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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| search results table | |
ID: aiam1131OpenMr. Lawrence D. Beshore, Femco, Inc., P.O. Box 687, 500 North Bypass, McPherson, KS 67460; Mr. Lawrence D. Beshore Femco Inc. P.O. Box 687 500 North Bypass McPherson KS 67460; Dear Mr. Beshore: This is in reply to your letter of April 16, 1973, inquiring whethe any Federal laws apply to your building and installation of a man-lift (pictures of which you enclose) in a completed pick-up truck. You state you understand that if the man-lift is installed on a completed vehicle, you are not considered the final-stage manufacturer.; Based on the information you have provided us, we believe you interpretation to be correct. It does not appear that you have altered the pick-up truck in a way that would make your company responsible for conformity with Federal safety standards or regulations.; The NHTSA has proposed certain requirements for vehicle alterers (cop enclosed). These requirements would very likely apply to you, when effective, if the addition of the man-lift occurs before the purchase of the pick-up truck for a purpose other than resale.; Yours truly, Richard B. Dyson, Assistant Chief Counsel |
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ID: aiam4763OpenSusan Birenbaum, Esq. Acting General Counsel United States Consumer Product Safety Commission Washington, DC 20207; Susan Birenbaum Esq. Acting General Counsel United States Consumer Product Safety Commission Washington DC 20207; "Dear Ms. Birenbaum: This responds to your letter asking whether product would be considered an item of 'motor vehicle equipment,' within the meaning of the National Traffic and Motor Vehicle Safety Act (the Safety Act). I apologize for the delay in this response. The product in question is called 'kwik kool' and is intended to improve the performance of motor vehicles' air conditioning systems. The packaging and labeling for this product that were enclosed with your letter indicate that 'kwik kool' is intended exclusively for use with a motor vehicle and by ordinary users of motor vehicles. We conclude that this product is 'motor vehicle equipment.' As you are aware, section 102(4) of the Safety Act, 15 U.S.C. 1391(4), defines, in relevant part, the term 'motor vehicle equipment' as: any system, part, or component of a motor vehicle as originally manufactured or any similar part or component manufactured or sold for replacement or improvement of such system, part, or component or as any accessory, or addition to the motor vehicle . . . 'Kwik kool' is an aerosol component that appears to be manufactured and sold for the improvement of motor vehicle air conditioning systems. As such, it is 'motor vehicle equipment' within the meaning of the Safety Act. You noted in your letter that the Consumer Product Safety Act excludes items of 'motor vehicle equipment' from those 'consumer products' subject to the authority of the Consumer Product Safety Commission under that Act. This agency, on the other hand, has express statutory authority to investigate allegations that an item of motor vehicle equipment contains a defect related to motor vehicle safety. Pursuant to the request in your letter, we have forwarded the complaint enclosed with your letter to our Office of Defects Investigation. If you have any questions or would like some additional information about this topic, please feel free to contact Mr. Marvin Shaw of my staff at this address or by telephone at (202) 366-2992. Sincerely, Paul Jackson Rice Chief Counsel"; |
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ID: aiam1561OpenGerhard P. Riechel, Esq.,Volkswagen of America, Inc.,Englewood Cliffs, New jersey 07632; Gerhard P. Riechel Esq. Volkswagen of America Inc. Englewood Cliffs New jersey 07632; Dear Mr. Riechel:#This responds to your July 1, 1974, letter concernin Volkswagen's petition to exempt its pre-bent vacuum hose from some requirements of STandard No. 106-74, *Brake hoses*. You requested that we confirm that an in-line vacuum check valve is not regulated under the standard, and that the standard's use of 'light duty' and 'heavy duty' vacuum hose terminology corresponds to the use of those terms in the SAE Standard J1403a. We respond to the Volkswagen petition in a letter of July 2, 1974, to Mr. J.W. Kennebeck of Volkswagen.#You are correct in your conclusion that an in-line check valve like the value in Volkswagen's pre- bent vacuum line is not a brake hose fitting subject to the requirements of Standard No. 106-74. #The National Highway Traffic Safety Administration tends to make the same distinction between light and heavy duty vacuum hose types as is made by the SAE Standard J1403a, which is based in the thickness of the hose wall. In addition to those sizes listed by the SAE we have added 9/32-inch hose.#Yours truly,Richard B. Dyson,Assistant Chief Counsel; |
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ID: aiam4299OpenMs. Paula J. Redford, Manager, Free Enterprise Company, 5417 Paseo, Kansas City, MO 64110; Ms. Paula J. Redford Manager Free Enterprise Company 5417 Paseo Kansas City MO 64110; Dear Ms. Redford: This responds to your March 12, 1976, request for a listing of Federa motor vehicle safety standards that apply to the manufacture of a fiberglass hardtop for installation on a Jeep. I am assuming that this top is an aftermarket item and is not incorporated by the Jeep Corporation as the vehicle roof of its product.; The only Federal motor vehicle safety standard applicable to this ite of aftermarket motor vehicle equipment is Standard No. 205, *Glazing Materials*, 49 CFR 571.205. Standard No. 205 specifies requirements for glazing materials used in motor vehicles and motor vehicle equipment, including a vehicle top such as you describe. Any glazing material used in the construction of your Jeep top must be certified as being in compliance with Standard No. 205, even though the top itself does not have to be certified. Generally, the prime glazing manufacturer or the glazing fabricator certifies the glazing, so your main concern as manufacturer of the Jeep top is to make certain that you use glazing that has been certified as being in compliance with the standard. If you obtain sheets of glazing from a prime glazing manufacturer and fabricate or mold the glazing yourself, you must mark and certify the glazing as specified in paragraphs S6.4 and S6.5 of Standard No. 205. A copy of the standard is enclosed for your information.; Sincerely, Stephen P. Wood, Assistant Chief Counsel |
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ID: aiam5522OpenMr. Robert E. Fouts President Earl's Performance Products 189 W. Victoria St. Long Beach, CA 90805; Mr. Robert E. Fouts President Earl's Performance Products 189 W. Victoria St. Long Beach CA 90805; "Dear Mr. Fouts: This responds to your question whether the whip tes specified in Federal Motor Vehicle Safety Standard No. 106, Brake Hoses, can be interpreted to permit a modification to the test apparatus to facilitate your brake hose's meeting the whip test. As explained below, the answer is no. You describe your brake hose as made of 'extruded teflon armored with stainless steel braid.' You state your brake hose can meet all Standard No. 106 test specifications except for the whip test (See S6.3). The whip test specifies fastening the brake hose on a test apparatus at two ends and cycling for 35 hours. You state because of 'aggravated cyclic stress,' your brake hoses fail before 35 hours. To prevent such failures, you wish to add a 'whip dampener,' a movable 'spherical bearing enclosed in a machined housing', to the brake hose. In addition to the two ends, the whip test apparatus will mount the brake hose at the 'whip dampener.' You wish to know whether the whip test can be interpreted to permit mounting the brake hose at the 'whip dampener.' In our opinion, S6.3 cannot be interpreted to permit mounting the brake hose at the 'whip dampener.' S6.3.1 Apparatus specifies a test apparatus that mounts the brake hose at 'capped end fittings' on one end and 'open end fittings' on the other, and specifies no mounting points in between. Thus, a test apparatus that mounts the brake hose at a 'whip dampener,' which is not an end fitting, would not meet Standard No. 106. However, the issues raised in your letter have led us to consider amending the whip test to permit the 'whip dampener' when testing steel braided brake hoses. Accordingly, we will initiate rulemaking to further consider the issues. I hope this information is useful. If you have any further questions, please contact Dorothy Nakama of my staff at (202) 366-2992. Sincerely, Philip R. Recht Acting Chief Counsel"; |
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ID: aiam1832OpenMr. E. J. Banks, The Glass Doctor, 10923 Indian Trail, Suite 109, Dallas, TX 75229; Mr. E. J. Banks The Glass Doctor 10923 Indian Trail Suite 109 Dallas TX 75229; Dear Mr. Banks: This is in reply to your letter dated January 29, 1975, asking whethe a product which you use to repair damaged windshields is prohibited by Federal law or regulation. Your letter was forwarded to our office by the NHTSA Regional Administrator in Fort Worth. You describe the repair process which you use as one in which the air in a damage spot or crack in the windshield is displaced by the product in a liquid form. As this product hardens it bonds itself to the glass, making the damaged area stronger than the other areas of the glass.; There are no Federal laws or regulations which prohibit the use of suc a material or process in the repair of windshields which have previously been installed in vehicles and damaged in use. Using such a material or process in a *new* (but damaged) windshield (such as in shipment) could cause the windshield to fail to meet the performance requirements of Motor Vehicle Safety Standard No. 205 (49 CFR S 571.205) and we would therefore discourage its use in new windshields.; We are pleased to be of assistance. Yours truly, Richard B. Dyson, Assistant Chief Counsel |
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ID: aiam0720OpenMs. Donna M. Barnard, Owner, Scott's Trailer Market, 2020 E. Fremont Street, Las Vegas, NV 89101; Ms. Donna M. Barnard Owner Scott's Trailer Market 2020 E. Fremont Street Las Vegas NV 89101; Dear Ms. Barnard: This is in reply to your letter of May 10, 1972 to Mr. E.T. Drive requesting further clarification of the Tire Identification and Record Keeping regulations concerning your responsibility as a seller of trailer coaches.; The regulation does not distinguish between the responsibility o manufacturers, distributors and dealers of trailer coaches as opposed to manufacturers, distributors and dealers of other type vehicles. Therefore, a manufacturer of a trailer coach is required, pursuant to section 574.10 of the regulation, to maintain a record of tires shipped on or in the vehicle and the name and address of the purchaser of the vehicle. The manufacturer is free to use the tire identification system on the tire or any other system as long as the system would enable him to notify the purchaser of the vehicle in the event the tires the vehicle is equipped with become the subject of a recall. Therefore, in most cases, if the manufacturer obtains the name of the purchaser from the seller and is able to identify the tires on the vehicle, he is able to meet this requirement. The method the manufacturer uses to maintain a record of the tires on the vehicle appears to vary, but the efficiency of that record is the responsibility of the manufacturer.; On the other hand, if the vehicle dealer changes tires prior to th sale to the user, the manufacturer is no longer responsible for maintaining the record of the tires on the vehicle. In this case section 574.9(b) of the regulation would apply and the vehicle dealer would have to send the name and address of the purchaser of the vehicle, the tire identification number of the tire on the vehicle, and the dealer's name and address to the manufacturer of the tires.; For your convenience enclosed is a copy of the regulation. Sincerely, David Schmeltzer, Assistant Chief Counsel |
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ID: aiam1998OpenMr. Carl Morton, County of Los Angeles Road Department, 5530 West 83rd Street, Los Angeles, California 90045; Mr. Carl Morton County of Los Angeles Road Department 5530 West 83rd Street Los Angeles California 90045; Dear Mr. Morton: Please forgive the delay in responding to your letter of April 28 1975, concerning tires used on pull brooms.; Federal Motor Vehicle Safety Standard No. 119, *New pneumatic tires fo vehicles other than passenger cars*, (copy enclosed), specifies labeling and performance requirements for all tires designed for use on pull brooms. This standard applies to all such tires manufactured on or after March 1, 1975. There is presently no requirements, however, that vehicles be equipped with tires conforming to the standard. The National Highway Traffic Safety Administration has proposed and is considering the issuance of a new Standard No. 120, *Tire selection and rims for motor vehicles other than passenger cars*, which would require all new pull brooms manufactured after its effective date to be equipped with tires conforming to Standard No. 119.; Yours truly, Frank Berndt, Acting Chief Counsel |
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ID: aiam5172OpenMr. L. Schmidt 610 Fulton Street Seymour, WI 54165; Mr. L. Schmidt 610 Fulton Street Seymour WI 54165; "Dear Mr. Schmidt: Your letter requesting information about regulation that might affect substitution of a diesel engine for a 'worn out' gasoline engine has been referred to my office for reply. I apologize for the delay in answering. By way of background, NHTSA is authorized by the National Traffic and Motor Vehicle Safety Act (Safety Act) to issue Federal motor vehicle safety standards (FMVSS's) that set performance requirements for new motor vehicles and new items of motor vehicle equipment. NHTSA is not authorized to certify or approve motor vehicles or motor vehicle equipment for compliance with the FMVSS's. Instead, under the Safety Act, each manufacturer of a motor vehicle or item of motor vehicle equipment is responsible for certifying that its products meet all applicable safety standards. We do not have any requirements that would apply to the conversion of a vehicle from gasoline to diesel if the conversion is made by you on your own vehicle. The Safety Act and our regulations generally do not apply to a vehicle after the vehicle is sold to a consumer for purposes other than resale. Although the Safety Act prohibits certain entities from tampering with or removing federally required safety systems, the prohibition does not apply to modifications by a vehicle owner to his or her own vehicle. If the diesel engine were substituted for the gasoline engine by a vehicle manufacturer, distributor, dealer or repair business, the installer would not have to certify the vehicle as described above. Instead, 108(a)(2)(A) of the Safety Act requires any of these parties making the substitution to ensure that it did not knowingly render inoperative any device or system of design installed in compliance with any applicable safety standard, such as Standard 301, 'Fuel System Integrity' (49 CFR 571.301, copy enclosed). The purpose of Standard 301 is to reduce deaths and injuries occurring from fires that result from fuel spillage during and after motor vehicle crashes. The prohibition of 108(a)(2)(A) does not apply to individual vehicle owners who alter their own vehicles. Thus, under our requirements, individual owners may install any item regardless of its effect on compliance with the FMVSS's. However, NHTSA encourages vehicle owners not to tamper with vehicle safety equipment if the modification would degrade the safety of the vehicle. You also asked if any law forbade diesel conversions in zones within your state in which emissions tests are required. We suggest you contact the Environmental Protection Agency for any questions concerning emissions and air quality. The general telephone number for the EPA is (202) 382-2090. You should also contact the state of Wisconsin for emissions testing regulations. I hope this information is helpful. If you have any more questions about NHTSA's safety standards, please contact David Elias of my staff at this address or by telephone at (202) 366-2992. Sincerely, John Womack Acting Chief Counsel Enclosure"; |
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ID: aiam0370OpenMr. Yoshiyuki Mizuno, Engineering Representative, Nissan Motor Co., Ltd., Liaison Office in U.S.A., 400 County Avenue, Secaucus, NJ, 07094; Mr. Yoshiyuki Mizuno Engineering Representative Nissan Motor Co. Ltd. Liaison Office in U.S.A. 400 County Avenue Secaucus NJ 07094; Dear Mr. Mizuno: This is in reply to your letter of May 10, 1971, concerning coverin material for seats and door trim that is used solely to protect the interior of the vehicle during transportation from the manufacturer to the dealer. You have asked whether this covering material is required to comply with the flammability requirements of Standard No. 302.; Whether the material must comply with the standard depends upon whethe it is likely to be used in a significant number of cases by the purchaser as part of the motor vehicle. You have stated that the only purpose of the material is 'to insure the delivery of a car in which the interior is in good condition.' It is important that this intent be carried out in practice, if the material is not to be considered vehicle interior material subject to the standard. Two criteria which would be considered in determining whether the material is covered by the standard are (1) whether it is placed in the vehicle in a way that its use after purchase is unlikely, and (2) what steps the manufacturer has taken to see that it is removed before sale to the purchaser.; We cannot make a final determination as to whether such material mus meet the requirements without more information, particularly with respect to the questions noted above. However, if Nissan does take appropriate steps to ensure that such material will not be used as a seat cover by the purchaser, then the material would not be required to meet the requirements of the Standard.; We are pleased to be of assistance. Sincerely,Lawrence R. Schneider, Acting Chief Counsel |
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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.