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: nht91-1.40OpenDATE: February 14, 1991 FROM: Anne Lombardi -- Acting Director, Office of Passenger Enforcement and Facilitation, Department of the Treasury TO: Paul Jackson Rice -- Chief Counsel, NHTSA TITLE: None ATTACHMT: Attached to letter dated 3-11-91 from Paul Jackson Rice to Anne Lombardi (A37; VSA 102(3) Part 591) TEXT: We have Military Customs Advisors stationed around the world who provide information and guidance to Military Customs Inspectors performing preshipment examinations of automobiles and other vehicles. We would appreciate your opinion on a question which was raised by our Advisor stationed at Subic Bay in the Philippines. Military and DOD civilian employees stationed in that country frequently purchase automobiles which are composites of old chassis and engines, of U.S. manufacture, and new bodies and interiors, fabricated and attached to the chassis by local Filipino car shops. Normally, the chassis and engines were not taken abroad by the importers, but were purchased in the Philippines from other sources. In most cases the chassis are said to have been manufactured prior to January 1, 1969. The question is simple. Which DOT regulations apply to these automobiles, those applicable to the year the chassis was manufactured, or those applicable to the year the new body is attached? We are writing to you at the recommendation of the Office of Vehicle Safety Compliance. Additional information, if needed, is available from Sid Allshouse at (202) 566-5607. |
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ID: nht95-3.5OpenTYPE: INTERPRETATION-NHTSA DATE: June 8, 1995 FROM: John Womack -- Acting Chief Counsel, NHTSA TO: Ron Hooker -- Missouri Department of Agriculture TITLE: NONE ATTACHMT: ATTACHED TO 5/9/95 LETTER FROM RON HOOKER TO JOHN WOMACK (OCC 10906) TEXT: Dear Mr. Hooker: This responds to your question about whether the State of Missouri has authority to promulgate regulations relating to the safety of motor vehicles powered by alternative fuels, particularly compressed natural gas (CNG). The short answer is that while M issouri is generally preempted in this area, it could issue its own more stringent safety standard for State-owned vehicles. Federal law will preempt a State law if (1) there is a Federal safety standard in effect, (2) the State law covers the same aspect of performance as that Federal standard, and (3) the State law is not identical to the Federal standard. Specifically, sec tion 30103(b) of Title 49 of the United States Code states that (b) Preemption - (1) When a motor vehicle safety standard is in effect under this chapter, a State or political subdivision of a State may prescribe or continue in effect a standard applicable to the same aspect of performance of a motor vehicle or motor vehicle equipment only if the standard is identical to the standard prescribed under this chapter. However, the United States Government, a State, or a political subdivision of a State may prescribe a standard for a motor vehicle or motor vehicle equip ment obtained for its own use that imposes a higher performance requirement than that required by the otherwise applicable standard under this chapter. State safety standards applicable to CNG fuel system integrity are generally preempted by Federal law. The National Highway Traffic Safety Administration (NHTSA) has issued Federal motor vehicle safety standard (FMVSS) No. 303, Fuel system integrity of compressed natural gas vehicles. (59 FR 19659, April 25, 1994, copy enclosed). The Standard specifies frontal barrier and rear barrier crash tests conducted at 30 mph and a lateral moving barrier crash test conducted at 20 mph. The Standard applies to passenger cars, multipurpose passenger vehicles, trucks and buses that have a gross vehicle weight rating (GVWR) of 10,000 pounds or less and use CNG as a motor fuel. It also applies to school buses regardless of weight that use CNG as a motor fuel. Th e Standard takes effect September 1, 1995. Accordingly, after September 1, 1995, Missouri could only issue its own safety standard applicable to CNG vehicle fuel system integrity if the State safety standard is identical to FMVSS No. 303. The one excep tion to requiring such identical standards is that Missouri could prescribe a standard for motor vehicles obtained for its own use, provided the State law imposed a higher performance requirement than the level of performance prescribed by FMVSS No. 303. Thus, Missouri could issue its own more stringent safety standard for State-owned vehicles. NHTSA further notes that Missouri is free to issue safety standards applicable to the fuel system integrity of vehicles powered by other alternative fuels (e.g., liquid propane, hydrogen), since the agency has not issued any FMVSS applicable to other alt ernative fuels. I hope you find this information helpful. If you have any other questions, please contact Marvin Shaw at this address or by phone at (202) 366-2992. |
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ID: nht74-4.45OpenDATE: 01/18/74 FROM: AUTHOR UNAVAILABLE; Lawrence R. Schneider; NHTSA TO: Rogue Racing TITLE: FMVSR INTERPRETATION TEXT: Dr. Gregory asked me to respond to your January 3, 1974, letter asking whether the National Highway Traffic Safety Administration proposal to modify the definition of Multipurpose Passenger Vehicle would affect importation of The Thing. The proposed modification would reclassify vehicles like The Thing as passenger vehicles, but it would not prohibit their importation. Volkswagen would have to incorporate several additional safety features in The Thing to meet the higher standards for passenger cars. We have not made a final decision on the proposed redefinition. Volkswagen as the manufacturer of The Thing might be able to give you a better evaluation of The Thing's future than we have at present. Sincerely, January 3, 1974 Dr. James B. Gregory National Highway Traffic Safety Administration A recent article in the January issue of Four Wheeler magazine states that NHTSA plans to modify the definition of multi-purpose vehicles to exclude the Volkswagen 181 (The Thing). As a manufacturer and wholesaler of accessories for the Thing, we are very concerned how the change in definition will effect the importation of the Thing and/or the safety specification which must be met before the Thing may be sold in this country. We would appreciate any information which is now available, and any future information concerning specification required for the Thing. Thank you. Joshua E. Bruner |
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ID: 10036Open George W. Sudenga, Esq. Dear Mr. Sudenga: This responds to your letter following up on my May 18, 1994, letter to your client, Mr. Neil Rowe, about Mr. Rowe's product, the "Glad Grip." In my letter, I provided information about the National Highway Traffic Safety Administration's (NHTSA's) requirements for manufacturers of motor vehicle equipment, and explained that NHTSA has not issued a Federal motor vehicle safety standard (FMVSS) applicable to a product such as the Glad Grip. In your followup letter, you indicated we did not answer your request for "approval of NHTSA in advance of major marketing efforts," concerning your client's product. I regret that my earlier letter was unclear on the issue of NHTSA "approval" of motor vehicles or motor vehicle equipment. NHTSA does not approve motor vehicles or items of motor vehicle equipment, nor does the agency endorse any commercial products. Instead, the National Traffic and Motor Vehicle Safety Act establishes a "self-certification" process under which each manufacturer is responsible for certifying that its products meet all applicable safety standards. As I stated in the earlier letter, the agency has not issued any safety standards for the Glad Grip. Even if there were an applicable FMVSS, NHTSA would not "approve" the Glad Grip; rather, Mr. Rowe would self- certify his product. I hope you find this information helpful. If you have any other questions, please contact Marvin Shaw of my staff at this address or by phone at (202) 366-2992. Sincerely,
John Womack Acting Chief Counsel ref:106 d:7/1/94
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1994 |
ID: nht94-3.54OpenTYPE: INTERPRETATION-NHTSA DATE: July 1, 1994 FROM: John Womack -- Acting Chief Counsel, NHTSA TO: George W. Sudenga -- Esq., Johnson, Sudenga, Latham & Peglow TITLE: NONE ATTACHMT: Attached to letter dated 5/25/94 from George W. Sudenga to Marvin Shaw and letter dated 5/18/94 from John Womack to Neil Rowe. TEXT: This responds to your letter following up on my May 18, 1994, letter to your client, Mr. Neil Rowe, about Mr. Rowe's product, the "Glad Grip." In my letter, I provided information about the National Highway Traffic Safety Administration's (NHTSA's) requi rements for manufacturers of motor vehicle equipment, and explained that NHTSA has not issued a Federal motor vehicle safety standard (FMVSS) applicable to a product such as the Glad Grip. In your followup letter, you indicated we did not answer your re quest for "approval of NHTSA in advance of major marketing efforts," concerning your client's product. I regret that my earlier letter was unclear on the issue of NHTSA "approval" of motor vehicles or motor vehicle equipment. NHTSA does not approve motor vehicles or items of motor vehicle equipment, nor does the agency endorse any commercial products. I nstead, the National Traffic and Motor Vehicle Safety Act establishes a "self-certification" process under which each manufacturer is responsible for certifying that its products meet all applicable safety standards. As I stated in the earlier letter, t he agency has not issued any safety standards for the Glad Grip. Even if there were an applicable FMVSS, NHTSA would not "approve" the Glad Grip; rather, Mr. Rowe would self-certify his product. I hope you find this information helpful. If you have any other questions, please contact Marvin Shaw of my staff at this address or by phone at (202) 366-2992. |
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ID: nht71-5.37OpenDATE: 09/30/71 FROM: AUTHOR UNAVAILABLE; Robert L. Carter; NHTSA TO: Mercedes Benz of North America TITLE: FMVSS INTERPRETATION TEXT: This is in reply to your letter of August 20, 1971, in which you asked whether the shoulder belt anchorages installed by Mercedes in its heavy trucks (over 10,000 CVWR) must meet the strength requirements of Standard No. 210, even though the standard does not require shoulder belt anchorages in vehicles over 10,000 pounds GVWR. It is our opinion that because these anchorages are not required to be installed, they are not required to meet the strength requirements of Standard No. 210. You may therefore continue to use plastic covers on the anchorages and need not redder them unusable. Please advise us if you have further questions. |
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ID: nht74-3.47OpenDATE: 05/24/74 FROM: AUTHOR UNAVAILABLE; Frank Berndt; NHTSA TO: J. Alec Reinhardt TITLE: FMVSR INTERPRETATION TEXT: This is in reply to your letter of May 17, 1974, asking us to approve language to be substituted for the first two sentences of the second paragraph of White's version of the defect notification letter in campaign #73-0140, as well as substitute language suggested by the Court. We would consider the language of either submission to conform to 49 CFR Part 577 if the word "may" is stricken. The sentence would then read, "We have found that a defect exists in that. . . ." We have interpreted the regulations to require the finding that the defect exists, not that it may exist. However, the notification letter may indicate that the defect may not be present in every vehicle if that is the case. |
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ID: nht73-5.41OpenDATE: 11/02/73 FROM: AUTHOR UNAVAILABLE; Robert L. Carter; NHTSA TO: Green Bus Lines, Inc. TITLE: FMVSS INTERPRETATION TEXT: This is in response to your letters of July 30 and August 21, 1973, concerning the requirements of Federal Motor Vehicle Safety Standard No. 205, Glazing Materials, for materials used in windshields. (Illegible Word) understand and share your concern over the damage and the hazards caused by vandalism toward buses. Standard No. 205 currently prohibits the use of plastics in windshields simply because today's commercial plastics, including the one for which you enclosed a brochure, cannot meet the abrasion resistance test specified in the standard. As long as windshield wipers are used, we are of the opinion that this requirement is essential. We hope that glazing manufacturers will develop materials that will protect against the problems you have described, while at the same time meeting the necessary performance requirements. When such materials are developed, we, of course, would amend the standard as necessary to permit their use. |
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ID: nht93-6.8OpenDATE: August 12, 1993 FROM: Joe de Sousa -- President, Safety Pro's International, Inc. TO: Office of Chief Counsel -- NHTSA TITLE: None ATTACHMT: Attached to letter dated 3/10/94 from John Womack to Joe de Sousa (A42; Std. 108) and letter dated 8/12/93 from Joe de Sousa to Richard Van Iderstine TEXT: We are a company marketing automotive lighting products operating nationwide. In order to provide quality service to our customers, it is very important for us to assure proper application of these products according to state and federal laws. It is suggested by Mr. Richard Van Iderstine of your administration to request in writing an interpretation of Ruling #108 as amended earlier this year. We would appreciate your assistance in this regard so that we might represent our products properly and make any changes as deemed necessary. We thank you in advance for your consideration. |
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ID: nht71-2.6OpenDATE: 02/12/71 FROM: AUTHOR UNAVAILABLE; R. H. Compton; NHTSA TO: Koito Manufacturing Co., Ltd. TITLE: FMVSS INTERPRETATION TEXT: This is in reply to your letter of January 22, 1971, to Mr. Charles A. Baker of this Office concerning questions on paragraph S4.1.1.7 of Federal Motor Vehicle Safety Standard No. 108. "Red" was inadvertently included in paragraph S4.1.1.7 of the amendment to Standard No. 108 published on October 31, 1970. It is anticipated that this paragraph will be further amended in the near future by changing" . . . requirements for Class A red turn signal lamps . . ." to ". . . requirements for Class A turn signal lamps. . ." The answers to your questions are therefore as follows: 1. Amber turn signal lamps shall conform to the minimum candlepower requirements for Class A amber as specified in Table 2 of SAE J575d. 2. There is no maximum candlepower requirement for amber front turn signal lamps. |
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.