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: aiam5397OpenMr. Thomas D. Turner Manager, Engineering Services Blue Bird Body Company P.O. Box 937 Fort Valley, GA 31030; Mr. Thomas D. Turner Manager Engineering Services Blue Bird Body Company P.O. Box 937 Fort Valley GA 31030; Dear Mr. Turner: This responds to your petition for rulemaking date May 31, 1994. Your petition concerns the following requirement in S5.3.3.2 of Standard No. 217, Bus Emergency Exits and Window Retention and Release: In the case of windows with one release mechanism, the mechanism shall require two force applications to open. A similar requirement is included in S5.3.3.3 for emergency roof exits. Your petition states: The requirement for two force applications to open a single release mechanism is new and unproven and in our opinion is not in the best interest of safety. NHTSA agrees that the sentence in question is susceptible to the reading you gave it. So read, this sentence imposes a requirement not intended by the agency. To avoid such unintended readings, the agency should have worded the sentence as follows: In the case of windows with one release mechanism, the exit shall require two force applications to open. The agency will issue a corrective notice in the future to make this change. Until the notice is issued, we will not take enforcement action against a manufacturer so long as a window or roof exit with one release mechanism requires two force applications to open the exit. I hope you find this information helpful. If you have any other questions, please contact Mary Versailles of my staff at this address or by phone at (202) 366-2992. Sincerely, John Womack Acting Chief Counsel; |
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ID: aiam2452OpenMr. W. G. Milby, Manager, Engineering Services, Blue Bird Body Company, P.O. Box 937, Fort Valley, GA 31030; Mr. W. G. Milby Manager Engineering Services Blue Bird Body Company P.O. Box 937 Fort Valley GA 31030; Dear Mr. Milby: This is in response to your letter of November 3, 1976, in which yo ask whether the label Emergency Door' when placed on the glass near the top of a school bus emergency exit, complies with the requirements of Standard No. 217, *Bus Window Retention and Release*.; The positioning of this label will be regulated by S5.5.3 of Standar No. 217 in the case of school buses manufactured on or after April 1, 1977. That section, as it pertains to the location of the designation Emergency Door,' states in part that the designation shall be ...located at the top of or directly above the emergency exit...' The markings you describe, located at the top of the glass of the emergency door, would appear to be in compliance with the location requirements of S5.5.3 of Standard No. 217 (effective April 1, 1977).; Sincerely, Frank A. Berndt, Acting Chief Counsel |
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ID: aiam0195OpenMr. Edward P. Robinson, Alba Tire Company, 422 Lead Avenue, Southwest, Albuquerque, New Mexico 87101; Mr. Edward P. Robinson Alba Tire Company 422 Lead Avenue Southwest Albuquerque New Mexico 87101; Dear Mr. Robinson: #Thank you for your letter of November 24, 1969, t the National Highway Safety Bureau, concerning our proposed retreaded tire standard. #I appreciate you sending your thoughts on tire safety to our attention since we make a point of being as familiar as possible with the present state-of-the-art of all aspects to tire safety. #The Federal Motor Vehicle Safety Standards do not apply to tires manufactured exclusively for off-road competitive use or to tires retreaded exclusively for off-road competitive use. You are cautioned however, that if the tires are sold for 'street use', then these racing tires will be covered by the proposed standards and would be subject to the requirements. #Sincerely, Charles A. Baker, Office of Standards on Accident Avoidance, Motor Vehicle Safety Performance Service; |
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ID: aiam2901OpenMr. William Shapiro, Manager, Regulatory Affairs, Product Planning and Development, Volvo of America Corporation, Rockleigh, NJ 07647; Mr. William Shapiro Manager Regulatory Affairs Product Planning and Development Volvo of America Corporation Rockleigh NJ 07647; Dear Mr. Shapiro:#This is in response to your letter of September 20 1978, requesting an interpretation of Federal Motor Vehicle Safety Standard No. 101-80, *Controls and Displays*.#Specifically, you asked whether the km/h label on Volvo speedometers could appear in upper case letters instead of the lower case letters appearing in Table 2 of the standard. The answer is yes.#Section 5.2.3 of the standard provides that 'any such display for which no symbol is provided in Table 2 shall be identified by the word or abbreviation shown in column 3.' There is no requirement that the identifying words or abbreviations be in the same type face, type size, or case as those printed in the Federal Register. Therefore, as long as the abbreviations are the same as those appearing in Table 2 and are visible, no problem arises because Volvo wishes to use upper case, rather than lower case letters.#Sincerely, Joseph J. Levin, Jr., Chief Counsel; |
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ID: aiam3613OpenMr. James R. Bede, President, Bede Design Inc., 901 E. Orchard Street, Mundelein, IL 60060; Mr. James R. Bede President Bede Design Inc. 901 E. Orchard Street Mundelein IL 60060; Dear Mr. Bede: This is in reply to your letter of September 29, 1982, asking for a interpretation that your modified motorcycle is a 'motorcycle' under the Federal Motor Vehicle Safety Standards. In addition to the standard motorcycle configuration of a single front and rear wheel, your design incorporates two small wheels in outrider positions, both of which hold the vehicle at rest, but which, in motion, do not touch the ground simultaneously. The purpose of the wheels is to add stability so that in a left turn the left outrider wheel will touch the ground, and in a right turn, the right wheel.; This configuration appears to meet the definition of 'motorcycle contained in 49 CFR 571.3(b) as a machine 'designed to travel on not more than three wheels in contact with the ground.' Although the vehicle rests on four wheels, it travels on only two or three depending upon whether it is proceeding in a straight direction or in a turn.; We appreciate your interest in motorcycle safety. Sincerely, Frank Berndt, Chief Counsel |
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ID: aiam3243OpenMr. Don Gerkin, Product Engineer, Cosco Home Products, 2525 State Street, Columbus, IN 47201; Mr. Don Gerkin Product Engineer Cosco Home Products 2525 State Street Columbus IN 47201; Dear Mr. Gerkin: This responds to your letter of January 23, 1980, to Mr. Vladisla Radovich concerning Standard No 213, *Child Restraint Systems*. Your letter was forwarded to my office for reply.; You asked whether a crotch strap that is 'permanently attached to movable shield can be attached during the 20 mph test required for child restraint systems that have fixed or movable shields (sic). Sections S6.1.2.3.1(c) and S6.1.2.3.2(b) provide that, in the 20 mph tests, the child restraint belts are not to be attached unless 'they are an integral part of the fixed or movable shield.' The agency used the word 'integral' in its ordinary sense to mean something that is 'formed as a unit with another part.' (Webster's New Collegiate Dictionary, 1977). A crotch strap that is permanently affixed to the shield is formed as a unit with the shield, and therefore, can remain attached during the test.; You also asked, whether, if the movable shield 'were designed in such way that moving it into position for use it automatically locked in that position, and a child was unable to unlock it', would the 20 mph test be conducted with the shield locked into place? Sections S6.1.2.3.1(c) and S6.1.2.3.2(b) provide that each movable surface is to be positioned in accordance with the manufacturer's instructions. Therefore, as long as your instructions explain how to lock the movable shield, it can be locked into place prior to the testing.; If you have any further questions, please let me know. Sincerely, Frank Berndt, Chief Counsel |
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ID: aiam4586OpenMr. M.J. Yoon Director In-One Development Corp. 2nd Floor, Gukdong Building 3-Ga Chungmoo-Ro Jung-Gu Seoul, Korea; Mr. M.J. Yoon Director In-One Development Corp. 2nd Floor Gukdong Building 3-Ga Chungmoo-Ro Jung-Gu Seoul Korea; "Dear Mr. Yoon: This responds to your letter to Mr. Kratzke, askin whether a vehicle you are developing for a client would be classified as a passenger car or a multipurpose passenger vehicle for the purposes of the Federal motor vehicle safety standards. I am pleased to be able to explain our law and regulations for you. I regret the delay in responding. At the outset, I would like to make clear that the National Traffic and Motor Vehicle Safety Act (15 U.S.C. 1381 et seq.) places the responsibility for classifying a particular vehicle in the first instance on the vehicle's manufacturer. For this reason, NHTSA does not approve or endorse any vehicle classifications before the manufacturer itself has classified a particular vehicle. NHTSA may reexamine the manufacturer's classification during the course of any enforcement actions. We will, however, tentatively state how we believe we would classify this vehicle for the purposes of our safety standards. It is important that you understand that these tentative statements of classification are based entirely on our understanding of the information presented in your letter to us. These tentative statements about the vehicle's classification may change after NHTSA has had an opportunity to examine the vehicle itself or otherwise acquire additional information about the vehicle. With those caveats, we believe that the vehicle referenced in your letter could be classified as a multipurpose passenger vehicle for the purposes of our safety standards. The term 'multipurpose passenger vehicle' is defined in 49 CFR /571.3 as 'a motor vehicle with motive power, except a trailer, designed to carry 10 persons or less which is constructed either on a truck chassis or with special features for occasional off-road operation.' In your letter, you describe the vehicle as having 4-wheel drive. Additionally, the approach and departure angles and the running clearance dimensions for this vehicle show that it has high ground clearance. The combination of 4-wheel drive and high ground clearance would be considered 'special features for occasional off-road operation.' Hence, it appears to us that this vehicle could be classified as a multipurpose passenger vehicle. You also asked for a copy of the criteria for classifying vehicles for purposes of the safety standards. All of our classification definitions are set forth in 49 CFR /571.3. The information sheet I have enclosed explains how to obtain a copy of this and all of our other regulations, and provides other information relevant to new motor vehicle manufacturers. I have also enclosed a copy of our proposal for a new vehicle classification system for the safety standards. I hope this information is helpful. Please let me know if you have any further questions or need additional information. Sincerely, Erika Z. Jones Chief Counsel Enclosures /"; |
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ID: aiam0896OpenMr. Charles P. Madigan, Sunspot Products Company, 25162 Mound Road, Warren, MI, 48091; Mr. Charles P. Madigan Sunspot Products Company 25162 Mound Road Warren MI 48091; Dear Mr. Madigan: This letter is in response to your letter to James H. Wakelin, forme Assistant Secretary of Commerce about the vertical flammability test cabinet used in Federal Motor Vehicle Safety Standards.; Although our Fire Technology Division is active in developing tests t measure the flammability of fabrics, we do not have jurisdiction in the area of motor vehicles. Nevertheless, we are happy to forward a copy of your letter to Mr. Joseph F. Zemaitia, Safety Standards Engineer, Office of Crashworthiness, Motor Vehicle Program, National Highway Traffic Safety Administration, Department of Transportation, Room 5319J, 400 7th Street, S.W., Washington, D.C. 20590.; We hope that this action is helpful to you. Sincerely, F. Karl Willenbrock, Director, Institute for Applie Technology; |
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ID: aiam1784OpenMr. Richard L. Hoover, Executive Vice President, Flash-Patrol Safety Equip. Pro., P.O. Box 194, Chenoa, Illinois 61726; Mr. Richard L. Hoover Executive Vice President Flash-Patrol Safety Equip. Pro. P.O. Box 194 Chenoa Illinois 61726; Dear Mr. Hoover: This is in response to your letter of January 17, 1975, asking whethe your 'STASH-FLASH' barricade is permissible for emergency and other use.; The National Highway Traffic Safety Administration neither approved no disapproved individual devices. Rather, we establish performance standards for special types of motor vehicle equipment. As Federal Motor Vehicle Safety Standard 125, dealing with warning devices, does not apply to devices with self-contained energy sources, your device would not fall under the requirements of that standard, and may be produced by you without regard to the safety standards.; I trust this information is useful to you. Yours truly, Richard B. Dyson, Assistant Chief Counsel |
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ID: aiam4569OpenMr. Leonard M. Perkins 213 S. Pleasant Prescott, AZ 86303; Mr. Leonard M. Perkins 213 S. Pleasant Prescott AZ 86303; Dear Mr. Perkins: Secretary Burnley has asked me to respond to you letter of September 7, 1988, with respect to your lighting device. In essence, this is a center high-mounted stop lamp, with turn signal lamps adjacent to it. You believe that high-mounted turn signals 'joined with the rear window brake light should have a dramatic effect on rear and side collisions', but you have been told that 'this conception is at present illegal.' Paragraph S4.4 of Federal Motor Vehicle Safety Standard No. 108 states that 'no high-mounted stop lamp shall be combined with any other lamp or reflective device.' We interpret this as prohibiting lamps or reflective devices that share a single lens or compartment with the center highmounted lamp. Your device shows lamps adjacent to the center highmounted lamp but not combined with it. Therefore, your device is not prohibited by that paragraph of the standard if you wish to market this device as original equipment. The next question to ask is whether it impairs the effectiveness of required lighting equipment (paragraph S4.1.3), principally the center stoplamp. For example, if the yellow turn signals were too bright or if the color of the turn signal were red, these lamps might 'impair the effectiveness' of the center stoplamp. However, this is a determination to be made, in the first instance, by the manufacturer of the vehicle who must certify compliance with Standard No. 108. If you wish to sell your device in the aftermarket, it is acceptable under Federal law if its installation does not adversely affect the operation of motor vehicle equipment installed in accordance with a Federal motor vehicle safety standard so that the equipment would no longer comply with the standard. Assuming that the installation does not have this effect, the legality of installing or using such a device must then be determined according to the laws of any State in which a vehicle so equipped is registered or operated, and these auxiliary lamps must comply with any State requirements. We cannot advise you on State laws. One source of advice is the American Association of Motor Vehicle Administrators, 4600 Wilson Blvd., Arlington, Va. 22203. Sincerely, Erika Z. Jones 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.