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: aiam0946OpenMr. F. S. Murley, Administrative Engineer, Oshkosh Truck Corporation, Post Office Box 560, Oshkosh, WI 54901; Mr. F. S. Murley Administrative Engineer Oshkosh Truck Corporation Post Office Box 560 Oshkosh WI 54901; Dear Mr. Murley: This is in reply to your letter of January 4, 1973, in which you as for our confirmation of your interpretation of Part 567 and Part 568 of Title 49 of the Code of Federal Regulations that would place the responsibility for certification on the user in those instances where he is the final-stage manufacturer.; Paragraph 567.5 of Title 49 of the Code of Federal Regulations Requirements for Manufacturers of Vehicles Manufactured in Two or More Stages, specifies that '. . . each final-stage manufacturer, . . . of a vehicle manufactured in two or more stages shall affix to each vehicle a label . . . .' Therefore, end users who are also manufacturers would be required to affix the label.; If you have further questions, we will be pleased to answer them. Sincerely, Francis Armstrong, Director, Office of Standard Enforcement, Motor Vehicle Programs; |
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ID: aiam0947OpenMr. F. S. Murley, Administrative Engineer, Oshkosh Truck Corporation, Post Office Box 560, Oshkosh, WI 54901; Mr. F. S. Murley Administrative Engineer Oshkosh Truck Corporation Post Office Box 560 Oshkosh WI 54901; Dear Mr. Murley: This is in reply to your letter of January 4, 1973, in which you as for our confirmation of your interpretation of Part 567 and Part 568 of Title 49 of the Code of Federal Regulations that would place the responsibility for certification on the user in those instances where he is the final-stage manufacturer.; Paragraph 567.5 of Title 49 of the Code of Federal Regulations Requirements for Manufacturers of Vehicles Manufactured in Two or More Stages, specifies that '. . . each final-stage manufacturer, . . . of a vehicle manufactured in two or more stages shall affix to each vehicle a label . . . .' Therefore, end users who are also manufacturers would be required to affix the label.; If you have further questions, we will be pleased to answer them. Sincerely, Francis Armstrong, Director, Office of Standard Enforcement, Motor Vehicle Programs; |
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ID: aiam0862OpenMr. J. Richard Schlen, Schlen Body and Equipment Co., P. O. Box No. 229, Carllnville(sic), IL 62626; Mr. J. Richard Schlen Schlen Body and Equipment Co. P. O. Box No. 229 Carllnville(sic) IL 62626; Dear Mr. Schlen: This is in reply to your letter of September 22 to Mr. Ed Leysath o this Office regarding interpretations of FMVSS No. 108 on required mounting of marker lights on your dump trailers.; In answer to your first problem, a combination front clearance and sid marker lamp must meet the requirements for both, therefore, the full 180-degree visibility is required. If you determine that it is not practicable to mount the combination lamp in your alternate location, because of a greater possibility of damage, then separate lamps should be considered.; In answer to your second problem, because of the configuration and en use of your dump semi-trailers, your interpretation that rear clearance lamps mounted in a light box just below the rear trailer crossmember are as high as practicable is correct.; Sincerely, E. T. Driver, Director, Office of Operating Systems, Moto Vehicle Programs; |
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ID: aiam0976OpenMr. F. S. Murley, Administrative Engineer, Oshkosh Truck Corporation, Post Office Box 560, Oshkosh, WI 54901; Mr. F. S. Murley Administrative Engineer Oshkosh Truck Corporation Post Office Box 560 Oshkosh WI 54901; Dear Mr. Murley: This is in reply to your letter of January 4, 1973, in which you as for our confirmation of your interpretation of Part 567 and Part 568 of Title 49 of the Code of Federal Regulations that would place the responsibility for certification on the user in those instances where he is the final-stage manufacturer.; Paragraph 567.5 of Title 49 of the Code of Federal Regulations Requirements for Manufacturers of Vehicles Manufactured in Two or More Stages, specifies that '. . . each final-stage manufacturer, . . . of a vehicle manufactured in two or more stages shall affix to each vehicle a label . . . .' Therefore, end users who are also manufacturers would be required to affix the label.; If you have further questions, we will be pleased to answer them. Sincerely, Francis Armstrong, Director, Office of Standard Enforcement, Motor Vehicle Programs; |
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ID: aiam5507OpenMr. Ralph T. Welch 840 SE Summit Drive Roseburg, OR 97470; Mr. Ralph T. Welch 840 SE Summit Drive Roseburg OR 97470; Dear Mr. Welch: This responds to your request for an interpretatio whether the Federal Motor Vehicle Safety Standards (FMVSS) specify 'the type of odometer' placed in a motor vehicle. As explained below, the FMVSS do not so specify. If an odometer is provided, its mileage may be stated in kilometers. Standard No. 101, Controls and displays, specifies requirements for the location, identification, and illumination of motor vehicle controls and displays. Neither Standard No. 101 nor any other FMVSS specifies that an odometer be placed in a motor vehicle or that it register distance in miles, rather than kilometers. However, S5.3.1 (referencing Table 2 'Identification and Illumination of Displays') of Standard No. 101, specifies that if an odometer is provided and the odometer measures mileage in kilometers, the mileage must be stated as 'KILOMETERS' or 'km.' I hope this information is helpful. If you have any further questions, please contact Dorothy Nakama of my staff at (202) 366-2992. Sincerely, Philip R. Recht Chief Counsel; |
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ID: aiam0339OpenMarion C. Denton, Marden Manufacturing Company, 205 Denton Avenue, Auburndale, FL 33823; Marion C. Denton Marden Manufacturing Company 205 Denton Avenue Auburndale FL 33823; Dear Mr. Denton: This is in reply to your letter of May 3, 1971, requesting a interpretation of the Tire Identification and Record Keeping Regulation. You indicated in your letter that you are a trailer manufacturer. As such, you are considered a motor vehicle manufacturer under both the regulation and section 102(3) and (5) of the National Traffic and Motor Vehicle Safety Act of 1966 (15 U.S.C. 1381 *et seq*.) (copies enclosed).; As a manufacturer, you are required, by section 113(f) of the Act, t record the name and address of the first purchaser for purposes other than resale. Section 574.10 of the regulation requires that you maintain a record of the tires shipped on or in vehicles which you manufacture. In the event of a defect notification concerning either the vehicle or its tires, your responsibilities are enumerated in section 111 and 113 of the Act.; Sincerely, Lawrence R. Schneider, Acting Chief Counsel |
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ID: aiam2056OpenMr. Ben Perchik, 1520 Dawn Drive, Louisville, Kentucky 40216; Mr. Ben Perchik 1520 Dawn Drive Louisville Kentucky 40216; Dera(sic) Mr. Perchik: #This is in response to your letter of July 29 1975, concerning tire identification markings, received by this agency on August 29, 1975. #I have attached two diagrams that illustrate the meaning of the tire code markings on new and retreaded tires. Immediately following 'DOT' is a two- or three-letter code (marked in red on the diagram) that indicates the manufacturer or retreader of the tire. I have also attached a list of the tire manufacturers and retreaders using each code. Following the manufacturer's code are two numbers representing the tire size (marked in blue on the diagram). Next, some tires will have three letters or numbers which represent an optional tire type code mainly of use to the manufacturer (marked in yellow on the diagram). The last three numbers represent the date of manufacture (marked in green on the diagram). #I hope this information proved useful to you. #Yours truly, Richard B. Dyson, Assistant Chief Counsel; |
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ID: aiam2190OpenMr. F. A. McNiel, 611 Bouldin Avenue, Austin, TX, 78704; Mr. F. A. McNiel 611 Bouldin Avenue Austin TX 78704; Dear Mr. McNiel: This is in reply to your petition of November 7, 1975, 'for th correction of subsection S4.5.4 and S4.6(b) as set forth by existing Federal Motor Vehicle Safety Standard No. 108.'; It is your opinion that S4.5.4, which requires activation of stop lamp upon application of the service brakes, is design restrictive, and 'leaves no opportunity for innovation by the private sector for other solutions for the activation of a motor vehicle's stoplamps' (sic). You have suggested that S4.5.4 be amended to include at its end 'or by other beneficial means which will not impair the lighting system or the mechanical functioning of the vehicle'.; Any performance standard is design restrictive to some extent, it mus restrict manufacturers to designs that meet the desired performance requirements. Its validity as a performance standard depends on whether the restrictions of the standard are only as narrow as reasonably necessary to achieve the desired safety performance. In this case we have found that the requirement meets this test. A signal to other drivers that the service brakes are being applied is precisely the performance being sought in S4.5.4. A signal based on some other condition (e.g., vehicle deceleration) might not be as timely, or might fail altogether to operate at the critical moment (as where it is based on lifting the accelerator pedal). Since the requirement is limited to the desired safety performance, we find it valid, and your petition in this area is denied.; You also ask for an amendment of S4.6(b) to include 'rear lamps' amon those that may be flashed for signalling purposes, since you believe that conventional wiring circuits presently allow these lamps to be flashed when headlamps are flashed. When the headlamps are flashed by means of the on-off switch, it is true that rear lamps will flash. But that type of flashing is in no way restricted by the standard. The flashing intended to be regulated by S4.6(b) is by automatic means (see S3 definitions) and, except for rear turn signal lamps, these automatic devices would not be connected to rear lamp circuits. Thus, there appears to be no need for the amendment you suggest and your petition is accordingly denied.; We appreciate your continuing efforts on behalf of traffic safety. Sincerely, Robert L. Carter, Associate Administrator, Motor Vehicl Programs; |
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ID: aiam2520OpenMr. H. Miyazawa, Director, Automotive Lighting, Engineering Department, Stanley Electric Co., Ltd., 2-9-13 Nakameguro, Meguro-Ku, Tokyo 153, Japan; Mr. H. Miyazawa Director Automotive Lighting Engineering Department Stanley Electric Co. Ltd. 2-9-13 Nakameguro Meguro-Ku Tokyo 153 Japan; Dear Mr. Miyazawa: This is in reply to your letter of February 14, 1977, concerning th symbol 'DOT' as a certification of compliance to FMVSS No. 108.; The symbol 'DOT' is permitted by the Standard to be placed on the ite of equipment in lieu of the certification requirements of Section 114 of the 'National Traffic and Motor Vehicle Safety Act of 1966,' which states, in part '...In the case of an item of motor vehicle equipment such certification may be in the form of a label or tag on such item or on the outside of a container in which such item is delivered...'; 'DOT' on the individual container does not meet the certificatio requirements. The label or tag must state that the item 'conforms to all applicable Federal motor vehicle safety standards.'; Sincerely, E. T. Driver, Director, Office of Crash Avoidance, Moto Vehicle Programs; |
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ID: aiam1491OpenMr. Keigo Ohgiya, Executive Director, The Japan Automobile Tire Manufacturers' Association, Inc., 9th Floor, Toranomon Building, No. 15, Shiba Toranomon, Minato-Ku, Tokyo, Japan; Mr. Keigo Ohgiya Executive Director The Japan Automobile Tire Manufacturers' Association Inc. 9th Floor Toranomon Building No. 15 Shiba Toranomon Minato-Ku Tokyo Japan; Dear Mr. Ohgiya: This responds to your April 22, 1974, petition to permit the use of th DOT symbol on tires to which no standard applies.; The provisions appearing in the April 3, 1974, *Federal Register* (3 FR 12104) are amendments to the standard, and your submission is in effect a petition for reconsideration of these changes.; Our reasons for prohibiting the use of the DOT symbol on ties to whic no motor vehicle safety standard is applicable are listed in notice 7. We have found the expense of covering the label to be justified, to avoid confusio in the symbols's meaning and the concept of compliance. We have determined that means are available to securely cover the DOT symbol, or in the alternative, to remove it after the molding process.; For these reasons, your petition is denied. Sincerely, James B. Gregory, Administrator |
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.