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: aiam0591OpenMr. Jerry Warner, Manager, Foam Sales & Engineering, Keyston Brothers, 1000 Brannan Street, San Francisco, CA, 94103; Mr. Jerry Warner Manager Foam Sales & Engineering Keyston Brothers 1000 Brannan Street San Francisco CA 94103; Dear Mr. Warner: This is in reply to your letter of February 9, 1972, concerning th application of Motor Vehicle Safety Standard No. 302, 'Flammability of Interior Materials,' to an interior upholstered panel that you manufacture. You state that the panel is made up of a vinyl surface, a self-extinguishing foam, and a backing, and that the three materials must be tested as a single unit, or separately.; Paragraph S4.2 of Standard No. 302 specifies as follows:>>>S4.2 Th portions of the components that shall meet the requirements of S4.3 are all of the following:; (a) The surface material taken separately if it is not bonded, sewed o mechanically attached to underlying material.; (b) A composite consisting of the surface material bonded, sewed o mechanically attached to underlying material, if such a composite is used in the component.; (c) Padding and cushioning materials taken separately, if thos materials are not bonded, sewed or mechanically attached to surface materials.<<<; Under the language of S4.2, your surface material, and the underlyin foam should be tested as a composite pursuant to subparagraph (b). If the backing is considered a padding or cushioning material, it should be tested separately pursuant to subparagraph (c).; A notice of proposed rulemaking which would amend paragraph S4.2 wa published May 26, 1971 (36 F.R. 9565), and a copy is enclosed for your information. We expect that a final rule based on this proposal will be published in the near future. Under the wording of the proposal your material would be tested under subparagraph (b) to a depth of 1/2 inch, and padding and cushioning material would be tested again under subparagraph (c).; We are pleased to be of assistance. Yours truly, Richard B. Dyson, Assistant Chief Counsel |
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ID: aiam2731OpenMr. R. W. Hildebrandt, Group Director of Engineering, The Bendix Corporation, 901 Cleveland Street, Elyria, OH 44035; Mr. R. W. Hildebrandt Group Director of Engineering The Bendix Corporation 901 Cleveland Street Elyria OH 44035; Dear Mr. Hildebrandt: This responds to Bendix Corporation's November 9, 1977, request fo confirmation that S5.6.4 of Standard No. 121, *Air Brake Systems*, does not prohibit the use of a two-valve sequential means to release the parking brakes on a towed vehicle.; I have enclosed for your information two interpretations that addres this question, stating that a two- valve sequential release is permissible under S5.6.4. I have also enclosed a copy of an outstanding rulemaking proposal that would standardize the parking brake control as specified in the Society of Automotive Engineers Recommended Practice J680b. I am unable to advise you whether the National Highway Traffic Safety Administration intends to make final this proposal.; I would also like to remind you of the requirement in S5.6.4 tha '[t]he control shall be identified in a manner that specifies the method of control operation.' So long as different control arrangements are used, it is critical that the means of operation be clearly marked.; Joseph J. Levin, Jr. |
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ID: aiam0418OpenMr. A.J. Macho, Holan Company, 4100 W. 150th Street, Cleveland, OH 44135; Mr. A.J. Macho Holan Company 4100 W. 150th Street Cleveland OH 44135; Dear Mr. Macho: This is in reply to your letters of June 30 and August 2 on the subjec of the applicability of Standard No. 210 to multipurpose passenger vehicles, trucks, and buses as amended by notice of March 4, 1971 (36 F.R. 4291). The standard applies to these vehicles effective July 1, 1971, even though the heading published in the *Register* refers only to passenger cars. The application of the standard is controlled by the application section, S2, and not by the heading of the standard. The heading only reflects the substance of the application section and should automatically change whenever the application is changed. Through oversight, the *Federal Register* was given no instructions as to heading changes, and therefore inserted the old heading into the March 4 notice. Since the heading has no substantive role, and since the amendment is only in effect until the revised Standard No. 210 becomes effective January 1, 1972, we have not requested the *Federal Register* to alter the heading.; I hope this is responsive to your question. Sincerely, Robert L. Carter, Acting Associate Administrator, Moto Vehicle Programs; |
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ID: aiam1393OpenMr. Lee Moses, Trailer Coach Association, 3855 East LaPalma Avenue, Anaheim, CA, 92806; Mr. Lee Moses Trailer Coach Association 3855 East LaPalma Avenue Anaheim CA 92806; Dear Mr. Moses: This is in response to your telephone request of February 6, 1974 concerning the application of Standard No. 302, *Flammability of Interior Materials.*; The standard applies to passenger cars, multipurpose passenge vehicles, trucks, and buses. It does not apply to trailers, the vehicle category which includes mobile homes and other towed recreational vehicles, but it does apply to motor homes and to those campers that are constructed on new chassis. Accordingly, any of the components listed in paragraph S4.1 that are installed in the occupant compartments of the motor vehicles to which the standard is applicable must meet the standard's requirements.; You also asked whether a State may have a motor vehicle safety standar applicable to vehicles covered by a Federal standard that differs from the requirements of the Federal standard. The answer is no. Under the preemption provision of the National Traffic and Motor Vehicle Safety Act, section 103(d), 15 U.S.C. 1392(d), State motor vehicle requirements, if any, have to be identical to the requirements of the Federal standard. Any differing requirements would be void.; Yours truly, Richard B. Dyson, Assistant Chief Counsel |
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ID: aiam2114OpenNaoyoshi Suzuki, Nissan Motor Co., Ltd., P.O. Box 1606, Englewood Cliffs, NJ 07632; Naoyoshi Suzuki Nissan Motor Co. Ltd. P.O. Box 1606 Englewood Cliffs NJ 07632; Dear Mr. Suzuki: This is in response to your letter of October 15, 1975, in which yo request an interpretation of paragraph S7.1.3 of Standard No. 301, as to whether it is permissible to stop an electric fuel pump prior to the rollover test.; Paragraph S7.1.3 provides that 'If the vehicle has an electricall driven fuel pump that normally runs when the vehicle's electrical system is activated, it is operating at the time of a barrier crash.' The static rollover test specified by S6.4 is not a barrier crash, and therefore is not covered by S7.1.3. In the amendments to Standard No. 301 published on October 15, 1975 (40 FR 48352), the addition of the phrase 'In meeting the requirements of S6.1 through S6.3' to S7.1.3 clarifies the intent of the agency not to require that an electric fuel pump be operating at the time of the rollover test, because the rollover test is required by paragraph S6.4. Therefore, you may turn off the pump if it is still working at the time of the static rollover test.; Sincerely, Frank Berndt, Acting Chief Counsel |
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ID: aiam3069OpenMr. G. Frinken, Manager, Automotive Engineering Europe, Uniroyal European Tire Development Center, Uniroyal GMBH, Postfach 410, 5100 Aachen 1, West Germany; Mr. G. Frinken Manager Automotive Engineering Europe Uniroyal European Tire Development Center Uniroyal GMBH Postfach 410 5100 Aachen 1 West Germany; Dear Mr. Frinken: This is in response to your letter of July 20, 1979, concerning th Uniform Tire Quality Grading (UTQG) Standards (49 CFR 575.104). You ask whether it is permissible under the regulation to mold UTQG grades on only one sidewall of a tire and, in the case of a symmetrical black sidewall tire, whether the grades may be molded on the same sidewall as the tire identification number required by 49 CFR 574.5.; The UTQG Standards require that tire grades need be molded on only on sidewall of a tire. Since the regulation presently does not specify the sidewall on which tire grades must be molded, Uniroyal is legally permitted to mold UTQG grades on either sidewall of its tires. However, in order to facilitate consumer access to the grading information, the National Highway Traffic Safety Administration (NHTSA) encourages manufacturers to mold tire grades on the sidewall intended to be visible when the tire is mounted on a vehicle. NHTSA will monitor the placement of tire grades to determine whether further action is necessary to assure the accessibility of the grading information.; Sincerely, Frank Berndt, Chief Counsel |
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ID: aiam3068OpenMr. G. Frinken, Manager, Automotive Engineering Europe, Uniroyal European Tire Development Center, Uniroyal GMBH, Postfach 410, 5100 Aachen 1, West Germany; Mr. G. Frinken Manager Automotive Engineering Europe Uniroyal European Tire Development Center Uniroyal GMBH Postfach 410 5100 Aachen 1 West Germany; Dear Mr. Frinken: This is in response to your letter of July 20, 1979, concerning th Uniform Tire Quality Grading (UTQG) Standards (49 CFR 575.104). You ask whether it is permissible under the regulation to mold UTQG grades on only one sidewall of a tire and, in the case of a symmetrical black sidewall tire, whether the grades may be molded on the same sidewall as the tire identification number required by 49 CFR 574.5.; The UTQG Standards require that tire grades need be molded on only on sidewall of a tire. Since the regulation presently does not specify the sidewall on which tire grades must be molded, Uniroyal is legally permitted to mold UTQG grades on either sidewall of its tires. However, in order to facilitate consumer access to the grading information, the National Highway Traffic Safety Administration (NHTSA) encourages manufacturers to mold tire grades on the sidewall intended to be visible when the tire is mounted on a vehicle. NHTSA will monitor the placement of tire grades to determine whether further action is necessary to assure the accessibility of the grading information.; Sincerely, Frank Berndt, Chief Counsel |
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ID: aiam0443OpenMr. Kenneth H. Dickey, Electric Device Corporation, 266 Bradford Drive, Canfield, OH, 44406; Mr. Kenneth H. Dickey Electric Device Corporation 266 Bradford Drive Canfield OH 44406; Dear Mr. Dickey: This is in reply to your letter of September 1, 1971, to Mr. Dougla Toms, Administrator, National Highway Traffic Safety Administration, concerning your request for an interpretation relative to your safety backing system and the Federal Standards.; The use of your School Bus Safety Backing System is neither require nor prohibited in Federal Motor Vehicle Safety Standard No. 108 and the proposed Pupil Transportation Safety Standard. However, it would appear that the regulations of the individual States apply to the use of your system in those States.; Sincerely, E. T. Driver, Director, Office of Operating Systems, Moto Vehicle Programs; |
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ID: aiam2310OpenMr. T. Takeda, Manager, Automotive Lighting Engineering Dept., Stanley Electric Co., Ltd., 2-9-13, Nakameguro, Meguro-Ku, Tokyo 153, Japan; Mr. T. Takeda Manager Automotive Lighting Engineering Dept. Stanley Electric Co. Ltd. 2-9-13 Nakameguro Meguro-Ku Tokyo 153 Japan; Dear Mr. Takeda: This is in reply to your letter of April 20, 1976, asking for a amendment of S4.1.1.21 of Motor Vehicle Safety Standard No. 108 to allow a plus tolerance of 7.5 percent on maximum wattage requirements for Type 1A and 2A headlamps.; I enclose a copy of an interpretation furnished the General Electri Company which states that such a tolerance is allowed. However, to clarify our intent we plan to amend Standard No. 108 in the near future in the manner that you suggest.; Yours truly, Stephen P. Wood, Assistant Chief Counsel |
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ID: aiam0292OpenMr. Harold Vischer, Vice President, Bandag, Incorporated, 1056 Hershey Avenue, Muscatine, IA 52761; Mr. Harold Vischer Vice President Bandag Incorporated 1056 Hershey Avenue Muscatine IA 52761; Dear Mr. Vischer: This is in reply to your letter to Mr. Hartman concerning the tir identification and record keeping regulation (49 CFR Part 574) requesting that you be allowed to code by pressure chamber rather than by matrix.; Since the pressure chamber is used by Bandag to serve a purpose simila to the purpose served by the matrix in hot processing of retreaded tires, you may assign code numbers to your pressure chambers and use this code number in place of the matrix code number required by Part 574.; Sincerely, Rodolfo A. Diaz, Acting Associate Administrator, Moto Vehicle Programs; |
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.