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: aiam1294OpenL.E. Haight, Esq., Attorney at Law, 805 Idaho Street, P.O. Box 2777, Boise, ID 83701; L.E. Haight Esq. Attorney at Law 805 Idaho Street P.O. Box 2777 Boise ID 83701; Dear Mr. Haight: This is in reply to your letter of September 21, 1973, concerning you desire to disconnect the interlock system on your new car.; The dealer who sold you the car was required to have the interloc working at the time of sale pursuant to section 108(a)(1) of the National Traffic and Motor Vehicle Safety Act (15 U.S.C. 1397(a)(1)). However, section 108(b)(1) of the Act (15 U.S.C. 1397(b)(1)), provides that the requirements of 108(a)(1) do not apply after the first purchase of the vehicle for purposes other than resale. As a purchaser who intends to use the vehicle, you are therefore not subject to the requirements of the Act and may disconnect the interlock.; Despite the absence of legal sanctions for disconnecting the interlock we would hope that you could find a way to adjust the belt so that it could be worn without aggravating your bursitis. The physical sanctions for an unbelted person in a crash can be serious indeed.; Sincerely, Richard B. Dyson, Assistant Chief Counsel |
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ID: aiam1110OpenMr. William Eriksen, Anderson-Alford, Seventh at D Streets, P.O. Box AA, Eureka, CA; Mr. William Eriksen Anderson-Alford Seventh at D Streets P.O. Box AA Eureka CA; Dear Mr. Eriksen: This is in reply to your letter of April 3, 1973, inquiring whethe there are licenses and forms that you must obtain before you may install old truck bodies on new trucks.; Persons who install used truck bodies on new trucks are generall considered to be 'final-stage manufacturers' under NHTSA Certification regulations (49 CFR 567, 568). These regulations require final-stage manufacturers of multi-stage vehicles to certify the conformity of such vehicles to all applicable motor vehicle safety standards. Certification is accomplished by affixing a label to the vehicle. The requirements for both the location and content of the label are contained in the Certification regulations, and you may obtain copies of these regulations as indicated on the enclosed, 'Where to Obtain Motor Vehicle Safety Standards and Regulations'.; There are no licensing requirements, nor specified forms you mus complete before you undertake these manufacturing operations. However, the NHTSA does have requirements, (Part 566, 'Manufacturer Identification', copy enclosed) that require you to submit certain information regarding your company within 30 days after commencing manufacture.; Yours truly, Richard B. Dyson, Assistant Chief Counsel |
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ID: aiam1109OpenMr. William Eriksen, Anderson-Alford, Seventh at D Streets, P.O. Box AA, Eureka, CA; Mr. William Eriksen Anderson-Alford Seventh at D Streets P.O. Box AA Eureka CA; Dear Mr. Eriksen: This is in reply to your letter of April 3, 1973, inquiring whethe there are licenses and forms that you must obtain before you may install old truck bodies on new trucks.; Persons who install used truck bodies on new trucks are generall considered to be 'final-stage manufacturers' under NHTSA Certification regulations (49 CFR 567, 568). These regulations require final-stage manufacturers of multi-stage vehicles to certify the conformity of such vehicles to all applicable motor vehicle safety standards. Certification is accomplished by affixing a label to the vehicle. The requirements for both the location and content of the label are contained in the Certification regulations, and you may obtain copies of these regulations as indicated on the enclosed, 'Where to Obtain Motor Vehicle Safety Standards and Regulations'.; There are no licensing requirements, nor specified forms you mus complete before you undertake these manufacturing operations. However, the NHTSA does have requirements, (Part 566, 'Manufacturer Identification', copy enclosed) that require you to submit certain information regarding your company within 30 days after commencing manufacture.; Yours truly, Richard B. Dyson, Assistant Chief Counsel |
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ID: aiam0434OpenMr. W. Glenn Pracejus, Manager, Electrical/Electronic Division, Electrical Testing Laboratories, Inc., 2 East End Avenue, New York, NY, 20021; Mr. W. Glenn Pracejus Manager Electrical/Electronic Division Electrical Testing Laboratories Inc. 2 East End Avenue New York NY 20021; Dear Mr. Pracejus: Thank you for your letter of September 8, 1971, concerning the recen amendment of Standard 108 concerning turn signal and hazard warning flashers (36 F.R. 17343, August 28, 1971).; You noted that test-condition temperatures are listed withou tolerances, and asked what tolerance is acceptable for testing.; In the case of motor vehicle safety standards, the testing that manufacturer may perform or have performed on its products is not an end in itself, but is done to enable the manufacturer to certify that the products meet the required performance levels under the specified conditions. Thus, the requirement that a product meet or exceed certain values at 75 degrees F. refers to a legal conclusion that is to be drawn from appropriate testing, and no tolerance is necessary or appropriate in the text of the standard. In practical terms, it is up to the manufacturer to determine what tests will enable him to certify his products as conforming. Normally, this is done by testing his products under slightly more adverse conditions than those specified in the standard. If, for example, higher temperatures constitute more adverse conditions for a flasher, the laboratory should test at a temperature slightly higher than that specified. In sum, the testing should be sufficient to support the *conclusion* that, if tested under the specified conditions, the product would perform as required.; Sincerely, Lawrence R. Schneider, Chief Counsel |
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ID: aiam0206OpenMr. A. J. Macho, Administrative Assistant, Holan, Division of Ohio Brass Company, 4100 W. 150th Street, Cleveland, OH 44135; Mr. A. J. Macho Administrative Assistant Holan Division of Ohio Brass Company 4100 W. 150th Street Cleveland OH 44135; Dear Mr. Macho: This is in reply to your letter of January 19, 1970, in which you aske whether section 371.13, Labeling of Chassis-Cabs, requires chassis-cab manufacturers to indicate the date of manufacture by month, day and year, or whether month and year alone is sufficient.; The wording of the section is 'date of manufacture', without furthe elaboration. While in most contexts this phrase refers to a specific day, the present scheme of labeling and certification leads us to the conclusion that the month and year will be sufficient to satisfy the intent of the regulation.; The main regulator purpose of the requirement is to make it clear whic standards are applicable to the chassis cab and therefore to the complete vehicle under our ruling. A similar purpose is fulfilled by the date-of-manufacture requirement in the Certification Regulations, 49 CFR Part 367, and there the requirement is explicitly stated as month and year only. It is the practice of the National Highway Safety Bureau to make standards effective on the first day of a month, and therefore it is unnecessary to require manufacturers to incur the extra expense of a daily label change.; We are pleased to be of assistance. Sincerely, Lawrence R. Schneider, Assistant Chief Counsel fo Regulations; |
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ID: aiam1511OpenMr. Ronald J. Hansing, Project Engineer, The Adams & Westlake Company, 1025 North Michigan Street, Elkhart, IN 46514; Mr. Ronald J. Hansing Project Engineer The Adams & Westlake Company 1025 North Michigan Street Elkhart IN 46514; Dear Mr. Hansing: This is in reply to your letter of April 16, 1974, concerning a interpretation of the requirements of Motor Vehicle Safety Standard No. 217, Bus Window Retention and Release' (49 CFR 571.217). You appear to ask whether bus windows containing tempered glass must meet the release requirements of paragraph S5.3.2 after (as well as before) the retention test required by S5.1 when the glass breaks during the retention test. You state that tempered glass, once broken, is easily removed from the entire lite by touch, implying that when this is the case there is no longer a need for any release mechanism to be further tested.; Paragraph S5.3.2 requires the release mechanism to meet specifie requirements both before and after the window retention test of S5.1 irrespective of the glazing material used in the lite. Consequently, release mechanisms for windows of tempered glass must conform to the requirements even though the glass may be broken during the retention test.; While your argument that the requirement seems unnecessary whe tempered glass is used is not without some basis, it is also quite likely, in our view, that bus passengers in a crash may be ignorant of the quality of tempered glass to which you refer and thus still attempt to operate the emergency exit using its release mechanism.; Yours truly, Richard B. Dyson, Assistant Chief Counsel |
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ID: aiam2045OpenMr. Guy A. Catherine, General Sales Manager, Kleber Corporation, 91-31 Queens Blvd. New York, N.Y. 11373; Mr. Guy A. Catherine General Sales Manager Kleber Corporation 91-31 Queens Blvd. New York N.Y. 11373; Dear Mr. Catherine: #This is in response to your letter of June 3 1975, asking whether it is permissible to import into this country tire designed exclusively for racing purposes. #Tires designed to be used exclusively on racing vehicles, *i.e.*, vehicles other than 'motor vehicles' within the meaning of the national Traffic and Motor Vehicle Safety Act, are not regulated by the Federal motor vehicle safety standards, and may be imported. The labeling that you propose to use appears to be appropriate to warn users of their intended purpose. Manufacturers of such equipment should take all reasonable steps to ensure that their products are not misused. #Yours truly, Richard B. Dyson, Assistant Chief Counsel; |
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ID: aiam1766OpenMr. John T. Clark,GENALCO, Inc.,322 Reservoir Street,Needham Heights, Massachusetts 02194; Mr. John T. Clark GENALCO Inc. 322 Reservoir Street Needham Heights Massachusetts 02194; Dear Mr. Clark:#Please forgive the delay in responding to your lette of September 19, 1974, requesting a 'manufacturers designation' for the air brake hose assemblies which you manufacture.#S5.2.4(b) of Federal Motor Vehicle Safety Standard No. 106-74, *Brake Hoses*, was amended on January 29, 1974 (39 FR 3680, Docket No. 1-5, Notice 9), and again on February 26, 1974 (39 FR 7425, Docket No. 1-5, Notice 10).#In place of an assemble's code number, assigned by the National Highway Traffic Safety Administration, S5.2.4(b) of the standard now requires:#>>>A designation that identifies the manufacturer of the hose assembly, which shall be filed in writing with: Office of Standards Enforcement, 'Brake Hose Identification,' National Highway Traffic Safety Administration, 400 Seventh Street S.W., Washington, D.C. 20590. The marking may consist of a designation other than block capital letters required by S5.2.4.<<<#The designation, 'GENALCO, INC.', as depicted in your letter, already satisfies this requirement. This designation is now on file in the Office of Standards Enforcement.#Please note that the symbol DOT and the date of assembly are still required by the third sentence of S5.2.4 to appear in block capital letters and numerals at least one-eighth of an inch high. Please note also that use of the band is required on assemblies manufactured on or after March 1, 1975, and prohibited on assemblies manufactured before that date.#Yours truly,Richard B. Dyson,Acting Chief Counsel; |
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ID: aiam0723OpenMr. T. C. McLaughlin, McLaughlin Equipment Company, Box 2765/320-27th Street, Fargo, NC 58102; Mr. T. C. McLaughlin McLaughlin Equipment Company Box 2765/320-27th Street Fargo NC 58102; Dear Mr. McLaughlin: This is in further reply to your letters to the National Transportatio Safety Board and the Secretary of Commerce that have been referred to this office.; In your letter to the National Transportation Safety Board you discus the remounting of old school bus bodies on new truck chassis and ask, 'what are the implications of a body shop taking the responsibility of modifying the vehicle?' It is assumed that when you refer to modifying you mean remounting a used school bus body on a new chassis.; Persons who mount used bodies on new chassis are considered to b manufacturers within the meaning of the National Traffic and Motor Vehicle Safety Act and specifically a final stage manufacturer as defined in Part 568 of Title 49 of the Code of Federal Regulations.; We appreciate your bringing this situation to our attention an presently have the matter under investigation.; If you are aware of any one currently involved in this type of busines who might not be aware of their responsibilities, please furnish specific details.; I am enclosing the following pertinent publications: >>>1. National Traffic and Motor Vehicle Safety Act. 2. Notice of Publications Change. 3. Part 566 of Title 49 of the Code of Federal Regulations Manufacturer Identification.; 4. Part 567 - Certification. 5. Part 568 - Vehicles Manufactured in Two or More Stages. 6. Part 573 - Defect Reports. 7. Part 574 - Tire Identification.<<< If you have further questions, I will be pleased to answer them. Sincerely, Francis Armstrong, Director, Office of Standard Enforcement, Motor Vehicle Programs; |
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ID: aiam1560OpenMr. David E. Martin, Manager,Automotive Safety Engineering,General Motors Corporation,Warren, Michigan 48090; Mr. David E. Martin Manager Automotive Safety Engineering General Motors Corporation Warren Michigan 48090; Dear Mr. Martin:#This responds to General Motors' July 10, 1974 request for interpretation of paragraph S3., *Application*, of Standard No. 106-74, *Brake hoses*, relative to brake booster hose. You refer to language in the preamble to Docket No. 1-5 Notice 11, published June 28, 1974 (39 FR 24012), which stated:#>>>The NHTSA has concluded that the difference in requirements for the hydraulic booster system justifies special performance requirements for this application. Until these requirements are developed, hydraulic brake booster hose running from pump to accumulator will be considered to be exempt from the requirements of this standard. Hose running from accumulator to booster will also be exempted if redundant booster is provided.<<<#This language exempts hoses used in certain functions, but not all. Clearly, booster hose running from accumulator to booster without redundant boost would not be exempt. Therefore, your conclusion that Standard No. 106-74 does not apply to any hydraulic brake booster hose, hydraulic brake booster hose end fittings, or hydraulic brake booster hose assemblies is overbroad and for that reason incorrect.#We suggest you describe in another letter the booster applications in General Motors vehicles which are not clearly categorized by the Notice 11 language. We will then be able to tell you whether or not they are subject to the requirements of Standard No. 106-74.#Yours truly,Richard B. Dyson,Acting 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.