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: aiam0244OpenLouis C. Lundstrom, Director, Automotive Safety Engineering, General Motors Corporation, General Motors Technical Center, Warren, MI 48090; Louis C. Lundstrom Director Automotive Safety Engineering General Motors Corporation General Motors Technical Center Warren MI 48090; Dear Mr. Lundstrom: This is in reply to your letter of June 26, 1970, to Mr. Douglas W Toms, Director, National Highway Safety Bureau, concerning plastic materials for reflex reflectors.; The contents of your letter, including the technical data an information enclosed therewith, have been carefully reviewed by interested members of this Bureau. As a result of this review and evaluation, and also considering the nature and intent of the requirements in question, we concur, basically, with your interpretation of the requirements of SAE J576b, as subreferenced in Federal Motor Vehicle Safety Standard No. 108. Your interpretation of the requirements of paragraphs 3.4 and 4.2 of SAE J576b, as quoted from your letter, is as follows:; >>>'A plastic material used in a lamp or reflector assembly so that i is covered by other material and is not directly exposed to sunlight meets the requirements of SAE J576b if, when so covered, it satisfies the requirements of paragraphs 3.4 and 4.2.'<<<; We would fully concur with this interpretation if it is rephrased t read as follows:; >>>'A plastic material used in a lamp or reflector assembly so that i is covered by other material and is not directly exposed to sunlight meets the requirements of paragraphs 3.4 and 4.2 of SAE J576b if, when so covered, it satisfies the requirements of those paragraphs.'<<<; To test for compliance, using this interpretation, the test sampl discs, as specified in SAE 576b, would be exposed to the outdoor exposure test (paragraph 3.4) while covered with the actual lens material used in production lamp assemblies. In your particular case, the discs would be the polycarbonate ('Lexan') material and the 'covering material' would be the red taillamp lens molded for production use.; Sincerely, Rodolfo A. Diaz, Acting Associate Director, Motor Vehicl Programs; |
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ID: aiam1707OpenMr. Norman E. Salzman, General Manager, The Fairmount Press, P.O. Box 3, Bronx, NY 10453; Mr. Norman E. Salzman General Manager The Fairmount Press P.O. Box 3 Bronx NY 10453; Dear Mr. Salzman: This is in response to your letter of November 18, 1974, enclosin amended copies of your MVF disclosure form for our review.; The disclosure forms contained in your letter fail to conform to Par 580, *Odometer disclosure requirements*, in two of the aspects described in our letter to you of September 27, 1974. 49 CFR Part 580.4(a) specifies that the transferor of a motor vehicle must furnish his transferee with a written odometer disclosure statement 'before issuing any transfer of ownership document.' Subparagraph (1) of that subsection requires that the disclosure statement include the 'odometer reading at the time of transfer.' The mileage disclosure section of your form is phrased so as to suggest that the odometer mileage was disclosed *after* the completion of transfer. This is contrary to the regulation's provisions and should be corrected to clearly express that the mileage is being disclosed at the time of the vehicle's transfer. Insertion of the word 'is' instead of 'was ' just prior to the odometer mileage disclosure will bring your form into conformity with the regulation.; The requirement in section 580.4(3) of the regulation provides that th transferor make an odometer disclosure by executing 'the disclosure form specified'. While we have not gone so far as to interpret this to require a verbatim copy of our format, we do insist that any variations do not change the significance of the specified formula. In our form, the use of the words 'I, *(transferor's name) state that . . .' is intended to make it clear that the factual representations of the form are those of the transferor. Any formula that fails to accomplish this will not be considered in conformity with the regulation.; I have enclosed a corrected copy of your disclosure form in order t make clear the changes necessary for compliance.; Yours truly, Richard B. Dyson, Acting Chief Counsel |
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ID: aiam0383OpenMr. Charles J. Calvin, Managing Director, Truck Trailer Manufacturers Association, 1413 K Street, NW., Washington, DC, 20005; Mr. Charles J. Calvin Managing Director Truck Trailer Manufacturers Association 1413 K Street NW. Washington DC 20005; Dear Mr. Calvin: This replies to your letter of June 30, 1971, and has reference t previous discussions your Mr. Gray and Mr. Wilson had with members of my engineering staff concerning lamp and reflector locations for trailers.; We have reviewed the drawings submitted and find that the locations an types of lamps and reflectors to be acceptable under the provisions of the Motor Carrier Safety Regulations. As we noted in past correspondence on this subject, a license plate light is not required by our present regulations. Again, the impression should not be given that this lamp, if not required by State regulation, must be installed on vehicles not certified to comply with Motor Vehicle Safety Standard No. 108.; The Bureau of Motor Carrier Safety appreciates the efforts of you association in aiding motor carriers to understand and comply with the Motor Carrier Safety Regulations.; Sincerely yours,Robert A. Kaye, Director |
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ID: aiam1411OpenMr. A. M. Fischer, Engineering Division, Mack Trucks, Inc., P. O. Box 1761, Allentown, PA, 18105; Mr. A. M. Fischer Engineering Division Mack Trucks Inc. P. O. Box 1761 Allentown PA 18105; Dear Mr. Fischer: This is in reply to your letter of February 4, 1974, concerning th location requirements of front identification lamps on certain solid-waste disposal vehicles.; You describe the vehicles in question as 'short BBC low cab-over-engin type vehicles -- equipped with a large volume body and a hydraulically operated front loader mechanism. This unit lifts containers of waste up and over the front of the cab and empties the waste into the top of the body. To prevent damage to the front of the vehicle and lamps, a protective guard is installed on the front centerline of the vehicle.' You further state that 'This guard could obstruct the center identification lamp.'; You ask whether or not all three of the front identification lamps ma be offset from the front centerline of the vehicle to ensure compliance with the visibility requirements of FMVSS No. 108. In accordance with paragraph S4.3.1, Table II of FMVSS No. 108 specifies that the front identification lamps be located 'as close as practicable to the top of the vehicle, at the same height, as close as practicable to the vertical centerline.' For the vehicles which you have described, it would appear that location of the front identification lamps either left or right of the vertical centerline would meet this requirement.; Sincerely, E. T. Driver, Director, Office of Operating Systems, Moto Vehicle Programs; |
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ID: aiam2820OpenMr. Wayne C. Parsil, Minnesota Claims Services, 402 South Cedar Lake Road, Minneapolis, Minnesota 55405; Mr. Wayne C. Parsil Minnesota Claims Services 402 South Cedar Lake Road Minneapolis Minnesota 55405; Dear Mr. Parsil: This responds to your inquiry concerning the steering wheel system on 1972 Plymouth Cricket. You ask whether Federal safety standards permitted non-collapsible steering columns on that vehicle model, whether the steering columns met all safety standards, and whether the vehicle manufacturer was exempted from Federal safety standards on the 1972 Plymouth Cricket because of hardship.; Federal Motor Vehicle SAfety Standard No. 203, *Impact Protection fo the Driver from the Steering Control System* (49 CFR 571.203), became effective for all passenger cars manufactured on or after January 1, 1968. Therefore, a 1972 Plymouth Cricket had to meet the performance requirements specified in that standard. I am enclosing a copy of Standard No. 203 for your information, and you should note that the standard does not specifically require 'collapsible steering columns. Rather, the standard limits the force loads that can be imparted by the steering column during a dynamic impact test.; Under Federal motor vehicle safety regulations, manufacturers ar required to determine for themselves that their vehicles are in compliance and to certify the vehicles as being in compliance. The National Highway Traffic Safety Administration only conducts compliance tests on a 'spot-check' basis for purposes of enforcement. Therefore, I cannot tell you whether the particular Plymouth with which you are interested was in fact in compliance with all safety standards. I can tell you that the agency has not made any determinations that the 1972 Plymouth Crickets failed to comply with Safety Standard No. 203.; Regarding your final question, no exemption from Standard No. 203 wa granted for the 1972 Plymouth Cricket.; please contact this office if you have any further questions. Sincerely, Joseph J. Levin, Jr., Chief Counsel |
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ID: aiam3394OpenMr. M. Iwase, Manager, Technical Administration Dept., Koito Manufacturing Co., Ltd., Shizuoka Works, 550, Kitawaki, Shimizu- Shi, Shizuika-Ken, Japan; Mr. M. Iwase Manager Technical Administration Dept. Koito Manufacturing Co. Ltd. Shizuoka Works 550 Kitawaki Shimizu- Shi Shizuika-Ken Japan; Dear Mr. Iwase: This is in reply to your letter of February 12, 1981, asking whethe the placement of a clear lens cover in front of a motorcycle headlamp would be permissible under Federal Motor Vehicle Safety Standard No. 108.; SAE Standard J580 (both a and b versions) *Sealed Beam Headlam Assembly* is incorporated by reference in Tables I and III of the standard as one of the standards pertaining to headlamps for use on passenger cars, trucks, buses, and multipurpose passenger vehicles. Paragraph 5.2 of J580 states that, 'When in use, a headlamp shall not have any styling ornament or other feature, such as a glass cover or grill, in front of the lens.'; The principal referenced SAE material for motorcycle headlamps is J584 *Motorcycle Headlamps*. As options, both J584 and S4.1.1.34 of Standard No. 108 allow, in effect, a motorcycle to be equipped with one half of any sealed beam system permissible on four-wheeled motor vehicles. We therefore view the prohibition of J580 as applicable to use of any sealed beam headlamp, regardless of the type of vehicle on which it is installed.; Paragraph S4.1.3 of Standard No. 108 forbids the installation o additional equipment 'that impairs the effectiveness of lighting equipment required' by Standard No. 108. Because of moisture accumulation, discoloration, cracks, etc., a glass or plastic cover might tend over a period of time to diminish or distort the headlamp beam. This is of particular concern with reference to the unsealed headlamps implicitly permitted by SAE J584 because of the tendency of the reflector to deteriorate with age.; The agency therefore has concluded that no motorcycle headlamp may hav a glass shield in front of it when in use.; Sincerely, Frank Berndt, Chief Counsel |
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ID: aiam2571OpenMr. Jim Beach, Collins Industries, Inc., Box 58, Hutchinson, KS 67501; Mr. Jim Beach Collins Industries Inc. Box 58 Hutchinson KS 67501; Dear Mr. Beach: This confirms your April 19, 1977, conversation with Roger Tilton of m staff concerning the definition of school bus.; The National Highway Traffic Safety Administration (NHTSA) define school bus in a notice issued on December 31, 1975 (40 FR 60033) to mean 'a bus that is sold, or introduced into interstate commerce, for purposes that include carrying students to and from school or related events, but does not include a bus designed and sold for operation as a common carrier in urban transportation.' This definition incorporates by reference the definition of bus (49 CFR Part 571.3) which is 'a motor vehicle with motive power, except a trailer, designed for carrying more than 10 persons.' Therefore, by definition a school bus is a vehicle that carries more than 10 persons (e.g., 10 passengers and a driver). This does not preclude smaller vehicles from transporting school children. Vehicles carrying 10 or fewer persons would not have to comply with the school bus construction requirements.; I am enclosing a copy of the notice that established the school bu definition. If you have further questions, do not hesitate to contact us.; Sincerely, Frank Berndt, Acting Chief Counsel |
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ID: aiam0149OpenMr. E.E. Wolfe, Controller, Carlisle Tire & Rubber Company, Carlisle Corporation, Carlisle, Pennsylvania 17013; Mr. E.E. Wolfe Controller Carlisle Tire & Rubber Company Carlisle Corporation Carlisle Pennsylvania 17013; Dear Mr. Wolfe: Your December 27, 1968, request for a code number i accordance with subsection S4.3 of the Federal Motor Vehicle Safety Standard No. 109 and the national Traffic and Motor Vehicle Safety Act of 1966 (15 U.S.C. 1421(1)) has been reviewed. Subsection S4.3 of the Federal Motor Vehicle Safety Standard No. 109 applies to passenger car tires, accordingly, the National Highway Safety Bureau has restricted the issuance of code numbers to manufacturers of these tires.; Since Carlisle Tire and Rubber Division does not engage in th manufacture of passenger car tires, and since the code number was requested in anticipation of future tire rule making, the issuance of a code number to the Carlisle Tire and Rubber Division would be premature and not in keeping with the intent of the regulations.; We have enclosed a Mailing List Questionnaire as promised. To assure flow of specialized mailings which may be of great importance to your particular organisation, please complete both sides with the correct information and return it to the Federal Highway Administration, National Highway Safety Bureau, Motor Vehicle Safety Performing Service, Washington, D.C. 20591. *Attention:* MVSPS Mailing List Questionnaire. If you require more than one form or have any inquiries concerning the form, Please direct your correspondence to the same address.; Sincerely, Roger H. Compton, Director, Office of Standard on Acciden Avoidance, Motor Vehicle Safety Performance Service; |
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ID: aiam2346OpenHonorable Bob Sikes, House of Representatives, Washington, DC 20515; Honorable Bob Sikes House of Representatives Washington DC 20515; Dear Mr. Sikes:#This is in response to your May 10, 1976, communicatio enclosing a letter from Mr. John C. Richardson concerning the importation of passenger cars with 'metric instrumentation.' Your communication was forwarded to this agency by the National Bureau of Standards for reply.#Mr. Richardson has encountered difficulty in importing a 1976 model 911 Porsche with metric instrumentation. He has received a letter from Volkswagen of America, Inc., suggesting that 'such instrumentation would be illegal and not certified with the appropriate U.S. Government agencies.' While the precise meaning of 'metric instrumentation' is not clear from either letter, I assume that Mr. Richardson is referring to the marking of the speedometer (in kilometers per hour) and the calibration of the odometer (in kilometers traveled).#The Federal motor vehicle safety standards administered by the National Highway Traffic Safety Administration do not presently require any particular form of marking for speedometers or odometers. While we are considering the establishment of a requirement that English units be used, such a rule would permit metric units as an optional addition. Furthermore, such a rule would only be applied prospectively.#Sincerely, Frank A. Berndt, Acting Chief Counsel; |
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ID: aiam2073OpenMr. Naoyoshi Suzuki, Nissan Motor Co., Ltd. 560 Sylvan Avenue, Englewood Cliffs, NJ 07632; Mr. Naoyoshi Suzuki Nissan Motor Co. Ltd. 560 Sylvan Avenue Englewood Cliffs NJ 07632; Dear Mr. Suzuki:#This is in response to your September 16, 1975, lette to Mr. John Carson of this agency, concerning Federal Motor Vehicle Safety Standard No. 101, *Control Location, Identification and Illumination*. You requested an interpretation of the footnote to Table 1 of the standard which reads: 'Framed areas may be filled'.#The National Highway Traffic Safety Administration interprets this footnote as permitting the vehicle manufacturer the option of depicting the interior of a symbol to which it applies with the same color as the boundary of the symbol, as an alternative to depicting the interior with the same color as the background. In the hazard warning signal symbol, which consists of a triangle containing a smaller triangle, only the area between the triangles is part of the interior. The center of the small triangle is part of the background. Therefore, only the first and third of the samples submitted with your letter are permitted. For your convenience, I have enclosed a copy of the samples indicating which ones are permitted.#Sincerely, Frank A. Berndt, 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.