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: aiam2329OpenMr. David E. Martin, Director, Automotive Safety Engineering, General Motors Corporation, General Motors Technical Center, Warren, Michigan 48090; Mr. David E. Martin Director Automotive Safety Engineering General Motors Corporation General Motors Technical Center Warren Michigan 48090; Dear Mr. Martin: This responds to General Motors Corporation's May 27, 1976, petition t commence rulemaking to amend Standard No. 105-75, *Hydraulic Brake Systems*, in order to return one sentence to the text of S5.1.5.2(a) that was omitted in a September 17, 1975, revision of that section (40 FR 42872). The sentence reads:'However, the maximum control force for the fifth stop in the case of a vehicle manufactured before September 1, 1976, shall be not more than plus 60 pounds of the average control force for the baseline check (but in no case more than 110 pounds).'; The National Highway Traffic Safety Administration considers a petitio to amend the standard to be unnecessary because the omission was inadvertent and did not constitute a substantive change to the requirements of the standard. Therefore, an interpretative amendment to conform the language to that intended will be forthcoming in the near future. Interested persons are notified that the interim control force value has been in effect for all vehicles of 10, 000 pounds gross vehicle weight rating or less despite the omission of the sentence on September 17, 1975.; Thank you for bringing this omission to the attention of the agency. Yours truly, Frank Berndt, Acting Chief Counsel |
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ID: aiam0314OpenMr. P.H.G. Morgan, Managing Director, Morgan Motor Company, Ltd., Pickersleigh Road, Malvern Link, Worchestershire, England; Mr. P.H.G. Morgan Managing Director Morgan Motor Company Ltd. Pickersleigh Road Malvern Link Worchestershire England; Dear Mr. Morgan: This is in reply to your letter of March 17, 1971, in which yo requested further clarification of the test procedures of the standard on side door strength, Standard No. 214. Your diagram of the Morgan Plus 8 shows a horizontal line drawn across the door 5 inches above the lowest point of the door. This would appear to be an accurate depiction of the location of the lower edge of the loading device as specified in the standard. You express concern that the line is a considerable distance from the ground, but under the requirements of the standard, the height above the lower edge of the door is the relevant height, and not the height above ground.; I hope this will help to resolve your questions with respect t Standard No. 214.; Sincerely, Lawrence R. Schneider, Acting Chief Counsel |
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ID: aiam5116OpenMr. David H. B. Lee President, Lee Family, Inc. 701 East 30th Hutchinson, KS 67502; Mr. David H. B. Lee President Lee Family Inc. 701 East 30th Hutchinson KS 67502; "Dear Mr. Lee: This responds to your letter of December 29, 1992, wit respect to a 'Third Brake Light Conditions Sensor', for which you have requested a review and testing. You have also asked for our comments and advice on the sale and promotion of this product. We assume that you would like to sell it in the aftermarket to vehicle owners. We have reviewed the videotape you enclosed, and are able to advise you on this basis. The tape shows that the device is intended for installation by the owner of the vehicle, and, when installed, causes the center highmounted brake lamp to flash in proportion to braking effort (i.e., a panic or quick stop produces a higher flash rate than a stop made at a slower vehicle deceleration). Motor vehicle lighting in the United States is subject to both Federal and State requirements. The National Traffic and Motor Vehicle Safety Act and Federal Motor Vehicle Safety Standard No. 108 Lamps, Reflective Devices, and Associated Equipment are the Federal requirements to which I refer. Standard No. 108 prescribes requirements for center highmounted stop lamps that must be followed by the manufacturer of the vehicle, and met at the time the vehicle is sold by the dealer to its first owner. One of these requirements is that the center highmounted stop lamp be steady burning when it is in use. Because the Sensor creates a flashing light, a vehicle manufacturer would not be able to use it as original equipment on a vehicle subject to Standard No. 108's requirements for center lamps. These vehicles are passenger cars manufactured on and after September 1, 1985, and light trucks and vans manufactured on and after September 1, 1993. The Safety Act governs modifications to vehicles after their initial sale. This Act does not prohibit a vehicle owner from modifications that affect compliance with Standard No. 108 (or any other Federal motor vehicle safety standard). Thus, a vehicle owner may install the Sensor without violation of Federal requirements. However, we interpret the Safety Act as prohibiting the installation of the Sensor by a manufacturer, dealer, distributor, or motor vehicle repair business. Under the Act, these persons shall not 'render inoperative, in whole or in part, any device or element of design installed in accordance with a Federal motor vehicle safety standard.' In our view, this forbids the installation of equipment that would take a vehicle out of compliance with a Federal motor vehicle safety standard. However, the Act does not forbid the sale of componentry such as the Sensor which creates a noncompliance once it is installed. In summary, under Federal law, any person may sell your device, but only a person other than a manufacturer, dealer, distributor, or motor vehicle repair business may install it. We are unable to advise you as to whether the laws of any State prohibit the use of a flashing center highmounted stop lamp, and recommend that you consult the American Association of Motor Vehicle Administrators for an opinion. Its address is 4600 Wilson Boulevard, Arlington, Va. 22203. We are returning your videotape and sample Sensors. Sincerely, Paul Jackson Rice Chief Counsel Enclosures"; |
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ID: aiam5403OpenMr. Dietmar K. Haenchen Manager, Vehicle Regulations Volkswagen of America, Inc. 3800 Hamlin Road Auburn Hills, MI 48326; Mr. Dietmar K. Haenchen Manager Vehicle Regulations Volkswagen of America Inc. 3800 Hamlin Road Auburn Hills MI 48326; "Dear Mr. Haenchen: This responds to your request for an interpretatio of marking requirements in 49 CFR part 541 Federal Motor Vehicle Theft Prevention Standard for high theft vehicle lines' replacement parts. The answer to both of your questions is VW is still required to mark the replacement parts in question. In your letter, you explained that the Volkswagen Corrado line, a high theft line, was parts marked (pursuant to 49 CFR part 541) in model years 1990 through 1994. For model year 1995, NHTSA granted an exemption from parts marking for the Corrado line, based on the inclusion of an approved antitheft device as standard equipment on all models in the Corrado line. (58 FR 28434, May 13, 1993). However, you informed us in your letter that the Corrado will not be sold in the United States for MY 1995. Your first question asks whether replacement parts for the Corrado line are exempted from the parts marking requirements of part 541. The answer is no. Section 543.7(d) specifies that part 543 exemptions apply only to lines that are the subject of the grant, and are equipped with the antitheft device on which the line's exemption was based. You inform us that the Corrado will not be offered for sale in the U.S. in MY 1995. If the Corrado will not be offered for sale in this country, then no Corrrados sold in the U.S. will be equipped with the approved antitheft device. If no Corrado is so equipped, the part 543 exemption would not apply to the Corrado line. Thus, Volkswagen would be required to continue to mark any Corrado replacement parts, subject to part 541, offered for sale in the U.S. In your letter, you cited an October 12, 1989 NHTSA interpretation letter to Saab-Scania of America to support your position that the Corrado's replacement parts need not continue to be marked. We do not believe that the letter to Saab supports your position. Saab received an exemption from parts marking for the Saab 9000 for the 1989 model year, and asked NHTSA to clarify the scope of the part 543 exemption. On page two of the letter to Saab, NHTSA stated that Saab was free to discontinue marking of original equipment and replacement parts for the Saab 9000 as soon as the part 543 exemption took effect, 'provided that Saab actually installed the antitheft device described in its petition...' The letter to Saab establishes that if it does not install the antitheft device on the exempted line, a manufacturer is not free to discontinue marking replacement parts on the line. Your second question was whether replacement parts marking may be terminated at some point after a high theft line subject to parts marking, is no longer produced. The answer is no. This issue was addressed in the final rule establishing 49 CFR part 541 (50 FR 43166, October 25, 1985): Once a line is selected as a high theft line, each covered major replacement part designed for use on that line must be identified as a replacement part. That requirement remains in effect as long as those replacement parts are produced. (50 FR 43178). Thus, as long as replacement parts are produced for a high theft line subject to parts marking, the replacement parts must continue to be marked. I hope that this information is helpful. If you have any further questions, please contact Dorothy Nakama of my staff at (202) 366-2992. Sincerely, John Womack Acting Chief Counsel"; |
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ID: aiam1913OpenMr. Danny J. Lanzdorf, Supervising Engineer, Oshkosh Truck Corporation, P.O. Box 560, Oshkosh, WI 54901; Mr. Danny J. Lanzdorf Supervising Engineer Oshkosh Truck Corporation P.O. Box 560 Oshkosh WI 54901; Dear Mr. Lanzdorf: This responds to your April 1, 1975, request for confirmation that th emergency braking stopping distance requirements in S5.7.2.3 of Standard No. 121, *Air brake systems*, specify that, when stopped six times for each configuration of weight and speed specified in S5.3.1.1 on a road surface with a skid number of 75 (with a single failure introduced in the service brake system), the vehicle must stop at least once within the distances specified in Column 3 of Table II and no part of the vehicle must leave the 12-foot roadway. You also request confirmation that modulation of the service brake control during the stop is not prohibited.; With certain exceptions, the statements in your letter are correct Your interpretation only sets out the basic stopping distance requirements for those vehicles which the manufacturer has chosen to make conform to S5.7.2 of the standard. Thus, your interpretation does not include any of the requirements of the emergency braking capability option found in S5.7.1. Additionally, your interpretation does not include the requirements for a truck-tractor at unloaded vehicle weight plus 500 pounds, or for the trucks and buses which qualify for the interim requirements of S5.7.2.3.1 and S5.7.2.3.2.; Section S5.7.2 does not prohibit modulation of the emergency brakin capability, and modulation by means of the service brake control is therefore permissible.; Yours truly, Richard B. Dyson, Assistant Chief Counsel |
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ID: aiam1460OpenMr. Charles E. Park, President, Intermodal Services, Inc., P.O. Box 111, 4 Lavista - Perimeter Park - Suite 130, Tucker, GA 30084; Mr. Charles E. Park President Intermodal Services Inc. P.O. Box 111 4 Lavista - Perimeter Park - Suite 130 Tucker GA 30084; Dear Mr. Park: This responds to your April 8, 1974, request for a waiver from Standar 121, *Air brake systems*, to permit the manufacturer of semi-trailers which do not comply with the standard after its effective date.; Our authority to enforce standards under S108(a)(1) of the Nationa Traffic and Motor Vehicle Safety Act of 1966 prohibits the sale of a vehicle which does not comply with applicable standards. We are unable to permit by regulation what is prohibited by this section of the law.; We do have under consideration petitions to delay the effective date o Standard 121 as it applies to trailers.; Yours truly, Richard B. Dyson, Assistant Chief Counsel |
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ID: aiam3148OpenMr. William Shapiro, Volvo of America, Rockleigh, NJ 07647; Mr. William Shapiro Volvo of America Rockleigh NJ 07647; Dear Mr. Shapiro: This is in response to the questions that you addressed to Mr. Hug Oates over the telephone with regard to auxiliary fuel tanks. I have enclosed a copy of a letter which was sent to a company that planned to manufacture auxiliary fuel tanks for passenger cars and to do some installation. The principles enunciated in that letter are applicable to auxiliary fuel tanks intended for use in all types of motor vehicles except motor carriers in interstate commerce. If you have any further questions after reading the enclosed letter please feel free to contact Ms. Debra Weiner of my office who is familiar with the issues arising from the manufacture and use of auxiliary fuel tanks.; Sincerely, Frank Berndt, Chief Counsel |
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ID: aiam1175OpenMr. Edward W. Gaylord, Vice President, Gaylord Products, Inc., 1918 Prairie Avenue, Chicago, IL 60616; Mr. Edward W. Gaylord Vice President Gaylord Products Inc. 1918 Prairie Avenue Chicago IL 60616; Dear Mr. Gaylord: This is in reply to your letter of June 26, 1973, to Mr. Vinson of thi office, enclosing the proposed Panther certification label, and asking whether it conforms to our requirements. The label is arranged as a narrow horizontal strip with two lines of type.; The label contains the required statements in the required order, an thus fulfills the requirements.; Sincerely, Richard B. Dyson, Assistant Chief Counsel |
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ID: aiam4377OpenMr. John Scott Hatt, 1215 N. Quinn Street, Apt #2, Arlington, VA 22209; Mr. John Scott Hatt 1215 N. Quinn Street Apt #2 Arlington VA 22209; Dear Mr. Hatt: This is in reply to your letter of June 8, 1987, to this agency askin about the legality of having 'a lighted sign on the side of a car door used for advertising purposes.' You have also asked whether such a sign would be a safety hazard to other drivers.; There is no Federal prohibition against installation of such a sign Its legality would be determined under local laws where a vehicle with a lighted sign would be registered and operated. You might wish to seek the advice of Arlington traffic officials and the Virginia State Police on this subject. It is not possible to say whether such a sign would be a safety hazard. Unlit advertising signs seem permissible in some areas on the sides of buses.; Sincerely, Erika Z. Jones, Chief Counsel |
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ID: aiam3518OpenMr. David Traxler, 147 King George Way, Columbia, SC 29210; Mr. David Traxler 147 King George Way Columbia SC 29210; Dear Mr. Traxler: This is to follow-up your telephone call of October 29, 1981, askin whether any Federal motor vehicle safety standards apply to 'hatchback' door latches.; Safety Standard No. 206, *Door Locks and Door Retention Components* includes requirements for side door latches. We have enclosed a copy of that standard for your convenience.; There are no Federal motor vehicle safety standards applicable to th rear latch of a hatchback. However, even in the absence of a safety standard, the defect provisions of the National Traffic and Motor Vehicle Safety Act may be applicable. Sections 151 *et seq*. of the Act provide that manufacturers of motor vehicles and motor vehicle equipment must notify owners of vehicles and equipment with safety-related defects and remedy those defects free of charge.; Sincerely, Frank Berndt, 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.