 
				NHTSA Interpretation File Search
Overview
NHTSA's Chief Counsel interprets the statutes that the agency administers and the standards and regulations that it issues. Members of the public may submit requests for interpretation, and the Chief Counsel will respond with a letter of interpretation. These interpretation letters look at the particular facts presented in the question and explain the agency’s opinion on how the law applies given those facts. These letters of interpretation are guidance documents. They do not have the force and effect of law and are not meant to bind the public in any way. They are intended only to provide information to the public regarding existing requirements under the law or agency policies.
Understanding NHTSA’s Online Interpretation Files
NHTSA makes its letters of interpretation available to the public on this webpage.
An interpretation letter represents the opinion of the Chief Counsel based on the facts of individual cases at the time the letter was written. While these letters may be helpful in determining how the agency might answer a question that another person has if that question is similar to a previously considered question, do not assume that a prior interpretation will necessarily apply to your situation.
- Your facts may be sufficiently different from those presented in prior interpretations, such that the agency's answer to you might be different from the answer in the prior interpretation letter;
- Your situation may be completely new to the agency and not addressed in an existing interpretation letter;
- The agency's safety standards or regulations may have changed since the prior interpretation letter was written so that the agency's prior interpretation no longer applies; or
- Some combination of the above, or other, factors.
Searching NHTSA’s Online Interpretation Files
Before beginning a search, it’s important to understand how this online search works. Below we provide some examples of searches you can run. In some cases, the search results may include words similar to what you searched because it utilizes a fuzzy search algorithm.
Single word search
 Example: car
 Result: Any document containing that word.
Multiple word search
 Example: car seat requirements
 Result: Any document containing any of these words.
Connector word search
 Example: car AND seat AND requirements
 Result: Any document containing all of these words.
Note: Search operators such as AND or OR must be in all capital letters.
Phrase in double quotes
 Example: "headlamp function"
 Result: Any document with that phrase.
Conjunctive search
Example: functionally AND minima
Result: Any document with both of those words.
Wildcard
Example: headl*
Result: Any document with a word beginning with those letters (e.g., headlamp, headlight, headlamps).
Example: no*compl*
Result: Any document beginning with the letters “no” followed by the letters “compl” (e.g., noncompliance, non-complying).
Not
Example: headlamp NOT crash
Result: Any document containing the word “headlamp” and not the word “crash.”
Complex searches
You can combine search operators to write more targeted searches.
Note: The database does not currently support phrase searches with wildcards (e.g., “make* inoperative”).
Example: Headl* AND (supplement* OR auxiliary OR impair*)
Result: Any document containing words that are variants of “headlamp” (headlamp, headlights, etc.) and also containing a variant of “supplement” (supplement, supplemental, etc.) or “impair” (impair, impairment, etc.) or the word “auxiliary.”
Search Tool
NHTSA's Interpretation Files Search
| Interpretations | Date | 
|---|---|
| ID: 07-004380-3asOpenDietmar K. Leicht Secretary General Federation of European Manufacturers of Friction Materials Robert-Perthel-Str. 49 D-50739 Kln Germany Dear Mr. Leicht: This responds to your letter in which you ask whether AMECA Standard VESC V-3 is still a legal requirement and mandatory in [the U.S.]. You stated that your members would like to know which legal requirements must be fulfilled for the export of brake linings to the United States. You cited brake linings for the aftermarket which are approved in Europe by ECE Regulation No. 90 and OE brake linings offered on the market as original replacement parts which are approved in Europe by ECE Regulation No. 13 (13H). By way of background, the National Highway Traffic Safety Administration (NHTSA) is authorized under 49 U.S.C. Chapter 301 to issue Federal motor vehicle safety standards applicable to new motor vehicles and items of motor vehicle equipment. NHTSA does not approve motor vehicles or motor vehicle equipment, nor do we endorse any commercial products. Instead, our statute establishes a self-certification process under which each manufacturer is responsible for certifying that its products meet all applicable safety standards. The agency periodically tests vehicles and equipment items for compliance with the standards, and also investigates reports of safety-related defects. There is currently no Federal motor vehicle safety standard for new or replacement linings used on motor vehicles sold in the United States. However, new vehicles are required to be certified to brake safety standards which specify minimum performance requirements under a variety of different test conditions. While the brake linings used on a vehicle could affect the vehicles ability to meet some of the minimum performance requirements, the requirements do not establish any separate performance requirements for the brake linings.   The Federal requirements operate separately from the State law requirements. States are free to impose their own requirements on motor vehicles and motor vehicle equipment, unless such requirements are preempted by Federal law. We are unable to provide information about possible State requirements for brake linings. Standard V-3 was promulgated by the Vehicle Equipment Safety Commission (VESC), and specified minimum requirements and uniform test procedures for motor vehicle brake linings. VESC ceased operations in January 1984. With regard to Federal law, the VESC V-3 standard is not and never was a legal requirement. However, we cannot provide information as to whether some or all of the requirements of this standard may have been adopted as State laws. In your letter, you referenced AMECA. We note that, according to its website, the Automotive Manufacturers Equipment Compliance Agency, Inc. (AMECA) was incorporated in late 1994 to continue providing the same safety equipment services to the states that the American Association of Motor Vehicle Administrators had provided since 1967. Finally, brake linings are items of "motor vehicle equipment" and are subject to the notification and remedy (recall) provisions of 49 U.S.C. 30118-30120. If a manufacturer or NHTSA determines that the product contains a safety-related defect, the manufacturer is responsible for notifying purchasers of the defective vehicle or item of motor vehicle equipment and remedying the problem free of charge. (This "recall" responsibility is borne by the vehicle manufacturer in cases in which the equipment is installed on a new vehicle by or with the express authorization of that vehicle manufacturer.) I am enclosing an information sheet we prepared for new manufacturers of motor vehicles and motor vehicle equipment that provides additional information about relevant Federal states and NHTSA standards and regulations affecting motor vehicle and motor vehicle manufacturers. We hope this information has been helpful. If you have any further questions, you may call Ari Scott of my staff at (202) 366-2992. Sincerely yours, Anthony M. Cooke Chief Counsel Enclosure ref:VSA d.11/20/08 | 2008 | 
| ID: 1985-02.40OpenTYPE: INTERPRETATION-NHTSA DATE: 06/07/85 FROM: AUTHOR UNAVAILABLE; Jeffrey R. Miller; NHTSA TO: Mr. M. Mizuguchi TITLE: FMVSS INTERPRETATION TEXT: 
 Mr. M. Mizuguchi Ashimori Industry Co., Ltd. 12, 4-chome Yokobori, Higashi-ku Osaka, Japan 
 Dear Mr. Mizuguchi: 
 Your letter of February 28, 1985, was forwarded to my office for reply. You asked whether the webbing attached to a buckle you intend to use must meet the webbing width requirement of S4.2 of Standard No. 209, Seat Belt Assemblies. The webbing is enclosed in a plastic sheath. As explained below, the webbing must meet the width requirement of the standard. 
 S4.2 of Standard No. 209 provides that the "width of the webbing in a seat belt assembly shall be not less than 1.8 inches, except for portions that do not touch a 95th percentile adult male with the seat in any adjustment position and the seat back in the manufacturer's nominal design riding position when measured under the conditions prescribed in S5.1(a)." The purpose of S4.2 is to ensure that belt webbing which comes into contact with an occupant has a minimum width that spreads the load imposed by the belt in a crash. By requiring webbing to spread rather than concentrate the load, the belt width requirement helps minimize the possibility of webbing-caused injury. 
 In the case of your design, the webbing is enclosed in a tightly-fitting plastic sheath. You state that the webbing/sheath combination can come into contact with an occupant. The sheath enclosed with your sample is made from an easily deformable plastic. Thus, when the crash loads are imposed by the belt, the sheath will deform and the crucial factor in concentrating the load on an occupant is the width of the belt. Since the webbing/sheath combination can contact and impose crash loads on an occupant, the agency concludes that the webbing must meet the minimum width requirement of S4.2. 
 If the webbing were encased in a reinforced sheath that did not appreciably deform under loading, the agency would consider both the width of the webbing and its encasing sheath in determining whether the requirement of S4.2 was met. 
 I have enclosed the sample of your product sent with your letter. If you have any further questions, please let me know. Sincerely, 
 Jeffrey R. Miller Chief Counsel 
 Enclosure 
 Ref. No M/M02-28 Osaka Feb, 28, 1985 
 Messrs. Department of Transportation National Highway Traffic Safety Administration Washington, D. C. 20590, U. S. A. 
 Attn: Mr. Francis Armstrong Director Office of Vehicle Safety Compliance Enforcement 
 Dear Mr. Francis Armstrong, 
 We'd like to ask you the following question. Recently, we are trying to make a soft and flexibility seat belt system, and then the enclosed buckle is one of our sample. This sample is composed of narrow webbing and a little solid plastic boot. However, according to FMVSS NO. 209 item 4.2 (a) "webbing width" describing it's width should be not less than 1.8 inches (about 46mm), the problem of elongation and etc, it is very difficult for us to judge whether our sample does conform to regulation N0.209 on the view of interpretation of the Law or not. Of course, this assembly does meet with the requirement of seat belt assembly prescribing in NO. 209. When this sample is located in vehicle, we are afraid that this sample will touch slightly or enough to person's body. Here, we enclosed please find our sample of buckle side of seat belt assembly herewith. So could you pleases inform us of your official comments very soon. Your earliest written answer will be highly appreciated. Yours faithfully, 
 Ashimori Industry Co., Ltd. 
 M. Mizuguchi 
 encl. sample of bucket seat | |
| ID: 2884oOpen Robert R. Keatinge, Esq. Dear Mr. Keatinge: This is a response to your letter of December 4, 1987, asking this agency to clarify your understanding of 49 CFR 571.7(e). That section reads in part as follows: Combining new and used components. When a new cab is used in the assembly of a truck, the truck will be considered newly manufactured ...unless the engine, transmission, and drive axle(s) (as a minimum) of the assembled vehicle are not new, and at least two of these components were taken from the same vehicle. You referred to my August 11, 1987 letter to Mr. Ernest Farmer, and expressed concern that my having discussed only one aspect of 571.7(e) in that letter has led to some confusion. My letter to Mr. Farmer states that "a modified school bus or truck is not considered a 'new' vehicle if, at a minimum, the engine, transmission, and drive axle(s) are not new and at least two of these three listed components are taken from the same used vehicle." You stated that while my statement is "correct," my response did not address the first clause of this provision: "When a new cab is used in the assembly of a truck..." You asserted that, "a bus should not be considered 'new' unless a new body is attached to the chassis." Your assertion is correct with respect to 571.7(e), but there is another regulation that specifies a vehicle is "new" if an old body is combined with a new chassis. By its own terms, 571.7(e) applies only in situations where a new body is combined with either (1) mixed new and used chassis components, or (2) used components from different vehicles. You were correct, then, in asserting that 571.7(e) applies only to situations involving a new body. For the purposes of the Farmer letter, it was understood between Mr. Farmer and a member of my staff that the bus bodies in question were new, so that letter did not purport to address the question of combining an old bus body with new and or/used chassis components. Many of our prior interpretations have stated that a person who adds a new or used body to a new chassis to produce a school bus is considered the manufacturer of a new school bus, and must certify that the new bus conforms with all applicable safety standards, just as every other school bus manufacturer must. In this case, the new chassis is an incomplete vehicle. "Incomplete vehicle" is defined in 49 CFR 568.3 as: an assemblage consisting, as a minimum, of a frame and chassis structure, power train, steering system, suspension system, and braking system, to the extent that those systems are to be part of the completed vehicle, that requires further manufacturing operations, other than the addition of readily attachable components, such as mirrors or tire and rim assemblies, or minor finishing operations such as painting, to become a completed vehicle. When a new bus chassis is used to produce a vehicle, the person who adds a body - even an old body - is a final-stage manufacturer, within the meaning of 49 CFR 568.3. Final-stage manufacturers are required to certify that the completed vehicle conforms with all applicable Federal Motor Vehicle Safety Standards in effect on the date of manufacture. The date of manufacture for these buses cannot be earlier than the date on which the chassis manufacturer completed its work on the chassis and cannot be later than the date the final-stage manufacturer completed its manufacturing operations. See 49 CFR 567.5, Requirements for Manufacturers of Vehicles Manufactured in Two or More Stages. Note that neither 571.7(e) nor Part 568 would require a person to certify that a school bus complies with all applicable safety standards, if that person merely rebuilds or replaces an engine, drive axle, or transmission in a bus, or if that person places a used bus body on a used chassis. I hope you find this information helpful. Sincerely, 
 Erika Z. Jones Chief Counsel ref:57l#567#568 d:5/2/88 | 1988 | 
| ID: 1983-3.2OpenTYPE: INTERPRETATION-NHTSA DATE: 09/02/83 FROM: AUTHOR UNAVAILABLE; Frank Berndt; NHTSA TO: Peterson Manufacturing Company -- Paul Scully, Vice President TITLE: FMVSS INTERPRETATION TEXT: 
 
 Mr. Paul Scully Vice President Peterson Manufacturing Company 4200 East 135th Street Grandview, MO 64030 
 Dear Mr. Scully: 
 This is in reply to your letter of July 22, 1983, to Mr. Cavey of this agency. 
 With respect to paragraph S4.1.1.7 of Standard No.108 Lamps Reflective Devices, and Associated Equipment you have stated your understanding that paragraph applies only to turn signal lamps manufactured between January 1, 1972 and September 1, 1978, and that turn signal lamps must now comply with SAE Standard J588e, September 1970. 
 Paragraph S.4.1.1.7 did allow vehicular compliance with SAE J588d as an option to J588e. J588d required that any turn signal lamp used on a vehicle whose overall width was 80 inches or more have a minimum of 12 square inches effective projected luminous lens area. On the other hand, SAE J588e requires a minimum of 8 square inches effective projected luminous lens area on all single compartment rear turn signal lamps, regardless of vehicle width. However, on vehicles 80 inches or more in overall width, two turn signal lamps or compartments per side may be mounted closer together than 22 inches provided each meets single compartment photometric requirements and each has a minimum effective projected luminous lens area of 12 square inches. Thus, your understanding is correct. I would also point out that, pursuant to Section S4.7.1 of Standard No. 108, the continued manufacture of turn signal lamps meeting J588d is permissible as replacement equipment for vehicles manufactured between January 1, 1972 and September 1, 1978. Mr. Cavey has provided the copy of BMCS regulations which is enclosed. 
 Sincerely, Frank Berndt Chief Counsel 
 Enclosure 
 July 22, 1983 
 Mr. Kevin Cavey National Highway Traffic Safety Administration 400 Seventh Street SW Nassif Building Washington, DC 20590 
 Dear Kevin: 
 I need a copy of the Bureau of Motor Carrier Safety Regulations and I no longer have in my files the address of that agency. Would you be kind enough to telephone them and request that a copy of that booklet be forwarded to me. I would certainly appreciate it. On a completely separate subject, a question arose today concerning the meaning of Paragraph S4.1.1.7 in FMVSS 108. The specific question related to the square inches of area needed for a turn signal on vehicles over 80". 
 My interpretation of the regulation has been that turn signal lamps for vehicles over 80" must comply with J588e dated September, 1970. This standard requires 8 square inches of area for single compartment lamps. That standard also spells out that when lamps are mounted closer together than 22" on vehicles over 80", they must then individually meet all of the requirements and must be 12 square inches. 
 Paragraph S4.1.1.7 only applies to turn signal lamps manufactured between January 1, 1972 and September 1, 1978 and simply permitted compliance with the prior standard J588d. This specific paragraph, in my judgment, only relates to vehicles built between the dates spelled out above and does not impact the area requirements as otherwise spelled out in J588e. Specifically, it is our understanding that the rear turn signal area for single compartment lamps is eight square inches regardless of the width of the vehicle. The only exception to this requirement is spelled out in the SAE standard which states that the area must be 12 square inches if indeed the units are placed closer together than 22". Can you please advise me if my interpretation is correct? 
 Very truly yours, 
 Paul Scully Vice President 
 PS/sld | |
| ID: nht92-9.18OpenDATE: February 7, 1992 FROM: Barry Felrice -- Associate Administrator for Rulemaking, NHTSA TO: Robert A. Rogers -- Director, Automotive Safety Engineering, EAS, GENERAL MOTORS TITLE: None ATTACHMT: Attached to USG 2846 Part III dated 11/18/91 from Robert A. Rogers to Barry Felrice; Also attached to NHTSA memorandum dated 12/10/91 from Barry Felrice to Paul Jackson Rice (OCC 6741) TEXT: This responds to your request that this agency determine that the new antitheft device to be installed on the MY 1992 General Motors Pontiac Bonneville line, represents a de minimis change in the system that was the basis for the agency's previous granting of a theft exemption for the car line beginning in MY 1991, and that therefore the Pontiac Bonneville vehicles containing the new device would be fully covered by that exemption. The agency has reviewed the changes to the system and for the following reasons concludes that the differences between the original system and one installed on the MY 1992 Pontiac Bonneville constitute a de minimis change. As you are aware, the Pontiac Bonneville car line was granted an exemption, pursuant to 49 CFR Part 543, from antitheft marking because General Motors showed that the antitheft device to be used in lieu of marking on the car line was likely to be as effective as parts marking. This antitheft device is known as the "PASS-KEY" antitheft system. The exemption was issued on April 4, 1991, and appeared in the Federal Register on April 9, 1991 (56 FR 14413). As was stated in the April 1991 Federal Register notice, the "PASS-KEY" antitheft system utilizes an ignition key, an ignition lock cylinder and a decoder module. Before a vehicle can be started, the electrical resistance of a pellet embedded in the shank of the key must be sensed by elements in the lock cylinder and its value compared to a fixed resistance in the decoder module. In your letter, it was stated that beginning from MY 1992, two design changes were made in the "PASS-KEY" antitheft device that is standard equipment on the Pontiac Bonneville. The new system on the Bonneville is known as "PASS-KEY II," and differs from "PASS-KEY" as follows. First, in "PASS-KEY II," if a key other than the one with proper resistance for the vehicle is inserted, the decoder module will shut down the fuel injector pulses to the engine for three minutes plus or minus eighteen seconds. In "PASS-KEY," this shut down period is two to four minutes. Second, if, during the time the decoder module has shut down in "PASS-KEY II," trial and error attempts are made to start the engine with various keys, the timer will not reset to zero, as is the case with "PASS-KEY." GM states that this difference in functions will provide a similar level of performance as "PASS-KEY" since the "PASS-KEY II" module, while shut down, will ignore further attempts to start the system by means other than use of a key with the proper resistance pellet. Any further unauthorized attempt after the initial three minute shut down time will result in the module shutting down again. After reviewing the proposed changes to the componentry and performance of the antitheft device on which the exemption was based, the agency concludes that the changes are de minimis. In addition to providing some aspects of performance not provided by the original device, "PASS-KEY II" also continues to provide the same aspects of performance provided by the original device and relies on essentially the same componentry to provide that performance. Therefore, it is not necessary for General Motors to submit a petition to modify the exemption pursuant to 49 CFR Part 543.9(c)(2). If General Motors does not implement the new antitheft device as described in your letter for MY 1992, we request that this agency be notified of such decisions. | |
| ID: nht95-2.73OpenTYPE: INTERPRETATION-NHTSA DATE: May 9, 1995 FROM: John Womack -- Acting Chief Counsel, NHTSA TO: Musa K. Farmand -- Gonzalez & Farmand, P.A. TITLE: NONE ATTACHMT: ATTACHED TO 04/27/95 LETTER FROM MUSA K. FARMAND TO MARY VERSAILLES TEXT: Dear Mr. Farmand: This responds to your letter of April 27, 1995. Your letter concerns a law suit in which you represent plaintiffs injured in an automobile accident. In this law suit, the counsel for the defendant has moved to amend his answer to assert that 49 CFR 571 .208, paragraph S4.1.5.2(c)(2) requires each state to allow for mitigation of damages in any seat belt use law and that paragraph preempts the Florida mandatory seat belt law. According to your letter, the Florida law "does not allow a mitigation of dam ages defense with respect to an alleged failure to wear a seat belt." As explained below, the National Highway Traffic Safety Administration agrees with you that the Florida safety belt use law is neither expressly nor impliedly preempted by Federal law. Purpose of Paragraph S4.1.5.2(c) (2) Before discussing the issue of preemption, I want to discuss the background and purpose of Paragraph S4.1.5.2(c)(2). That paragraph was added to Standard No. 208, Occupant Crash Protection (49 CFR 571.208) as part of a final rule issued July 17, 1984 co ncerning automatic restraints (49 FR 28962). That final rule required all new cars to have automatic protection (air bags or automatic belts) starting in the 1990 model year. The final rule included a provision that the automatic restraint requirement would be rescinded if the Secretary of Transportation determined, not later than April 1, 1989, that a sufficient number of States had enacted belt use laws meeting certain minimum criteria to cover at least two-thirds of the U.S. population (paragraph S 4.1.5). Under S4.1.5, the Secretary was not required to make any determination about any State safety belt laws. In fact, the Secretary never did so, in part because not enough States adopted mandatory seat belt use laws of any sort prior to April 1, 1 989. Because no determination was made under S4.1.5, the automatic restraint requirements are now in effect for all passenger cars. The minimum criteria were set forth in S4.1.5.2 of Standard No. 208. n1 One of the criteria was "a provision specifying that the violation of the belt usage requirement may be used to mitigate damages . . ." (S4.1.5.2(c)(2)). However, S4.1.5 neither pur ported to require nor was intended to require States to enact safety belt use laws. In addition, S4.1.5 did not require that any State safety belt use laws had to incorporate the minimum criteria of S4.1.5.2. Paragraph S4.1.5 merely provided that the S ecretary would rescind the automatic restraint requirement if he or she determined that a sufficient number of States enacted laws which met the criteria of S4.1.5.2 by April 1, 1989. n1 Your letter correctly notes that this provision was deleted from Standard No. 208 by a final rule issued on September 2, 1993 (58 FR 46551). Preemption The Florida safety belt use law is not and never has been either expressly or impliedly preempted by Federal law. Standard No. 208 was issued under 49 U.S.C. Chapter 301 which expressly preempts state laws only to the extent provided by section 30103. That section provides for the express preemption of State motor vehicle safety standards that are not identical to Federal standards. However, the Florida seat belt law is not a motor vehicle safety standard within the meaning of Chapter 301, since it does not regulate motor vehicle or motor vehicle equipment performance. Accordingly, the Florida law is not express ly preempted. The Florida law is not impliedly preempted because (1) Congress has not occupied the field of regulation of the behavior of motor vehicle occupants; and (2) the Florida seat belt law does not conflict with any Federal law or interfere with the objectives of Federal law. I hope this information has been helpful. If you have other questions or need some additional information, please contact Mary Versailles of my staff at this address or by phone at (202) 366-2992. | |
| ID: nht90-4.30OpenTYPE: Interpretation-NHTSA DATE: October 2, 1990 FROM: Paul Jackson Rice -- Chief Counsel, NHTSA TO: S. Kadoya -- Manager, Safety and Technology, Mazda Research and Development of North America, Inc. TITLE: None ATTACHMT: Attached to letter dated 11-7-89 from S. Kadoya to S.P. Wood TEXT: This responds to your request for interpretations of several safety standards and the Bumper Standard, in connection with a planned "active" suspension system. I regret the delay in responding to your letter. Your questions are responded to below. By way of background information, the National Highway Traffic Safety Administration (NHTSA) does not provide approvals of motor vehicles or motor vehicle equipment. Under the statutes administered by this agency, it is the responsibility of the manufac turer to ensure that its vehicles and equipment comply with applicable standards. The following represents our opinion based on the facts provided in your letter. According to your letter, Mazda is concerned about the protocol of compliance testing of vehicles equipped with an active suspension system. This concern arises because many standards do not specify a suspension height that is to be used during complianc e testing. As you noted, this has not been a concern for conventional suspension systems, since they do not provide for variable height. Mazda's planned active suspension system would be actuated by hydraulic fluid or compressed air, with control pressure being developed by a hydraulic pump or air compressor driven off the engine. Consequently, the active suspension system would be opera tional only when the vehicle's engine is operating. At vehicle speeds in excess of "z" mph, where z is greater than 35 mph, the suspension height would be lowered by "x" mm from the nominal or design position for vehicle operation. If the engine/vehicl e were not used for several consecutive days, pressure in the control system would fall such that the supension height may be lowered from the nominal or design position for vehicle operation by "y" mm, where y is greater than x. The suspension height w ould return to the nominal or design position for vehicle operation after such an extended period of inoperation almost immediately after starting the vehicle's engine. Before discussing your specific questions, I would like to discuss more generally the issue of how compliance is determined in situations where a standard does not specify a particular test condition. In issuing Federal motor vehicle safety standards, N HTSA attempts to specify all relevant test conditions. The agency does this as part of ensuring that its standards are objective and practicable. As a practical matter, however, it is not possible to specify every conceivable test condition. This is p articularly true for ones which may only be relevant to as-yet-undeveloped technologies. In cases where a standard does not specify a particular test condition, we believe there are several relevant factors to consider in interpreting the standard. First, in the absence of specification of a particular test condition, we believe there is a presumption that the requirements need to be met regardless of such test condition, since the standard does not include any language which specifically limits applicability of its requirements to such test condition. For example, where a standard does n ot specify suspension height, its requirements may need to be met at all heights to which the suspension can be adjusted. Before reaching such a conclusion, however, we also consider the language of the standard as a whole and its purposes. Even if a s tandard is silent as to a particular test condition, the language of the standard or its purposes may indicate limitations on such test condition. Finally, in situations where a limitation on a particular test condition may appear to be appropriate, we also must consider whether the limitation is sufficiently clear, both with respect to justification and specificity, to be appropriate for interpretation. For example, in a situation where it may appear to be reasonable to limit a particular test condit ion but it is not obvious what particular limitation should be adopted, it would be inappropriate to select a particular limitation by interpretation. Instead, such a decision should be reached in rulemaking. I will now address the specific questions asked in your letter. Standard No. 108, Lamps, Reflective Devices, and Associated Equipment In asking about Standard No. 108, you stated the following: NHTSA has previously issued an interpretation of the requirements of FMVSS No. 108; at the request of a confidential applicant and dated February 12, 1985, with respect to active suspension equipped vehicles. This interpretation stated that the requirem ents of FMVSS 108 must be meet (sic),"...at any time in which..." lamps, reflective devices, and associated equipment are to be,"...operated for its intended purpose." Consequently, headlamps, tailamps, stoplamps, the license plate lamp, and side marker lamps, must comply with the location requirements of FMVSS No. 108 whenever the vehicle's ignition is in the "on" postiion. Conversely, reflex reflectors, and turn signal lamps that also function as hazard warning signal flashers must comply with the lo cation requirements when the vehicle's ignition is in either the "on" or "off" position. However, it is Mazda's interpretation that hazard warning flashers are not intended to be operational for a period of days, but rather for a period of hours, at max imum, only. You then asked two questions, (1) whether Mazda's understanding of the subject NHTSA interpretation is accurate, and (2) whether Mazda's interpretation of the maximum intended operating duration of hazard warning signal flashers is correct. I note that the February 1985 interpretation was written in the context of a vehicle with a variable height system actuated by hydraulic fluid. In that particular system, the hydraulic pressure relaxed over a period of about three hours after the ignition was turned off, with the result that the vehicle assumed a lower height than it would have during driving. NHTSA stated the following: We believe that the minimum height requirement should be met for any lamp at any time in which it is operated for its intended purpose. Since vehicles at rest do not require use of headlamps, the minimum height requirement would be measured at the point after the ignition is on and when the car begins to travel (your letter implies that the time lag between turning on the ignition and restoration of a complying mounting height is a matter of seconds). On the other hand, the hazard warning signal lamps are frequently operated when the vehicle is stopped, and therefore the minimum mounting height of turn signal lamps, through which they operate, must be met with the ignition off, even if the system requires three hours to deplete itself and lower the v ehicle to its minimum height. With respect to your question of whether Mazda's understanding of the interpretation is correct, I would like to note two points. First, while you state that "the requirements of FMVSS 108" must be met at any time in which lamps, reflective devices, and associated equipment are to be operated for their intended purpose, our interpretation was limited to standard's minimum height requirement. While we are prepared, if asked, to address other requirements, our interpretations should be understood to be limited to their specific facts and conclusions. Second, while our interpretation only addressed headlamps and hazard warning signal lamps, you applied the interpretation for headlamps to taillamps, stoplamps, the license plate lamp, and side marker lam ps, and the interpretation for hazard warning signal lamps to reflex reflectors. We concur with this application, with respect to Standard No. 108's minimum height requirement. We do not agree with Mazda's suggested interpretation of the maximum intended operating duration of hazard warning signal flashers. You would apparently like us to conclude that Standard No. 108's minimum height requirement for hazard warning signal fla shers does not apply after a vehicle's ignition has been turned off for a matter of days. In addressing how Standard No. 108 applies in the absence of a specification for vehicle height, our February 1985 interpretation differentiates between situations where the vehicle is operating and where it is not. Looking at the purpose of the require ments in question, we believe it is obvious that the minimum height requirement for headlamps is only relevant in situations where the vehicle is operating, while the minimum height for hazard warning signal lamps is also relevant to situations where the vehicle is stopped and the ignition turned off. However, we believe that any determination that Standard No. 108's minimum height requirement for hazard warning signal flashers should not apply after a specified number of hours after the ignition has be en turned off is one that would need to be addressed in rulemaking. It is therefore my opinion that the minimum mounting height of hazard warning signal lamps must be met at all heights with the ignition off, even if the system requires days to deplete itself and lower the vehicle to its minimum height. If you believe that a time limitation should be placed on this requirement, I note that you can submit a petition for rulemaking requesting such a change. Standard No. 111, Rearview Mirrors You requested an interpretation of section S5.1.1 of Standard No. 111, which generally requires a passenger car's rearview mirror to "provide a field of view with an included horizontal angle measured from the projected eye point of at least 20 degrees, and sufficient angle to provide a view of level road surface extending to the horizon beginning at a point not greater than 200 feet to the rear of the vehicle...." You noted that since the specified procedures for determining the location of the driver 's eye reference points are made referenced to points with the vehicle's cabin, your active suspension system would not affect these measurements. However, different vehicle heights would be relevant to whether there is a view of level road surface exte nding to the horizon beginning at a point not greater than 200 feet to the rear of the vehicle. You stated that, based on "intended purpose," Mazda's interpretation of Standard No. 111 is that the requirements of this standard are to be met when the vehi cle's ignition is in the "on" position as rearview mirrors are not intended to be used when the vehicle's engine is not operating. You then asked two questions, (1) whether Mazda's interpretation of the requirements of FMVSS No. 111 with respect to the state of the vehicle's ignition switch is correct, and (2) for the purposes of compliance testing to the requirements of FMVSS No. 1 11, what means of maintaining the intended suspension height for a given speed and operating condition would be satisfactory to NHTSA. We agree that the field of view requirement specified in S5.1.1 for rearview mirrors need not be met for vehicle heights that only occur when the engine is not on, since the requirement is only relevant in situations where the vehicle is operating. Howe ver, the requirement would need to be at all vehicle heights that occur during vehicle operation, under the loading conditions specified in S5.1.1. With respect to the issue of how suspension height should be maintained for purposes of compliance testing, you note early in your letter that, for reasons of practicality and safety, a vehicle's engine is not actually operational during compliance testi ng. However, since the active suspension system derives its power from the vehicle's engine, the system's ability to maintain and regulate suspension height is only possible during engine operation. You therefore indicated that Mazda is seeking guideli nes (for several standards) by which Mazda may be able to establish a means to maintain the intended suspension height for compliance testing purposes in the absence of engine operation. We are not able, in an interpretation, to specify a particular means for maintaining suspension height for compliance testing in the absence of engine operation. However, the basic principle that should be followed in selecting a means for maintaining s uspension height is that it should not result in different test results than would occur if testing could be conducted with suspension height being maintained by engine operation, i.e., what would happen in the real world. This should be relatively straightforward for section S5.1.1 of Standard No. 111, since the test is static. For a crash test, it is important that a vehicle not be altered in any way that would change the vehi cle's crash performance relevant to the aspect of performance being tested. Standard No. 204, Steering Control Rearward Displacement In asking about Standard No. 204, you stated the following: Section S4 of this standard specifies the compliance parameter for this standard. Section S5 specifies the testing conditions to determine compliance with this standard. Section S5.1 specifies that the vehicle be loaded to its unloaded vehicle weight. Section S5.5 specifies that the vehicles fuel tank be filled with Stoddard solvent to any capacity between 90 and 95 percent of the total capacity of the tank. Mazda's interpretation of the requirements of this standard is that they are to be met when the vehicle's ignition switch is in the "on" position only. Furthermore, Mazda interprets the vehicles suspension height pursuant to S5.1 and S5.5 to be the intended suspension height for the vehicle given the conditions of S4, i.e., 30 mph vehicle speed and steered wheels are positioned straight ahead. You then asked whether Mazda's interpretation of the requirements of FMVSS No. 204 are correct. As discussed below, we agree that Standard No. 204's requirements need to be met only at the suspension height that occurs at a 30 mph vehicle speed and with steered wheels positioned straight ahead. Standard No. 204 specifies requirements limiting the rearward displacement of the steering control into the passenger compartment to reduce the likelihood of chest, neck, or head injury. These requirements must be met in a 30 mile per hour perpendicular impact into a fixed collision barrier. While the standard specifies a number of test conditions, it does not specify suspension height. Looking at the Standard No. 204 as a whole, we believe it is clear that NHTSA explicitly decided to limit the standard's evaluation of steering control rearward displacement to how vehicles perform in 30 mph perpendicular impacts, even though the require ments have relevance at lower and higher speeds. Therefore, we agree that the standard's requirements need to be met only at suspension heights that occur at a 30 mph vehicle speed and with steered wheels positioned straight ahead. With respect to Mazda's question concerning means of maintaining intended suspension height for compliance testing, please see our discussion provided with respect to Standard No. 111. Standard No. 208, Occupant Crash Protection In asking about Standard No. 208, you stated the following: Section S8.1.1(d), "Vehicle test attitude," specifies the procedure for determining the vehicle test attitude that is to be used for testing. Specifically, this section requires that the vehicle's pretest attitude, "...shall be equal to either the as delivered or fully loaded attitude or between the as delivered and fully loaded attitude." The as delivered attitude is defined by S8.1.1(d) as being, "...the distance between a level surface and a standard reference point on the test vehicle's body, directly above each wheel opening, when the vehicle is in its "as delivered" condition. The "as delivered" condition is the vehicle as received at the test site..." Because it is highly likely that the test vehicle wil l not have been operated for a period of days prior to arriving at the test site, the suspension height may have fallen by "y" mm. The fully loaded attitude is defined as the attitude of the vehicle when loaded in accordance with S8.1.1(a) or (b) and a determination of the height of the suspension at the fully loaded condition is made from the same level surface, using the same standard reference points, as were used to determine the "as delivered" condition. The definition of the "as delivered" condi tion is quite clear. However, Mazda interprets the "fully loaded condition" of the vehicle to be the condition when the vehicle's ignition is "on." In this instance it is likely that the height of the standard reference points on the vehicles body when in the "fully loaded condition" relative to the level surface will be greater than for the "as delivered" condition. Conversely, conventional vehicle suspension systems will likely have an "as delivered" height greater than the "full loaded" height. H owever, this fact is of no importance as S8.1.1(d) states that the pretest vehicle attitude may be, "...between the as delivered and the fully loaded attitude." With respect to the injury criteria specified by section S6 of this standard, Mazda's interp retation is that these criteria must be met with the vehicle's ignition in the "on" position only. You then asked three questions, (1) whether Mazda's interpretation of the definition of the "fully loaded condition" is correct with respect to the condition of the ignition switch, (2) whether Mazda's interpretation of the irrelevance of the relative re lationship between the "as delivered" and "fully loaded" conditions is correct, and (3) whether Mazda's interpretation of the meaning of "between the as delivered and the fully loaded attitude" is correct. In addressing your questions, I will begin by noting that Standard No. 208 specifies occupant protection requirements which must be met in specified crash tests at any impact speed up to and including 30 mph. While the standard specifies a number of tes t conditions, it does not specify suspension height. However, the standard does specify vehicle attitude, which is closely related to suspension height. In addressing how Standard No. 208 applies in the absence of a specification for vehicle height, th e relationship between the standard's attitude specification and vehicle height must be considered. Section S8.1.1(d) specifies the attitude of the vehicle during testing, i.e., the angle of the vehicle relative to the ground. This test condition ensures that the vehicle is not overly tilted toward the front or back, or to one side. The section accom plishes this purpose by specifying that, during a compliance test, the height of the vehicle at each wheel is within a specified range. This range, which may be somewhat different for each wheel, is determined by looking at the vehicle in the "as delive red" condition and the "fully loaded" condition. A vehicle must meet the requirements of Standard No. 208 when its height at each wheel is anywhere within the specified ranges. On first glance, one might read section S8.1.1(d) to create a height requirement, since ranges of height are determined under that section (at each wheel). This would be incorrect, except in a very narrow sense, since Standard No. 208 does not specify, for vehicles with variable height suspension systems, what suspension height should be used in the two conditions ("as delivered" and "fully loaded") where the specified ranges of height are determined under section S8.1.1(d). Looking at the Standard No. 208 as a whole, we believe it is clear that NHTSA explicitly decided to limit the standard's evaluation of occupant crash protection in frontal impacts to how vehicles perform in impacts of 30 mph or less, even though the requ irements also have relevance at higher speeds. It is our interpretation that the frontal crash test requirements need to be met at all suspension heights that can occur at speeds of 30 mph or less, with the vehicle operational. It is also our interpret ation that the crash test requirements need to be met only at suspension heights that can occur at the speed used in the crash test. A remaining issue is how section S8.1.1(d) applies for vehicles with variable height suspension systems. As discussed below, vehicle attitude should be determined under this section using the actual suspension setting (or equivalent, if the setting is a utomatic) to be used in a crash test. For purposes of illustration, I will assume a vehicle with two very different suspension height settings. It would not be appropriate to conclude that the ranges of height determined under section S8.1.1(d) should simultaneously cover both suspension he ights. Such ranges would be very large, and would not ensure that the vehicle is not overly tilted toward the front or back, or to one side. Moreover, such ranges would not be relevant to the real world, with respect to vehicle attitude. Traditional vehicles can be viewed as having a single suspension "setting." This single suspension condition is used in determining vehicle attitude under section S5.8.8.1. The ranges of height result from the differences in loading under the "as deliv ered" and "fully loaded" conditions. A single suspension "setting" (or equivalent, if the setting is automatic) should similarly be used in determining vehicle attitude for vehicles with variable height suspension systems. The "setting" should be the one to be used in a crash test. With respect to Mazda's question concerning means of maintaining intended suspension height for compliance testing, please see our discussion provided with respect to Standard No. 111. You also asked for an interpretation of section S8.2.7 of Standard No. 208. That section specifies additional conditions to be used for lateral moving barrier crash testing. Section S8.2.7(a) states that the vehicle is at rest in its "normal attitude." You stated that Mazda interprets the meaning of "normal attitude" to be that vehicle attitude which is intended when the vehicle's ignition is in the "on" condition, with the vehicle loaded pursuant to S8.1.1(a) or (b), and while the vehicle is at rest. Standard No. 208 provides manufacturers the option of either equipping their vehicles with safety belts or meeti ng certain alternative requirements, including lateral moving barrier crash test requirements. These requirements are relevant at all vehicle heights that can occur during vehicle operation, regardless of speed. Moreover, NHTSA has not decided to limit the standard's evaluation of this aspect of safety performance to how vehicles perform at certain limited speeds. It is our interpretation that the lateral moving barrier crash test requirements, if applicable, must be met at all suspension heights that can occur with the vehicle operational. "Normal attitude" is the attitude determined under section S8.1.1(d). As discussed above, attitude for vehicles equipped with variable height suspension systems is determined under section S8.1.1(d) using the ac tual suspension setting (or equivalent, if the setting is automatic) to be used in a crash test. Standards No. 212, Windshield Mounting; No. 219, Windshield Zone Intrusion; No. 301, Fuel System Integrity In asking about Standards No. 212, No. 219, and No. 301, you noted that NHTSA has previously issued an interpretation to Mazda about how these standards apply to adjustable height suspension systems. In a letter dated August 10, 1982, the agency address ed a vehicle equipped with a suspension system having two height positions, one for normal highway driving and another for off-road driving, which could be selected by the driver. NHTSA stated the following: (Safety Standards No. 212, No. 219, and No. 301) do not specify a height adjustment because almost all vehicles have a single, set adjustment. . . After careful consideration, it is the agency's position that such a vehicle capable of variable height adj ustment would have to comply with the vehicle adjusted to any position that is possible. This is true because the vehicle could be driven on the highway, for example, even if it were adjusted to the off-road position. Consequently, it is important that the vehicle comply with the standards in all positions. You noted that while suspension height could be adjusted by the driver for the system discussed in the agency's previous interpretation, the active suspension system you are currently considering would use an on-board electronic controller to select susp ension height, and suspension height would not be adjustable by the driver. Consequently, according to your letter, only one unique set of suspension height parameters is possible for a given vehicle speed and loading condition as is the case with conve ntional suspension systems. You stated that because it is possible to determine exactly what the intended suspension height should be for a given situation, it is Mazda's opinion that the test vehicle should be tested at the intended suspension height g iven the specified speed and loading conditions. You also stated that, using an "intended purpose" argument, Mazda concludes that the requirements of the three standards are to be met only when the vehicle's ignition is "on." You then asked whether thes e suggested interpretations are correct. Standard No. 212 specifies windshield retention requirements that must be met in a specified frontal crash test at any impact speed up to and including 30 mph. Similarly, Standard No. 219 specifies windshield zone intrusion requirements that must be met in a specified frontal crash test at any impact speed up to and including 30 mph. Standard No. 301 specifies fuel system integrity requirements for several specified crash tests. These include a frontal crash test similar to those in Standards No. 212 and No. 219. Requirements for this test must be met at any impact speed up to and including 30 mph. Other tests include a rear moving barrier crash test, a lateral moving barrier crash test, and a static rollover test. We agree that the requirements of Standards No. 212, No. 219, and No. 301 need not be met for vehicle heights that only occur when the engine is not on, since the requirements are only relevant in situations where the vehicle is operating. Looking at th e three standards as a whole, we believe it is clear that, for the frontal tests specified by the three standards, NHTSA decided to limit the standards' evaluation of safety performance to how vehicles perform in impacts of 30 mph or less, even though th e requirements have relevance at higher speeds. It is our interpretation that the frontal crash test requirements specified by these standards need to be met at all suspension heights that can occur at speeds of 30 mph or less, with the vehicle operatio nal. It is also our interpretation that the crash test requirements need to be met only at suspension heights that can occur at the speed used in the crash test. We reach a different conclusion for Standard No. 301's other crash test requirements. These requirements are relevant at all vehicle speeds and suspension heights. Moreover, NHTSA has not decided to limit the standard's evaluation of these aspects of s afety performance to how vehicles perform at certain limited speeds. It is our interpretation that these crash test requirements must be met at all suspension heights that can occur with the vehicle operational. Part 581 Bumper Standard In asking about the Part 581 Bumper Standard, you noted that NHTSA has previously issued several interpretations of how the standard applies to vehicles with adjustable height suspension systems. In a letter to Subaru dated May 6, 1986, NHTSA stated the following: Given the absence of a specific test condition concerning suspension height, it is our interpretation that a vehicle must be capable of meeting the standard's damage criteria at any height position to which the suspension can be adjusted. There is no la nguage in the test requirements of the standard limiting their applicability to "the manufacturer's nominal design highway adjusted height position." This interpretation is consistent with the purpose of the Bumper Standard, set forth in section 581.2, to reduce physical damage to the front and rear ends of a passenger motor vehicle from low speed collisions. If a vehicle's suspension could be adjust ed so that its bumper height resulted in bumper mismatch with other vehicles in the event of low speed collisions, the reduction in physical damage attributable to the Bumper Standard would be defeated in whole or part. In another letter, dated February 12, 1985, NHTSA stated that a vehicle is "required to meet the pendulum test of Part 581 in any vehicle use scenario in which the vehicle operates, and the barrier test of Part 581 when the engine is idling." You suggested, for the barrier test, that the agency's May 1986 interpretation may be inappropriate for your active suspension system, since your system provides for only one suspension height when the engine is idling. You also suggested, for the pendu lum test, that these interpretations seem to be in conflict with the Bumper Standard's stated purpose to reduce physical damage to motor vehicles in low speed collisions. We assume that you are referring to the fact that your suspension system has heigh ts that occur only at speeds greater than 35 mph. You then requested that NHTSA provide an interpretation of Part 581 with respect to your system. In addressing how Part 581 applies to vehicles equipped with an active suspension system, I will address separately the standard's barrier and pendulum tests. For the barrier test, a vehicle must meet specified damage criteria after an impact into a fix ed barrier that is perpendicular to the line of travel of the vehicle, at 2.5 mph. Section 581.6 sets forth conditions applicable to bumper testing. Under section 581.6(c), at the onset of a barrier impact, the vehicle's engine is operating at idling s peed. Looking at the Bumper Standard as a whole, we believe it is clear that NHTSA decided to limit the barrier test's evaluation of bumper performance to how vehicles perform in 2.5 mph frontal impacts, even though the requirements have relevance at lower and higher speeds and when the vehicle is nonoperational. It is our interpretation that the barrier test requirements specified by this standard need to be met at all suspension heights that can occur at 2.5 mph. We reach a different conclusion for the pendulum test, which serves the purpose of creating a bumper height requirement. This requirement is relevant at all vehicle speeds and suspension heights, and when the vehicle is nonoperational. I note that whil e Mazda is correct that the Bumper Standard's stated purpose is to reduce physical damage to motor vehicles in low speed collisions, NHTSA has justified the bumper height requirement on safety concerns related to "higher speed collisions." In proposing Standard No. 215, the predecessor of Part 581, the agency stated: . . . in higher speed collisions the tendency of a bumper to override another or to ride under or over a guardrail creates hazards for vehicle occupants. Vehicles with interlocking bumpers block traffic and expose their occupants to considerable danger, particularly if they attempt to get out to unlock bumpers. By overriding or underriding a guardrail, a bumper may strike a supporting post, or similar fixed object, with serious consequences for the vehicle and its occupants. 35 FR 17999, November 24, 1970. The relevance of the bumper height requirement to nonoperational situations is also clear, e.g., to help protect parked cars. Moreover, NHTSA has not decided to limit the bumper height requirement to how vehicles perform at certain limited speeds. It is our interpretation that the pendulum test requirements must be met at all suspension heights that can occur, regardless of ve hicle speed or whether the ignition is turned on. This interpretation is consistent with an October 18, 1978 letter to Nissan, in which NHTSA addressed how the pendulum test applies to vehicles equipped with height control systems, including automatic height control systems. Among other things, the age ncy stated the following: . . . There is no language in the pendulum test requirements of the standard which would limit their applicability to only the ignition-on or ignition-off situation or to the recommended driving position for normal roadways. The vehicle must be capable of meeting the pendulum test requirements at all stable bumper heights possible at unloaded vehicle weight. Thus, in the situations described in Question 1 and 2 of your letter, in which an automatic height control system is employed, the vehicle must comply with the pendulum test requirements in both the ignition-on and ignition-off positions . . . . I note that one of our past letters, a December 24, 1984 letter addressed to Porsche, appears to suggest that the pendulum test must be met in any setting in which the system operates "when the engine is idling." This might be read to suggest that the p endulum test need not be met when the vehicle is nonoperational. However, this interpretation cited section 581.6(c) in concluding that the engine is idling during Part 581 testing. Section 581.6(c) applies only to the barrier test and not the pendulum test. We therefore consider this interpretation to be incorrect to the extent that it is inconsistent with the analysis presented above. | |
| ID: 2705yOpen Mr. S. Kadoya Dear Mr. Kadoya: This responds to your request for interpretations of several safety standards and the Bumper Standard, in connection with a planned "active" suspension system. I regret the delay in responding to your letter. Your questions are responded to below. By way of background information, the National Highway Traffic Safety Administration (NHTSA) does not provide approvals of motor vehicles or motor vehicle equipment. Under the statutes administered by this agency, it is the responsibility of the manufacturer to ensure that its vehicles and equipment comply with applicable standards. The following represents our opinion based on the facts provided in your letter. According to your letter, Mazda is concerned about the protocol of compliance testing of vehicles equipped with an active suspension system. This concern arises because many standards do not specify a suspension height that is to be used during compliance testing. As you noted, this has not been a concern for conventional suspension systems, since they do not provide for variable height. Mazda's planned active suspension system would be actuated by hydraulic fluid or compressed air, with control pressure being developed by a hydraulic pump or air compressor driven off the engine. Consequently, the active suspension system would be operational only when the vehicle's engine is operating. At vehicle speeds in excess of "z" mph, where z is greater than 35 mph, the suspension height would be lowered by "x" mm from the nominal or design position for vehicle operation. If the engine/vehicle were not used for several consecutive days, pressure in the control system would fall such that the supension height may be lowered from the nominal or design position for vehicle operation by "y" mm, where y is greater than x. The suspension height would return to the nominal or design position for vehicle operation after such an extended period of inoperation almost immediately after starting the vehicle's engine. Before discussing your specific questions, I would like to discuss more generally the issue of how compliance is determined in situations where a standard does not specify a particular test condition. In issuing Federal motor vehicle safety standards, NHTSA attempts to specify all relevant test conditions. The agency does this as part of ensuring that its standards are objective and practicable. As a practical matter, however, it is not possible to specify every conceivable test condition. This is particularly true for ones which may only be relevant to as-yet-undeveloped technologies. In cases where a standard does not specify a particular test condition, we believe there are several relevant factors to consider in interpreting the standard. First, in the absence of specification of a particular test condition, we believe there is a presumption that the requirements need to be met regardless of such test condition, since the standard does not include any language which specifically limits applicability of its requirements to such test condition. For example, where a standard does not specify suspension height, its requirements may need to be met at all heights to which the suspension can be adjusted. Before reaching such a conclusion, however, we also consider the language of the standard as a whole and its purposes. Even if a standard is silent as to a particular test condition, the language of the standard or its purposes may indicate limitations on such test condition. Finally, in situations where a limitation on a particular test condition may appear to be appropriate, we also must consider whether the limitation is sufficiently clear, both with respect to justification and specificity, to be appropriate for interpretation. For example, in a situation where it may appear to be reasonable to limit a particular test condition but it is not obvious what particular limitation should be adopted, it would be inappropriate to select a particular limitation by interpretation. Instead, such a decision should be reached in rulemaking. I will now address the specific questions asked in your letter. Standard No. l08, Lamps, Reflective Devices, and Associated Equipment In asking about Standard No. l08, you stated the following: NHTSA has previously issued an interpretation of the requirements of FMVSS No. l08; at the request of a confidential applicant and dated February l2, l985, with respect to active suspension equipped vehicles. This interpretation stated that the requirements of FMVSS l08 must be meet (sic),"...at any time in which..." lamps, reflective devices, and associated equipment are to be,"...operated for its intended purpose." Consequently, headlamps, tailamps, stoplamps, the license plate lamp, and side marker lamps, must comply with the location requirements of FMVSS No. l08 whenever the vehicle's ignition is in the "on" postiion. Conversely, reflex reflectors, and turn signal lamps that also function as hazard warning signal flashers must comply with the location requirements when the vehicle's ignition is in either the "on" or "off" position. However, it is Mazda's interpretation that hazard warning flashers are not intended to be operational for a period of days, but rather for a period of hours, at maximum, only. You then asked two questions, (l) whether Mazda's understanding of the subject NHTSA interpretation is accurate, and (2) whether Mazda's interpretation of the maximum intended operating duration of hazard warning signal flashers is correct. I note that the February l985 interpretation was written in the context of a vehicle with a variable height system actuated by hydraulic fluid. In that particular system, the hydraulic pressure relaxed over a period of about three hours after the ignition was turned off, with the result that the vehicle assumed a lower height than it would have during driving. NHTSA stated the following: We believe that the minimum height requirement should be met for any lamp at any time in which it is operated for its intended purpose. Since vehicles at rest do not require use of headlamps, the minimum height requirement would be measured at the point after the ignition is on and when the car begins to travel (your letter implies that the time lag between turning on the ignition and restoration of a complying mounting height is a matter of seconds). On the other hand, the hazard warning signal lamps are frequently operated when the vehicle is stopped, and therefore the minimum mounting height of turn signal lamps, through which they operate, must be met with the ignition off, even if the system requires three hours to deplete itself and lower the vehicle to its minimum height. With respect to your question of whether Mazda's understanding of the interpretation is correct, I would like to note two points. First, while you state that "the requirements of FMVSS l08" must be met at any time in which lamps, reflective devices, and associated equipment are to be operated for their intended purpose, our interpretation was limited to standard's minimum height requirement. While we are prepared, if asked, to address other requirements, our interpretations should be understood to be limited to their specific facts and conclusions. Second, while our interpretation only addressed headlamps and hazard warning signal lamps, you applied the interpretation for headlamps to taillamps, stoplamps, the license plate lamp, and side marker lamps, and the interpretation for hazard warning signal lamps to reflex reflectors. We concur with this application, with respect to Standard No. l08's minimum height requirement. We do not agree with Mazda's suggested interpretation of the maximum intended operating duration of hazard warning signal flashers. You would apparently like us to conclude that Standard No. l08's minimum height requirement for hazard warning signal flashers does not apply after a vehicle's ignition has been turned off for a matter of days. In addressing how Standard No. l08 applies in the absence of a specification for vehicle height, our February l985 interpretation differentiates between situations where the vehicle is operating and where it is not. Looking at the purposes of the requirements in question, we believe it is obvious that the minimum height requirement for headlamps is only relevant in situations where the vehicle is operating, while the minimum height for hazard warning signal lamps is also relevant to situations where the vehicle is stopped and the ignition turned off. However, we believe that any determination that Standard No. l08's minimum height requirement for hazard warning signal flashers should not apply after a specified number of hours after the ignition has been turned off is one that would need to be addressed in rulemaking. It is therefore my opinion that the minimum mounting height of hazard warning signal lamps must be met at all heights with the ignition off, even if the system requires days to deplete itself and lower the vehicle to its minimum height. If you believe that a time limitation should be placed on this requirement, I note that you can submit a petition for rulemaking requesting such a change. Standard No. lll, Rearview Mirrors You requested an interpretation of section S5.l.l of Standard No. lll, which generally requires a passenger car's rearview mirror to "provide a field of view with an included horizontal angle measured from the projected eye point of at least 20 degrees, and sufficient angle to provide a view of level road surface extending to the horizon beginning at a point not greater than 200 feet to the rear of the vehicle...." You noted that since the specified procedures for determining the location of the driver's eye reference points are made referenced to points with the vehicle's cabin, your active suspension system would not affect these measurements. However, different vehicle heights would be relevant to whether there is a view of level road surface extending to the horizon beginning at a point not greater than 200 feet to the rear of the vehicle. You stated that, based on "intended purpose," Mazda's interpretation of Standard No. lll is that the requirements of this standard are to be met when the vehicle's ignition is in the "on" position as rearview mirrors are not intended to be used when the vehicle's engine is not operating. You then asked two questions, (l) whether Mazda's interpretation of the requirements of FMVSS No. lll with respect to the state of the vehicle's ignition switch is correct, and (2) for the purposes of compliance testing to the requirements of FMVSS No. lll, what means of maintaining the intended suspension height for a given speed and operating condition would be satisfactory to NHTSA. We agree that the field of view requirement specified in S5.l.l for rearview mirrors need not be met for vehicle heights that only occur when the engine is not on, since the requirement is only relevant in situations where the vehicle is operating. However, the requirement would need to be at all vehicle heights that occur during vehicle operation, under the loading conditions specified in S5.l.l. With respect to the issue of how suspension height should be maintained for purposes of compliance testing, you note early in your letter that, for reasons of practicality and safety, a vehicle's engine is not actually operational during compliance testing. However, since the active suspension system derives its power from the vehicle's engine, the system's ability to maintain and regulate suspension height is only possible during engine operation. You therefore indicated that Mazda is seeking guidelines (for several standards) by which Mazda may be able to establish a means to maintain the intended suspension height for compliance testing purposes in the absence of engine operation. We are not able, in an interpretation, to specify a particular means for maintaining suspension height for compliance testing in the absence of engine operation. However, the basic principle that should be followed in selecting a means for maintaining suspension height is that it should not result in different test results than would occur if testing could be conducted with suspension height being maintained by engine operation, i.e., what would happen in the real world. This should be relatively straightforward for section S5.l.l of Standard No. lll, since the test is static. For a crash test, it is important that a vehicle not be altered in any way that would change the vehicle's crash performance relevant to the aspect of performance being tested. Standard No. 204, Steering Control Rearward Displacement In asking about Standard No. 204, you stated the following: Section S4 of this standard specifies the compliance parameter for this standard. Section S5 specifies the testing conditions to determine compliance with this standard. Section S5.l specifies that the vehicle be loaded to its unloaded vehicle weight. Section S5.5 specifies that the vehicles fuel tank be filled with Stoddard solvent to any capacity between 90 and 95 percent of the total capacity of the tank. Mazda's interpretation of the requirements of this standard is that they are to be met when the vehicle's ignition switch is in the "on" position only. Furthermore, Mazda interprets the vehicles suspension height pursuant to S5.l and S5.5 to be the intended suspension height for the vehicle given the conditions of S4, i.e., 30 mph vehicle speed and steered wheels are positioned straight ahead. You then asked whether Mazda's interpretation of the requirements of FMVSS No. 204 are correct. As discussed below, we agree that Standard No. 204's requirements need to be met only at the suspension height that occurs at a 30 mph vehicle speed and with steered wheels positioned straight ahead. Standard No. 204 specifies requirements limiting the rearward displacement of the steering control into the passenger compartment to reduce the likelihood of chest, neck, or head injury. These requirements must be met in a 30 mile per hour perpendicular impact into a fixed collision barrier. While the standard specifies a number of test conditions, it does not specify suspension height. Looking at the Standard No. 204 as a whole, we believe it is clear that NHTSA explicitly decided to limit the standard's evaluation of steering control rearward displacement to how vehicles perform in 30 mph perpendicular impacts, even though the requirements have relevance at lower and higher speeds. Therefore, we agree that the standard's requirements need to be met only at suspension heights that occur at a 30 mph vehicle speed and with steered wheels positioned straight ahead. With respect to Mazda's question concerning means of maintaining intended suspension height for compliance testing, please see our discussion provided with respect to Standard No. lll. Standard No. 208, Occupant Crash Protection In asking about Standard No. 208, you stated the following: Section S8.l.l(d), "Vehicle test attitude," specifies the procedure for determining the vehicle test attitude that is to be used for testing. Specifically, this section requires that the vehicle's pretest attitude, "...shall be equal to either the as delivered or fully loaded attitude or between the as delivered and fully loaded attitude." The as delivered attitude is defined by S8.l.l(d) as being, "...the distance between a level surface and a standard reference point on the test vehicle's body, directly above each wheel opening, when the vehicle is in its "as delivered" condition. The "as delivered" condition is the vehicle as received at the test site..." Because it is highly likely that the test vehicle will not have been operated for a period of days prior to arriving at the test site, the suspension height may have fallen by "y" mm. The fully loaded attitude is defined as the attitude of the vehicle when loaded in accordance with S8.l.l(a) or (b) and a determination of the height of the suspension at the fully loaded condition is made from the same level surface, using the same standard reference points, as were used to determine the "as delivered" condition. The definition of the "as delivered" condition is quite clear. However, Mazda interprets the "fully loaded condition" of the vehicle to be the condition when the vehicle's ignition is "on." In this instance it is likely that the height of the standard reference points on the vehicles body when in the "fully loaded condition" relative to the level surface will be greater than for the "as delivered" condition. Conversely, conventional vehicle suspension systems will likely have an "as delivered" height greater than the "full loaded" height. However, this fact is of no importance as S8.l.l(d) states that the pretest vehicle attitude may be, "...between the as delivered and the fully loaded attitude." With respect to the injury criteria specified by section S6 of this standard, Mazda's interpretation is that these criteria must be met with the vehicle's ignition in the "on" position only. You then asked three questions, (l) whether Mazda's interpretation of the definition of the "fully loaded condition" is correct with respect to the condition of the ignition switch, (2) whether Mazda's interpretation of the irrelevance of the relative relationship between the "as delivered" and "fully loaded" conditions is correct, and (3) whether Mazda's interpretation of the meaning of "between the as delivered and the fully loaded attitude" is correct. In addressing your questions, I will begin by noting that Standard No. 208 specifies occupant protection requirements which must be met in specified crash tests at any impact speed up to and including 30 mph. While the standard specifies a number of test conditions, it does not specify suspension height. However, the standard does specify vehicle attitude, which is closely related to suspension height. In addressing how Standard No. 208 applies in the absence of a specification for vehicle height, the relationship between the standard's attitude specification and vehicle height must be considered. Section S8.l.l(d) specifies the attitude of the vehicle during testing, i.e., the angle of the vehicle relative to the ground. This test condition ensures that the vehicle is not overly tilted toward the front or back, or to one side. The section accomplishes this purpose by specifying that, during a compliance test, the height of the vehicle at each wheel is within a specified range. This range, which may be somewhat different for each wheel, is determined by looking at the vehicle in the "as delivered" condition and the "fully loaded" condition. A vehicle must meet the requirements of Standard No. 208 when its height at each wheel is anywhere within the specified ranges. On first glance, one might read section S8.l.l(d) to create a height requirement, since ranges of height are determined under that section (at each wheel). This would be incorrect, except in a very narrow sense, since Standard No. 208 does not specify, for vehicles with variable height suspension systems, what suspension height should be used in the two conditions ("as delivered" and "fully loaded") where the specified ranges of height are determined under section S8.l.l(d). Looking at the Standard No. 208 as a whole, we believe it is clear that NHTSA explicitly decided to limit the standard's evaluation of occupant crash protection in frontal impacts to how vehicles perform in impacts of 30 mph or less, even though the requirements also have relevance at higher speeds. It is our interpretation that the frontal crash test requirements need to be met at all suspension heights that can occur at speeds of 30 mph or less, with the vehicle operational. It is also our interpretation that the crash test requirements need to be met only at suspension heights that can occur at the speed used in the crash test. A remaining issue is how section S8.l.l(d) applies for vehicles with variable height suspension systems. As discussed below, vehicle attitude should be determined under this section using the actual suspension setting (or equivalent, if the setting is automatic) to be used in a crash test. For purposes of illustration, I will assume a vehicle with two very different suspension height settings. It would not be appropriate to conclude that the ranges of height determined under section S8.l.l(d) should simultaneously cover both suspension heights. Such ranges would be very large, and would not ensure that the vehicle is not overly tilted toward the front or back, or to one side. Moreover, such ranges would not be relevant to the real world, with respect to vehicle attitude. Traditional vehicles can be viewed as having a single suspension "setting." This single suspension condition is used in determining vehicle attitude under section S5.8.8.l. The ranges of height result from the differences in loading under the "as delivered" and "fully loaded" conditions. A single suspension "setting" (or equivalent, if the setting is automatic) should similarly be used in determining vehicle attitude for vehicles with variable height suspension systems. The "setting" should be the one to be used in a crash test. With respect to Mazda's question concerning means of maintaining intended suspension height for compliance testing, please see our discussion provided with respect to Standard No. lll. You also asked for an interpretation of section S8.2.7 of Standard No. 208. That section specifies additional conditions to be used for lateral moving barrier crash testing. Section S8.2.7(a) states that the vehicle is at rest in its "normal attitude." You stated that Mazda interprets the meaning of "normal attitude" to be that vehicle attitude which is intended when the vehicle's ignition is in the "on" condition, with the vehicle loaded pursuant to S8.l.l(a) or (b), and while the vehicle is at rest. Standard No. 208 provides manufacturers the option of either equipping their vehicles with safety belts or meeting certain alternative requirements, including lateral moving barrier crash test requirements. These requirements are relevant at all vehicle heights that can occur during vehicle operation, regardless of speed. Moreover, NHTSA has not decided to limit the standard's evaluation of this aspect of safety performance to how vehicles perform at certain limited speeds. It is our interpretation that the lateral moving barrier crash test requirements, if applicable, must be met at all suspension heights that can occur with the vehicle operational. "Normal attitude" is the attitude determined under section S8.l.l(d). As discussed above, attitude for vehicles equipped with variable height suspension systems is determined under section S8.l.l(d) using the actual suspension setting (or equivalent, if the setting is automatic) to be used in a crash test. Standards No. 2l2, Windshield Mounting; No. 2l9, Windshield Zone Intrusion; No. 30l, Fuel System Integrity In asking about Standards No. 2l2, No. 2l9, and No. 30l, you noted that NHTSA has previously issued an interpretation to Mazda about how these standards apply to adjustable height suspension systems. In a letter dated August l0, l982, the agency addressed a vehicle equipped with a suspension system having two height positions, one for normal highway driving and another for off-road driving, which could be selected by the driver. NHTSA stated the following: [Safety Standards No. 2l2, No. 2l9, and No. 30l] do not specify a height adjustment because almost all vehicles have a single, set adjustment. . . . After careful consideration, it is the agency's position that such a vehicle capable of variable height adjustment would have to comply with the vehicle adjusted to any position that is possible. This is true because the vehicle could be driven on the highway, for example, even if it were adjusted to the off-road position. Consequently, it is important that the vehicle comply with the standards in all positions. You noted that while suspension height could be adjusted by the driver for the system discussed in the agency's previous interpretation, the active suspension system you are currently considering would use an on-board electronic controller to select suspension height, and suspension height would not be adjustable by the driver. Consequently, according to your letter, only one unique set of suspension height parameters is possible for a given vehicle speed and loading condition as is the case with conventional suspension systems. You stated that because it is possible to determine exactly what the intended suspension height should be for a given situation, it is Mazda's opinion that the test vehicle should be tested at the intended suspension height given the specified speed and loading conditions. You also stated that, using an "intended purpose" argument, Mazda concludes that the requirements of the three standards are to be met only when the vehicle's ignition is "on." You then asked whether these suggested interpretations are correct. Standard No. 2l2 specifies windshield retention requirements that must be met in a specified frontal crash test at any impact speed up to and including 30 mph. Similarly, Standard No. 2l9 specifies windshield zone intrusion requirements that must be met in a specified frontal crash test at any impact speed up to and including 30 mph. Standard No. 30l specifies fuel system integrity requirements for several specified crash tests. These include a frontal crash test similar to those in Standards No. 2l2 and No. 2l9. Requirements for this test must be met at any impact speed up to and including 30 mph. Other tests include a rear moving barrier crash test, a lateral moving barrier crash test, and a static rollover test. We agree that the requirements of Standards No. 2l2, No. 2l9, and No. 30l need not be met for vehicle heights that only occur when the engine is not on, since the requirements are only relevant in situations where the vehicle is operating. Looking at the three standards as a whole, we believe it is clear that, for the frontal tests specified by the three standards, NHTSA decided to limit the standards' evaluation of safety performance to how vehicles perform in impacts of 30 mph or less, even though the requirements have relevance at higher speeds. It is our interpretation that the frontal crash test requirements specified by these standards need to be met at all suspension heights that can occur at speeds of 30 mph or less, with the vehicle operational. It is also our interpretation that the crash test requirements need to be met only at suspension heights that can occur at the speed used in the crash test. We reach a different conclusion for Standard No. 30l's other crash test requirements. These requirements are relevant at all vehicle speeds and suspension heights. Moreover, NHTSA has not decided to limit the standard's evaluation of these aspects of safety performance to how vehicles perform at certain limited speeds. It is our interpretation that these crash test requirements must be met at all suspension heights that can occur with the vehicle operational. Part 58l Bumper Standard In asking about the Part 58l Bumper Standard, you noted that NHTSA has previously issued several interpretations of how the standard applies to vehicles with adjustable height suspension systems. In a letter to Subaru dated May 6, l986, NHTSA stated the following: Given the absence of a specific test condition concerning suspension height, it is our interpretation that a vehicle must be capable of meeting the standard's damage criteria at any height position to which the suspension can be adjusted. There is no language in the test requirements of the standard limiting their applicability to "the manufacturer's nominal design highway adjusted height position." This interpretation is consistent with the purpose of the Bumper Standard, set forth in section 58l.2, to reduce physical damage to the front and rear ends of a passenger motor vehicle from low speed collisions. If a vehicle's suspension could be adjusted so that its bumper height resulted in bumper mismatch with other vehicles in the event of low speed collisions, the reduction in physical damage attributable to the Bumper Standard would be defeated in whole or part. In another letter, dated February l2, l985, NHTSA stated that a vehicle is "required to meet the pendulum test of Part 58l in any vehicle use scenario in which the vehicle operates, and the barrier test of Part 58l when the engine is idling." You suggested, for the barrier test, that the agency's May l986 interpretation may be inappropriate for your active suspension system, since your system provides for only one suspension height when the engine is idling. You also suggested, for the pendulum test, that these interpretations seem to be in conflict with the Bumper Standard's stated purpose to reduce physical damage to motor vehicles in low speed collisions. We assume that you are referring to the fact that your suspension system has heights that occur only at speeds greater than 35 mph. You then requested that NHTSA provide an interpretation of Part 58l with respect to your system. In addressing how Part 58l applies to vehicles equipped with an active suspension system, I will address separately the standard's barrier and pendulum tests. For the barrier test, a vehicle must meet specified damage criteria after an impact into a fixed barrier that is perpendicular to the line of travel of the vehicle, at 2.5 mph. Section 58l.6 sets forth conditions applicable to bumper testing. Under section 58l.6(c), at the onset of a barrier impact, the vehicle's engine is operating at idling speed. Looking at the Bumper Standard as a whole, we believe it is clear that NHTSA decided to limit the barrier test's evaluation of bumper performance to how vehicles perform in 2.5 mph frontal impacts, even though the requirements have relevance at lower and higher speeds and when the vehicle is nonoperational. It is our interpretation that the barrier test requirements specified by this standard need to be met at all suspension heights that can occur at 2.5 mph. We reach a different conclusion for the pendulum test, which serves the purpose of creating a bumper height requirement. This requirement is relevant at all vehicle speeds and suspension heights, and when the vehicle is nonoperational. I note that while Mazda is correct that the Bumper Standard's stated purpose is to reduce physical damage to motor vehicles in low speed collisions, NHTSA has justified the bumper height requirement on safety concerns related to "higher speed collisions." In proposing Standard No. 2l5, the predecessor of Part 58l, the agency stated: . . . in higher speed collisions the tendency of a bumper to override another or to ride under or over a guardrail creates hazards for vehicle occupants. Vehicles with interlocking bumpers block traffic and expose their occupants to considerable danger, particularly if they attempt to get out to unlock bumpers. By overriding or underriding a guardrail, a bumper may strike a supporting post, or similar fixed object, with serious consequences for the vehicle and its occupants. 35 FR l7999, November 24, l970. The relevance of the bumper height requirement to nonoperational situations is also clear, e.g., to help protect parked cars. Moreover, NHTSA has not decided to limit the bumper height requirement to how vehicles perform at certain limited speeds. It is our interpretation that the pendulum test requirements must be met at all suspension heights that can occur, regardless of vehicle speed or whether the ignition is turned on. This interpretation is consistent with an October l8, l978 letter to Nissan, in which NHTSA addressed how the pendulum test applies to vehicles equipped with height control systems, including automatic height control systems. Among other things, the agency stated the following: . . . There is no language in the pendulum test requirements of the standard which would limit their applicability to only the ignition-on or ignition-off situation or to the recommended driving position for normal roadways. The vehicle must be capable of meeting the pendulum test requirements at all stable bumper heights possible at unloaded vehicle weight. Thus, in the situations described in Question l and 2 of your letter, in which an automatic height control system is employed, the vehicle must comply with the pendulum test requirements in both the ignition-on and ignition-off positions . . . . I note that one of our past letters, a December 24, l984 letter addressed to Porsche, appears to suggest that the pendulum test must be met in any setting in which the system operates "when the engine is idling." This might be read to suggest that the pendulum test need not be met when the vehicle is nonoperational. However, this interpretation cited section 58l.6(c) in concluding that the engine is idling during Part 58l testing. Section 58l.6(c) applies only to the barrier test and not the pendulum test. We therefore consider this interpretation to be incorrect to the extent that it is inconsistent with the analysis presented above. Sincerely, Paul Jackson Rice Chief Counsel ref:l08#lll#204#208#2l2#2l9#30l#58l d:l0/2/90 | 1989 | 
| ID: 05-009256drnOpenMs. Julie Laplante Les Entreprises Corbeil 830, 12 ime Avenue Laurentides (Qubec) J5M 2V9 CANADA Dear Ms. Laplante: This responds to your faxed letter asking how wheelchair weights are taken into consideration in calculating the gross vehicle weight rating (GVWR) of a school bus manufactured in two or more stages. You ask several questions as a manufacturer of such a school bus. Our responses are based on our understanding of your questions and the facts presented in your letter. Some background information might be helpful. Under the National Traffic and Motor Vehicle Safety Act (49 U.S.C. 30101 et seq.) and the National Highway Traffic Safety Administration (NHTSAs) regulations (49 CFR Part 567, Certification), each vehicle manufacturer must certify that each new vehicle complies with applicable Federal motor vehicle safety standards. As part of the certification, the manufacturer assigns a GVWR to the vehicle. GVWR is defined at 49 CFR Part 571.3, Definitions, as: the value specified by the manufacturer as the loaded weight of a single vehicle. The GVWR informs vehicle owners how heavily the vehicle may safely be loaded. NHTSA expects the GVWR to reflect a manufacturers good faith evaluation of the vehicles size, weight and load carrying capacity. The only express regulatory limitation on the assignment of GVWR is set forth in NHTSAs certification regulation, which states that the assigned GVWR shall not be less than the sum of the unloaded vehicle weight, rated cargo load, and 150 pounds times the vehicles designated seating capacity. However, for school buses the minimum occupant weight allowance shall be 120 pounds. (49 CFR 567.5(c)(5), Requirements for   manufacturers of vehicles manufactured in two or more stages. An identical provision is set forth in 567.4(g)(3) for vehicles manufactured in a single stage.)[1] With this background information, I will now address your questions as we understand them. Question No. 1. [Does] a wheelchair position ha[ve] the same weight [as] a designated seating capacity [sic]? We understand you to ask whether the weight of the wheelchair is included in the minimum occupant weight allowance specified in 49 CFR 567.5(c)(5). The answer is no. The weights of wheelchairs (because they are taken in and out of the school bus) would be considered part of the rated cargo load. When calculating the vehicles GVWR, the occupant weight allowance is a minimum of 120 pounds times the designated seating positions of the school bus, or 150 pounds times the designated seating positions of a bus. The weight of the wheelchair would be considered separate from the occupant weight allowance. Thus, when calculating the vehicles GVWR, the combined weight for occupants plus the unloaded vehicle weight plus the rated cargo load (which would include the weight of the wheelchairs) would be added together. (Unloaded vehicle weight means the weight of a vehicle with maximum capacity of all fluids necessary for operation of the vehicle, but without cargo, occupants, or accessories that are ordinarily removed from the vehicle when they are not in use. 49 CFR 571.3.) Question No. 2. If the answer is yes on question #1, do I have to calculate 150 pounds for a bus and/or 120 pounds for a school bus or multifunction school activity bus? The answer to #1 above was no. The occupant weight allowances in 567.5(c)(5) pertain to the weights of the persons on the bus, not to the weights of the wheelchairs. Question No. 3. If the answer is yes on question #1, do I have to add the weight of a passenger on top of the wheelchairs weight? See answers above. Question No. 4. Since there exists many types of wheelchairs (manually operated and self-propelled models), do we have the responsibility, as a manufacturer, to know exactly which kind of wheelchair will be used in a specific bus in order to calculate the GVWR? The GVWR must not be less than the sum of the unloaded vehicle weight, rated cargo load, and a minimum of 120 pounds times the vehicles designated seating capacity. The weight of the wheelchairs would be considered part of the rated cargo load. The rated cargo load on which you base the GVWR rating should not be less than what you can reasonably expect the user to use on your vehicle. See also answers to #5 and #6 below. 
 Question No. 5. Do we have the choice between two wheelchair weights? (Example: 120 pounds for a wheelchair location in a school bus-manually operated/X [sic] pounds for a wheelchair location in a school bus self-propelled). If it is reasonable to expect that the user will load the school bus with certain types of wheelchairs, including self-propelled (motorized) ones that are more massive than manual wheelchairs, the GVWR should account for the weight of the motorized wheelchairs. That the bus would carry self-propelled wheelchairs during its service life does not seem an unreasonable expectation. It is your responsibility to select a chassis with sufficient load ratings that will accommodate the weight of the vehicle. Question No. 6. If the answer is yes to question number 5, what would be the weight of a self-propelled wheelchair? We cannot answer this question for you. It is your responsibility as a manufacturer to evaluate the weights of the wheelchairs. The rated cargo load must not be less than what can reasonably be expected to be used on the school bus. If you have any further questions, please contact Dorothy Nakama of my staff at (202) 366-2992. Sincerely, Anthony M. Cooke Chief Counsel #ref:567 NCC-112:DNakama 3/2/06:revisedDfujita4/19/06:62992:OCC#05-009256 S:\INTERP\567\05-009256drn.doc cc:NCC-112, subj/chron, DN, NVS-100, NVS-200, Interps: 567, Redbooks (2) [1] Because you ask about school buses, we also draw your attention to our regulation defining the term designated seating position (49 CFR 571.3). The regulation specifies that: For the sole purpose of determining the classification of any vehicle sold or introduced into interstate commerce for purposes that include carrying students to and from school or related events, any location in such vehicle intended for securement of an occupied wheelchair during vehicle operation is regarded as four (4) designated seating positions. This provision was adopted to ensure that smaller school buses remain classified as school buses, and thus subject to the school bus safety standards, when seats are removed to install wheelchair securement positions. | |
| ID: nht76-2.28OpenDATE: 10/08/76 FROM: AUTHOR UNAVAILABLE; S. P. Wood for F. Berndt; NHTSA TO: American Honda Motor Co., Inc. TITLE: FMVSS INTERPRETATION TEXT: This is in reply to your letter of September 23, 1976, asking for an interpretation of the spacing requirements for motorcycle turn signal lamps specified in Table IV of Motor Vehicle Safety Standard No. 108. Standard No. 108 requires that motorcycle turn signal lamps be located so that their edges are at least 4 inches from the edge of the headlamps (on the front) and tail or stop lamps (on the rear). You have asked for confirmation "that the minimum separation distance is measured between the edges of the illuminated lenses of the respective lamps on a line passing through each lamp . . . rather than being measured on a horizontal line between two planes touching the edges of the illuminated lenses". This will confirm your interpretation that the minimum separation distance is to be measured at the point where the edges of the two lamps are closest to each other. | 
Request an Interpretation
You may email your request to Interpretations.NHTSA@dot.gov or send your request in hard copy to:
The Chief Counsel
National Highway Traffic Safety Administration, W41-326
U.S. Department of Transportation
1200 New Jersey Avenue SE
Washington, DC 20590
If you want to talk to someone at NHTSA about what a request for interpretation should include, call the Office of the Chief Counsel at 202-366-2992.
Please note that NHTSA’s response will be made available in this online database, and that the incoming interpretation request may also be made publicly available.