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: nht76-2.13OpenDATE: 04/30/76 FROM: AUTHOR UNAVAILABLE; S. P. Wood; NHTSA TO: Transportation Design & Technology, Inc. TITLE: FMVSS INTERPRETATION TEXT: This responds to your November 14, 1975, request to know how the tensile strength at a joint is determined under S6.2 of Standard No. 221, School Bus Body Joint Strength, in the case of more than two body components joined by the same fastener. An extensive discussion of joint strength requirements and test procedures was recently sent to Blue Bird Body Company. Your question is addressed in that discussion and a copy is enclosed for your information. YOURS TRULY, Transportation Design & Technology, Inc. 14 November 1975 Mr. Frank A Berndt Acting Chief Counsel U.S. Department of Transportation National Highway Traffic Safety Administration I have been asked to contact your office for a clarification of the joint integrity ruling. Where two pieces of sheet metal overlap to form a joint and are also attached to a body post of a much higher yield material, does the joint calculations apply to the surface metals only or should the higher yield material of the inner post be taken into account? There appears to be some doubt in the minds of several people I have spoken with and therefore, I would appreciate your comments at your earliest convenience. L. W. Smith President |
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ID: nht90-3.18OpenTYPE: Interpretation-NHTSA DATE: July 13, 1990 FROM: S. Watanabe -- General Manager, Automotive Equipment Technical Coordination Dept., Stanley Electric Co., Ltd. TO: Stephen P. Wood -- Acting Chief Counsel, NHTSA TITLE: None ATTACHMT: Attached to letter dated 8-30-90 from P.J. Rice to S. Watanabe (A36; Std. 108) TEXT: We would like to ask you a question about a configuration of combination rear lamp which fulfils both tail and rear side marker functions as sketched below. (Graphics omitted) In accordance with the requirement of S.5.5.7 of FMVSS No. 108, the two functions (ie. Tail & Side marker) are presented at the same time. Thus the light output of side marker lamp is also emanated toward the rear of the vehicle mixed with tail lamp ligh t, and similarly, the light output of tail lamp is also emanated toward the side mixed with side marker lamp light. Please let us have your answers to the following questions. 1) Should the Tail lamp function of this lamp meet the photometric requirements for 2 lighted sections, or 3 lighted sections? 2) Should the Side marker function of this lamp meet the photometric requirement of SAE J592e by 3 lighted sections or 1 lighted section? I greatly appreciate receiving your reply to the above as soon as possible. |
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ID: nht90-3.53OpenTYPE: Interpretation-NHTSA DATE: August 8, 1990 FROM: Hiroshi Ozeki -- Executive Vice President, Mazda Research & Development of North America, Inc. TO: Paul Jackson Rice -- Chief Counsel, NHTSA TITLE: Re Request for interpretation of FMVSS No. 214, "Side Door Strength" ATTACHMT: Attached to letter dated 3-12-91 from Paul Jackson Rice to Hiroshi Ozeki (A37; Std. 214) TEXT: The purpose of this letter is to request an interpretation of Federal Motor Vehicle Safety Standard No. 214, "Side Door Strength". Specifically, Mazda would like NHTSA's interpretation of the definition of the phrase, "...(t)he lowest point of the door;" . This phrase is found at S4(c)(2) under test procedures. One of Mazda's future models has a door design in which the door moulding extends below the door itself by approximately 15 mm (please see attached figure). Thus, in order that the loading device used for compliance testing is positioned properly, Mazda needs to know what position, A or B, is the "lowest point of the door". Should you have any questions regarding this request, please do not hesitate to contact either Mr. Rob Strassburger (313-930-2513) of my staff or Mr. Ted Kadoya (626-3263) at our Washington D.C. office. Attachment Drawing of side doors and moulding (Graphics omitted) |
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ID: nht89-1.72OpenTYPE: INTERPRETATION-NHTSA DATE: 04/14/89 FROM: VIRVE AIROLA -- OY TOPPI AB FINLAND TO: NHTSA TITLE: NONE ATTACHMT: ATTACHED TO LETTER DATED 05/31/90 FROM STEPHEN P. WOOD -- NHTSA ACTING CHIEF COUNSEL TO VIRVE AIROLA; LETTER DATED 01/26/72 FROM RICHARD B. DYSON -- ASSISTANT CHIEF COUNSEL NHTSA TO K. NAKAJIMA -- TOYOTA TEXT: Gentlemen; Our company, Oy Toppi Ab, is a Finnish producer of plastic tubes and hoses. One of our most important products is Air Brake Tubing made of Polyamide PA 11. We produce this tubing both conforming to SAE J 844 and to the German standard DIN 74324. For some time ago we quoted our tubes to the Swedish truck and bus producer Saab-Scania AB and received their product standard. Among other things this standard states following: Quote: the manufacturer shall be registered at NHTSA in USA and the symbol DOT constituting certification by the manufacturer that the hose conforms to all applicable FMVSS standards. quote We have no doubt that we will fullfill the requirements for the register and would appreciate it if you could send us the application formula as soon as possible. In case any information or details are needed, please let us know and we will send them for you immediately. Brochures [OMITTED] |
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ID: 1985-04.33OpenTYPE: INTERPRETATION-NHTSA DATE: 11/19/85 FROM: AUTHOR UNAVAILABLE; Erika Z. Jones; NHTSA TO: Mr. Karl-Heinz Faber -- Vice President, Mercedes-Benz of North America, Inc. TITLE: FMVSS INTERPRETATION TEXT: Mr. Karl-Heinz Faber Vice President Mercedes-Benz of North America, Inc. One Mercedes Drive P.O. Box 350 Montvale, New Jersey 07645 Thank you for you letter of August 12, 1985, to Administrator Steed, telling us of your plans to identify Mercedes-Benz vehicles which are equipped with your Supplemental Restraint System. You stated that, beginning with model year 1986, you plan to use the vehicle identification number (VIN) plate location for this purpose. The attachments to your letter depict a VIN plate which indicates whether the vehicle is equipped with an air bag for the driver or for both front seating positions. As long as the requirements of Standard No. 115, Vehicle Identification Number--Basic Requirements, and Part 565, Vehicle Identification Number--Content Requirements, are met, we believe your plan to use the VIN plate location to identify an air-bag equipped car in this manner should be useful. We agree that it should enable service departments, dismantlers, or recyclers to quickly and easily note that a vehicle is equipped with an air bag. Sincerely, Original Signed By Erika Z. Jones Acting Chief Council |
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ID: 86-5.20OpenTYPE: INTERPRETATION-NHTSA DATE: 09/16/86 FROM: AUTHOR UNAVAILABLE; Erika Z. Jones; NHTSA TO: Mr. Skip Maraney TITLE: FMVSS INTERPRETATION TEXT:
Mr. Skip Maraney National Star Route Mail Contractor Association 324 East Capitol Street Washington, DC 20003
Dear Mr. Maraney:
This responds to your telephone inquiry about whether our regulations would prohibit the installation of a right hand drive steering system in a motor vehicle. We do not have any standards that prohibit the use of a right hand drive steering system. We have, however, issued two safety standards (Standard Nos. 203 and 204) that set performance requirements which apply to any steering system, whether left or right hand drive, installed in new passenger cars and light trucks, buses, and multipurpose passenger vehicles. A copy of each of these standards is enclosed.
You also asked about the agency's regulations on the importation of motor vehicles. I have enclosed a copy of a publication, "Instructions Handbook for Complying with Regulations on Imported Vehicles," which will provide you with information about our importation regulations.
If you have any further questions, please let me know. Sincerely,
Erika Z. Jones Chief Counsel
Enclosures |
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ID: 1984-1.39OpenTYPE: INTERPRETATION-NHTSA DATE: 04/11/84 FROM: AUTHOR UNAVAILABLE; Frank Berndt; NHTSA TO: Mazda (North America) Inc. TITLE: FMVSS INTERPRETATION TEXT:
Mr. Stephen Underwood Mazda (North America), Inc. 23777 Greenfield Road Suite 462 Southfield, Michigan 48075
Dear Mr. Underwood:
This is to follow up on your phone conversation with Stephen Oesch of my staff on Standard No. 203, Impact Protection for the Driver From the Steering Control System. You asked how the steering wheel should be positioned when it is tested in accordance with the standard. As explained below, the steering wheel should be positioned at its design angle, as specified by the manufacturer. Standard No. 203 incorporates by reference Society of Automotive Engineers Recommended Practice J944, Steering Wheel Assembly Laboratory Test Procedure, December 1965. Section 6.2 of SAE J944 provides that the steering wheel is to be mounted "at the proper angle as determined by the package drawing." Therefore, the agency would mount the column at the design angle specified by the manufacturer.
If you have any further questions, please let me know. Sincerely,
Frank Berndt Chief Counsel |
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ID: nht81-3.42OpenDATE: 11/20/81 FROM: AUTHOR UNAVAILABLE; F. Berndt; NHTSA TO: Fruehauf Corporation TITLE: FMVSS INTERPRETATION TEXT: This responds to your recent letter to Mr. Kratzke of my staff concerning the requirements of Federal Motor Vehicle Safety Standard No. 120 (49 CFR @ 571.120). Specifically, you asked if retreaded tires could be mounted on new trucks and trailers, and what requirements those tires would have to meet. Retreaded tires can be mounted on new trucks and trailers without violating Standard 120. For your information, I have enclosed a copy of a 1978 interpretation concerning Standard 120 which explains that retreaded tires can be mounted on new trucks and trailers in compliance with the standard. The only requirements those tires would have to meet is that the sum of the maximum load ratings for the tires would have to be at least equal to the gross axle weight rating of the axle to which they were fitted, as specified in section @ 5.1.2 of the Standard 120. As explained in the attached letter, there is no requirement that the retread meet the requirements of Standard 119 because those requirements are inapplicable to retreads. Further, there is no requirement that the retreads have the DOT symbol. If you have any further questions, please contact Mr. Kratzke at (202) 426-2992. |
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ID: nht73-6.4OpenDATE: 11/12/73 FROM: AUTHOR UNAVAILABLE; Robert L. Carter; NHTSA TO: Honorable John B. Conlan, U.S. House of Representatives COPYEE: SEC. REP. DUNN; DR. KAYE; J. L. LEYSATH; MR. VINSON TITLE: FMVSS INTERPRETATION TEXT: This will supplement the Bureau of Motor Carrier Safety's reply of October 30, 1973, to your letter of September 21, 1973, to the Interstate Commerce Commission, concerning Mr. William H. Arendell's automatic light-blinking device for truck signaling. The Bureau has referred your letter to us for further reply. Enclosed for your constituent's information is a copy of Federal Motor Vehicle Safety Standard No. 108, entitled, "Lamps, Reflective Devices and Associated Equipment." The effect of paragraph S4.6 of the standard is to prohibit the use of automatic flashing clearance lamps for signaling purposes on vehicles manufactured on or after January 1, 1972. The term "flash" is defined (paragraph S3) as "a cycle of activation and deactivation of a lamp by automatic means continuing until stopped either automatically or manually." It appears that the device described in your constituent's letter falls within the prohibition of Standard No. 108, and could not be used as original equipment on vehicles. Its use as an aftermarket device would be subject to regulation by the individual States. I trust the above information will be of interest to Mr. Arendell. 2 ENCLS. CONSTITUENT'S LETTER STD. NO. 108 |
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ID: nht78-3.25OpenDATE: 10/02/78 FROM: AUTHOR UNAVAILABLE; J. J. Levin, Jr.; NHTSA TO: Thomas Built Buses, Inc. TITLE: FMVSS INTERPRETATION TEXT: This responds to your August 25, 1978, letter asking what the term "normal nighttime illumination" mean in Standard No. 217, Bus Window Retention and Release. The term "normal nighttime illumination" is found in paragraph S5.5.2 of the standard. This section requires that all interior exit instructions be legible when the only source of light is the normal nighttime illumination of the vehicle. The term, as used in this paragraph, means that exist instructions must be visible with the normal interior vehicle lighting that is in use when the bus is moving. Interior vehicle lighting may include, for example, reading lamps and overhead lights. SINCERELY, Thomas BUILT BUSES, INC. August 25, 1978 Office of the Chief Counsel U.S. Department of Transportation Attn: Roger Tilton Subject: MVSS 217, Section S5.5.2 - School Bus Dear Mr. Tilton: We are inquiring if a definition has been given to the phrase "Normal Nighttime Illumination". Our interpretation is that the interior lights in the vehicle constitude "Normal Nighttime Illumination". We are most interested in hearing from you in this matter. James Tydings, Specifications Engineer |
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.