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: aiam2801OpenMr. William N. Whitley, Vice President, Whitley-Whitley Inc., 26000 Chagrin Boulevard, Shaker Heights, Ohio 44122; Mr. William N. Whitley Vice President Whitley-Whitley Inc. 26000 Chagrin Boulevard Shaker Heights Ohio 44122; Dear Mr. Whitley: This is in reply to your letter of January 17, 1978, in which you aske for a definition of the automobile-mounted camping unit illustrated in Design Patent No. 198,497.; The automobile-mounted camping unit would be classified as a 'Slide-i camper' and would be regulated by the Federal Motor Vehicle Safety Standard No. 126, Truck-Camper Loading. We are enclosing a copy of Safety Standard No. 126 and a copy of an amendment dated April 21, 1978. The complete Federal Motor Vehicles Safety Standards (FMVSS) and Regulations may be purchased from the Superintendent of Documents by using the enclosed subscription order form.; Sincerely, Michael M. Finkelstein, Acting Associate Administrator fo Rulemaking; |
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ID: aiam3713OpenMr. Jim Cowen, Manager, Able Body Company, P.O. Box 1868, Joplin, MO 64802; Mr. Jim Cowen Manager Able Body Company P.O. Box 1868 Joplin MO 64802; Dear Mr. Cowen: This is in reply to your letter of May 26, 1983, petitioning for determination that a noncompliance with Standard No. 302 existing in truck sleeper berths that you manufacture is inconsequential as it relates to motor vehicle safety.; We do not believe that Able Body has the legal responsibility to file petition of this nature. Your description of the company as a manufacturer of 'sleeper berths for over-the-road trucks' indicates that Able Body is a supplier of original equipment which is installed in trucks rather than the manufacturer of the truck itself. While Able Body may have a contractual obligation with truck manufacturers to provide them with evidence of compliance with Standard No. 302, the truck manufacturer itself assumes ultimate responsibility under the National Traffic and Motor Safety Act for compliance with that standard by affixing a label to each truck certifying compliance with all applicable standards. This means that the truck manufacturer has the legal responsibility to notify purchasers and remedy noncompliances in its products involving Standard No. 302, even though the component concerned was produced by another company. As the obligation to notify and remedy rests upon the truck manufacturer, only that party may petition for an inconsequentiality determination.; When noncompliances occur, they must be reported to the agency pursuan to 49 CFR 573 *Defect and Noncompliance Reports*. Under this regulation either a component or a vehicle manufacturer may report a noncompliance to NHTSA if the noncompliance exists only in original equipment of a single vehicle manufacturer. However, if the noncomplying component has been used in the vehicles of more than one manufacturer, the manufacturer of the component and all vehicle manufacturers must file individual noncompliance reports. We have no record that Able Body has filed a Part 573 report on this matter. I enclose a copy of Part 573 for your information.; We would appreciate prompt filing of a Part 573 report by Able Bod and/or relevant truck manufacturer(s). You may advise your customers of their right to file an inconsequentiality petition.; Sincerely, Frank Berndt, Chief Counsel |
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ID: aiam4486OpenW.E. Baldwin, Ph.D. President, K-R Industries 418 Crestwood Avenue Feasterville, PA 19047; W.E. Baldwin Ph.D. President K-R Industries 418 Crestwood Avenue Feasterville PA 19047; Dear Dr. Baldwin: This is in reply to your letter of September 1, 1988 asking for an interpretation of paragraph S4.5.11(e) of Motor Vehicle Safety Standard No. 108. You have developed a center highmounted stop lamp 'containing 5 bulbs, where each bulb is illuminated in sequential order.' You state that the 'time between each lamp illumination is less than 250 ms, providing a steady photometric value, meeting S4.1.1.41(c)', and that 'the red lens of the lamp is steadily illuminated, with the illuminated area moveing (sic) in a back and forth motion.' In your opinion, the invention meets the requirement of S4.5.11(e) that lamps, other than those enumerated, be steady-burning. We cannot provide the interpretation you seek. Under paragraph S4.5.4, 'the stop lamps on each vehicle shall be activated upon activation of the service brakes.' This means that all bulbs providing the center stop lamp signal must be simultaneously activated, not sequentially. In addition, we do not consider a lamp with a moving illuminated area to be one that is steady-burning within the meaning to S4.5.11(e). Sincerely, Erika Z. Jones Chief Counsel; |
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ID: aiam3343OpenMr. H. Miyazawa, Director, Automotive Lighting, engineering Department, Stanley Electric Co., Ltd., 2-9-13, Nakameguro, Meguro-ku, Tokyo 153, Japan; Mr. H. Miyazawa Director Automotive Lighting engineering Department Stanley Electric Co. Ltd. 2-9-13 Nakameguro Meguro-ku Tokyo 153 Japan; Dear Miyazawa: This responds to your August 4, 1980, letter asking whether severa vehicle components would be required to comply with Standard No. 302, *Flammability of Interior Materials.* In particular you ask whether a headlining lamp, a courtesy lamp installed on a door panel, or various pilot indicator lamps and meters installed in the front panel must comply with the requirements.; As you stated in your letter, Section S4.1 of the standard lists th components required to comply with the standard. Further, that section states that materials designed to absorb energy on contact by occupants must comply with the standard. Since the components that you mention are not listed in S4.1 and since they do not appear to be designed to absorb energy on contact by an occupant, we conclude that they are not required to comply with the standard.; Sincerely, Frank Berndt, Chief Counsel |
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ID: aiam0996OpenMr. J.C. Tim Scates, First National Bank Building, 621 Seventeenth Street, Twenty-third Floor, Denver, CO 80202; Mr. J.C. Tim Scates First National Bank Building 621 Seventeenth Street Twenty-third Floor Denver CO 80202; Dear Mr. Scates:This is in reply to your letter of January 25, 1973 concerning the procedures to be followed by your client in the event that a defaulting vehicle owner refuses to disclose the mileage when his vehicle is repossessed.; The Federal Odometer Disclosure Requirements were issued in final for on January 23, 1973, and become effective March 1, 1973. After March 1, your client will be obliged to make a disclosure statement upon resale of the vehicle. If he cannot obtain a statement from the defaulting owner, he will have to advise the buyer of the deficiency in order to protect himself from liability in the event the odometer is found to be wrong. Our regulation does not address this situation directly, but it would appear that the disclosure statement you propose conforms to the basic outline and would afford protection from civil liability under the Act.; Yours truly, Richard B. Dyson, Assistant Chief Counsel |
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ID: aiam1684OpenMr. Ray L. Underwood, F.T.E. Industries, Inc., P.O. Box 7209 Cody Station, 4225 Quinlan, Flint, MI 48507; Mr. Ray L. Underwood F.T.E. Industries Inc. P.O. Box 7209 Cody Station 4225 Quinlan Flint MI 48507; Dear Mr. Underwood: This responds to your November 11, 1974, question whether th Model-FTE468T42 trailer qualifies as a 'heavy hauler trailer' which is not subject to the requirements of Standard No. 121, *Air brake systems*, until September 1, 1976. 'Heavy hauler trailer' is defined in S4. of the standard as follows:; >>>'Heavy hauler trailer' means a trailer with one or more of th following characteristics:; (1) Its brake lines are designed to adapt to separation or extension o the vehicle frame, or; (2) Its body consists only of a platform whose primary cargo-carryin surface is not more than 40 inches above the ground in an unloaded condition, except that it may include sides that are designed to be easily removable and a permanent 'front-end structure' as that term is used in S 393.106 of this title.<<<; From the description you enclosed, it appears that the trailer has primary cargo-carrying surface that is not more than 40 inches above the ground in the unloaded condition, and that it would therefore not be required to meet the standard until September 1, 1976.; Yours truly, Richard B. Dyson, Acting Chief Counsel |
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ID: aiam2102OpenMr. R.E. Ruda, Swan Hose Division, Amerace Corporation, Beal Avenue, Bucyrus, Ohio 44820; Mr. R.E. Ruda Swan Hose Division Amerace Corporation Beal Avenue Bucyrus Ohio 44820; Dear Mr. Ruda: #I am writing to confirm your telephone conversation o July 21, 1975, with Mark Schwimmer if this office, concerning the labeling requirements of Federal Motor Vehicle Safety Standard No. 106-74, *Brake Hoses.* #Your letter of June 12, 1975, explained that you supply hose in lengths as short as 1 1/2 inches. You found it possible to include a complete legend of the information required by S5.2.2 of the standard only by utilizing two lines if printing, parallel to each other and separated by approximately 1/8 inch. As Mr. Schwimmer explained, such a labeling procedure would satisfy the standard's requirements. #I would like to point out, however, that the standard was amended by Notice 18 (40 FR 38159, August 27, 1975), to facilitate the depletion of inventories of brake hose which complies with all requirements except the labeling requirements of S5.2. One effect of that amendment was to delay until September 1, 1976, the requirements that at least one complete legend appear on any hose used in an assembly, regardless of its length. For your convenience, I have enclosed a copy of the notice. #Sincerely, Frank Berndt, Acting Chief Counsel; |
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ID: aiam2552OpenMr. David T. Schellhase, P.O. Box 124, Pompano Beach, Florida 33061; Mr. David T. Schellhase P.O. Box 124 Pompano Beach Florida 33061; Dear Mr. Schellhase: This responds to your February 17, 1977, letter inquiring whether yo may inlay whitewall ring on black tires. You state that in the process a groove is cut around the tire and a white compound is inserted into the groove.; Assuming that you are discussing applying this process to new passenge 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.; Sincerely, Frank A. Berndt, Acting Chief Counsel |
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ID: aiam5297OpenMaurice Hannigan, Commissioner Department of California Highway Patrol P.O. Box 942898 Sacramento, CA 94298-001; Maurice Hannigan Commissioner Department of California Highway Patrol P.O. Box 942898 Sacramento CA 94298-001; "Dear Mr. Hannigan: It has come to our attention that misunderstanding has arisen about a letter we issued on March 31, 1993 to W.C. Burke of your Department. That letter explained the marking responsibilities of a person who installs replacement glass (referred to as glazing in the Federal standard) under section S6.4 of Federal motor vehicle safety standard No. 205, Glazing Materials (49 CFR 571.205, copy enclosed.) On January 12, 1994, Mr. Clarke Harper of this agency's Office of Vehicle Safety Standards and Mr. Marvin Shaw of my staff contacted Mr. Walter Burke and Mr. Kyle Larson of CHP to discuss this matter. This letter is a follow up to that discussion. Based on its understanding of the March 1993 letter, CHP is requiring installers to mark replacement glazing with a number (which the agency refers to as a manufacturer's code mark) and has directed school districts to tell installers of glass to contact NHTSA ' t o obtain a number as required by Standard No. 205 .' Standard No. 205 does not require the typical aftermarket installer to obtain such a number from the agency. We explained in the March 1993 letter that a person who cuts glazing (i.e., a typical installer of aftermarket glazing) must mark the piece with the following information required by section 6 of American National Standard (ANS) Z26: (1) the words 'American National Standard' or the characters 'AS,' (2) a number identifying the item of glazing, (3) a model number assigned by the manufacturer that identifies the type of construction of the glazing material, and (4) the manufacturer's distinctive designation or trademark. Mr. Larson stated that he was under the impression that '(3) a model number assigned by the manufacturer' was a number assigned by NHTSA. As we explained to him, this is not the case. The installer devises his own model number. The only number assigned by NHTSA under Standard No. 205 is the code mark assigned to a manufacturer who 'fabricates, laminates, or tempers the glazing material' (known as a 'prime glazing material manufacturer'). We hope that this clarifies our earlier letter on this subject. If you have any other questions, please contact Mr. Shaw at (202) 366-2992. Sincerely, John Womack Acting Chief Counsel"; |
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ID: aiam0095OpenMr. Warren M. Heath, Commander, Engineering Section, Department of California Highway Patrol, P.O. Box 898, Sacramento, CA 95804; Mr. Warren M. Heath Commander Engineering Section Department of California Highway Patrol P.O. Box 898 Sacramento CA 95804; Dear Mr. Heath: Thank you for your letter of July 1, 1968, to Mr. George C. Nield concerning a clarification of paragraph S 3.4.3 of Federal Motor Vehicle Safety Standard No. 108.; Paragraph S 3.4.3 specifies that, as a minimum, the taillamps shall b illuminated when the headlamps are illuminated, except when the headlamps are being flashed. The phrase 'except when the headlamps are being flashed', permits the vehicle manufacturer to use a separate switch or flasher for illuminating the headlamps only when it would not be appropriate or in the interest of safety to simultaneously illuminate the taillamps and headlamps. In addition to the examples cited in your letter, such devices could also be used for flashing the headlamps on public transit vehicles to indicate an emergency situation.; Since the subject matter of S 3.4.3 is taillamps and since Federa Standard No. 108 is otherwise silent as to headlamp flashing, this matter appears to be within the purview of the California vehicle code.; Thank you for your continued interest in the motor vehicle safet standards.; Sincerely, David A. Fay, Office of Standards on Accident Avoidance Motor Vehicle Safety Performance Service; |
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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.