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: nht72-2.43OpenDATE: 10/11/72 FROM: AUTHOR UNAVAILABLE; R. B. Dyson; NHTSA TO: Monroe Standard, Inc. TITLE: FMVSS INTERPRETATION TEXT: This is in reply to your letter of September 25, 1972, regarding the warning signal required under S5.1.5 of Motor Vehicle Safety Standard No. 121, Air Brake Systems. Your reading of the second sentence of S5.1.5 is partially in error. If the visible low pressure warning signal is provided with a companion audible signal, the visible signal does not have to be within the driver's forward field of view. Under S5.1.5 a manufacturer may choose to install a visible signal within the driver's forward field of view, in which case he may omit the audible signal, or to install the signal outside the driver's forward field of view, in which case he must provide an audible signal. If a manufacturer provides a signal within the forward field of view, he may choose to provide an audible signal as well, but the section does not require him to do so. |
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ID: nht72-2.45OpenDATE: 03/29/72 FROM: AUTHOR UNAVAILABLE; Richard B. Dyson; NHTSA TO: Zecol, Inc. TITLE: FMVSS INTERPRETATION TEXT: In response to your letter of February 28, I enclose a copy of Federal Motor Vehicle Safety Standard No. 116, Motor Vehicle Brake Fluids, which became effective March 1, 1972. Paragraph S5.2 as amended specifies the appropriate labeling for containers of fluid manufactured on and after March 1. If the labels on containers in stock do not meet the new requirements, you may affix a conforming gummed label over them. I recommend that you subscribe to the Federal Register ($ 25.00 per year, from Superintendent of Documents, U.S. Government Printing Office, Washington, D.C. 20402), which contains all Federal regulations as issued or proposed on a daily basis. As a manufacturer in a regulated industry, it is your responsibility to be completely familiar with all applicable regulations. The Superintendent of Documents can also provide you with a subscription service to Federal Motor Vehicle Safety Standards ($ 8.00 per year), updated as new regulations are issued. |
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ID: nht72-3.28OpenDATE: 06/15/72 FROM: AUTHOR UNAVAILABLE; Richard B. Dyson; NHTSA TO: Wayne Transportation Division TITLE: FMVSS INTERPRETATION TEXT: This is in reply to your letter of June 1, 1972, in which you asked whether a bus passenger seat to which you plan to attach seat belts would be required to conform to Motor Vehicle Safety Standard No. 207, Seating Systems, and No. 210, Seat Belt Anchorages. The seat would not be required to conform to either standard. Each expressly exempts bus passenger seats from compliance with its requirements. It is our opinion that if a manufacturer provides a safety device which the applicable standards do not require him to provide, he is not bound to conform to the performance requirements of those standards. Even though no standard is presently applicable, the agency is considering rulemaking action that will establish a standard for bus seating and we strongly urge you to provide the safest possible installation. |
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ID: nht72-3.41OpenDATE: 02/24/72 FROM: AUTHOR UNAVAILABLE; Richard B. Dyson; NHTSA TO: Lempco Industries, Inc. TITLE: FMVSS INTERPRETATION TEXT: This is in reply to your letter of January 18, 1972, on the subject of an automobile dealer's obligations regarding seatbelts in new cars. Motor Vehicle Safety Standard No. 208 requires seatbelts to be installed at all seating positions. Under the requirements of the National Motor Vehicle and Traffic Safety Act, which we administer, it is a violation of the law to sell a vehicle that does not conform to an applicable standard. A dealer may not, therefore, sell an automobile that does not have the required number of seatbelts. Although the act does not prevent the purchaser of a vehicle from removing the belts, after he has completed the purchase, we strongly advise him to leave the belts in and to wear them. A dealer who removes the belts after he has sold the vehicle does not violate the law, but he does his customer a disservice. |
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ID: nht72-3.46OpenDATE: 03/17/72 FROM: J.E. LEYSATH FOR E.T. DRIVER -- NHTSA TO: U.M. Electrical Distributers Ltd. TITLE: FMVSS INTERPRETATION TEXT: This is in response to your letter of March 6, 1972, concerning warning buzzers for the automobile industry. The National Highway Traffic Safety Administration has issued two safety standards which specify warning requirments. These requirements are given in Paragraph S4.4 of Standard 114 and Paragraph S7.3.1 of Standard 208. A copy of these two standards are enclosed for your review and further information. You will note that these standards do not stipulate minimum requirements for the warning devices, and, at the present time, we have no plans to specify such requirements. The data sheet, however, which you enclosed will be useful to us should we specify such requirements in future amendments to these standards. We appreciate your writing to us, and if we can be of any further service, please let us know. |
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ID: nht71-4.20OpenDATE: 10/14/71 FROM: AUTHOR UNAVAILABLE; C. A. Baker for E. T. Driver; NHTSA TO: Forse Cleanamation TITLE: FMVSS INTERPRETATION TEXT: This is in reply to your letter of September 29, 1971, to Mr. J. E. Leysath of this Office requesting information relative to the lighting requirements applicable to your E - Z Tow towing unit. The E-Z Tow unit is a "motor vehicle" as defined by the National Traffic and Motor Vehicle Safety Act of 1966 since it is a "vehicle . . . drawn by mechanical power manufactured primarily for use on the public streets, roads, and highways." However, since it is designed to "tow" rather than to "carry" property, the E-Z Tow unit is not a "trailer" as defined for purposes of the Federal Motor Vehicle Safety Standards. Since it is an unclassified "motor vehicle," the lighting requirements of Federal Motor Vehicle Safety Standard No. 108 are not applicable; therefore, you need only to comply with the lighting requirements of the States in which you sell or use the unit. |
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ID: nht71-4.44OpenDATE: 11/10/71 FROM: AUTHOR UNAVAILABLE; Lawrence R. Schneider; NHTSA TO: Toyota Motor Company, Ltd. TITLE: FMVSS INTERPRETATION TEXT: As indicated to you in the November 1 meeting in Mr. Laskin's office, the seat belt retractor demonstrated by Toyota and shown on page 9 of the attachment to your letter is considered by the National Highway Traffic Safety Administration to be an automatic locking retractor. The classification of a retractor is determined by its operation, not by its design, and the Toyota retractor, however unconventional in design, operates in the manner prescribed for automatic locking retractors. With respect to the test procedure of S5.3(a)(6), it is the intent of the test to load the seat belt assembly in a manner that represents the type of tension encountered in use. It is our opinion that the test set up shown on page 9 of the attachment to your letter is a correct application of the procedure to the Toyota retractor. Please advise us if we can be of further assistance. |
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ID: nht71-5.12OpenDATE: 12/03/71 FROM: AUTHOR UNAVAILABLE; Richard B. Dyson; NHTSA TO: Department of California Highway Patrol TITLE: FMVSS INTERPRETATION TEXT: Your inquiry concerning the certification required of seat belts installed in motor vehicles manufactured after January 1, 1972, has been brought to our attention. Motor Vehicle Safety Standard No. 208, which governs the installation of seat belts, requires belts to conform to Standard No. 209. Since Standard No. 209 is amended effective January 1, 1972, your question is whether a vehicle manufactured after that date must have seat belts that are certified as conforming to the new provisions of Standard No. 209. We construe Standard No. 208 to require only that the belts conform to Standard No. 209 as it was at the time of their manufacture. Thus, a belt manufactured before January 1 that conforms to the contemporaneous (pre-amendment) version of Standard No. 209 may be installed in a vehicle manufactured after that date. A belt manufactured after January 1, must, of course, conform to the amended version of the standard. |
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ID: nht71-5.25OpenDATE: 12/15/71 FROM: AUTHOR UNAVAILABLE; E. T. Driver; NHTSA TO: Ambassador Trailers TITLE: FMVSS INTERPRETATION TEXT: This is in reply to your letter of November 4, 1971, to the Department of Transportation, concerning lighting requirements on your boat trailers. A copy of Federal Motor Vehicle Safety Standard No. 108, "Lamps, Reflective Devices and Associated Equipment" is enclosed for your information. The location of the lamps and reflectors shown on your drawing appears to meet the requirements of Standard No. 108, providing they are mounted to meet the height requirements. Since the width of your trailer is more than 80 inches, front and rear clearance lamps and rear identification lamps are also required as specified in Table I and located as specified in Table II. Combination front and rear clearance lamps are allowed in paragraph S4.1.1.9. There are no other requirements for trailers specified in the Federal Motor Vehicle Safety Standards. Enc. |
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ID: nht71-5.3OpenDATE: 11/18/71 FROM: AUTHOR UNAVAILABLE; Richard B. Dyson; NHTSA TO: Recreational Vehicle Institute, Inc. TITLE: FMVSS INTERPRETATION TEXT: As we have advised Ed Bernett of your office from time to time during the fall, a response to your letter on the treatment of removable foam seat cushions under Standard No. 207 has been under review for some time. Standard No. 207 is essentially a test of the strength of the seat structure. As such it does not prohibit the use of removable seat cushions of the type described in your letter. We consider it to be the intent of the standard, however, that when the momentum of a cushion is transferred in any way to the seat structure during the course of an acceleration in a given direction, the weight of the cushion must be added to the weight of the seat structure in calculating the force to be applied in that direction under 84.2 and 34.3.2. |
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.