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: nht72-1.19OpenDATE: 02/11/72 FROM: AUTHOR UNAVAILABLE; R. B. Dyson; NHTSA TO: Salt Lake Auto Auction TITLE: FMVSS INTERPRETATION TEXT: This is in reply to your letter of January 5, 1972, inquiring whether you may inlay whitewall rings on black tires. You state that in the process a narrow strip of black rubber around the tire is buffed or ground off and replaced with a strip of whitewall which is bonded or vulcanized to the tire in its place. Assuming that you are discussing applying this process to new passenger car tires, whether the process is permissible depends upon whether or not it adversely affects the tire's compliance with Motor Vehicle Safety Standard No. 109, "New Pneumatic Tires," which prescribes performance requirements for all passenger car tires sold in the United States. A copy of the standard is enclosed. If after using the process the tire will not comply with Standard No. 109, the use of the process is prohibited, and its use can result in the imposition of civil penalties of up to $ 1,000 per tire and of other sanctions as well (15 U.S.C. 1397(a)(1), 1398, 1399). In addition, it is the responsibility of the one who wishes to use the process to determine whether it will cause the tires to fail the standard. |
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ID: nht72-1.47OpenDATE: 12/14/72 FROM: AUTHOR UNAVAILABLE; Richard B. Dyson; NHTSA TO: Kettler of America, Inc. TITLE: FMVSS INTERPRETATION TEXT: A review of correspondence we sent you on October 6, 1972, (in response to your letter of September 26, 1972, concerning child seating systems you plan to import), has revealed that one statement we made should be clarified. In the second paragraph of our letter we stated that each "seat must be labeled or tagged with a certification that it conforms to all applicable Federal motor vehicle safety standards." Standard No. 213 (49 CFR 571.213), which applies to child seating systems, does require each child seating system to be labeled with information regarding its safe use, and we refer you to the standard for these requirements. However, with respect to certification, manufacturers are not limited to the method specified in our October 6, 1972, letter (viz., attaching a label to the seat), but may certify in other ways as well. For example, Section 114 of the National Traffic and Motor Vehicle Safety Act (15 U.S.C. 1403), on which the certification requirement is based, states that the certification may also be placed on the outside of the container in which the item is delivered. We regret that our former letter was incomplete in this regard. |
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ID: nht72-1.7OpenDATE: 07/27/72 FROM: AUTHOR UNAVAILABLE; L. R. Schneider; NHTSA TO: Ford Motor Company TITLE: FMVSS INTERPRETATION TEXT: This is in reply to your letter of June 20, 1972, to Mr. Toms concerning general reference material in support of the proposals contained in Docket No. 70-27. Hydraulic Brake Systems. You ask that the NHTSA place in the file "The supporting data upon which the test sequence is based as well as the data used to determine the performance values based on the sequence." The proposed test sequence is based primarily upon the test sequence of standard No. 105, which is that of SAE Recommended Practice J937 incorporated by reference. Parking brake lightly loaded vehicle, inoperative brake power assist unit, and partial failure tests not included in J937, were placed in the sequence in the order that appeared, in the judgment of agency personnel, most likely to provide realistic and undistorted results. The sequence, of course, is subject to revision on the same basis in the forth-coming final rule. General reference material in the Docket includes data from braking tests of eighteen 1970 automobiles, NBS Technical Note 557, "The Brake Pedal Forces Capability of Adult Females," and SAE 720032, "Evaluation of the Use of Automotive Braking Systems During a 7300 Mile Cross-Country Trip." |
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ID: nht72-3.24OpenDATE: 07/25/72 FROM: AUTHOR UNAVAILABLE; Richard B. Dyson; NHTSA TO: 5-J Manufacturing TITLE: FMVSS INTERPRETATION TEXT: This is in response to your letter of June 20, 1972, requesting copies of Department of Transportation requirements regarding the manufacture of small boats, truck camper shells, camping trailers, and boat trailers. The NHTSA does have requirements regarding some of these components. All truck campers are required to conform to Motor Vehicle Safety Standard No. 205, "Glazing Materials," while those campers designed for mounting on incomplete vehicles (as distinguished from those mounted on pick-up trucks) that are manufactured after September 1, 1972, must conform to Motor Vehicle Safety Standard No. 206, "Door Locks and Door Retention Components." Camping and boat trailers must conform to Standard No. 108, "Lamps, Reflective Devices, and Associated Equipment." In addition, manufacturers of these products (campers, trailers, etc.) must certify that their products conform to the standards in the manner set forth in the Certification regulations (49 CFR Parts 567, 568). Information on how to obtain copies of NHTSA requirements is enclosed. We have referred your request for rules and regulations regarding the manufacture of small boats to the United States Coast Guard, and have requested that they respond directly to you. |
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ID: nht72-3.32OpenDATE: 05/08/72 FROM: AUTHOR UNAVAILABLE; Richard B. Dyson; NHTSA TO: Stylar Industries Inc. TITLE: FMVSS INTERPRETATION TEXT: This is in reply to your letter of March 22, 1972, on the subject of the application of Motor Vehicle Safety Standard No. 207 to the type of swivelling seat manufactured by your company. We understand from your letter that you are concerned about the type of swivelling seat that is not continuously fastened to its base and that can therefore come loose in a rollover accident. To avoid this problem, you have designed your seat with a stud bolt that links the seat to its base regardless of the amount of rotation. Your question to us is whether removal of the stud bolt would cause the seat not to conform to Standard 207. The answer to your question depends in part on whether the seat without the bolt would be able to meet the applicable strength requirements of the standard. Removal of the stud belt would not, in itself, cause the seat not to conform to the standard. The seat would conform to S4.3 if the seat were to lock itself by means other than the bolt when returned to the forward facing position. |
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ID: nht71-3.33OpenDATE: 07/14/71 FROM: AUTHOR UNAVAILABLE; C. A. Baker for E. T. Driver; NHTSA TO: Airstream Technical Center TITLE: FMVSS INTERPRETATION TEXT: This is in response to your letter of June 25, 1971, to Mr. Douglas W. Toms, Acting Administrator, National Highway Traffic Safety Administration, concerning lamp locations proposed for your 1972 Airstream trailer. Federal Motor Vehicles Safety Standard No. 108, as amended October 31, 1970 and February 3, 1971, effective January 1, 1972, requires that clearance lamps be mounted to indicate the overall width and as near the top as practicable. Paragraph S4.3.1.5 permits optional mounting height of rear clearance lamps when the rear identification lamps are mounted at the extreme height of a vehicle. The front and rear clearance lamps mounted as shown on your drawing 10033, revision C, do not appear to meet these location requirements. These lamps could be mounted higher than shown and still indicate the overall width of the trailer at locations other than the upper right and left corners, perhaps as high as the front and rear windows. In addition, the side reflex reflectors are to be located as far to the front and rear of the vehicle as practicable. Neither the front nor rear side reflex reflectors shown on the subject drawing appear to meet this requirement. |
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ID: nht71-3.49OpenDATE: 07/22/71 FROM: AUTHOR UNAVAILABLE; Lawrence R. Schneider; NHTSA TO: Recreational Vehicle Institute TITLE: FMVSS INTERPRETATION TEXT: By letter of May 26, 1971, you requested our interpretation of S7.2.3 of Standard No. 208, Occupant Crash Protection, as it affects motor homes and campers that have a forward control configuration. The section provides that forward control vehicles under 10,000 pounds GVWR manufactured after August 15, 1977, may continue to use seat belt assemblies and used not provide passive protection, but that motor homes and vehicles carrying chassis-mount campers must provide passive protection, at least in head-on impacts. Your question is whether a motor home or chassis-mount camper that is also a forward control vehicle must provide passive protection. The exemption granted by S7.2.3 to forward control vehicles was based on the difficulties inherent in providing adequate passive protection for(Illegible Word) vehicles, regardless of their anticipated use. If a forward control vehicle is manufactured in the form of a motor home or camper, the exemption continues to apply and such a vehicle would not be required to conform to the passive protection requirements of S4.1.2.2. Please advise us if you have further questions on this subject. |
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ID: nht71-4.29OpenDATE: 10/22/71 FROM: AUTHOR UNAVAILABLE; Lawrence R. Schneider; NHTSA TO: Nissan Motor Company, Ltd. COPYEE: MR. HITCHCOCK; MR. WOMACK; MR. DYSON; DT TITLE: FMVSS INTERPRETATION TEXT: This is in reply to your letter of September 15, 1971, in which you posed two related questions concerning the use of passive seat belt systems to meet the requirements of S4.1.2.2 of Standard No. 208. The passive seat belt section S4.5.3, was added by the notice of July 8, 1971, "to make it clear that redundant active belts need not be used if passive belts are used to meet any option requiring Type 1 or Type 2 belts." If you choose to install a passive belt system, you do not have to provide a separate active system. In response to your second question, S4.5.3 expressly provides that a passive seat belt assembly may be used in place of a seat belt assembly that conforms to the warning system requirements of S7.3. If a passive seat belt conforming to S4.5.3 is used to meet the requirements of S4.1.2.2, it must comply with paragraph (b) of S4.1.2.2 but need not comply with paragraph (a), (c), or (d). Please advise us if your questions have not been adequately answered. |
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ID: nht71-4.40OpenDATE: 11/05/71 FROM: AUTHOR UNAVAILABLE; C. A. Baker for E. T. Driver; NHTSA TO: Truck-Lite Company TITLE: FMVSS INTERPRETATION TEXT: This is in reply to your letter of October 14, 1971, to Mr. Lewis Owen of this Office concerning an interpretation regarding your Truck-Lite No. 127 License plate light. The requested interpretation concerns the 8 degree incident light angle specified in SAE J587, "License Plate Lamps," as follows: "When a single lamp is used to illuminate the plate, the lamp and license plate holder shall bear such relation to each other that at no point on the plate will the incident light make an angle of less than 8 deg to the plane of the plate." Since the 8 degree incident light angle is also a requirement of Federal Motor Vehicle Safety Standard No. 108, all license plate lamp designs must conform to it. It is our position that the angle be measured from the optical center of the lens; therefore, the Electrical Testing Laboratories' position is valid. That is, the incident light angle of your lamp, without the paint shield and when mounted as it will be installed on the vehicle, is below the 8 degree minimum requirement. |
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ID: nht71-5.42OpenDATE: 10/14/71 FROM: E. T. DRIVER -- NHTSA; SIGNATURE BY CHARLES A. BAKER TO: Cox Tire Machinery Company, Inc. TITLE: FMVSS INTERPRETATION TEXT: Your letter of September 29, 1971, to the National Highway Traffic Safety Administration requesting an interpretation of Federal Motor Vehicle Safety Standard No. 117, has been referred to this office for reply. Within S5 of Standard No. 117, it states that retreaded tires must conform to S4.2.1 of Standard No. 109. S4.2.1 of Standard No. 109 requires a treadwear indicator that will provide a visual indication that the tire has worn to a tread depth of 1/16 inch. For your information, we have enclosed copies of Standards No. 109 and No. 117. ENCLS. COX Fire Machinery Company, Inc. SEPTEMBER 29, 1971 Highway Safety Bureau Federal Highway Administration Gentlemen: Our company is engaged in the sale of retreading equipment and in this business we are constantly calling on tire dealers. A number of our customers have asked whether after retreading standards go into effect will wear indicators be necessary in retreaded tires. I would appreciate an interpetation of the MVSS 117 in this regard. Yours very truly, J. T. Flynt President |
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.