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: nht90-4.3OpenTYPE: Interpretation-NHTSA DATE: September 13, 1990 FROM: Danny Pugh -- Engineering Manager, Utilimaster TO: Chief Counsel, NHTSA TITLE: None ATTACHMT: Attached to letter dated 12-13-90 to Danny Pugh from Paul Jackson Rice (A36; Std. 208; Part 571.3) TEXT: We are updating our files on FMVSS 208 in relationship to van conversions under 10,000 pounds GVW. Is a van conversion classified as a passenger car, truck or a multi passenger vehicle? On what date did van conversions require seatbelts, what type, and at what location? Did van conversions ever require Type II seatbelts? At what location in the van? Your help with these questions will be appreciated. (Attached is a brochure from Aviator Conversions listing van conversion specifications and options. (Text and graphics omitted.)) |
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ID: nht90-4.48OpenTYPE: Interpretation-NHTSA DATE: October 19, 1990 FROM: Tom Wiatrak -- Century Products Company TO: Deidre Fujita -- Chief Counsel, NHTSA TITLE: None ATTACHMT: Attached to letter dated 1-3-91 from Paul Jackson Rice to Tom Wiatrak (A37; Std. 213) TEXT: We are enclosing pictures of a suggested location for the warning and instruction labels for a new carseat pad. This surround pad covers the sides of the casting thus hiding the labels installed in the normal position. We would like to add tyvek warnin g and instruction labels sewn to the pad as shown in addition to the labels that appear on the casting. Please advise at your earliest convenience if this proposal meets the requirements of FMVSS 213. Attachment Photos of label location on carseat pad. (Photos omitted.) |
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ID: nht89-1.97OpenTYPE: INTERPRETATION-NHTSA DATE: 06/08/89 FROM: ROBERT J. KNAUFF -- APPLIED RESEARCH AND DESIGN TO: KATHLEEN DEMETER -- ASSISTANT CHIEF COUNSEL FOR GENERAL LAW U.S. DEPARTMENT OF TRANSPORTATION TITLE: NONE ATTACHMT: ATTACHED TO LETTER DATED 07/24/89 FROM STEPHEN P. WOOD -- NHTSA TO ROBERT KNAUFF; REDBOOK A33; FMVSS 108; LETTER DATED 08/16/88 FROM RICHARD H. SCHULTZ -- AMERICAN PULSE LIGHTS INC TO ROBERT KNAUFF; LETTER DATED 12/07/87 FROM RICHARD H. SCHULTZ -- AMERICAN PULSE LIGHTS TO ROBERT J. KNAUFF TEXT: Dear Ms. DeMeter: Confirming our phone conversation relating to your letter dated May 26, 1989, this is to confirm that you have my permission to use the information marked "confidential" in determining if my collision avoidance system will conform to the existing laws. If you have any other questions, please feel free to contact me. Professionally, |
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ID: 1985-04.51Open TYPE: INTERPRETATION-NHTSA DATE: 12/31/85 FROM: AUTHOR UNAVAILABLE; Erika Z. Jones; NHTSA TO: Mr. Warren H. Cox TITLE: FMVSS INTERPRETATION TEXT:
December 31, 1985 Mr. Warren H. Cox Haynesville Correction Unit #17 Haynesville, VA 22472 Dear Mr. Cox: This is to follow-up on the letter of October 11, 1985, sent to you concerning the effect of our regulations on modifications made to used vehicles. Unfortunately, there was a typographical error in the third sentence of the third paragraph, The sentence should have read "However, in making modifications to a used vehicle, commercial businesses do not have to comply with the safety standards that would apply if the modifications are made before the vehicle is first sold." We regret the error. Sincerely, Original Signed By Erika Z. Jones Chief Counsel
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ID: 86-1.13OpenTYPE: INTERPRETATION-NHTSA DATE: 01/30/86 FROM: AUTHOR UNAVAILABLE; Erika Z. Jones; NHTSA TO: Commander, Naval Safety Center, Naval Air Station, Norfold, VA TITLE: FMVSS INTERPRETATION TEXT:
Commander Naval Safety Center Naval Air Station Norfolk, VA 23511-5796 Ref: 5100 Ser 42/5064 Thank you for your letter of December 5, 1985, following up on a number of phone conversations between your staff and mine, concerning the effective dates of the Federal standard requiring the installation of safety belts in motor vehicles. As requested by your staff, we have prepared the enclosed information sheet to be used as a guide by your security personnel in enforcing the safety belt use requirements on naval installations. If you have any further questions, please let me know. Sincerely, Original Signed By Erika Z. Jones Chief Counsel Enclosure |
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ID: 77-1.20OpenTYPE: INTERPRETATION-NHTSA DATE: 02/11/77 FROM: AUTHOR UNAVAILABLE; F. Berndt; NHTSA TO: Hon. M. C. Hatfield - U.S. Senate TITLE: FMVSS INTERPRETATION TEXT: With regard to my letter to you of July 1, 1976, concerning the application of Standard No. 120, Tire Selection and Rims for Motor Vehicles Other than Passenger Cars, to the paver manufactured by Layton Manufacturing Company of Salem, Oregon, I would like to advise you of a clarification of the requirements of the standard that may be relevant to Layton's product. Essentially, it has been clarified that the requirement of S5.1.1 of the standard accommodates a manufacturer's decision to equip its motor vehicle with tires other than "tires for highway service." This means that Layton can choose to use tires that do not conform to the requirements set forth in S5.1.1 of the standard. I have enclosed a copy of the notice that contains a detailed discussion of this clarification. |
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ID: 77-4.15OpenTYPE: INTERPRETATION-NHTSA DATE: 10/07/77 FROM: AUTHOR UNAVAILABLE; J. J. Levin, Jr.; NHTSA TO: Motor Coach Industries, Inc. TITLE: FMVSS INTERPRETATION TEXT: This will acknowledge receipt of the petition by Motor Coach Industries, dated July 22, 1977, for a determination that an apparent noncompliance with Motor Vehicle Safety Standard No. 121 is inconsequential as it relates to motor vehicle safety. We are preparing a notice for publication in the Federal Register requesting public comment on your petition and you will be notified in due course as to its disposition. The notice will not include reference to the fact that the "continuous warning" signal required by S5.1.5 of Standard No. 121 is an automatic flashing light on MCI vehicles. It is the opinion of this office that either an automatic flashing light or a continuous light will provide a "continuous warning" within the intent of the Standard. |
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ID: nht81-2.43OpenDATE: 07/07/81 FROM: AUTHOR UNAVAILABLE; F. Berndt; NHTSA TO: Carabela USA, Inc. TITLE: FMVSS INTERPRETATION TEXT: This is in reply to your letter of June 8, 1981 requesting "the candlepower rating on a moped headlamp." I enclose a copy of SAE Standard J584 Motorcycle and Motor Driven Cycle Headlamps April 1964, which contains the information that you request. Most mopeds develop 5 horsepower or less and thus qualify as a "motor driven cycle." If you have any further questions, we shall be pleased to answer them. ENC. Carabela USA, Inc. 6-8-81 Office of Chief Council NHTSA Dear Mr. Schwartz: Please quote me the candlepower rating on a moped headlamp, if any. Thank you. Barry N. Aebischer Mktg. Coordinator |
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ID: nht74-1.3OpenDATE: 10/07/74 FROM: AUTHOR UNAVAILABLE; R. B. Dyson; NHTSA TO: Borg-Warner Corporation TITLE: FMVSS INTERPRETATION TEXT: OCT 7 1974 N40-30(ZTV) Mr. Mike A. Read Design Engineer, Spring Division Borg-Warner Corporation 700 South 25th Avenue Bellwood, Illinois 60104 Dear Mr. Read: This is in reply to your letter of September 13, 1974, pointing out discrepancies between our two standards covering motor vehicle hydraulic brake systems, Nos. 105-75 and 122. We intend to amend Standard No. 122 in the near future to be consistent with Standard No. 105-75. This will clarify that the same interpretation will be given master cylinder reservoir and capacity requirements. Thank you for pointing this out to us. Yours truly, Richard B. Dyson Acting Chief Counsel |
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ID: nht78-2.47OpenDATE: 01/10/78 FROM: AUTHOR UNAVAILABLE; J. J. Levin, Jr.; NHTSA TO: Briskin Manufacturing Company TITLE: FMVSS INTERPRETATION TEXT: I would like to advise Briskin Manufacturing Company as a producer of air reservoirs for use on vehicles that comply with Standard No. 121, Air Brake Systems, that the National Highway Traffic Safety Administration (NHTSA) has decided to withdraw its December 14, 1977, interpretation of the requirement that reservoirs "withstand" internal hydrostatic pressure (copy of interpretation enclosed). While the NHTSA simply intended to clarify its existing interpretation of the requirements, information brought to the agency's attention indicates that the revised interpretation would have the unintended effect of increasing the stringency of the requirements. Any such upgrading of the integrity requirements for air reservoirs would be preceded by notice and opportunity for public comment. The agency expects to publish notice that its interpretation is withdrawn in the Federal Register in the near future. |
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.