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: aiam0542OpenMs. C. Dianne Mampe, Technical Assistant, Engineering Liaison, British Leyland Motors Inc., 600 Willow Tree Road, Leonia, NJ, 07605; Ms. C. Dianne Mampe Technical Assistant Engineering Liaison British Leyland Motors Inc. 600 Willow Tree Road Leonia NJ 07605; Dear Ms. Mampe: This is in reply to your two letters of June 14, 1972, concerning Moto Vehicle Safety Standard No. 302, 'Flammability of Interior Materials.'; You ask whether the requirement of S4.3 that material not burn no transmit a flame front across its surface at a rate of more than 4 inches per minute includes the flashing of the flame across the surface for only a fraction of a second. The flashing of the flame as you describe it is included within the requirement, and consequently cannot occur at a rate greater than 4 inches-per-minute.; You also ask whether polyethylene covering which does not meet th standard's requirements may be used to protect the interior during shipment, if the material is marked and fitted so that its appearance would ensure that purchasers would not want to use it. You indicate that the manufacturer would also take steps to instruct dealers to remove the material. The NHTSA would consider the material to be outside of the standard's requirements if these steps are taken to prevent it from being used as a seat cover by purchasers.; Yours truly, Richard B. Dyson, Assistant Chief Counsel |
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ID: aiam5310OpenMr. Joe Miller Product Support Manager Load King Box 427 Elk Point, SD 57025; Mr. Joe Miller Product Support Manager Load King Box 427 Elk Point SD 57025; Dear Mr. Miller: This is in response to your FAX of December 10, 1993 You have informed us that Load King manufactures trailers, selling them to a dealer in Minneapolis who, in turn, sells these trailers to customers/users. You would like the dealer 'to do some finish manufacturing for us.' Specifically, you would like the dealer 'to paint the trailers, install operational decals and place the conspicuity striping.' You ask whether 'primed trailers can be moved without conspicuity striping in this case.' The answer is no. Under the National Traffic and Motor Vehicle Safety Act and its regulations, when a completed motor vehicle is delivered to its dealer, it must be certified as conforming to all applicable Federal motor vehicle safety standards, and it must, in fact, comply with all such standards at the time of delivery. Thus, your trailers are required to be equipped with the conspicuity treatment at the time of shipment since the treatment is a requirement of Motor Vehicle Safety Standard No. 108. The Minneapolis dealer, however, may apply paint and decals since this is not required under Standard No. 108 or any other regulation. Were the trailer one that is manufactured in more than one stage, our regulations would permit the final stage manufacturer to apply the conspicuity treatment since that manufacturer is required to affix the necessary certification of compliance with all standards upon completion of the final stage of manufacture. However, painting and application of the conspicuity treatment are regarded as minor finishing operations that do not rise to the level of being a separate stage of manufacturing, and this exception is not available under the facts that have been presented to us. Sincerely, John Womack Acting Chief Counsel; |
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ID: aiam0112OpenMr. R. O. Sornson, Federal Safety Coordinator, Chrysler Corporation, P. O. Box 1919, Detroit, MI 48231; Mr. R. O. Sornson Federal Safety Coordinator Chrysler Corporation P. O. Box 1919 Detroit MI 48231; Dear Mr. Sornson: Thank you for your letter of September 11, 1968, to Mr. J. E. Leysat of this Bureau, concerning the Chrysler Super Lite which you intend to offer as an optional supplemental light on some of the Chrysler 1969 car lines.; You are correct in your understanding that a supplemental light of thi type is not required by Federal Motor Vehicle Safety Standard 108. Standard No. 108 does, however, specify, in Paragraph S3.1.2, that no additional lamp, reflective device, or associated equipment shall be installed if it impairs the effectiveness of the required equipment.; On the basis of our review of your technical literature on the Supe Lite and our observation of limited field demonstrations of the light, it does not appear that the Super Lite will impair the effectiveness of the lighting equipment required by Standard No. 108. It should be noted, however, that, while the incorporation of this lamp in your 1969 automobiles would not be precluded by the Federal Standard, the various States may interpose restrictions as to this lamp.; With respect to the requirements of Standard No. 108, I must point ou that this Bureau does not issue approvals on items of lighting equipment or on vehicle designs incorporating this equipment. Therefore, the above comments are for your information only and in no way relieve the vehicle manufacturer from his responsibility for certifying that the assembled vehicle meets the requirements of the standard.; Sincerely, William Haddon, Jr., M.D., Director |
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ID: aiam2986OpenMr. W. G. Milby, Manager, Engineering Services, Blue Bird Body Company, P.O. Box 937, Fort Valley, GA 31030; Mr. W. G. Milby Manager Engineering Services Blue Bird Body Company P.O. Box 937 Fort Valley GA 31030; Dear Mr. Milby: This responds to your March 1, 1979, letter asking the National Highwa Traffic Safety Administration to withdraw an earlier interpretation of Standard No. 222, *School Bus Passenger Seating and Crash Protection*, which stated that any contactable objects falling within the head protection zone must comply with the head impact and force distribution requirements. The head protection zone might include some areas in the driver's seating location, and therefore, any contactable object in the driver's seating location that falls within the zone must comply with the requirements. The agency declines to alter its interpretation.; The standard is clear in its specification of zones for head for impact and force distribution testing. These zones help to ensure that any contactable objects falling within them will be sufficiently padded to protect a child from serious injury in an accident. The head protection zone for any passenger seat extends into the seat area of the passenger seat immediately in front of it. Similarly, the zone for the front passenger seat might extend into the driver's seating location. You argue that the restraining barrier between the front seat and the driver's seat removes the need for head protection zone requirements in the driver's seating area.; The fact that a restraining barrier separates the driver's seatin location from the passenger seat bears no relevance to the need for head impact protection in the head protection zone for the front passenger seat. The head protection zone extends above and beyond the restraining barrier recognizing the possibility that the heads and upper bodies of larger children are likely to be impelled somewhat beyond the barrier in an accident. The barrier should help to prevent a child from being thrown entirely out of its seating position, but a barrier cannot prevent a child's head from being propelled beyond the barrier in some instances. Since the head protection zone requirements are designed to provide protection in these situations and that protection is needed for all passenger seats including the front seat, the agency will not alter its interpretation of the requirements as they apply to the head protection zone for the front passenger seat.; Sincerely, Frank Berndt, Chief Counsel |
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ID: aiam3694OpenMr. John E. Bennett, Director - Research & Engineering, Truck-Lite Co., Inc., 310 East Elmwood Avenue, Falconer, NY 14733; Mr. John E. Bennett Director - Research & Engineering Truck-Lite Co. Inc. 310 East Elmwood Avenue Falconer NY 14733; Dear Mr. Bennett: This is in response to your letter of April 12, 1983, asking for a interpretation of paragraph S4.6(b) of Motor Vehicle Safety Standard No. 108.; This paragraph states in pertinent part that 'means may be provided t flash...side marker lamps for signalling purposes.' You have first asked whether the rear side marker can be made to flash. You have also asked whether this language may be interpreted as allowing both front and rear side marker lamps to be flashed. The answer to both questions is yes. In the absence of restrictive language, paragraph S4.6 may be interpreted as allowing flashing of either front or rear side marker lamps, or both sets of lamps.; You have also asked whether, where the rear side marker and taillam use the same optical source ('minor filament of a 1157 or similar bulb'), it is acceptable to have an overriding signal visible through the rear side marker lens when the turn signal lamp is actuated. The answer is yes. The standard's prohibition against optical combinations (paragraph S4.1.1) does not preclude this design.; We hope that this answers your questions. Sincerely, Frank Berndt, Chief Counsel |
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ID: aiam4151OpenMr. Jules N. Fiani, Ken-Guard Industries, Inc., P.O. Box 848, Brighton, MI 48116-0848; Mr. Jules N. Fiani Ken-Guard Industries Inc. P.O. Box 848 Brighton MI 48116-0848; Dear Mr. Fiani: Thank you for providing the agency with information about your product the Tot-Loc child safety seat belt buckle shield. Your product is designed to prevent children from inadvertently or intentionally opening the buckle of a safety belt. Your product is a piece of plastic which snaps around and covers the front of a buckle of a safety belt. To open the buckle, a person must insert a car or other key into a slot on top of the plastic cover and depress the safety belt buckle release with the key.; Although we understand your concern that young children not be able t easily get out of a safety belt, we have signification reservations about your product. I hope the following discussion explains our reservations and the effect of our regulations on your product.; Our agency has the authority to issue safety standards applicable t new motor vehicles and certain items of motor vehicle equipment. NHTSA, however, does not approve motor vehicles or motor vehicle equipment, nor do we endorse any commercial products. Instead the National Traffic and Motor Vehicle Safety Act establishes a 'self-certification' process under which each manufacturer is responsible for certifying that its products meet our safety standards. The agency periodically tests vehicles and equipment items for compliance with the standards, and also investigates other alleged safety-related defects.; Although we do not have any standards that directly apply to you product, we do have several statutory provisions that could affect it. Manufacturers of motor vehicle equipment such as your product are subject to the requirements in sections 151-159 of the Vehicle Safety Act concerning the recall and remedy of products with defects related to motor vehicle safety. The agency does not determine the existence of safety defects except in the context of a defect proceeding, and thus is unable to say whether your product might or might not contain such a defect. However, the agency has reservations about your product because of our concern that people be able to easily and quickly operate a safety belt in an emergency. As the agency said last year on the related topic of the force level necessary to operate buckles in child restraints:; >>>The agency's safety concerns over child restraint buckle forc release and size stem from the need for convenient buckling and unbuckling of a child and, in emergencies, to quickly remove the child from the restraint. This latter situation can occur in instances of post-crash fires, immersions, etc. A restraint that is difficult to disengage, due to the need for excessive buckle pressure or difficulty in operating the release mechanism because of a very small release button, can unnecessarily endanger the child in the restraint and the adult attempting to release the child. (50 FR 33722, August 21, 1985).<<<; In addition, use of your product can be affected by sectio 108(a)(2)(A) of the Vehicle Safety Act. That section prohibits commercial businesses from knowingly tampering with devices or elements of design installed in a vehicle in compliance with the Federal motor vehicle safety standards. One requirement of Standard No. 209, *Seat Belt Assemblies*, is that the pushbutton release for a safety belt must have a minimum area for applying the release force. Installation of your device by a commercial business could be prohibited since it apparently would substantially reduce the minimum area available for applying the release force to the safety belt pushbutton. In addition, Standard No. 302, *Flammability of Interior Materials*, requires new safety belts to meet a flammability resistance requirement. Thus, although Standard No. 302 does not directly apply to aftermarket equipment, commercial businesses could not install your device if it would mean that the safety belt no longer met the flammability resistance requirements of Standard No. 302.; The prohibition of section 108(a)(2(A) (sic) does not apply t individual vehicle owners who may install or remove any items of motor vehicle equipment regardless of its effect on compliance with Federal motor vehicle safety standards. However, our policy is to encourage vehicle owners not to remove or otherwise tamper with vehicle safety equipment. Installation of your product by any person could be inconsistent with that policy.; If you have any further questions, please let me know. Sincerely, Erika Z. Jones, Chief Counsel |
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ID: aiam1353OpenMr. Patrick C. Ross, President, B. F. Goodrich Tire Company, 500 South Main Street, Akron, OH 44318; Mr. Patrick C. Ross President B. F. Goodrich Tire Company 500 South Main Street Akron OH 44318; Dear Mr. Ross: This is in reply to your petition, dated May 18, 1973, for amendment to Motor Vehicle Safety Standard No. 109 and the Tire Identification and Recordkeeping regulations (49 CFR Part 574). You request that the standard be amended to except tires having an 'unusual configuration and construction,' from that part of S4.3 which requires safety information to be labeled between each tire's maximum section width and bead. You request a similar exception in Part 574 for the tire identification number. Goodrich has experienced difficulties in placing this information in the proper location in tire molds used to manufacture Goodrich's Space Saver Spare tire. You indicate this is caused by the thinness of the mold, which is apparently necessitated by the folding sidewall characteristics of the tire.; In the case of the Space Saver Spare, Goodrich wants to be able t place the labeling information and the identification number in the shoulder area of the tire. Your request is supported with pictures of a Space Saver Spare that has been run to wear-out yet still retains legible labeling in this area. In your view it is unlikely that this tire will be retreaded. You argue that the location you desire to use, while not between the maximum section width and bead, has the advantage of making the information and identification number visible both when the tire is inflated and deflated. The latter condition is important in this case in that this tire is generally carried in a deflated, folded condition when it is not in use.; We do not believe the facts you present justify an amendment to th standard, and have therefore determined that your petition should be denied. The purpose of requiring safety information and the tire identification number to be placed between each tire's maximum section width and the bead is to ensure, to the greatest extent possible, that the information will remain on the tire throughout its useful life, including a retreading process if the tire is retreaded. In our view, it is not all clear that the alternative location you suggest will still meet this objective. The justification which you provide does not show that labeled information cannot be removed in service or that these tires will not, in fact, be retreaded. We certainly would not object if Goodrich were to place identifying information in separate location in addition to that required by the standard.; With respect to the difficulty you have encountered in placing th information in the specified area, we do not find on the basis of the information you have supplied that the alternative possibilities are impracticable. For example, your letter does not mention whether you have attempted to engrave the safety information and that part of the identification number that is constant into the tire molds. While we understand engraving is generally more expensive and somewhat more inconvenient than branding the mold or using metal plates, we do not believe the added expense and inconvenience, particularly as it is amortized over the life of the mold, to be unreasonable in terms of the safety benefit achieved. It also appears that this labeling, in letters 0.078 inches in height, can be placed just above the rim centering rib, which from the sample submitted with your petition, does not appear to have been damaged upon removal. This location would allow removal of the tire from the mold without deformation of the lettering and would place the required information between the tire's maximum section width and bead. With respect to date codes, for which engraving is unsuited, it appears that the code stamp could be recessed so as to be flush with the mold surface, thus eliminating or substantially reducing the destruction of the lettering during removal.; Sincerely, James B. Gregory, Administrator |
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ID: aiam4501OpenMr. Terry E. Quinn Corporate Director of Quality Hehr International, Inc. PO Box 39160 Los Angeles, CA 90039-0160; Mr. Terry E. Quinn Corporate Director of Quality Hehr International Inc. PO Box 39160 Los Angeles CA 90039-0160; "Dear Mr. Quinn: This responds to your letter of last year concernin Standard No. 205, Glazing Materials. I regret the delay in our response. You explained that your company, Hehr International, is a prime glazing material manufacturer that tempers glazing material used in vehicular windows produced by your company and other companies. You stated that a prospective customer for your tempered glass does not wish to have your trademark appear on the glazing etch of its windows since it is a competitor of yours. You asked whether a prime manufacturer may sell its tempered glass without its distinctive designation or trademark. As explained below, Standard No. 205 requires that a manufacturer's distinctive designation appear on the glass. However, if the glass in question is marked with the prime manufacturer's DOT code mark, the designation marked on the glass may be the designation of the company that sells the glass, instead of the prime manufacturer. Section S6 of Standard No. 205 (49 CFR 571.205) sets forth the certification and marking requirements for glazing materials. Paragraphs S6.1 and S6.2 of the standard specify that each 'prime glazing material manufacturer' shall mark glazing materials manufactured by him in accordance with Section 6 of the American National Standard 'Safety Code for Glazing Materials for Glazing Motor Vehicles Operating on Land Highways,' Z-26.1 - 1977, January 26, 1977 as supplemented by Z26.1a July 3, 1980 (ANS Z-26). Paragraph S6.1 defines a 'prime glazing material manufacturer' as one who fabricates, laminates, or tempers the glazing material. Your company is therefore a 'prime glazing material manufacturer' of all glazing material that it tempers, and so you are subject to these marking requirements. One of the requirements of S6 of ANS Z-26 is that a manufacturer mark its glazing with its own 'distinctive designation or trademark.' In addition to the marking requirements of S6 of ANS Z-26, S6.1 of Standard No. 205 requires prime glazing material manufacturers to mark each piece of glazing they temper with an 'AS' number, indicating that the glazing meets all of the performance requirements set for that glazing item number. S6.2 of Standard No. 205 further requires a prime glazing manufacturer to mark each item of glazing material designed to be used in a specific vehicle with the symbol 'DOT' and a manufacturer's code mark assigned by this agency. Standard No. 205, through its incorporation of ANS Z-26, requires that all glazing be marked with a distinctive designation or trademark by the prime manufacturer. Therefore, your company cannot do what you asked to do in your letter, that is, sell glazing without any distinctive designation or trademark appearing on the glazing. However, NHTSA has previously concluded that the designation or trademark on the glazing need not be that of the prime glazing material manufacturer, if the glazing is marked with the prime manufacturer's DOT code mark. This is because NHTSA can easily and accurately identify the prime manufacturer from the DOT code mark, regardless of the distinctive designation or trademark that appears on the glazing. The agency needs to be able to identify the prime glazing material manufacturer, since that is the party responsible for any defect or noncompliance recall campaigns. When the agency can use the DOT code mark to identify the prime manufacturer, the agency does not need the distinctive designation or trademark appearing on the glazing to also identify the prime manufacturer. When a prime manufacturer sells glazing to another glazing company that sells the glazing to the public, the company selling the glazing to the public has a legitimate competitive interest in having its logo appear on that glazing. In recognition of these factors, we said in an October 16, 1986 letter to Mr. Edward T. Fennell, Jr. (copy enclosed) that Standard No. 205 permits a prime glazing material manufacturer to mark windshields with the logo of the company that was buying windshields from the prime manufacturer, with the permission of the purchasing company. Your company would be permitted to do the same for the glazing you are selling to a competitor, if your company's assigned DOT code mark appears on the glazing you are selling. If your company's assigned code mark does not appear on that glazing, or if the glazing company that is purchasing the glazing from you will not give you permission to use its logo, Standard No. 205 would require you to mark your company's distinctive designation or trademark on the glazing. Sincerely, Erika Z. Jones Chief Counsel Enclosure"; |
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ID: aiam0811OpenMr. Stan Haransky, Truck Body & Equipment Association, Inc., 5530 Wisconsin Avenue, Suite 1220, Washington, DC 20015; Mr. Stan Haransky Truck Body & Equipment Association Inc. 5530 Wisconsin Avenue Suite 1220 Washington DC 20015; Dear Mr. Haransky: This is in reply to your letter of July 20, 1972, concerning th Certification of vehicles having a dual purpose. You ask how you should determine weight ratings when a vehicle is intended to carry loads of varying weights, and cite as an example a vehicle designed to carry both gasoline and; 2 fuel oil. You indicate that you are presently placing a secon certification label on the vehicle, a copy of which you enclose, to inform the customer of the allowable weights.; The method you are using may not be consistent with the Certificatio regulations, as our position is that weight or axle values that may be confused with GAWR or GVWR cannot appear on the Certification (Part 567) label, or on adjoining labels. This will be the case if the 'total' in the 'chassis rated weight' column differs from the figure you provide on the Part 567 label for GVWR (assuming that the front and rear axle figures are identical to the GAWR figures on the Part 567 label). Gross vehicle weight rating is not necessarily the total of all axle weight ratings.; We recommend that the weight ratings be computed on the basis of th heaviest load that the vehicle is designed to carry, without attempting (for certification purposes) to anticipate the density of particular cargoes.; Yours truly, Richard B. Dyson, Assistant Chief Counsel |
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ID: aiam1703OpenMr. James P. Coughlin, Vice President - Marketing, Bell Helmets Inc., 2850 Long Beach, CA 90806; Mr. James P. Coughlin Vice President - Marketing Bell Helmets Inc. 2850 Long Beach CA 90806; Dear Mr. Coughlin: This responds to your letter of November 14, 1974, asking whether FMVS 218 applies to helmets intended for use by riders of moped cycles.; The answer to your question is yes. Standard 218 applies to 'helmet designed for use by motorcyclists and other motor vehicle users.' A 'moped' is a 'motor vehicle' (15 U.S.C. 1391), it is also a 'motorcycle,' and specifically a 'motor-driven cycle' (49 CFR 571.3). Since a motorcyclist is any rider of a motorcycle, Standard 218 clearly applies to helmets designed for use by motor driven cycle riders.; As you are probably aware, the States and their political sudivision have jurisdiction over the circumstances under which helmets must be worn. Thus a State could conceivably exclude motor-driven cycles from the coverage of its helmet use law. But this would not affect the obligation of your company to manufacture to comply with Standard 218 all helmets which you intend to be used in connection with the operation of a motor vehicle.; Yours truly, Richard B. Dyson, 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.