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: aiam2659OpenMr. James Tydings, Thomas Built Buses, Inc., 1408 Courtesy Road, P.O. Box 2450, High Point, NC 27261; Mr. James Tydings Thomas Built Buses Inc. 1408 Courtesy Road P.O. Box 2450 High Point NC 27261; Dear Mr. Tydings: This responds t your August 19, 1977, letter asking whether Standar 217, *Bus Window Retention and Release*, allows the identification of the rear emergency door located anywhere on the top half of the door.; The standard in S5.5.3 requires the emergency door identification to b located at the top of or directly above the emergency exit....' The National Highway Traffic Safety Administration interprets this requirement to mean that the emergency door label must be located on the top half of the door or directly above the door. The label location as depicted in the picture you enclosed with your letter appears to comply with the requirements of S5.5.3.; Sincerely, Joseph J. Levin, Jr., Chief Counsel |
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ID: aiam0664OpenMr. S. A. Heenan, Director, Research & Development, Stimsonite Division, Amerace - Esna Corporation, 3445 North Kimball Avenue, Chicago, IL 60618; Mr. S. A. Heenan Director Research & Development Stimsonite Division Amerace - Esna Corporation 3445 North Kimball Avenue Chicago IL 60618; Dear Mr. Heenan: In your letter of February 4 to Mr. Schneider you discussed difference between SAE Standard J594d, March 1967, *Reflex Reflectors,* and its successor J594e, March 1970. You asked 'whether relief can be granted from the unnecessary specular restriction appearing in Federal Motor Vehicle Safety Standard No. 108 because of its inclusion of J594d rather than J594e.'; We have reviewed your letter and the Administrator has determined tha the issue you raised merits initiation of rulemaking. I enclose a copy of a notice proposing an amendment to Standard No. 108 to substitute SAE J594e as the referenced requirement for reflex reflectors.; Yours truly, Richard B. Dyson, Assistant Chief Counsel |
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ID: aiam5466OpenMr. R. F. Wareham Technical Director Total Vehicle Security, Ltd. 1 Friarn Lawn Bridgwater Somerset TA6 3LL England; Mr. R. F. Wareham Technical Director Total Vehicle Security Ltd. 1 Friarn Lawn Bridgwater Somerset TA6 3LL England; Dear Mr. Wareham: We have received your letter of December 9, 1994, t John Womack, the Acting Chief Counsel who responded to David Lee on January 26, 1993. This will confirm that his opinion regarding the 'Third Brake Light Conditions Sensor' remains the official position of this agency. We shall be pleased to meet with you when you come to Washington late in January. You may phone Taylor Vinson of this Office to make arrangements (202- 366-5263). We will be particularly interested in learning more about how the device 'will be marketed as a D.I.Y. installation by the car owner.' Sincerely, Philip R. Recht Chief Counsel; |
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ID: aiam2209OpenMr. Lonnie Goddard, Northern Coach, Inc., Box 190, Auburndale, WI 54412; Mr. Lonnie Goddard Northern Coach Inc. Box 190 Auburndale WI 54412; Dear Mr. Goddard: I am writing to confirm your telephone conversation of February 25 1976, with Mark Schwimmer of this office, concerning the certification of school buses.; As Mr. Schwimmer explained, this agency does not certify or otherwis issue advance approvals of motor vehicles or motor vehicle equipment. Certification, under the applicable law and regulations, must be done by the vehicle manufacturer, including a final-stage manufacturer such as you. Your certification obligation, as a final stage manufacturer of school buses, is met if you fulfill the requirements of 49 CFR Part 567, with which I understand you are already familiar.; An information sheet entitled 'Where to Obtain Federal Motor Vehicl Safety Standards and Regulations' is enclosed for your convenience. Please write if we can be of any further assistance.; Yours truly, Richard B. Dyson, Assistant Chief Counsel |
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ID: aiam0234OpenMr. Donald F. Clausen, Route 4, Menomonie, WI 54751; Mr. Donald F. Clausen Route 4 Menomonie WI 54751; Dear Mr. Clausen: Your postcard of March 9, 1970, to the Chicago Regional Office of th Interstate Commerce Commission has been forwarded to this office by Mr. F. B. Farrell, Regional Administrator for Region 4, Federal Highway Administration. In your card, you request a copy of I.C.C. requirements for a camping trailer you intend to build.; The I.C.C. regulations concerning equipment for trailers are no administered by the Bureau of Motor Carrier Safety, Federal Highway Administration, Department of Transportation. These regulations apply only to vehicles used in interstate commerce for commercial purposes. If you intend to build a camping trailer for your personal use, these regulations would not be applicable to it. Should this not be the case, however, I am enclosing a copy of these requirements for your information.; Federal motor vehicle safety standards, which are issued by th National Highway Safety Bureau pursuant to National Traffic and Motor Vehicle Safety Act of 1966, do apply to manufacturers of camping trailers which will be towed on public highways. At present, the only Federal standard applicable to trailers is Standard No. 108, 'Lamps(sic) Reflective Devices and Associated Equipment', and your trailer must conform to its requirements. I enclose a copy of this standard as amended, and a copy of the above mentioned Act.; I suggest you also consult state and local authorities for possibl other requirements which they may impose on trailers. If I may be of further assistance, please contact me.; Sincerely, Rodolfo A. Diaz, Acting Associate Director, Motor Vehicl Programs; |
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ID: aiam5036OpenMr. Eugene Welker 774 Harbor Island Clearwater, FL 34630; Mr. Eugene Welker 774 Harbor Island Clearwater FL 34630; "Dear Mr. Welker: This responds to your letter about a mirror syste designed to improve a driver's view of areas behind a motor vehicle. You explained that a 35' vertical post would be bolted near a vehicle's rear bumper. This would result in a mirror being located a few inches above the top rear window stop light and facing forward at a 45 angle. You asked whether such a device would be legal. The following discussion and the enclosed information sheet, 'Information for New Manufacturers of Motor Vehicles and Motor Vehicle Equipment,' explain your responsibility under NHTSA's regulation. By way of background information, the National Highway Traffic Safety Administration (NHTSA) does not approve, endorse, or certify motor vehicles or motor vehicle equipment. Under the National Traffic and Motor Vehicle Safety Act ('Safety Act'), the manufacturer is responsible for certifying that its vehicles or equipment comply with applicable Federal motor vehicle safety standards. The Safety Act requires that these safety standards establish minimum levels of performance for vehicles or equipment. Once the performance level has been established, vehicle or equipment manufacturers are free to choose any means they wish to achieve the required level of performance. NHTSA has exercised its authority to establish performance requirements for new vehicles in Standard No. 111, Rearview Mirrors (49 CFR 571.111, copy enclosed). Standard No. 111 establishes performance and location requirements for rearview mirrors installed in any new vehicle. This means that the vehicle manufacturer must certify that each vehicle it manufactures complies with the specified requirements. Standard No. 111 requires that passenger cars be equipped with an inside rearview mirror and a driver's side outside rearview mirror that provide the field-of-view specified in S5.1.1. A passenger's side outside rearview mirror is required in situations where the inside rearview mirror does not provide the specified field-of-view. Additional requirements for other vehicle types are set forth in S6, S7, and S8. No provision in the Standard specifies requirements for a mirror that attaches to the vehicle's rear bumper. Accordingly, a mirror like yours would not be prohibited from being installed on any vehicle by the current requirements in Standard No. 111. Accordingly such a mirror would be permitted, but only as a supplement to the required mirrors. In installing the mirror, one must take care to avoid obscuring the vehicle's lighting devices, including the center highmounted stop lamps (CHMSL). Please be aware that NHTSA does not regulate vehicles while they are in use. The American Association of Motor Vehicle Administrators, 4600 Washington Blvd, Arlington, VA 22203 may be able to advise you about the laws of the individual States related to the use of equipment such as your own. I hope this information is helpful. If you have any further questions about NHTSA's safety standards, please feel free to contact Marvin Shaw of my staff at this address or by telephone at (202) 366-2992. Sincerely, Paul Jackson Rice Chief Counsel"; |
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ID: aiam1075OpenMr. John White, Michelin Tire Corporation, Technical Division, 2500 Marcus Avenue, Lake Success, NY 11040; Mr. John White Michelin Tire Corporation Technical Division 2500 Marcus Avenue Lake Success NY 11040; Dear Mr. White: This is to confirm your conversation with Mr. Schmeltzer of this offic in which he informed you that the Regrooved Tire regulation (49 CFR Part 569) does not prohibit the use of branding to meet its labeling requirements. the language in section 569.9 which requires the word 'regroovable' to be 'molded into or onto' tires designed for regrooving was intended to include any method, such as branding, that would leave the required information sunk into or raised upon the tire surface.; Yours truly, Richard B. Dyson, Assistant Chief Counsel |
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ID: aiam3048OpenHonorable Daniel K. Akaka, 415 Cannon Building, House of Representatives, Washington, DC 20515, Attention: Mr. Pat McGarey; Honorable Daniel K. Akaka 415 Cannon Building House of Representatives Washington DC 20515 Attention: Mr. Pat McGarey; Dear Mr. Akaka: This responds to your June 21, 1979, telephone request asking ho automobile dealers can determine when they must sell school buses as opposed to regular vans.; The key factors in making this determination are the purpose for whic the vehicle will be used and the passenger carrying capacity of the vehicle. The National Highway Traffic Safety Administration (NHTSA) issued the school bus safety standards in response to the Motor Vehicle and Schoolbus Safety Amendments of 1974 (Pub. L. 93-492). In defining 'schoolbus', Congress drew upon NHTSA's definition of 'bus', i.e., any motor vehicle, including a van, designed to carry more than 10 persons. Congress stated that the term 'schoolbus' means 'a passenger motor vehicle which is designed to carry more than 10 passengers ... and which the Secretary determines is likely to be significantly used for the purpose of transporting ... students to or from school or events related to such schools.' The NHTSA concluded from this mandate that any vehicle that is a bus and will be used on a regular and recurring basis to transport school children must comply with school bus safety standards. To effect this conclusion, the agency issued a definition of 'schoolbus' which is 'a bus that is sold or introduced in interstate commerce, for purposes that include carrying students to or from school or related events....'; The effect of the 1974 amendments and the agency's definition is t require any new bus that is sold to transport school children on a regular basis to comply with the safety standards. Compliance is required whether a bus is used regularly to transport students 100 percent of the time or whether it regularly transports students only 10 percent of the time while otherwise transporting adults.; Sincerely, Frank Berndt, Chief Counsel |
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ID: aiam4277OpenMr. David A. White, Senior Safety Engineer, Grumman Olson, Post Office Box 2005, Sturgis, MI 49091; Mr. David A. White Senior Safety Engineer Grumman Olson Post Office Box 2005 Sturgis MI 49091; Dear Mr. White: This letter responds to your inquiry of November 17, 1986, asking thi agency to approve an alternate location for the certification label of a light duty truck your company intends to manufacture for the United States Post Office. Section 567.4 of the National Highway Traffic Safety Administration (NHTSA) regulations requires that a motor vehicle manufacturer affix a certification label to each vehicle it makes, and permits the manufacturer to place the label in any one of the places set out in that provision. If none of those locations is practicable, S567.4 directs the manufacturer to suggest an alternate place to affix the label, and to ask our approval for that alternative.; You explain in your letter that in the circumstances you describe, th S567.4 locations are impractical. First, you explain, the vehicle's sliding doors make the hinge pillar and door latch post and edge too small and irregularly shaped for a label. Second, if your company places the label on the inside of the sliding door, opening the door would hide the label. Third, you assert that the instrument panel is too small for a label.; You enclose a drawing to illustrate where your company intends to plac the certification label. According to your description, the certification label will be placed on a fixed panel behind the driver, and between the cab and the load compartment. This panel is one part of a three piece assembly of which the remaining two components are a center sliding door and a second fixed panel. You state that a person can see the certification label from the driver's area without moving any vehicle item.; In directing a manufacture to put its certification label in thos places set out in S567.4, NHTSA's purpose is to make these labels easy to see and read. Based on the information you supplied, the agency determines that for this particular design, installing the certification label as your company proposes will facilitate seeing and reading the label, while placing the label as specified in S567.4 may not be practicable or might interfere with those activities. Therefore, on the condition that your company's label complies in all other respects with S567.4, NHTSA grants your request to install the certification label on the forward side of the left hand bulkhead fixed panel.; Sincerely, Erika Z. Jones, Chief Counsel |
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ID: aiam1425OpenMr. Jim Lang, L and R Enterprises, P.O. Box 2201, Wichita Falls, Texas 76307; Mr. Jim Lang L and R Enterprises P.O. Box 2201 Wichita Falls Texas 76307; Dear Mr. Lang: This responds to your February 15, 1974, letter asking whether you installation of spotlights through the left A-pillar of passenger cars is subject to Standards 201 and 216.; Standard 201 does not apply to the instrument panel area on th driver's side from the left door to a longitudinal plane 3-1/4 inches to the right of the steering wheel. The left A pillar is within this excluded area.; Your drilling operation may effect roof strength an I have enclosed copy of Standard 216, our standard on roof crush resistance. Under the National Traffic and Motor Vehicle Safety Act of 1966, it is the responsibility of the person who manufactures or alters a vehicle to determine whether his vehicle meets the requirements.; Your business is subject to these requirements, however, only if yo qualify as an alterer of motor vehicles under 49 CFR 567.7, which is enclosed. The mounting of a spotlight by drilling the A-pillar is a 'non-readily attachable' alteration. Such an alteration would be subject to the S567.7 requirement only if you mount it 'before the first purchase of the vehicle in good faith for purposes other than resale.'; Yours truly, Richard B. Dyson, Assistant Chief Counsel |
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.