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 |
|---|---|
ID: aiam3094OpenMr. R. M. Premo, Director, Vehicle Safety Activities, Sheller-Globe Corporation, 3555 St. Johns Road, Lima, OH 45804; Mr. R. M. Premo Director Vehicle Safety Activities Sheller-Globe Corporation 3555 St. Johns Road Lima OH 45804; Dear Mr. Premo: This responds to your August 27, 1979, letter asking how the agenc tests a floor joint for compliance with Standard No. 221, *School Bus Body Joint Strength*. You enclosed a sketch and sample floor joint with your letter and asked in which direction the forces would be applied for test purposes. You suggested that the forces be applied in a perpendicular direction to the floor.; The floor joint that you manufacture is welded in three locations. On weld is located on top of the floor surface and joins the two panels together. The agency concludes that this joint should be tested by applying force in a direction that is parallel to the floor surface, not perpendicular to it. This is the procedure that is specified in section S6 of the standard for testing joints that are constructed in a manner similar to the floor joint in your vehicle.; Sincerely, Frank Berndt, Chief Counsel |
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ID: aiam2996OpenMr. Paul Utans, Product Compliance, Subaru of America, Inc., 7040 Central Highway, Pennsauken, NJ 08109; Mr. Paul Utans Product Compliance Subaru of America Inc. 7040 Central Highway Pennsauken NJ 08109; Dear Mr. Utans:#This is in response to your letter of March 26, 1979 requesting our interpretation of whether the turn signal identification symbol which you propose meets the requirements of Federal Motor Vehicle Safety Standard No. 101-80, *Controls and Displays*. The answer is yes. As long as the turn signal symbol is displayed in the horizontal mode, as shown in Table 1, it will comply with the standard. Small additional arrows that will not be confused with the turn signal symbol may be incorporated to indicate movement of the control. Your thin vertical arrows do not appear to pose any possibility of causing such confusion.#Sincerely, Frank Berndt, Acting Chief Counsel; |
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ID: aiam2997OpenMr. Paul Utans, Product Compliance, Subaru of America, Inc., 7040 Central Highway, Pennsauken, NJ 08109; Mr. Paul Utans Product Compliance Subaru of America Inc. 7040 Central Highway Pennsauken NJ 08109; Dear Mr. Utans:#This is in response to your letter of March 26, 1979 requesting our interpretation of whether the turn signal identification symbol which you propose meets the requirements of Federal Motor Vehicle Safety Standard No. 101-80, *Controls and Displays*. The answer is yes. As long as the turn signal symbol is displayed in the horizontal mode, as shown in Table 1, it will comply with the standard. Small additional arrows that will not be confused with the turn signal symbol may be incorporated to indicate movement of the control. Your thin vertical arrows do not appear to pose any possibility of causing such confusion.#Sincerely, Frank Berndt, Acting Chief Counsel; |
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ID: aiam1400OpenMr. Paul J. Kruder, President, CIMS COS., P.O. Box 1610, Akron, Ohio 44309; Mr. Paul J. Kruder President CIMS COS. P.O. Box 1610 Akron Ohio 44309; Dear Mr. Kruder: This is in reply to your letter of January 15, 1974, requestin information on the labeling requirements of Motor Vehicle Safety Standard No. 117. The agency has recently amended Standard No. 117 in accordance with the Court of Appeals decision in *National Tire Dealers' and Retreaders' Association v. Brinegar*. The standard as amended requires only that retreaded tires be permanently labeled with maximum load. All the other information required -- size, tubeless or tube-type, maximum inflation pressure, and radial and bias/belted designation -- may appear on affixed labels. The amendment does allow the use of one permanent label to apply all of the required information.; Yours truly, Richard B. Dyson, Assistant Chief Counsel |
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ID: aiam1941OpenMr. Donald W. Taylor, Manager, Product Safety & Quality, Volvo of America Corporation, Rockleigh, NJ 07647; Mr. Donald W. Taylor Manager Product Safety & Quality Volvo of America Corporation Rockleigh NJ 07647; Dear Mr. Taylor: This responds to Volvo of America Corporation's May 9, 1975, reques for reconsideration of the NHTSA's March 31, 1975, determination that a Volvo brake system that employs air pressure modulated by the vehicle operator to provide the energy used to actuate the brakes is an air brake system subject to Standard No. 121, *Air brake systems*.; Having reviewed all of the data submitted with your letter, it i concluded that the Volvo system is an air brake system subject to Standard No. 121. In the development of separate air brake and hydraulic brake system standards, the NHTSA had to make a determination of the status of brake systems which employ both air and hydraulic fluid as a means of transmitting force to the vehicle brakes. The agency decided that use of air as a means of power and transmission of the brake force would qualify the system as an air brake system. This decision permits manufacturers to determine with certainty whether a standard applies to their products.; Since the withdrawal of applicability to trucks of Standard No. 105-75 *Hydraulic brake systems*, our decision has had the beneficial effect of ensuring that 'air over hydraulic' systems are subject to a braking standard. If you are aware of any adverse safety consequences of our decision, I would appreciate hearing from you.; Sincerely, Robert L. Carter, Associate Administrator, Motor Vehicl Programs; |
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ID: aiam2695OpenHonorable Charles Wilson, House of Representatives, Washington, DC 20515; Honorable Charles Wilson House of Representatives Washington DC 20515; Dear Mr. Wilson: This responds to your October 19, 1977, letter enclosing correspondenc from your constituent, Mr. M. M. Davis, concerning the remanufacture of school buses.; The manufacture that Mr. Davis proposes to undertake would mount an ol school bus body on a new school bus chassis. The regulations of the National Highway Traffic Safety Administration that Mr. Davis enclosed in his letter explicitly state that the use of a new chassis in the remanufacture of a motor vehicle results in the manufacture of a new motor vehicle. Such motor vehicle would be required to comply with all safety standards in effect on the date of manufacture of the chassis or final manufacture of the vehicle or any time between those two dates. In the case of a remanufactured school bus using a chassis manufactured after April 1, 1977, the bus would be required to comply with all of the Congressionally mandated school bus regulations that became effective on April 1.; Sincerely, Joan Claybrook |
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ID: aiam2214OpenMr. Joseph S. Russo, 693 Central Avenue, Jefferson Parish, Jefferson, LA 70121; Mr. Joseph S. Russo 693 Central Avenue Jefferson Parish Jefferson LA 70121; Dear Mr. Russo: This is in response to your letter of January 29, 1976, requesting a opinion as to whether documents enclosed with your correspondence would satisfy the requirements of the disclosure provisions contained in Section 408 of the Motor Vehicle Information and Cost Savings Act (Pub. L. 92-513) and 49 CFR Part 580.; It appears that both documents contain all of the information necessar to comply with the odometer disclosure requirements.; Sincerely, John Womack, Assistant Chief Counsel |
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ID: aiam0453OpenMr. David A. Phelps, Jr., Group Supervisor, Engineering Services, Blue Bird Body Company, Fort Valley, GA 31030; Mr. David A. Phelps Jr. Group Supervisor Engineering Services Blue Bird Body Company Fort Valley GA 31030; Dear Mr. Phelps: In your letter of October 4, 1971, you asked whether under ou Certification regulations (49 CFR Part 567) tandem axles should be considered as a unit in listing the gross axle weight rating, or should be listed separately with separate ratings.; We intend that each axle, including those part of a tandem arrangement should be listed separately with a GAWR for each.; Sincerely, Lawrence R. Schneider, Chief Counsel |
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ID: aiam2646OpenMr. James R. Green, 3396 Alma Street, Lynwood, CA 90262; Mr. James R. Green 3396 Alma Street Lynwood CA 90262; Dear Mr. Green: In his letter of June 16, 1977, our Mr. Driver, Director of the Offic of Crash Avoidance, commented that although the Federal motor vehicle lighting standard 'is generally in accordance with standards developed and published by the Society of Automotive Engineers, it does not specifically require sealed-beam headlamps.'; This should not be interpreted as an opinion that Federal Motor Vehicl Safety Standard No. 108 does not require sealed beam headlamps. While there is no such requirement *per se* in the text of the standard, Standard No. 108 incorporates by reference SAE Standard J579a *Sealed Beam Headlamp Units for Motor Vehicles*, August 1965, and SAE Standard J580a *Sealed Beam Headlamp*, June 1966. Compliance of headlamps with these standards is required, whether as original or replacement equipment.; |
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ID: aiam3401OpenMr. John G. Frail, P.O. Box 581, Bronxville, NY 10708; Mr. John G. Frail P.O. Box 581 Bronxville NY 10708; Dear Mr. Frail: This is in reply to your letter of April 9, 1981, to this agenc asking, with respect to Motor Vehicle Safety Standard No. 108, 'whether the minimum edge to edge separation distance between lamp and tail or stop lamp of 4 inches is measured *outside* of the lamp or *inside of the lamp*.' You have asked this question in behalf of an 'OEM supplier' in Germany.; The requirement in Table IV of Standard No. 108 is that the minimu edge to edge separation distance between a turn signal lamp and a tail or stop lamp be 4 inches while the turn signal lamps themselves must have a minimum separation distance of 9 inches between their centerlines. (Your design is somewhat confusing as it depicts centerlines of stop lamps and turn signal lamps at 9 inches.) We interpret this as meaning the minimum separation distance between the edge of lighted area to be 4 inches, as depicted in 'B' in your design. Of course, final responsibility for compliance with this requirement rests on the vehicle manufacturer rather than the equipment manufacturer.; 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.