FTP site.

A memo to this effect is also being placed in the docket for this final rule.

https://www.nhtsa.gov/file-downloads?p=nhtsa/downloads/.

We note that some minor changes have been made to the proposed drawings. Some dimensions on NHTSA221-210-02 and 03 (FAD 1 Body Torso and FAD 1 Body Pelvis) and NHTSA221-210-02J and 03J (FAD 2 Body Torso and FAD 2 Body Pelvis) have been modified slightly to match the dimensions of the scanned 3-D solid models. The revised dimensions are related to the molded portions of the FADs. The hip clip drawings were also modified to match the redesigned hip clips that are installed on the FADs at

NHTSA's Vehicle Research Test Center (VRTC).

Table 3—Design Reference Documentation

Title

Link

FAD Drawing Package

https://www.nhtsa.gov/file-downloads?p=nhtsa/downloads/Seat-Belt-Assembly-Anchorages/FAD-Drawing-Package-April-2024.zip.

FAD Drawing Package—2D AutoCAD

https://www.nhtsa.gov/file-downloads?p=nhtsa/downloads/Seat-Belt-Assembly-Anchorages/FAD-AutoCAD-DWG-Files.zip.

FAD Drawing Package—3D Inventor Format

https://www.nhtsa.gov/file-downloadsp=nhtsa/downloads/Seat-Belt-Assembly-Anchorages/FAD-Inventor-Files.zip.

FAD Drawing Package—3D STEP Format

https://www.nhtsa.gov/file-downloadsp=nhtsa/downloads/Seat-Belt-Assembly-Anchorages/FAD-3D-STEP-Files.zip.

2. FAD Test Procedure

i. Positioning Procedure

The proposed regulatory text specified how to adjust the seat and position the FAD at the outset of the strength test. The proposed regulatory text specified that the seat back would be placed at the manufacturer's design seat back angle (as measured by SAE J826 (July 1995) with the seat in its rearmost and lowest position). The NPRM essentially proposed that the FAD be placed so that its midsagittal plane is vertical and aligned with the center of the seat. Although the term “Midsagittal plane” was not defined in the proposed regulatory text, it is defined in FMVSS No. 208 S16.3.1.3 as “the vertical plane that separates the dummy into equal left and right halves.” The proposed regulatory text defined and used two different terms to refer to the center of the seat: “longitudinal centerline of a forward and rear-facing seat” and “seat centerline.” Both were defined with reference to the SgRP, and both essentially referred to the center of the seat.

Comments

The Alliance questioned how the FADs should be placed in the seat if the seat centerline does not align with the SgRP. It also asked how the FAD should be placed in a seat with multiple designated seating positions when the lateral seat width is not equally designated by design.

Agency Response

We first note that the NPRM inadvertently used two different terms, “longitudinal centerline” and “seat centerline,” to refer to the same concept. The final rule clarifies this discrepancy by using a new term, “seat reference plane,” which is defined as “the vertical plane that passes through the SgRP (as defined at 49 CFR 571.3) and is parallel to the direction that the seat faces.” This is essentially the same procedure NHTSA intended to specify in the NPRM—namely, positioning the FAD so that the midsagittal plane is aligned with the vertical plane passing through the SgRP in the same direction the seat faces. We decided to use the SgRP and not the H-point for consistency with the proposed body block test procedure. Both Alliance's concerns are addressed by this definition because the SgRP does not depend on either the seat centerline or width. The final rule also adds a definition of “midsagittal plane” specific to the FAD because the definition of it in FMVSS No. 208 refers to a test “dummy.”

We also note that the final rule modifies the proposed seat adjustment. In the NPRM, the agency proposed a seating procedure for the FAD that specified, in addition to placing the seat at the rearmost position, the seat back would be adjusted to the manufacturer's design angle and the seat to its lowest position. Now that the agency is reinstating the option to test with the body blocks (with a refined test procedure), we are making the seat adjustment provisions consistent with the manufacturer's SgRP, since the body block zones use the SgRP as the reference point. Specifically, we are adding regulatory text to clarify that the seat is to be adjusted to the rearmost normal riding or driving position, to make the H-point position consistent with the SgRP. The rearmost normal riding or driving position is specified by the manufacturer and includes all modes of seat adjustment, including horizontal, vertical, seat back angle, and seat cushion angle.

To this end, we have added a specific regulatory text section on seat adjustment that applies to both the FAD and body blocks. We note that in the NPRM, the seat was proposed to be placed in its rearmost and lowest position when using the FAD, but no details were provided as to how such a position would be achieved. By specifying a seat position consistent with the SgRP, the agency is fully articulating a well-defined seat position with which all manufacturers should be familiar. This information is typically already requested prior to testing by OVSC.

ii. Selections of FAD1 or FAD2 and Contact Between Adjacent FADs and Vehicle Interior

The NPRM proposed an iterative procedure for determining which FAD NHTSA would use when simultaneously testing the seat belt assembly anchorages of adjacent seats. Specifically, the NPRM specified positioning FAD1s on each seat, and if, “prior to conducting the test, there is contact between the FAD1s, or if FAD1s cannot be positioned side-by-side due to contact, replace an inboard FAD1 with a FAD2.”

This would not have disallowed contact once the test had started (

i.e.,

once the test force had begun to be applied). However, because the proposal simply specified that contact was not allowed “prior to conducting the test,” it was not clear whether this applied before and/or after the preload force was applied to the FADs. The proposal also did not disallow (or specify any procedures with respect to) contact between FADs and the vehicle interior. Finally, the proposal did not contemplate novel seating configuration or vehicles without a driver's designated seating position.

S5.3(a) (proposed).

Comments

Honda requested clarification on whether contact between FADs during testing is allowed. Honda also requested clarification on whether contact between the FAD and the vehicle interior would affect the selection, replacement, or seating procedure of the FAD. FSC similarly questioned what constituted “contact,” and whether this term referred to any part of any FAD touching another FAD, or whether

contact between the FADs is permitted so long as it did not interfere with their functionality or independent operation. FSC also inquired about the possibility of changing the size of the FAD1.

Agency Response

The agency would not allow adjacent FADs to contact each other at all at the onset of testing,

i.e.,

when the FADs have been positioned, but prior to the preload being applied. The hierarchical procedure used to determine which FAD to place in each seat if contact occurs during placement should provide ample room to eliminate contact during testing of the anchorages. However, although not expressly addressed in the regulatory text, contact between adjacent FADs once test preloads have begun is not prohibited. Although we believe incidental contact of the FADs during preload and loading is unlikely, we believe if it does occur the contact will not unduly influence the results and will not invalidate the test. Additionally, if a manufacturer is concerned about such incidental contact, it can choose to test with the body blocks.

As far as contact with the vehicle interior, the agency normally conducts the FMVSS No. 210 compliance tests with the vehicle doors removed so we do not encounter contact with the vehicle interior in our tests of outboard seats next to a door. For outboard seats that are not positioned next to a door, contact may also be found permissible if it does not interfere with the loading of the anchorages and attaining the required load value. Since this determination should be made on a case-by-case basis, and to avoid limiting the agency's testing options due to inconsequential contact of the FAD with the vehicle interior, the regulatory text will not address this determination of permissible contact with the vehicle interior. This aspect of the test procedure may be addressed in the laboratory test procedure for FMVSS No. 210.

The agency declines to change the size of the FAD1. The size of the FAD1 did not present any problems in the testing the agency conducted in support of this rulemaking. In any case, if a DSP is too narrow to accommodate the FAD1, the smaller FAD2 may be used. If, on a seat with multiple DSPs, each DSP is occupied by a FAD2, we believe there is minimal potential for contact at preload because the width of the FAD2 at its widest point (the shoulder width) is 11.78 ± .05 in (299.2 mm ± 1.27 mm); based on NHTSA's experience with testing and knowledge of the vehicle market, this is less than the width of many or most DSPs. A DSP less than a foot in width would be exceedingly small, and smaller than the minimum required width for a DSP.

The minimum DSP width (for most vehicles with a GVWR less than or equal to 10,000 lb) is 330 mm (13 inches).

See

571.3 and 571.10.

Finally, with respect to the iterative procedure proposed to determine if the FAD1 or FAD2 would be used in a particular seat, consideration was not given at the time of the NPRM to the potential for novel seating configurations and vehicles without a driver's designated seating position. For forward and rearward facing seats, the final rule maintains the same overall hierarchy of prioritizing inboard seats for the use of the FAD2, to eliminate contact between FADs in adjacent seats. However, the reference to driver's side versus passenger side has been replaced by right-hand side versus left-hand side, as viewed from the direction of the seat. Additional regulatory text has been added to address non-forward and non-rearward facing seats.

iii. Use of FAD2 on Buses and Heavy-Duty Trucks

As previously discussed, NHTSA developed the FAD2 for use at DSPs too narrow to accommodate the FAD1, although in the proposed seating procedure NHTSA would first attempt to position FAD1s in all seats.

Comments

EvoBus commented that when testing buses, it would be preferable to specify use of the FAD2 for double seats because in coaches the situation regarding shoulder width is similar to the shoulder width in the rear seats of passenger cars.

FSC noted that its standard passenger bus seat width is 17.75 inches (45.085 cm), which is the same width as the FAD1. Based on the proposed seating procedure, FSC commented that most of its DSPs would require a FAD1 to be replaced by the FAD2 in the outboard DSP to avoid contact. Based on this concern, FSC questioned if it was possible to change the size of the FAD1.

Navistar expressed concern regarding the potential effect on the test results if a FAD1 is replaced with a FAD2, because it could differ from what was used when testing with the current body blocks (larger pelvic block vs. smaller pelvic block) for a given seat. Navistar believes if this were the case, it would result in the need to identify these testing differences for each seating position and revalidation of these vehicles, and potentially some redesign or reengineering if this testing difference changes the test results.

Agency Response

The agency declines to accept the recommended changes. NHTSA does not agree with the need to limit the testing of bus seats with multiple DSPs to testing solely with the FAD2, as suggested by EvoBus. There is no regulatory limit on bus seat width, so certain bus seat designs may allow for simultaneous testing with the FAD1 and FAD2 seated adjacent to each other. Therefore, rather than limit these bus seats to testing solely with the FAD2, the agency prefers an objective protocol for determining when to replace a FAD1 with a FAD2. We also decline to change the size of the FAD1 because the need for a smaller test device is met by the specification and use of the FAD2. In response to Navistar's comment, there is no indication that testing results differ depending on which FAD is used; NHTSA tested both sizes of the FAD in various light vehicles, and there were no test failures with either. With respect to heavy duty vehicles, NHTSA only tested with the FAD1, although the FAD2 was tested in a Chevrolet Express Bus, which, with a GVWR of 9,600 lb, is nearly into the heavy vehicle category. None of these tests resulted in failures. In addition, design margins should be sufficient to accommodate slight differences in force vectors between the FAD1 and FAD2. Nonetheless, if heavy duty manufacturers have vehicles for which the FAD1 does not fit under our test procedure, and they do not feel comfortable certifying with the FAD2, they may continue to use the body blocks.

iv. Bottoming Out of Hydraulic Cylinders

Test laboratories typically use hydraulic cylinders to achieve the required pull force. The NPRM stated that the FAD would eliminate the problem of bottoming out of the hydraulic cylinders that sometimes occurs when performing the anchorage strength test using the current body blocks.

Comments

EMA commented that the FAD may make hydraulic cylinders more likely to bottom out during testing of medium- and heavy-duty vehicles because the FAD may cause more hydraulic cylinder travel to take up the slack necessary to apply loads to the anchorages for suspension seats and seat belt assemblies using tethers.

Agency Response

When the NPRM was published, NHTSA had not conducted any indicant tests with the FAD on heavy vehicles. The agency has since conducted FAD testing on two air suspension seats (one school bus driver's seat with a Type 2 seat belt and one motorcoach bus driver's seat with a Type 1 seat belt). In those tests, there was no indication that the FAD introduces more slack than the current body blocks. Based on observations during testing, the cylinders did not undergo additional travel and bottoming out of the hydraulic cylinders did not occur. The agency believes that the increased range of motion of the current body blocks is greater than the FAD and would more likely result in the hydraulic cylinders reaching the end of their stroke than with the FAD.

3. Repeatability

NHTSA assessed the repeatability of the FAD in two different ways. First, Karco assessed the consistency of the FAD seating procedure. Different test technicians positioned the FAD1 multiple times in nine different vehicles (ranging from two-seat sports cars to light duty trucks).

The technicians were provided a written copy of the seating procedure and no additional instructions. Once each technician had seated a FAD in a test vehicle, a Faro Arm (an articulated measuring arm with six degrees of freedom) was used to record the precise location of seven points on the FAD. Second, NHTSA evaluated the repeatability of the forces applied to the anchors using the FAD1.

We conducted four anchorage strength tests, using a rigid test seat in a test rig, with load cells located at the seat belt anchorages and a few other locations (

e.g.,

to measure the tensile load for the shoulder belt webbing). In each test, the FAD1 was positioned, belted, and pulled per the proposed test procedure. (NHTSA used the FAD1 for these repeatability evaluations; it has no reason to believe that similar results would not be achieved with the FAD2.)

“Final Report: Development of a Combination Upper Torso and Pelvic Body Block for FMVSS 210 Test, Revision A,” May 22, 2003, KARCO Engineering, LLC, pgs. 10, 13, 29 (NHTSA-2012-0036-0002).

“Repeatability Analysis of the Forces Applied to Safety Belt Anchors Using the Force Application Device” (DOT HS 811 139) (NHTSA-2012-0036-0002, pp. 977-995).

Comments

The Alliance commented that the repeatability analysis using a rigid test seat looks reasonably acceptable.

JCI commented that the FAD improves repeatability and reduces the potential for interference between the lap and torso blocks.

NHTSA understands this comment to refer to NHTSA's repeatability analysis

supra,

n. 66. The KARCO report also contains a repeatability analysis of the forces applied to the anchorages (NHTSA-2012-0036-0002, pp. 12-33).

See supra

note 30.

Agency Response

NHTSA concludes that use of the FADs leads to sufficiently repeatable results. Below we briefly summarize the results of NHTSA's testing. More information, including details on the methodology and results, is available in the cited reports in the rulemaking docket.

With respect to the consistency of the seating procedure, of the twenty-seven positionings of the FAD (three technicians × 9 vehicles), the average variance for positioning the FAD was less than

1/4

inch. We believe that this variability in seating the FAD is acceptable. In comparison, FMVSS No. 208, “Occupant crash protection,” at S10.4.2.1, specifies a 12.7 mm (

1/2

inch) tolerance for the H-point.

Accordingly, variability of less than

1/4

inch in seating the FAD is well within the same range of tolerance as specified in FMVSS No. 208 for positioning the H-point. This result is even more compelling considering that the technicians performing the FAD test were unaccustomed to the seating procedure, and that the results were based on a comparison of three points of the FAD surface, not just one point.

H-point means the mechanically hinged hip point of a manikin which simulates the actual pivot center of the human torso and thigh.

NHTSA also concludes that the forces applied to the seat belt anchorages using the FAD are repeatable (over repeated trials on the same seat and vehicle body design). To evaluate the repeatability of the forces applied to the anchorages, NHTSA used three different methodologies: the coefficient of variation, a general linear model, and a mixed model. Each of these analyses indicated that the test device applied loads to the anchorages in a repeatable manner. For example, the coefficient of variation analysis showed that the test procedure was repeatable, with all data channels except two rated “excellent.” Of the remaining two, one data channel was rated “good”, and another was rated “acceptable.” The “acceptable” data channel (retractor Y-axis) had a large measurement error relative to the other channels as seen by the “acceptable” coefficient of variation. However, the scale of the mean value, around 890 N (200 lb), is relatively small compared to the 13,345 N (3,000 lb) belt load, so the relatively larger measurement error has a minor effect on the overall test results. The general linear model and the mixed model similarly indicated that the forces measured from the 16 channels tend to be consistent and repeatable over time, and there are no statistically significant differences across tests.

4. Equivalence With the Body Blocks

In the NPRM, NHTSA stated that it believed use of the FADs would not affect the stringency of the strength test and would not affect the likelihood of a vehicle meeting or not meeting the standard's strength requirements. NHTSA reported the results of its indicant testing showing vehicles that met the anchorage strength requirements using the body blocks also met those strength requirements using the FAD.

See

NPRM at pgs. 19157-58 and section IV.

Comments

Commenters expressed concerns regarding whether the proposed FAD would perform equivalently to the existing body blocks. Comments from manufacturers and suppliers of heavy-duty vehicles focused on whether the FAD would perform equivalently in heavy-duty applications.

Several medium- to heavy-duty vehicle manufacturers, associations, and their suppliers commented in response to the NPRM on the lack of testing in these vehicles. They pointed out differences between heavy and light-duty vehicles and questioned whether heavy-duty vehicles would remain compliant if tested with the FAD.

DTNA, Navistar, and EMA commented on the unique characteristics of heavy-duty vehicles and seating systems and noted that NHTSA's testing did not include heavy-duty vehicles. For example, EMA stated there was no data indicating that existing seat belt assembly anchorages in heavy trucks would remain compliant if the FAD is used, and pointed out that heavy-duty vehicles have different seating and seat belt assembly systems than light-duty vehicles, citing the use of larger cabs, upright seating configurations, unique seat belt systems and anchorages, and air suspension seats (which utilize tethers to connect the seat belt assembly to the anchorages). EMA further commented (on the 2018 notice of availability) that the additional technical reports NHTSA docketed did not alleviate its concerns because they

did not contain any data with respect to the feasibility of the FAD on the medium- and heavy-duty trucks built by its member companies, and suggested that they did not address the unique aspects of the broad range of heavy-duty vehicles such as regional or line-haul tractors, refuse trucks, construction trucks, parcel delivery step vans, or many other applications that would be affected. EMA stated that if NHTSA proceeds with amending FMVSS No. 210 based only on the existing rulemaking record, it must exempt vehicles with a GVWR greater than 10,000 pounds from the new requirements. Navistar similarly stated that NHTSA's testing did not apply to its highly customized vehicles (

e.g.,

a wide variety of seating types and locations).

EMA, Navistar, and Hino Motors, Ltd. (Hino) commented that replacing the current body blocks with the FAD would impact the levels and/or directions of the forces that are applied to heavy truck seat belt assembly anchorages during compliance testing. For example, DTNA stated that it was unclear whether the FAD would introduce unique seat loads and seat belt loads not observed in testing with the body blocks in heavy-duty applications.

Commenters also questioned the equivalence of the FAD that were not limited to a specific vehicle type. The Association of Global Automakers (Global) commented that the results of the nine indicant tests reported in the NPRM do not provide a sufficient basis for using the current and proposed test devices interchangeably. JCI commented that more robust comparison testing should be conducted because the testing conducted on bench seats using the FAD and the current body blocks simultaneously on the outboard seats may not accurately represent the performance of the seat belt assembly anchorages when the adjacent designated seating positions are tested simultaneously with the same test device. Global noted that the NPRM identifies several aspects (

e.g.,

seat belt angle, spool-out, and placement) in which testing with the FAD differs from testing with the body blocks and stated that it is possible that such differences could affect test results. JCI commented that the testing NHTSA conducted does not cover the full range of seating structures and test conditions in use, and the FAD may interact with the seating configurations in a way that impacts seating and/or seat belt assemblies. JCI also stated that the FAD allows for more movement in the upper torso than the current body blocks resulting in a different vector of force on the seat structure and potentially also on the anchorages. The Alliance commented that there can be significant differences in the anchorage loads between the FAD and the current body blocks and that vehicle seats showed significant variability in the anchorage loads for some tests. The Alliance pointed to the agency's comparison tests of the 1996 Ford Taurus outboard lap anchorage in which the loads obtained using the FAD averaged 31% lower than the average of the loads obtained using the existing body blocks. Likewise, the comparison tests on the 2003 Honda Pilot, indicated a similar variability of 37%. The Alliance stated that even though the loads recorded in these cases were lower for the FAD, the level of variation

was troubling and needs to be examined further.

The agency understands this variation to refer not to variability among the measured loads from the FAD (discussed below in section V.A.3, Repeatability), but instead to refer to a comparison of the anchorage loads observed with the FAD and the anchorage loads observed with the body blocks.

Agency Response

The agency recognizes that at the time the NPRM was published, it had not conducted any indicant tests with the FAD on heavy vehicles. However, in response to comments on the NPRM, NHTSA subsequently performed three indicant tests with the FAD on the driver's seats in three different heavy-duty buses. The anchorages of all three seats met the FMVSS No. 210 anchorage strength requirements.

believe that we have conducted sufficient testing of the FAD in heavy-duty vehicles to conclude, with a reasonable degree of confidence, that the FAD is equivalently stringent to the existing body blocks in these vehicles. Three FAD tests were performed on seats in buses with a GVWR >10,000 lb (two school bus driver's seats, a pedestal-type seat and air suspension seat, and a motorcoach driver's air suspension seat). The school bus seats were both equipped with Type 2 seat belts and the motorcoach seat was equipped with a Type 1 seat belt. The anchorages of all three seat belts met the FMVSS No. 210 performance requirements when tested with the FAD. Some of the tested seat types are similar to those found in heavy-duty trucks (

e.g.,

air suspension, pedestal type seats), and the use of the FAD test device did not affect the compliance of the seat belt assembly anchorages. These results are also summarized in section IV.B and in Table 4. The evidence from the agency's testing program shows that heavy vehicles certified to FMVSS No. 210 strength requirements with the body blocks are still compliant when tested with the FAD. We have no data to support that the use of the FAD would affect the compliance of a vehicle.

The number in parentheses indicates the number of DSPs tested with that test device.

Table 4—Indicant Anchorage Strength Tests To Evaluate FAD Equivalence

Vehicle

Vehicle type

Test device(s)

Result

Research Docketed with the NPRM

2005 VW Passat

Light

Body Blocks (2)

FAD 1 (2)

FAD 2 (1)

Pass.

2005 Acura RL

Light

Body Blocks (2)

FAD 1 (2)

FAD 2 (1)

Pass.

2005 Toyota Avalon

Light

Body Blocks (2)

FAD 1 (2)

FAD 2 (1)

Pass.

2005 Buick Lacrosse

Light

Body Blocks (2)

FAD 1 (2)

FAD 2 (1)

Pass.

2005 Chrysler 300

Light

Body Blocks (2)

FAD 1 (2)

FAD 2 (1)

Pass.

2005 Chevy Express Small Bus

Light

Body Blocks (6)

FAD 1 (5)

FAD 2 (4)

Pass.

2005 Chrysler Town and Country Minivan

Light

Body Blocks (3)

FAD 1 (3)

FAD 2 (1)

Pass.

2005 Ford F-150 Super Crew Cab Pick-up

Light

Body Blocks (2)

FAD 1 (2)

FAD 2 (2)

Pass.

2005 Chevy Aveo

Light

Body Blocks (2)

FAD 1 (2)

FAD 2 (1)

Pass.

Research Docketed After the NPRM

2000 MCI 102-EL3 Series Motorcoach

Heavy

FAD 1 (1)

Pass.

2012 Blue Bird All American D3 RE School Bus

Heavy

FAD 1 (1)

Pass.

2012 IC CE School Bus

Heavy

FAD 1 (1)

No test.

2012 Honda Fit

Light

Body Blocks (1)

FAD 1 (1)

Pass.

2012 Mitsubishi I-Miev

Light

Body Blocks (1)

FAD 1 (1)

Pass.

2012 Chevrolet Suburban

Light

Body Blocks (2)

FAD 1 (2)

Pass.

2013 Ford Fusion

Light

Body Blocks (3)

Pass.

2013 Ford Fusion

Light

FAD 1 (2)

FAD 2 (1)

Pass.

2013 Ford C-Max

Light

Body Blocks (3)

Pass.

2013 Ford C-Max

Light

FAD 1 (2)

FAD 2 (1)

Pass.

2012 Subaru Impreza

Light

Body Blocks (3)

Pass.

2012 Subaru Impreza

Light

FAD 1 (2)

FAD 2 (1)

Pass.

In response to commenters who expressed concerns that the FADs would introduce different load vectors or that the test load would be distributed differently among the anchors compared to the body blocks in heavy and/or light-duty applications, we acknowledge that given the geometry and construction of the FAD it will not apply the test forces to the seat belt assembly anchorages in exactly the same way as the current body blocks. The load data in the KARCO report does show that the FAD distributes the test loads somewhat differently than the body blocks. On average, the FAD produced lower forces at the outboard shoulder and d-ring and higher forces at the outboard lap belt anchorage. These differences can be attributed to the differences in geometry and range of motion of the two test devices. Because the FAD has two pieces connected in a manner that restricts their relative articulation and the current body blocks move independently of each other, the range of motion of the devices is inherently different. In addition, the torso body block is supported in air by the torso portion of the seat belt; thus, the force vectors and load distributions on the shoulder belt portion will differ from those with the FAD. (For these reasons we also disagree with JCI's comment that the FAD allows for more movement in the upper torso.) However, while the force vectors or load distribution between the two test devices may not be the same, the total load on the seat belt assembly anchorages is the same for both the FAD and the body blocks. Moreover, as discussed in more detail below, the indicant test data shows that the FAD performs equivalently to the body block.

To respond to Global's comment that the 9 indicant tests docketed with and discussed in the NPRM are not sufficient to establish the equivalency of the FAD, and JCI's comment that this testing did not cover a full range of seating structures, NHTSA conducted additional testing with the FAD on passenger vehicles (as well as the additional heavy-duty testing discussed above) to allow for a more robust evaluation of the FAD1 and FAD2 with different seat belt assembly configurations. This additional testing included five passenger cars and a large SUV. In total ten different vehicle makes were represented in these tests and the earlier nine indicant tests. Therefore, we believe our testing with the FAD has been reasonably representative of the population of seats in light vehicles. To address JCI's comment that the original indicant tests were not conducted as an actual compliance test would be (because they mixed both the FAD and the body blocks), in this additional testing we tested three matched pairs of vehicles. One vehicle in each pair was tested with only the body blocks, and the other vehicle in the pair was tested with only the FAD.

There were no test failures in any of these additional indicant tests. All the indicant tests involving the FAD are summarized in section IV.B and in Table 4.

The testing was conducted on rear seats and the comparison vehicles were the same vehicle model and model year but with different battery options (

e.g.,

Ford Fusion Hybrid and Ford Fusion Energi).

NHTSA performed testing in a variety of vehicles—both light- and heavy-duty—to evaluate equivalence. We did not record failures in any of these tests. These results suggest to us that any

differences in test performance related to use of the FAD—such as differences in load vectors, seat belt angle, spool out, or interaction with the seating configuration—do not meaningfully affect the test results, and, most importantly, do not affect the ultimate test outcome. In addition, in real life, the seat belts and anchorages must accommodate occupants of varying sizes, sitting in a variety of sitting and seat positions; design margins for existing seating and restraint systems should be sufficient to accommodate this variation, which should also be sufficient to compensate for any effects due to differences in test performance related to the FAD.

The adequacy of existing design margins is supported by the history of NHTSA's anchorage strength compliance testing program. In the agency's forty-plus year history of testing for compliance with the anchorage strength requirements, test failures have been uncommon. According to the agency's records, for testing from 1972 to the present there were 327 compliance tests for FMVSS No. 210 and only 23 test failures.

The agency concludes that this testing is sufficient to establish, to a reasonable degree of confidence, that the FAD performs equivalently to the body blocks. Moreover, we are also retaining the existing body blocks and providing manufacturers the ability to choose the device to which they will certify compliance.

Based on a search of NHTSA's electronic records. This tally includes failures relating to any of the FMVSS No. 210 requirements, as well as what the agency would typically consider “non-tests” (

i.e.,

tests that could not be completed due to equipment or testing issues), so the number of actual test failures for the anchorage strength requirements is likely lower than this.

Furthermore, any concern about testing with the FAD resulting in different test outcomes than testing with the body blocks is obviated by the fact that the final rule provides manufacturers the choice of compliance options. In any case, as we explain here, after much testing, we have no evidence that the FAD results in different test outcomes.

5. Stakeholder Familiarity With the FAD

At the time of the NPRM, manufacturers and other stakeholders did not have access to the FAD for evaluation because the agency had possession of the only FADs in existence. The agency docketed the FAD design drawings with the NPRM.

See

NHTSA-2012-0036-0002, “Final Report: Development of a Combination Upper Torso and Pelvic Body Block for FMVSS 210 Test,” Appendix E.

Comments

The Alliance, Navistar, DTNA, EMA, Hino and Honda all noted or alluded to the lack of knowledge or experience testing with the FAD. DTNA commented that the suppliers and availability of the FADs are unknown. FSC asked if there would be “approved manufacturers” of the FAD. The Alliance suggested reopening the comment period to allow manufacturers time to procure and test with the FAD and stated that initial quotes from Humanetics indicated a 26-week lead-time before the first products can be delivered. The Alliance suggested that the FADs be made available for round-robin testing. Both Honda and the Alliance suggested conducting a technical workshop to demonstrate the use of the FAD and go over any technical questions and concerns associated with it.

In response to the SNPRM, JCI noted that it had conducted preliminary testing with the FAD and had not experienced any of the technical concerns raised in its NPRM comments. It stated that the FAD may develop into a feasible test device which helps to reduce variability, set-up time, and testing costs.

Agency Response

NHTSA understands the commenters' concerns that at the time the NPRM was published the FAD was not available. However, the FAD design information has been publicly available since the NPRM. After the NPRM was published, two commenters asked for the 3D design drawings, and we made these available upon request (and placed in the docket a memo stating so).

To date, the agency has received only a limited number of requests for the 3D drawings. Manufacturers have had ample time to fabricate and test with FADs; the NPRM was published in 2012 and the 2015 SNPRM (published in 2015) explicitly stated that NHTSA was still considering replacing the body blocks with the FAD or incorporating the FAD as an optional testing tool. Moreover, the concerns with respect to a lack of familiarity with the FAD are also addressed by the decision to give manufacturers the option to continue to certify to the requirements with the body blocks.

NHTSA-2012-0036-0002.

Any supplier or manufacturer is free to manufacture the FAD, and the design information that we have made publicly available is sufficient to fabricate the FAD. With respect to the comment regarding a compliance workshop, we received no further inquiries about this possibility. With respect to the comment about round-robin testing, NHTSA will make its FADs available to manufacturers or test laboratories upon request.

6. Testing Costs

i. Costs of Testing With the FAD

In the NPRM we estimated the cost of each FAD (FAD1 or FAD2) to be approximately $8,000. The agency assumed that a vehicle manufacturer or test facility would purchase a set of two FAD1s and three FAD2s, and that the principal cost associated with the NPRM is the one-time purchase cost of $40,000.

The NPRM stated that we believe there would be cost savings associated with using the FADs because they require less effort, time, and personnel to install in the test vehicle, and that over time these efficiencies would offset the one-time purchase cost of the FADs. In the NPRM, we estimated that the use of the FADs would result in a labor cost savings of $18.75 per vehicle test and on average a time savings of 5 minutes per seat installation.

Comments

FSC, which has a small test lab, stated that it would acquire five or more FADs, which would cost at least $40,000. Navistar commented that it has numerous test facilities and would require a dozen FADs (an initial investment of $96,000).

The Recreation Vehicle Industry Association (RVIA) commented that most motorhome manufacturers are small-volume manufacturers, and that motorhome manufacturers faced with expanded testing using new FAD equipment would confront massively (and potentially crippling) testing costs, with minimal ability to recapture test costs by spreading them across the units sold. RVIA argued that these costs would contrast markedly with large volume automobile manufacturers, which can test one unit of a model that represents tens or hundreds of thousands of similar units produced. Both EMA and DTNA commented that it is unknown whether the test set-up with the FAD results in less effort and time in a heavy-duty truck since no testing was done on these vehicles.

Global, the Alliance, and DTNA also commented that there would be additional certification costs, not considered in the NPRM, resulting from disharmonization. This subject is discussed in section V.C.10, Regulatory Alternatives.

Agency Response

Although vehicle manufacturers or test laboratories might purchase larger quantities of FADs than assumed in the NPRM to meet their testing needs, additional FADs are not necessary for

testing based on the FMVSS No. 210 performance requirements. Test labs typically test one vehicle at a time, and vehicles typically do not have more than five adjacent seating positions (that would be tested simultaneously). In addition, we believe that the useful life of the FADs can be measured in decades because of the materials with which it is constructed, and any cost can be amortized over this long life. For vehicle designs with long production lives, such as heavy vehicles, the testing cost would be spread over many years. We recognize that smaller-volume manufacturers would find it more difficult to recover these costs. However, it is likely that small-volume manufacturers would contract out testing services, thus the cost of the of purchasing the FADs would not be incurred by them directly. Another potential solution to defray cost might be for the RVIA to purchase FADs for the use of their members.

The test cost savings expected from the FAD's ease of use should apply equally as well to heavy-duty vehicles as well as light vehicles. The handling and positioning of the body blocks (mainly the torso body block) require more time and effort than seating the FAD regardless of vehicle type. The Karco final report included a section on the FAD's ease of use that discussed the installation time savings (6.75 minutes per seating position) and noted that, unlike the body blocks, it does not require multiple installation attempts. The research test reports docketed with the NPRM noted that the FADs were much easier to position than the current body blocks.

ii. Potential Re-Certification Costs

The NPRM stated that the use of the FAD would not affect the stringency of the seat belt assembly anchorage strength test.

Comments

Several vehicle manufacturers and vehicle manufacturer associations expressed concerns regarding the potential need for additional testing to ensure that the seat belt assembly anchorages certified with the current body blocks remain compliant when the FAD is used for testing.

The Alliance, EMA, Hino, Navistar, DTNA, and RVIA commented that vehicle manufacturers would have to perform expensive additional certification testing to ensure that their vehicles continued to be compliant when tested with the FAD. For example, the Alliance stated that even if a vehicle modification is not necessary, the new test hardware and procedures could require additional certification testing, which would require significant additional cost because many vehicles have numerous body styles and seating arrangements, and testing costs include bucks, seats, seat belts, body preparation time, test set up and tear down and disposal of scrap materials. Similarly, EMA commented on the need for additional validation testing with the FAD and stated that to ensure that existing heavy-duty truck models remain compliant to FMVSS No. 210 when tested using FADs, manufacturers would have to either prove that testing with the new FAD is equivalent to testing with the current body blocks, or re-test to ensure compliance of vehicles produced after the effective date of the rule. EMA commented that, at a minimum, one test would be required to establish equivalency of the FAD and the body blocks, and that test (which destroys a cab shell) is estimated to cost between $20,000 and $30,000. More likely, a manufacturer would have to conduct many tests to ensure equivalency for all seat, seat belt, and seat belt anchorage configurations in all its models. For example, Navistar estimated that such an equivalency evaluation could cost $670,000, and that the only alternative to establishing equivalency of FADs would be to re-test every product that a manufacturer plans to continue selling after the new rule is effective, which would be prohibitively expensive. Additionally, if testing disclosed a discrepancy between the FAD and the body blocks, the manufacturer would incur the costs of implementing a solution and would also need to address its potential liabilities from sold vehicles.

RVIA commented that if NHTSA finalized the FAD, the final rule should permit manufacturers to continue certifying to the anchorage strength requirements with the current body blocks until such time (regardless of how long) as new testing is made necessary by applicable changes in seating or vehicle structure, to allow motorhome manufacturers to gradually implement the new requirements and at least partially mitigate implementation costs.

Agency Response

As we explained above, the agency's indicant tests on passenger vehicle and bus seats do not indicate that using the FAD affected the compliance of the tested seat belt assembly anchorages; there were no test failures (see section V.A.4). However, considering the comments to the NPRM suggesting that manufacturers might conclude that to certify to the anchorage strength requirements using the FAD they would have to conduct additional certification testing, NHTSA has decided to retain and modify the test procedure using the longstanding body blocks (which is discussed in detail in section V.B). Accordingly, if a manufacturer has a concern with the FAD—for example, if it believes the FAD would not be practicable for a particular vehicle, or that it would have to conduct costly testing or design to re-certify a vehicle platform—it may certify to the body block compliance option instead.

7. Incorporation by Reference

Under regulations issued by the Office of the Federal Register (1 CFR 51.5(b)), an agency, as part of a final rule that includes material incorporated by reference, must summarize in the preamble of the final rule the material it incorporates by reference and discuss the ways the material is reasonably available to interested parties or how the agency worked to make materials available to interested parties.

In this final rule, NHTSA incorporates by reference material entitled “Drawing Package for the Force Application Device 1 (FAD1), April 9, 2024” and “Drawing Package for the Force Application Device 2, April 9, 2024,” consisting of engineering drawings and specifications for the force application device that NHTSA will use to assess the compliance of seat belt assembly anchorages with FMVSS No. 210 if the manufacturer selects that compliance option. The FAD consists of an upper torso portion and a pelvic portion hinged together to form a one-piece device and is available in two sizes.

NHTSA has placed a copy of the material in the docket for this final rule. Interested persons can download a copy of the material or view the material online by accessing

www.Regulations.gov,

telephone 1-877-378-5457, or by contacting NHTSA's Chief Counsel's Office at the phone number and address set forth in the

FOR FURTHER INFORMATION CONTACT

section of this document. The material is also available for inspection at the Department of Transportation, Docket Operations, Room W12-140, 1200 New Jersey Avenue SE, Washington, DC, Telephone: (202) 366-9826.

B. Body Blocks

The SNPRM announced that the agency was considering maintaining the current body blocks and refining the test procedure to specify the positioning of the body blocks more clearly so that manufacturers are informed of the range of positions that may be tested to determine compliance. After the

SNPRM was published, the agency docketed the additional research it had conducted to develop and validate the zones (as well as additional testing with the FAD). The agency received comments on the proposed zone concept in response to both the SNPRM and the subsequently docketed research. In this section we address those comments and explain NHTSA's decision to retain the current body blocks while refining the test procedure to respond to the

Chrysler

decision and clarify the test procedure.

Unless otherwise noted, the comments summarized below were in response to the 2015 SNPRM.

1. Retention of Body Blocks and Appropriateness of Specifying Zones for Body Block Placement

The SNPRM announced that the agency was considering maintaining the current body blocks and proposed a preliminary concept that consisted of specifying zones within which the body blocks would be placed for testing purposes, as it has done in FMVSS No. 222, “School bus passenger seating and crash protection.”

The procedure in FMVSS No. 222 establishes a zone in which the body block must be located when testing school bus passenger seating and restraining barriers. Specifically, after the preload application is complete, the origin of the torso body block radius, at any point across the torso body block thickness, must lie within a zone defined by specified boundaries.

Comments

The Alliance, FSC, Global, Honda, IMMI, and JCI all supported the continued use of the body blocks, and JCI, the Alliance, and IMMI specifically supported refining the test procedure to make it more objective and repeatable. For example, JCI commented that the current test procedure is unclear and potentially inconsistent. Several commenters suggested alternative approaches to specify the position of the body blocks instead of the zone approach. These suggestions are discussed in section V.B.7, Alternative Solutions.

However, some commenters appeared to question the appropriateness of specifying zones for the FMVSS No. 210 anchorage strength test. Global commented that the test setup is overly complex, making it difficult to obtain repeatable test results and increasing the time needed for test setup. FSC shared Global's stated concern about the complexity of the procedure and space limitations when conducting in-vehicle testing. Vans and minivans with a GVWR under 10,000 lb, have space constraints, especially when there are no rear windows and in rear-rows with four DSPs. Alliance, Global, and IMMI stated they were concerned that zones that would be valid for a wide range of vehicles would be too large, resulting in excessive variability (this is discussed further in section V.B.4). The Alliance recommended harmonizing with ECE R14 requirements for positioning the pelvic and torso block during the initial test set-up, including against the seat back. Global and FSC similarly suggested that the body blocks be placed against the seat back. Honda did not agree with the zone concept because it would result in disharmonization. (Harmonization is further discussed in section V.C.10.)

Agency Response

The final rule will retain the body blocks along with a refined test procedure that more clearly specifies the positioning of the blocks and will adopt the FAD as an optional test device. If manufacturers are not comfortable with the FAD, they may continue to use the body blocks. As explained in more detail below, NHTSA is, consistent with the decision in

Chrysler,

amending the body block test procedure to clearly specify the placement of the body blocks at preload.

NHTSA acknowledges that the finalized test procedure does add complexity to the current test procedure, which places no restrictions on the starting location of the body blocks. However, this change is both necessary and practicable. It is necessary because in

Chrysler

the D.C. Circuit determined that the existing test procedure did not provide manufacturers with adequate notice of where NHTSA would position the body blocks. However, NTHSA's testing showed that testing using the finalized zones is practicable. For example, there are methods for assisting the positioning of the body blocks in the allowable zones (

e.g.,

positioning aids, using lasers and a Faro Arm to ensure proper positioning, etc.)

that can be readily implemented by test laboratories. For vehicles with extreme space or accessibility constraints, sections of the vehicle can be removed to improve access and visibility. The zones also improve test repeatability by limiting the positioning of the body blocks. Comments regarding the size of the zones are discussed in detail in section V.B.4 and the alternatives suggested by commenters are discussed in section V.B.7.

“Development of Positioning Zones for FMVSS No. 210 Body Blocks,” pgs. 39-46.

2. Reference Point for Determining Zone Locations

The zone used in FMVSS No. 222 is defined with reference to the school bus torso belt adjusted height (TBAH)

and the SgRP. The SNPRM announced the possibility of using similar zones for the FMVSS No. 210 testing, but did not discuss how the proposed zone boundaries would be determined. That determination was discussed in the research report NHTSA docketed in 2018.

Specifically, that report set out the zones specified in this final rule and explained how they were developed. The zones are specified in relation to the SgRP, which is a design point determined by the vehicle manufacturer that represents a specific landmark near the hip of a 50th percentile adult male seated in the driver's seat. The SgRP is similar to, but different from, the H-point, which is the hip point as determined by placing a two-dimensional manikin in the seat.

The school bus torso belt adjusted height is defined in S3 of Standard No. 210 as the vertical height above the seating reference point (SgRP) of the horizontal plane containing a segment of the torso belt centerline located 25 mm to 75 mm forward of the torso belt height adjuster device, when the torso belt retractor is locked and the torso belt is pulled away from the seat back by applying a 20 N horizontal force in the forward direction through the webbing at a location 100 mm or more forward of the adjustment device as shown in Figure 5 (of FMVSS No. 210).

“Development of Positioning Zones for FMVSS No. 210 Body Blocks.”

SAE J826 JUL95 defines and specifies a procedure, including a manikin, for determining the location of the H-point. NHTSA's regulations define the H-point as the pivot center of the torso and thigh on the three-dimensional device used in defining and measuring vehicle seating accommodation, as defined in Society of Automotive Engineers (SAE) Recommended Practice J1100: Motor Vehicle Dimensions, revised in February 2001. 49 CFR 571.3.

Comments

Honda recommended that the zones be based on the SgRP instead of the TBAH. Honda stated that while the TBAH of school bus seats is not variable (because the seat belts are contained in the seats), the TBAH in other types of passenger vehicles is variable, leading to instances in which the zone is higher than the passenger's torso.

IMMI shared Honda's stated concern about the variability of the TBAH in vehicles other than school buses, and stated that this variability would lead to large zones or setup problems. IMMI recommended that NHTSA instead use the H-point. However, IMMI identified what it viewed as potential issues with using the H-point. It stated that if not provided by a seat or vehicle manufacturer for the seat to be tested prior to the actual test, the testing

agency will become responsible for determining the location of the H-point. It also stated that the SAE J826 machine does not always position well in the seat due to the bolsters and cushion contours, leading to variations in H-point determinations. To accommodate this variation, according to IMMI, there may be a need for an increase to the alignment zone, which could lead to variation in FMVSS No. 210 performance test results. The Alliance recommended using either the SgRP or H-point instead of the TBAH, because using the TBAH would introduce too much variability in body block positioning, which could lead to infeasible zones.

FSC developed a positioning procedure that defined the positioning of the body blocks relative to one another, and submitted data relating to this procedure. However, FSC reported that this procedure did not work well since the reference plane was attached to the pelvic body block and therefore moved when a preload was applied. FSC stated that it was providing the data for informational purposes and was not suggesting it be adopted.

Agency Response

NHTSA agrees with the commenters' concerns about using the TBAH. The final zones do not use the TBAH and instead are specified with reference to the SgRP. We decided to use the SgRP and not the H-point because the seat positioning provided for a more adequate torso location.

NHTSA appreciates FSC's comment and agrees that its concept would be difficult to implement, given that the body blocks are independent of each other, and their positioning depends on a variety of other factors, such as the design and weight of the body blocks (see section V.B.3). We believe the body block zone concept adequately addresses these factors because they were considered during the development of the zones.

3. Applicability of Zones to a Range of Vehicle and Seat Designs and Factors Affecting Position of Body Blocks at Preload

In the SNPRM, NHTSA stated that it had initiated research to aid in the development of the zones bounding the initial placement for the current body blocks. NHTSA explained that the research would evaluate the zone concept across different vehicle types (including heavy vehicles) and seat configurations and develop zone boundaries that would be feasible and practicable for all or most vehicles.

Comments

NHTSA received a variety of comments to the SNPRM regarding factors that affect the preload positioning of the body blocks.

IMMI, JCI, EMA, the Alliance, and Global commented that body block position would depend on seat and seat belt designs. IMMI further commented that the body blocks would not necessarily fit well in all seats due to variations in seat cushion contours, seat back size and bolster shape. EMA similarly commented that changes to the FMVSS No. 210 certification test procedures designed to work for passenger cars may not work for heavy trucks. It noted that while FMVSS No. 222 applies only to rigid school bus bench seats (which are different than seats used in heavy trucks (

e.g.,

air suspension seats)), FMVSS No. 210 specifies seat belt anchorage requirements for a broad range of motor vehicles, including medium and heavy-duty trucks. It stated that without testing of a broad range of heavy-duty trucks, NHTSA cannot know for certain whether it is feasible to establish appropriate body blocks zones for heavy-duty trucks. EMA further stated (in its comments on the 2018 notice of availability) that the additional technical reports NHTSA docketed did not alleviate its concerns because they do not contain any data with respect to the feasibility of the body blocks on the medium- and heavy-duty trucks built by its member companies, and suggested that the reports do not properly address the unique aspects of the broad range of medium and heavy-duty vehicles (

e.g.,

tractors, refuse trucks, parcel delivery vans, etc.). Accordingly, EMA argued that NHTSA should exempt vehicles with a GVWR greater than 10,000 pounds from the new requirements. IMMI commented that the body block position at the start of the test (

i.e.,

when the test load is applied) is affected by how tight the seat belt is pre-tensioned during setup, which affects the movement of the blocks during the preload or initial loading phase of the pull tests.

IMMI also stated that achieving consistent positioning of the torso block is made challenging by the mass of the torso body block and the mass of the load chain, so that unless supported prior to application of sufficient pull load, the block will drop from initial set-up position. IMMI stated that additional setup is required to hold the torso blocks in place prior to actual testing; IMMI uses a temporary hoist chain to support the torso block until sufficient preload is achieved to securely position the block for full test loads. IMMI commented that this method is not always acceptable when dealing with enclosed seating or multiple position tests and additional alternative means for vertical support must be devised. Ultimately, tests results may possibly be impacted depending on support type. IMMI accordingly suggested revising the design of the torso block to simplify and reduce mass.

FSC conducted an analysis on the movement of the body blocks up to and during preload with different seat belt and seat types and provided its findings.

It measured the displacement with (1) no connections to the hydraulic cylinders (rest), (2) with chains connected to hydraulic cylinders, and finally (3) at the FMVSS No. 210 recommended preload[s] of 136 kg and 227 kg (300 lb and 500 lb) for Type I & Type II seats respectively.

See

Attachment 2 of FSC's comment for details (NHTSA-2012-0036-0027).

Agency Response

After reviewing the comments on the SNPRM, NHTSA carried out research to develop zones for the body blocks that would be appropriate for the anchorage strength test. To ensure that the zones would apply to a wide variety of types of vehicles and seats, the agency's research considered the factors identified by the SNPRM commenters, as well as other factors that could affect body block position at preload. These factors included vehicle-specific parameters (such as the seat design and the overall seat belt system geometry) and test-specific parameters (such as the force application angle). The zones in the final rule are based on data from body blocks positioned in a variety of vehicles, seats, and seat-belt configurations. The zones are based on data from a range of different passenger vehicles, and were mathematically expanded to accommodate an even wider range of vehicles. The zones were validated on three heavy vehicles—specifically, two school bus seats (an IMMI school bus seat and a C.E. White school bus seat) and one motorcoach (an Amaya motorcoach) seat. Although the agency did not test the zones in every single possible type of medium- and heavy-duty vehicle, we believe NHTSA's testing shows that the zones are valid for a wide range of vehicles, including medium- and heavy-duty vehicles. Given the extensive use of the body blocks over the years, we believe IMMI's concerns about the body blocks not being an adequate test device for testing a wide variety of seat designs has not been borne out in practice. Because the agency's research included a variety

of seat and seat belt designs, the zones in the final rule are large enough to account for this variety.

With respect to IMMI's comment regarding seat belt tension and routing, NHTSA's fleet study did find that the amount of seat belt webbing pulled out from the retractor had an effect on body block placement in the fore/aft direction (x-plane). The study attempted to address the pre-tension of the seat belt by marking the belt at the D-ring at the desired length and locking it at this position for the remaining positioning attempts on that seat. Testing laboratories can put these actions into practice to facilitate positioning of the body blocks in a vehicle; testing laboratories can adjust the seat belt to the length necessary so that the body block is within the zone at preload. Similarly, if testing is performed with replacement webbing or cable, the length of the replacement material can be chosen to determine a fore/aft position in the required zone. In addition, the routing of the belt on the torso block can be used for small adjustment to increase the distance between the torso and pelvic block to avoid interference. This technique was not required in NHTSA's fleet study because contact (interference) between the blocks was not observed before or during application of the preload.

Removal of slack is not the same concept with the FAD as it is for the body blocks. A FAD sits on the seat and so slack can be easily removed whereas the body blocks potentially must be adjusted to be positioned in the zones and in some cases are held in place by the belt, particularly for the torso block. If there was slack in the belt the body block would not be held in place.

NHTSA has decided not to specify the weight or revise (simplify) the torso or pelvic body block designs. NHTSA's fleet study examined the effect of the mass of the torso body block and found that the positioning of the torso block was not sensitive to torso block mass. The weight of IMMI's torso body block seems to be greater than the blocks tested by NHTSA, so IMMI's torso block design and construction may be unnecessarily heavy. Both the torso and pelvic body blocks have been in use for decades and similar designs are used internationally. The agency has conducted numerous FMVSS No. 210 compliance tests through multiple test laboratories. Laboratory technicians use various techniques to facilitate the set-up of the torso body block, such as positioning devices. The agency's study identified several such techniques,

and the fleet study that was used to develop the zones used one of these techniques—a positioning aid placed on top of the pelvic body block—as well as having a laboratory technician position it by hand. Based on our testing, we believe that the final zones will accommodate different placement techniques.

“Development of Positioning Zones for FMVSS No. 210 Body Blocks,” pgs. 13-16 (NHTSA-2012-0036-0041).

One parameter NHTSA did not evaluate in the fleet study is the effect of the hardware used to connect the body blocks to the force actuators (

e.g.,

chains). While FSC's analysis does suggest that the seat type and connection to the force actuators have some effect on the position of the body blocks at preload, NHTSA's testing showed that the connection method does not have a meaningful effect on the position of the body blocks and the finalized zones will accommodate the effects of this test parameter.

4. Size of Zones, Variability of Test Results, and Effect on Compliance

The SNPRM explained that NHTSA was considering specifying zones like those specified in FMVSS No. 222, but did not otherwise discuss the size of the zones, or the variability of test results and whether currently produced vehicles certified before the establishment of the zones would continue to comply with the standard. The reports docketed with the notice of availability in 2018 did provide this information (see section IV.B).

Comments

The Alliance, Global, and IMMI stated they were concerned that zones that would be valid for a wide range of vehicles would be too large, resulting in excessive variability. The Alliance stated that the FMVSS No. 222 zone would be too large, resulting in significant variability in belt force vectors and system performance with the torso blocks placed at the extreme ends of the zone. The Alliance also stated that the zones would permit interactions between the torso and pelvic blocks that could result in load transfer between the blocks, which could result in non-representative loading onto the seat belt assembly anchorages, and such variability would require manufacturers to run additional compliance testing, and could also drive additional cost and weight into vehicles. Global and IMMI similarly argued that factors such as the give of the seat belt system, deflection of the seat cushion, variation in seat cushion contour, seat back size, torso belt anchor location, and bolster shape would affect the position of the body blocks and make consistent positioning a challenge; these factors may necessitate a large zone, which could lead to variation in test results. Global also commented that the FMVSS No. 222 test procedure is not suitable for use in FMVSS No. 210 because the test setup is overly complex, and it is difficult to ensure consistent test repeatability when positioning the body blocks.

EMA stated that even if it were possible to establish appropriate body block zones that would accommodate all seat and seat belt assembly configurations in all heavy-duty vehicles, it would be prohibitively expensive to re-certify all existing vehicles to comply with the new requirements.

Agency Response

As an initial matter, we note that even if there is variability in test results in the sense that a vehicle model may pass the anchorage strength test with the body blocks at one location in the zone, but fail the test when the body block is placed at another location in the zone, this variability is attributable to the vehicle's performance, not the test. The final zones give manufacturers clear notice of where NHTSA may position the body blocks for testing. Manufacturers are responsible for ensuring compliance at all points in the zones.

In any case, while we believe the final rule's zones are large enough to account for a variety of vehicles and seat types, they are still relatively modest in size, particularly from the side-profile. (See section IV.B for the zone dimensions.) The zone for the torso body block target point measures 530 mm in length by 240 mm in width by 245 mm in height (20.9 in. by 9.4 in. by 9.6 in.) and the zone for the pelvic body block target point measures 340 mm in length by 205 mm in width by 145 mm in height (13.4 in. by 8.1 in. by 5.7 in.). We also have seen no data or evidence to suggest that there will be large variability in force vectors or test results. To address the Alliance's concern about testing at the zone extremes, we ran an indicant test on a minivan with the body blocks at the longitudinal extremes of the zones recorded in the field study. There was no effect on the seat belt anchors meeting the load requirements of FMVSS No. 210. In addition, as noted earlier, NHTSA performed several indicant tests with preliminary versions of the zones on a variety of light vehicles, and did not record any test failures. Moreover, in the agency's forty-plus year history of testing for compliance with the anchorage strength requirements, test failures have been uncommon. According to the agency's records, for testing from 1972 to the present, there were 327 compliance tests

for FMVSS No. 210 and only 23 test failures.

(For a response to the Alliance's comment regarding interactions between the body blocks see section V.B.7.)

This tally includes failures related to any of the FMVSS No. 210 requirements as well as what the agency would typically consider “non-tests” (

i.e.,

tests that could not be completed due to equipment or testing issues), so the number of actual test failures for the anchorage strength requirements is likely lower than this. The agency was unable to locate all the past test reports to determine the number of failures more accurately. The agency believes, however, that the overall magnitude of the number of test failures reflected in the available records accurately reflects the magnitude of actual test failures.

For the same reasons, we also have not seen any data or evidence to suggest that testing to the final zones will result in different test outcomes compared to the existing test procedure. The current test procedure has no constraints on the positioning of the body blocks. The refined test procedure in this final rule establishes allowable zones for the positioning of the body blocks. It therefore reduces the set of permissible test conditions. Because the universe of test conditions is smaller, the variability of possible test outcomes is also smaller. Thus, we do not foresee issues with compliance.

Moreover

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