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
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ID: aiam5088OpenMr. Thomas Price ABAS Marketing, Inc. P.O. Box 5644 Norman, OK 73070; Mr. Thomas Price ABAS Marketing Inc. P.O. Box 5644 Norman OK 73070; "Dear Mr. Price: This responds to your letter asking about requirement for a device you call a 'noncomputerized antilock braking assist system,' for brakes installed on trucks and trailers. You stated that your device can be installed on vehicles equipped with air brake, electric brake, air over hydraulic brake, and vacuum/hydraulic brake systems. I am pleased to have this opportunity to explain our regulations to you. You asked what the agency's policy is regarding the approval, disapproval, or certification of any particular antilock brake system product. NHTSA does not provide approvals of motor vehicles or motor vehicle equipment. Under the National Traffic and Motor Vehicle Safety Act ('Safety Act'), it is the responsibility of the manufacturer to ensure that its vehicles or equipment comply with applicable standards issued by this agency. A manufacturer then certifies that its vehicles or equipment comply with applicable standards. You also asked for a listing of the various standards and regulations with which you should be conversant, given your product, and an explanation of the responsibilities under the Safety Act of three types of parties: an original equipment manufacturer, an alterer of a previously certified new motor vehicle prior to its first sale, and an installer of an ABS device on a used motor vehicle. NHTSA has issued two standards about brake systems: Standard No. 105, Hydraulic Brake Systems and Standard No. 121, Air Brake Systems. Standard No. 105 specifies requirements for hydraulic service brake and associated parking brake systems, and applies to new passenger cars, multipurpose passenger vehicles, trucks, and buses equipped with hydraulic brake systems. Standard No. 121 establishes performance and equipment requirements for braking systems on vehicles equipped with air brake systems, and applies to almost all new trucks, buses, and trailers equipped with air brake systems. The agency does not have a regulation specifically covering a device such as a 'noncomputerized antilock braking assist system' which is added to a brake system. However, since your device would be tied into a vehicle's brake system, it could affect a vehicle's compliance with Standard No. 105 and Standard No. 121. If one of your devices is installed as original equipment on a new vehicle, the vehicle manufacturer is required to certify that, with the device installed, the vehicle satisfies the requirements of all applicable safety standards, including Standard No. 105 and Standard No. 121. (See 15 U.S.C. 1397(a)(1) and 49 CFR Part 567.) If the device is added to a previously certified new motor vehicle prior to its first sale, the person who modifies the vehicle would be an alterer of a previously certified motor vehicle and would be required to certify that, as altered, the vehicle continues to comply with all of the safety standards affected by the alteration. (See 49 CFR Part 567.7.) If the device is installed on a used vehicle by a business such as a garage, the installer would not be required to attach a certification label. However, it would have to make sure that it did not knowingly render inoperative, in whole or part, any device or element of design installed on or in a motor vehicle or item of motor vehicle equipment in compliance with an applicable Federal motor vehicle safety standard. (See 15 U.S.C. 1397(a)(2)(A).) You should also be aware of the requirements of Safety Standard No. 106, Brake Hoses, which specifies requirements for motor vehicle brake hose, brake hose assemblies, and brake hose end fittings. That standard applies to new motor vehicle equipment as well as to new motor vehicles. You should check to see if any parts of your devices are subject to the requirements of Standard No. 106. I also note that manufacturers of aftermarket equipment are subject to the Safety Act's defect provisions. Should a safety-related defect be discovered in your device, whether by the agency or yourself, you as the manufacturer would be required to notify purchasers and dealers and provide a cost-free remedy for the defect. Enclosed is a copy of an information sheet entitled 'Information for New Manufacturers of Motor Vehicles and Motor Vehicle Equipment,' which further explains a manufacturer's responsibilities under NHTSA's regulations. You may also wish to review the Federal Highway Administration's Federal Motor Carrier Safety Regulations, which set forth requirements for commercial motor vehicles. The address of the Office of Motor Carrier Standards is included in the enclosed information sheet. Finally, you asked how you could secure or have access to the complete Docket No. 92-29-01. This docket includes responses to an advance notice of proposed rulemaking (ANPRM) in which NHTSA announced that it is considering proposing additional requirements that might require medium and heavy duty vehicles to be equipped with antilock brake systems. The complete docket, including all the responses to the ANPRM, can be reviewed at the agency's Docket Section, room 5109, 400 Seventh Street, S.W., Washington D.C. 20590. Docket hours are 9:30 a.m. and 4:00 p.m., Monday through Friday. A complete copy of the docket is also available for a fee to cover search and copying costs by contacting the agency's technical reference division at (202) 366-4949. I hope this information is helpful. If you have any further questions about NHTSA's safety standards, please feel free to contact Marvin Shaw of my staff at this address or by telephone at (202) 366-2992. Sincerely, Paul Jackson Rice Chief Counsel Enclosure"; |
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ID: aiam0265OpenMr. B. Borisoff, Consulting Engineer, 5403 Blanco Avenue, Woodland Hills, CA 91364; Mr. B. Borisoff Consulting Engineer 5403 Blanco Avenue Woodland Hills CA 91364; Dear Mr. Borisoff: Reference is made to your letter of October 14, 1970 to Secretary Volp regarding our Consumer Information publication.; Concerning your comments on stopping distance, the wording used on pag 4 is the exact wording of this regulation. The category 'Stopping distance in feet with emergency brakes (partial service brake system)' is a generalization of the regulatory wording meant to convey the sense of this requirement to a consumer who may have no engineering background. The paragraph on page 193 paraphrases the regulatory wording. The title 'Partial Failure on One System' is, again, meant to convey the meaning to an otherwise uninformed consumer. I trust this clarifies the situation for you.; The reason many motorcycles are not listed is the fact that the dat was not received in time to be included in the book. I am enclosing copies of the data available for U.S. made motorcycles as you requested.; Volume 2, covering the 1971 makes and models will be availabl approximately November 15, 1970 and can be obtained from the Government Printing Office at a cost of $2.00. In addition two (2) new Consumer Aid publications entitled 'BRAKES - A Comparison of Braking Performance for 1971 Passenger Cars' and 'TIRES - A Comparison of Tire Reserve Load for 1971 Passenger Cars' will also be available at a cost of $.40 each.; Many thanks for your kind words and your interest in our motor vehicl safety program.; Sincerely, Rodolfo A. Diaz, Acting Associate Director, Motor Vehicl Programs; |
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ID: aiam2258OpenMr. T. Albert Yamada, Masaoka-Ishikawa and Associates, Inc., Suite 520, The Farragut Building, 900 Seventeenth Street, N.W., Washington, DC 20006; Mr. T. Albert Yamada Masaoka-Ishikawa and Associates Inc. Suite 520 The Farragut Building 900 Seventeenth Street N.W. Washington DC 20006; Dear Mr. Yamada: This responds to your February 24, 1976, request for affirmation that particular Takata Kojyo test procedure for applying force to a continuous loop Type 2 belt system meet[s] the requirements set forth in Standard 209, Seat Belt Assemblies.'; Section S4.4 of Standard No. 209 sets forth the requirements of th standard for assembly performance. Section S5.3(b) sets forth test methods that would be used in a determination of whether a Type 2 seat belt assembly conforms to the requirements of S4.4. Takata Kojyo's obligation as a manufacturer is to ensure that its certification of compliance is not false or misleading in a material respect, and that it has exercised due care in manufacturing to conform to Standard No. 209 (15 U.S.C. S 1397 (b) (2)). A manufacturer is not required to follow specifically the test procedures of the standards, but to ascertain, in the exercise of due care, that its product will conform to the standard's requirements when it is tested by the stated methods.; From your description, you have modified the existing procedures by us of a clamp to ensure that all force is applied to the lower torso webbing and hardware or, alternatively, to the upper torso webbing and hardware. While it appears that the contemplated test procedure may evidence the exercise of due care to certify compliance with S4.4, the NHTSA cannot approve a manufacturer's test procedure as the basis of due care in advance of the actual events that underlie certification. It is the manufacturer's responsibility to utilize sound engineering judgment in the exercise of due care.; Sincerely, Frank Berndt, Acting Chief Counsel |
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ID: aiam5067OpenMs. Patti Aupperlee 5961 St. Barbara St. West Palm Beach, FL 33415; Ms. Patti Aupperlee 5961 St. Barbara St. West Palm Beach FL 33415; "Dear Ms. Aupperlee: This responds to your letter asking about th Federal requirements that apply to the 'Cool Cover,' an accessory for child restraint systems. According to your letter, the purpose of the Cool Cover is to prevent a restraint system from becoming so hot from sun and heat in a vehicle that it can burn a child. The Cool Cover would shield the restraint while the restraint is not being used. You explain that when the restraint is used, the Cool Cover can be partially stored in a pouch. The pouch would be positioned at the top of the restraint for the child to use as a pillow. By way of background information, 103 of the National Traffic and Motor Vehicle Safety Act ('Safety Act,' 15 U.S.C. 1392) authorizes NHTSA to issue safety standards for new motor vehicles and new items of motor vehicle equipment. NHTSA does not, however, approve or certify any vehicles or items of equipment. Instead, the Safety Act establishes a 'self-certification' process under which each manufacturer is responsible for certifying that its products meet all applicable safety standards. The agency periodically tests vehicles and items of equipment for compliance with the standards. In response to your question, there are currently no Federal motor vehicle safety standards (FMVSS) that directly apply to the product you wish to manufacture. Under the authority of the Safety Act, NHTSA has issued Standard No. 213, Child Restraint Systems, which specifies requirements for child restraint systems used in motor vehicles and aircraft. However, Standard No. 213 applies only to new child restraint systems and not to aftermarket components of a child restraint system, such as an aftermarket cover for the restraint. I note, however, that there are other Federal laws that indirectly affect your manufacture and sale of the Cool Cover. Under the Safety Act, your product is considered to be an item of motor vehicle equipment. As a manufacturer of motor vehicle equipment, you are subject to the requirements in 151-159 of the Safety Act concerning the recall and remedy of products with safety related defects. I have enclosed an information sheet that briefly describes those responsibilities. In the event that you or NHTSA determines that your cover contains a safety-related defect, you would be responsible for notifying purchasers of the defective equipment and remedying the problem free of charge. Manufacturers, distributors, dealers, and motor vehicle repair businesses are subject to 108(a)(2)(A) of the Safety Act, which states: 'No manufacturer, distributor, dealer, or motor vehicle repair business shall knowingly render inoperative ... any device or element of design installed on or in a motor vehicle or item of motor vehicle equipment in compliance with an applicable Federal motor vehicle safety standard ....' It appears unlikely from the nature of your product that it would be placed in vehicles by persons in the aforementioned categories. However, if your product were to be installed by these persons, they should ensure that its installation does not compromise the safety protection provided by a child restraint system. A child restraint has elements of design that could be rendered inoperative by the Cool Cover. Standard No. 213 sets flame-retardant performance requirements for materials used in a child restraint system. (See S5.7 of Standard No. 213, referencing Standard No. 302, 'Flammability of Interior Materials.') Installation of rapidly burning materials could vitiate the compliance of the child restraint with Standard No. 213. Also, Standard No. 213 sets crash performance requirements for all new child restraint systems. Persons in the categories listed in 108(a)(2)(A) would have to ensure that the Cool Cover does not impair the function of the restraint's belts or other operating parts. (We note the statement in your letter that the Cool Cover does not impair the restraint's belts, etc.) Section 109 of the Safety Act specifies a civil penalty of up to $1,000 for each violation of 108. The 'render inoperative' prohibition of 108(a)(2)(A) does not apply to the actions of vehicle owners in adding to or otherwise modifying their vehicles or items of motor vehicle equipment. Thus, if the Cool Cover were placed on restraints by the restraint owners, your product need not meet any FMVSS. Nevertheless, in the interest of safety, we suggest you consider conforming your product to a flammability resistance standard equivalent to Standard No. 302. Also, you might consider providing consumer instructions that would reduce the likelihood that the Cool Cover might be used in a way that could interfere with the safety of the restraint. This might include an instruction on how to position the Cool Cover so that the restraint's belts would perform properly in a crash. I hope this information is helpful. If you have further questions, please contact Deirdre Fujita of my staff at (202) 366-2992. Sincerely, Paul Jackson Rice Chief Counsel Enclosure"; |
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ID: aiam1927OpenMr. H. Miyazawa, Stanley Electric Co., Ltd., 2-9-13 Nakameguro, Meguro-Ku, Tokyo 153, Japan; Mr. H. Miyazawa Stanley Electric Co. Ltd. 2-9-13 Nakameguro Meguro-Ku Tokyo 153 Japan; Dear Mr. Miyazawa: This responds to your letter of May 15, 1975, regarding Federal Moto Vehicle Safety Standard (FMVSS) No. 108 requirements for Type 1A and 2A automotive headlamps.; The following answers are provided for your specific questions: >>>1. FMVSS No. 108 would not prohibit use of metal-back Types 1A an 2A headlamps that conform to all requirements of the standard.; 2. The National Highway Traffic Safety Administration does not issu approvals on automotive equipment. The equipment manufacturer self certifies that the equipment conforms to the applicable FMVSS. The various states may, however, require equipment approval. Information on these approvals may be obtained from the America Association of Motor Vehicle Administrators, 1201 Connecticut Avenue, Washington, D. C. 20036.; 3. The drawings of the Type 1A and 2A headlamp submitted with you letter, indicate that aiming pads have been deleted. Aiming pads are required by FMVSS NO. 108.<<<; For your information enclosed is a copy of FMVSS No. 108, whic includes requirements for Types 1A and 2A headlamps, and a copy of Docket No. 75-8, Notice 1, that proposes to allow use of the four-lamp rectangular systems indefinitely.; Sincerely, E. T. Driver, Director, Office of Crash Avoidance, Moto Vehicle Programs; |
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ID: aiam0635OpenMr. Preston W. Grace, White River Distributors, Inc.; Mr. Preston W. Grace White River Distributors Inc.; Dear Mr. Grace: This is in reply to your letter of March 6, 1972, forwarded to us b Tom Pieratt, wherein you discuss certain situations which have arisen regarding the GVWR of chassis you have purchased for completion by adding bodies.; As far as I can determine from the facts you provided in you letter the chassis manufacturers are doing nothing that is contrary to our regulations. Your complaints seem to be that (a) some chassis that you believe to be identical bear differing weight ratings in their accompanying literature, and (b) you have received some chassis that do not have the weight ratings that you want and believed you were ordering. Both problems appear to be matters of communication between you and the manufacturers or their dealers, which might be resolvable by clearly specifying the desired weight ratings in your purchase order.; Your general statements concerning the effect of the Vehicle Safety Ac and the regulations issued thereunder are essentially correct.; Yours truly, Richard B. Dyson, Assistant Chief Counsel |
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ID: aiam2608OpenMr. Chester J. Barecki, Vice President - Sales Engineering, American Seating Company, 901 Broadway Avenue, N. W., Grand Rapids, MI 49504; Mr. Chester J. Barecki Vice President - Sales Engineering American Seating Company 901 Broadway Avenue N. W. Grand Rapids MI 49504; Dear Mr. Barecki: This responds to your March 24, 1977, letter asking for a interpretation of the requirements for knee contact area in Standard No. 222, *School Bus Passenger Seating and Crash Protection*, which state that, when impacted, 'the resisting force of the impacted material shall not exceed 600 pounds and the contact area on the knee form surface shall not be less than 3 square inches.' You ask whether this requirement can be interpreted as meaning that, when impacted, the resisting force of the impacted material shall not exceed 200 pounds per square inch rather than 600 pounds over 3 square inches.; The 600 pound maximum force and the 3 square inch minimum contact are are two distinct requirements. The first specifies an upper bound on the load that will be applied to the upper leg while the latter specifies a lower bound on the knee area over which an impact load must be distributed. To combine the two requirements, as you suggest, tends to relax the contact area requirement for a load which is less than 600 pounds. Such an interpretation would not ensure the level of safety the agency demands for knee contact area. The suggested combination of the two requirements may not provide an adequate distribution of forces over the knee. Accordingly, the agency declines to accept the suggested interpretation of the standard.; Sincerely, Joseph J. Levin, Jr., Chief Counsel |
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ID: aiam5437Open"M. Guy Dorleans Legal Compliance Department Valeo Vision 34, rue St-Andr 93012 Bobigny Cedex France"; "M. Guy Dorleans Legal Compliance Department Valeo Vision 34 rue St-Andr 93012 Bobigny Cedex France"; Dear M. Dorleans: We have received your letter of July 15, 1994, askin whether certain front lamp designs would be permissible under Federal Motor Vehicle Safety Standard No. 108. In the basic front lamp design, the upper beam photometrics of Figure 17A would be provided by Lamps A and B. You have asked whether it is possible to add Lamp D, 'an auxiliary driving beam.' In this variation 'all three A, B and D filaments would be permanently energized together in high beam mode and table 17a (sic) of FMVSS 108 is then fulfilled.' Lamp D meets the photometric requirements of SAE Standard J581 JUN89 Auxiliary Driving Lamps. The photometrics of Figure 17A apply to two-lamp integral beam or two-lamp combination headlighting systems, and the design in your drawing is that of a four-lamp system, subject to the photometrics of Figure 15A. This configuration is not permissible under Standard No. 108. Sincerely, John Womack Acting Chief Counsel; |
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ID: aiam3449OpenKen Siemens, Metropolitan Property and Liability Insurance Company, Midwest Service Office, 9797 Springboro Pike, P.O. Box 48020, Dayton, OH 45448; Ken Siemens Metropolitan Property and Liability Insurance Company Midwest Service Office 9797 Springboro Pike P.O. Box 48020 Dayton OH 45448; Dear Mr. Siemens: This is in response to your letter of June 25, 1981, requesting listing of those states whose certificates of title have been approved by the agency for use in lieu of the separate Federal odometer form.; The Odometer Disclosure Requirements (49 CFR Part 580) provide that th transferor of a vehicle may make the disclosure required by the Federal odometer laws on the state certificate of title, if the state title document contains essentially the same information required on the Federal odometer disclosure statement. If the information contained on the state certificate of title varies from that required by the Federal form, the statemust obtain the approval of this agency before its certificate of title can be used as a substitute for the Federal form.; In order to spare states the burden of an apporval (sic) process th agency has indicated that certain variations from the Federal form are acceptable. In the *Federal Register* notice of August 1, 1977, which amended the disclosure regulation, we gave examples of shortened forms that would be acceptable. A state title can be considered to be approved for use as a full disclosure statement if it varies from the Federal form in only those aspects noted in the August 1, 1997, notice, a copy of which is enclosed.; The following states have odometer statements on their motor vehicl title forms that are consistent with the requirements of the Federal law:; >>>Maryland, Pennsylvania Massachusetts, Hawaii Michigan, New York Minnesota, North Dakota Ohio>>> In addition, the following states submitted title forms to the agenc asking for approval but had unacceptable statements. Each state was advised that before its form could be approved certain additional information was required on its certificate of title. We do not know whether that information has been included on the titles.; >>>North Carolina, Virginia Delaware, Washington South Dakota, Utah South Carolina, Wisconsin Indiana If you have any further questions, please do not hesitate to write. Sincerely, David W. Allen, Assistant Chief Counsel |
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ID: aiam1474OpenMr. Richard H. King, Gracey, Maddin, Cowan & Bird, 500 Court Square Building, 300 James Robertson Parkway, Nashville, TN 37201; Mr. Richard H. King Gracey Maddin Cowan & Bird 500 Court Square Building 300 James Robertson Parkway Nashville TN 37201; Dear Mr. King: Your letter of April 2, 1974, to Mrs. Winifred Desmond has bee referred to this office for reply. In your letter you discuss what you consider to be an omission in the National Traffic and Motor Vehicle Safety Act, viz., requirements for manufacturers to provide sufficient parts for the repair of vehicles in the hands of purchasers when those vehicles are found to contain safety related defects.; You are correct in stating that the National Traffic and Motor Vehicl Safety Act does not require manufacturers to provide sufficient parts for the repair of defective vehicles in the hands of purchasers. The statute limits manufacturers' responsibilities, as you point out, to notification of owners.; The NHTSA has, however, taken some regulatory steps which relate to th availability of repair parts. The 'Defect Notification' regulations (49 CFR Part 577) require manufacturers to estimate and specify in the defect notification letter the day by which repair parts will be available (49 CFR 55 577.4(e)(1)(ii), 577.4(e)(2)(iii), 577.4(e)(3)(iii)). While this does not require repair parts to be available, it at least prohibits manufacturers from keeping purchasers 'in the dark' on the availability of repair parts. Knowingly incorrect statements in response to this requirement can subject a manufacturer to civil penalties and other sanctions.; There are pending in the Congress amendments to the National Traffi and Motor Vehicle Safety Act (S. 355, 93rd Cong., 1st Sess. (1973), H.R. 5529, 93rd Cong., 1st Sess. (1973)) that would in general require manufacturers to repair vehicles found to contain safety related defects without charge to the vehicle purchaser. If such legislation is enacted it would eliminate the problem of the availability of repair parts where safety related defects are found to exist.; We are pleased to be of assistance. Sincerely, Lawrence R. Schneider, 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.