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: aiam3997OpenMr. Rawleigh G. Decker, 18018 134 Avenue, Sun City West, AZ 85375; Mr. Rawleigh G. Decker 18018 134 Avenue Sun City West AZ 85375; Dear Mr. Decker: Thank you for your letter of July 23, 1985, to Secretary Dole, whic was referred to my office for reply. You expressed concern about conflicting state regulations on motor vehicle window tinting and asked about possible Federal regulations on this subject.; Congressman John McCain of Arizona has also recently written our agenc concerning conflicts in state tinting laws. I am enclosing a copy of the Administrator's letter of July 11, 1985, to Congressman McCain explaining what action the agency is taking on the subject of vehicle window tinting. I have also enclosed a (sic) information sheet which explains the Federal requirements on vehicle window tinting.; I hope this information is of assistance to you. If you have an further questions, please let me know.; Sincerely, Stephen P. Wood, Assistant Chief Counsel for Rulemaking |
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ID: aiam2685OpenMr. Robert P. Ducey, Grand Teton Trading Co., Box 2436, Jackson, WY 83001; Mr. Robert P. Ducey Grand Teton Trading Co. Box 2436 Jackson WY 83001; Dear Mr. Ducey: This responds to your letter of September 12, 1977, requestin information concerning the certification requirements for acrylic glazing to be used in motor vehicles. Specifically, you are interested in the separate certification responsibilities of the company that manufactures the acrylic sheets, the company that cuts and shapes the acrylic, and the company that constructs aluminum frames around the acrylic and sells windows to the customized van market.; Paragraphs S6.1 and S6.3 of Safety Standard No. 205, *Glazin Materials*, specify that prime glazing material manufacturers shall certify each piece of glazing that is for use in motor vehicles in accordance with section 114 of the National Traffic and Motor Vehicle Safety Act (15 U.S.C. 1381, *et seq*.) and with section 6 of the ANS Z26 standard. These requirements would be applicable to the company from which you buy acrylic sheets, since that company would qualify as a prime glazing material manufacturer.; As a manufacturer or distributor who cuts a section of glazing for us in a motor vehicle, your company would be required to certify its product in the same fashion as your supplier (paragraphs S6.4 and S6.5 of Standard No. 205). Please note, however, that under section 6 of ANS Z26 your company is required to mark any section of glazing that it cuts with the same words, designations, characters, and numerals as the piece of glazing from which it was cut. This means that you would stamp your product with markings identical to the certification markings on the acrylic sheets you purchased.; The company that constructs aluminum around the glazing and sell windows to the customized van market would be required to certify its product in accordance with section 114 of the National Traffic and Motor Vehicle Safety Act. Section 114 provides that an item of motor vehicle equipment (including glazing) may be certified by means of a label or tag on the item of equipment or on the outside of a container in which the equipment is delivered. The label or tag must certify that the item of motor vehicle equipment complies with all applicable motor vehicle safety standards, Standard No. 205 in this case.; Please contact this office if you have any further questions. Sincerely, Joseph J. Levin, Jr., Chief Counsel |
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ID: aiam5140OpenMr. Thomas C. Baloga Manager, Safety Engineering Mercedes-Benz of North America, Inc. One Mercedes Drive P.O. Box 350 Montvale, NJ 07450-0350; Mr. Thomas C. Baloga Manager Safety Engineering Mercedes-Benz of North America Inc. One Mercedes Drive P.O. Box 350 Montvale NJ 07450-0350; "Dear Mr. Baloga: This responds to your letter asking whether th National Highway Traffic Safety Administration (NHTSA) will exercise its discretion not to institute enforcement proceedings with respect to a special seat belt installation in a Mercedes-Benz car owned by a man who weighs approximately 500 pounds. You stated that the owner cannot use the driver-side seat belt because of his large body size and that your special order 12-inch longer belt is still too short. You indicated that your factory has supplied a 30-inch longer seat belt, but that the extra-long belt assembly will not comply with the following aspects of Standard No. 209: --the seat belt will not completely roll up into the B-pillar due to excessive webbing on the spool, --the seat belt has not been tested for retraction spring durability and therefore may not pass the retractor cycle test, --no certification label is attached. As you are aware, our agency is authorized to issue Federal motor vehicle safety standards that set performance requirements for new motor vehicles and items of motor vehicle equipment. Manufacturers are required by the National Traffic and Motor Vehicle Safety Act (Safety Act) to certify that their products conform to our safety standards before they can be offered for sale. Manufacturers, distributors, dealers and repair businesses modifying certified vehicles are affected by 108(a)(2)(A) of the Safety Act. It prohibits those businesses from knowingly rendering inoperative any elements of design installed on a vehicle in compliance with a safety standard. In certain limited situations in the past where a vehicle must be modified to accommodate the needs of a person with a particular disability, NHTSA has stated that it would consider certain violations of Safety Act provisions as purely technical ones justified by public need, and that it would not institute enforcement proceedings. This is to advise you that we will take this position for the specific factual situation cited above, as we equate the special needs of a 500 pound individual with the needs associated with a disability. I note that we expect manufacturers to provide complying seat belts that are appropriate for the normal range of occupant sizes, including large persons. Mercedes-Benz appears to do this, as it provides a (presumably complying) special order 12-inch longer belt for large persons. We recognize that a 500 pound individual is outside the normal range of occupant sizes. You stated that requests for extra long seat belts are likely to continue and asked whether Mercedes-Benz needs to advise NHTSA of each and every special installation or whether it is sufficient to keep appropriate records of the VIN. I note that if the agency was presented again with the same factual situation, we would expect to make the same decision. However, we would want to be advised of each such special installation. One of the factors behind our position is the special nature of the factual situation. If Mercedes-Benz wanted to provide extra long seat belts on a routine basis, we would expect it to provide a design that fully complies with Standard No. 209. Sincerely, John Womack Acting Chief Counsel cc: Jerry Sonosky, Esq. Hogan & Hartson"; |
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ID: aiam0342OpenMr. Keitaro Nakajima, General Manager, Toyota Motor Company, Ltd., Factory Representative Office, Lyndhurst Office Park, 1099 Wall Street West, Lyndhurst, NJ 07071; Mr. Keitaro Nakajima General Manager Toyota Motor Company Ltd. Factory Representative Office Lyndhurst Office Park 1099 Wall Street West Lyndhurst NJ 07071; Dear Mr. Nakajima:#This is in reply to your letter of April 1 seeking clarification of paragraph S4.1.2 of Motor Vehicle Safety Standard No. 104.#We confirm your understanding that S4.1.2 excludes any part of wiped areas A, B, and C that lie outside the perimeter line. Change of your driver's seating reference point to meet the proposed requirements of Standard No. 201 does not affect the percentage of area A, assuming no change in the perimeter line.#Sincerely, Lawrence R. Schneider, Acting Chief Counsel; |
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ID: aiam5510OpenMr. Donnell W. Morrison 1005 Drinnon Drive Morristown, TN 37814; Mr. Donnell W. Morrison 1005 Drinnon Drive Morristown TN 37814; Dear Mr. Morrison: We have received your letter of March 14, 1995 an its attached copy of a letter dated February 14. I am sorry to say that your earlier letter never reached us. You asked whether the mounting height requirements for clearance and identification lamps (Table II of Motor Vehicle Safety Standard No. 108) have been amended to allow their mounting in locations other than 'as high as practicable.' The requirements have not changed since you were at DOT. The primary requirement is that identification lamps are to be mounted 'as close to the top of the vehicle as practicable', and that clearance lamps are mounted 'to indicate the overall width of the vehicle . . . as near the top thereof as practicable.' The determination of practicability is initially that of the manufacturer, to be made in its certification that the vehicle meets all applicable Federal motor vehicle safety standards. NHTSA will not question that determination unless it appears clearly erroneous. However, when the rear identification lamps are mounted at the extreme height of the vehicle, paragraph S5.3.1.4 states that the rear clearance lamps need not be located as close as practicable to the top of the vehicle. Further, if it is necessary to indicate the overall width of the vehicle, or for protection from damage during normal operation of the vehicle, clearance lamps may be mounted at a location other than on the front and rear and need not be visible at 45 degrees inboard (paragraph S5.3.1.1.1). Sincerely, Philip R. Recht Chief Counsel; |
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ID: aiam1800OpenMr. Murray Bartlett, B. F. Goodrich Tire Co., 500 South Main Street, Akron, OH 44318; Mr. Murray Bartlett B. F. Goodrich Tire Co. 500 South Main Street Akron OH 44318; Dear Mr. Bartlett: This letter reviews for conformity with statutory requirements a draf defect notification letter received by my office regarding Goodrich's impending notification campaign for tires retreaded by B. F. Goodrich using carcasses branded 'General Belted Jumbo 780.'; As you are aware, defect notifications issued on or after December 26 1974, are required to comply with the requirements in section 153 of the 1974 amendments to the National Traffic and Motor Vehicle Safety Act (Public Law 93-492, 88 Stat. 1470). We have the following changes to recommend in your draft notification.; Section 153(a)(5) requires the notification to specify 'the earlies date . . . on which such defect or failure to comply will be remedied without charge, and in the case of tires, the period during which such defect or failure to comply will be remedied without charge . . .' We believe this requirement should be met by specifying the actual earliest date by which dealers will have necessary replacement parts and instructions, and by informing owners that they have 60 days from that date (or 60 days from the day they receive the notification, whichever is later) to obtain replacement free of charge.; You must also include information that is responsive to sectio 153(a)(6). As the procedures referred to in that section have not been published, it is sufficient if you advise owners that they may write to the Administrator, National Highway Traffic Safety Administration, Washington, D.C. 20590, if they find B. F. Goodrich, its distributors, or dealers, to have failed or to have been unable to perform the replacement satisfactorily.; In other respects we find your letter to conform to the statutor requirements.; Yours truly, James C. Schultz, Acting Chief Counsel |
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ID: aiam0712OpenMr. Clyde Parrott, Design Engineer, Hamilton Cosco, Inc., State Street, Columbus, IN 47201; Mr. Clyde Parrott Design Engineer Hamilton Cosco Inc. State Street Columbus IN 47201; Dear Mr. Parrott: This is in reply to your letter of May 4, 1972, posing certai questions concerning paragraph S4.10 of Motor Vehicle Safety Standard No. 213, 'Child Seating Systems.' You ask 'what criteria are to be used to determine whether an area is a contactable area under S4.10.'; The components that would be considered contactable by the head unde S4.10.1, or by the torso under S4.10.2, are any components which a child within the weight and height range for which the seat is recommended might contact in a 30 m.p.h. barrier crash, as represented by the test procedure specified in S5.1 and S5.2.; You also ask for clarification of the meaning of 'rigid side' as tha phrase is used in S4.10.3. As we indicated to you in our letter of February 23, 1972, manufacturers should rely on generally available definitions of 'rigid' in determining whether or not components are within the term. The reference to 'side' includes components placed both to the right and left, and forward of and behind the child occupant. Consequently, both an arm rest and a head rest (either separate from the back of a child seat or part of a one piece back of a child seat) could fall within the exemption of S4.10.3. The reference to 'back or side' in the proposed amendment to S4.10 published September 23, 1972 (35 F.R. 14786), is intended purely as a clarification of the existing language, the main thrust of the proposed revision would be, as stated in its preamble, to eliminate the exemption in the head- contact area.; With reference to the status of the September 23 proposal, a final rul based on this notice is still under consideration and we cannot presently provide an indication as to when it may become effective.; Yours truly, Richard B. Dyson, Assistant Chief Counsel |
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ID: aiam4751OpenThe Honorable Lawrence J. Smith U. S. House of Representatives Washington, D.C. 20515; The Honorable Lawrence J. Smith U. S. House of Representatives Washington D.C. 20515; "Dear Mr. Smith: I am writing in response to your letter forwardin correspondence from your constituent, Mr. Joel Leitson, with respect to litigation recently brought by the United States against several firms that install plastic film, or 'tint,' on automobile windows. You have asked about the statutory authority under which these suits were brought. Pursuant to section 103 of the National Traffic and Motor Vehicle Safety Act of 1966 ('Safety Act'), 15 U.S.C. 1392, the National Highway Traffic Safety Administration ('NHTSA') has issued safety standards applicable to new motor vehicles and items of motor vehicle equipment. One of the standards that we have issued under this authority is Federal Motor Vehicle Safety Standard No. 205, Glazing Materials (49 CFR 571.205), which applies to all new vehicles and all new glazing materials for use in motor vehicles. Among the requirements set forth in Standard No. 205 are specifications for minimum levels of light transmittance (70 percent light transmittance in areas requisite for driving visibility, which includes all windows in passenger cars). Section 108(a)(i)(A) of the Safety Act, 15 U.S.C. 1397(a)(1)(A), provides that no person may manufacture or sell any vehicle unless it is in conformity with all applicable safety standards. Pursuant to section 108(b)(1) of the Safety Act, 15 U.S.C. 1397(b)(1), this paragraph does not apply after a vehicle is first sold to a consumer. However, both before and after the first sale, section 108(a)(2) of the Safety Act, 15 U.S.C. 1397(a)(2), provides that 'No manufacturer, distributor, dealer, or motor vehicle repair business shall knowingly render inoperative, in whole or part, any device or element of design installed on or in a motor vehicle or item of motor vehicle equipment in compliance with an applicable Federal motor vehicle safety standard . . . .' Thus, by installing tint film on automobiles that reduces the light transmittance of their glass below 70 percent, the firms in question have been rendering those vehicles 'inoperative,' in violation of the Safety Act. The same principle would apply to a service station that removed an airbag or a safety belt from a vehicle, since such an action would create a noncompliance with the occupant protection requirements of NHTSA's standards. You also asked for our comments on whether Florida's statutes are preempted by these suits. We assume that you are referring to the provision of Florida law that prohibits the operation of any vehicle in the State of Florida that has glazing with less than 35 percent light transmittance. This statute, and similar statutes adopted by other states, do not purport to legitimize conduct -- the rendering inoperative of glazing by tint installation firms -- that is illegal under the Safety Act. Thus, there is no conflict with Federal law, and Florida may continue to enforce its operating rules. I hope that this responds to your questions. If we can be of further assistance, please let me know. Sincerely, Paul Jackson Rice Chief Counsel"; |
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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: aiam1553OpenMr. John W. Lolley, Lolley's Inc., Long Hill Road, Gray, ME 04039; Mr. John W. Lolley Lolley's Inc. Long Hill Road Gray ME 04039; Dear Mr. Lolley: Thank you for your letter of July 15, 1974, concerning you responsibilities as a manufacturer.; Since you shorten frames and mount fifth wheels on new trucks, you ar either an intermediate or final stage manufacturer. I have enclosed Parts 566, 567, 568, and 573 for your information. In addition, I have enclosed a form, entitled 'Federal Motor Vehicle Safety Standards and Regulations' that will enable you to obtain these documents.; If you have any questions on the above, please write me or call Mr David Fay, of my staff, on (202) 426-2817.; Sincerely, Roger H. Compton, Director, Engineering Systems Staff, 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.