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: aiam5366OpenMr. Fred Benford 100+ Motoring Accessories 2220 East Orangewood Avenue Anaheim, CA 92806-61100; Mr. Fred Benford 100+ Motoring Accessories 2220 East Orangewood Avenue Anaheim CA 92806-61100; "Dear Mr. Benford: This responds to your request for an interpretatio of Federal Motor Vehicle Safety Standard (FMVSS) No. 211, Wheel nuts, wheel discs and hub caps. You wrote that your company manufactures aluminum wheel covers without 'protruding objects.' You requested confirmation that the wheel covers do not violate any FMVSS. Our response is provided below. By way of background information, the National Highway Traffic Safety Administration (NHTSA) does not provide approvals of motor vehicles, or of motor vehicle equipment. Under the National Traffic and Motor Vehicle Safety Act (Safety Act), it is the responsibility of the manufacturers of motor vehicle equipment to ensure that its equipment meet applicable requirements. The following represents our opinion based on the facts provided in your letter. Standard No. 211 regulates wheel nuts, wheel discs, and hub caps. Since 'wheel discs' encompasses wheel covers, your company's wheel covers are subject to Standard No. 211. S4. Requirements of Standard No. 211 states in part: As installed on any physically compatible combination of axle and wheel rim, wheel nuts, wheel discs, and hub caps for use on passenger cars and multipurpose passenger vehicles shall not incorporate winged projections ... In your letter, you stated that your wheel covers do not have any 'protruding objects.' Since Standard No. 211 prohibits wheel discs (covers) with 'winged projections,' if your company's wheel covers do not incorporate 'winged projections,' the wheel covers would satisfy Standard No. 211. 'Winged projection' is defined at S3.2 of Standard No. 211 as an exposed cantilevered appendage that projects radially from a wheel disc and that typically has front, edge, and/or rear surfaces which are not in contact with the wheel when the wheel disc is installed on the axle. You also asked whether wheel covers made of aluminum violate any FMVSS. The answer is no, because Standard No. 211 does not specify materials for use in wheel covers. However, since wheel covers are 'motor vehicle equipment,' your company must ensure that the wheel covers are free of safety-related defects under the Safety Act. Sections 151-159 of the Safety Act concern the recall and remedy of products with defects related to motor vehicle safety. In the event that your company or NHTSA determines that the wheel covers have a safety-related defect, your company would be responsible for notifying purchasers of the defective wheel covers and remedying the problem free of charge. I hope 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: aiam1851OpenMr. Danny Lanzdorf, Oshkosh Truck Corporation, 2307 Oregon Street, Oshkosh, WI 54901; Mr. Danny Lanzdorf Oshkosh Truck Corporation 2307 Oregon Street Oshkosh WI 54901; Dear Mr. Lanzdorf: This responds to the questions you raised in a March 18, 1975 telephone conversation with Mark Schwimmer of this office, concerning the effective date of Federal Motor Vehicle Safety Standard No. 106-74, *Brake Hoses,* as applied to the brake hose assemblies in fire trucks which you manufacture.; Standard No. 106-74 became effective for brake hose assemblies on Marc 1, 1975. An assembly which is not completed until it is installed in a vehice (sic) is considered to have been manufactured on the date of installation. If that installation occurred on or after March 1, then the assembly must comply with the standard. While 49 CFR Part 571.8 provides in certain cases for delay of the effective date of a standard with respect to firefighting vehicles, such a delay is available only for a vehicle requirement. There is no change in the March 1, 1975, effective date for brake hose assemblies.; Sincerely, James C. Schultz, Chief Counsel |
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ID: aiam0394OpenMr. 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 July 1, 1971, concerning the Tir Identification and Record Keeping Regulation (49 CFR 574).; You are correct in your interpretation of the regulation, the vehicl manufacturer is not required to forward tire data to the tire manufacturer. The vehicle manufacturer's responsibilities are limited to maintaining a record of the tires on or in the vehicle when shipped along with a record of the names and addresses of first purchasers of the vehicles equipped with such tires. The method of complying with these requirements is left to the vehicle manufacturer. In the event of a defect notification, the tire manufacturer will be under an obligation to notify the vehicle manufacturer describing the suspect tires.; If we can be of further assistance, please feel free to write. Sincerely, Lawrence R. Schneider, Acting Chief Counsel |
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ID: aiam4294OpenMr. T. Chikada, Manager, Automotive Lighting, Engineering Control Dept., Stanley Electric Co., Ltd., 2-9-13, Nakemeguro, Meguro-ku, Tokyo 153, Japan; Mr. T. Chikada Manager Automotive Lighting Engineering Control Dept. Stanley Electric Co. Ltd. 2-9-13 Nakemeguro Meguro-ku Tokyo 153 Japan; Dear Mr. Chikada: This is in reply to your letter of March 13, 1987, with respect to th mounting height of driving lamps and front fog lamps. Noting that these Lamps are not equipment required by Federal Motor Vehicle Safety Standard No. 108, you have asked whether they need to be mounted within the range of height which the standard prescribes for headlamps, or may they be mounted, for example, at a height lower than 22 inches such as in the front bumper.; Any lamp that is not required by Standard No. 108 may be added to motor vehicle and located wherever it appears suitable, provided that the lamp at its location does not impair the effectiveness of lighting equipment required by the standard. Headlamps, parking lamps, and turn signal lamps are the lighting equipment required by Standard No. 108 on the front of a passenger car, and any other four-wheeled vehicle of less than 80 inches overall width. Although Standard No. 108 impose a minimum mounting height of 22 inches on headlamps, it allows parking lamps and turn signal lamps to be mount as low as 15 inches above the road surface which means that they could be mounted in the front bumper, or otherwise close to the mounting location of fog lamps and driving lamps. Therefore, compliance with paragraph S4.1..3 of Standard No. 108 would require a manufacturer of a vehicle equipped with fog and driving lamps to ensure that they do not impair the effectiveness of the headlamps, turn signal lamps, and parking lamps.; Because fog lamps and driving lamps are not covered by Standard No 108, the individual States may have their own restrictions on the mounting height of these lamps. We regret that we are unable to advise you on these laws. However, the American Association of Motor Vehicle Administrators (AAMVA), 1201 Connecticut Ave., N.W., Washington, D.C., may be able to advise you.; Sincerely, Erika Z. Jones, Chief Counsel |
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ID: aiam5440OpenMr. C.N. Littler Motor Coach Industries Administrator Regulatory Affairs 1558 Wilson Place Winnipeg, Manitoba R3T 0Y4 CANADA; Mr. C.N. Littler Motor Coach Industries Administrator Regulatory Affairs 1558 Wilson Place Winnipeg Manitoba R3T 0Y4 CANADA; "Dear Mr. Littler: This responds to your letter concerning whether New York State law addressing the in-use stopping ability of privately owned motor coaches is preempted by Federal law. I apologize for the delay in our response. The New York law states that a vehicle must be capable of stopping 'at a rate of deceleration equivalent to a stop within 22.2 feet from a speed of 20 miles per hour.' You believe that 103(d) of the National Traffic and Motor Vehicle Safety Act ('Safety Act') preempts the New York law, since the state law is not identical to Federal motor vehicle safety standard No. 121, Air Brake Systems. Please note that the Safety Act has been codified at 49 U.S.C. 30101 et seq. and that the citation for 103(d) is now 49 U.S.C. 30103. As explained below, Standard No. 121 currently does not have stopping distance requirements in effect, therefore, the New York law is not currently preempted by a Federal safety standard. Nevertheless, the agency has issued a proposal to reinstate stopping distance requirements in Standard No. 121. (58 FR 11003, February 23, 1993). If the agency issues a final rule to reinstate stopping distances, then any more stringent requirements in the New York law (addressing the same aspects of performance as Standard No. 121) would be preempted. Title 49 U.S.C. 30103 states: Whenever a Federal motor vehicle safety standard ... is in effect, no State or political subdivision of a State shall have any authority either to establish, or to continue in effect, with respect to any motor vehicle or item of motor vehicle equipment any safety standard applicable to the same aspect of performance of such vehicle or item of equipment which is not identical to the Federal standard. That provision preempts New York's law if there is a Federal safety standard in effect, the state law covers the same aspect of performance as that Federal standard, and the State law is not identical to the Federal safety standard. While you are correct that Standard No. 121 refers to stopping performance in S5.3.1, you apparently were not aware of a provision in S3 that states Notwithstanding any language to the contrary, sections S5.3.1, S5.3.1.1, S5.3.2, S5.3.2.1, S5.3.2.2, S5.7.1, S5.7.3(a) and S5.7.3(b) of this standard are not applicable to trucks and trailers, and section S5.3.1 of this standard is not applicable to buses. The agency amended the standard to include this provision as the result of a ruling in PACCAR v. NHTSA, 573 F.2d 632, (9th Cir. 1978), cert. denied, 439 U.S. 862 (1978), in which a Federal Court of Appeals invalidated Standard No. 121's stopping distance requirements until the agency obtains 'more probative and convincing data evidencing the reliability and safety of vehicles that are equipped with antilock.' While the provision did not originally cover buses other than school buses, NHTSA extended the provision to non-school buses in 1987. See 52 FR 20602. Because there are no Federal stopping distance requirements in effect, the New York law is not preempted. As noted above, NHTSA has issued a notice proposing to reinstate stopping distance requirements for air braked vehicles. The agency is currently reviewing comments to that proposal, and may issue a final rule reinstating stopping distance requirements. If the agency decides to amend Standard No. 121 to include such requirements, then any more stringent requirements in the New York law (addressing the same aspects of performance as Standard No. 121) would be preempted. I note that the New York law applies to vehicles in use, while Standard No. 121 applies to new vehicles. In general, State laws governing the operation of vehicles are not preempted by inconsistent Federal motor vehicle safety standards unless the State law is more stringent than the Federal standard (with respect to the same aspect of performance). A more stringent law would be preempted, since it would preclude the sale of vehicles that comply with Federal standards. I also note that the in-use braking performance of many motor coaches is regulated by the Federal Highway Administration. We have referred your letter to that agency's Office of Motor Carrier Standards concerning the issue of whether its regulations preempt the New York law. I hope this information is helpful. If you have any questions about NHTSA's safety standards, please feel free to contact Marvin Shaw at this address or by telephone at (202) 366-2992. If you wish to contact someone in the Federal Highway Administration's Office of Chief Counsel concerning the motor carrier standards, please call Charles Medalen at (202) 366-1354. Sincerely, John Womack Acting Chief Counsel Enclosure "; |
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ID: aiam0255OpenIng. Andrea Catanzano, Automobili Lamborghini, 40019 S. Agata Bolognese (Bologna), Italio; Ing. Andrea Catanzano Automobili Lamborghini 40019 S. Agata Bolognese (Bologna) Italio; Dear Dr. Catanzano: Thank you for your letter of September 23 informing us of lamborghini' continue progress towards compliance with Federal motor vehicle safety standards.; I want to remind you that Standard No.. 211 precludes the use of whee nuts, wheel discs, and hub caps that incorporate winged projections, such as the one shown in the Espada photograph which I enclose. We have seen several Espadas manufactured in 1969 with wheels identical to this one, and were informed in one instance that the winged projections had been shipped form Italy with the car. Such a shipment violates the spirit, if not the letter of Standard No. 211.; There is no charge for the 'Program Plan for Motor Vehicle Safet Standards', enclosed at your request.; Sincerely, Lawrence R. Schneider, Acting Deputy Chief Counsel |
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ID: aiam1787OpenMr. Arthur M. Elson,Acme-Hamilton Manufacturing Corporation,P.O. Box 361,Trenton, New Jersey 08603; Mr. Arthur M. Elson Acme-Hamilton Manufacturing Corporation P.O. Box 361 Trenton New Jersey 08603; Dear Mr. Elson:#Please forgive the delay in responding to your lette of october 4, 1974, requesting information on the labeling of air brake hose with you manufacture.#You have correctly interpreted Federal Motor Vehicle Safety Standard No. 106-74,*Brake Hose*, as requiring labeling identifying Acme-Hamilton as the manufacturer of the hose, and not requiring further labeling identifying your customers. You are permitted to label the hose with optional information, such as your customer's name, in addition to that required by S5.2.2 as incorporated in S7.2 of the Standard. To avoid confusion with the required information, however, the optional information must appear on the opposite side if the hose.#Yours truly,Richard B. Dyson,Acting Chief Counsel; |
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ID: aiam2350OpenMr. Peter W. Mole, Pacet International, 1192 First Avenue, New York, NY 10021; Mr. Peter W. Mole Pacet International 1192 First Avenue New York NY 10021; Dear Mr. Mole:#This is in response to your June 15, 1976, questio whether Arcoflex windshield wiper blades must be certified as being in compliance with Federal motor vehicle safety standards before they may be sold as aftermarket equipment through vehicle distributors' dealer parts programs.#Standard No. 104, *Windshield Wiping and Washing Systems*, requires vehicles to be equipped with a power-driven windshield wiping system that meets specified performance requirements. It is up to vehicle manufacturers to certify that each vehicle they produce conforms to the requirements of Standard No. 104, in accordance with the certification procedures specified in 49 CFR Part 567.#Standard No. 104 is not an equipment standard, however, and is not applicable to wiper blades sold in the aftermarket. Therefore, there is no requirement that Arcoflex windshield wiper blades be certified, so long as they are not installed on vehicles as part of the wiping system prior to the first sale of the vehicle.#Sincerely, Frank A. Berndt, Acting Chief Counsel; |
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ID: aiam3766OpenMr. Pekka Suuronen, Product Development Manager, Racemark International, Inc., P.O. Box 82, Burnt Hills, NY 12027; Mr. Pekka Suuronen Product Development Manager Racemark International Inc. P.O. Box 82 Burnt Hills NY 12027; Dear Mr. Suuronen: This is in reply to your letters of July 27, 1983, and October 6, 1983 asking whether a sealed headlamp with 'replaceable European H4 bulb' or 'Ford bulb (6 standard sizes)' are considered 'legal,' (like Cibie BOBI) 'provided it meets with all the applicable SAE standards.'; Cibie certifies that its 'BOBI' headlamp complies with all applicabl Federal motor vehicle safety standards, pursuant to Section 114 of the National Traffic and Motor Vehicle Safety Act. Thus far, the National Highway Traffic Safety Administration has not contested that certification.; We do not understand your reference to the Ford bulb in '6 standar sizes.' The only size of that bulb that may be used in the new replaceable bulb headlamp systems is the one specified in the recent amendment to Standard No. 108. However, Volkswagen has petitioned for rulemaking to allow the H4 bulb.; Sincerely, Frank Berndt, Chief Counsel |
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ID: aiam5091OpenMr. Chester I. Nielsen, III Vice President Sales Wesbar Corporation P.O. Box 577 West Bend, WI 53095; Mr. Chester I. Nielsen III Vice President Sales Wesbar Corporation P.O. Box 577 West Bend WI 53095; Dear Mr. Nielsen: This responds to your letter of October 21, 1992, t Walter B. McCormick, Jr. (the General Counsel of this Department). You have written for 'further explanation of S5.3.1.1.1 in FMVSS 108.' You have heard that there is an additional interpretation with respect to the location of clearance lamps on boat trailers whose overall width is 80 inches or more, which would allow mounting of these lamps in accordance with a sketch that you enclosed, and you ask for confirmation of this interpretation. We are unaware of any interpretation of this nature. The requirements for the provision and location of clearance lamps on wide boat trailers remain those set forth in Tables I and II of Standard No. 108, with the exceptions set forth in paragraphs S5.1.1.9, S5.3.1.1.1, and S5.3.1.4. Sincerely, Paul Jackson Rice 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.