NHTSA Interpretation File Search
Overview
NHTSA's Chief Counsel interprets the statutes that the agency administers and the standards and regulations that it issues. Members of the public may submit requests for interpretation, and the Chief Counsel will respond with a letter of interpretation. These interpretation letters look at the particular facts presented in the question and explain the agency’s opinion on how the law applies given those facts. These letters of interpretation are guidance documents. They do not have the force and effect of law and are not meant to bind the public in any way. They are intended only to provide information to the public regarding existing requirements under the law or agency policies.
Understanding NHTSA’s Online Interpretation Files
NHTSA makes its letters of interpretation available to the public on this webpage.
An interpretation letter represents the opinion of the Chief Counsel based on the facts of individual cases at the time the letter was written. While these letters may be helpful in determining how the agency might answer a question that another person has if that question is similar to a previously considered question, do not assume that a prior interpretation will necessarily apply to your situation.
- Your facts may be sufficiently different from those presented in prior interpretations, such that the agency's answer to you might be different from the answer in the prior interpretation letter;
- Your situation may be completely new to the agency and not addressed in an existing interpretation letter;
- The agency's safety standards or regulations may have changed since the prior interpretation letter was written so that the agency's prior interpretation no longer applies; or
- Some combination of the above, or other, factors.
Searching NHTSA’s Online Interpretation Files
Before beginning a search, it’s important to understand how this online search works. Below we provide some examples of searches you can run. In some cases, the search results may include words similar to what you searched because it utilizes a fuzzy search algorithm.
Single word search
Example: car
Result: Any document containing that word.
Multiple word search
Example: car seat requirements
Result: Any document containing any of these words.
Connector word search
Example: car AND seat AND requirements
Result: Any document containing all of these words.
Note: Search operators such as AND or OR must be in all capital letters.
Phrase in double quotes
Example: "headlamp function"
Result: Any document with that phrase.
Conjunctive search
Example: functionally AND minima
Result: Any document with both of those words.
Wildcard
Example: headl*
Result: Any document with a word beginning with those letters (e.g., headlamp, headlight, headlamps).
Example: no*compl*
Result: Any document beginning with the letters “no” followed by the letters “compl” (e.g., noncompliance, non-complying).
Not
Example: headlamp NOT crash
Result: Any document containing the word “headlamp” and not the word “crash.”
Complex searches
You can combine search operators to write more targeted searches.
Note: The database does not currently support phrase searches with wildcards (e.g., “make* inoperative”).
Example: Headl* AND (supplement* OR auxiliary OR impair*)
Result: Any document containing words that are variants of “headlamp” (headlamp, headlights, etc.) and also containing a variant of “supplement” (supplement, supplemental, etc.) or “impair” (impair, impairment, etc.) or the word “auxiliary.”
Search Tool
NHTSA's Interpretation Files Search
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ID: aiam2395OpenMr. B. R. Weber, Executive Vice President, Wesbar Corporation, Box 577, West Bend, WI, 53095; Mr. B. R. Weber Executive Vice President Wesbar Corporation Box 577 West Bend WI 53095; Dear Mr. Weber: This is in reply to your letter of September 7, 1976, asking severa questions concerning paragraph S4.4.1 of Federal Motor Vehicle Safety Standard No. 108. I am sorry that we were unable to respond by September 29 as you requested. Your questions and our answers are as follows:; '1. What is the DOT specific definition and interpretation of the word 'combined optically' as they appear in paragraph S4.4.1 of DOT 108?'; In pertinent part, S4.4.1 states that 'no clearance lamp may b combined optically with any taillamp.' The phrase 'combined optically' as used here means that the luminous area of a lens used for a taillamp may not be also used as the luminous area of a lens for a clearance lamp. In other words lamps are 'combined optically' when the same luminous area of a lens is lighted for more than a single function.; '2. Can a clearance lamp and tail lamp be combined in a singl compartment with no opaque barrier wall existing between the clearance lamp bulb and the tail lamp bulb?'; The answer is no because the same luminous area of the lens would b lighted when both lamps are in use, and the lamps would be 'combined optically.'; '3. Does the DOT have no objection to a flashing red signal issuin from the side (at right angles to the fore-aft center line of the trailer) of the clearance lamp?'; Generally S4.6(b) requires most vehicle lamps to be steady burning i normal operation. If the right angle lamp serves as the rear side marker lamp, however, S4.6(b) allows it to be flashed for signaling.; '4. What is the DOT specific definition and interpretation of the ter 'clearance lamp' as it is used in DOT 108?'; The term 'clearance lamps' is defined by SAE Standard J592e incorporated by reference in Standard No. 108, and are 'lamps which show to the front or rear of a vehicle. . . to indicate the overall width and height of the vehicle.'; '5. Does the 'clearance lamp' as the words are used in DOT 108 indicat a lamp intended to serve as its major function, a back up lamp in the event of failure of the tail light filament in the combination tail, turn and stop light bulb.'; There is no intent that a clearance lamp serve as a back-up lamp in th event of a taillamp filament failure though obviously both lamps perform a marking function.; '6. If DOT approves the combination of a clearance lamp and tail lam in the same compartment, would it also approve for a boat trailer, moving the tail light outboard to show the extreme width of an over 80 foot vehicle and eliminate the need for a clearance lamp under those circumstances.'; The question is moot since a combination clearance lamp-taillamp is no permitted.; I understand that you discussed the photometric test procedure fo optically combined lamps with Mr. Owen of this agency, by telephone on September 22, 1976. So that there may be no misunderstanding I would like to set forth the test procedure in this letter. If a single lamp bulb (or filament) is used in the combined lamp, the photometrics for all of the functions must be met simultaneously. If two or more lamp bulbs (or filaments) are used and each is to provide a separate function, only those which provide that function are to be energized during the photometric test. Therefore, in a multiple compartment side marker and clearance lamp (or a multiple compartment tail and clearance lamp that is not optically combined), the clearance lamp bulb is not energized during the photometric test for the other function, and vice versa.; I hope this answers your questions. Sincerely, Frank A. Berndt, Acting Chief Counsel |
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ID: aiam0652OpenMr. Charles R. Matthews, Sr. Safety Engineer, Oshkosh Truck Corporation, P. O. Box 560, Oshkosh, WI 54501; Mr. Charles R. Matthews Sr. Safety Engineer Oshkosh Truck Corporation P. O. Box 560 Oshkosh WI 54501; Dear Mr. Matthews: In your letter of March 13 you ask for an interpretation o certification requirements applicable to remanufactured vehicles.; The National Traffic and Motor Vehicle Safety Act of 1966 and 49 CF Part 567 require only that certification of vehicle conformity be provided prior to the first purchase for purposes other than resale. On the basis of the work that you described as your 'remanufacturing', specifically that the vehicle retains its 'original frame, cab, body, axles, and transmission', we concur in your interpretation that vehicles of this nature are not new vehicles requiring certification of conformity with the Federal motor vehicle safety standards.; Yours truly, Richard B. Dyson, Assistant Chief Counsel |
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ID: aiam1940OpenMr. Heinz W. Gerth, One Mercedes Drive, Montvale, New Jersey 07645; Mr. Heinz W. Gerth One Mercedes Drive Montvale New Jersey 07645; Dear Mr. Gerth: #Please forgive the delay in responding to your lette of December 12, 1974, requesting an interpretation of the definition of 'permanently attached end fittings' appearing in Federal Motor Vehicle Safety Standard No. 106-74, *Brake Hoses*. #You have described a process of heat shrinking plastic vacuum booster hose over short corrugated metal connecting tubes, the ends of which are flared to retain threaded hex fittings. You have submitted sample hose assemblies and requested confirmation of your interpretation that the end fittings are permanently attached. While these fittings may meet the common understanding of the words 'permanently attached,' Standard No. 106-74 defines 'Permanently attached end fitting' as: #>>>an end fitting that is attached by deformation of the fitting about the hose by crimping or swaging, or an end fitting that is attached by use of a sacrificial sleeve or ferrule that requires replacement each time a hose assembly is rebuilt.<<<#Deformation of the hose about the fitting by heat shrinking is not 'deformation of the fitting about the hose by crimping or swaging.' The latter part of the definition is inapplicable because the assemblies are not subject to being rebuilt. Therefore, to classify these end fittings as permanently attached would require an amendment of the standard. Such an amendment is being considered. #Your January 7, 1975, petition for reconsideration, requesting exclusion of the above described vacuum hose from the coverage of Standard No. 106-74, was received more than 30 days after the most recent amendment of the definition of 'brake hose'. Therefore, it has been treated as a petition for rulemaking. The Standard defines 'brake hose' as: #>>>a flexible conduit manufactured for use in a brake system to transmit or contain the fluid pressure or vacuum used to apply force to a vehicle's brakes.<<<#The conduit between the vacuum booster and vacuum pump in your brake booster circuit clearly falls within this definition, and hence is subject to the Standard's requirements. The NHTSA has concluded that, because of its flexibility, this hose is exposed to the same hazards as the more traditional types of vacuum brake hose and so should be subject to the same performance requirements. Accordingly, your petition to amend the definition is denied. The conduit between the vacuum pump and the intake manifold, however, falls outside the definition of 'brake hose' because, as described by Mr. Craig Jones in a conversation with Mr. Howard Dugoff of this agency on March 17, 1975, the booster system produces full vacuum even when this conduit fails. Therefore, this conduit need not comply with the requirements of Standard No. 106-74, #Sincerely, Robert L. Carter, Associate Administrator, Motor Vehicle Programs; |
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ID: aiam0347OpenMr. George H. Jones, Executive Secretary, Louisiana Independent Tire Dealers Association., P.O. Box 2851, Birmingham, Alabama 35212; Mr. George H. Jones Executive Secretary Louisiana Independent Tire Dealers Association. P.O. Box 2851 Birmingham Alabama 35212; Dear Mr.Jones: The 'Flash Notice' that you forwarded to us on April 23, 1971, and you 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 testin 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 'du 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 th 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 mean 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 circumstances 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 motions 'certification' in such a way tha 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 for certification. Manufacturers' efforts should be directed to manufacturing tires that conform to the standard.; Your 'Flash Notice' also incorrectly explains certain provisions of th 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 subject 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 test, such as strength, normally destroy the tire.; Your statement on page 4 concerning the labeling requirements, tha 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 dimensions requirements o 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. Sincerely, Lawrence R. Schneider, Acting Chief Counsel |
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ID: aiam2680OpenMr. Jerry McNeil, American Trailers, Inc., 1500 Exchange Avenue, Box 26568, Oklahoma City, Oklahoma 73126; Mr. Jerry McNeil American Trailers Inc. 1500 Exchange Avenue Box 26568 Oklahoma City Oklahoma 73126; Dear Mr. McNeil: This responds to your July 20, 1977, letter asking whether you certification labels comply with Part 567, *Certification*, and Standard No. 120, *Tire Selection and Rims for Motor Vehicles Other Than Passenger Cars*.; As stated to you in an earlier letter, the National Highway Traffi Safety Administration does not issue approvals of compliance with Federal safety standards or regulations.The agency will, however, give you an informal opinion as to whether your labels appear to comply with the requirements. The agency has determined that the two labels that you submitted do not follow the format established in the regulations and, therefore, do not comply with the requirements. If 'R' denoted radial ply and 'F' denoted load range, the tire designation should be 10.00 R 20(F).; Sincerely, Joseph J. Levin, Jr., Chief Counsel |
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ID: aiam5145OpenMr. Dale E. Dawkins Director Vehicle Compliance and Safety Affairs Chrysler Corporation CIMS 415-03-17 1200 Chrysler Drive Highland Park MI 48288-0857; Mr. Dale E. Dawkins Director Vehicle Compliance and Safety Affairs Chrysler Corporation CIMS 415-03-17 1200 Chrysler Drive Highland Park MI 48288-0857; "Dear Mr. Dawkins: We have received your letter of March 9, 1993 responding to mine of February 18. On December 16, 1992, you informed the agency of the intent of Chrysler Corporation to manufacture 10 Chesapeake Consortium Electric Vehicles (CCEV) under NHTSA Temporary Exemption 92-1. According to your December letter, these vehicles are 'almost identical' to the TEVans for which the agency granted the temporary exemption, except that they will utilize an AC electrical motor, while the ones which were the subject of the exemption petition will be powered by a DC electrical motor. You seek no broader exemption as the combined volumes of CCEVs and TEVans 'will not exceed the maximum units of the petition that was granted.' It appeared that you wished confirmation from NHTSA that the CCEV vehicles are covered by Temporary Exemption 92-1. As I informed you on February 18, in order for the agency to provide this confirmation, we must determine that CCEV and TEVans are essentially the same vehicle and that none of the minor differences between the vehicles affects the findings made by the agency in issuing the TEVan exemption. In granting Chrysler's exemption petition covering three standards, the Administrator first found that the exemption would facilitate the development and field evaluation of a low emission motor vehicle. We do not believe that the change in electrical propulsion from DC to AC affects this finding. The Administrator next found that an exemption from the three standards would not unduly degrade the safety of the vehicle. You stated that ' b ased on our engineering judgement, there is no significant difference between the CCEV or TEVan in terms of overall vehicle safety.' While you may have used the word 'significant' in an excess of caution, it implied that there were differences between CCEV and TEVan and that there was a difference in overall vehicle safety between the CCEV and TEVan, although not an important one from Chrysler's viewpoint. Therefore, we asked you to identify the differences between the vehicles, and of the differences, if any, in the safety between the CCEVs and TEVans that may have led to Chrysler's engineering conclusion. Your letter of March 9 informs us that there are 'no discernable safety differences' between TEVans and CCEVs. It further informs us, as before, that the only difference between the two programs of electric vehicle development is the propulsion motors and transmissions. Therefore, it appears that two vehicles are essentially the same in design and in terms of the level of safety provided, and that it is appropriate to consider the CCEVs covered by the TEVan exemption. We appreciate your calling our attention to this matter. Sincerely, John Womack Acting Chief Counsel"; |
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ID: aiam3992OpenMr. Douglas I. Greenhaus, Senior Attorney/Regulatory Affairs, National Automobile Dealers Association, 8400 Westpark Drive, McLean, VA 22102; Mr. Douglas I. Greenhaus Senior Attorney/Regulatory Affairs National Automobile Dealers Association 8400 Westpark Drive McLean VA 22102; Dear Mr. Greenhaus: Thank you for your letter of July 8, 1985, to Stephen Oesch of m staff. You asked us to confirm your understanding of how our regulations would affect the alteration of a new vehicle prior to its sale.; Your question specifically relates to a situation in which a deale wants to switch, prior to sale of the vehicle, the bucket seats from one new motor vehicle to another new vehicle of the same model. You explained in a phone conversation with Mr. Oesch that changing the seats might involve some cutting and welding of the seats or their tracks. Under Part 567.7 (49 CFR Part 567.7) of our regulations, we would consider the dealer to be an 'alterer'. After completing the alteration, the dealer would be required by Part 567.7 to certify that the vehicle, as altered, complies with all applicable Federal Motor Vehicle Safety Standards. Depending on the specific design of the vehicle seat and the actual alterations performed, the replacement of a seat would be affected by Federal Motor Vehicle Safety Standard No. 207, *Seating Systems*, and could be affected by Standard No. 208, *Occupant Crash Protection*, and Standard No. 210, *Seat Belt Assembly Anchorages*.; Thank you for providing us with the information on glass tinting. hope this information on vehicle alteration is of assistance to you. If you have further questions, please let me know.; Sincerely, Jeffrey R. Miller, Chief Counsel |
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ID: aiam0717OpenMr. Harry Fund, Executive Vice-President, Labelmaster, 2447 W. Roosevelt Road, Chicago, Illinois 60608; Mr. Harry Fund Executive Vice-President Labelmaster 2447 W. Roosevelt Road Chicago Illinois 60608; Dear Mr. Fund: This is in response to your letter of May 11, 1972, submitting sampl labels for retreaded tires, the samples which you submit, with the appropriate information properly filled in or clearly indicated by an 'X' or other mark, will meet the requirements of S6.2 and S6.3 of Standard No. 117.; Sincerely, Richard B. Dyson, Assistant Chief Counsel |
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ID: aiam1805OpenMr. Charles J. Calvin, President, Truck Trailer Manufacturers Association, 2430 Pennsylvania Avenue, N.W., Washington, DC 20037; Mr. Charles J. Calvin President Truck Trailer Manufacturers Association 2430 Pennsylvania Avenue N.W. Washington DC 20037; Dear Mr. Calvin: It has come to the attention of the National Highway Traffic Safet Administration that a 'recommended Practice' issued by the Truck Trailer Manufacturers Association, titled 'Method for Determining GAWR and GVWR for Truck Trailer Certification' may be misleading some trailer manufacturers in their responsibilities to certify their products to Standard No. 121, *Air brake systems*. The recommended practice was reviewed by the NHTSA in draft form to determine its consistency with Parts 567, *Certification*, and 568, *Multi-stage vehicle manufacture*, of Title 49 of the Code of Federal Regulations.; The NHTSA in a March 30, 1972, letter to Mr. Vincent Grey found th draft consistent with Parts 567 and 568. The draft discusses, among other things, the method for determining the gross axle weight rating (GAWR) of an axle at a speed lower than full highway speed. It appears, however, that some manufacturers have understood the draft's discussion to set out the entirety of their responsibilities under the safety standards, and in particular, Standard No. 121. Although the March 30, 1972, review of the TTMA procedures did approve the use of speed qualifications in establishing GAWR and GVWR on Certification labels, our review only recognized the possibility that in some cases GAWR and GVWR might be properly established on the basis of a speed limitation. (An example of such a possibility would be for a vehicle which was physically incapable of reaching highway speeds.); We do not consider it reasonable to extend that interpretation t permit a manufacturer to establish a reduced- speed rating to avoid a safety standard such as Standard No. 121. A vehicle capable of highway speeds and reasonably expected to be operated at such speeds is subject to Standard No. 121 at weight ratings specified for highway speeds.; In view of the misunderstanding that has arisen, we believe i necessary to clarify our approval letter of March 30, 1973, insofar as it relates to the establishment of GAWR and GVWR. These values, to meet the requirements of SS567.4(g)(3) and (4), must henceforth be unqualified ratings, and may not be based on reduced speeds. If reduced-speed ratings are to be established, they must be *in addition to* the unqualified ratings, and must appear at the end of the certification label, or on a separate label, and in either case be accompanied by an adequate explanation as to the scope of their use.; We realize that this clarification may force revision of the practice of some of your members. Manufacturers who have utilized this practice should be advised immediately that it is inappropriate under the requirements.; Yours truly, James C. Schultz, Chief Counsel |
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ID: aiam3838OpenMr. Christopher Moore, Intec, 23132 La Cadena, Laguna Hills, CA 92653; Mr. Christopher Moore Intec 23132 La Cadena Laguna Hills CA 92653; Dear Mr. Moore: This responds to your April 24, 1984 letter regarding the installatio of a closed circuit television viewing system in new vehicles, as an alternative to rearview mirror systems. The television system provides a view of the area behind the vehicle from a monitor screen placed on or near the dash.; As you note in your letter, Federal Motor Vehicle Safety Standard 11 specifies the use of rearview mirrors to provide improved rearward and side visibility in new motor vehicles. No provision is made for alternative means of compliance such as closed circuit television systems, so such alternative systems are not authorized. However, the closed circuit system could be used as a supplement to a mirror system which meets the requirements of Standard 111.; The only options available to a vehicle manufacturer seeking to use closed circuit system as a replacement for the required mirror system would be to file a petition to amend the standard or a petition for an exemption from the standard. Requirements applicable to these petitions are set forth in Title 49 of the Code of Federal Regulations, Parts 552 and 555, respectively,. These petitions are only granted in the limited circumstances set forth in those regulations.; If you have further questions on this matter, please contact us. Sincerely, Frank Berndt, 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.