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: aiam3237OpenMr. Francois Louis, Governmental Affairs, Renault USA, 14250 Plymouth Road, Detroit, MI 48232; Mr. Francois Louis Governmental Affairs Renault USA 14250 Plymouth Road Detroit MI 48232; Dear Mr. Louis: This responds to your letter of March 3, 1980, requesting a interpretation concerning the proper designated seating capacity for the rear seat in the Renault Le Car vehicle. You state that the rear seat of the Le Car has 48.2 inches of hip room, and ask whether the vehicle would qualify as having only two designated seating positions.; I am enclosing a copy of a letter of interpretation the agency recentl issued to Toyota Motor Company regarding the designated seating capacity of the rear seats in several of its models. The rear-seat designs of these Toyota models are very similar to the Le Car, in that the presence of wheel wells results in hip room measurements below 50 inches under the strict measurement technique specified in the definition of 'designated seating position' (SAE J1100a). As was pointed out in that letter, however, if occupants move their hips slightly forward of the wheel wells, which extend only a few inches out into the seat, there is over 50 inches of usable hip room in these vehicles.; Your letter states that the close proximity of the two inboard portion of the rear seat belt assemblies in the Le Car indicates that only two positions are intended by the manufacturer. The agency would give more credence to this factor if the inboard portions of the belt assemblies were on stiff, immovable cables (or similar design). With the current design, a person wishing to sit in the center position can easily move the belts out of the way, so the belts are not real impediments to use of the center position.; In answer to your ultimate question, the agency must conclude that th rear seat in the Le Car vehicle could qualify as having only two designated seating positions since the hip room is below 50 inches according to the technical measurement procedure specified in the standard. However, we think this is an extremely close case since there is over 48 inches of hip room even between the wheel wells and greater than 50 inches of hip room if the measurement is made mid-way the seat cushion. Therefore, we strongly urge Renault to modify its seat design or to add a third set of belts in this vehicle model. As noted in the letter to Toyota, if manufacturers do not voluntarily comply with the clear intent of the definition of 'designated seating position', the agency may find it necessary to modify the measurement technique that is currently specified.; Sincerely, Frank Berndt, Chief Counsel |
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ID: aiam4458OpenMrs. Charlotte E. O'Neil l46 Transit Street Waterbury, CT 06704; Mrs. Charlotte E. O'Neil l46 Transit Street Waterbury CT 06704; "Dear Mrs. O'Neil: This responds to your letter concerning the locatio of the clutch, brake and accelerator controls in a school bus that you drive. We apologize for the delay in our response. You stated that the seat of the school bus is about four inches too far to the right, and that these controls are therefore not in the usual location relative to the seat. You stated: 'In order to reach the brake pedal I have to cross my right foot over my left,' and expressed concern that a driver might accidentally hit the accelerator instead of the brake. You asked whether Federal Motor Vehicle Safety Standard No. l0l, Controls and Displays, prohibits placing controls in such difficult to reach locations and, if not, whether there is any way to get the law changed. The National Highway Traffic Safety Administration (NHTSA) issues safety standards covering new motor vehicles and/or new motor vehicle equipment. Since these standards do not apply to used vehicles, the issue of whether the bus you drive was required to meet Standard No. l0l depends on its date of manufacture. As you noted in your letter, Section S5.l of Standard No. l0l requires that certain controls, including the service brake, accelerator, and clutch, be 'operable by the driver' when the driver is restrained by the crash protection equipment required by Standard No. 208. You asked whether, with this wording, any control that can be reached at all, even with difficulty, must be considered 'operable.' One of the stated purposes of Standard No. l0l is 'to ensure the accessibility . . . of motor vehicle controls . . . in order to reduce the safety hazards caused by the diversion of the driver's attention from the driving task, and by mistakes in selecting controls.' Thus, it is the intent of section S5.l to ensure that drivers are able to operate specified controls as part of the normal driving task. We note, however, that neither Standard No. l0l nor any other standard specifies the precise location of the service brake, accelerator and clutch controls, either relative to each other or to the seat. In answer to your question concerning how you may be able to get requirements changed 'to forbid putting controls in difficult to reach locations,' interested persons may petition the agency to commence rulemaking to issue or amend safety standards. I am enclosing a copy of the agency's regulation which sets forth procedures for submitting petitions for rulemaking. I am forwarding your letter to NHTSA's Office of Enforcement, which investigates consumer complaints about safety. A copy of this correspondence is being placed in the public docket. Sincerely, Erika Z. Jones Chief Counsel Enclosure"; |
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ID: aiam3667OpenMr. Houtan Mostaghim, Vice President, Pan United Inc., 154 Hillwood Avenue, Falls Church, VA 22046; Mr. Houtan Mostaghim Vice President Pan United Inc. 154 Hillwood Avenue Falls Church VA 22046; Dear Mr. Mostaghim: This responds to your letter of March 4, 1983, asking whether there ar any Federal regulations applicable to an accessory component used to secure pets to vehicle seat belts. The component latches into the seat belt buckle and is then attached to the pet's collar or leash. Your company intends to import these accessories.; There are no Federal motor vehicle safety standards or regulation applicable to the product you describe. Therefore, as far as this agency is concerned, there are no responsibilities you must meet prior to importing this item (i.e., there are no testing or licensing requirements). You should, however, contact State authorities to determine if they have any licensing requirements or regulations that would be applicable to the sale of such a device.; You will have to contact private counsel to determine the produc liability implications and insurance needs of your enterprise.; Thank you for your inquiry. Sincerely, Frank Berndt, Chief Counsel |
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ID: aiam0948OpenMr. Edward L. Hawes, President, Hawes Industries, Inc., 1651 E. 9 Mile Road, Hazel Park, Michigan 48030; Mr. Edward L. Hawes President Hawes Industries Inc. 1651 E. 9 Mile Road Hazel Park Michigan 48030; Dear Mr. Hawes: This is in response to your letter of December 7, 1972, regardin Standard 125, Warning Devices. I am sorry that you misunderstood our previous letter of November 27, 1972. We believe that the standard clearly permits the manufacture and sale of your device, for the reasons already discussed, and therefore an amendment is unnecessary. If you still have questions on this matter, do not hesitate to call me.; Yours truly, Richard B. Dyson, Assistant Chief Counsel |
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ID: aiam2975OpenMr. J. B. H. Knight, Chief Car Safety Engineer, Rolls-Royce Motors, Crewe Cheshire, CW1 3PL, England; Mr. J. B. H. Knight Chief Car Safety Engineer Rolls-Royce Motors Crewe Cheshire CW1 3PL England; Dear Mr. Knight:#This responds to your letters of July 11, 1978, an January 18, 1979, concerning Federal Motor Vehicle Safety Standard (FMVSS) 101-80, *Controls and Displays*. I regret the delay in responding to your inquiry. The answers to your questions are as follows:#1. The turn signal control lever used by Rolls-Royce is mounted on the steering column and is positioned horizontally. To operate the turn signals, the lever must rotated either clock-wise or anti-clock-wise. To label the control lever and to indicate the manner of operation, Rolls-Royce is considering placing the arrows of the turn signal symbol so that they point up and down. You ask whether the standard permits that orientation of the arrows.#The answer is no. Section 5.2.1 requires that the turn signal symbol appear perceptually upright to the driver. The upright position of a symbol is determined by referring to column 3 of Table 1 of the standard. That table shows that the upright position for the turn signal symbol is with the arrows pointing horizontally. Thus, the arrows must point essentially horizontally in the motor vehicle. Complying with the perceptually upright requirement instead of reorienting the symbol to serve other purposes will aid in ensuring quick and accurate identification of the turn signal control. We wish to observe that essentially the same result as that sought by RollsRoyce (sic) in reorienting the turn signal symbol could be achieved by placing curved, thinner arrows next to the symbol to indicate mode of operation.#2. (i) You noted that differing display identification requirements for safety belts appear in FMVSS 101-80 and FMVSS 208. FMVSS 101-80 does not supersede or preempt FMVSS 208 in this area. However, the agency will soon issue a notice that will provide for use of the safety belt symbol in Table 2 of FMVSS 101-80 for the purposes of both standards.#(ii) You are correct in assuming that column 3 of Table 2 should include a reference to FMVSS 105-75 for brake system malfunction displays and a reference to FMVSS 121 for brake air pressure displays. These inadvertent omissions will be corrected in the notice mentioned above. You are also correct in assuming that the options in section 5.3.5 of FMVSS 105-75 are still available.#3. You referred to the statement in the final rule preamble that the visibility requirements of 101-80 would be deemed satisfied even if minimal movements by the driver were necessary and suggested that this interpretation be incorporated in section 6, conditions, and amplified. The agency does not believe that this step is necessary. The agency does, however, believe it appropriate to amplify its earlier interpretation. By minimal movement, the agency meant head movement of not more than a few inches. By a 'few' inches, we mean up to approximately three inches. As to your suggestion for specifying the size of the driver to be used in determining compliance with the visibility requirements, the agency will consider this suggestion and address it at a future date.#4. You should comply with the speedometer scale requirements in FMVSS 101-80 since the labelling requirements in FMVSS 127 were deleted in the response to reconsideration petitions that was published July 27, 1978 (43 FR 32421).#Sincerely, Frank Berndt, Acting Chief Counsel; |
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ID: aiam3372OpenMr. Stephen E. Mulligan, International Harvester, 401 North Michigan Avenue, Chicago, IL 60611; Mr. Stephen E. Mulligan International Harvester 401 North Michigan Avenue Chicago IL 60611; Dear Mr. Mulligan: This is in response to your letter of October 1, 1980, in which you as whether compliance with 49 CFR 567, Certification, will satisfy the requirements of S4.3 of Federal Motor Vehicle Safety Standard No. 115, 49 CFR 571.115.; Section 4.3 of Federal Motor Vehicle Safety Standard No. 115 require that the vehicle identification number (VIN) 'appear clearly and indelibly upon either a part of the vehicle other than the glazing that is not designed to be removed except for repair or upon a separate plate or label which is permanently affixed to such a part.' S4.3.1 requires each character to appear in a capital, sans serif typeface. In the case of passenger cars and trucks of 10,000 pounds or less GVWR, each character must have a minimum height of 4 mm. S4.4 specifies that the VIN for passenger cars and trucks of 10,000 pounds or less GVWR shall be located within the passenger compartment.; Section 567.4 of Part 567, Certification (49 CFR 567), requires tha the certification label be permanently affixed to the vehicle, and display the vehicle identification number. Consequently, for all vehicles except passenger cars and trucks of 10,000 pounds or less GVWR, compliance with S 567.4 of Part 567 would also effect compliance with S4.3 of Standard No. 115 so long as capital, sans serif typeface was used.; Sincerely, Frank Berndt, Chief Counsel |
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ID: aiam3688OpenMr. James E. Forrester, Manager of Engineering Services, Truck Body & Equipment Association, P.O. Box 70409, Washington, D.C. 20088-0409; Mr. James E. Forrester Manager of Engineering Services Truck Body & Equipment Association P.O. Box 70409 Washington D.C. 20088-0409; Dear Mr. Forrester: This responds to your March 15, 1983, letter asking whether emergenc doors in school buses may be marked as 'emergency exits' and still comply with Standard No. 217, *Bus Window Retention and Release*.; Paragraph S5.5.3 states that each school bus exit shall have th designation 'Emergency door' or 'Emergency exit' as appropriate. The agency has previously determined that emergency doors are considered to be emergency exits and thus can be marked as either doors or exits. Emergency windows must be marked only as emergency exits.; Sincerely, Frank Berndt, Chief Counsel |
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ID: aiam3722OpenMs. Mary Ruth Harsha, Office of General Counsel, 3M Center, P.O. Box 33428, St. Paul, MN 55133; Ms. Mary Ruth Harsha Office of General Counsel 3M Center P.O. Box 33428 St. Paul MN 55133; Dear Ms. Harsha: This responds to your company's recent letter regarding th applicability of Federal motor vehicle safety regulations to the sale and application of sun control films on motor vehicles. You ask whether our November 10, 1976, letter to your company on this same subject is still applicable, as well as several other questions.; Our November 1976 letter is still current. Solar films themselves ar not considered glazing materials under Safety Standard No. 205. As stated in that letter, however, the application of such films to motor vehicles by certain persons does give rise to responsibilities under Federal law. I am enclosing a copy of a recent letter of interpretation which discusses the pertinent Federal law on this subject.; I am also enclosing a copy of a telegram that we recently sent to th Hawaii Department of Transportation which discusses the preemptive effect of Safety Standard No. 205 over State laws governing the same aspect of motor vehicle performance, under the National Traffic and Motor Vehicle Safety Act, as amended (15 U.S.C. 1381, et *seq*. (sic)). The Hawaii legislature has passed a law which attempts to allow dealers and businesses in that State to apply solar films on motor vehicles. Those films are allowed to reduce transmittance down to 35 percent. As pointed out in the enclosed telegram, Safety Standard No. 205 preempts that State statute in certain respects. The letter of interpretation and the telegram should answer all of your questions.; Please note that under Safety Standard No. 205 all windows in passenger car are considered requisite for driving visibility. Thus, all windows in a passenger car must have a light transmittance of at least 70 percent. In vehicles other than passenger cars, typically, only the windshield and front side windows are considered requisite for driving visibility. This means, for example, that a van could have solar films installed on windows behind the driver, since no transmittance requirements are specified for those windows.; I hope this has answered all your questions. Sincerely, Frank Berndt, Chief Counsel |
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ID: aiam2830OpenMr. Frank B. Caristia, President, Christy Electronics, Inc., 51 East 42nd Street, New York, NY 10017; Mr. Frank B. Caristia President Christy Electronics Inc. 51 East 42nd Street New York NY 10017; Dear Mr. Caristia: Our regional office in White Plains has forwarded your letter of Ma 29, 1978, for reply.; You have requested 'approval' of your vehicle lighting system whic flashes the stop lamps at a rate three times per second when the brake pedal is depressed.; We do not 'approve' lighting devices but we do provide interpretation whether such devices are permissible under Federal lighting requirements. As an item of original vehicle equipment your device would appear to be prohibited by paragraph S4.6 of Federal Motor Vehicle Safety Standard No. 108. This paragraph requires that all lamps be steady - burning in operation except for turn signal lamps, hazard warning, signal lamps, and school bus warning lamps, and it also allows headlamps and side marker lamps to be flashed for signalling purposes.; As an aftermarket device, however, it would be subject to regulation b the individual States. We are forwarding a copy of your letter to the American Association of Motor Vehicle Administrators for an opinion on this point.; We appreciate your interest in safety. Sincerely, Joseph J. Levin, Jr., Chief Counsel |
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ID: aiam2563OpenMr. L. Wenderoth, Bandag of Nassau, Inc., 40 Brook Avenue, Deer Park, NY 11729; Mr. L. Wenderoth Bandag of Nassau Inc. 40 Brook Avenue Deer Park NY 11729; Dear Mr. Wenderoth: This responds to your March 10, 1977, letter asking whether it i permissible for you to use a DOT number assigned to another tire retreader when you perform special retread work in your plant for the other retreader who lacks facilities to do the work himself.; Standard No. 117, *Retreaded Pneumatic Tires*, requires that th retreader apply a DOT symbol and identification number to the tire. The DOT symbol indicates conformance with Federal regulations. The number enables the National Highway Traffic Safety Administration (NHTSA) to identify the retreader that manufactures the tire. To permit one manufacturer to use the identification number of another would impair the NHTSA enforcement actions. Accordingly, you would not be permitted to use any DOT number other than your own on tires you retread.; Sincerely, Frank A. Berndt, Acting 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.