
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: nht70-2.3OpenDATE: 04/20/70 FROM: AUTHOR UNAVAILABLE; Douglas W. Toms; NHTSA TO: Ford Motor Company TITLE: FMVSR INTERPRETATION TEXT: This is in reply to your letter of March 19, 1970, with which you submitted for our examination a sample format for consumer information produced by a computer. The sample that you submitted does deviate from the requirements of the consumer information regulations in that the required warnings and explanations are placed on a sheet that is separate from the numerical data. The regulations generally require that the information be presented in the form illustrated by the published figures, with the explanatory matter in proximity to the numerical data. I believe that computer printing is flexible enough to allow you to accomplish this. |
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ID: nht70-2.30OpenDATE: 10/19/70 FROM: AUTHOR UNAVAILABLE; Lawrence R. Schneider; NHTSA TO: Department of California Highway Patrol TITLE: FMVSS INTERPRETATION TEXT: By letter of October 1, 1970, you asked for the opinion of this office as to whether the State of California, in specifying approval procedures for seat belts to be sold within the State, must require seat belt manufacturers to produce data showing that they have performed the exact tests specified in Federal Motor Vehicle Safety Standard No. 209. The Federal motor vehicle safety standards are not instructions for, or descriptions of, manufacturer tests, nor do they specify types and numbers of tests. They are statements of requirements that each vehicle or item of equipment must meet when tested by the Bureau. Manufacturers are required to exercise due care to ensure that their vehicles will meet the standards if tested by the Bureau, and they are at their own discretion in devising an appropriate testing program for that purpose. If a seat belt manufacturer presents data of tests conducted on webbing taken from rolls, rather than from individual assemblies, and if you are satisfied that such data demonstrates that the webbing would comply with Standard No. 209 when tested according to the procedures of that standard, you may, in our opinion, accept such data for purposes of State approval. I trust that your question has been adequately answered. If you need further clarification we will be glad to provide it. |
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ID: nht70-2.31OpenDATE: 10/23/70 FROM: AUTHOR UNAVAILABLE; R. H. Compton; NHTSA TO: American Motors Corporation TITLE: FMVSS INTERPRETATION TEXT: This is in reply to your letter of October 12, 1976, to Mr. Charles A. Baker of this office in which you requested an interpretation of the phrase "affective projected illuminated area." Class A turn signal lamps are required by Section S3.1 of Federal Motor Vehicle Safety Standard No. 108, which references SAE Standard J588d in Tables I and III for there lamps. The requirements for the illuminated area of a turn signal lamp are specified in J588d as follows: "The effective projected illuminated area measured on a plane at right angles to the side of the lamp must not be less than 12 sq. in. for Class A and 36 sq/ in. for Class B." In the 45 degree visibility requirements, this standard further states "To be considered Visible, the lamp must provide an instructed projected illuminated area of outer less surface, excluding reflex, . . .". Our interpretation of affective projected illuminated area follows; The affective projected illuminated area is that area of the lent measured on a plane as that angles to the axis of the lamp, excluding reflex reflector, noted is not obstructed by an opaque object such as a mounting(Illegible Words) The above interpretation allows the area of rings or other configurations ((Illegible Word) portions) applied in the lane to be considered part of the total effective from, even if this area does not contribute significantly to the total light output. |
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ID: nht70-2.32OpenDATE: 10/29/70 FROM: AUTHOR UNAVAILABLE; R. H. Compton; NHTSA TO: Leaseway Transportation Corporation TITLE: FMVSS INTERPRETATION TEXT: This is in reply to your letter of October 14, 1970, to Mr. Douglas W. Toms, Director, National Highway Safety Bureau requesting an interpretation on the "marker blink switch" relative to Federal Motor Vehicle Safety Standard No. 108. The use of this switch does not violate the requirements of paragraph S3.5 of Standard No. 108, and is permitted by paragraph S3.1.2. Flashing lights for signaling purposes in a highly controversial subject with many proponents for, and many against, their use. This aspect is being clarified in a soon-to-be-published amendment to Standard No. 108, and will be addressed further in a forthcoming notice of proposed rule making on the same standard. |
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ID: nht70-2.33OpenDATE: 10/29/70 FROM: AUTHOR UNAVAILABLE; Lawrence R. Schneider; NHTSA TO: Juno Industries, Inc. TITLE: FMVSS INTERPRETATION TEXT: Your letter of August 26, 1970, concerning the compliance of your cut-van motor home with Federal Motor Vehicle Safety Standard No. 206 - Door Locks and Door Retention Components, has been forwarded to this office for reply. You state that the door in the camper body is located so that no portion of a manikin in any designated seating position would project into the door opening in the side view. If, as it appears, you are correct, the door locks and door retention components on that door are not required to comply with Standard No. 206. You also state that you believe that the doors on the cab comply with Standard No. 206. As a manufacturer of multipurpose passenger vehicles, you are responsible under the National Traffic and Motor Vehicle Safety Act of 1966 for the compliance of the cab doors with Standard No. 206. Although the van may have been manufactured as a truck, it must, when subsequently converted to a multipurpose passenger vehicle, comply with all multipurpose passenger vehicle standards in effect on the date of manufacturer of your motor home. Therefore, you should(Illegible Word) either from the van manufacturer or by your own tests, that the cab doors comply with Standard No. 206. Please let us know if we can be of further assistance. |
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ID: nht70-2.34OpenDATE: 11/03/70 FROM: R. A. DIAZ -- NHTSA; SIGNATURE BY GEORGE C. NIELD TO: B. Borisoff TITLE: FMVSR INTERPRETATION TEXT: Reference is made to your letter of October 14, 1970 to Secretary Volpe regarding our Consumer Information publication. Concerning your comments on stopping distance, the wording used on page 4 is the exact wording of this regulation. The category "Stopping distance in feet with emergency brakes (partial service brake system)" is a generalization of the regulatory wording meant to convey the sense of this requirement to a consumer who may have no engineering background. The paragraph on page 193 paraphrases the regulatory wording. The title "Partial Failure on One System" is, again, meant to convey the meaning to an otherwise uninformed consumer. I trust this clarifies the situation for you. The reason many motorcycles are not listed is the fact that the data was not received in time to be included in the book. I am enclosing copies of the data available for U.S. made motorcycles as you requested. Volume 2, covering the 1971 makes and models will be available approximately November 15, 1970 and can be obtained from the Government Printing Office at a cost of $ 2.00. In addition two (2) new Consumer Aid publications entitled "BRAKES - A Comparison of Braking Performance for 1971 Passenger Cars" and "TIRES - A Comparison of Tire Reserve Load for 1971 Passenger Cars" will also be available at a cost of $ .40 each. Many thanks for your kind words and your interest in our motor vehicle safety program. |
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ID: nht70-2.35OpenDATE: 11/12/70 FROM: AUTHOR UNAVAILABLE; R. H. Compton; NHTSA TO: Department of California Highway Patrol TITLE: FMVSS INTERPRETATION TEXT: This is in reply to your letter of October 21, 1970, to the National Highway Safety Bureau, concerning environmental tests for sealed beam headlamps used on motocycles and motor-driven cycles. Federal Motor Vehicle Safety Standard No. 108 requires that motorcycle and motor-driven cycle headlamps conform to SAE Standard J584. This SAE Standard, in turn, permits optional use of "one 7-in. sealed beam unit or one 5 3/4-in. Type 1 and one 5 3/4-in. Type 2 sealed beau units meeting the requirements of SAE J579". Therefore, unsealed motorcycle and motor-driven cycle headlamps must conform to the vibration, moisture, dust and corrosion test requirements of SAE J584. Glass sealed beau motocycle and motor-driven cycle headlamps, which are designed specifically to conform to the requirements of SAE J584 (including photometric values), and which are not intended for use on other vehicles, must conform to the vibration, moisture and corrosion test requirement of SAE J584. Such test requirements would not, however, be applicable if a manufacturer elected to provide optional headlamps meeting the requirements of SAE J579a. |
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ID: nht70-2.36OpenDATE: 11/24/70 FROM: AUTHOR UNAVAILABLE; Clue D. Ferguson; NHTSA TO: Mercedes-Benz of North America, Inc. TITLE: FMVSS INTERPRETATION TEXT: Thank you for your letter of September 29, 1970, concerning the application of Federal Motor Vehicle Safety Standard No. 206 to the door locks and door retention components on the C-111's gull-wing doors. I appreciate also the design drawings you submitted earlier this month. As Standard 206 presently exists, the door locks and door retention components on the C-111 doors must conform to it. As Rocks and retention components on passenger car side doors that meet the description in the first sentence of S4, they are clearly within the ambit of the standard. The Bureau recognizes that some of the requirements and test procedures in the standard may not be entirely appropriate for side doors of all designs, and is accordingly considering amendments to the standard. If we can be of further assistance, please write. |
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ID: nht70-2.37OpenDATE: 12/02/70 FROM: AUTHOR UNAVAILABLE; L. R. Schneider; NHTSA TO: Charles O. Verrill, Esq. TITLE: FMVSS INTERPRETATION TEXT: In your letter of November 16 you inquire whether the Bureau's interpretation of "overall width" (49 CFR @ 571.21, with reference to Federal Motor Vehicle Safety Standard No. 108) can "embrace the situation where the entire lighting assembly, including the taillamps, stop lamps, and back-up lamps, as well as signal lamps, add to the dimension of the vehicle". Since "overall width" means "the nominal design dimension of the widest part of the vehicle exclusive of signal lamps [and] marker lamps . . . .", the Bureau concurs in your requested interpretation. Taillamps, stop lamps, and back-up lamps are "signal" lamps, and their combined mounting in a fixture which may extend beyond the widest part of a boat trailer does not result in a corresponding increase in the "overall width" of the trailer. |
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ID: nht70-2.38OpenDATE: 12/08/70 FROM: AUTHOR UNAVAILABLE; Rodolfo A. Diaz; NHTSA TO: Ford Motor Company TITLE: FMVSS INTERPRETATION TEXT: This is in reply to your letter of October 26, 1970, submitting a petition for reconsideration concerning Motor Vehicle Safety Standard No. 215, "Child Seating Systems", published September 23, 1970 (35 F.R. 14478). Because of the timing of your petition, it has been treated as a petition for rulemaking pursuant to 49 CFR @@ 553.35, 553.31. Your letter requests that two amendments be made to the standard before its effective date of April 1, 1971. First, you request that paragraph S4.3 be amended to substitute the language proposed for that paragraph in the notice of proposed rulemaking concerning Standard No. 213, also published on September 23, 1970 (35 F.R. 14786). Second, you request that the standard be amended to provide an alternative test procedure that is specified in your petition, as you believe "the test procedure under S4.11.1 and S5 of the standard to be wholly inappropriate for the Ford child restraint system." With reference to your request concerning paragraph S4.3 of the standard, the Bureau did not intend the standard to require all child seating systems to have adjustable components to directly restrain the child. Consequently, the Bureau will not consider that a child seating system without adjustable components to directly restrain the child fails to comply, for that reason, with paragraph S4.3 of the standard. The language of the notice of proposed rulemaking, insofar as it states, "Each child seating system component that is adjustable and is designed to restrain the child directly . . ." is a clarification of the present language. For the proposed amendment to be made effective before April 1, 1971, is therefore unnecessary. Regarding your request for an alternative test procedure, you state in your letter that "using the test procedures in S5.1, the torso block applies an unstabilized, concentrated load on the Tot-Guard shield much like that which would be applied by one cylinder loading another with their axes at 90 degrees to each other." It is not mandatory under S5.1(d) that the load be applied to the torso block at a single point. It may be applied at two or more points as long as the intersection of the load application line and the back surface of the torso block is not more than 8 inches or less than 6 inches above the bottom surface of the torso block. In the case of an unstabilized loading condition, such as that which you state occurs with the Tot-Guard, the load could be applied through a fixture attached to both the top and bottom of the torso block as long as the load application line is within the limits specified. During the test, however, only the torso block and not the attachment fixture may contact the seating system. For the reasons specified above, the amendments you have requested have been found unnecessary and unjustified, and your petition is accordingly denied. |
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.