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: aiam1111OpenMr. Wesley L. Barclift, State of Washington, Department of Motor Vehicles, Olympia, WA 98504; Mr. Wesley L. Barclift State of Washington Department of Motor Vehicles Olympia WA 98504; Dear Mr. Barclift: This is in reply to your letter of March 27, 1973, concerning th acceptability of the State of Washington title application form as a means of conforming to the Federal odometer disclosure requirements in new car transactions.; Although we are not anxious to increase the paper work burden in ne car transactions, without good reason, there have been indications of a variety of misleading practices involving new cars and we drafted the requirements to place new car transactions, with one exception, on the same footing as used car transactions. We would therefore urge that a full statement be given to new car purchasers, or at the least, that a statement containing the balance of the information required by section 580.4 be appended to the application form.; The exception is the transfer between dealers of a new car prior to it first sale to a customer. Your letter indicates that you may have overlooked this exception, which is found in section 580.5(b).; Sincerely, Lawrence R. Schneider, Chief Counsel |
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ID: aiam0044OpenMr. Arnold Hosbach, Ander-BTT Incorporated, East Tawas, MI 48730; Mr. Arnold Hosbach Ander-BTT Incorporated East Tawas MI 48730; Dear Mr. Hosbach: We are in receipt of your letter dated November 30, 1967, forwarded t us through the Michigan Department of State Police.; This letter is in answer to your inquiry as to whether your mobile hom or trailer house is required to comply with the Federal Motor Vehicle Safety Standards. From the brief description of your product we would state that your vehicle would fall into the category of the multi-purpose passenger vehicle.; Enclosed is a copy of the Initial Federal Motor Vehicle Safet Standards. Your attention is directed to Subpart B. This section indicates those safety standards which multi-purpose passenger vehicles are required to comply with.; Also enclosed is a notice published in the Federal Register date November 1, 1967, stating the Certification Requirement effective January 1, 1968.; If we can provide additional information, please feel free to contac this office.; Sincerely, Joseph R. O'Gorman, Acting Director, Office of Performanc Analysis; |
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ID: aiam3650OpenMr. Robert B. Wessel, Consus International, Inc., P.O. Box 594, Port Jefferson Station, NY 11776; Mr. Robert B. Wessel Consus International Inc. P.O. Box 594 Port Jefferson Station NY 11776; Dear Mr. Wessel: This is in response to your December 1, 1982, letter regarding warning device you plan to manufacture. The device is powered by 4 AA batteries, and has a light which can stay on continuously or can flash. You have asked whether the device complies with Federal Motor Vehicle Safety Standard 125.; Standard 125 applies to warning devices 'without self- contained energ sources.' The four batteries in your device which power the light would constitute such a source. Therefore, Standard 125 is inapplicable to your device.; If you have further questions on this matter, feel free to contact us. Sincerely, Frank Berndt, Chief Counsel |
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ID: aiam3064OpenMr. Gerhard O. Waizmann, Porsche, 818 Sylvan Avenue, Englewood Cliffs, NJ 07632; Mr. Gerhard O. Waizmann Porsche 818 Sylvan Avenue Englewood Cliffs NJ 07632; Dear Mr. Waizmann:#This is in response to your letter of May 25, 1979 requesting clarification of Federal Motor Vehicle Safety Standard No. 101- 80, *Controls and Displays*. You asked whether the rear window defogger switch, which emits a dim light for control location and a brighter light upon activation, is considered a control or a telltale.#Although the switch might be regarded as a control, telltale, or both, it is regulated as a control insofar as its illumination is concerned. Therefore, its illumination must be continuously variable as specified in S5.3.3 of the standard.#S5.3.3 provides that#>>>Each passenger car...manufactured with any control listed in S5.1 or in column 1 of Table 1, and each passenger car...with any display listed in S5.1 or in column 1 of Table 2, shall meet the requirements of this standard for the location, identification, and illumination of such control or display.<<<#The rear window defrosting and defogging system appears in the control list of S5.1 and in Table 1, but not in the display list of S5.1 or in Table 2. Therefore, the control illumination requirements of S5 apply to the defogging switch and the display illumination requirements do not.#If you have any further questions, please do not hesitate to write.#Sincerely, Frank Berndt, Chief Counsel; |
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ID: aiam1441OpenMr. Hayso Hirai, Technical Representative, MAZDA, 1444 McGaw Avenue, Irvine, California 92705; Mr. Hayso Hirai Technical Representative MAZDA 1444 McGaw Avenue Irvine California 92705; Dear Mr. Hirai: This is in reply to your letter of February 8, 1974, which requests review of your new accelerator system to determine compliance with Standard No. 124, 'Accelerator Control Systems.'; The NHTSA does not provide a technical review of a manufacturer' product nor certify that a particular design meets the requirements of a standard. That is the manufacturer's responsibility. We will interpret or clarify the meaning of the standard in response to specific questions.; We understand your question to be whether two springs surrounding spring guide and separated by a washer meet the stipulation in S5.1 of Standard No. 124 for '... at least two sources of energy ...' This arrangement of springs would be considered 'two sources of energy' within the meaning of the standard.; As you requested, the technical description has been held confidentia as a 'trade secret' and we are returning it to your herewith.; Yours truly, Richard B. Dyson, Assistant Chief Counsel |
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ID: aiam2642OpenMr. Robert Rubenstein, Chief Engineer, Alderson Research Laboratories, Inc., 390 Ludlow Street, Stamford, CT 06904; Mr. Robert Rubenstein Chief Engineer Alderson Research Laboratories Inc. 390 Ludlow Street Stamford CT 06904; Dear Mr. Rubinstein (sic): This responds to Alderson Research Laboratory's July 15, 1977, reques for confirmation that Part 572, *Anthropomorphic Test Dummy* (49 CFR 572), neither requires nor prohibits venting of the abdominal insert specified in drawing No. ATD 3250-2. The agency proposed the addition of leak test specifications to the drawing in August 1975 (40 CFR 33462, August 5, 1975) but they were not made final (42 CFR 7148, February 7, 1977).; Your interpretation that Part 572 neither requires nor prohibit venting of the abdominal insert is correct. The language you cite from the preamble to our February 1977 rulemaking is misleading in suggesting the requirement for venting. The agency more clearly described the requirement in its most recent amendment of Part 572 (42 FR 34299, July 5, 1977), stating that the Part does not 'specify an abdominal sealing specification.' Agency testing demonstrated conforming results both with and without venting (DOT HS-020875) and sees no reason to control this aspect of dummy design.; Sincerely, Joseph J. Levin, Jr., Chief Counsel |
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ID: aiam1782OpenMr. J.R. Farron,Bendix Corp.,P.O. Box 4001,South Bend, Indiana 46634; Mr. J.R. Farron Bendix Corp. P.O. Box 4001 South Bend Indiana 46634; Dear Mr. Farron:#Please forgive the delay in responding to your lette of November 8, 1974, concerning Federal Motor Vehicle Safety Standard No. 106-74, *Brake Hoses*.#In our letter of July 8, 1974, We explained that a neoprene connector, which you now designate as the Hydrovac Vacuum Connector, is included under the definition of 'brake hose,' set out in the standard, because it is flexible. Your letter of November 8, 1974, suggested that, due to the nature of the connector's installation, it is not subject to the usual hazards associated with the flexibility of brake hose. The connector is nevertheless a 'flexible conduit manufactured for use in a brake system to transmit or contain the fluid pressure or vacuum used to apply force to a vehicle's brakes,' and so cannot be excluded from the definition of 'brake hose' without further rulemaking activity. We are considering the possibility of an amendment of the definition to exclude this type of connector from the coverage of Standard No. 106-74. any such proposal would be published in the Federal Register.#Yours truly,James C. Schultz,Chief Counsel; |
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ID: aiam5434OpenMs. Sally O'Cordan Ashley, Hannula, & Halom 515 Belknap Street Superior, WI 54880; Ms. Sally O'Cordan Ashley Hannula & Halom 515 Belknap Street Superior WI 54880; "Dear Ms. O'Cordan: This responds to your question about whether an Federal motor vehicle safety standard (FMVSS) applies to glass used in a travel trailer. You stated that your law office was investigating an accident in which an individual was injured by glass of such a vehicle. Please be aware that no FMVSS applies to the glazing (the term the agency uses for glass) in trailers. The agency has issued one standard, FMVSS No. 205, Glazing Materials, (49 CFR 571.205), which applies to glazing in some motor vehicles. However, this standard does not apply to glazing in trailers, which our regulations define as 'a motor vehicle with or without motive power, designed for carrying persons or property and for being drawn by another motor vehicle' (49 CFR 571.3). You may wish to contact the State of Wisconsin about the regulation of glass in trailers. The State has the authority to regulate the operation and modification of vehicles by their owners. Wisconsin may have used this authority to issue regulations about glazing in travel trailers. I hope this information is helpful. Please feel free to contact Marvin Shaw of my staff at this address or by telephone at (202) 366-2992 if you have any further questions or need additional information. Sincerely, John Womack Acting Chief Counsel"; |
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ID: aiam0533OpenMr. William C. Bottger, Jr., Latham & Watkins, 615 South Flower Street, Los Angeles, CA 90017; Mr. William C. Bottger Jr. Latham & Watkins 615 South Flower Street Los Angeles CA 90017; Dear Mr. Bottger:This is in reply to your letter of November 16, 1971 in which you ask whether a manufacturer may add certain statements to the Certification label required pursuant to Part 567 of Title 49, Code of Federal Regulations. You state that the manufacturer in question is engaged in the manufacture and mounting of concrete mixer assemblies. Because, as you state, the weight of the concrete may vary according to the mix formula, and because the volume of mix loaded into a mixer can also vary, the manufacturer wishes to add to his Certification label a declaration of the vehicle's cargo load and an indication of the maximum volume of mix that could be safely hauled within the rated cargo load limit.; There is no prohibition to this additional information being added t the Certification label as long as (1) it appears after the required information, and (2) it is stated in such a way that it cannot be confused with the information, particularly the GVWR and GAWR, required to be placed on the label.; We are pleased to be of assistance. Sincerely, Richard B. Dyson, Assistant Chief Counsel |
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ID: aiam2109OpenMr. J. W. Lawrence, P.O. Box 91500, Cleveland, Oh 44101; Mr. J. W. Lawrence P.O. Box 91500 Cleveland Oh 44101; Dear Mr. Lawrence: This is in response to your July 19, 1976, letter requesting a interpretation of S567.4(g) of 49 CFR Part 567, *Certification*, with respect to the listing of pound and kilogram weight ratings.; You have cited my June 30, 1976, letter to Toyota Motor Sales, whic stated that weight ratings may be expressed in both pounds and kilograms, provided that each kilogram rating appears 'after' the corresponding pound rating. You have also cited 49 CFR Part 567.4(g), which specifies that 'Gross Axle Weight Rating' or 'GVWR' be 'followed by' the pound ratings for each axle, identified in order from front to rear.; If A and B are two items of information on a label, the NHTS interprets 'A is followed by 'B' to mean 'B appears to the right of A or below A or both.' We consider 'B appears after A' to have the identical meaning.; The pairing of pound and kilogram ratings that is permitted by th interpretation in the Toyota letter must appear hierarchically within the sequence of axle ratings specified in S567.4(g). For example, the following listing is permitted:; GAWR FRONT 2000 lbs/907 kgs REAR 2200 lbs/998 kgs, while the following listing is not permitted: GAWR FRONT 2000 lbs REAR 2200 lbs (907 kgs/998 kgs). Sincerely, Frank A. Berndt, Acting Chief Counsel |
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.