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: aiam0219OpenMr. D.J. Broom, Technical Manager (C.V.), The Society of Motor Manufacturers and Traders Limited, Forbes House Halkin Street, London SW1, England; Mr. D.J. Broom Technical Manager (C.V.) The Society of Motor Manufacturers and Traders Limited Forbes House Halkin Street London SW1 England; Dear Mr. Broom: Thank you for your letter of February 2, 1970, to the Federal Highwa Administration, Transmitting the August 1969, edition of the S.M.M.T Tyre and Wheel Engineering Manual.; Your letter also expressed your intention of having the 1969 manua supercede the 1965/66 data book as referenced in Section S3 of Standard No. 109. As we stated in our letter of March 14, 1969, to Mr, Woodbridge, Chief Engineer of S.M.M.T, 'Federal Motor Vehicle Safety Standard No. 109, within Section S3, lists the Tyre and Wheel Engineering Data Book dated 1965/66 of the Society of Motor Manufacturers and Traders Limited (S.M.M.T), 'as one of the references containing acceptable test rims. When Standards No. 109 and 110 were developed, the National Highway Safety Bureau accepted the S.M.M.T. 1965/66 Data Book tire and rim combinations based on established usage. We did not, nor do we at present intend to accept general updating of these referenced publications, either foreign or domestic, as valid reasons for amending Standards No. 109 and 110. Consequently, any new tire size designations or alternative rim sizes that you wish to list within Standards No. 109 and 110 will have to comply, on an individual basis, with the abbreviated guidelines as outline in the October 5, 1968, *Federal Register*.; Sincerely, Rodolfo A. Diaz, Acting Associate Director, Motor Vehicl Programs; |
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ID: aiam2224OpenEdward Lacey, Industry Technical Specialist, Laminated Glass, Monsanto Polymers and Petrochemicals Co., 190 Grochmal Avenue, Indian Orchard, MA 01051; Edward Lacey Industry Technical Specialist Laminated Glass Monsanto Polymers and Petrochemicals Co. 190 Grochmal Avenue Indian Orchard MA 01051; Dear Mr. Lacey: This is in response to your letter of December 22, 1975, to Mr. Gu Hunter of my staff, concerning our reasons for prohibiting the use of tempered glass in windshields of motor vehicles.; The use of tempered glass in windshields is prohibited for th following reasons:; >>>1. Tempered glass has little, if any, energy absorbing capabilit while laminated glass has intrinsic deflective characteristics that provide such capability.; 2. When tempered glass breaks, it usually either 'crazes' or shatter into many small pieces. If crazing occurs, the driver's vision becomes obscured thus not only endangering himself but others as well. If the glass shatters, the driver and other vehicle occupants are showered with glass pellets which could not only result in loss of control of the vehicle but is also likely to cause eye injuries.; 3. When cracked, tempered glass has essentially no retentiv capability, thus the likelihood of occupant ejection through the windshield opening is greatly increased in crash situations. Laminated glass, on the other hand, possesses significant retentive capability even after initial cracking of the glass laminate on either side of the plastic interlayer.<<<; If I can be of further help, do not hesitate to contact me. Sincerely, Robert L. Carter, Associate Administrator, Motor Vehicl Programs; |
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ID: aiam3966OpenMs. Melinda Maggs, 243 Washington Ave., Scotia, NY 12302; Ms. Melinda Maggs 243 Washington Ave. Scotia NY 12302; Dear Ms. Maggs: Thank you for your March 25, 1985, letter asking about Federal moto vehicle safety regulations that might affect an aftermarket product you wish to manufacture. You described your product as a pad to cushion safety belts. The pad, which is removable, is made of 1/4 inch foam and is attached with velcro to the safety belt. I regret the delay in our response.; You first asked for confirmation of information received in a phon conversation with Paul Bauer of this office. As Mr. Bauer explained, section 108(a)(2)(A) of the National Traffic and Motor Vehicle Safety Act (Safety Act) may affect the sale of your product. As you requested, I have enclosed a copy of the Act for your reference. That section provides that manufacturers, distributors, dealers, and motor vehicle repair businesses may not render inoperative any safety device installed in accordance with any Federal safety standard. Since safety belts are safety devices installed in accordance with Safety Standards No. 208 and 209, those types of businesses may not install any other products which would impair the effective operation of the belts. Individual consumers may purchase and install additional products in their vehicles or otherwise modify existing equipment, without risk of violating the 'render inoperative' provision.; I should emphasize that we are unable to offer any opinion on whethe your product would impair the effectiveness of safety belts. We do recommend that manufacturers carefully consider that possibility before placing their products on the market.; You also asked whether any Federal regulations relating to materia content and flammability affect your product. Although no Federal Motor Vehicle Safety Standards directly govern material content, Standard No. 302 does provide flammability requirements for components of new vehicle occupant compartments, including safety belts. Thus, your product would need to meet the flammability standard if it was installed as original equipment in new vehicles.; Standard No. 302 would not apply directly to your product if it is sol only as aftermarket equipment. However, section 108(a)(2)(A) of the Safety Act, discussed above, could affect your product as it relates to the flammability standard. NHTSA would consider the installation of safety belt pads that do not meet the requirements of Standard No. 302 as 'rendering inoperative' an element of design (flammability resistance) installed in accordance with an applicable Federal safety standard. Again, this provision prohibits only manufacturers, dealers, distributors, and repair businesses from installing such products, it does not prohibit consumers from purchasing and installing those products on their own.; Again, we are not offering any opinion as to whether your product woul meet those flammability standards, but we recommend that you consider that aspect.; The agency believes that all Federal motor vehicle safety standards ar important and that all manufacturers should strive to meet those standards, whether required by law or not. Additionally, if noncomplying pads were to catch fire in a situation where a pad complying with Standard No. 302 would not have caught fire, a manufacturer might face possible product liability consequences under state law. Likewise, a manufacturer might face product liability consequences if its product impaired the effectiveness of the safety belts. You may wish to consult a local attorney in this regard to discuss your product.; I am enclosing copies of Safety Standards Nos. 208, 209 and 302. W appreciate your interest in devices which may encourage safety belt usage, and I hope this letter has addressed your concerns. If you have any further questions, please feel free to contact me.; Sincerely, Jeffrey R. Miller, Chief Counsel |
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ID: aiam0649OpenMr. Charles R. Matthews, Sr. Safety Engineer, Oshkosh Truck Corporation, P. O. Box 560, Oshkosh, WI 54501; Mr. Charles R. Matthews Sr. Safety Engineer Oshkosh Truck Corporation P. O. Box 560 Oshkosh WI 54501; Dear Mr. Matthews: In your letter of March 13 you ask for an interpretation o certification requirements applicable to remanufactured vehicles.; The National Traffic and Motor Vehicle Safety Act of 1966 and 49 CF Part 567 require only that certification of vehicle conformity be provided prior to the first purchase for purposes other than resale. On the basis of the work that you described as your 'remanufacturing', specifically that the vehicle retains its 'original frame, cab, body, axles, and transmission', we concur in your interpretation that vehicles of this nature are not new vehicles requiring certification of conformity with the Federal motor vehicle safety standards.; Yours truly, Richard B. Dyson, Assistant Chief Counsel |
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ID: aiam2674OpenMr. Joseph A. Labert, President, Sharon Recreation World, Inc., 3960 Union Road, Cheektowaga, NY 14225; Mr. Joseph A. Labert President Sharon Recreation World Inc. 3960 Union Road Cheektowaga NY 14225; Dear Mr. Labert: This is in response to your letter of September 1, 1977, concerning th permissibility of installing hitches which inhibit the shock absorbing capability of vehicle bumpers.; The attachment of hitches to motor vehicle bumpers will not constitut a violation of any Federal motor vehicle safety standard. The testing requirements of the Federal safety standard that applies to bumpers (Standard No. 215, *Exterior Protection*) specify that trailer hitches are to be removed prior to testing for compliance. Thus, it is only necessary that the vehicle comply with the standard when the trailer hitch is not attached.; Sincerely, Joseph J. Levin, Jr., Chief Counsel |
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ID: aiam2361OpenMr. Brian Gill, Assistant Manager, Safety & Environmental Activities, American Honda Motor Co. Inc., P.O. Box 50, 100 W. Alondra Blvd. #Gardena, Calif. 90247; Mr. Brian Gill Assistant Manager Safety & Environmental Activities American Honda Motor Co. Inc. P.O. Box 50 100 W. Alondra Blvd. #Gardena Calif. 90247; Dear Mr. Gill: This is in reply to your letter of July 16,1976, asking for interpretation of S6.1 of Motor Vehicle standards No. 122, *Motorcycle Brake Systems*.; S6 requires the performance requirements of S5 to be met under certai specified conditions. One of these, S6.1, states that the test weight is unloaded vehicle weight plus 200 pounds. You have stated that some Honda motor cycles with limited engine displacement are equipped to carry the driver only and that the recommended vehicles load limit is less than 200 pounds. You have requested an interpretation that will allow Honda to perform tests for Standard No. 122 at unloaded vehicle weight plus 1500 pounds.; There is no requirements that tests be conducted at any specifie weight, only that the performance requirements of Standard No. 122 will be met when the test weight is unloaded vehicle weight plus 150 pounds. Thus Honda may test at unloaded vehicle weight plus 150 pounds and certify compliance with Standard No. 122 as long as it is reasonably certain, (through extrapolation of test results for example) that the vehicle will comply if tested by NHTSA under the condition imposed by S6.1.; I do not know if this interpretation is responsive to your concern. I Honda believes that the 200 pound test condition is impracticable for small motorcycles it may wish to submit a petition for rulemaking to amend S6.1.; Yours truly, Frank Berndt, Acting Chief Counsel |
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ID: aiam3989OpenMr. Mike Landgraf, Land Design Group, 685 Lakebird Dr., Sunnyvale, CA 94089; Mr. Mike Landgraf Land Design Group 685 Lakebird Dr. Sunnyvale CA 94089; Dear Mr. Landgraf: Thank you for your letter of May 21, 1985, concerning Federa regulations that might affect a cargo system for hatch back cars that you are developing. You requested confidentiality for your specific product description and drawing. Since your design has not been marketed as yet, we are granting your request for confidentiality. The following discussion provides an explanation of how our standards would affect a device such as yours.; The National Traffic and Motor Vehicle Safety Act authorizes our agenc to issue Federal Motor Vehicle Safety Standards that apply to new motor vehicles and items of motor vehicle equipment. We have not issued any standard that directly applies to a cargo system such as yours. However, use of your system could be affected by Standard No. 111, *Rearview Mirrors*, which sets performance requirements for rearview mirrors, a copy of the standard and an information sheet discussing the responsibilities of vehicle and equipment manufacturers under our regulations is enclosed for your reference.; Standard No. 111 provides that each inside rearview mirror must provid a specified field of view to the rear of the vehicle. If the field of view of the inside mirror in a new vehicle is obstructed by anything other than head restraints or seated occupants, then an outside rearview mirror must be provided on the passenger's side of the vehicle. Thus, if your product were installed in a new vehicle by a manufacturer or dealer prior to its sale to a consumer, and if installation of your product would mean that the inside rearview mirror would no longer comply with the applicable field of view requirements, they would have to ensure the vehicle was equipped with the necessary additional mirror required by Standard No. 111.; In 1974, Congress amended the National Traffic and Motor Vehicle Safet Act to address the problem of persons tampering with safety equipment installed on a motor vehicle by adding section 108(a)(2)(A) to the Act. That section provides, in part, that:; >>>No manufacturer, distributor, dealer, or motor vehicle repai business shall knowingly render inoperative, in whole or in 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 . . . .<<<; Thus, if a manufacturer, distributor, dealer, or motor vehicle repai business adds your product to a used vehicle and if its installation would mean that the inside rearview mirror would no longer comply with the applicable field of view requirements, they would have to install an outside passenger side mirror. Section 108(a)(2)(A) does not establish any limitations on an individual vehicle owner's ability to alter his or her own vehicle. Thus, under Federal law, individual vehicle owners can themselves install any equipment they want on their vehicles, regardless of whether that equipment would render inoperative the compliance of the vehicle with the performance requirements of Standard No. 111. They would, of course, still have to comply with any applicable State laws.; I hope this information is of assistance to you. If you have furthe questions, please let me know.; Sincerely, Jeffrey R. Miller, Chief Counsel |
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ID: aiam3823OpenMr. William Shapiro, Manager, Regulatory Affairs, Volvo of America Corporation, Rockleigh, NJ 07647; Mr. William Shapiro Manager Regulatory Affairs Volvo of America Corporation Rockleigh NJ 07647; Dear Mr. Shapiro: This is in response to your letter of March 23, 1984, petitioning th Administrator for a temporary exemption from Motor Vehicle Safety Standard No. 213, *Child Restraint Systems*, to allow use of the Volvo Child Safety Seat in 2500 of Volvo's 240/260 series vehicles.; Section 123 of the National Traffic and Motor Vehicle Safety Ac provides authority to exempt only motor vehicles from compliance with any applicable motor vehicle safety standard. This authority does not extend to individual items of motor vehicle equipment. Inasmuch as Standard No. 213 specifies requirements for child seating systems for use in motor vehicles but does not require their installation in them as original equipment, it is considered an equipment standard, rather than a vehicle standard. This means that the agency has no authority to grant your petition for exemption. If you wish to pursue this matter further, you may submit a petition for rulemaking pursuant to 49 CFR Part 552 to amend Standard No. 213 in a manner that would allow the Volvo seat.; Sincerely, Frank Berndt, Chief Counsel |
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ID: aiam2731OpenMr. R. W. Hildebrandt, Group Director of Engineering, The Bendix Corporation, 901 Cleveland Street, Elyria, OH 44035; Mr. R. W. Hildebrandt Group Director of Engineering The Bendix Corporation 901 Cleveland Street Elyria OH 44035; Dear Mr. Hildebrandt: This responds to Bendix Corporation's November 9, 1977, request fo confirmation that S5.6.4 of Standard No. 121, *Air Brake Systems*, does not prohibit the use of a two-valve sequential means to release the parking brakes on a towed vehicle.; I have enclosed for your information two interpretations that addres this question, stating that a two- valve sequential release is permissible under S5.6.4. I have also enclosed a copy of an outstanding rulemaking proposal that would standardize the parking brake control as specified in the Society of Automotive Engineers Recommended Practice J680b. I am unable to advise you whether the National Highway Traffic Safety Administration intends to make final this proposal.; I would also like to remind you of the requirement in S5.6.4 tha '[t]he control shall be identified in a manner that specifies the method of control operation.' So long as different control arrangements are used, it is critical that the means of operation be clearly marked.; Joseph J. Levin, Jr. |
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ID: aiam3570OpenMr. Jeff Wimer, P.O. Box 152, Auburn, IN 46706; Mr. Jeff Wimer P.O. Box 152 Auburn IN 46706; Dear Mr. Wimer:#This responds to your phone request of June 11, 1982 concerning Federal motor vehicle safety standards that apply to motorcycle sidecars sold as aftermarket motor vehicle equipment.#While there are no 'sidecar' standards, certain of the items of equipment that may be found in sidecars are covered by Federal equipment safety standards. Specifically, brake hoses, lighting equipment, tires, rims, and glazing materials (if provided) would have to comply with Standards Nos. 106, 108, 119, 120 and 205. I have enclosed an information sheet explaining how you can obtain copies of the agency's safety standards.#Because a sidecar itself is an item of motor vehicle equipment, the manufacturer of any sidecar sold in the aftermarket would be responsible for notification and remedy in the event the product was determined to contain a safety-related defect.#If you have any further questions, please let me know.#Sincerely, Frank Berndt, 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.