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: aiam4597OpenThe Honorable Leon E. Panetta House of Representatives Washington, DC 20515; The Honorable Leon E. Panetta House of Representatives Washington DC 20515; "Dear Mr. Panetta: This letter responds to your inquiry on behalf o your constituent, Mr. Botelho. You asked whether Federal regulations require mirrors to be placed on the right side of vehicles and whether such mirrors must be convex in nature. Mr. Botelho expressed his objection to requiring convex mirrors, because he believes convex mirrors distort images and cause objects to appear further away than they actually are. I am pleased to have this opportunity to explain this requirement and its background for you. Standard No. 111, Rearview Mirrors (49 CFR /571.111, copy enclosed)) establishes performance and location requirements for the rearview mirrors installed in new vehicles. Specifically, a passenger car whose inside rearview mirror does not meet the field of view requirements of section S5.1.1 must have an outside mirror on the passenger side of either unit magnification or a convex mirror. In a September 2, 1982 final rule amending Standard No. 111, the National Highway Traffic Safety Administration (NHTSA) explained that convex mirrors offer safety benefits by providing an expanded field of view to the rear, thereby reducing the need for the driver to turn around to view the rear directly. On the other hand, some users of convex mirrors that were used to the images shown by conventional plane mirrors incorrectly perceived that the object shown in the convex mirror was further to the rear than it actually was. Additionally, some users of convex mirrors experienced double vision, eyestrain, and nausea. After considering these potential advantages and disadvantages, NHTSA amended Standard No. 111 so that it does not require any vehicle to be equipped with convex mirrors, but it permits the use of convex mirrors on the passenger side of cars and light trucks, provided that the convex mirror meets certain additional requirements. The additional requirements applicable to convex mirrors on the passenger side of cars and light trucks are: 1. A maximum radius of curvature for the convex mirror. This limits the range of convexities to which drivers will be exposed. It also ensures that the field of view will be noticeably greater than for a plane mirror. 2. A minimum radius of curvature for the convex mirror. This ensures that the image size in the convex mirror will be adequate and distortion will not be excessive. 3. A stringent maximum permissible variation in the radius of curvature over the surface of the convex mirror. This requirement, which is more stringent than the European requirement in this area, also ensures that convex mirrors will have low distortion. 4. A warning etched on the convex mirror that objects shown in the mirror are closer than they appear. This requirement ensures that the driver who may not be familiar with convex mirrors will not be misled by the image size of the convex mirror and the apparent distance to the object. Hence, we agree with Mr. Botelho that the areas he has identified are potential problems unique to convex mirrors. However, our standard includes special requirements for convex mirrors to minimize the potential problems identified by Mr. Botelho and other potential problems that were identified in research studies of convex mirrors. We are not aware of any data showing that convex mirrors that comply with those special requirements present any unacceptable problems for drivers. I hope this information is helpful. If you have any further questions or need any additional information on this subject, please let me know. Sincerely, Erika Z. Jones Chief Counsel Enclosure"; |
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ID: aiam3252OpenMr. Mark Wood, MPI, Inc., P.O. Box EE, Coldwater, MS, 38618; Mr. Mark Wood MPI Inc. P.O. Box EE Coldwater MS 38618; Dear Mr. Wood: This confirms your April 9, 1980, telephone conversation with Roge Tilton of my staff in which you asked whether a styrofoam board that lies beneath a layer of polyurethane foam would be required to comply with the flammability requirements of Standard No. 302, *Flammability of Interior Materials*.; As Mr. Tilton explained to you, the standard applies to seatin components such as yours only to the extent that they fall within 1/2 inch of the occupant compartment air space. This requirement is specified in paragraph S4.2 of the standard. You indicate that your styrofoam board would not fall within 1/2 inch of the compartment because the polyurethane cover will always be thicker than 1/2 inch. Assuming this is true, your styrofoam board would not be required to comply with the standard.; Sincerely, Frank Berndt, Chief Counsel |
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ID: aiam1795OpenMr. William H. Toller, Manager Customer Service, MacDermid Incorporated, 526 Huntingdon Avenue, Waterbury, CT 06720; Mr. William H. Toller Manager Customer Service MacDermid Incorporated 526 Huntingdon Avenue Waterbury CT 06720; Dear Mr. Toller: This is in response to your letter of January 22, 1975, commenting o the recent proposal by the National Highway Traffic Safety Administration (NHTSA) to reduce the performance requirements for motor vehicle bumpers.; Under current Federal requirements, a vehicle bumper must be capable o withstanding 5-mph longitudinal front and rear barrier and pendulum impacts without experiencing certain types of specified damage. A recent NHTSA study, however, indicated that due to inflation, increasing shortages of certain materials, and the weight and cost of current production bumpers, the costs imposed by implementation of the bumper standard may be exceeding the benefits to be derived therefrom.; The proposed reduction in the requirements to 2 1/2 mph front and rea barrier and pendulum impacts was viewed as a means of attaining a favorable cost-benefit ratio by permitting the removal of certain heavy bumper system components. Considerable interest has been manifested in the contents of the proposal. The NHTSA conducted a public hearing on February 18 and 19, 1975, in order to permit the presentation of views from all interested persons regarding the proposed revision of the bumper standard.; The comment period for the notice has been extended until March 3 1975, in order to allow additional time for submission of comments and enable a full review of all evidence presented.; The comments contained in your letter will be placed in the appropriat public docket and will be considered in the formulation of the final rule.; Yours truly, James C. Schultz, Acting Chief Counsel |
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ID: aiam0887OpenMr. Kenneth D. Uding, Sales Promotion, Stimsonite Division, Amerace-Esna Corp., 3445 North Kimball Avenue, Chicago, Illinois 60618; Mr. Kenneth D. Uding Sales Promotion Stimsonite Division Amerace-Esna Corp. 3445 North Kimball Avenue Chicago Illinois 60618; Dear Mr. Uding: This is in response to your request for an interpretation of Standar 125, Warning Devices, with respect to the required marking of the date of manufacture on the device. I apologize for the delay in answering your letter. You inquire whether a circular marking in which the last numeral of the year of manufacture is printed inside an inner circle and the month of manufacture is represented by 'small dots' in an outer circle meets the requirements of S5.1.4.; S5.1.4 requires the device to be 'permanently and legibly marked wit ... month and year of manufacture, which may be expressed numerically, as '6/72' ...' The intent of this provision is not only to 'identify subquality batches' to the manufacturer or enforcement personnel, but also to provide the consumer with a clear indication of the date of manufacture in case of a possible defect or failure to meet safety standards. The method of marking the date of manufacture which you propose would not satisfy the language or intent of the requirement, since its meaning would not be clear to the average consumer.; Sincerely, Richard B. Dyson, Assistant Chief Counsel |
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ID: aiam3602OpenThe Honorable Bob McEwen, House of Representatives, Washington, DC 20515; The Honorable Bob McEwen House of Representatives Washington DC 20515; Dear Mr. McEwen: This responds to your July 8, 1982, letter to Mr. William Dabaghi o the Department enclosing correspondence from your constituent Mr. Donald M. Robinson. Mr. Robinson would like to know whether Federal regulations prohibit him from purchasing a pickup cab and chassis without the body attached. The answer to his question is no.; The National Highway Traffic Safety Administration only requires tha all vehicles be manufactured in compliance with the applicable motor vehicle safety standards. We have no requirement, nor do we know of any other Federal regulation, that would prevent Mr. Robinson from purchasing just the cab and chassis of a vehicle that he desires. When he adds his own utility body to the cab and chassis, he would become the final-stage vehicle manufacturer and would be required to certify that the completed vehicle complies with all applicable Federal safety standards. I am enclosing copies of the regulations pertinent to such an operation.; If I can be of further assistance to you or Mr. Robinson, pleas contact me.; Sincerely, Diane K. Steed, Administrator |
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ID: aiam2910OpenMr. Ralph T. Millet, Director, Governmental Relations, Saab-Scania of America, Inc., Saab Drive, P.O. Box 697, Orange, Connecticut 06477; Mr. Ralph T. Millet Director Governmental Relations Saab-Scania of America Inc. Saab Drive P.O. Box 697 Orange Connecticut 06477; Dear Mr. Millet: This is in response to your letter of 25 October 1978 concerning th requirements of S3.3 of Standard No. 201 as it applies to the instrument panel compartment door in the Saab 900. Your specific concern is the portion of S3.3 that provides, 'Additionally, any interior compartment door located in an instrument panel or seat back shall remain closed when the instrument panel or seat back is tested in accordance with S3.1 and S3.2.'; According to your letter, the hinges on the Saab 900 instrument pane compartment door are designed to deform to keep the compartment door closed if deformation resulting from the head impact requirements of S3.1 is great enough to open the compartment latch.; If the instrument panel compartment door remains closed during the hea impact tests of S3.1, the vehicle complies with that aspect of the requirements of S3.3 of Standard No. 201. The standard does not specify that the latch mechanism remain closed, only that the door 'shall remain closed.'; This interpretation should not be construed as an approval of Saab' instrument panel compartment door hinge system. Federal motor vehicle Safety standards are written primarily in terms of performance requirements which must be met in specified test, and a manufacturer is free to use any design it wishes to meet those performance requirements. Thus, this agency does not grant approval of specific systems or components in the vehicle. The manufacturer must exercise due care to assure that its vehicles comply with all applicable safety standards.; Please let me know if you have any further questions. Sincerely, Joseph J. Levin, Jr., Chief Counsel |
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ID: aiam4128OpenMr. Benjamin R. Jackson, Executive Director, Automobile Importers Compliance Association, 1607 New Hampshire Avenue, N.W., Washington, DC 20009; Mr. Benjamin R. Jackson Executive Director Automobile Importers Compliance Association 1607 New Hampshire Avenue N.W. Washington DC 20009; Dear Mr. Jackson: This responds to your letter following up our correspondence regardin the designation of the target zones under 49 CFR Part 541, *Federal Motor Vehicle Theft Prevention Standard*. In this letter, you quoted the statement in my February 4, 1986, letter to you that NHTSA 'knows of a number of means of inscribing numbers on curved surfaces that would permit direct importers to mark those surfaces within the $15 cost limit.' You asked me to provide information to you on the means of inscription to which I referred, including the name of the process and the address and the telephone number of supplier firms.; The means of inscribing curved surfaces to which I referred in m previous letter to you include technologies such as chemical etching, sandblasting, 'shot-peening', and hard-point vibration. Each of these technologies would enable a person to inscribe markings on curved surfaces, and none requires the purchase of very expensive equipment.; This agency does not provide commercial referrals of supplier firms fo a number of reasons. Section 606(c) of the Motor Vehicle Information and Cost Savings Act (15 U.S.C. 2026(c)) requires each *manufacturer* to certify that its vehicles comply with the theft prevention standard. For this reason, NHTSA does not approve, endorse, or certify that any particular means of marking complies with the theft prevention standard. A listing of supplier firms might be viewed as an approval or endorsement of those firms and their means of marking, and be contrary to the statutory requirement.; Further, as a policy matter, this agency does not provide commercia referrals even absent statutory requirements. By listing a group of supplier firms, the agency would give those firms an unintended 'government sanction' for their products. Conversely, any such listing would unintentionally denigrate all firms not included in the listing. Any commercial referrals by this agency would give rise to these potential problems no matter what disclaimers NHTSA attached to the referral.; The theft prevention standard is a performance standard that specifie criteria with which the markings used by your group must comply. You are free to choose the means of compliance. In making that choice, you will have to use your business judgment to decide whether you should inscribe the markings yourself or pay someone else to inscribe the markings. If you choose to pay someone else to inscribe the markings, the choice of whom you should select would again be your decision.; Sincerely, Erika Z. Jones, Chief Counsel |
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ID: aiam3317OpenMr. Rick P. Golde, Project Engineer, Vetter Corporation, 1150 Laurel Lane, San Luis Obispo, CA 93401; Mr. Rick P. Golde Project Engineer Vetter Corporation 1150 Laurel Lane San Luis Obispo CA 93401; Dear Mr. Golde: This is in reply to your letter of May 28, 1980, with respect to you proposals for lighting requirements for a motorcycle sidecar currently under development. Your letter does not state so, but you indicated in your telephone conversation with Mr. Vinson of this office that the sidecar is detachable.; It has been the position of this agency that a detachable sidecar is a item of motor vehicle equipment to which no Federal motor vehicle safety standards apply. Conformance of the motorcycle therefore is judged without the sidecar attached. Therefore, the front turn signal configuration in Figure F2 would appear to meet Standard No. 108 but the asymmetrical one in Figures F1 and F3 would not. Similarly, the rear turn signal and stop lamp configurations in Figure R2 appear to comply, but those of Figures R1 and R3 do not. The configuration of Figure R4 is not prohibited by S4.1.2 since it does not appear to impair the effectiveness of the required lighting equipment. As for Figure R5, the reflective itself and its appearance solely on the sidecar, as indicated on your drawing, is improper. Finally, your Figure S1 depicts front and rear reflex reflectors mounted on the right side of the sidecar. This is not acceptable as a substitute for the required front and rear reflectors on the right side of the motor as you indicate but we believe it would enhance safety if you incorporated this idea into production.; If you have any further questions, please let us know. Sincerely, Frank Berndt, Chief Counsel |
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ID: aiam4578OpenPeter J. Yanowitch, Esq. Messrs. Davis, Markel, & Edwards 66 West Flagler Street, SUite 608 Miami, FL 33130 Re: Importation of Porsche 959; Peter J. Yanowitch Esq. Messrs. Davis Markel & Edwards 66 West Flagler Street SUite 608 Miami FL 33130 Re: Importation of Porsche 959; "Dear Mr. Yanowitch: This is in reply to your letter of February 27 l989, requesting a response by March l0 as to whether the Department would permit the importation of a Porsche 959 pursuant to l9 CFR 12.80(b)(1)(v). Specifically, you represent a non-resident of the United States who wishes to import such a vehicle, and operate it on the public roads of this country during the l-year period. You have asked for confirmation in writing that if the vehicle is imported on this basis that 'the Department of Transportation would not have jurisdiction to impound, confiscate, destroy, require a bond, or otherwise take any action with respect to the vehicle, so long as the non-resident fully complies with the provisions' of 12.80(b)(l)(v), and, further, that the Department 'would not object to the non-resident driving this vehicle on the road' while it is in the United States. You also state that your client is prepared to submit 'sworn testimony that he will comply with the requirements of the United States Customs Regulations.' Under l9 CFR 12.80(b)(l), each vehicle offered for introduction into the Customs territory of the United States shall be denied entry unless the importer files a declaration which declares that '(v) The importer...is a non-resident of the United States, is importing the vehicle...primarily for personal use for a period not exceeding l year from the date of entry, will not sell it in the United States during that period, and has stated his passport number and country of issue...in the declaration.' This provision was adopted in recognition of international treaties to which the United States is a party, which are intended to assure the free flow of international road traffic. However, this agency does not construe either the regulation or the treaties as conferring an absolute right upon any non-resident to import a non-conforming vehicle if considerations of policy dictate a determination that such entry would not be in the interests of the United States. Chief among these considerations is whether the importer has previously imported a motor vehicle in violation of the importation regulations. Accordingly, we wish to review your client's declaration before the time the vehicle arrives at the port of entry. I enclose a copy of our Form HS-7 for its completion and return to us. We request that a photocopy of the title or other certificate of ownership be enclosed as well. We also ask that a statement be attached to the declaration, so that it becomes a part of it and subject to penalties in the event that it is false or misleading, in which your client discloses whether he has ever imported into the United States any motor vehicle manufactured on or after January l, l968, and, if the answer is affirmative, to provide the make, model, and port and approximate date of entry, and the name of the importer or consignee as it appeared on the declaration. Finally, we also request an affirmation from your client that he will not sell the vehicle, or offer it for sale, either before or during its stay in the United States, and that he will export it at the end of the l-year period. When we have received and reviewed the declaration and statement we shall be pleased to consider this matter further, and we shall answer your questions at that time. Sincerely, Erika Z. Jones Chief Counsel Enclosure"; |
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ID: aiam1280OpenMr. Roy Case, Twin Coach Highway Products Incorporated, Kent, OH 44240; Mr. Roy Case Twin Coach Highway Products Incorporated Kent OH 44240; Dear Mr. Case: Thank you for your letter of August 22, 1973, concerning th requirements of Federal Motor Vehicle Safety Standard No. 217, Bus Window Retention and Release.; Following are answers to your four questions: >>>1. In a phone conversation with Richard Dyson on September 26 yo explained that the window mechanism in question (which you mentioned you are no longer using) requires the release of both mechanisms before the window releases -- that is, before the window will no longer conform to the retention requirements in paragraph S5.1, S5.1.1, and S5.1.2 of the standard. In this case, only one of the force applications necessary to operate both mechanisms need differ by 90 degrees to 180 degrees from the direction of the original push-out motion of the emergency exit.; 2. You are correct that the post in front of the window is not a obstruction so long as it permits passage of the ellipsoid. However, when a post cuts a window opening into two segments as shown in your enclosed sketch, only the segment that passes the ellipsoid, not the entire window opening, may count toward the measurement of total area specified in paragraph S5.2.; 3. Although Figure 3C shows only the boundaries for high and low forc access regions when the bus is upright (and when an obstacle is between the occupant and the unit), these same dimensions are these that are to be applied when the bus is overturned on either side, with the side on which the bus is resting being considered as the floor. The transposition of these dimensions is illustrated to some extent in Figure 3D.; Whether or not both rear windows must be made into emergency exit rests solely on whether both windows are necessary for the bus to meet the unobstructed opening requirements, and the emergency exit release requirements of S5.3 and S5.5 when the bus is upright and overturned on either side.; 4. The cut-off date for windows which do not comply with the standar is that of the date of manufacture of the bus in which the window is installed. All buses manufactured on or after September 1, 1973, must comply with the requirements of Standard No. 217.<<<; If I can be of further assistance, please do not hesitate to ask. Sincerely, Robert L. Carter, Associate Administrator, Motor Vehicle Programs |
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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.