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: aiam4409OpenKarl F. Milde, Jr., P.C., Law Offices, RFD #8, Box 369, Union Valley Road, Mahopac, NY 10541; Karl F. Milde Jr. P.C. Law Offices RFD #8 Box 369 Union Valley Road Mahopac NY 10541; Dear Mr. Milde: This is in reply to your letter of October 2, 1987, with reference t an electronic circuit that would automatically activate a vehicle's hazard warning system when the vehicle is proceeding slowly, or has stopped in the roadway. You have asked whether such a system has been proposed before, or field tested, and whether Federal Motor Vehicle Safety Standard No. 108 would permit its installation on motor vehicles.; The traffic hazard that concerns you, especially that presented by vehicle that has stopped in the roadway without activation of either brakes or hazard warning system, is one that is familiar to many motorists. However, it appears that in actuality most motorists confronted with this hazard are able to react in time to avoid a rear end collision. Accident data available to the agency indicate that crashes of this nature are relatively rare. As you know, many States require activation of the hazard warning system at speeds less than 40 mph on the Interstate system. NHTSA has not proposed a system of this nature, nor has it field tested one. The agency has participated in research with deceleration warning systems, a similar though not identical concept, and concluded that safety benefits were insufficient to propose their adoption.; We see no Federal prohibition against installation of a circuit tha would activate the hazard warning system at a predetermined low rate of speed. Equipment that is not prescribed by the lighting standard is permissible as original equipment as long as it does not impair the effectiveness of equipment that Standard No. 108 does require. And modifications of vehicles in use by persons other than the vehicle owner are permissible as long as they do not render inoperative, in whole or in part, vehicle equipment necessary for compliance with a Federal motor vehicle safety standard. Nor are we aware of any State restrictions on the use of such a system, though you should consult the American Association of Motor Vehicle Administrators for a definitive answer. Its address is 1201 Connecticut Avenue, NW, Washington, DC 20036.; Sincerely, Erika Z. Jones, Chief Counsel |
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ID: aiam3636OpenMr. Patrick J. Tyler, Englander, 3429 West 47th Street, Chicago, IL 60632; Mr. Patrick J. Tyler Englander 3429 West 47th Street Chicago IL 60632; Dear Mr. Tyler: This responds to your September 8, 1982, letter asking whether mattress that you manufacture for use in a truck cab would be required to comply with Standard No. 302, *Flammability of Interior Materials*.; Standard No. 302 lists the components that are covered by the standard That list states that mattress covers must comply with the standard's requirements. The agency has interpreted the mattress cover language to mean both mattress covers and the permanent mattress ticking. Accordingly, your mattress to the extent that it is designed for use in new vehicles must comply with the requirements.; You should be aware that nothing prohibits a vehicle owner fro purchasing noncomplying equipment as replacement equipment if he so chooses. You did not indicate whether your operation is for new vehicles or replacement equipment. In the instance of noncomplying replacement equipment, no manufacturer, repair business, or distributor could install such noncomplying equipment. The installation would have to be made by the vehicle owner himself.; Sincerely, Frank Berndt, Chief Counsel |
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ID: aiam2924OpenMr. J. C. Eckhold, Director, Automotive Safety Office, Ford Motor Company, The American Road, Dearborn, MI 48121; Mr. J. C. Eckhold Director Automotive Safety Office Ford Motor Company The American Road Dearborn MI 48121; Dear Mr. Eckhold:#This is in response to your letter of August 29 1978, requesting an interpretation of Federal Motor Vehicle Safety Standard No. 101-80. The answers to your specific questions are as follows:#(1) You requested an interpretation that a single telltale which monitors both the oil pressure and coolant temperature gauges could be identified by the word 'Engine.' You indicated that it has been Ford's practice to combine the monitoring of these two functions into a single telltale because the response by the driver to either malfunction is the same. The standard does not require that any of the displays listed in S5.1 be provided or that two or more displays, if provided, be provided separately. It is the interpretation of the NHTSA that the multipurpose telltale which monitors the two functions specified above may be identified by the word 'Engine.'#(2) You asked whether the NHTSA intended that the display identification requirements of FMVSS 208 would be met by use of the symbol required by FMVSS 101-80. The answer is no. However, the agency will issue shortly a notice which will provide for the use of the FMVSS 101-80 symbol for the purposes of that standard and those of FMVSS 208.#(3) You asked that the identification requirements of FMVSS 105-75 be deleted from that standard and those in FMVSS 101-80 be retained. No conflict exists between the two standards. Nevertheless, we will address this issue in the same notice mentioned in the immediately preceding paragraph.#Sincerely, Joseph J. Levin, Jr., Chief Counsel; |
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ID: aiam0919OpenMr. W. G. Milby, Project Engineer, Blue Bird Body Company, Fort Valley, GA 31030; Mr. W. G. Milby Project Engineer Blue Bird Body Company Fort Valley GA 31030; Dear Mr. Milby: This is in response to your letter of October 30, 1972, in which yo raise a number of questions regarding Standard 217, Bus Window Retention and Release. I have numbered my answers to correspond with the numbering of your questions.; 1. You assume that when two latches requiring separate forc applications are used on a single exit, under S5.3.2 each latch mechanism may require forces less than or equal to the magnitudes specified in S5.3.2(a)(3) and (b)(3). Your assumption is correct.; 2. You state that the torque value 20 inch-pounds in S5.3.2(a)(3) i too low and suggest that it be raised to 225 inch-pounds. The problem to which you refer will be dealt with in an amendment to Standard 217 which is presently being prepared.; 3. You ask for a definition of the term reach distances used in S5.4 The term refers to the space envelopes (the shaded areas) in the Figures accompanying the standard. All movements required to release and open the emergency exits must occur within these space envelopes.; 4. You assume that the legibility requirements of S5.5.2 are to be me when the normal night time illumination is in the ON' position. This is correct.; 5. You ask for a clarification of Figures 1 and 2 to clarify th location of the bus wall in relation to the seat. The amendment currently being prepared will clarify the figures in a manner which should answer your question.; 6. You request a clarification of Figure 3A to indicate the floor an wall of an upright bus and the wall and roof of an overturned bus. The amendment currently being prepared will clarify the figures in a manner which should answer this question.; 7. You describe a horizontally hinged rear emergency window with tw latches at the bottom of the window spaced horizontally 53 3/8 inches apart. You ask if the 53 3/8 inch latch spacing is permitted if the exit you describe meets the requirements of Standard 217 in all other respects. The answer to your question is yes.; Sincerely, Richard B.Dyson, Assistant Chief Counsel |
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ID: aiam4059OpenMr. E. Ishizu, Executive Vice President, Hino Motors (U.S.A.) Inc., 200 Park Avenue, Suite 4114-12, New York, NY 10166; Mr. E. Ishizu Executive Vice President Hino Motors (U.S.A.) Inc. 200 Park Avenue Suite 4114-12 New York NY 10166; Dear Mr. Ishizu: This responds to your letter asking about compliance of a propose seating design with Federal Motor Vehicle Safety Standard No. 207, *Seating Systems*. We apologize for the delay in our response.; By way of background information, the National Highway Traffic Safet Administration does not grant approval of motor vehicles or motor vehicle equipment. Under the National Traffic and Motor Vehicle Safety Act, it is the responsibility of the manufacturer to ensure that its vehicles or equipment comply with applicable requirements. The following represents our opinion based on the facts provided in your letter.; According to your letter, you are considering installing a folding sea between the driver's and assistant seats in class 6 and 7 trucks. When the seat back is folded down, the back of the seat can be used as a console box. When the seat back is raised, the seat back is 'automatically locked by the pivot of turning hinge lowering along the guide groove by the weight of the seat back.' To fold the seat back after it has been locked, one must lift the seat back manually, thereby raising the pivot, in order to release the folding lock. You asked whether the seat complies with requirements of section S4.3 of the standard.; Section S4.3 of Standard No. 207 states: >>>Except for a passenger seat in a bus or a seat having a back that i adjustable only for the comfort of its occupants, a hinged or folding occupant seat or occupant seat back shall be equipped with a self-locking device for restraining the hinged or folding seat or seat back and a control for releasing that restraining device.<<<; As discussed below, your proposed seat does not appear to meet sectio S4.3's requirement for a control that releases the restraining device for hinged or folding seats or seat backs. The purpose of that requirement is to ensure that occupants in seats located behind folding seats are able to exit the vehicle.; Section S4.3 requires that your seat: (1) be equipped with self-locking device for restraining the folding seat back, and (2) have a specific control for releasing that restraining device. Your seat appears to meet the first of these requirements, since the seat back is locked automatically when the seat back is raised. However, your seat does not appear to have a specific control for releasing the restraining device. In order to release the restraining device, one must lift the seat back by hands and raise the pivot of the hinge for releasing the folding lock. Standard No. 207 requires a specific control for releasing the restraining device, such as a knob that one can turn or a lever that one can lift.; We recognize, based on the drawing provided with your letter, tha there would be no seats, i.e., no designated seating positions or auxiliary seating accommodations, behind your proposed folding seat. Therefore, the requirement for a specific control to release the restraining device does not appear to be relevant for your proposed design. However, as currently drafted, section S4.3 does not include an exception for such seats. In light of your letter, we plan to initiate rulemaking to propose such an exception. Until the issue is resolved by rulemaking, we will not enforce section S4.3's requirement for a specific control that releases the restraining device for hinged or folding seats or seat backs in vehicles where there are no seats behind the folding seat or seat back.; Sincerely, Erika Z. Jones, Chief Counsel |
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ID: aiam3266OpenMr. Robert A. Eddy, Manager, Quality Assurance, McCreary Tire & Rubber Company, Indiana, PA 15701; Mr. Robert A. Eddy Manager Quality Assurance McCreary Tire & Rubber Company Indiana PA 15701; Dear Mr. Eddy: This is in response to your letter of March 7, 1980, asking whethe ASTM E501 and E524 tires must be graded in accordance with the Uniform Tire Quality Grading (UTQG) Standards (49 CFR 575.104). You state that these tires are manufactured in limited quantities as standards for traction testing and are not manufactured for general highway use. It is the National Highway Traffic Safety Administration's understanding that these tires are used only on a test trailer designed for use in skid testing.; The UTQG regulation applies to new pneumatic tires for use on passenge cars (49 CFR 575.104(c)(1)). Thus, ASTM E501 and E524, which are manufactured solely for use on a traction test trailer, would not fall within the application of the UTQG Standards.; Sincerely, Frank Berndt, Chief Counsel |
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ID: aiam3773OpenMr. Austin Basham, Director, Motor Vehicle Division, Transportation Department, Manuel Lujan Senior Building, Santa Fe, New Mexico 87503; Mr. Austin Basham Director Motor Vehicle Division Transportation Department Manuel Lujan Senior Building Santa Fe New Mexico 87503; Dear Mr. Basham: On April 9, 1982, the National Highway Traffic Safety Administratio (NHTSA) approved New Mexico's odometer disclosure statement for use in lieu of a separate Federal form.; Pursuant to a recent inquiry, I have found that New Mexico is no longe using this approved form. New Mexico's current Certificate of Title does not satisfy the requirements of 49 CFR Part 580 and, therefore, the Federal odometer disclosure statement must be used.; If New Mexico wants to use its Certificate of Title in lieu of separate Federal form, it must include a statement which refers to State or Federal law, and must include a space for the purchaser's signature. NHTSA considers this signature to be essential because it is an acknowledgment that the purchaser was aware of the mileage. The purchaser, when he signs the document, is prevented from later alleging that he was not informed of the mileage or that the mileage was different from that appearing on the title. Additionally, Part 580.4(c) requires that three statements be included on the odometer disclosure statement. New Mexico's title certificate fails to include the first of these three. While it does provide a space for the odometer mileage, it fails to include a statement, as required by this section, stating that the transferor 'certif ies that to the best of his knowledge the odometer reading reflects the actual miles or kilometers the vehicle has been driven.'; It was suggested that New Mexico's Application for Vehicle Title an Registration may be used in lieu of a Federal odometer disclosure statement. This form, however, does not include all required information. The odometer disclosure statement must include the information specified in 49 CFR S 580.4(a)-(e). Alternatively, in accordance with 49 CFR S580.4(f), a 'State certificate of title or such other ownership document' may be used as a substitute and need only include information required by (a), (b), (c) and (e). An application for vehicle title and registration does not constitute an ownership document, and the application fails to include all information specified in Part 580.4(a)-(e).; Sincerely, Frank Berndt, Chief Counsel |
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ID: aiam2861OpenMr. James Tydings, Specifications Engineer, Thomas Built Buses, Inc., 1408 Courtesy Road, P.O. Box 2450, High Point, NC 27261; Mr. James Tydings Specifications Engineer Thomas Built Buses Inc. 1408 Courtesy Road P.O. Box 2450 High Point NC 27261; Dear Mr. Tydings: This responds to your August 21, 1978, letter asking whether you ar permitted under Standard No. 217, to place the emergency exit sign at the bottom of a rear emergency window exit.; The National Highway Traffic Safety Administration has permitted th use of the emergency exit sign to be on the top half of rear emergency doors. This has permitted the sign to be located just below the glass on the rear emergency door. Although your location of the exit sign is not on the top of the rear emergency window exit, its location is similar to the location of the exit sign on a rear emergency door. Since the location of the sign is on the emergency window exit and is within the top half of the bus, the agency has determined that this location complies with the requirement.; Sincerely, Joseph J. Levin, Jr., Chief Counsel |
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ID: aiam3289OpenMr. Robert Slagle, Parts Manager, Brown Motors Volkswagen, 5 West 18th Street at National City Boulevard, National City, CA 92050; Mr. Robert Slagle Parts Manager Brown Motors Volkswagen 5 West 18th Street at National City Boulevard National City CA 92050; Dear Mr. Slagle: This responds to your recent letter requesting information concernin the Federal requirements that would be applicable to the manufacture and installation of auxiliary diesel fuel tanks in passenger cars. I am enclosing a copy of a letter of interpretation the agency issued last August which discusses the general implications of such installations under Federal law.; Your letter asked whether it will be necessary for you to crash tes vehicles that have the auxiliary tanks installed. As indicated in the enclosed interpretation, if the tank is added to a new vehicle prior to its first purchase for purposes other than resale, the person making the alteration will have to certify that the vehicle continues to be in compliance with all Federal motor vehicle safety standards, including Standard No. 301-75. The National Traffic and Motor Vehicle Safety Act requires a manufacturer (including an alterer) to exercise due care to assure that a vehicle it certifies is in fact in compliance with all safety standards (15 U.S.C. 1397). It is up to the manufacturer to determine how he will establish due care and, in this case, whether he will crash test a vehicle or use some other method to ensure compliance of the vehicle. The test procedures in Safety Standard No. 301-75 are not obligatory, only the performance requirements. The test procedures do, however, state how the agency will test a vehicle to determine compliance.; In answer to your question number 4, I can state that it will not b necessary for you to crash test each vehicle which has a tank installed in order to establish due care. If by your question you meant one car of each car 'model,' once again, it is up to the manufacturer how he establishes due care.; In answer to your question number 3, the information contained in th enclosed interpretation includes discussions of all the Federal safety requirements that would be applicable to your company's activities. There may, of course, be other general Federal laws regarding the conducting of a business which would be pertinent. For example, Federal Trade Commission regulations regarding advertising could affect your activities. You are probably aware of these general regulations, however, since you are already an established business enterprise.; Regarding your final question, all vehicle manufacturers, both domesti and foreign, have performed crash tests to determine compliance with Safety Standard No. 301-75. Since your company is a Volkswagen dealership, I suggest you contact Volkswagen regarding its compliance testing program for Safety Standard No. 301-75.; If you have any further questions after reviewing this information please contact Hugh Oates of my staff (202-426-2992).; Sincerely, Frank Berndt, Chief Counsel |
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ID: aiam3323OpenDouglas Middleton, U.S.A.A., P.O. Box 33400, San Antonio, TX 78233; Douglas Middleton U.S.A.A. P.O. Box 33400 San Antonio TX 78233; Dear Mr. Middleton: This is in response to your telephone call of August 6, 1980, to Kath DeMeter of my staff concerning odometer information on state certificates of title.; The following states have odometer statements on their motor vehicl titles that are consistent with the requirements of the federal law:; >>>Maryland, Ohio, Massachusetts, Pennsylvania, Michigan, Hawaii Minnesota, New York, North Dakota<<<; In addition, the following states submitted titles to the agency askin for approval but had inacceptable statements. Each was informed that if they supplied certain additional information their titles would be in conformance. We do not know whether that information was included on the titles:; >>>North Carolina, Virginia, Delaware, Washington, South Dakota, Utah Wisconsin<<<; In order to spare states the burden of an approval process the agenc has indicated that certain variations from the Federal form are acceptable. In the Federal Register notice of August 1, 1977, which amended the disclosure regulation, we gave examples of shortened forms that would be acceptable. A state title can be considered to be approved for use as a full disclosure statement if it varies from the Federal form in only those aspects noted in the August 1 notice, a copy of which is enclosed.; If you have any further questions, please do not hesitate to write. Sincerely, John Womack, Assistant 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.