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: 08-002983 slip on seat coverOpenMs. Ramona Hutton 167 Deep Woods Way Ormond Beach, FL 32174 Dear Ms. Hutton: This responds to your letter asking about requirements applying to aftermarket slip-on seat covers for motor vehicles. In particular, you were interested in flammability requirements that would be applicable to the product. By way of background, the National Highway Traffic Safety Administration (NHTSA) is authorized to issue Federal Motor Vehicle Safety Standards (FMVSSs) that set performance requirements for new motor vehicles and items of motor vehicle equipment (see 49 U.S.C. Chapter 301, National Traffic and Motor Vehicle Safety Act (Safety Act)). NHTSA does not provide approvals of motor vehicles or motor vehicle equipment. Instead, manufacturers are required to self-certify that their products conform to all applicable safety standards that are in effect on the date of manufacture. NHTSA selects a sampling of new vehicles and equipment each year to determine their compliance with applicable FMVSSs. If our testing or examination reveals an apparent noncompliance, we may require the manufacturer to remedy the noncompliance, and may initiate an enforcement proceeding, if necessary, to ensure that the manufacturer takes appropriate action. NHTSA also investigates safety-related defects in motor vehicles and motor vehicle equipment. There is currently no FMVSS that directly applies to aftermarket slip-on seat covers. There are a number of FMVSSs that apply to vehicle seating systems. However, these apply to new complete motor vehicles and not to aftermarket slip-on seat covers. Nonetheless, there are Federal requirements that indirectly affect the manufacture and sale of your product. Under the Safety Act, your product is considered to be an item of motor vehicle equipment. As a manufacturer of motor vehicle equipment, you would have to ensure that your product is free of safety-related defects. I have enclosed an information sheet that briefly describes those responsibilities. In the event that you or NHTSA determines that your seat cover contains a safety-related defect, you would be responsible for notifying purchasers of the defective equipment and remedying the problem free of charge. In addition, 30122 of the Safety Act specifies: A manufacturer, distributor, dealer, or motor vehicle repair business may not knowingly make inoperative any part of a device or element of design installed on or in a motor vehicle or motor vehicle equipment in compliance with an applicable motor vehicle safety standard ... The flammability resistance of the original vehicle is an element of design installed in a motor vehicle in compliance with FMVSS No. 302. Further, some motor vehicles have sensing systems in front seats installed in compliance with FMVSS No. 208, Occupant Crash Protection, and seat-mounted side air bags in compliance with FMVSS No. 214, Side Impact Protection. While it appears unlikely that persons in the aforementioned categories would be installing your product, installation of an item that made inoperative the vehicles compliance with flammability resistance, side or frontal impact protection requirements may subject the commercial entity to penalties for violating 30122. The make inoperative prohibition of 30122 does not apply to the actions of vehicle owners in adding to or otherwise modifying their vehicles or items of motor vehicle equipment. Thus, if your seat cover were installed in vehicles by the vehicle owners, your product need not meet any FMVSSs. Nevertheless, we urge consumers not to degrade the safety of their vehicles. Further, for information on private tort liability, we suggest you contact your private attorney or insurance carrier. State or local jurisdictions have their own traffic safety laws which could affect the flammability resistance of certain items. For information about those requirements, you should contact the State departments of motor vehicles. In your letter, you provided data sheets of a product you are considering using to fire-retard the seat covers. As explained above, we regret to inform you that NHTSA is not able to approve or make any recommendations about the use of the product. I hope this information is helpful. If you have further questions, please contact Deirdre Fujita of my staff at (202) 366-2992. Sincerely yours, Anthony M. Cooke Chief Counsel Enclosure ref:302 d.11/20/08 |
2008 |
ID: aiam2389OpenMr. William R. Rodger, Vice President, Advanced Programs, Rockwell International, 2135 West Maple Road, Troy, MI 48084; Mr. William R. Rodger Vice President Advanced Programs Rockwell International 2135 West Maple Road Troy MI 48084; Dear Mr. Rodger: This responds to Rockwell International's February 23, 1976, reques for confirmation that the deactivation of automatic adjusters is acceptable during burnish procedures of Standard No. 121, *Air Brake Systems*, at the option of the manufacturer.; The procedure that you recommend is not permitted by any provision o Standard No. 121. The NHTSA would consider some provision to deal with the overadjustment of automatic adjusters upon receipt of technical data showing justification for such action. Based on consideration of the data received and a petition for amendment, the agency could commence a rulemaking proceeding in accordance with established procedures.; It should be noted that the option in FMVSS 105-75 that you describ requires that the automatic adjusters be deactivated for the entire test sequence, not just the burnish procedure.; Sincerely, Robert L. Carter, Associate Administrator, Motor Vehicl Programs; |
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ID: aiam5437Open"M. Guy Dorleans Legal Compliance Department Valeo Vision 34, rue St-Andr 93012 Bobigny Cedex France"; "M. Guy Dorleans Legal Compliance Department Valeo Vision 34 rue St-Andr 93012 Bobigny Cedex France"; Dear M. Dorleans: We have received your letter of July 15, 1994, askin whether certain front lamp designs would be permissible under Federal Motor Vehicle Safety Standard No. 108. In the basic front lamp design, the upper beam photometrics of Figure 17A would be provided by Lamps A and B. You have asked whether it is possible to add Lamp D, 'an auxiliary driving beam.' In this variation 'all three A, B and D filaments would be permanently energized together in high beam mode and table 17a (sic) of FMVSS 108 is then fulfilled.' Lamp D meets the photometric requirements of SAE Standard J581 JUN89 Auxiliary Driving Lamps. The photometrics of Figure 17A apply to two-lamp integral beam or two-lamp combination headlighting systems, and the design in your drawing is that of a four-lamp system, subject to the photometrics of Figure 15A. This configuration is not permissible under Standard No. 108. Sincerely, John Womack Acting Chief Counsel; |
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ID: aiam0862OpenMr. J. Richard Schlen, Schlen Body and Equipment Co., P. O. Box No. 229, Carllnville(sic), IL 62626; Mr. J. Richard Schlen Schlen Body and Equipment Co. P. O. Box No. 229 Carllnville(sic) IL 62626; Dear Mr. Schlen: This is in reply to your letter of September 22 to Mr. Ed Leysath o this Office regarding interpretations of FMVSS No. 108 on required mounting of marker lights on your dump trailers.; In answer to your first problem, a combination front clearance and sid marker lamp must meet the requirements for both, therefore, the full 180-degree visibility is required. If you determine that it is not practicable to mount the combination lamp in your alternate location, because of a greater possibility of damage, then separate lamps should be considered.; In answer to your second problem, because of the configuration and en use of your dump semi-trailers, your interpretation that rear clearance lamps mounted in a light box just below the rear trailer crossmember are as high as practicable is correct.; Sincerely, E. T. Driver, Director, Office of Operating Systems, Moto Vehicle Programs; |
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ID: aiam5542OpenMr. Lance Tunick Vehicle Science Corporation P.O. Box 1015 Golden, CO 80402-1015; Mr. Lance Tunick Vehicle Science Corporation P.O. Box 1015 Golden CO 80402-1015; Dear Mr. Tunick: This responds to your FAX of April 19, 1995 requesting clarification of an April 3, 1995, letter from this office. You asked for verification that the 'seat belt anchorages in the following scenario are exempt from the location requirement of Standard No. 210: A vehicle with 2 front seating positions that is fitted with an air bag and manual three-point seat belt at each position, and such restraint meets the frontal crash protection requirements of S5.1 of Standard No. 208 with the air bags alone and with the belts and air bags together, but the belts alone are not crash tested under FMVSS 208.' Your understanding is correct. I hope this information has been helpful. If you have other questions or need some additional information, please contact Mary Versailles of my staff at this address or by phone at (202) 366-2992. Sincerely, John Womack Acting Chief Counsel; |
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ID: aiam5091OpenMr. Chester I. Nielsen, III Vice President Sales Wesbar Corporation P.O. Box 577 West Bend, WI 53095; Mr. Chester I. Nielsen III Vice President Sales Wesbar Corporation P.O. Box 577 West Bend WI 53095; Dear Mr. Nielsen: This responds to your letter of October 21, 1992, t Walter B. McCormick, Jr. (the General Counsel of this Department). You have written for 'further explanation of S5.3.1.1.1 in FMVSS 108.' You have heard that there is an additional interpretation with respect to the location of clearance lamps on boat trailers whose overall width is 80 inches or more, which would allow mounting of these lamps in accordance with a sketch that you enclosed, and you ask for confirmation of this interpretation. We are unaware of any interpretation of this nature. The requirements for the provision and location of clearance lamps on wide boat trailers remain those set forth in Tables I and II of Standard No. 108, with the exceptions set forth in paragraphs S5.1.1.9, S5.3.1.1.1, and S5.3.1.4. Sincerely, Paul Jackson Rice Chief Counsel; |
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ID: aiam5541OpenMr. Lance Tunick Vehicle Science Corporation P.O. Box 1015 Golden, CO 80402-1015; Mr. Lance Tunick Vehicle Science Corporation P.O. Box 1015 Golden CO 80402-1015; Dear Mr. Tunick: This responds to your FAX of April 19, 1995 requesting clarification of an April 3, 1995, letter from this office. You asked for verification that the 'seat belt anchorages in the following scenario are exempt from the location requirement of Standard No. 210: A vehicle with 2 front seating positions that is fitted with an air bag and manual three-point seat belt at each position, and such restraint meets the frontal crash protection requirements of S5.1 of Standard No. 208 with the air bags alone and with the belts and air bags together, but the belts alone are not crash tested under FMVSS 208.' Your understanding is correct. I hope this information has been helpful. If you have other questions or need some additional information, please contact Mary Versailles of my staff at this address or by phone at (202) 366-2992. Sincerely, John Womack Acting Chief Counsel; |
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ID: aiam2087OpenDirector, Office of Standards Enforcement; Director Office of Standards Enforcement; SUBJECT: Certification of Universal Size Motorcycle Helmets You have asked whether a universal motorcycle helmet must b permanently labelled with the DOT label to certify compliance with FMVSS No. 218. As I understand it, these helmets are readily adjustable and can be made to fit the size C headform by means of filler material supplied by the manufacturer for the purpose of allowing such adjustment. Accordingly, they are required to comply with the standard.; The requirements of the standard apply to helmets that fit headfor size C. It is my interpretation that the term 'fit' includes the case where by means of an adjusting mechanism supplied by the manufacturer for the purpose of permitting adjustment to headform size C, *inter* *alia*, the helmet can readily be made to fit headform size C. You should, in testing the helmets for compliance purposes, follow the manufacturer's suggested procedures for fitting the helmet to the size C headform and then proceed as with any other helmet. When other headforms become available, a helmet will be required to pass the requirements for all sizes that it fits.; Frank Berndt, Acting Chief Counsel |
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ID: aiam5259OpenMr. Dennis G. Moore President Sierra Products, Inc. 1113 Greenville Road Livermore, CA 94550; Mr. Dennis G. Moore President Sierra Products Inc. 1113 Greenville Road Livermore CA 94550; Dear Mr. Moore: We have received your letter of August 12, 1993 'requesting a legal clarification detailing where FMVSS 108 requires a Clearance Light to be mounted.' It is clear from your letter that it is the lateral spacing of clearance lamps that concerns you as you believe that it is not uncommon to see them mounted as much as 6 to 8 inches ''inside' the side extremities of huge vehicles.' With respect to lateral spacing, Table II of Standard No. 108 requires clearance lamps to be mounted 'to indicate the overall width of the vehicle . . . .' The standard does not require the lamps to be mounted at the widest point of the vehicle, nor does it require them to be mounted as far apart as practicable. We believe that manufacturers generally try to mount clearance lamps to 'indicate' the overall width of the vehicle, but we recognize that there may be certain circumstances and/or configurations that require mounting of the lamps at something less than the widest point. Sincerely, John Womack Acting Chief Counsel; |
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ID: aiam1256OpenSekurit-Glas Union GmbH, 5 Koln 1, Postfach 101608; Sekurit-Glas Union GmbH 5 Koln 1 Postfach 101608; Dear Sir: This is in reply to your letter of July 19, 1973, requestin information regarding the marking requirements in FMVSS No. 205 for automobile safety glass.; With respect to your request for a copy of the marking requirements they may be found in paragraph S6. of the enclosed copy of the standard, and in section 6 of American National Standard Z26.1 - 1966. The latter standard can be obtained by writing to the American National Standards Institute, 1430 Broadway, New York, New York 10018.; Information on various State requirements should be obtained from Mr Armond Cardarelli, American Association of Motor Vehicle Administrators, Suite 500, 1828 L Street, N.W., Washington, D.C. 20036.; You ask whether marking requirements can be met using a specific forma you include in your letter, and refer to 'Approval' and 'Supplemental' markings. It is not clear to us to what you refer, as we prescribe neither 'approval' nor 'supplemental' markings in the standard, and perhaps we will be better able to answer any questions you may have after you have had an opportunity to review the requirements.; Yours truly, Richard B. Dyson, Assistant 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.