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: aiam2590OpenMr. Richard L. Kreutziger, Executive Vice President, Coach & Equipment Sales Corp., Post Office Box 36, Penn Yan, NY 14527; Mr. Richard L. Kreutziger Executive Vice President Coach & Equipment Sales Corp. Post Office Box 36 Penn Yan NY 14527; Dear Mr. Kreutziger: This responds to your May 6, 1977, letter asking what standards appl to vehicles designed to transport fewer than 10 passengers to or from school.; Vehicles that transport fewer than 10 passengers to or from school ar not considered buses according to the National Highway Traffic Safety Administration's (NHTSA) definition of 'bus' found in 49 CFR Part 571.3. Accordingly, these vehicles transporting fewer than 10 passengers would not need to comply standards (sic) applicable to either school buses or buses in general. The vehicles to which you refer would be required to comply with standards applicable to passenger cars or multipurpose passenger vehicles depending upon the type of vehicle being used to transport children. You should consult Part 571.3 (enclosed) of our regulations to determine the classification of the vehicle you intend to construct since the vehicle classification establishes the applicability of the standards.; Sincerely, Joseph J. Levin, Jr., Chief Counsel |
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ID: aiam5255OpenMr. Greg Biba 172820 Highway QQ #8 Waupaca, WI 54981; Mr. Greg Biba 172820 Highway QQ #8 Waupaca WI 54981; "Dear Mr. Biba: This responds to your letter asking about safet regulations for a device you would like to sell. The device is an 'infant observation mirror' that would allow parents to see their baby's face when the infant restraint is installed in the rear seat of a vehicle. The mirror is on a stand that sits under the infant restraint. By way of background information, 103 of the National Traffic and Motor Vehicle Safety Act ('Safety Act,' 15 U.S.C. 1392) authorizes the National Highway Traffic Safety Administration (NHTSA) to issue safety standards for new motor vehicles and new items of motor vehicle equipment. NHTSA does not, however, approve or certify any vehicles or items of equipment. Instead, the Safety Act establishes a 'self-certification' process under which each manufacturer is responsible for certifying that its products meet all applicable safety standards. The agency periodically tests vehicles and items of equipment for compliance with the standards. In response to your question, there is currently no Federal motor vehicle safety standard (FMVSS) that directly applies to the product you wish to manufacture. Under the authority of the Safety Act, NHTSA has issued Standard No. 213, Child Restraint Systems, which specifies requirements for child restraint systems used in motor vehicles and aircraft. However, Standard No. 213 applies only to new child restraint systems and not to aftermarket components of a child restraint system, such as an observation mirror. I note, however, that there are other Federal laws that indirectly affect your manufacture and sale of the device. Under the Safety Act, your product is considered to be an item of motor vehicle equipment. As a manufacturer of motor vehicle equipment, you are subject to the requirements in 151-159 of the Safety Act concerning the recall and remedy of products with safety related defects. I have enclosed an information sheet that briefly describes those responsibilities. In the event that you or NHTSA determines that your mirror 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, manufacturers, distributors, dealers, and motor vehicle repair businesses are subject to 108(a)(2)(A) of the Safety Act, which states: '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 ....' It appears unlikely from the nature of your product that it would be placed in vehicles by commercial businesses instead of child restraint owners. However, if your product were to be installed by persons in those categories, they should ensure that its installation does not compromise the safety protection provided by a child restraint system. The prohibition of 108(a)(2)(A) does not apply to the actions of vehicle owners in adding to or otherwise modifying their vehicles or items of motor vehicle equipment. The 'render inoperative' prohibition of 108(a)(2)(A) does not apply to the actions of vehicle owners in adding to or otherwise modifying their vehicles or items of motor vehicle equipment. However, NHTSA urges owners not to undertake modifications that would reduce the efficacy of any safety device or element of design. We note that an observation mirror could be struck by an infant in a crash, such as during the 'rebound' phase of a frontal impact. In the interest of safety, we suggest you manufacture your mirror so that the risk of head injuries in a crash is minimized. I hope this information is helpful. If you have further questions, please contact Deirdre Fujita of my staff at (202) 366-2992. Sincerely, John Womack Acting Chief Counsel"; |
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ID: aiam4852OpenMr. Earl C. Lempke President, Delavan Industries, Inc. 1728 Walden Avenue Buffalo, NY 14225; Mr. Earl C. Lempke President Delavan Industries Inc. 1728 Walden Avenue Buffalo NY 14225; "Dear Mr. Lempke: This responds to your letter of March 6, l991, t Taylor Vinson of this Office. You have asked whether there is 'any Federal ruling stating that Trailer Clearance Lights are considered as Safety Equipment and as such are not be be included as part of the overall width of the vehicle.' You have enclosed a copy of 49 CFR 323.20, the clearance lamp regulation of the Federal Highway Administration (FHWA), with the observation that 'this section does not answer the question.' I am pleased to clarify this situation for you. As the FHWA regulation states, 'Clearance lamps shall be mounted so as to indicate the extreme width of the motor vehicle . . . .' This requirement is virtually identical to that in Table II of this agency's Federal Motor Vehicle Safety Standard No. 108 that clearance lamps be located 'to indicate the overall width of the vehicle . . . .' In l976, NHTSA issued an interpretation that was published in the Federal Register on August 23 of that year stating that 'The term 'overall width' refers to the nominal design dimension of the widest part of the vehicle, exclusive of . . . marker lamps' such as clearance lamps. I enclose a copy for your information. The FHWA concurs with this interpretation, and has provided us with some additional comments. Federal width limits apply only on the National Network highways (23 CFR 658, Section A). The width of commercial trailers operated on these highways is to be measured across the sidemost load carrying structures, support members, and structural fasteners, as stated in an interpretation published on March 13, l987, a copy of which I enclose. That proceeding also determined that side marker lamps and any other 'non load-carrying safety appurtenance' which extended beyond these limits were excluded from width measurements. This would include clearance lamps, and thus exclude them also from width measurements. In December 1989, FHWA issued an advance notice of proposed rulemaking to consider if a new approach should be adopted to determine which devices to exclude from measurements of vehicle length and width. I also enclose a copy of that notice. FHWA advises that its next notice on the subject should be issued soon. Although under FHWA regulations, the States determine whether safety equipment is to be excluded from the measurement of vehicle width, we believe that the State determination must be identical to the NHTSA position. Federal law (l5 U.S.C. 1392(d)) prohibits a State from enacting or maintaining in effect any regulation covering the same aspect of performance as a Federal motor vehicle safety standard unless it is identical to the Federal requirement. We believe that a State must also interpret an identical regulation in a manner identical to NHTSA's interpretation. Sincerely, Paul Jackson Rice Chief Counsel Enclosure"; |
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ID: aiam2085OpenMr. C.D. McCarty, the B.F. Goodrich Company, 500 South Main Street, Akron, Ohio 44318; Mr. C.D. McCarty the B.F. Goodrich Company 500 South Main Street Akron Ohio 44318; Dear Mr. McCarty: This is in response to your August 30, 1975, letter concerning th Federal Motor Vehicle Safety Standards applicable to tires which the manufacturer expects to be used on both passenger cars and trailers.; >>>S2. of Standard No. 109 specifies: This standard applies to new pneumatic tires for use on passenger car manufactured after 1948...; Similarly, S3. of Standard No. 119 specifies: This standard applies to new pneumatic tires designed for highway us on multipurpose passenger vehicles, trucks, buses, *trailers* and motorcycles manufactured after 1948... (emphasis added)<<<; These standards are mutually exclusive. Therefore, dual marking indicating compliance with the performance requirements of each are not permitted. A tire whose predominant contemplated use is in passenger cars is subject to Standard No. 109, even if the manufacturer knows it will also be marketed as a trailer tire. The choice of standard to which the tire will be certified should be made by the manufacturer. The NHTSA will accept a manufacturer's good faith determination of the applicable standard. You should note that if the tire is certified as conforming with Standard No. 119, its use as original equipment on passenger cars is prohibited by Standard No. 110. (The proposed Standard No. 120, however, would permit the use of passenger car tires on vehicles other than passenger cars, subject to a 10 percent load rating correction factor.); Please note further that a tire which is subject to Standard No. 10 must be of a size designation listed in Appendix A of that standard. Conversely, any tire labeled with a size designation which is listed in that appendix is subject to Standard No. 109.; The final paragraph of your letter discussed 'certain types and classe of equipment [determined by the NHTSA to be] non-trailers by definition.' You appear to be referring to vehicles which are not 'trailers' because they are not 'motor vehicles' or items of 'motor vehicle equipment' as the latter terms are defined by the National Traffic and Motor Vehicle Safety Act of 1966, as amended. No Federal Motor Vehicle Safety Standards apply to units which are neither motor vehicles nor motor vehicle equipment. The manufacturers of such unit may equip them with tires of their choice.; Sincerely, Frank A. Berndt, Acting Chief Counsel |
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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 |
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.