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: nht95-2.85OpenTYPE: INTERPRETATION-NHTSA DATE: May 18, 1995 FROM: Jane L. Dawson -- Specifications Engineer, Thomas Built Buses, Inc. TO: Walter Myers -- Chief Counsel's Office, NHTSA TITLE: NONE ATTACHMT: ATTACHED TO 8/4/95 LETTER FROM JOHN WOMACK TO JANE L. DAWSON (A43; STD. 217; REDBOOK 2) TEXT: Dear Mr. Myers, Please provide an interpretation on the following: In the final rule for FMVSS 217, Bus Emergency Exits and Window Retention and Release published in the Federal Register May 9, 1995, what are the location requirements (fore and aft) for emergency windows which may now be used as the first additional eme rgency exit? Your quick response is appreciated. |
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ID: nht67-1.15OpenDATE: 02/27/67 FROM: AUTHOR UNAVAILABLE; William Haddon, Jr. M.D.; NHTSA TO: Edward K. Kennedy, Esq. TITLE: FMVSS INTERPRETATION TEXT: This is in reply to your letter of February 10, 1967. Motor Vehicle Safety Standard No. 105 applies only to new passenger cars manufactured January 1, 1968, or later. Although the National Traffic Safety Agency intends to issue additional standards in the future that apply to items of motor vehicle equipment, most of the initial Motor Vehicle Safety Standards issued January 31, 1967, apply to vehicles only, as the application paragraph of each standard specifies. Please do not hesitate to call upon us if we can be of further service to you. |
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ID: nht69-1.35OpenDATE: 04/01/69 FROM: AUTHOR UNAVAILABLE; R. M. O'Mahoney; NHTSA TO: European Tire and Rim Technical Organization TITLE: FMVSS INTERPRETATION TEXT: This is in reply to your letter of January 21, 1969, requesting the "actual state of affairs" concerning States requiring a V-1 marking on tires. You are correct in your understanding that the Federal tire standard (No. 109 preempts or supersedes any State regulation applicable to the same aspect of performance. The Federal tire standard does not require tires to be marked with the "V-1" symbol. However, it does not prohibit such marking. Our understanding is that American tire manufacturers have continued marking their product with "V-1" symbol although not required to do so by the Federal standard. |
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ID: nht69-2.7OpenDATE: 01/13/69 FROM: AUTHOR UNAVAILABLE; Clue D. Ferguson; NHTSA TO: Baycraft TITLE: FMVSS INTERPRETATION TEXT: Your letter of December 2, 1968, to Mr. William L. Hall, concerning safety glazing in canopies, has been referred to me for reply. FHWA Ruling 68-1 clarified the requirement that slide-in campers must comply with Standard 205 since they are items of motor vehicle equipment for use in motor vehicles. A copy of FHWA Ruling 68-1 is enclosed. The same rationale applies to your canopies. Forward facing windows must be laminated safety glass meeting the requirements of Test No. 26 of ASA Standard Z26.1-1966, July 15, 1966. Other windows may be AS1, 2, 3, 4, 5, 6, 7, 10, 11, 2-26, or 3-26. |
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ID: nht68-2.16OpenDATE: 06/26/68 FROM: AUTHOR UNAVAILABLE; George C. Nield; NHTSA TO: Volvo, Icorporated TITLE: FMVSS INTERPRETATION TEXT: Thank you for your letter of May 15, 1968, concerning electrically heated glass which you anticipate using for rear windows in your motor vehicles. The present glazing requirement for motor vehicles are covered in Motor Vehicle Safety Standard No. 205, "Glazing Materials." Section S3, Requirements, stipulates that the glazing materials used must conform to U.S.A. Standard Z 26.1-1966, "American Standard Safety Code for Safety Glazing Materials for Glazing Motor Vehicles Operating on Land Highways," July 15, 1966. If the electrically heated glass you mentioned meets the requirements of Standard No. 205, we would have no objection to is use. |
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ID: nht68-4.6OpenDATE: 08/27/68 FROM: AUTHOR UNAVAILABLE; H. M. Jacklin, Jr.; NHTSA TO: Volkswagen of America, Inc. TITLE: FMVSS INTERPRETATION TEXT: This will acknowledge your letter of July 31, 1968, to Mr. George C. Neild, Motor Vehicle Safety Performance Service, requesting the addition of a 5-K rim for use with a 5.60 x 15 tire to Table II of Federal Motor Vehicle Safety Standard No. 110. On the basic of the data submitted showing satisfactory completion of the test requirements specified in the Federal Motor Vehicle Safety Standards No. 109 and No. 110, your request for the approved equivalent rim is granted. The 5-K rim will be listed in Table II of Standard No, 110 and published in the Federal Register. |
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ID: nht71-1.47OpenDATE: 01/08/71 FROM: R. H. COMPTON -- NHTSA; SIGNATURE BY CHARLES A. BAKER TO: A. Hammerstein TITLE: FMVSS INTERPRETATION TEXT: This is in reply to your letter of December 23, 1970, to the U. S. Department of Tranportation concerning the time when stop lamps will be required to meet Class A photometrics. The conflict between the requirements of paragraphs S4.1.1.6 and S4.1.1.7 has already been called to our attention, and will be clarified in an amendment to Standard No. 108 scheduled to be published in the Federal Register in the near future. It was not intended for the stop lamps to meet the Class A photometric values, nor are they required to, until January 1, 1973. |
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ID: nht72-2.32OpenDATE: 01/13/72 FROM: AUTHOR UNAVAILABLE; C. A. Baker for E. T. Driver; NHTSA TO: Joseph Lucas North America, Inc. TITLE: FMVSS INTERPRETATION TEXT: This is in reply to your letter of December 23, 1971, to Mr. J. E. Leyseth of this Office in which you asked if each reflex area in a two-section reflector separated by a side marker lamp needs to meet the photometric requirements of a Class A reflector. Each reflex area need not meet the photometric requirements for a Class A reflex reflector provided that when the areas are combined they meet the photometric requirements, and provided further, that the marker lamp lens is included in the maximum exposed area of 12 sq. in. contained within a 7 in. diameter circle per SAE J594d. |
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ID: nht72-2.34OpenDATE: 04/13/72 FROM: AUTHOR UNAVAILABLE; R. B. Dyson; NHTSA TO: Amerace - Esna Corporation TITLE: FMVSS INTERPRETATION TEXT: In your letter of February 4 to Mr. Schneider you discussed differences between SAS Standard J594d, March 1957, Reflex Reflectors, and its successor J594e, March 1970. You asked "whether relief can be granted in the unnecessary specular restriction appearing in Federal Motor Vehicle Safety Standard No. 108 because of its inclusion of J594d rather than J594e." We have reviewed your letter and the administrator has determined that the issue you raised merits (Illegible Word) of rulemaking. I enclose a copy of a notice proposing an amendment to Standard No. 108 to substitute SAE J594e as the referenced requirement for reflex reflectors. |
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ID: nht72-2.46OpenDATE: 07/18/72 FROM: AUTHOR UNAVAILABLE; Richard B. Dyson; NHTSA TO: Gold Eagle Products Company TITLE: FMVSS INTERPRETATION TEXT: This is in response to your letter of June 23, 1972 asking if there is any objection to placing the information required by paragraph S5.2.2.2(d) of Standard No.116 on the top of brake fluid containers. Stamping this information on the top of the container would meet the requirements of S5.2.2.2(d) that it be located on the bottom or on the side, underneath the distributor's name and mailing address. However, we are reviewing the matter and if we decide to modify the requirements, the appropriate notices will be published in the Federal Register. |
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.