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: aiam2796OpenMr. Tom Caine, Esq., The Goodyear Tire & Rubber Company, Akron, Ohio 44316; Mr. Tom Caine Esq. The Goodyear Tire & Rubber Company Akron Ohio 44316; Dear Mr. Caine: This responds to your March 16, 1978, letter asking about th responsibility for compliance with the Federal motor vehicle safety standards when previously certified tires are modified by the addition of white sidewalls.; In your first question, you ask whether the person who modifies th tire must recertify it for compliance with safety requirements. The answer to your question is no. A modifier of a tire is not considered a manufacturer as that term is defined in the National Traffic and Motor Vehicle Safety Act of 1966 (15 U.S.C. 1381 *et seq.*). A modifier's status is analogous to that of an alterer of a previously certified motor vehicle, there are no labeling or certification requirements for alterers of motor vehicle equipment. Persons who modify previously certified motor vehicle equipment are required to ensure that their modification does not render inoperative any device or element of design installed in compliance with a safety standard.; Since the modifier of previously certified motor vehicle tires has n labeling or certification requirements, the answer to your second question whether it would be required to obtain a manufacturer's identification code mark is no. Only a manufacturer or retreader of motor vehicle tires need obtain such identification marks.; In you final question, you ask who would be responsible for th registration of these modified tires. The original tire manufacturer would be required to conduct the tire registration program. Your assert that this might cause confusion in tire recalls since manufacturers might indicate that blackwall tires are being recalled when, in fact, some whitewall would be included. Our regulation requires that tires be identified in a recall by their serial number. We are not aware of any instance where recalled tires serial have been additionally identified as 'blackwall' by the manufacturers. Thus, although the problem you describe could conceivably occur, we at this time have no basis for viewing it as a real threat to effective recall campaigns.; Sincerely, Joseph J. Levin, Jr., Chief Counsel |
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ID: aiam3133OpenMr. R. W. Hildebrandt, Group Director-Engineering, Bendix Corporation, 901 Cleveland Street, Elyria, OH 44035; Mr. R. W. Hildebrandt Group Director-Engineering Bendix Corporation 901 Cleveland Street Elyria OH 44035; Dear Mr. Hildebrandt: This responds to your September 20, 1979, letter asking the Nationa Highway Traffic Safety Administration (NHTSA) to give you written confirmation that your tandem axle trailer brake system complies with Standard No. 121, *Air Brake Systems*.; The NHTSA does not provide advance determinations of compliance wit the agency's safety standards. It is the manufacturer's responsibility to test for and certify the compliance of its vehicles or equipment. The agency cannot always tell by diagrams and word descriptions whether a system will or will not comply with applicable safety standards. Compliance of a braking system, such as yours, can only be determined when tested on a completed vehicle.; Our technical staff has reviewed the diagrams and the letter that yo submitted. In their opinion, your system appears to comply with the requirements of the standard. However, this is merely an opinion based upon your submission and does not bind the agency in any way should your device fail any compliance tests conducted by the agency.; Sincerely, Frank Berndt, Chief Counsel |
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ID: aiam3318OpenMr. Dennis Newton, School Pupil Transportation, Kansas Department of Transportation, State Office Building, Topeka, KS 66612; Mr. Dennis Newton School Pupil Transportation Kansas Department of Transportation State Office Building Topeka KS 66612; Dear Mr. Newton: This responds to your June 2, 1980, letter asking whether a school bu that is to be sold to a school district in your State will meet the Federal minimum requirements applicable to gross axle weight ratings (GAWR) and gross vehicle weight ratings (GVWR).; To the best of my knowledge, the Federal government has no minimu specifications for GAWR or GVWR. Certainly, this agency does not specify minimum weight ratings. Our only requirement is that the GAWR and GVWR be appropriate for the size and weight of a vehicle taking into consideration the type of equipment installed on it. From the information that you have provided us, we cannot say that the vehicle in question would or would not comply with that requirement. It is the responsibility of the vehicle manufacturer to certify that its vehicles comply with the Federal safety standards. No school bus manufacturer can sell you a school bus that they know will not comply with the requirements.; Sincerely, Frank Berndt, Chief Counsel |
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ID: aiam3319OpenMr. Dennis Newton, School Pupil Transportation, Kansas Department of Transportation, State Office Building, Topeka, KS 66612; Mr. Dennis Newton School Pupil Transportation Kansas Department of Transportation State Office Building Topeka KS 66612; Dear Mr. Newton: This responds to your June 2, 1980, letter asking whether a school bu that is to be sold to a school district in your State will meet the Federal minimum requirements applicable to gross axle weight ratings (GAWR) and gross vehicle weight ratings (GVWR).; To the best of my knowledge, the Federal government has no minimu specifications for GAWR or GVWR. Certainly, this agency does not specify minimum weight ratings. Our only requirement is that the GAWR and GVWR be appropriate for the size and weight of a vehicle taking into consideration the type of equipment installed on it. From the information that you have provided us, we cannot say that the vehicle in question would or would not comply with that requirement. It is the responsibility of the vehicle manufacturer to certify that its vehicles comply with the Federal safety standards. No school bus manufacturer can sell you a school bus that they know will not comply with the requirements.; Sincerely, Frank Berndt, Chief Counsel |
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ID: aiam0236OpenMr. H. W. Sullivan, Commissioner, Department of California Highway Patrol, Post Office Box 898, Sacramento, CA 95804; Mr. H. W. Sullivan Commissioner Department of California Highway Patrol Post Office Box 898 Sacramento CA 95804; Dear Mr. Sullivan: Thank you for your letter of March 2, 1970, petitioning for amendment to Federal motor vehicle safety standard No. 205-Glazing Materials. I apologize for the delay in this response to your petition.; The first amendment you propose would require each manufacturer to mar each piece of glazing material with his name, the model number and 'AS' classification. A manufacturer electing the certification alternative now in S3.4 must provide the same information you request, except that a code number is substituted for the manufacturer's name. In this connection, the Director of the National Highway Safety Bureau is considering the issuance of a notice of proposed rule making which would require all manufacturers of glazing materials to adopt the certification method in S3.4. Consequently, while we are not granting your petition on identification requirements, we are actively considering your suggestions for future rule making.; The second amendment you propose would add to the standard a definitio of 'area requisite for driving visibility.' Subsequent to the writing of your letter, the Director issued an advance notice of proposed rule making concerning a new standard, Direct Fields of View. In this notice, a copy of which is enclosed for your convenience, the Director announced that he was; >>>considering the establishment of performance requirements for (1 direct fields of view outside the vehicle in *all* directions to provide adequate visibility for the driver from specified eye reference loci, (2) light transmission characteristics (including maximum levels of tinting) of vehicle glazing materials, and (3) shade band boundaries of vehicle glazing materials. (Emphasis added.)<<<; Requirements developed with regard to items (2) and (3) would superced provisions regarding shade band boundaries and tinting in standard No. 205. If this new standard is issued, it will deal with the problem which you mention.; We would welcome any additional comments you may have on these matters. Sincerely, Rodolfo A. Diaz, Acting Associate Director, Motor Vehicl Programs; |
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ID: aiam3477OpenMr. John Kime, Century Motor Coach, 59140 County Road 3 South, Elkhart, IN 46517; Mr. John Kime Century Motor Coach 59140 County Road 3 South Elkhart IN 46517; Dear Mr. Kime: This is to follow-up on your phone conversation of September 15, 1981 with Stephen Oesch of my staff concerning the agency's certification requirements for persons who alter certified vehicles. Your specific question was whether an alterer has to certify that the vehicle, as altered, is in compliance with all applicable safety standards affected by the alterations as of the date of the completion of the alterations or as of the date of the manufacture of the original vehicle. As explained below, an alterer may, at his or her option, choose either date.; The agency's certification regulations are set forth in Part 567 *Certification* (49 CFR Part 567), a copy of which is enclosed. Section 567.7 of the regulation applies to persons who alter certified vehicles. Section 567.7 specifies the content of the certification statement that must be affixed to the vehicle by the alterer. The portion of the regulation pertinent to your question is section 567.7(a) which provides that the alterer must state:; >>>'This vehicle was altered by (individual or corporate name) i (month and year in which alterations were completed) and as altered it conforms to all applicable Federal Motor Vehicle Safety Standards affected by the alterations and in effect in (month, year).' The second date shall be no earlier than the manufacturing date of the original vehicle, and no later than the date alterations were completed....<<<; Thus, the regulation allows an alterer the option of choosing eithe the date of original manufacture or the date of completion of the alterations as the date for determining which safety standards apply.; As you requested, I have also enclosed a copy of Standard No. 208 *Occupant Crash Protection*. Section 4.2.2 specifies the requirements applicable to trucks and multipurpose passenger vehicles with a gross vehicle weight rating of 10,000 pounds or less manufactured on or after January 1, 1976.; If you have any further questions, please let me know. Sincerely, Frank Berndt, Chief Counsel |
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ID: aiam3475OpenMr. John Kime, Century Motor Coach, 59140 County Road 3 South, Elkhart, IN 46517; Mr. John Kime Century Motor Coach 59140 County Road 3 South Elkhart IN 46517; Dear Mr. Kime: This is to follow-up on your phone conversation of September 15, 1981 with Stephen Oesch of my staff concerning the agency's certification requirements for persons who alter certified vehicles. Your specific question was whether an alterer has to certify that the vehicle, as altered, is in compliance with all applicable safety standards affected by the alterations as of the date of the completion of the alterations or as of the date of the manufacture of the original vehicle. As explained below, an alterer may, at his or her option, choose either date.; The agency's certification regulations are set forth in Part 567 *Certification* (49 CFR Part 567), a copy of which is enclosed. Section 567.7 of the regulation applies to persons who alter certified vehicles. Section 567.7 specifies the content of the certification statement that must be affixed to the vehicle by the alterer. The portion of the regulation pertinent to your question is section 567.7(a) which provides that the alterer must state:; >>>'This vehicle was altered by (individual or corporate name) i (month and year in which alterations were completed) and as altered it conforms to all applicable Federal Motor Vehicle Safety Standards affected by the alterations and in effect in (month, year).' The second date shall be no earlier than the manufacturing date of the original vehicle, and no later than the date alterations were completed....<<<; Thus, the regulation allows an alterer the option of choosing eithe the date of original manufacture or the date of completion of the alterations as the date for determining which safety standards apply.; As you requested, I have also enclosed a copy of Standard No. 208 *Occupant Crash Protection*. Section 4.2.2 specifies the requirements applicable to trucks and multipurpose passenger vehicles with a gross vehicle weight rating of 10,000 pounds or less manufactured on or after January 1, 1976.; If you have any further questions, please let me know. Sincerely, Frank Berndt, Chief Counsel |
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ID: aiam3607OpenMr. Donald J. Cameron, Director - Technical Support, New York City Transit Authority, 25 Jamaica Avenue, Brooklyn, NY 11207; Mr. Donald J. Cameron Director - Technical Support New York City Transit Authority 25 Jamaica Avenue Brooklyn NY 11207; Dear Mr. Cameron: This responds to your recent letter asking whether the driver's sid window and the front entrance door window of a bus may be equipped with plastic glazing. You desire to use plastics because of the high operating cost of replacing broken glass windows.; The answer to your question is no. Safety Standard No. 205, *Glazin Materials*, was amended in 1977 to permit the use of rigid plastic glazing in all doors and windows of buses, *except* windshields or windows to the immediate right or left of the driver (42 FR 61465). The reason for this exception is that windows to the immediate right and left of the driver are necessary for driving visibility and typical plastic material used alone is not sufficiently resistant to abrasion. Plastic glazing would not be allowed in a bus entrance door since this would constitute a window to the immediate right' of the driver. Plastic glazing would be allowed in the rear emergency door, however, if that door was not necessary for driving visibility.; You also ask whether material other than safety glass may be used i either of these locations. I am not sure that I correctly understand your question. If by other materials' you mean, for example, sheet metal, the answer to your question would be yes. There are no Federal requirements specifying that a vehicle have windows in a certain location. Thus, theoretically, there would be nothing to preclude the installation of a solid metal entrance door in a bus. (Obviously, no manufacturer would likely do this because it would compromise driver vision.) If, however, there is a window and it is equipped with traditional glazing materials, the glazing must be in compliance with the performance and location requirements of Standard No. 205. If I have misunderstood your last question, please contact Hugh Oates of my staff and he will clarify the requirements for you (202- 426-2992).; Sincerely, Frank Berndt, Chief Counsel |
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ID: aiam2115OpenMr. William F. Morie, Executive Vice President, Georgia Automobile Dealers Association, 508 Hartford Building, 100 Edgewood Avenue, N.E., Atlanta, GA 30303; Mr. William F. Morie Executive Vice President Georgia Automobile Dealers Association 508 Hartford Building 100 Edgewood Avenue N.E. Atlanta GA 30303; Dear Mr. Morie: This is in response to your letter of September 19, 1975, inquiring a to the disclosure responsibilities of an individual who sells a vehicle with nonoperational odometer.; You describe a situation in which a dealer executed an odomete disclosure statement indicating that the actual odometer mileage was unknown where the odometer was nonfunctional. Apparently, the purchaser now claims sale of the vehicle with such an odometer inaccuracy constitutes misrepresentation by the dealer.; Based upon the facts of the case as you have presented them, th National Highway Traffic Safety Administration (NHTSA) does not consider that a violation of the odometer requirements of the Motor Vehicle Information and Cost Savings Act (Pub. L. 92-513) has occurred. If the dealer in question executed an odometer disclosure statement, at the time of sale, that complies with the Federal disclosure requirements (49 CFR Part 580, *Odometer Disclosure Requirements), and states that the mileage indicated on the odometer differs from the true mileage for reasons other than calibration error he satisfied his responsibilities under the law. The buyer was informed that the odometer mileage was incorrect and therefore should not be relied upon as an indication of the vehicle's condition.; As long as a seller informs his buyer as to the validity of th odometer mileage, he has no additional responsibility to repair an apparently nonfunctional odometer.; Sincerely, Frank Berndt, Acting Chief Counsel |
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ID: aiam3147OpenMr. Sonny Raidt, Performance Plus Products, Ltd., P.O. Box 5636, Greenville, MS 38701; Mr. Sonny Raidt Performance Plus Products Ltd. P.O. Box 5636 Greenville MS 38701; Dear Mr. Raidt: This is in response to the questions that you raised on October 23 1979, with Ms. Debra Weiner of my office concerning the legal and technical issues arising from the manufacture of auxiliary fuel tanks for use in pickup trucks. You noted that you are going into the business of manufacturing auxiliary fuel tanks, that you will not be involved in the installation of such tanks, and that you would like any advice that we might be able to provide as to the construction standards that should be followed in manufacturing such tanks.; I have enclosed a copy of a letter which was sent to a company tha planned to manufacture auxiliary fuel tanks for passenger cars and to do some installation. The legal principles enunciated in that letter are applicable to auxiliary fuel tanks intended for use in all types of motor vehicles except motor carriers in interstate commerce. Although your company is not planning to install auxiliary tanks, I think that you might find that the discussion of the legal issues that arise with respect to installation may be helpful in determining what safety margins should be built into these types of tanks.; As Ms. Weiner noted on the phone, this agency has not issued an standards applicable to the construction of auxiliary fuel tanks. However, the Federal Highway Administration, Bureau of Motor Carrier Safety has issued standards relevant to the construction of auxiliary fuel tanks for use in motor vehicles which are engaged in interstate commerce. I have enclosed a copy of these standards in hope that they will provide you with some suggestions as to what would constitute safe construction of an auxiliary fuel tank. In addition, the Society of Automotive Engineers has published standards pertinent to some aspects of the construction of fuel tanks. I have also enclosed copies of these.; I hope that you will find the enclosed material helpful. If you hav any further questions, please feel free to contact Ms. Weiner for further information.; Sincerely, Frank Berndt, 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.