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: nht71-2.12OpenDATE: 03/09/71 FROM: AUTHOR UNAVAILABLE; R. H. Compton; NHTSA TO: Koito Manufacturing Co., Ltd. TITLE: FMVSS INTERPRETATION TEXT: This is in reply to your letter of February 25, 1971, concerning the photometric requirements for amber turn signal lamps. You have correctly interpreted the photometric requirements for amber turn signal lamps as specified in paragrap S4.1.1.7 of Federal Motor Vehicle Safety Standard No. 108, effective January 1, 1972. |
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ID: nht71-4.30OpenDATE: 10/22/71 FROM: AUTHOR UNAVAILABLE; Lawrence R. Schneider; NHTSA TO: Volkswagen of America, Inc. TITLE: FMVSS INTERPRETATION TEXT: This will serve to confirm your understanding that a retractor capable of meeting the requirements for a vehicle-sensitive emergency-locking retractor under Standard No. 209 conforms to the Standard even though it is provided with a back-up webbing-sensitive retractor that locks only at webbing accelerations greater than those specified in Standard No. 209. |
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ID: nht78-1.41OpenDATE: 02/21/78 FROM: AUTHOR UNAVAILABLE; Roger Tilton; NHTSA TO: Docket TITLE: FMVSS INTERPRETATION TEXT: SUBJECT: EX PARTE CONTACT On February 21, 1978, by phone at I met with/(spoke with) Mr. Dick Presno of Sheller Globe Corporation. Discussion: He asked whether a 34 inch seat cushion with a 39 inch seat back would be permitted to have a 30 inch restraining barrier. I told him that, in line with earlier interpretations, a 34 inch seat cushion would require a 34 inch restraining barrier. |
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ID: nht93-2.8OpenDATE: March 5, 1993 FROM: Jane L. Dawson -- Specifications Engineer, Thomas Built Buses, Inc. TO: Walter Myers -- Office of Chief Counsel, NHTSA TITLE: None ATTACHMT: Attached to letter dated 4-8-93 from John Womack to Jane L. Dawson (A41; Std. 217) TEXT: Per our phone conversation yesterday, I am requesting a written response to the following question: Is an exterior handle required on an emergency exit window in order to comply with the upcoming changes to FMVSS 217? |
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ID: nht74-5.55OpenDATE: 08/20/74 FROM: AUTHOR UNAVAILABLE; R. B. Dyson; NHTSA TO: Toyda Gosei Co., Ltd. TITLE: FMVSS INTERPRETATION TEXT: This responds to your August 8, 1974, question whether the effective date of Standard No. 106-74, Brake hoses, is September 1, 1974, for hose (and fittings) and March 1, 1975, for nose assemblies. Your interpretation is correct. The standard requires conforming hose (and fittings) as of September 1, 1974. It requires conforming assemblies (including the label band) only on March 1, 1975, and thereafter. |
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ID: nht69-2.47OpenDATE: 12/23/69 FROM: AUTHOR UNAVAILABLE; C. A. Baker; NHTSA TO: Department of California Highway Patrol TITLE: FMVSS INTERPRETATION TEXT: Thank you for your letter of December 8, 1969, concerning alternate flashing of side marker lamps with turn a signal lamps. Alternate flashing sidemarker lamps are permitted in paragraph S3.5 of Motor Vehicle Safety Standard No. 108 for signaling purposed; however, they must not impair the effectiveness of the turn signal lamps as required in paragraph S3.1.2. |
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ID: nht72-1.30OpenDATE: 06/08/72 FROM: AUTHOR UNAVAILABLE; R. B. Dyson; NHTSA TO: Michlin Tire Corporation - Technical Division TITLE: FMVSS INTERPRETATION TEXT: In reply to your letter of May 16, 1972, your interpretation is correct that paragraph S4.3.2 of Motor Vehicle Safety Standard No. 109 requires either the manufacturer's name and his assigned code number, or the brand name and the manufacturer's assigned number to be labeled onto the tire. The code number must appear in either case. |
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ID: nht71-3.44OpenDATE: 07/21/71 FROM: AUTHOR UNAVAILABLE; L. R. Schneider; NHTSA TO: Peterson Manufacturing Company TITLE: FMVSS INTERPRETATION TEXT: In reply to your letter of July 9, you are correct in assuming "it will still be permissible to illuminate motorcycle license plates from the bottom even after January 1, 1973." The installation requirements of Standard No. 108, as set out in SAE Standard 587d, License Plate Lamps, March 1969, do not apply to motorcycles and motor driven cycles. |
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ID: nht73-2.20OpenDATE: 12/22/73 FROM: AUTHOR UNAVAILABLE; Robert L. Carter; NHTSA TO: American Safety Equipment Corporation TITLE: FMVSS INTERPRETATION TEXT: This is in reference to our letter of August 20, 1973 (copy enclosed), requesting additional technical information on your harness release mechanism (the subject of your August 3, 1973, Petition for Rule Making). Please inform us within ten days whether or not you intend to furnish us the information we requested in our letter, so that we may make a final decision on your Petition for Rule Making action. |
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ID: nht71-1.9OpenDATE: 03/09/71 FROM: AUTHOR UNAVAILABLE; R. H. Compton; NHTSA TO: Truck Body and Equipment Association, Inc. TITLE: FMVSS INTERPRETATION TEXT: This is in reply to your letter of February 23, 1971, to Mr. Julian B. Leysath of this office requesting an interpretation on the mounting location of rear clearance lamps on slant-sided beverage truck bodies. Rear clearance lamps mounted on the outermost top corners of the body, as indicated on the TBEA diagram, adequately meet the location requirements of Federal Motor Vehicle Safety Standard No. 108. |
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.