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 |
|---|---|
| search results table | |
ID: aiam5508OpenMr. Takashi Tohse Quality Assurance Group Fabricated Glass General Division Asahi Glass Company 2-1-2 Marunouchi Chiyoda-ku, Tokyo 100 Japan; Mr. Takashi Tohse Quality Assurance Group Fabricated Glass General Division Asahi Glass Company 2-1-2 Marunouchi Chiyoda-ku Tokyo 100 Japan; "Dear Mr. Tohse: This responds to your inquiry about whether variou ways of marking your automotive glazing comply with the marking requirements in Federal Motor Vehicle Safety Standard No. 205, Glazing Materials. Specifically, you ask the agency to assess the merits of what you refer to as 'plural company Ids' in your logo mark. By 'plural company Ids,' we assume you mean more than one distinctive designation or trademark. We also assume that you are a 'prime glazing material manufacturer' which the Standard defines as 'one who fabricates, laminates, or tempers the glazing material.' Under Standard No. 205, a replacement windshield is required to be marked with information that includes the prime glazing manufacturer's 'distinctive designation or trademark' and a manufacturer's code mark assigned by this agency. See, S6.1 and S6.2. You first ask, 'Can a manufacturer use different kinds of Ids for different grades of products?' The answer to this question is yes. We understand that what you refer to as 'Ids' is the manufacturer's distinctive designation or trademark. As long as an item of glazing has a manufacturer's distinctive designation or trademark, a manufacturer would comply with this requirement. The Standard does not prohibit a manufacturer from varying this distinctive designation or trademark among its different grades. (We note that each of your products would be marked with the same manufacturer's code mark that is assigned by NHTSA. This code mark will help NHTSA identify the manufacturer of the glazing material for purposes of defect and noncompliance recall campaigns.) Your second question asks 'Can a manufacturer used the same distinctive designation or trademark for two different companies?' The answer is yes. The requirements do not prohibit two companies from sharing a distinctive designation or trademark. As mentioned above, the glazing must be marked with the manufacturer's code mark that identifies the glazing's actual manufacturer. I hope this information is helpful. Please feel free to contact Marvin Shaw of my staff at this address or by telephone at (202) 366-2992 if you have any further questions or need additional information. Sincerely, Philip R. Recht Chief Counsel"; |
|
ID: aiam1818OpenHonorable J. Glenn Beall, Jr., United States Senate, Washington, DC 20510; Honorable J. Glenn Beall Jr. United States Senate Washington DC 20510; Dear Senator Beall: I would like to respond to your February 20, 1975, request fo consideration of Mr. R. L. Herman's views on Standard No. 121, *Air brake systems*. Mr. Herman objects that the National Highway Traffic Safety Administration (NHTSA) may have ignored the majority of comments submitted in response to its recent proposal to delay implementation of the standard, that implementation of the standard should be reconsidered by an activity other than the NHTSA, and that the new brake systems may be less safe than existing systems.; Standard No. 121 was issued as a final rule in February 1971. The NHTS realized that the economic situation in the automotive industry this past fall might justify a postponement of the scheduled January 1, 1975, effective date. In the short time available for review of the standard before its effective dates, the NHTSA issued a proposal, received comments, and made its decision.; The NHTSA concluded that net economic benefit would not be derived fro postponement. The decision was based on evaluation of all the comments, including those concerning the standard's immediate short-term impact on the national economic picture. An important factor in this case was the imminence of the standard and the degree to which financial and employment commitments were made.; As you may know, the President has directed (by Executive Order 11821 that each Federal agency consider the inflation impact of its regulatory actions. At the time of the NHTSA decision on December 31, 1974, final criteria and procedures for implementation of the Order were not yet established. The NHTSA did, however, analyze economic effects of its proposal. The NHTSA has publicly committed itself to continue monitoring the effectiveness of its standard in accordance with its statutory mandate and the President's direction, with a view to identifying any modifications that would lower costs while achieving comparable levels of safety.; An independent evaluation of the standard and its implementation by th Office of the Secretary (of the Department) was recently conducted, and this study supports the NHTSA decision. A copy of a letter regarding that evaluation is enclosed, and it discusses in detail Mr. Herman's concern about the field testing of the new braking components.; Thank you for your interest in motor vehicle safety. Sincerely, James C. Schultz, Chief Counsel |
|
ID: aiam3825OpenLawrence F. Henneberger, Esq., Arent, Fox, Kintner, Plotkin & Kahn, 1050 Connecticut Avenue, N.W., Washington, DC 20036-5339; Lawrence F. Henneberger Esq. Arent Fox Kintner Plotkin & Kahn 1050 Connecticut Avenue N.W. Washington DC 20036-5339; Dear Mr. Henneberger: This is in reply to your letter of September 26, 1983, asking for a interpretation on behalf of your client, Jacobs Manufacturing Company.; You referenced an interpretation of August 31, 1978, which we gave you also on behalf of Jacobs. Your client manufactures a diesel engine retarder system which would be provided a means to warn following drivers when the system was in use. The specific means of warning discussed in the 1978 letter was to connect the retarder activation switch to the hazard warning system, either as original or aftermarket equipment. We concluded that his installation augmented the hazard warning system, and thus did not impair the hazard warning system within the prohibition of paragraph S4.1.3 of Standard No. 108. We also concluded that it would not render inoperative the hazard warning system, and thus was not a violation of the 'anti-tampering' provision of Section 108(a)(2)(A) of the Traffic Safety Act.; Apparently, a customer of Jacobs has asked it to wire its warnin system through the stop lamps. A separate manually-operated switch will be provided. We understand that when the warning system is operational there is no difference of light intensities when the brakes are applied. You have asked us for a re-interpretation, on the basis of these new facts, that the changes retarder warning will not violate either paragraph S4.1.3 or section 108(a)(2)(A). You believe that the warning system is still permissible, because the stop lamps when so used will nevertheless indicate that the vehicle is diminishing its speed by braking, and because of interpretations by this office that retarder controls can be incorporated with the foundation brake controls and activated with the foundation brakes.; We have reviewed the 1978 interpretation allowing use of the retarde system through the hazard warning system, and the two 1974 interpretations with reference to incorporation of supplementary braking devices with foundation controls. We agree with your interpretation that the latter interpretations impliedly require activation of the stop lamps when the supplementary braking devices are used. The agency is not prepared at this time to modify either interpretation, and you may inform your client that there is no Federal legal prohibition against its wiring the retarder to activate the stop lamps when it is in use.; However, we wish to point out an area of potential risk which you client should weigh before proceeding to offer this option and which, if it occurred, could be viewed as an impairment of the stop signal within the prohibition of S4.1.3. Under the Jacobs plan, activation of the stop lamp when the retarder is engaged would indicate only a lessened rate of speed. Because there is no difference in intensity, a following driver would have no indication when the brake was applied to signal a normal or sudden stop, such as might be required when a child or animal runs into the roadway.; If you have any further questions, we shall be happy to answer them. Sincerely, Frank Berndt, Chief Counsel |
|
ID: aiam2737OpenMr. Joe Wall, Assistant Director, Vehicle Inspection Division, Oklahoma Department of Public Safety, 3600 North Eastern, P.O. Box 11415, Oklahoma City, OK 73111; Mr. Joe Wall Assistant Director Vehicle Inspection Division Oklahoma Department of Public Safety 3600 North Eastern P.O. Box 11415 Oklahoma City OK 73111; Dear Mr. Wall: This responds to your letter of December 9, 1977, asking whether th recent amendment of Safety Standard No. 205, *Glazing Materials*, permits the use of plastic glazing in school buses.; The answer to your question is yes. Safety Standard No. 205, as amende December 5, 1977 (42 FR 61465), allows the use of rigid plastic glazing in doors and windows of all buses, including school buses. Please note, however, that plastics cannot be used for bus windshields or in doors or windows to the immediate right or left of the driver.; Sincerely, Joseph J. Levin, Jr., Chief Counsel |
|
ID: aiam4030OpenThomas C. Bielinski, Esq., 33 N. Dearborn Street, Suite 1530, Chicago, IL 60602; Thomas C. Bielinski Esq. 33 N. Dearborn Street Suite 1530 Chicago IL 60602; Re: Bartlett v. Wards Dear Mr. Bielinski: The National Transportation Safety Board has forwarded to us for repl your letter of August 29, 1985, asking for information on standards and other regulations regarding the design and manufacture of mopeds.; This agency, the National Highway Traffic Safety Administration, issue the Federal Motor Vehicle Safety Standards which all motor vehicles must meet upon manufacture and initial sale. 'Moped' is not a defined vehicle category under the safety standards but the defined category of 'motorcycle' covers all two-wheeled vehicles such as mopeds. These standards will be found at Title 49 Code of Federal Regulations Part 571 and the applicability section of each standard (either paragraph S3 or S3) will tell you whether it applies to 'motorcycles'. Standards have been adopted for motorcycle brake hoses, (571.106), lighting, (571.108), mirrors (571.111), vehicle identification number (571.115 and Part 565), brake fluids (571.116), tires (571.119), rims (571.120), braking systems (571.122), controls and displays (571.123) and glazing (571.205). Manufacturers must certify compliance with all applicable Federal motor vehicle safety standards (Part 567).; You will find that sections of some of these standards impose a lesse degree of performance upon 'motor-driven cycles'. These are motorcycles producing 5 horsepower or less, and thus include most mopeds of which we are aware.; The individual States are not preempted from having their own standard for area of performance not covered by Federal standards (for covered areas, however, State standards must be identical), and you may also wish to examine the laws of the jurisdiction in which the moped in your case was licensed or being operated.; A manufacturer is required to file an information statement with th agency within 30 days of commencing production (Part 566). If a vehicle fails to conform to a safety standard or contains a safety related defect, its manufacturer must notify the agency, owners and dealers, and remedy the problem (Part 573 and 577).; I hope that this information is useful to you. Sincerely, Erika Z. Jones, Chief Counsel |
|
ID: aiam1232OpenMr. Gino D'Angelo, Director of State Police, Fiscal Management, New York State Police, Albany, NY 12226; Mr. Gino D'Angelo Director of State Police Fiscal Management New York State Police Albany NY 12226; Dear Mr. D'Angelo: This is in reply to your letter on August 20, 1973, asking that la enforcement vehicles be excluded from a Federal prohibition against headlight flashers.; There is no such prohibition. While paragraph S4.6(b) of Federal Moto Vehicle Safety Standard No. 108 requires headlamps to be steady-burning in use, it also specifically states that 'means may be provided to flash [automatically] headlamps . . . for signalling purposes.' Therefore, manufacturers are not prohibited from equipping vehicles with headlamp flasher units upon customer request.; Yours truly, Richard B. Dyson, Acting Chief Counsel |
|
ID: aiam4460OpenRobert J. Kaufman, Esq. Gingold, Kaufman & Chaiken 400 Perimeter Center Terrace, N.E. Suite 720 Atlanta, GA 30346-1234; Robert J. Kaufman Esq. Gingold Kaufman & Chaiken 400 Perimeter Center Terrace N.E. Suite 720 Atlanta GA 30346-1234; Re: GK&C File "1012-271 Dear Mr. Kaufman: This responds to your recent lette concerning the advice I gave to a company called Auto Accessories, Inc., with respect to the installation of that company's armrests in Volvo 240 automobiles. More specifically, on behalf of your client, a Volvo dealership, you seek clarification of that advice and request copies of any information, e.g., tests or studies, regarding the armrests. I appreciate your client's concern for safety. For your information, I have enclosed a copy of my November 18, 1987 letter to that company, in which the advice was provided. I have also enclosed a copy of the armrest installation instructions that were proposed by Auto Accessories and discussed in my response. Based on your reading of a letter from Auto Accessories to Volvo dealers (enclosed with your letter), you concluded that the armrest installation procedure 'ostensibly was either approved, mandated, or suggested by the Department of Transportation.' As you will see from my November 1987 letter, the Department did not take any of those actions. This Department has no authority under the National Traffic and Motor Vehicle Safety Act (15 U.S.C. 1381 et seq.) to approve or endorse any items of motor vehicle equipment or installation procedures therefor. Instead, the Safety Act puts the responsibility on manufacturers to certify that their products comply with the applicable requirements (15 U.S.C. 1403), and obliges manufacturers, distributors, dealers, and motor vehicle repair businesses not to knowingly render inoperative any devices or elements of design in vehicles that were installed in compliance with applicable safety standards (15 U.S.C. 1397(a)(2)(A)). In keeping with this statutory scheme, this agency did not make a determination in the November 1987 letter or on any other occasion that a dealer following the proposed installation instructions would or would not render inoperative a vehicle's compliance with the safety standards. The agency makes such determinations only in the context of an enforcement proceeding. Instead, my November 18 letter pointed out the element of design that might be rendered inoperative by installing the armrests, and advised Auto Accessories as the manufacturer to carefully examine its instructions to determine whether or not following them would result in a 'render inoperative' violation. It appears from the Auto Accessories letter to dealers that that company believes the installation of its armrest would not result in any violations. Our advice to dealers is essentially the same as the advice we gave to Auto Accessories. Dealers should examine the instructions to determine whether following them would render inoperative a vehicle's compliance with Standard No. 208 or any other standard. You may wish to contact Auto Accessories to learn more about the basis for its apparent belief that the installation of its armrest will not violate any requirements of the Safety Act. As for the tests and studies you requested, again, because of our statutory scheme, we have not conducted any regarding the armrest or its installation. We would do so only in the context of an enforcement proceeding. Please let me know if you have any further questions on this subject. Sincerely, Erika Z. Jones Chief Counsel Enclosure"; |
|
ID: aiam1398OpenMr. Thomas S. Pieratt, Jr., Executive Secretary, Truck Equipment & Body Distributors Assoc., 602 Main Street, Cincinnati, OH 45202; Mr. Thomas S. Pieratt Jr. Executive Secretary Truck Equipment & Body Distributors Assoc. 602 Main Street Cincinnati OH 45202; Dear Mr. Pieratt: This is in response to your letter of January 30, 1974, requestin information concerning whether or not a certification label is required to be furnished by one who installs a snow plow on a completed vehicle prior to the first purchase of the vehicle for purposes other than resale.; An additional certification label is required when a vehicle is altere by the addition of parts that are not readily attachable components. Whether or not the snow plow is a readily attachable item depends in large part on the manufacturer's intent in designing the vehicle.; If the addition of the snow plow necessitated a change in the weigh ratings of the vehicle, there would be an obligation of the alterer's part to attach an additional certification label in accordance with 49 CFR 567.7.; Thank you for your inquiry. Yours truly, Richard B. Dyson, Assistant Chief Counsel |
|
ID: aiam1662OpenMr. Charles J. Calvin, President, Truck Trailer Manufacturers Association, 2430 Pennsylvania Avenue, N.W., Washington, DC 20037; Mr. Charles J. Calvin President Truck Trailer Manufacturers Association 2430 Pennsylvania Avenue N.W. Washington DC 20037; Dear Mr. Calvin: This responds to your October 23, 1974, question in behalf of Steadma Containers, Ltd., asking if Standard No. 121, *Air brake systems*, applies to the Steadman 'liftainer', which is described as a semi-trailer frame capable of carrying 20- and 40-foot cargo containers that are loaded by means of cranes mounted at each end of the semi-trailer. The vehicle is used to move containers in terminal areas and is used on the highway only in relocation to another terminal.; The 'liftainer' is a motor vehicle as that term is defined in th National Traffic and Motor Vehicle Safety Act of 1966, because it uses the highway on a necessary and recurring basis to move between work sites. A discussion of the motor vehicle definition is enclosed for your information. As a motor vehicle, it is subject to the requirements of Standard No. 121 for trailers, effective January 1, 1975.; I have also enclosed a discussion of Standard No. 121's applicabilit to vehicles purchased by Canadians for use between Canadian and United States points. The standard would apply to Steadman trailers if they are purchased for use on U.S. highways.; Yours truly, Richard B. Dyson, Acting Chief Counsel |
|
ID: aiam0970OpenMr. Bernard W. Weber, Executive Vice President, Wesbar Corporation, Box 577, West Bend, WI 53095; Mr. Bernard W. Weber Executive Vice President Wesbar Corporation Box 577 West Bend WI 53095; Dear Mr. Weber: This is in reply to your letter of January 3, 1973, to Mr. Schneide concerning Motor Vehicle Safety Standard No. 108.; Your first question is whether the standard requires items of lightin equipment to be marked according to SAE Standard J759a. The answer is no. A manufacturer, at his option, may mark equipment items with the symbol DOT as a certification of compliance with Standard No. 108. Standard No. 108 neither prohibits nor requires other marking of equipment. The NHTSA proposed in 1972 that equipment be marked in a manner somewhat similar to J759a but no definitive action has been taken on the proposal.; You also asked whether a clearance lamp could be mounted at 45 degree to serve the functions of both a clearance and side marker lamp, and whether it must bear the SAE designation 'PC' indicating its combination function. Your understanding is correct, that a combination lamp mounted at 45 degrees is permissible if it is successfully tested at that mounting angle for conformance to both clearance and side marker requirements. The designation 'PC' is not a current requirement of Standard No. 108 but has been proposed as the required marking symbol in the rulemaking action referred to earlier.; Yours truly, Richard B. Dyson, Assistant Chief Counsel |
|
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.