
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: nht71-3.45OpenDATE: 07/21/71 FROM: AUTHOR UNAVAILABLE; E. T. Driver; NHTSA TO: Rueck and Company TITLE: FMVSS INTERPRETATION TEXT: This is in reply to your letter of July 7, 1971, to the National Highway Safety Bureau (now the National Highway Traffic Safety Administration) concerning the requirements for sealed beam headlamp units. The answers to your specific questions are as follows: 1. Sealed beam units must meet the photometric specifications in SAE J579 at the design voltage at or below the maximum amperes specified in SAE J573. 2. Tolerances are as follows: Electrical power - the maximum electrical power is the product, in watts, of the design voltage multiplied by the maximum amperes at design volts. There is no specified minimum electrical power. Maximum amperes - There is no tolerance. Maximum amperes is the maximum specified in SAE J573. Design watts - There is no tolerance. There is, however, a tolerance on the actual watts or electrical power as described above. 3.4.4. The filament types and positions are illustrative of current practice only. Any type or position may be used to meet the specification of J579 and J573. 5. All glass sealed beam units are not mandatory. There are no restriction in Federal Motor Vehicle Safety Standard No. 108 or the SAE Standards on the number of pieces or the materials which are used to complete the assembled sealed beam unit as long as the specifications, including those in SAE J571, are met. Caution should be used, however, to ensure that a good and durable seal is obtained between the metal back, if used, and the other parts to optimize the useful service life of the sealed beam unit.
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ID: nht71-3.46OpenDATE: 07/21/71 FROM: AUTHOR UNAVAILABLE; Lawrence R. Schneider; NHTSA TO: Recreational Vehicle Institute, Inc. TITLE: FMVSS INTERPRETATION TEXT: This is in reply to your letter of June 22, 1971, enclosing a copy of Mr. Shrake's memorandum "Seat Belts Required by July 1, 1971", copy attached. We concur in your conclusion that the seat belt requirement does not apply to chassis-cabs, cabs, and vans, manufactured before July 1, 1971, and that, on or subsequent to that date, are completed as, or modified to become, motor homes. We concur also with the other points set out in the memorandum. ENCLOSURE |
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ID: nht71-3.47OpenDATE: 07/21/71 FROM: AUTHOR UNAVAILABLE; Lawrence R. Schneider; NHTSA TO: Erie Strayer Company TITLE: FMVSR INTERPRETATION TEXT: This is in reply to your letter of June 15, 1971, inquiring if a mobile concrete batch plant is considered a motor vehicle for purposes of the Tire Identification and Record Keeping Regulation (49 CFR 574). The Erie Strayer's Mobile Combo-100 illustrated in your enclosed brochure is considered a motor vehicle. Enclosed is a letter dated April 20, 1970, signed by Secretary Volpe which sets forth the reasoning behind this determination. As a motor vehicle manufacturer, you are required under Part 574, to maintain records of the name and address of the first purchaser for purposes other than resale of your vehicle along with a record of the tires shipped on or in your vehicles. If we can be of further assistance, please feel free to write. ENC. |
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ID: nht71-3.48OpenDATE: 07/22/71 FROM: AUTHOR UNAVAILABLE; E. T. Driver; NHTSA TO: S. Jackson-Smith TITLE: FMVSS INTERPRETATION TEXT: This is in reply to your recent letter inquiring about the mounting of a spare tire between headlights of a Volkswagen Camper. There is no Federal regulation that prohibits the mounting of the spare tire on the front of a vehicle. Federal motor vehicle safety standards apply to new vehicles and regulate manufacturers so as to assure compliance with applicable requirements. The standards do not regulate the vehicle purchaser and owner. However, in the importation of vehicles into the United States, certain requirements must be met. These requirements are described in the enclosed pamphlet dated October 1969. If your vehicle has been manufactured more recently, up-to-date requirements may be obtained from your Volkswagen dealer. It is recommended that inquiry be made of the State in which the vehicle will be licensed or driven for applicable laws and regulations in this area. We appreciate your concern for motor vehicle safety. ENC. |
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ID: nht71-3.49OpenDATE: 07/22/71 FROM: AUTHOR UNAVAILABLE; Lawrence R. Schneider; NHTSA TO: Recreational Vehicle Institute TITLE: FMVSS INTERPRETATION TEXT: By letter of May 26, 1971, you requested our interpretation of S7.2.3 of Standard No. 208, Occupant Crash Protection, as it affects motor homes and campers that have a forward control configuration. The section provides that forward control vehicles under 10,000 pounds GVWR manufactured after August 15, 1977, may continue to use seat belt assemblies and used not provide passive protection, but that motor homes and vehicles carrying chassis-mount campers must provide passive protection, at least in head-on impacts. Your question is whether a motor home or chassis-mount camper that is also a forward control vehicle must provide passive protection. The exemption granted by S7.2.3 to forward control vehicles was based on the difficulties inherent in providing adequate passive protection for(Illegible Word) vehicles, regardless of their anticipated use. If a forward control vehicle is manufactured in the form of a motor home or camper, the exemption continues to apply and such a vehicle would not be required to conform to the passive protection requirements of S4.1.2.2. Please advise us if you have further questions on this subject. |
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ID: nht71-3.5OpenDATE: 05/20/71 FROM: AUTHOR UNAVAILABLE; R. B. Dyson for L. R. Schneider; NHTSA TO: Boise Cascade Corporation TITLE: FMVSS INTERPRETATION TEXT: This is in reply to your letter of April 29, to Mr. Charles West, on the subject of air brake systems on mobile structure trailers. The standard to which you refer does not require air brakes to be installed on trailers, as your associates seem to fear. However, if your company decides on its own initiative to install air brakes on its mobile structure trailers, such brakes must conform to the air brake standard if the trailer is built on or after the effective date of the standard, January 1, 1973. Please advise us if further clarification is needed. |
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ID: nht71-3.50OpenDATE: 07/27/71 FROM: AUTHOR UNAVAILABLE; E. T. Driver; NHTSA TO: Ichikoh Industries, Ltd. TITLE: FMVSS INTERPRETATION TEXT: This is in response to your inquiry of July 16, 1971, concerning supplemental mirrors. Federal Motor Vehicle Safety Standard No. 111 does not prohibit the installation of a supplemental outside mirror on the passenger's side. The Standard does stipulate certain field of view requirements for both the inside and driver's outside mirror, but the manufacturer is certainly free to exceed these field of view requirements with additional mirrors. |
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ID: nht71-3.6OpenDATE: 05/21/71 FROM: AUTHOR UNAVAILABLE; Lawrence R. Schneider; NHTSA TO: Louisiana Independent Tire Dealers Association TITLE: FMVSS INTERPRETATION TEXT: The "Flash Notice" that you forwarded to us on April 23, 1971, and your telephone conversation of May 10 with Mike Peskoe of my staff have raised certain questions concerning your interpretation of Motor Vehicle Safety Standard No. 117, "Retreaded Pneumatic Tires." On page 1 of the "Flash Notice" you state, "But, so far as testing goes, it's apparent the risk for retreaders not to do their own testing to prove compliance is substantially greater than anticipated." You proceed to discuss whether manufacturers should test their own tires in order to prove "due care." As part of this discussion you refer to the statement in the preamble in the Notice of March 5, 1970, concerning what could suffice for a valid certification, and state that we have told you that this preamble is "still basically valid." There is evidently some confusion as to the purpose and meaning of "due care" under the National Traffic and Motor Vehicle Safety Act, and also as to the difference between compliance and certification. A manufacturer of a retreaded tire that did not comply with the standard but who used due care in manufacturing the tire to comply with the standard cannot be subject to a civil penalty. The answer to your hypothetical question on page 3, "What if due care is used, but the tire doesn't comply" is that the manufacturer cannot be subject to a civil penalty in this situation. (He may, however, be required to send defect notification letters and be urged to recall.) We do not agree that one is "guilty until proven innocent." A finding of noncompliance must first be made by the agency. Once the agency, through testing or otherwise, discovers a noncompliance, it is then up to the manufacturer to show that he exercised due care. Although the issue of due care is one that is ultimately decided by a court, the agency, in determining whether to seek a civil penalty, will make a preliminary determination on this issue. You asked in your conversation of May 10 that we amplify what is meant by "due care." "Due care" is a legal concept embodying the care that would be exercised by a reasonable man under the circumstances, and the circumstances of each situation must be considered in determining whether due care has been exercised. The set of cirumstances set forth in the preamble of March 5, 1970, might constitute "due care" in a large number of situations. To be sure, a manufacturer who tests his own tires might be considered in some cases to have exercised more care to insure that his tires complied with the standard than one who relied on tests by a third person on other tires that were similarly manufactured. Each potential case would be considered, and decided, by the agency on the facts peculiar to it. The "Flash Notice" also mentions "certification" in such a way that clarification of the term is indicated. First, all tires manufactured after the standard's effective date must be certified. Certification is accomplished, as you know, by placing the symbol "DOT" on the tire in a prescribed location. In practice, all tires will have the symbol "DOT" affixed to them after January 1, 1972, as manufacturers could not manufacture these tires without placing the mark on them. The answer to your question on page 3, "What if one certified does not comply" is that even if the tire fails to comply, if the manufacturer has exercised due care, in the view of the court, in manufacturing the tires to comply to the standard, his certification will not be considered "false or misleading," and no civil penalty can be imposed. The same "due care" that will suffice for compliance will suffice for purposes of certification. Manufacturers' efforts should be directed to manufacturing tires that conform to the standard. Your "Flash Notice" also incorrectly explains certain provisions of the standard. First, with reference to which tests a particular tire must pass, S5.1.1 requires each tire to be able to pass every test, but when a single tire, during the agency testing, is subjected to one of the groups of tests specified in S5.1.1, that particular tire will not be tested further. As indicated to you on the phone, this is similar to the test procedure of Standard No. 109. It merely reflects that fact that certain tests, such as strength, normally destroy the tire. Your statement on page 4 concerning the labeling requirements, that retreaders can "buff off the labeling required in retreading without worry, since it is displayed in other areas," is unclear to us. The standard requires each item of information required by Standard No. 109 to be retained in at least one location (Standard No. 109 requires each item to be on both sidewalls) on the complete retreaded tire. Retreaders must therefore take care that each tire retains the original marking to this extent. Finally, with reference to the physical dimension requirements of S5.1.2, the 10 percent tolerance refers only to the maximum dimension with respect to the section width specified in the tables of Standard No. 109. Your reference on page 4 to "10% under" is incorrect, since no minimum measurement is stated in the standard. However, the section width is a variable in computing the size factor which must be at least the minimum specified for the tire in the tables in the Appendix. If you have further questions, please let us know. |
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ID: nht71-3.7OpenDATE: 05/24/71 FROM: AUTHOR UNAVAILABLE; Lawrence R. Schneider; NHTSA TO: Ford Motor Company TITLE: FMVSS INTERPRETATION TEXT: This is in reply to your letter of May 7, 1971, requesting clarification of S4.9 of Motor Vehicle Safety Standard No. 213, "Child Seating Systems." Your letter asks whether the release mechanism requirements of S4.9 apply to either a Type 1 or Type 2 seat belt assembly that is used to restrain the child seating system pursuant to S4.4(b) of the standard. Your letter also raises by implication the question whether a Type 1 or Type 2 seat belt assembly that pursuant to S4.9, is used to directly restrain the child must also meet the release mechanism requirements of S4.9. The answer to both questions is no. The release mechnism requirements that each Type 1 or Type 2 seat belt assembly is required to meet are those specified in Motor Vehicle Safety Standard No. 209. The requirements for the release mechanism specified in S4.9 of Standard No. 213 apply to those components, other than a Type 1 or Type 2 seat belt assembly, that directly restrain the child. |
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ID: nht71-3.8OpenDATE: 05/25/71 FROM: AUTHOR UNAVAILABLE; Lawrence R. Schneider; NHTSA TO: Distributers Association TITLE: FMVSR INTERPRETATION TEXT: This is response to your letter of May 12, 1971, in which you inquired about the responsibilities, under Parts 567 and 568 of the NHTSA regulations, of a company that sells small trailer chassis in kit form, to persons who assemble them, add bodies, and sell them to users. You discussed the questions by telephone with Richard Dyson of this office on May 21, and this letter confirms the answers that Mr. Dyson gave you then. Since the unit sold by the company in question is not assembled, it is not an "incomplete vehicle" within the meaning of Part 568, and the company therefore has no responsibilities under that part to provide information to subsequent purchasers. The person who assembles the kit and adds a body is, of course, a manufacturer, and must certify the complete vehicle under @ 567.4 of the Certification regulations. It appears that this certifier would normally rely on the chassis kit seller to provide the basic information concerning the vehicle characteristics, and the assurance that when assembled according to instructions it will conform to applicable motor vehicle safety standards, so that he can responsibly certify the vehicle. We assume that the chassis kit seller would provide this information as a commerical responsibility, although the relationship is not at present governed by NHTSA regulations. Please let us know if we can be of further assistance. |
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.