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: nht75-5.16OpenDATE: 08/07/75 FROM: AUTHOR UNAVAILABLE; Richard B. Dyson; NHTSA TO: Dunlop Tire and Rubber Corporation TITLE: FMVSR INTERPRETATION TEXT: This is in response to your letter of July 1, 1975 (NA-2637A), forwarded to us by the Tire Division, which requests comments on the issues raised by two letters from Mr. R. G. Clifton of Dunlop U.K. Mr. Clifton's first concern is with respect to the proper interpretation of section 159(2) of the 1974 amendments to the National Traffic and Motor Vehicle Safety Act (15 U.S.C. 1419). Section 159 provides that the definitions of "original equipment" and "replacement equipment" in section 159 may be changed "as otherwise provided by Regulations of the Secretary." This phrase does not mean that the definitions may be changed by any regulation, but rather that the definitions may be changed by a regulation implementing sections 151-60 of the 1974 amendments, to which the provisions of section 159 specifically apply. Therefore, a definition of "tire manufacturer" in a regulation issued pursuant to some other statutory provision has no effect on the definitions of "original equipment" and "replacement equipment" in section 159. No specific regulation has yet been issued by the National Highway Traffic Safety Administration (NHTSA) modifying the provisions of section 159, although such a regulation is currently under consideration. Mr. Clifton's second concern was that no amendments to Part 573 have been proposed in order to make tire and equipment manufacturers subject to defect reporting requirements, as required by the 1974 amendments. The NHTSA is preparing to issue proposed amendments to Part 573 which will reflect this requirement. Mr. Clifton's third concern, expressed in his letter of June 3, was that section 159(2) (D) of the 1974 amendments would make the motor vehicle manufacturer totally responsible for the original equipment tires on his vehicles. Although section 159 places the legal responsibility for notification and remedy of safetyrelated defects in original equipment on the vehicle manufacturers, it does not lessen the obligation of the tire manufacturers to ensure that their tires contain no safety-related defects. Tire manufacturers do have an obligation to notify of and remedy defects in tires used as replacement equipment. We trust this has been helpful. If you have any further questions, please do not hesitate to write. |
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ID: nht94-3.91OpenTYPE: INTERPRETATION-NHTSA DATE: August 9, 1994 FROM: John Womack -- Acting Chief Counsel, NHTSA TO: Denise Davis TITLE: NONE ATTACHMT: Attached to letter 1/1/94 (EST) to "Whom It May Concern" from Denise Davis (OCC-9758) TEXT: Dear Ms. Davis: This responds to your letter asking for help in a matter involving window tinting on your car. I apologize for the delay in responding. You explain in your letter that you asked a window tinting store for a sticker showing that the tint on your windows met Georgia law. The store informed you that it cannot issue you a sticker because your windows only allow 20 percent sunlight through, and the new law requires 35 percent. To get a sticker, you would have to remove the tint, which you explain will be costly. You also state that your windows were tinted seven years ago when you purchased your car, and at the time you had your windows t inted, you were "not breaking any law." I regret that we cannot help you pay to have the tint removed. The primary purpose of this agency is to regulate the manufacture and sale of new motor vehicles and new motor vehicle equipment. We have no authority to provide funds to citizens to help t hem correct problems with their vehicles or equipment. Please bear in mind that the "35 percent" law was adopted by Georgia to regulate the operation of vehicles. Thus, we suggest that you contact the Georgia Department of Motor Vehicles for information about this matter. We appreciate your efforts to reduce the tint on your vehicle and are sorry that we are unable to assist you. If you have any other questions, please contact Mr. Marvin Shaw of my staff at (202) 366-2992. |
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ID: nht93-2.48OpenDATE: April 9, 1993 FROM: Lawrence Hufstedler -- Kesler Research Enterprises, LTD.; Raymond Kesler -- Kesler Research Enterprises, LTD. TO: John Womack -- Acting Chief Counsel, U.S. Department of Transportation, NHTSA TITLE: None ATTACHMT: Attached to letter dated 4-27-93 from John Womack to Lawrence Hufstedler and Raymond Kesler (A41; VSA 108(a)(2)(A); FMVSS 111) TEXT: We would like to thank you for the meeting of April 8, 1993, concerning the Advanced Technology Rear View Mirror Concept. We have been researching and developing this product since 1986. It was indeed a pleasure to come in to your office and introduce you to the concept as well as the actual hardware. Let us take a moment to also thank Mr. Marvin Shaw of your legal department for his guidance and legal expertise in helping us understand the governmental aspect of our improved concept. Also, Mr. Mike Perel from your Research and Development department for his input concerning federal testing procedures. Let us not forget Mr. Rich Van Iderstine and Mr. Pat Boyd, from the office of Rule making. They were able to guide us through positive and enlightening particulars in their area. During the meeting your agency representatives spoke of Federal Motor Vehicle Safety Standard # 111. We would appreciate your written response confirming that FMVSS # 111 states, that a "passenger vehicle weighing under 10,000 lbs. and having a left side and an interior mirror (field of view) that comply with the specifications in the standard may use any mirror of the (OEM) manufacturers or owners choice or, use no mirror at all on the right side of their vehicle. As this matter is of extreme urgency to us, ,we look forward to hearing from you soon. Again, we thank you for your unyielding thoughtfulness of public safety. |
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ID: nht93-4.16OpenDATE: June 3, 1993 FROM: John Womack -- Acting Chief Counsel, U.S. Department of Transportation, NHTSA TO: Berkley C. Sweet -- Executive Vice President, School Bus Manufacturers Institute TITLE: None ATTACHMT: Attached to letter dated 3-2-93 from Berkley C. Sweet to Mary Versailles (OCC 8393); Also attached to letter dated 3-20-90 from Stephen P. Wood to Cadwallader Jones (A35; VSA 102(14); Part 571.3) TEXT: This responds to your letter requesting definitions of primary, preprimary, and secondary school students. You write in response to our July 28, 1992 letter to you in which we state that the National Traffic and Motor Vehicle Safety Act, 15 U.S.C. S1581, et seq. (Safety Act), defines a school bus as a vehicle that is "likely to be significantly used for the purposes of transporting PRIMARY, PREPRIMARY, or SECONDARY school students to or from such schools or events related to such schools" (emphasis added). The terms primary, preprimary, and secondary school are not defined in the Safety Act or in the legislative history of the Act. However, NHTSA has historically interpreted "preprimary school" to refer to kindergarten, nursery schools and Head Start facilities. "Primary school" refers to elementary school, and "secondary school" refers to high school. I have enclosed a copy of our March 20, 1990 letter to Mr. Cadwallader Jones that discusses whether various institutions (e.g., church schools and colleges) are considered "schools" under the Safety Act. The various states may have their own definitions of a "school" for determining the use requirements for school vehicles. Therefore, you should check with the state where questions of school vehicle use are at issue. I hope the above information will be of assistance to you. If you have any further questions regarding this matter, please feel free to contact Walter Myers of my staff at this address or at (202) 366-2992. |
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ID: nht89-3.39OpenTYPE: INTERPRETATION-NHTSA DATE: NOVEMBER 19, 1989 FROM: GEORGE B. MADAY -- PRES., NETWORK USA INC. TO: ADMINISTRATOR -- NHTSA TITLE: DAYTIME RUNNING LIGHTS ATTACHMT: ATTACHED TO LETTER DATED 4-8-90 TO GEORGE B. MADAY FROM STEPHEN P. WOOD; (A35; STD. 108); GRAPHICS OMITTED. TEXT: We are assessing the U.S. market potential for an Automatic Light Switching Device for automobiles. The device works on the basis of a light sensor which automatically activates the vehicles headlights at a certain level of darkness (adjustable with pot entiometer). There is a manual override for the operator. This quality product is manufactured in Switzerland and is being used by the Swiss Police vehicles. As their U.S. agent, I seek to find out the following: 1. What legislation is in force or pending regarding the mandatory utilization of such daytime running lights for vehicles? 2. What regulations, standards, form s, etc., have to be submitted to you or the appropriate agency to ensure that the product meets any U.S. specifications or standards prior to importation. I look forward to a response at your earliest convenience. |
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ID: nht93-9.28OpenDATE: December 30, 1993 FROM: John Womack -- Acting Chief Counsel, NHTSA; Signature by Kenneth N. Weinstein TO: Dennis Platt -- Supervisor, Vehicle Safety & Equipment Section, State of Utah, Department of Public Safety, Utah Highway Patrol TITLE: None ATTACHMT: Attached to letter dated 12/7/93 from Dennis Platt to Office of the Chief Counsel (OCC-9439), NHTSA, letter dated 3/4/93 from John Womack to Robert A. Ernst, and letter dated 1/19/90 from Stephen P. Wood to Linda L. Conrad TEXT: This responds to your letter of December 7, 1993, requesting confirmation of a statement made by a NHTSA officer that there is no federal regulation that requires replacement of a deployed air bag. I am enclosing two letters that explain legal obligations to replace air bags which have been deployed. The first letter, dated January, 19, 1990, is to Ms. Linda L. Conrad. The second letter, dated March 4, 1993, is to Mr. Robert A. Ernst. As explained in those letters, Federal law does not require replacement of a deployed air bag in a used vehicle. In addition, there is no Federal law that prohibits selling a used vehicle with a supplemental restraint that is inoperable because of a previous deployment. However, our agency strongly encourages dealers and repair businesses to replace deployed air bags whenever vehicles are repaired or resold, to ensure that the vehicles will continue to provide maximum crash protection for occupants. Moreover, a dealer or repair business may be required by state law to replace a deployed air bag, or be liable for failure to do so. I am also enclosing a copy of the information sheet referred to in the two letters discussed above. 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. |
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ID: nht88-3.34OpenTYPE: INTERPRETATION-NHTSA DATE: 09/07/88 FROM: LEONARD M. PERKINS -- L AND M COMPANY TO: ROBERT BURNLEY -- SECRETARY OF TRANSPORTATION DEPARTMENT OF TRANSPORTATION TITLE: NONE ATTACHMT: ATTACHED TO LETTER DATED 02/06/89 EST, FROM ERIKA Z. JONES -- NHTSA TO LEONARD M. PERKINS, REDBOOK A33, STANDARD 108 TEXT: Dear Sir: We have an automobile safety device worthy of your consideration. According to a recent survey we read, the rear window brakelight has reduced rear end collisions by about 25% nationwide. We have travelled bumper to bumper freeway traffic for many years and found directional signals on most new cars very difficult to see, due to our line of vision being concentrated on the cars in front, on each side and the closeness of all cars at speeds of 50-60 miles per hour. Also, the placement of these signals now are where the car design people think they blend in best, m ainly in the bumper area. Our design patent has moved these signals up where they can be seen readily as the rear window brake light (see enclosed copies of patent application). Our suggestion for color of these directional side lights would be yellow, an eye catching color f or split second sightings. We feel that the turn signals joined with the rear window brake light should have a dramatic effect on rear and side collisions. Having spent much time driving Los Angeles and Phoenix freeways, we feel this would not only cut down accidents, but save millions of dollars in property damage each year. We have been told by informed sources that this conception is at present illegal. Your comments and help would be greatly appreciated. Yours truly, (FIGURES 1 - 5 OMITTED)
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ID: 77-1.5OpenTYPE: INTERPRETATION-NHTSA DATE: 01/18/77 FROM: AUTHOR UNAVAILABLE; F. Berndt; NHTSA TO: Marchal America TITLE: FMVSS INTERPRETATION TEXT: This is in reply to your letter of December 17, 1976, asking whether 15 U.S.C. 1392(d) permits the installation of quartz halogen headlamps on State-owned vehicles. It is understood that these headlamps are manufactured in France, and are not of sealed beam construction. Thus they do not conform to Motor Vehicle Safety Standard No. 108. Your letter also commented that certain "state highway and law enforcement agencies . . . have indicated . . . that they prefer the quartz halogen units but are reluctant to install these units in their state vehicles because they are not of an approved type." Importation and sale of nonconforming motor vehicle equipment is expressly forbidden by Section 108(a)(1)(A) of the National Traffic and Motor Vehicle Safety Act. A civil penalty of up to $ 1,000 may be imposed for each violation. Therefore, quartz halogen headlamps that do not conform to Standard No. 108 may not be imported into the United States and sold to State agencies. Your inquiry appears premised that such may be allowable pursuant to Section 1392(d) which reads in pertinent part: Nothing in the section shall be construed to prevent . . . the government of any State or political subdivision thereof from establishing a safety requirement applicable to motor vehicle or motor vehicle equipment procured for its own use if such requirement establishes a higher standard of performance than that required to comply with the otherwise applicable federal standard. Section 1392(d) reflects a primary purpose of the National Traffic and Motor Vehicle Safety Act that there be uniform national safety standards for the manufacture of motor vehicles, and that the flow of interstate commerce not be burdened by differing requirements among the States. An exception is made, however, that allows the States to set higher standards for vehicles manufactured for State use. Section 1392(d) would be inapplicable to your fact situation which, as we understand it, involves a conversion after purchase, and does not involve a procurement specification affecting the vehicle manufacturer. |
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ID: nht72-4.42OpenDATE: 08/21/72 FROM: AUTHOR UNAVAILABLE; Richard B. Dyson; NHTSA TO: Ryder Systems Incorporated TITLE: FMVSR INTERPRETATION TEXT: This is in reply to your letter of July 31, 1972, concerning work to be performed on new trucks. Your three questions are answered below. You ask, "What are the legal aspects of a road contractor doing the fifth-wheel work on a new truck?" The installation of a fifth wheel on a new vehicle would most likely make the installer a "final-stage manufacturer" under NHTSA Certification regulations (49 CFR Part 567) and regulations governing "Vehicles Manufactured in Two or More Stages" (49 CFR Part 568). Final-stage manufacturers bear the responsibility for certifying that the completed vehicle conforms to all applicable motor vehicle safety standards. The procedure for certifying is specified in the Certification regulations, copies of which are enclosed. Your second question is, "At what stage after purchase may a new truck be legally termed a used truck?" For our purposes, a used vehicle is any vehicle that has been purchased in good faith for a purpose other than resale (15 U.S.C. 1397(b)(1)). Your last question is, "Would the installation of extra lights or safety items be construed as final manufacturing?" The installation of readily attachable components, such as mirrors or tires, is not considered to be an activity which makes the installer a final-stage manufacturer. We are of the opinion that the same would be true regarding the installation of "extra" lights (those not required pursuant to Motor Vehicle Safety Standard No. 103, (49 CFR 571.108)). We cannot provide you with an opinion as to "safety items" as this term is too general. However, assuming that you are referring to items not required by a motor vehicle safety standard, our answer would most likely be the same. The manufacturer should determine whether the component he installs affects to a significant extent either the configuration or purpose of the vehicle. If it does not, (we will accept a manufacturer's reasonable determination in this regard) then the installer would not be considered a final-stage manufacturer. |
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ID: nht81-2.8OpenDATE: 03/24/81 FROM: AUTHOR UNAVAILABLE; F. Berndt; NHTSA TO: International Traders TITLE: FMVSS INTERPRETATION TEXT: This responds to your February 17, 1981, letter in which you requested information from this agency concerning "the grading standards applicable to truck tires." We have issued Uniform Tire Quality Grading Standards (49 Code of Federal Regulations @ 575.104) for passenger car tires which specify labeling information concerning the tire's treadwear, traction and heat resistance. However, these grading standards apply only to passenger car tires and, therefore, would not be applicable to the truck tires you purchase. There are, however, performance requirements applicable to truck tires, set forth in Federal Motor Vehicle Safety Standard No. 119 (49 Code of Federal Regulations @ 571.119), a copy of which is enclosed. The manufacturer of the truck tire must certify that the imported tire complies with the requirements of this standard by labeling the symbol "DOT" on the sidewall of the tire, according to the requirement of section S6.5(a) of the enclosed standard. This information may not be especially helpful to your company in comparing the price quotations, since every tire must have this certification to be legally imported into the United States. Should you need any further information concerning the requirements applicable to truck tires, please feel free to contact Mr. Stephen Kratzke of my staff at (202) 426-2992. Sincerely, ATTACH. INTERNATIONAL TRADERS February 17, 1981 National Highway Traffic Safety Administration -- Chief Counsel Dear Sir: We are in the process of gathering quotations for the import of truck tires for resale to heavy hauling trucking companies in the United States. We would appreciate receiving from you the grading standards for these tires. If you have any forms that are necessary for us to complete for you, please send these as well. Thank you. Very truly yours, Rusty D. Hitch |
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.