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 |
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ID: nht91-6.32OpenDATE: October 23, 1991 FROM: Paul Jackson Rice -- Chief Counsel, NHTSA TO: Earl H. Kester -- President, Seatco TITLE: None ATTACHMT: Attached to letter dated 9-19-91 from Earl H. Kester to Paul Jackson Rice TEXT: This responds to your letter concerning requirements that apply to retail establishments that sell and install replacement seats on used vans and pickup trucks. You noted that a vehicle's seats affect its compliance with Federal Motor Vehicle Safety Standard No. 208, Occupant Crash Protection, and asked whether businesses which sell and install replacement seats are required by Federal law to use ones that enable the vehicle to continue to comply with that standard. As discussed below, the answer to our question is yes. The National Traffic and Motor Vehicle Safety Act specifies that vehicles must conform with all applicable safety standards up until the first purchase for purposes other than resale. After the first purchase, the vehicle is no longer required by Federal law to conform with all safety standards. However, section 108(a)(2)(A) of the Safety Act provides as follows: No manufacturer, distributor, dealer, or motor vehicle repair business shall knowingly render inoperative, in whole or part, any device or element of design installed on or in a motor vehicle or item of motor vehicle equipment in compliance with an applicable Federal motor vehicle safety standard . . . . In order to avoid violating this provision, a manufacturer, dealer, distributor, or repair business which removes and replaces a seat must use a replacement seat which enables the vehicle to continue to comply with Standard No. 208 and other safety standards for which the original seat was designed to ensure compliance. I note that the "render inoperative" provision does not require a company to test a vehicle after installation of a new seat to ensure that it continues to comply with all applicable standards. However, if an analysis of the replacement seat, as installed, indicates that the resulting vehicle would no longer comply with the requirements of Standard No. 208 and other relevant safety standards, the company could not legally perform such an installation. I hope this information is helpful. |
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ID: nht91-6.33OpenDATE: October 23, 1991 FROM: Paul Jackson Rice -- Chief Counsel, NHTSA TO: David L. Kulp -- Manager, Fuel Economy Planning & Compliance, Environmental and Safety Engineering Staff, Ford Motor Company TITLE: None ATTACHMT: Attached to letter dated 8-9-91 from David L. Kulp to Orron E. Kee (OCC 6441) TEXT: This responds to your letter to Mr. Orron Kee of this agency that asked whether, to comply with Corporate Average Fuel Economy (CAFE) reporting requirements, Ford must report off-highway data as listed, in 49 CFR S537.7(c)(5) for light trucks that otherwise come within the definition of light trucks at 49 CFR S523.5(a). As discussed below, the answer to your question is no. Under S523.5, a light truck is an automobile other than a passenger automobile which is either designed to perform at least one of a number of functions listed in S523.5(a) or is designed for off-highway operation as described in S523.5(b). Since the characteristics described in (a) and (b) are not mutually exclusive, some vehicles are considered light trucks under both (a) and (b). Section 537.7(c) (5) provides that for each model type of an automobile which is classified as an automobile capable of off-highway operation under Part 523, i.e., S523.5(b), certain data relevant to that classification must be included in a manufacturer's fuel economy reports. Your letter raises the issue of whether this information must be reported for vehicles which are considered light trucks under S523.5(a) but which would also be considered light trucks under S523.5(b). It is our opinion that S537.7(c)(5)'s requirement to report data relevant to the classification of a vehicle as capable of off-highway operation applies only for vehicles which are considered light trucks solely on that basis and not to vehicles that are otherwise considered light trucks under S523.5(a). |
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ID: nht91-6.34OpenDATE: October 23, 1991 FROM: Paul Jackson Rice -- Chief Counsel, NHTSA TO: Martin L. Marinoff TITLE: None ATTACHMT: Attached to letter dated 7-30-91 from Martin L. Marinoff to NHTSA (OCC 6511) TEXT: This responds to your letter asking about Federal Motor Vehicle Safety Standard No. 105, Hydraulic Brake Systems. You stated that you believe the standard requires vehicles to have a warning light system that indicates loss of pressure or low fluid level in the braking system and asked if this belief is correct. Your understanding about Standard No. 105 is correct. I have enclosed a copy of that standard for your information. The requirements for brake system indicator lamps are set forth at section S5.3 of the standard. |
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ID: nht91-6.35OpenDATE: October 23, 1991 FROM: Paul Jackson Rice -- Chief Counsel, NHTSA TO: Phil Lanam -- City of Ukiah Fire Department TITLE: None ATTACHMT: Attached to letter dated 8-19-91 from Phil Lanam to Taylor Vinson (OCC 6412); Also attached to letter dated 3-4-80 from Frank Berndt to Joe Cain TEXT: This responds to your letter about the installation of new standard "S" cam air brakes on a 1978 Ford truck. You explained that because you were having problems with the vehicle's anti-skid system, you were planning to replace it with a new braking system. As discussed below, Federal law does not prohibit you or a commercial business from replacing the anti-skid system with a standard current brake system. 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 National Highway Traffic and Motor Vehicle-Safety Act (Safety Act), it is the responsibility of the manufacturer to ensure that its motor vehicles or items of equipment comply with all applicable standards. The following represents our opinion based on the facts provided in your letter. The agency has issued Federal motor vehicle safety standard (FMVSS) No. 121, Air Brake Systems. That standard applies to almost all new trucks, buses, and trailers equipped with air brake systems. As originally manufactured, Ford, as the manufacturer was required to certify that the truck satisfied the requirements of all applicable safety standards. Among other things, the vehicle's brakes would have been required to comply with FMVSS No. 121. The National Traffic and Motor Vehicle Safety Act specifies that vehicles must conform with all applicable safety standards up until the first purchase for purposes other than resale. After the first purchase, the vehicle is no longer required by Federal law to conform with all safety standards. However, the Safety Act includes a provision that prohibits any manufacturer, distributor, dealer, or motor vehicle repair business from "rendering inoperative" any device or element of design installed in or on a vehicle in compliance with an applicable safety standard. The render inoperative provision does not apply to modifications made by the owner of a vehicle.
The issue of whether a late 1970's antilock system for heavy vehicles can be disconnected by a commercial business is a special case under the render inoperative provision, since those antilock systems were used by some manufacturers to comply with certain requirements of FMVSS No. 121 that were later invalidated by a court decision. I have enclosed a copy of a March 4, 1980 letter which addresses that issue. Based on this letter, a commercial business could replace the anti-skid system with a standard current brake system without violating the render inoperative provision. I hope this information is helpful. If you have any further questions, please feel free to contact Marvin Shaw of my staff at this address or by telephone at (202) 366-2992. |
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ID: nht91-6.36OpenDATE: October 23, 1991 FROM: Paul Jackson Rice -- Chief Counsel, NHTSA TO: Al Lipinski -- President, Mini-Max TITLE: None ATTACHMT: Attached to letter dated 9-18-91 from Al Lipinski to Messrs. Hall, Jackson, and Rice, NHTSA (OCC 6509) TEXT: This responds to your letter asking what the dynamic testing requirements are for alterers of certified vehicles. You stated that you are a small conversion company of walk in van type light trucks, that you do not alter anything forward of the B pillar of the previously certified vehicle, and that the crash protection system installed by the original manufacturer is not disturbed. You also stated that you affix an additional label stating the vehicle alterations conform to all applicable Federal motor vehicle safety standards. I am pleased to have this opportunity to explain our regulations to you. Some background information on Federal motor vehicle safety laws and regulations may be helpful. As you are aware, our agency is authorized, under the National Traffic and Motor Vehicle Safety Act (15 U.S.C. S1381 et seq.; Safety Act), to issue safety standards applicable to new motor vehicles and certain items of motor vehicle equipment. NHTSA, however does not approve motor vehicles or motor vehicle equipment, nor do we endorse any commercial products. Instead, the Safety Act establishes a "self-certification" process under which each manufacturer is responsible for certifying that its products meet all applicable safety standards. Under NHTSA's certification regulation, an alterer is a person who alters previously certified vehicles by means other than the addition, substitution, or removal of readily attachable components, or minor finishing operations, or in such a manner that the vehicle's stated weight ratings are no longer valid, before the first purchase of the vehicle in good faith for purposes other than resale. An alterer is required to certify that every vehicle it alters continues to comply with all applicable safety standards after the alterer has performed its operations on the vehicle. See 49 CFR Part 567.7. Alterers must have some independent basis for their certification that an altered vehicle continues to comply with all applicable safety standards. This does not, however, mean that an alterer must conduct crash testing, even with respect to standards that include dynamic test requirements. Certifications of continuing compliance for altered vehicles may be based on, among other things, engineering analyses, computer simulations, actual testing, or instructions for alteration voluntarily provided by the original vehicle manufacturer in a "body builder's guide." Your letter suggests that you are primarily concerned about the dynamic test requirements of Standard No. 208 Occupant Crash Protection. I note that in establishing that standard's dynamic test requirements for light trucks, NHTSA made those requirements optional for walk in van type trucks. See S4.2.2 of Standard No. 208. Thus, the walk in van type trucks you alter were not required to comply with the Standard No. 208's dynamic test requirements and may not have been designed to do so. You can find out by contacting the original vehicle manufacturer. I hope this information is helpful. |
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ID: nht91-6.37OpenDATE: October 23, 1991 FROM: Paul Jackson Rice -- Chief Counsel, NHTSA TO: None TITLE: None ATTACHMT: Attached to letter dated 9-6-91 to Taylor Vinson TEXT: This responds to your letter of September 6, 1991, to Mr. Vinson, asking whether a vehicle you are developing would be classified as a multipurpose passenger vehicle for the purposes of the Federal motor vehicle safety standards. I am pleased to be able to explain our law and regulations for you. At the outset, I would like to make clear that the National Traffic Motor Vehicle Safety Act (15 U.S.C. 1381 et seq.) places the responsibility for classifying a particular vehicle in the first instance on the vehicle's manufacturer. For this reason, NHTSA does not approve or endorse any vehicle classification before the manufacturer itself has classified a particular vehicle. NHTSA may reexamine the manufacturer's classification during the course of any enforcement actions. We will, however, tentatively state how we believe we would classify this vehicle for the purposes of our safety standards. It is important that you understand that these tentative statements of classification are based entirely on our understanding of the information presented in your letter to us. These tentative statements about the vehicle's classification may change after NHTSA has had an opportunity to examine the vehicle itself or otherwise acquire additional information about the vehicle. With those caveats, we believe that the vehicle referenced in your letter could be classified as a multipurpose passenger vehicle for the purposes of our safety standards. The term "multipurpose passenger vehicle" is defined in 49 CFR S571.3 as "a motor vehicle with motive power, except a trailer, designed to carry 10 persons or less which is constructed either on a truck chassis or with special features for occasional off-road operation." In your letter, you state that the vehicle's chassis should be considered a truck chassis because it "was originally designed to provide cargo-carrying capability as well as to permit rough road and off the road vehicle operation." Additionally, you state that the approach and departure angles and the running clearance dimensions for this vehicle are more similar to other vehicles which have been classified by their manufacturers as multipurpose passenger vehicles than vehicles that have been classified as passenger cars. Based upon this description, it appears to us that this vehicle could be classified as a multipurpose passenger vehicle. I hope you find this information helpful. The version of your letter that has been placed in the public docket has all the information for which you requested confidential treatment deleted from it. If you have further questions, please contact Mary Versailles of my staff at this address or by telephone at (202) 366-2992. |
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ID: nht91-6.38Open
DATE: October 23, 1991 FROM: Paul Jackson Rice -- Chief Counsel, NHTSA TO: Gary Starr -- Solar Electric Engineering TITLE: None ATTACHMT: Attached to letter dated 9-9-91 from Gary Starr to NHTSA TEXT: The agency recently received an unsigned petition dated September 9, 1991, in which Solar Electric Engineering asked for a temporary exemption from the Federal motor vehicle safety standards. The petition named you as the company's contact. According to the petition, Solar Electric's product "is a standard vehicle manufactured under NHTSA standards and originally certified by the O.E.M. . . . ." A NHTSA engineer has suggested to the company that "the NHTSA may not require the exemption application." because the vehicle is "altered." This comment relates to the obligations imposed by 49 CFR Sec. 567.7 on a person who alters, in more than minor respects, a previously certified vehicle before its sale to its first owner. Such an alterer is required to affix his own certification label stating that the vehicle as altered conforms to all applicable Federal motor vehicle safety standards. Solar Electric appears hesitant to certify compliance with all standards, and, given the magnitude of conversion from internal combustion power to electric power, NHTSA would regard it as a "manufacturer" who is eligible to file a temporary exemption petition.
However, before a petition can be processed, it must meet the agency's procedural requirements (in this instance, 49 CFR Sec. 555.5(b) and 555.6(c)). Although Solar Electric's petition attempts to do so, it falls short in several respects. Its most major failure is that does not state with specificity the standards for which exemption is requested, as required by Sec. 555.5(b)(4). Although paragraph 2) i) of your letter states that the vehicle would "perhaps" differ with Standards Nos. 103, 105, 208 "specifically part 572 (Anthropomorphic Test Dummy), . . . and perhaps other standards which are unknown at this time or would not apply to an electric vehicle", this is too indefinite to fulfill the requirements of Sec. 555.5(b)(4). Further, to the extent that your paragraph 2) i) is intended to fulfill the requirements of Sec. 555.6(c)(2)(i), it fails to provide the "detailed description" of how the motor vehicle, if exempted, would differ from one that complies with the standard." We recommend, therefore, that Solar Electric review the Federal motor vehicle safety standards with a view towards amending its petition in accordance with our comments. In addition, section 555.6(c)(2)(iv) requires a petitioner to provide reasons why an exemption from each standard requested "does not unreasonably degrade the safety of the vehicle." When Solar Electric has determined the standards from which it requests exemption, its supplementary petition should contain arguments addressing this point. With the thought that it may assist you, I enclose a copy of a Federal Register notice that discusses the petition of another vehicle converter, and the way that it presented the information required by our regulations. Although the notice was published in 1975, our requirements have not changed since that time. We would also appreciate knowing the make, model, and model year of the vehicles intended for conversion. Please also ensure that the amendment to the petition is signed by a company official. When we have received information sufficient to meet our procedural requirements, we shall be pleased to consider the petition further. If you have any questions, Taylor Vinson of my staff will be pleased to answer them (202-366-5263).
Enclosure Copy of the Federal Register, volume 40, number 120 (6/20/75) titled Electric Fuel Propulsion Corporation; Petition for Temporary Exemption From Federal Motor Vehicle Safety Standards (Text omitted) |
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ID: nht91-6.39OpenDATE: October 24, 1991 FROM: Sue Ellen Russell -- Brand & Lowell TO: Paul Jackson Rice -- Chief Counsel, NHTSA COPYEE: Robert Hellmuth; Robert Krauss; Harry Thompson; Z Taylor Vinson TITLE: None ATTACHMT: Attached to letter dated 1/14/92 from Paul Jackson Rice to Sue Ellen Russell (A39; Std. 207; Std. 210) TEXT: This firm represents the Glaval Corporation, a company engaged in the business of van conversions. Glaval recently notified NHTSA of its intention to conduct a notification and remedy campaign to respond to an apparent noncompliance with the safety belt anchorage strength requirements as they apply to the rear bench set in Glaval vans. These seats contain three designated seating positions, and each seat belt anchorage is mounted on the seat, not the floor. In the course of evaluating potential remedies to ensure their compliance with the requirements of the standard, we became aware of a recent interpretation of FMVSS 210 (S4.2) issued to R.W. Schreyer of the Transportation Manufacturing Corporation (April 9, 1990). A copy is enclosed for your convenience. In this interpretation, the agency stated that ONLY FLOOR-MOUNTED anchorages common to a single seat and governing "adjacent seating positions" would be tested simultaneously for compliance with FMVSS 210. The letter reiterates that "Even those anchorages common to one occupant seat would be tested simultaneously only if the anchorages were floor-mounted." This interpretation raises several questions, because the Glaval bench seat in NHTSA's test was subjected to simultaneous loading of the anchorages for all three seating positions, although none of these anchorages is floor-mounted. Glaval's testing, conducted in accordance with the published test procedures in order to replicate the NHTSA test, also loaded the three seating positions simultaneously. Glaval's questions are: 1. Consistent with the Schreyer interpretation, should the seat-mounted anchorages of the Glaval bench seat have been loaded sequentially in NHTSA's test? If so, how does NHTSA's test on the Glaval bench seat, where the loads were applied simultaneously, affect NHTSA's tentative conclusion of noncompliance? 2. Since Standard 207 requires simultaneous loading of the forces required by Standard 207 along with those required by Standard 210, does the Schreyer interpretation mean that, for a bench seat with seat-mounted anchorages, the proper loading for a test pursuant to FMVSS 207 should be 20 times the seat weight, plus the proper load for one designated seating position on the bench seat? We look forward to Your early response to these questions, as they will affect Glaval's on going work on this issue. Attachment Letter dated 3/5/90 from R.W. Schreyer, of Transportation Manufacturing Corporation to Harry Thompson, of NHTSA. (Text omitted) |
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ID: nht91-6.4OpenDATE: September 18, 1991 FROM: Robert A. Nordmeyer -- Nordic Associates TO: NHTSA Administrator, Rule Making Department TITLE: None ATTACHMT: Attached to letter dated 11-13-91 from Paul Jackson Rice to Robert A. Nordmeyer (A38; Std. 201; Std. 302) TEXT: We are developing an after market sun visor for a client (illustrations attached). Would you please advise me if there are any federal sanctions governing the design, maximum viewing area that may be blocked by such a device, minimum force required to secure the visor in the extended or retracted position and minimum amount of padding on edges of the visor. If you have any questions regarding this issue, I can be reached by phone at (818) 347-1597 or Fax (818) 883-3342.
ATTACHMENT Six drawings of sun visors. (Graphics omitted) |
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ID: nht91-6.40OpenDATE: October 25, 1991 FROM: Russell J. Eisert TO: Steve Kratze -- NHTSA TITLE: None ATTACHMT: Attached to letter dated 2/18/92 from Paul Jackson Rice to Russell J. Eisert (A39; Std. 208) TEXT: I am writing this with reference to the new laws that were passed pertaining to the conversion of vans. I am a quadriplegic and have been trying to purchase a new van and have run into all kinds of problems. Because I drive from my wheelchair I do not want a seat put in on the drivers side. Also because I sit in the wheelchair a little bit higher than a normal seat I would like to have the roof cut out over the front to give me a couple of inches more headroom. The other problem is because I need space to maneuver inside the van I would like to have the rear seats and folding bed moved to the rear of the side door. I have been driving my other vans with this arrangement since 1978 without any problems. The Chevy dealers and the Conversion people all tell me that this can not be done in 1992. American International Conversions said I would have to write to you and obtain a letter of waiver from you to cover these items so they can convert a van for me. I therefore respectfully request a letter of waiver from you to allow them to modify these three items for me. Your early response to this matter would be very much appreciated. If it would be possible, could you please fax a copy of the letter to American International Conversions, Fax# 813/586-6627. This would save a few days of mail time. Thank you very much for your consideration of this very disturbing problem. |
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.