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

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.

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.

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.

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).

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.