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
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ID: aiam1718OpenMr. Newman V. Gill, Marketing Manager, Barns (sic) Lumber and Manufacturing Co., 2813 Lombardy Lane, P.O. Box 20160, Dallas, TX 75220; Mr. Newman V. Gill Marketing Manager Barns (sic) Lumber and Manufacturing Co. 2813 Lombardy Lane P.O. Box 20160 Dallas TX 75220; Dear Mr. Gill: This responds to your November 21, 1974, request for a determinatio that the Barnes Models RTY, RT-XF, RTDF, RTCF, RTA, and GWPHD trailers all qualify as 'Heavy hauler trailers' and, as such, are not required to meet the requirements of Standard No. 121, *Air brake systems, until September 1, 1976.; 'Heavy hauler trailer' is defined in the standard as follows: >>>'Heavy hauler trailer' means a trailer with one or more of th following characteristics:; (1) Its brake lines are designed to adapt to separation or extension o the vehicle frame, or; (2) Its body consists only of a platform whose primary cargo-carryin surface is not more than 40 inches above the ground in an unloaded condition, except that it may include sides that are designed to be easily removable and a permanent 'front-end structure' as that term is used in S 393.106 of this title.<<<; The TRY, (sic) RT-XF, RTDF, RTCF, and RTA models appear to have brak lines that are designed to adapt to extension of the vehicle frame.; We would consider the cargo-carrying surface to the GWPHD to be th horizontal portion of the frame rails, and that it therefore would have a bed-height of less than 40 inches.; I would like to emphasize that your vehicles appear to qualify for thi exemption, but that it exists only until September 1, 1976. Each vehicle manufactured after that date must conform to the requirements of the standard.; Yours truly, Richard B. Dyson, Acting Chief Counsel |
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ID: aiam2837OpenMr. George C. Nield, President, Automobile Importers of America, 900 17th Street, N.W. Suite 100, Washington, DC 20006; Mr. George C. Nield President Automobile Importers of America 900 17th Street N.W. Suite 100 Washington DC 20006; Dear Mr. Nield: This responds to your recent letter asking whether passive safety belt are exempt from the requirements of Safety Standard No. 209, *Seat Belt Assemblies*.; The answer to your question is yes, with one exception. Paragrap S4.5.3.4 of Safety Standard No. 208, *Occupant Crash Protection*, specifies that passive safety belts that are not required for the vehicle to meet the perpendicular frontal crash protection requirements of the standard must meet the requirements of Standard No. 209. Therefore, only passive belts that are installed to meet the frontal crash protection requirements of Standard No. 208 are exempted from the requirements of Standard No. 209.; Sincerely, Joseph J. Levin, Jr., Chief Counsel |
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ID: aiam3752OpenMoni Marcus, P. Eng., Chief Engineer, Flyer Industries Limited, 64 Hoka Street, Box 245 Transcona P.O., Winnipeg, Manitoba, Canada R2C 3T4; Moni Marcus P. Eng. Chief Engineer Flyer Industries Limited 64 Hoka Street Box 245 Transcona P.O. Winnipeg Manitoba Canada R2C 3T4; Dear Mr. Marcus: This responds to your letter to Mr. Kratzke of my staff, asking for clarification of the requirements of Standard No. 217, *Bus Window Retention and Release* (49 CFR S 571.217). You stated that your company's transit bus models use eight large windows as large as emergency exits to satisfy the emergency exit requirements of Standard No. 217, and that the entrance and exit doors are not classified as emergency doors. Accordingly, you stated that the entrance and exit doors do not 'have to be tested for Standard No. 217 requirements.' This is not wholly correct.; Standard No. 217 sets forth two basic requirements. These are (1 window retention requirements, which must be met by *all* windows in a new bus, except for the windshield, and (2) requirements applicable to emergency exits. As I pointed out in a letter to Mr. Moss, of your staff, the window retention requirements apply to all front door glazing which exceeds 8 inches in diameter, and this agency does test such glazing for compliance with the standard. Hence, while you may be correct in asserting that a door not designated as an emergency door would not be tested for compliance with the emergency exit requirements, you are incorrect if you are asserting that the glazing on such a door would not be tested for compliance with the window retention requirements.; Your letter went on to state that, although your entrance and exi doors are not classified as emergency exits, most local transit authorities have requested you to add a decal instructing people how to open the doors in case of an emergency. You then stated your opinion that the addition of these decals would not change the status of the doors to emergency exits, so the doors would not be required to meet the Standard No. 217 push force requirements applicable to emergency doors. This conclusion is incorrect.; Standard No. 217 specifies minimum criteria for emergency exits whic must be met by all new buses, and your letter states that your transit bus models do not need to count the entrance and exit doors on the buses to satisfy these criteria. Thus, absent other factors, those doors would not be required to comply with the portions of the standard applicable to emergency doors. However, affixing a decal, such as the one enclosed with your letter, in the area of those doors is labeling the door as an emergency exit. It is reasonable for riders of the bus to assume that a door which is labeled by the manufacturer with instructions in case of an emergency and which is intended by the local transit authority to be used as an exit in case of an emergency is in fact a door which can be used as an emergency exit. Given the likelihood of the use of the door as an emergency exit when it is so labeled, it is important that the door comply with the requirements applicable to emergency doors in Standard No. 217, and this agency has uniformly required this of all doors labeled with instructions for use in case of an emergency.; For your information, I have enclosed a copy of a letter reaching thi same conclusion which was sent to another manufacturer. Contrary to the understanding expressed in your letter, this agency has never sent a letter to a manufacturer stating that doors labeled with emergency instructions were not subject to the requirements of Standard No. 217 applicable to emergency doors.; Should you need any further information or have further questions o this subject, please contact Mr. Kratzke at this address or at (202) 426-2992.; Sincerely, Frank Berndt, Chief Counsel |
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ID: aiam4097OpenMs. Carol Dingledy, Communications Supervisor, Cosco Inc., 2525 State Street, Columbus, IN 47201; Ms. Carol Dingledy Communications Supervisor Cosco Inc. 2525 State Street Columbus IN 47201; Dear Ms. Dingledy: This responds to your letter to Steve Kratzke of my staff, askin several questions about the effects of an amendment to the buckle force requirements in Standard No. 213, *Child Restraint Systems* (49 CFR S571.213). Buckles used on child restraints manufactured on or after February 16, 1986, must release with a minimum of 9 pounds force and a maximum of 14 pounds force. Buckles used on child restraints manufactured between January 1, 1981, and February 15, 1986, were required to release with a minimum of 12 pounds applied force and a maximum of 20 pounds applied force. Buckles used on child restraints manufactured before January 1, 1981, were required to release with a maximum of 20 pounds applied force. You asked with which buckle release force requirements replacement buckles provided by your company should comply. Assuming that the replacement buckles are to be installed by you or dealers, distributors, or repair businesses, the answer is that the buckles may, at your option, comply with either the release force requirements applicable to child restraint buckles as of the date of manufacture of the child restraint *or* with the current buckle release force requirements.; Standard No. 213, like all of our safety standards applicable to item of motor vehicle equipment, does not apply to the equipment after its first purchase in good faith for purposes other than resale. This general rule is, however, limited by the provisions of section 108(a)(2)(A) of the Safety act (15 U.S.C. 1397(a)(2)(A)), which specifies: 'No manufacturer, distributor, dealer or motor vehicle repair business shall knowingly render inoperative...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....' Please note that these prohibitions do not apply to the child restraint owner rendering inoperative some element of design installed on his or her child restraint. Hence, replacement buckles that are sold to and installed by child restraint owners are not required to comply with the provisions of Standard No. 213.; However, if you as a manufacturer, or any dealers, distributors, o repair businesses were to remove complying buckles from a child restraint and replace them with buckles that did not comply with Standard No. 213, this would violate section 108(a)(2)(A). This result arises because buckles with the specified release force levels were installed on an item of motor vehicle equipment (the child restraint system) in compliance with an applicable Federal motor vehicle safety standard (Standard No. 213). Section 109 of the Safety Act (15 U.S.C. 1398) specifies that each violation of section 108(a)(2)(A) subjects the violator to a potential $1,000 civil penalty.; Assuming that you or your dealers and distributors will be installin the replacement buckles, section 108(a)(2)(A) give you an option of which release force requirements the replacement buckles must meet. In connection with several other standards that have been amended, the National Highway Traffic Safety Administration has stated its opinion that a manufacturer, distributor, dealer, or repair business does *not* knowingly render inoperative an element of design by replacing components installed in satisfaction of a safety standard with other components used in newer items of the same type in satisfaction of the same standard, even if the newer version of the standard imposes less stringent performance requirements. See, for example, the enclosed opinion issued when Standard No. 121, *Air Brake Systems*, was amended, 42 FR 26279, May 23, 1977. In this context, this opinion means that child restraint manufacturers may install replacement buckles that either:; >>>1. comply with the requirements of Standard No. 213 as of the dat the child restraint was manufactured, or; 2. comply with the current requirements of Standard No. 213.<<< If you have any further questions, please let me know. Sincerely, Erika Z. Jones, Chief Counsel |
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ID: aiam2840OpenMr. Irving A. Cohen, Goulston & Storrs, One Federal Street, Boston, MA, 02110; Mr. Irving A. Cohen Goulston & Storrs One Federal Street Boston MA 02110; Dear Mr. Cohen: This is (sic) responds to your May 26, 1978, letter asking severa questions about the applicability of Standard No. 302, *Flammability of Interior Materials*, to your client, a fabric manufacturer.; In your first question, you ask whether the National Highway Traffi Safety Administration (NHTSA) alone regulates the flammability of seat covers or whether other agencies are involved. We know of no other agency involved in the regulation of motor vehicle seat covers.; Your second question asks whether the manufacturer of the fabric or th manufacturer of the vehicle or seat cover would be responsible for compliance with the standard. Since Standard No. 302 is a vehicle standard, the manufacturer of the vehicle would be responsible for ensuring compliance with it, not the manufacturer of the fabric. For replacement seat covers, the installer of those covers, if it is a repair business, manufacturer, or dealer, would be required to ensure that it was not rendering inoperative compliance of the original seat covers with Standard No. 302 and would be responsible for installing only complying seat covers.; Your final question asks who is responsible for recalls and othe agency requirements, the vehicle manufacturer or the fabric manufacturer. Once again, since this is a vehicle standard, the vehicle manufacturer must comply with our requirements, not the fabric manufacturer. In conclusion, your client as a manufacturer of fabric is not responsible for compliance with the agency's flammability standard or the recall and remedy regulations.; Sincerely, Joseph J. Levin, Jr., Chief Counsel |
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ID: aiam1295OpenMr. Tatsuo Kato, Nissan Motor Co., Ltd., 560 Sylvan Avenue, Englewood Cliffs, NJ 07632; Mr. Tatsuo Kato Nissan Motor Co. Ltd. 560 Sylvan Avenue Englewood Cliffs NJ 07632; Dear Mr. Kato: This is in reply to your letter of September 25, 1973, asking whethe the fuel spillage measurement specified in Standard No. 301 is an average rate of one ounce per minute (your Item A) or an actual rate. (Your Item B); Your item B is correct. Fuel spillage shall not exceed one ounce pe minute in any one of the fifteen minutes of the observed period.; Yours truly, Richard B. Dyson, Assistant Chief Counsel |
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ID: aiam3302OpenMr. George Beggs, Mechanical Plastics Corp., Castleton Street, Pleasantville, NY 10570; Mr. George Beggs Mechanical Plastics Corp. Castleton Street Pleasantville NY 10570; Dear Mr. Beggs: This responds to your April 28, 1980, letter asking several question about your responsibility as a manufacturer if you modify a Volkswagen by the addition of a recreational device (Hatchpack). The modification that you propose appears to be substantial in that it might involve a significant alteration of the vehicle rear and roof structures.; Before addressing your specific questions, I would like to give yo some general background information. First, the agency does not give advance approvals of vehicles or equipment. It is the responsibility of a manufacturer to ensure that its vehicles or equipment comply with the applicable requirements of all of our safety standards. A manufacturer then certifies that its vehicles or equipment comply with all applicable standards. For example, when your device is added to a new motor vehicle prior to its first sale, the person who modifies the vehicle would be an alterer of a previously certified motor vehicle and would be required to certify that, as altered, the vehicle continues to comply with all of the safety standards affected by the alteration. You will find the specific certification requirements for alterers in Volume 49 of the Code of Federal Regulations at Part 567.7, *Certification*. On the other hand, you as the manufacturer of the Hatchpack device would have no certification requirements, because we have no safety standards applicable to your equipment.; From the general discussion in your letter, you appear to wan information on safety standards for which you would be responsible. Further, you state that Volkswagen has indicated its concern about the compliance of its vehicle with the crashworthiness safety standards if it is modified as you propose. As we stated above, as an equipment manufacturer, you would not be responsible for the compliance of any safety standard since we have no equipment standards applicable to the device that you manufacture. However, the installer of the device on a new vehicle would be responsible for ensuring that the vehicle continues to comply with all affected safety standards. The installer will probably need your help in making its certification. Therefore, we suggest that you closely confer with Volkswagen to learn which safety standards they feel might be violated by the addition of your equipment. With this information, you can conduct testing or undertake engineering analyses of your device as mounted on the vehicle to see whether Volkswagen's fears have merit. If you can assure yourself that the vehicle as modified will continue to comply with the safety standards, then you can pass this information along to the installer of the equipment who could then certify the vehicle in compliance.; The following are the responses to your specific questions. 1. Under what section of the M.V. safety codes does our product fall if it is to be installed and sold on new automobiles by licensed new car dealers?; As I stated above, the addition of this equipment to a new vehicl means that the installer of the equipment must attach an alterer's label to the vehicle indicating that it continues to comply with all of the safety standards affected by the alteration. Therefore, the installer would be responsible for any safety standard that might be affected by the installation.; 2. Under what sections of the M.V. safety codes does our product fall if it is to be installed by an independent accessory installer onto a new automobile which is then sold as a new vehicle by a licensed new car dealer?; The answer to this question is the same as the answer to questio number 1.; 3. Under what section of the M.V. safety codes does our product fall if it is to be installed by an automobile manufacturer as a factory option for new vehicles which are then to be sold by licensed new car dealers?; If the automobile manufacturer installs the device, that manufacture simply certifies the vehicle in compliance with all safety standards as it must do with any vehicle it produces.; 4. Under what section of the M.V. safety codes does our product fall i it is to be installed by an automobile owner/user?; There are no safety standards or other regulations applicable t modifications made to vehicles by their owners if the modifications are entirely made by the vehicles' owners. If a business such as a garage were to make the modification, it would have to make sure that it did not knowingly render inoperative the compliance of the vehicle with any safety standard. However, since the vehicle would be used, such a business would not be required to attach a certification label.; 5. In each of the cases described in questions No. 1, No. 2, No. 3, an No. 4, who are the parties responsible for certifying to the N.H.T.S.A. that the product is in compliance with the required standards?; No person is required to certify to the NHTSA that a vehicle or produc complies with the requirements. In certain instances, a certification label must be attached to the vehicle. We have indicated in our response to each of the preceding questions when labels must be attached and by whom.; 6. In each of the cases described in questions No. 1, No. 2, No. 3, an No. 4, who are the liable parties in the event of injury or death as a result if (sic) improper installation?; If the improper installation results in a noncompliance with a safet standard or with a defect related to motor vehicle safety, the agency would hold the installer primarily responsible. If, however, we were to discover that the equipment itself were the cause of the defect or noncompliance, the equipment manufacturer would be responsible to the agency. With respect to private liability that might result from a defect or noncompliance, you should consult with your own attorneys for an answer to this question.; 7. Based on the general information supplied with this letter would th installation of this unit by other than a motor vehicle manufacturer require an 'alterers' label or certification?; As we indicated earlier, the answer to this question is yes if th installation is made on a new motor vehicle that has been previously certified by its manufacturer.; 8. Under which, if any, of the cases described in questions No. 1, No 2, No. 3, and No. 4 would there be an N.H.T.S.A. requirement for a fuel system integrity crash test?; The NHTSA does not require that any manufacturer perform a crash tes if it can prove that the vehicle would comply with the requirements by some other means, such as design analysis. It is impossible for us to tell from your drawings whether your device would likely impact the fuel system. Volkswagen can probably be helpful in providing information in this area. If some impact on the fuel system is likely, testing or analysis would be required in each of the first three instances raised in your questions. No testing is ever required for the modification of used vehicles by their owners.; 9. What form of assurances might N.H.T.S.A. require from Mechanica Plastics Corp. for the Hatchpack product?; The NHTSA requires no advance forms of certification or assurances fro manufacturers that their products comply with safety standards. Our enforcement scheme is one of self- certification where the agency might subsequently purchase and test a vehicle for compliance with the standards.; 10. What form of assurances might N.H.T.S.A. require from th installing party as described in questions No. 1, No. 2, No. 3, and No. 4?; The answer to this question is the same as the answer to questio number 9.; We hope that this clarifies your responsibilities and duties wit respect to the device that you propose to manufacture. Again, we strongly encourage you to consult with Volkswagen engineers who can be the most helpful in telling you of the standards that you are likely to impact with your device. If you have any further questions, please contact Roger Tilton of my staff at 202-426-9511.; Sincerely, Frank Berndt, Chief Counsel |
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ID: aiam2143OpenMr. Donald W. Taylor, Manager, Product Safety and Quality, Volvo of America Corporation, Rockleigh, NJ 07647; Mr. Donald W. Taylor Manager Product Safety and Quality Volvo of America Corporation Rockleigh NJ 07647; Dear Mr. Taylor: This responds to Volvo of America's October 9, 1975, question whether truck equipped with an air-assisted hydraulic brake system with hydraulic push through capability and, in the towing vehicle configuration, a source of compressed air for air braked trailer operation is subject to Standard No. 121, *Air Brake Systems*.; From your description of the system and the materials that accompanie your letter, the truck does not qualify as an air-braked vehicle to which the standard applies. The fact that it is capable of operation in combination with an air-braked vehicle and supplies the compressed air for braking that vehicle does not affect the truck's classification as an hydraulic-braked vehicle.; At the time Standard No. 121 was developed, it covered virtually all o the trucks and truck- tractors in the heaviest categories. In planning and making your decisions to introduce hydraulic-braked vehicles in these weight categories, you should be aware that this agency is planning to cover all such vehicles with the basic performance requirements presently contained in Standard No. 121.; Sincerely, Frank Berndt, Acting Chief Counsel |
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ID: aiam4994OpenMr. Bill Willett 1609A Sumner Drive Mobile, AL 36605; Mr. Bill Willett 1609A Sumner Drive Mobile AL 36605; Dear Mr. Willett: This responds to your letter of April 17, 1992, wit repect to motor vehicle lighting. You believe that a 'flickering brake light is an improvement to the existing dim-bright red light now used.' The light you have in mind is one which 'flashes on and off at a faster rate than that of the turn signal and emergency flashers.' The light is intended 'to alert the driver that the brakes are applied as long as the brakes are used . . . .' You have asked 'Is there any Federal law preventing me from doing research by adding another device to the vehicle lights.' Federal Motor Vehicle Safety Standard No. 108, Lamps, Reflective Devices, and Associated Equipment, requires that stop lamps be steady-burning when the brakes are applied. The National Traffic and Motor Vehicle Safety Act prohibits a 'manufacturer, distributor, dealer, or motor vehicle repair business' from any modification that renders wholly or partially inoperative motor vehicle equipment, such as stop lamps, installed pursuant to a standard such as Standard No. 108. Were the existing stop lamps to be rewired to flash, we would regard the change from steady burning to flashing as rendering the stop lamps partially inoperative within the meaning of this prohibition. However, please note that the prohibition includes only four categories of persons, and does not apply to modifications made by a 'survey group member' who is not within one of those categories. Nor does it apply to modifications made by a vehicle owner. In addition, you should check with the authorities in Alabama to ensure that your modifications do not violate any provision of the State motor vehicle code. Sincerely, Paul Jackson Rice Chief Counsel; |
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ID: aiam0484OpenMr. Harold T. Halfpenny, Halfpenny, Hahn & Roche, 111 West Washington Street, Chicago, IL, 60602; Mr. Harold T. Halfpenny Halfpenny Hahn & Roche 111 West Washington Street Chicago IL 60602; Dear Mr. Halfpenny: This is in reply to your letters of October 18, 1971, and November 1 1971, to Mr. Douglas Toms, Administrator, National Highway Traffic Safety Administration, concerning the 'Panic-Stop' signal system from Donel Corporation.; You are correct in your interpretation that Federal Motor Vehicl Safety Standard No. 108 is not applicable to the 'Panic-Stop' system when this system is not installed on motor vehicles as original equipment. The motor vehicle laws and regulations of the individual States, are, however, applicable to the 'Panic-Stop' system when sold and used as aftermarket equipment.; Sincerely, E. T. Driver, Director, Office of Operating Systems, Moto Vehicle Programs; |
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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.