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: aiam4526OpenMr. Paul Scully Vice President Peterson Manufacturing Co. 4200 East 135th St. Grandview, MO 64030; Mr. Paul Scully Vice President Peterson Manufacturing Co. 4200 East 135th St. Grandview MO 64030; Dear Mr. Scully: This is in reply to your letter of April 22, l988 asking for a clarification of a letter that this Office sent Wesbar Corporation on March 16, 1988, with respect to the term 'effective projected luminous area.' Wesbar had asked whether it could include the 'illuminated (by the turn signal bulb) reflex reflector portion of the turn signal lens' (Wesbar's language) in its calculation of the l2 square inch minimum effective projected luminous area required by S4.1.1.7 of Safety Standard No. 108. We replied that it could, assuming that the light shines through the reflector. You have pointed out that although a small amount of light escapes through a reflex reflector, the reflector is designed to return light from an outside source, rather than to direct light from a source inside the lamp, and that heretofore agency interpretations (e.g. on October 28, 1970, and October 28, 1979) had expressly excluded reflex reflectors from areas included in the calculation of effective projected luminous area. Reflex reflectors are also excluded from the term by SAE J387 Terminology. We appreciate your calling this matter to our attention. Previous interpretations by this Office clearly indicate that a 'reflex reflector' is not to be included in the calculation of effective projected luminous area. We also note that the SAE definition (paragraph 2, SAE J594f, January l977) is incorporated by reference into Standard No. 108, stating that this item of equipment is one that provides an indication of vehicle presence by reflected light (rather than projected light). We are providing a copy of this letter to Wesbar so that it will be apprised of our reevaluation, and our conclusion that the reflex reflector portion of a lens cannot be included in the calculations of the projected luminous lens area. I hope this clarifies the matter for you. Sincerely, Erika Z. Jones Chief Counsel; |
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ID: aiam0565OpenMr. E. R. Sternberg, Director, Engineering Planning - Truck Group, White Motor Corporation, 100 Brieview Plaza, Cleveland, OH 44144; Mr. E. R. Sternberg Director Engineering Planning - Truck Group White Motor Corporation 100 Brieview Plaza Cleveland OH 44144; Dear Mr. Sternberg:#This is in reply to your letter of January 3, 1972 requesting an interpretation of S4.2.2 of Standard No. 101, as it applies to your proposed method of compliance for push-pull controls.#S4.2.2 requires, in pertinent part, that 'Identification shall be provided for each function of any . . . heating and air conditioning system control, and for the extreme positions of any such control that regulates a function over a quantitative range.' Identification such as that shown in your Example (2) would meet Standard No. 101, while the identification provided in Example (3) would not. Legends such as 'Pull on' and 'Push off' might more clearly indicate control positions than your suggested 'Max (out)' and 'Off (in).' The control which operates both the defroster and heater must identify both functions, 'Defrost' as indicated is insufficient. Legends such as 'Pull to defrost' and 'Push for heat' would be acceptable for conformance.#Sincerely, Richard B. Dyson, Assistant Chief Counsel; |
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ID: aiam2558OpenMr. L. Wenderoth, Bandag of Nassau, Inc., 40 Brook Avenue, Deer Park, New York 11729; Mr. L. Wenderoth Bandag of Nassau Inc. 40 Brook Avenue Deer Park New York 11729; Dear M. Wenderoth: This responds to your March 10, 1977, letter asking whether it i permissible for you to use a DOT number assigned to another tire retreader when you perform special retread work in your plant for the other retreader who lacks facilities to do the work himself.; Standard No. 117, *Retreaded Pneumatic Tires*, requires that th retreader apply a DOT symbol and identification number to the tire. The DOT symbol indicates conformance with Federal regulations. The number enables the National Highway Traffic Safety Administration (NHTSA) to identify the retreader that manufactures the tire. To permit one manufacturer to use the identification number of another would impair the NHTSA enforcement actions. Accordingly, you would not be permitted to use any DOT number other than your own on tires you retread.; Sincerely, Frank A. Berndt, Acting Chief Counsel |
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ID: aiam4875OpenMr. Chris Lawrence Chang & Lawrence P.O. Box 105-55 Taipei Taiwan R.O.C.; Mr. Chris Lawrence Chang & Lawrence P.O. Box 105-55 Taipei Taiwan R.O.C.; "Dear Mr. Lawrence: This responds to your letter of April 10, 1991 asking for an amplification of my letter of March 21, with reference to the mounting of an electric sign board in the rear window area, or on the rear, of a passenger car. You have asked whether we would 'object to mounting the board in a side window.' Although the only required lighting equipment mounted on the side of vehicles are side marker lamps and reflectors, the most likely place a vehicle will be seen only from the side is when it is crossing an intersection, at a 90-degree angle to the observer. At other times, in the flow of traffic, the side of the vehicle will be viewed obliquely, whether the driver of another vehicle is approaching it from the front or from the rear. Thus, a side mounted electronic sign board may have an even greater potential for impairing the effectiveness of the required front and rear lighting equipment by its potential to distract other drivers from the signals sent by the front and rear lamps when they and the sign board are operated simultaneously. As I explained on March 21, this might also create a partial inoperability of lighting equipment within the meaning of the prohibition discussed in the letter of August 17, l989, that I enclosed. Whether there is an impairment is determined in the first instance by the manufacturer of the vehicle, if it is the installer, or by the dealer, if it performed such work. If a negative determination appears clearly erroneous, NHTSA will inform the manufacturer or dealer responsible for the determination. You have also asked as to other regulatory bodies that need to be consulted before product marketing for a side mounted sign board can begin. This question appears based on the premise that there would be no Federal objection to the side mounted sign. If you choose to sell this device, its use will be subject to the laws of the States in which it is employed. We are unable to advise you on State laws. The American Association of Motor Vehicle Administrators may be able to assist you. The address is 4600 Wilson Boulevard, Arlington, Va. 22203. Sincerely, Paul Jackson Rice Chief Counsel"; |
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ID: aiam0135OpenHonorable John B. Anderson, House of Representatives, Washington, DC 20515; Honorable John B. Anderson House of Representatives Washington DC 20515; Dear Mr. Anderson: Thank you for your January 8 letter concerning comments by Mr. Jackso Decker of the E. D. Pitnyre Company, which was addressed to the National Highway Safety Bureau on December 20, 1968. I regret that Miss Claybrook of my staff was unable to locate Mr. Decker's letter after the call from your office requesting a copy of my response to Mr. Decker.; Mr. Decker's letter consists of comments to the Federal Highwa Administration Dockets on the pending proposed regulations under which information would be supplied by manufacturers to consumers about various safety performance characteristics of motor vehicles. My staff was unaware of this letter because it was addressed to the Docket and was sent by the mail room directly to the legal office which maintains all dockets. The dockets contain much of the source material which serves as the basis for final rule making on proposed standards and regulations.; In addition, letters such as this are seldom answered not only becaus it is not appropriate to debate the substance of pending rulemaking actions, but also because the purpose of such correspondence is to provide information to the Government in the development of rulemaking. It is not treated as routine correspondence with the agency. In addition, the volume of such comments frequently reaches such vast proportions that it would be virtually impossible to answer them. For example, in response to a recent Federal Highway Administration proposed regulation some 4,000 comments were submitted.; Mr. Decker, incidentally, does not indicate he expected a specifi answer to his letter but, rather, in his last paragraph, asks that his views 'be given serious consideration before proceeding with the issuance of part 275 of the Federal Motor Vehicle Safety Standards.'; On December 30, 1968, the Federal Highway Administrator issued a notic extending for 60 days the time for filing comments on a number of the proposed regulations for consumer information. This notice also specified that the proposed regulations would not apply to vehicles produced in two or more stages. I am enclosing a copy of this notice with the appropriate section marked for your information.; I regret that we had to ask you to supply a copy of Mr. Decker' letter, but I trust that the above information resolves the issues he raised.; Sincerely, William Haddon, Jr., M.D., Director |
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ID: aiam2108OpenMr. Claud Riggs, Mountain States Tire Dealers Association, 1230 Pontiac Street, Denver, CO 80220; Mr. Claud Riggs Mountain States Tire Dealers Association 1230 Pontiac Street Denver CO 80220; Dear Mr. Riggs: Please forgive the delay in responding to your letter of May 1, 1975 which included a list of information items you believe are required to appear on retreaded tires pursuant to Federal Motor Vehicle Safety Standard No. 117, *Retreaded Pneumatic Tires*.; With the following qualifications, your list is correct: >>>1. The tire must be labeled with the symbol 'DOT' followed by th letter 'R', and other information required by 49 CFR Part 574.5, *Tire Identification and Recordkeeping*, as a certification that the tire complies with Standard No. 117. This requirement is distinct from and in addition to the requirement that the casing retain the 'DOT' symbol from its original manufacture.; 2. The words 'bias/belted' are not required, because the actual numbe of plies in the sidewall and, if different, in the tread area, are now required to appear.; 3. Tube-type and tubeless tires must be labeled with the specific word 'tube-type' and 'tubeless', respectively.; 4. The items listed in your third group may appear on a paper labe only if that label is not easily removable.<<<; For you convenience, I have enclosed a copy of Standard No. 117. Yours truly, Richard B. Dyson, Assistant Chief Counsel |
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ID: aiam5337OpenThe Honorable Doug Bereuter U.S. House of Representatives Washington, DC 20515-2701; The Honorable Doug Bereuter U.S. House of Representatives Washington DC 20515-2701; Dear Mr. Bereuter: Thank you for your letter concerning a rulemakin related to compressed natural gas (CNG) vehicle fuel systems and fuel containers. You express concern about the time it is taking to complete the rulemaking. I fully understand your concern over this matter and want to assure you that the agency is working diligently to reach a final decision. The supplemental notice of proposed rulemaking we issued in December 1993 was an essential step toward permitting the use of CNG containers that employ new technologies. We have now reviewed the comments received on this notice and are preparing the final rule. As agency representatives explained when they met with you in December 1993, the final rule will be reviewed by the Office of the Secretary and the Office of Management and Budget. I hope this information is helpful and appreciate your patience in this matter. Sincerely, Christopher A. Hart Acting Administrator; |
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ID: aiam4930OpenMs. Sandra Mesh-Witucki McGraw, Borchard & Martin 5200 State Street Saginaw, Michigan 48603; Ms. Sandra Mesh-Witucki McGraw Borchard & Martin 5200 State Street Saginaw Michigan 48603; "Dear Ms. Mesh-Witucki: This responds to your November 1, 1991 lette in which you asked for 'a certified copy of all rules/standards applicable to (a 1987 Chevrolet Cargo Van Conversion) both before and after conversion, and any other information you feel may be of assistance.' Your letter mentioned that you are interested in this information for pending litigation concerning an accident in which this vehicle was involved in which, '(a)llegedly, a rear seat passenger suffered a spinal fracture from the lap belt.' In a phone conversation with Mary Versailles of my staff on November 26, 1991, you verified that you are specifically interested in regulations concerning the type of safety belts this vehicle was required to have. The following discussion should clarify NHTSA regulations regarding safety belts. The safety belt installation requirements for all vehicle types are set forth in Standard No. 208, Occupant Crash Protection (49 CFR 571.208). S4.2.1 of Standard No. 208 gives vehicle manufacturers a choice of three options for providing occupant crash protection in trucks and multipurpose passenger vehicles with a GVWR of 10,000 pounds or less, manufactured on or after January 1, 1976 and before September 1, 1991. Option 1, set forth in S4.1.2.1, requires vehicle manufacturers to provide automatic protection at the front outboard seating positions, lap or lap/shoulder safety belts at all other seating positions, and either meet the lateral crash protection and rollover requirements by means of automatic protection systems or have manual safety belts at the front outboard seating positions such that those positions comply with the occupant protection requirements when occupants are protected by both the safety belts and the automatic protection. Option 2, set forth in S4.1.2.2, requires vehicle manufacturers to provide a lap or lap/shoulder safety belt at every seating position, have automatic protection for the front outboard seats, and have a warning system for the safety belts provided. Option 3, set forth in S4.1.2.3, requires the manufacturer to install lap or lap/shoulder safety belts at every seating position and to have a warning system for those belts. Standard No. 208 and all the rest of NHTSA's safety standards are found in Title 49 of the Code of Federal Regulations (CFR), Part 571. This and all other volumes of the CFR may be purchased by contacting: Superintendent of Documents U.S. Government Printing Office Washington, D.C. 20402 Phone: (202) 783-3238 Because the CFR is published by the Government Printing Office, that office is the only source for certified copies of the regulations. I hope this information is helpful. If you have any more questions about this issue, feel free to contact Mary Versailles at this address or by telephone at (202) 366-2992. Sincerely, Paul Jackson Rice Chief Counsel"; |
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ID: aiam5622OpenMr. Saburo Inui, Vice President Toyota Motor Corporate Services of North America, Inc. 1850 M. Street, NW Washington, DC 20036; Mr. Saburo Inui Vice President Toyota Motor Corporate Services of North America Inc. 1850 M. Street NW Washington DC 20036; Dear Mr. Inui: This responds to Toyota's August 22, 1995, lette regarding the test procedures in this agency's June 7, 1995, amendment to Federal Motor Vehicle Safety Standard No. 114 (60 FR 30006). You were concerned that the test procedure seems to say that the service brake should be applied at two different steps during the test procedure, without specifying when the service brake should be released in between those two steps. You suggested a revised procedure that specifies a step for releasing the service brake, and asked if that procedure conforms with the National Highway Traffic Safety Administration's (NHTSA) test requirement. After reviewing the issues raised by your letter, we have concluded that a technical amendment should be issued to clarify the test procedure. We expect to issue such an amendment shortly. I hope this information is helpful. If you have any further questions about NHTSA's safety standards, please feel free to contact Paul Atelsek of my staff at this address or by telephone at (202) 366-2992. Sincerely, John Womack Acting Chief Counsel; |
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ID: aiam0420OpenMr. Paul Godfrey, Sales Manager, Long Trailer Company, Inc., Route 2, Box 1, Tarboro, NC, 27886; Mr. Paul Godfrey Sales Manager Long Trailer Company Inc. Route 2 Box 1 Tarboro NC 27886; Dear Mr. Godfrey: This is in reply to your letter of July 30, 1971, to Mr. Ed. Leysath o this office concerning the mounting location of side marker and taillights on your boat trailers.; The mounting requirements for lamps and reflectors are specified i Federal Motor Vehicle Safety Standard No. 108 (copy enclosed). It appears as if devices mounted as indicated on your drawing would meet the requirements. If, however, severe problems would be encountered in mounting the devices as indicated or the devices would be subjected to damage during normal use, other mountings may be appropriate and still meet the 'as far apart as practicable' or 'as far to the rear as practicable' requirements.; If water damage is the only problem when lamps and reflectors ar mounted in the indicated positions, special waterproof devices are available and could be used.; Sincerely, E. T. Driver, Director, Office of Operating Systems, Moto Vehicle Programs; |
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.