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: nht68-1.3OpenDATE: 08/22/68 FROM: AUTHOR UNAVAILABLE; R. M. O'Mahoney; NHTSA TO: E.T.R.T.O. TITLE: FMVSS INTERPRETATION TEXT: This in response to your letters of May 24, requesting (1) a footnote to Table 1-A to provide that equivalent millimeter designations may be marked on tire sizes in addition to the dimension sizes in inches; and (2) a footnote to Table 1-C to provide that the tire sizes provided in this table can be marked on the tire by giving the millimeter equivalent either before or after the size designation in inches. We do not consider that Table 1-A of the standard, as presently written, prohibits equivalent marking in millimeters as long as the conversion from inches to millimeters is exact and the tire meets the size and load carrying requirements shown in Table 1-A. Similarly, we do not consider that the standard as presently written prohibits the marking of the tire with equivalent millimeter sizes before or after the marking which gives the size of the tire in inches. In view of the above, a footnote is not considered necessary. |
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ID: nht69-2.36OpenDATE: 12/23/69 FROM: AUTHOR UNAVAILABLE; C. A. Baker; NHTSA TO: Blue Bird Body Company TITLE: FMVSS INTERPRETATION TEXT: Thank you for your letter of December 9, 1969, providing additional information on the school bus lighting system as described in your previous letter of November 14, 1969. Paragraph S3.1.2 of Federal Motor Vehicle Safety Standard No. 108 specifies that, The additional lamp, reflective device, and associated equipment shall be installed if it impairs the effectiveness of the required equipment." The system of front stop lamps as described in your letters, i.e., two non-flashing amber lamps of the same size as and located in line with the two red school bus signal lamps, and actuated by the foot brake only, would not appear to impair the effectiveness of the lighting equipment required by Standard No. 108. It should be noted, however, that, while incorporation of this system in school buses would not be precluded by Standard No. 108, the various States may interpose restrictions as to such system. I would suggest, therefore, that you review the applicable State regulations before initiating installation of the system. |
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ID: nht68-1.44OpenDATE: 06/03/68 FROM: AUTHOR UNAVAILABLE; Joseph R. O'Gorman; NHTSA TO: Bert's Truck Equipment Incorporated TITLE: FMVSS INTERPRETATION TEXT: Thank you for your letter of April 18, 1968, in which you provided certification information, and presented extra axle modification problems. Enclosed is a copy of the Federal Motor Vehicle Safety Standards with chassis-cab information from the Federal Register. Your certification of compliance concerns compliance of the vehicle at the time of your installation or modification. It does not extend to subsequent additions or modifications by others. With respect to an old truck body mounted on a chassis-cab which is manufactured on or after January 1, 1968, you are required to bring the lighting into compliance. (See Federal Standard 108 applicable for January 1, 1965. With regard to lighting requirements for trucks, the corner lights, or side marker and clearance lamp requirements are also provided in the foregoing, enclosed standard. Your letter is being referred to the engineers responsible for standards preparation, and the information is appreciated. |
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ID: nht68-2.46OpenDATE: 07/22/68 FROM: AUTHOR UNAVAILABLE; David A. Fay; NHTSA TO: Dompster Brothers, Incorporated TITLE: FMVSS INTERPRETATION TEXT: Thank you for your letter of June 28, 1968, to Mr. James R. O'Gorman, Acting Director, Office of Performance Analysis, requesting comments on the lamps, reflective devices and associated equipment on your container handling equipment. The lamps and reflectors shown on your drawing A-B4333 through A-B4339 enclosed in your Engineering Bulletin No. 1 dated May, 1965, appear to be in conformance with the requirements of Standard No. 1 (Illegible Word) Since no dimensions are included on your drawings, we can only assumes that the locations are as specified in the standard. With respect to the requirements of Standard No. 108, I must point out that this Bureau does not issue approval on items of lighting equipment or on vehicle designs incorporating this equipment. Therefore, the above comments are for your information only and is no way relieve the vehicle manufacturer from his responsibility for certifying that the assembled vehicle meets the requirements of Standard No. 108. |
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ID: nht68-2.9OpenDATE: 06/24/68 FROM: AUTHOR UNAVAILABLE; Joseph R. O'Gorman; NHTSA TO: Selma Trailer and Manufacturing Company TITLE: FMVSS INTERPRETATION TEXT: Thank you for your letter of May 2, 1968, which included additional information for certification under Public Law 89-563 and your coments. You will note that Federal Motor Vehicle Safety Standard No. 108 does not restrict the height of the identification lamps from the roadway. You may find it suitable to mount these lights at a lower level than indicated in your illustrations. With respect to the requirements of Standard No. 103, I must point out that this Bureau does not issue approvals on items of lighting equipment or on vehicle designs incorporating this equipment. Therefore, the above comments are for your information only and in no way relieve the vehicle manufacture from his responsibility for certifying that the assembled vehicle meets the requirements of the standard. I am enclosing a copy of the National Traffic and Motor Vehicle Safety Act of 1966 which defines the vehicles to which it applies. |
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ID: nht68-3.42OpenDATE: 07/22/68 FROM: AUTHOR UNAVAILABLE; William Haddon, Jr., M.D. NHTSA TO: General Motors Technical Center TITLE: FMVSS INTERPRETATION TEXT: This is in reference to your letter of June 14, 1968. Enclosed is the Grant of Approval for equivalent seat assembly attachment hardware as requested in your letter. U.S. DEPARTMENT OF TRANSPORTATION FEDERAL HIGHWAY ADMINISTRATION NATIONAL HIGHWAY SAFETY BUREAU General Motors Corporation General Motors Technical Center Warren, Michigan 48090 GRANT OF APPROVAL In accordance with Paragraph S3. of Motor Vehicle Safety Standard No. 209, as amended, effective March 1, 1967, an interrupted thread bolt is an approved equivalent to the bolts specified in paragraph (f) of section 9.3 of Department of Commerce, National Bureau of Standards, Standards for Seat Belts for Use in Motor Vehicles (15 CFR 9) (31 F.R. 11528), provided it meets all other requirements of 15 CFR 9. Sincerely, William Haddon, Jr., M.D. Director Issued in Washington, D. C. on July 22, 1968 |
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ID: nht70-2.44OpenDATE: 12/29/70 FROM: AUTHOR UNAVAILABLE; Lawrence R. Schneider; NHTSA TO: Mitchell & Sons, Inc. TITLE: FMVSS INTERPRETATION TEXT: This is in response to your letter of December 16, 1970, requesting a clarification of our October 8, 1970 letter on the subject of the compliance of your campers with Standard No. 206. The second paragraph in our letter was intended to apply to both your 14' 6" and 12' 6" campers and should leave read as follows: "You are correct in stating that the door in camper bodies built according to either of the floor plans enclosed with your letter would not be required to comply with Standard No. 206 if, as it appears, no portion of a manikin positioned at any seating reference point would project into the door opening area." Of course, it is your responsibility under the National Traffic and Motor Vehicle Safety Act to determine whether both types of your campers actually meet the provisions of that paragraph. Please write if we can be of further assistance. |
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ID: nht71-1.26OpenDATE: 05/16/71 FROM: AUTHOR UNAVAILABLE; Rodolfo A. Diaz; NHTSA TO: Mitsubishi Motors Corporation TITLE: FMVSS INTERPRETATION TEXT: Thank you for your letter of February 17, 1971, to Mr. Douglas W. Torns, regarding positioning of the anthropornorphic test devices for use in the crashes described in Federal Motor Vehicle Safety Standard No. 208. I am enclosing a copy of the newly revised version of the standard as well as an accompanying press release. In regard to your specific inquiry, Standard No. 208 does not contain specifications for the alignment of the dummy's head once positioned in the vehicle. Paragraph S8.1.11(a) specifies that the dummy head is aligned prior to positioning in the vehicle. Paragraphs S8.1.11(b) through (c) specify the procedure for positioning the dummy in the vehicle seat. If the procedures in S8.1.11 are followed as specified, the dummy's neck and head may actually be inclined because of contact with the roof or other vehicle components. Thank you for your interest in our motor vehicle safety programs. |
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ID: nht71-1.6OpenDATE: 08/09/71 FROM: AUTHOR UNAVAILABLE; Robert L. Carter; NHTSA TO: Holen Company TITLE: FMVSS INTERPRETATION TEXT: This is in reply to your letters of June 30 and August 2 on the subject 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 handing 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. |
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ID: nht71-2.33OpenDATE: 04/29/71 FROM: AUTHOR UNAVAILABLE; Clue D. Ferguson; NHTSA TO: Ashimori Industry Company, Ltd. TITLE: FMVSS INTERPRETATION TEXT: Thank you for your letter of April 1, 1971, regarding self-fastening seat belt systems. Any system which requires no action by vehicle occupants can be used to meet the appropriate options of Federal Motor Vehicle Safety Standard No. 208 - Occupant Crash Protection. "The action," in this case, means that no action is permitted by vehicle occupants other than would be required if the protective system were not present in the vehicle. We have received a number of petitions for reconsideration or clarification of Notice 9, particularly in reference to the role of a passive (no action) safety belt system as it relates to the requirements for Type 1 or Type 2 seat belt installations prior to August 15, 1975. We are now in the process of resolving the petitions received, and our final decisions in response to the petitions will be issued in the Federal Register as soon as possible. Your interest in our motor vehicle safety programs is most appreciated. |
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.