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: nht72-2.29OpenDATE: 06/12/72 FROM: AUTHOR UNAVAILABLE; C. A. Baker for E. T. Driver; NHTSA TO: Harker Enerprises, Inc. TITLE: FMVSS INTERPRETATION TEXT: This responds to your letter of May 22, 1972, to the Director, National Highway Traffic Safety Administration, concerning your patented Anti-Clare lenses for automotive headlights. Federal Motor Vehicle Safety Standard No. 108 does prohibit the installation of devices in front of the headlamp lens, and also allows only white light from the headlights (Illegible Word) you have correctly concluded. There is no expectation of any future significant change in this area of Standard No. 108 requirements. These requirements of Standard No. 108 are applicable to original equipment furnished on new vehicles; therefore, the allowance of sale of your Anti-Glare lenses in the aftermarket is under the jurisdiction of the Individual States. |
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ID: nht71-4.28OpenDATE: 10/22/71 FROM: AUTHOR UNAVAILABLE; L. R. Schneider; NHTSA TO: Nissan Motor Company, Ltd. TITLE: FMVSS INTERPRETATION TEXT: In your letter of October 14 you ask whether reflex reflectors on the tail gate of a pick-up truck, as shown in Figure 1 of the drawings you enclosed, meet the requirements of Federal Motor Vehicle Safety Standard No. 108, Lamps, Reflective Devices, and Associated Equipment. Standard No. 108 requires, in part, that reflex reflectors be mounted "on the rear" of a vehicle. Compliance with the requirements of Standard No. 108 is judged with the vehicle in its normal road operating condition. In our view, a pick-up truck is normally operated with the tail gate in a closed position, and the reflex reflectors mounted as shown in Figure 1 appear to meet the rear reflector location requirements of Standard No. 108. |
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ID: nht71-5.37OpenDATE: 09/30/71 FROM: AUTHOR UNAVAILABLE; Robert L. Carter; NHTSA TO: Mercedes Benz of North America TITLE: FMVSS INTERPRETATION TEXT: This is in reply to your letter of August 20, 1971, in which you asked whether the shoulder belt anchorages installed by Mercedes in its heavy trucks (over 10,000 CVWR) must meet the strength requirements of Standard No. 210, even though the standard does not require shoulder belt anchorages in vehicles over 10,000 pounds GVWR. It is our opinion that because these anchorages are not required to be installed, they are not required to meet the strength requirements of Standard No. 210. You may therefore continue to use plastic covers on the anchorages and need not redder them unusable. Please advise us if you have further questions. |
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ID: nht71-5.61OpenDATE: 09/15/71 FROM: AUTHOR UNAVAILABLE; C. A. Baker for E. T. Driver; NHTSA TO: E. R. Buske Mfg. Co., Inc. TITLE: FMVSS INTERPRETATION TEXT: Your letter of September 3, 1971, to the Bureau of Motor Carrier Safety concerning the mounting of lamps on a body backplate has been referred to this Office for consideration and reply. Federal Motor Vehicle Safety Standard No. 108 requires that lamps meet the applicable SAE Standards (including the photometric specifications) when tested as mounted on the vehicle. (See SAE J575c, Paragraph J.) The maximum angle from a line perpendicular to the longitudinal centerline of the vehicle that a lamp can be mounted and meet the applicable requirements depends upon the design and configuration of the lamp. We therefore recommend that you contact the manufacturer of your lamps for this maximum angle information. |
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ID: nht72-4.18OpenDATE: 10/24/72 FROM: AUTHOR UNAVAILABLE; Robert L. Carter; NHTSA TO: Rose Manufacturing Company TITLE: FMVSS INTERPRETATION TEXT: Thank you for your letter of September 19, 1972, to Mr. Francis Armstrong, concerning seat belt model designations. The intent of paragraph S4.1(k) of Federal Motor Vehicle Safety Standard No. 209 is to require different model numbers for seat belt assemblies that differ in basic design concept. We would not consider belt assemblies that differ only in the size or number of cross threads in the webbing to be separate models. On the other hand, a belt assembly that incorporates a push button type buckle would be considered a separate model from an assembly that incorporates a lift cover type buckle. If we can be of further assistance, please do not hesitate to contact us. |
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ID: nht72-4.9OpenDATE: 01/26/72 FROM: AUTHOR UNAVAILABLE; Richard B. Dyson; NHTSA TO: Volkswagen of America, Inc. TITLE: FMVSS INTERPRETATION TEXT: As noted in your letter of January 18, 1972, the section of Standard 208 dealing with passive belts states, in S4.5.2.3, that passive belts furnished under S4.5.2 do not have to conform to S7.4 of the standard. As you correctly note, the standard as it presently exists does not contain a section S7.4. The section to which S4.5.3.3 refers is the S7.4 proposed in the notice regarding seat belt interlocks. Until such time as the interlock proposal is adopted, the reference to S7.4 should be disregarded. Since the reference will serve a purpose when the interlock provisions are adopted, we do not intend to delete it at this time. |
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ID: nht91-2.8OpenDATE: March 4, 1991 FROM: John E. Calow -- Sr. Safety Engineer, Oshkosh Chassis Division TO: Chief Council, NHTSA COPYEE: Gary Schmiedel TITLE: None ATTACHMT: Attached to letter dated 5-8-91 from Paul Jackson Rice to John E. Calow (A37; Std. 105; Std. 108) TEXT: Oshkosh Chassis Division (OCD) is submitting this letter for a written interpretation of FMVSS 105 with regard to Parking Brake actuation times. It is OCD's understanding that there is no requirement for Parking Brake actuation times of hydraulic brake systems. This is based upon information attained from reference material 49 CFR 571.105. OCD would appreciate a written affirmation or denial of our understanding of Parking Brake actuation times. Thank you for your time. |
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ID: nht92-7.48OpenDATE: April 6, 1992 FROM: Gonshiro Miyoshi -- Manager, Design Administration Dept., Technical Division Ichikoh Industries, Ltd. TO: Paul Jackson Rice -- Chief Counsel, NHTSA TITLE: Our Reference LO4-11 ATTACHMT: Attached to letter dated 5/8/92 from Paul J. Rice to Gonshiro Miyoshi (A39; Std. 108) TEXT: This letter is in regards to the interpretation of headlamp arrangement in FMVSS No. 108. We would like to know your opinion regarding the below mentioned arrangement of headlamp system consisting of two lamps, each containing two light sources. Is it permissible to have the bulb center of the lower beam lower than that of the upper beam (maximum height difference is 10mm) if they are arranged horizontally? Kindly let us know your opinion concerning the above matter. |
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ID: nht87-3.25OpenTYPE: INTERPRETATION-NHTSA DATE: 11/09/87 FROM: RICHARD J. STROHM TO: EDWARD JETTNER -- NATIONAL HWY. TRAFFIC SAFETY ADMIN. TITLE: NONE ATTACHMT: ATTACHED TO LETTER DATED 07/31/89 FROM STEPHEN P. WOOD -- NHTSA TO RICHARD J. STROHM. REDBOOK A33; FMVSS 207; VSA 108 [A] [2] [4] LETTER DATED 10/07/87 FROM RICHARD J. STROHM TO CHEVROLET DIVISION; 1987 CHEVROLET CAPRICE, 1G1BL51H0HX163146, 900 0 MILES TEXT: Gentlemen: A General Motor's Customer Service representative referred me to your Administration when I requested that they authorize the moving of the front seat in the 1987 Chevrolet Caprice that I drive. The attached letter to Chevrolet explains the problem. Th e Customer Service Representative tells me he cannot, by law, move the seat. Please tell me how Chevrolet can obtain authorization to move the seat in the 1987 Caprice. Very truly yours, Attachment |
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ID: nht76-2.36OpenDATE: 11/22/76 FROM: AUTHOR UNAVAILABLE; E. T. Driver; NHTSA TO: TYM Industries Co., Ltd. TITLE: FMVSS INTERPRETATION TEXT: This is in reply to your letter of September 27, 1976, to the National Highway Traffic Safety Administration, concerning lighting requirements for mopeds. The headlamp must be designed to conform to SAE Standard J584, "Motorcycle and Motor Driven Cycle Headlamps," April 1964. This Standard does not require a sealed beam headlamp, nor is a minimum wattage specified. Obtaining an AAMVA certificate is probably the best way of insuring that a State raises no obstacles to registry of your vehicle. There is no minimum wattage for the taillamp or stop lamp. These two lamps may be combined. There is no Federal requirement for SAE identification; however, most lamps are so identified, because of the requirements in the state of Virginia. |
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.