United States Department of TransportationNHTSA 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: aiam2418OpenMr. William G. Matthews, III, Division Manager, Universal Imports, 14622 Southlawn Lane, Rockville, Maryland 20850; Mr. William G. Matthews III Division Manager Universal Imports 14622 Southlawn Lane Rockville Maryland 20850; Dear Mr. Matthews: This is in response to your September 13, 1976, letter concerning ' line of racing/rally tires that are not Department of Transportation marked.'; I understand from your recent telephone conversation with Mar Schwimmer of my staff that the tires with which you are concerned are of the following size designations: 165/70 HR 10, 225/60 HR 14, 225/60 HR 13, and 195/70 HR 13.; Section S6 of Federal Motor Vehicle Safety Standard No. 109, *Ne Pneumatic Tires--Passenger Cars*, reads as follows:; >>>S6. *Nonconforming tires*. No tire of a type and size designatio specified in Table I of Appendix A that is designed for use on passenger cars and manufactured on or after October 1, 1972, but does not conform to *all the requirements of this standard*, shall be sold, offered for sale, introduced or delivered for introduction in interstate commerce, or imported into the United States, for any purpose. (emphasis added)<<<; because the size designations of the tires in question all appear i Table I of Appendix A, these tires are subject to the prohibitions of S6 unless they were manufactured before October 1, 1972. 'All the requirements of the standard' include both performance and labeling requirements.; Sincerely, Frank A. Berndt, Acting Chief Counsel |
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ID: aiam0425OpenMr. J. A. Westphal, Senior Staff Engineer, FWD Corporation, Clintonville, WI 54929; Mr. J. A. Westphal Senior Staff Engineer FWD Corporation Clintonville WI 54929; Dear Mr. Westphal: This is in reply to your letter of August 12 asking for a clarificatio of the effect of the recent firefighting vehicle amendment (36 F.R. 13926) on Federal standards published prior to September 1, 1971, but effective after that date.; Specifically you ask whether Standard No. 302, *Flammability o Interior Materials*, published on January 8, 1971, applies to firefighting vehicles on September 1, 1972, or September 1, 1974.; The firefighting vehicle amendment is effective September 1, 1971, an has no effect upon standards or amendments to standards issued before that date. Thus Standard No. 302 applies to firefighting vehicles as of September 1, 1972.; Sincerely, Lawrence R. Schneider, Acting Chief Counsel |
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ID: aiam5627OpenArthur N. Arschin, Esq. 450 Seventh Avenue, Suite 2803 New York, NY 10123; Arthur N. Arschin Esq. 450 Seventh Avenue Suite 2803 New York NY 10123; Dear Mr. Arschin: This responds to your letter to this agency askin whether the manufacturer identification numbers assigned to the Vee Rubber Company, Ltd. and the Vee Rubber International Company, Ltd. remain valid. The short answer is yes, if the plants remain in production. 49 CFR 574.5 requires each new or newly retreaded tire sold in the United States to have a tire identification number (TIN) labeled by the manufacturer on one sidewall of the tire. The TIN is intended to assist NHTSA to identify the production source of a tire in the event of a defect or noncompliance. The TIN must include a manufacturer identification mark (MIM) issued by NHTSA in accordance with 49 CFR 574.6. NHTSA issues a separate MIM for each plant that currently produces or retreads tires, and a plant can only have one MIM. Once NHTSA issues a MIM, the mark remains in effect as long as the plant to which it applies remains in production. In the event the plant ceases production, the mark assigned to that plant may not be further assigned or otherwise used by the manufacturer or anyone else. If the plant ceases production, NHTSA should be promptly notified so that the mark can be cancelled. With regard to your client rubber companies, the MIMs assigned to Vee Rubber Company, Ltd., YRU for Plant No. 1 and YRV for Plant No. 2, remain in effect if those plants are still in production. The MIMs assigned to Vee Rubber International Company, Ltd., 4A for Plant No. 1 and 5A for Plant No. 2 remain in effect if those plants are still in production. I hope this information is helpful to you. Should you have any questions or need additional information, feel free to contact Walter Myers of my staff at this address or at (202) 366-2992. Sincerely, John Womack Acting Chief Counsel; |
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ID: aiam4935OpenMr. John H. Heinrich District Director of Customs U.S. Customs Service 300 So. Ferry Street Terminal Island, CA 90731; Mr. John H. Heinrich District Director of Customs U.S. Customs Service 300 So. Ferry Street Terminal Island CA 90731; Re: Case No. 92-2704-00015 Dear Mr. Heinrich: This responds to you letter of December 5, 1991, enclosing a petition for relief from the forfeiture of '200 Spinner Wheel Nuts' seized by the Customs Service as violative of 49 CFR Sec. 571.211. The petitioner expresses the opinion that the wheel nuts should be exempt from DOT regulations, stressing safety considerations and the need to replace worn parts on vehicles manufactured in the l950's. You have also enclosed a copy of the petitioner's own parts list that identifies the wheel nuts as part of a conversion kit, intended to replace disc wheels with wire wheels. Federal Motor Vehicle Safety Standard No. 211, Wheel Nuts, Wheel Discs, and Hub Caps, 49 CFR 571.211, precludes, for use on passenger cars, wheel nuts that incorporate winged projections. The chrome wheel nuts depicted in the Moss Motors catalogue page which you enclosed (Parts Nos. 200-210 and 200-220) clearly incorporate winged projections, and are the type of wheel nuts that Standard No. 211 addresses and prohibits. As such, they may not be imported for sale in the United States. We have discounted petitioner's safety arguments. This is the first allegation in the nearly 24 years that the standard has been in effect that the spinners are required to replace original equipment, implying that there is no acceptable substitute that would conform with Standard No. 211. In our view, no justification has been shown for granting the petition. Sincerely, Paul Jackson Rice Chief Counsel; |
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ID: aiam2048OpenMr. Martin Rothfield, General Manager, Flasher Division, Ideal Corporation, 1000 Pennsylvania Avenue, Brooklyn, NY 11207; Mr. Martin Rothfield General Manager Flasher Division Ideal Corporation 1000 Pennsylvania Avenue Brooklyn NY 11207; Dear Mr. Rothfield: This is in reply to your letter of August 11, 1975. You ask fo confirmation that 'variable load flashers are permitted as replacement equipment by Federal Motor Vehicle Safety Standard No. 108 for any vehicle contemplated by Paragraph S2 of the Standard, where such devices shall operate in accordance with the appropriate Tables of the Standard.' You noted that some suppliers were under the impression that variable load flashers, which do not provide a failure indication, were not permitted as after-market replacements for fixed-load flashers.; The confusion apparently arose when the agency amended S4.5.6 o Standard No. 108 (June 6, 1974, 39 FR 20063) to permit variable-load flashers to be used (*i.e.*, to except from the failure indicator requirement) on trucks capable of accommodating slide-in campers (as well as vehicles of 80 inches or more overall width and those equipped to tow trailers, as provided by S4.5.6 before the amendment). To specify its intent more definitely, the amendment added the words, 'where a variable-load turn signal flasher is used,' to the exception to the requirement for a failure indicator. Some persons evidently thought that the new, explicit reference to variable-load flashers meant that such flashers could not be used as replacement equipment where the vehicles originally had fixed-load flashers.; That was not the agency's intent. The language was only added to mak it clear that where a fixed-load flasher is installed as original equipment, a failure indicator must be included. But a variable- load flasher may be used as replacement equipment for a fixed- load flasher on any of the vehicle classes specified in S2 as covered by the standard.; Incidentally, the statement in your letter that the June 1974 amendmen 'concerned itself only with original equipment applications' is incorrect. S2 of the standard states in pertinent part that it applies to 'lamps, reflective devices, and associated equipment for replacement of like equipment on vehicles to which this standard applies.' This means that equipment must comply with applicable requirements regardless of whether it is used as original or replacement equipment. For example, original and replacement variable load flashers must both meet the appropriate requirements of SAE Standard J590b, 'Automotive Turn Signal Flashers,' October 1965.; Sincerely, Frank A. Berndt, Acting Chief Counsel |
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ID: aiam0075OpenMr. George W. S. Smith, President, Ideal Manufacturing Company, 1107 South Seventh Street, Oskaloosa, IA 52577; Mr. George W. S. Smith President Ideal Manufacturing Company 1107 South Seventh Street Oskaloosa IA 52577; Dear Mr. Smith: In response to your trailer lighting questions during your visit wit Mr. W. R. Eason and the questions in your letter of March 26, 1968, the following information is provided.; >>>1. Your letter of March 26, 1968, indicates provision of two re tail lamps, two red or amber stop lamps, one white license plate lamp and two red or amber turn signal lamps for compliance with Motor Vehicle Safety Standard 108 after January 1, 1968. In addition to the afore specified lamps the Motor Vehicle Safety Standard 108 requires side reflex reflectors and side marker lamps as specified in the standard. Location of all lamps and reflectors shall be in accordance with Motor Vehicle Safety Standard 108 requirements. Additional requirements are specified for trailers that are 80 inches or more overall width.; 2. Your statement (March 26 letter) that, 'The above may be combine and may be Class A in photometric value but Class B in size,' is essentially correct except that turn signal lamps 'shall' be of Class A photometric value rather than 'may.'; 3. The provision of two Class A red reflectors and two Class A ambe reflectors does not completely conform to Motor Vehicle Safety Standard 108 requirements, because four Class A red reflectors and two Class A amber reflectors are required. Two of the red reflectors are for rear mounting and two are for aft side mounting, while the two amber reflectors are forward side mounting. Your interpretation that either reflective material conforming to specification L-S-300 or reflectors conforming to SAE Standard J594C may be utilized for the side reflex reflector requirements of Motor Vehicle Safety Standard 108 is correct; 4. With regard to the question of applicability of Motor Vehicle Safet Standard 108 to chassis trailers, enclosed is a copy of Federal Register Volume 33, Number 1, dated January 3, 1968. If the chassis trailer meets the requirements of this document, primarily that it is an incomplete vehicle and is properly labeled in accordance with paragraph 255.13, then the original manufacturer need not install all of the required lighting of Motor Vehicle Safety Standard 108.<<<; With respect to the requirements of Standard No. 108, I must point ou that this Bureau does not issue approvals on items of lighting equipment or on vehicle designs incorporating this equipment. Therefore, the above comments are for your information only and in no way relieve the vehicle manufacturer from his responsibility for certifying that the assembled vehicle meets the requirements of the standard.; The nomenclature as used on your proposed label drawing would b considered acceptable for certification requirements and we would appreciate your sending of an actual label sample when they are available,(sic) In addition, we would like to have for our records, the actual starting serial number that will identify your vehicles as being built on or after January 1, 1969.; Thank you for your interest in the safety program and we trust thi information will be of assistance to you in regard to your inquiries.; Sincerely, Joseph R. O'Gorman, Acting Director, Office of Performanc Analysis, Motor Vehicle Safety Performance Service; |
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ID: aiam5277OpenBarry H. Wells, M.D. 600 Ridgely Avenue, Suite 130 Annapolis, MD 21401; Barry H. Wells M.D. 600 Ridgely Avenue Suite 130 Annapolis MD 21401; Dear Dr. Wells: Thank you for your letter describing a device yo called an 'Emergency Brake Technology' (E.B.T.) system that you believe would eliminate jackknifing and improve the stopping distances of tractor trailers. A video tape accompanying your letter stated that the E.B.T. system operates by having a metal wedge slide below each wheel in response to an action by the driver. You requested the opportunity to testify or submit written comments about the benefits of this device. You also requested that the agency test the E.B.T. system. As Marvin Shaw of my staff explained to you, NHTSA issued a notice of proposed rulemaking (NPRM) on September 28, 1993, that addresses the lateral stability and control of medium and heavy vehicles. The agency is proposing to require these vehicles to be equipped with an antilock brake system (ABS) and to comply with a 30 mph braking-in-a-curve test on a low coefficient of friction surface. Mr. Shaw advised you that while the agency does not anticipate holding a public hearing on this rulemaking, you could submit written comments to the NPRM. In addition, we have submitted this correspondence, including your incoming letter and the video tape, to the public docket. We regret that we are unable to fulfill your request for NHTSA to test the E.B.T. system. Given our limited research budget, it is not possible for us to test every automotive safety-related piece of equipment that is introduced into the marketplace. I hope this information is helpful. If you have any further questions about NHTSA's activities, please feel free to contact Marvin Shaw at this address or by telephone at (202) 366-2992. Sincerely, John Womack Acting Chief Counsel; |
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ID: aiam1234OpenMs. Dianne Black, Engineering Liaison Assistant, British Leyland Motors, Inc., 600 Willow Tree Road, Leonia, NJ, 07605; Ms. Dianne Black Engineering Liaison Assistant British Leyland Motors Inc. 600 Willow Tree Road Leonia NJ 07605; Dear Ms. Black: This is in reply to your letter or July 18, 1973, regarding th applicability of Standard No. 302, 'Flammability of Interior Materials,' to a temporary sunvisor sleeve British Leyland plans for each of its 1974 model cars, to inform occupants about the seat belt interlock system.; The applicability of Standard No. 302 depends on whether th instruction sleeve is attached in such a way as to appear as a permanent part of the sunvisor or some other interior component covered by the standard. If the instruction sleeve is easily removable, is obviously not part of the sunvisor, and is clearly intended to be removed by the owner, we would not consider the sunvisor sleeve to be subject to the standard.; Yours truly, Richard B. Dyson, Assistant Chief Counsel |
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ID: aiam3209OpenMr. David Shomberg, Bus Con Corporation, 19 South Main Street, Spring Valley, New York 10977; Mr. David Shomberg Bus Con Corporation 19 South Main Street Spring Valley New York 10977; Dear Mr. Shomberg: This responds to your January 22, 1980, letter asking two questio about the use of your body conversion numbers on the certification labels of your vehicles you produce.; First, you ask whether a final-stage manufacturer may substitute it body conversion number for the vehicle identification number (VIN) that comes with the incomplete vehicle. The answer to this question is no. The VIN must be continued from the incomplete vehicle certification label to the final-stage certification label. However, you may insert your body conversion number on the label in addition to the VIN. Your number should appear at the bottom of the label below the required information.; In your second question, you ask whether you may include your bod conversion number on the alterers' label for previously certified vehicles that you alter. The answer to this question is yes. As indicated above the number should appear at the bottom of the label below the required information.; Sincerely, Frank Berndt, Chief Counsel |
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ID: aiam4036OpenEnere H. Levi, Esq., Assistant Attorney General, Office of the Attorney General, American Samoa Government, Pago Pago, American Samoa 96799; Enere H. Levi Esq. Assistant Attorney General Office of the Attorney General American Samoa Government Pago Pago American Samoa 96799; Dear Mr. Levi: Thank you for your letter of September 18, 1985, to Mr. Hal Paris o this agency requesting information on the bumper requirements that apply to small trucks. You also asked about the effect of our standards on vehicles sold in your Territory. Your letter was referred to my office for reply. I hope the following discussion answers your questions.; Under the authority of the National Traffic and Motor Vehicle Safet Act (15 U.S.C. 1381 *et seq*.) and the Motor Vehicle Information and Cost Savings Act (15 U.S.C. 1901 *et seq*.), we have issued Part 581, *Bumper Standard* (49 CFR Part 581), a copy of which is enclosed. The Part 581 standard applies only to passenger motor vehicles. Section (2)(1) of the Cost Savings Act (15 U.S.C. 1901(1)) defines a 'passenger motor vehicle' as a vehicle designed to carry 12 persons or less, except a motorcycle or a truck not designed primarily as a passenger carrier, but is instead designed primarily to carry cargo. Therefore, under Federal law, a small utility truck may be sold without any rear bumper.; Both the Vehicle Safety Act and the Cost Savings Act apply to moto vehicles manufactured in or imported into the United States. Both Acts define the term 'State' to include American Samoa (15 U.S.C. 1391(8) and 1901(16)). Therefore, the requirements of the Part 581 standard would apply to vehicles sold in American Samoa.; If you have any further questions, please let me know. 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.