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: aiam2993OpenMr. Michael Petler, Assistant Manager, Safety and Legislation Department, U.S. Suzuki Motor Corporation, 13767 Freeway Drive, Santa Fe Springs, California 90670; Mr. Michael Petler Assistant Manager Safety and Legislation Department U.S. Suzuki Motor Corporation 13767 Freeway Drive Santa Fe Springs California 90670; Dear Mr. Petler: This is in response to your request of March 22, 1979, for a interpretation of Federal Motor Vehicle Safety Standard No. 109. First, I would like to apologize for the delay in responding to your request of September 14, 1978. As was explained to you in a telephone conversation on March 22, your letter and the response thereto was apparently lost when the Chief Counsel's offices were moved. Although we took great care to ensure that something like this would not happen, it seemingly did in this case. I regret this and hope that it has not caused any undue inconvenience for your company.; You asked whether it was permissible under Standard 109 for manufacturer to stamp the maximum permissible inflation pressure of a tire and its maximum load rating on the tire in both English units (pounds and psi) and metric units (kilograms and kPa). S4.3(b) and (c) of the standard specify that each tire shall have permanently molded onto the sidewalls the maximum load rating for the tire. This agency has interpreted this requirement to mean that the information must appear on the sidewalls in the English units, since this is the system of measurement which will be used and understood by most consumers. However, so long as the information appears in English units, there is no reason that it could not also be the additional information does not cause confusion about the required information. By stating not only the pressure and rating values, but also the units of value, your company would avoid causing any such confusion. Therefore, the expression of inflation pressure and load rating in English and metric units as shown in your illustration is permissible under Standard 109.; Sincerely, Frank Berndt, Acting Chief Counsel |
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ID: aiam3681OpenMr. K. Inoue, National Technical Service Manager, Toyo Tire Corporation, Compton, CA 90221; Mr. K. Inoue National Technical Service Manager Toyo Tire Corporation Compton CA 90221; Dear Mr. Inoue: This responds to your February 16, 1983, letter to Joseph Innes of thi agency regarding permissible methods for displaying Uniform Tire Quality Grading (UTQG) information on the sidewall of tires. Your first proposed alternative would delete the treadwear grade number, but not the word 'TREADWEAR' itself, from the format established in Option 3 of Figure 1, 49 CFR 575.104. The second proposed alternative would delete both the word 'TREADWEAR' and the numerical grade from the format specified in Option 3, Figure 1. Your proposed alternatives would be used only on tires produced in molds manufactured before August 8, 1983.; In the agency's February 7, 1983, notice suspending the treadwea portion of the UTQGS, tires produced in molds manufactured prior to August 8 were required to display UTQG information on tire sidewalls in one of the formats specified in Figure 1 or in Figure 6 of 49 CFR 575.104. Your first proposed alternative is clearly different from each of the permitted formats. The permitted formats require either that the word 'TREADWEAR' must appear next to the treadwear grade on the tire, or neither the word nor the numerical grade must appear. Your first alternative could confuse tire purchasers, since the display format could be interpreted as attributing the grade which appears after the work (sic) 'TRACTION' to both the treadwear and traction performance of the tire. Therefore, your first proposed alternative would not be permitted under 49 CFR 575.104.; Your second proposed alternative is quite similar to one permitte format, Option 3 in Figure 6. The only difference between your second alternative and Option 3 is that the traction information is centered in the format in Option 3, while it is slightly off-center in your alternative. Your second alternative should in no way be misleading to tire purchasers, however. Further, nothing in our regulations specifies precise centering of the traction information.; Any inconsistency between your proposed format and the permitted one i so small that the agency would, as a matter of prosecutorial discretion, make no attempt to enforce the UTQGS format requirement when your second alternative is used.; If you have further questions on this matter, please contact us. Sincerely, Frank Berndt, Chief Counsel |
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ID: aiam4144OpenMr. Greg Burns, Quality Manager, Sierracin/TransTech, 12780 San Fernando Road, Sylmar, CA 91342; Mr. Greg Burns Quality Manager Sierracin/TransTech 12780 San Fernando Road Sylmar CA 91342; Dear Mr. Burns: Thank you for your letter of March 7, 1986, to Edward Jettner of thi agency. Your letter was referred to this office for reply. You asked about the effect of the certification requirements of Standard No. 205, *Glazing Materials*, on a product you are planning to manufacture. I hope the following discussion answers your questions.; You described your product as an aftermarket personal securit specialty glazing for automotive use. The glazing would be manufactured by adding a special plastic to the interior surface of a piece of new glazing. You explained that you are having testing conducted on your product and believe that it will pass all of the requirements set for glass-plastic glazing (item AS-14) in Standard No. 205. Your specific question concerns how the glazing is to be marked in accordance with S6 of the standard.; You explained that a new item of glazing is sent to you by an origina equipment glazing manufacturer, who has certified the glazing as complying with the standard and placed the necessary markings, required by S6 of the standard, on the glazing. You asked whether you should obliterate the OEM markings through sandblasting or other means and then apply your own identification or whether you should retain the OEM marking and add additional information to indicate that the glazing has been modified.; S6.1 of Standard No. 205 requires prime glazing manufacturers to mar glazing materials in accordance with section 6 of ANS Z-26. S6.1 further defines a prime glazing manufacturer as one 'who fabricates, laminates, or tempers the glazing material.' In general, an item of glazing has only one prime glazing manufacturer, since usually one manufacturer performs the fabrication, lamination, or tempering of the glazing material. However, in the case of your product, we would consider both the original manufacturer of the glazing and your company, which laminates a plastic material to the glazing, to be prime glazing manufacturers. Both companies are performing a fundamental manufacturing operation, such as fabricating, laminating, or tempering, necessary to produce a completed item of glazing material, as compared to a situation where a company is performing a minor finishing operation, such as polishing, to an item of glazing that is fabricated, laminated, or tempered by another company.; As you pointed out in your letter, having two identifying marks on on item of glazing could lead to potential confusion as to which mark is correct. One of the purposes of the certification requirement is to assist in identifying the responsible manufacturer for the purposes of defect and noncompliance recall campaigns. Thus, in the case of your product, the agency believes that it is important that both prime glazing manufacturers be identified on the glazing since, for example, there could be a noncompliance in the original glazing sent to you or there could be a noncompliance in the glazing as modified by your company. To avoid potential confusion about what item number applies to your finished product, we agree that adding wording to your marking indicating that the original glazing has been modified from one AS item to another will help avoid confusion.; If you have any further questions, please let me know. Sincerely, Erika Z. Jones, Chief Counsel |
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ID: aiam4451OpenMs. Laura C. Boniske 2928 Coconut Grove Drive Coral Gables, FL 33134; Ms. Laura C. Boniske 2928 Coconut Grove Drive Coral Gables FL 33134; "Dear Ms. Boniske: This responds to your letter asking for a interpretation of the requirements of Standard No. 302, Flammability of Interior Materials, as they apply to 'materials used in the manufacture of an aftermarket product which will be utilized in the occupant compartment of a vehicle.' In an October 27, 1987 telephone conversation with Ms. Hom of my staff, you mentioned in particular an item of equipment consisting of a pad for cushioning safety belts. Generally speaking, items of motor vehicle equipment are not covered by Standard No. 302. Standard No. 302 is a vehicle standard and as such applies to completed vehicles. No vehicle can be manufactured unless the materials used in it comply with the requirements of the standard. The general rule is that aftermarket products may be added to vehicles, even if the addition of those products causes the vehicle to no longer comply with the requirements of Standard No. 302, without violating the requirements of Federal law. This general rule is, however, limited by the application of the provisions of Section 108(a)(2)(A) of the National Traffic and Motor Vehicle Safety Act (copy enclosed). That section specifies: '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 . . .' 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. Thus, a manufacturer, distributor, dealer, or motor vehicle repair business that installed a safety belt pad which did not comply with the flammability resistance requirements of Standard No. 302 would be rendering inoperative that element of design, and thereby violating section 108(a)(2)(A) of the Safety Act. We note also that, since safety belts are safety devices installed in accordance with Safety Standards No. 208, Occupant Crash Protection, and No. 209, Seat Belt Assemblies, those commercial businesses would be prohibited from installing the safety belt pad if its installation would impair the effective operation of the belts. Section 109 of the Act specifies a civil penalty of up to $1,000 for each violation of /108. The prohibitions of /108(a)(2)(A) do not apply to the vehicle owner rendering inoperative some element of design in his or her vehicle. Therefore, aftermarket safety belt pads may be sold to a vehicle owner for installation in his or her vehicle regardless of whether the pad complies with the flammability resistance requirements of Standard No. 302. There are two factors which ought to be considered by the manufacturers of safety belt pads which do not satisfy the flammability resistance requirements of Standard No. 302. First is the possibility of liability under State and common law if those pads were to catch fire in a situation where a pad complying with Standard No. 302 would not have caught fire, or if those pads burn much more rapidly than pads that comply with Standard No. 302. Second is the possibility of a finding of a safety-related defect in your products. Sections 151-154 of the Safety Act require that, when an item or motor vehicle equipment contains a safety-related defect, the manufacturer of the item must recall and repair or replace the defective equipment without charge to the purchaser. In any event, we urge you to ensure that your products would not negatively affect the safety provided by the underlying belt assembly. I hope this information is helpful. Please contact us if you have further questions. Sincerely, Erika Z. Jones Chief Counsel Enclosure"; |
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ID: aiam3394OpenMr. M. Iwase, Manager, Technical Administration Dept., Koito Manufacturing Co., Ltd., Shizuoka Works, 550, Kitawaki, Shimizu- Shi, Shizuika-Ken, Japan; Mr. M. Iwase Manager Technical Administration Dept. Koito Manufacturing Co. Ltd. Shizuoka Works 550 Kitawaki Shimizu- Shi Shizuika-Ken Japan; Dear Mr. Iwase: This is in reply to your letter of February 12, 1981, asking whethe the placement of a clear lens cover in front of a motorcycle headlamp would be permissible under Federal Motor Vehicle Safety Standard No. 108.; SAE Standard J580 (both a and b versions) *Sealed Beam Headlam Assembly* is incorporated by reference in Tables I and III of the standard as one of the standards pertaining to headlamps for use on passenger cars, trucks, buses, and multipurpose passenger vehicles. Paragraph 5.2 of J580 states that, 'When in use, a headlamp shall not have any styling ornament or other feature, such as a glass cover or grill, in front of the lens.'; The principal referenced SAE material for motorcycle headlamps is J584 *Motorcycle Headlamps*. As options, both J584 and S4.1.1.34 of Standard No. 108 allow, in effect, a motorcycle to be equipped with one half of any sealed beam system permissible on four-wheeled motor vehicles. We therefore view the prohibition of J580 as applicable to use of any sealed beam headlamp, regardless of the type of vehicle on which it is installed.; Paragraph S4.1.3 of Standard No. 108 forbids the installation o additional equipment 'that impairs the effectiveness of lighting equipment required' by Standard No. 108. Because of moisture accumulation, discoloration, cracks, etc., a glass or plastic cover might tend over a period of time to diminish or distort the headlamp beam. This is of particular concern with reference to the unsealed headlamps implicitly permitted by SAE J584 because of the tendency of the reflector to deteriorate with age.; The agency therefore has concluded that no motorcycle headlamp may hav a glass shield in front of it when in use.; Sincerely, Frank Berndt, Chief Counsel |
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ID: aiam0941OpenMr. R. L. Coleman, Assistant Manager, Crawford and Company Insurance Adjusters, 4915 Augusta Avenue, Post Office Box 6473, Richmond, VA 23230; Mr. R. L. Coleman Assistant Manager Crawford and Company Insurance Adjusters 4915 Augusta Avenue Post Office Box 6473 Richmond VA 23230; Dear Mr. Coleman: This is in reply to your letter of September 19, 1972, concerning a accident involving a 1972 International tractor which you maintain was not certified by its manufacturer as complying with applicable Federal standards. You state that the accident may have been due to 'insufficient gross vehicle weight'.; The Certifications regulations (49 CFR Parts 567,568) do requir final-stage manufacturers to certify the conformity of vehicles they complete, by affixing to them a label containing information specified in the regulations. In the case of vehicles manufactured on or after january 1, 1972, the regulations require that such information include a gross vehicle weight rating, and a gross axle weight rating for each axle. These ratings are set by the manufacturer based on definitional criteria found in the regulations (S 568.3, 49 CFR S 571.3). Your definition of a 'final-stage' manufacturer, 'anyone who installs a component that is not readily attachable', is correct only if the component installation is to an incomplete vehicle.; Your letter has been forwarded to our Office of Standards Enforcement who will conduct whatever investigation is appropriate to determine whether violations of NHTSA regulations have occurred. Such an investigation does not include ascertaining the cause of any accident, or whether a particular vehicle may have been overloaded. It concerns only whether the respective manufacturers have complied with NHTSA regulations applicable to them. If you wish to know the results of this investigation when it is completed, you may write our Office of Standards Enforcement, NHTSA, or call Mr. George Shifflett of that office at (202) 426-1693.; Yours truly, Richard B. Dyson, Assistant Chief Counsel |
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ID: aiam1653OpenMr. H. (Speedy) Hirai, Technical Representative, Toyo Kogyo Co., Ltd. USA, 23777 Greenfield Road, Suite 462, Southfield, MI 48075; Mr. H. (Speedy) Hirai Technical Representative Toyo Kogyo Co. Ltd. USA 23777 Greenfield Road Suite 462 Southfield MI 48075; Dear Mr. Hirai: This is in response to your letter of October 18, 1974, in which yo ask whether you must supply consumer information concerning a vehicle whose motor is modified by a high-altitude kit. Further, you wish to know whether the acceleration and passing ability tests required by the regulation must be carried out at the barometric pressure required by section 575.106(d)(1)(vi).; It is our view that you must submit consumer information that meets al the requirements of Part 575, including those relating to barometric pressure, as they apply to these vehicles. Nonetheless, this does not prohibit your also including, separate from the required information, the performance characteristics of the vehicle at the altitude for which it has been modified. While we are aware that vehicles modified for high-altitude performance might not initially be sold at low altitudes, the highly mobile nature of automobile use makes it appropriate that owners be aware of their performance at the lower altitudes at which many of them will be driven and sold after their first purchase.; Yours truly, Richard B. Dyson, Acting Chief Counsel |
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ID: aiam4001OpenMr. Thomas J. Burke, Vice President - Domestic Sales, Hess & Eisenhardt Armoring Company, 8959 Blue Ash Road, Cincinnati, Ohio 45242; Mr. Thomas J. Burke Vice President - Domestic Sales Hess & Eisenhardt Armoring Company 8959 Blue Ash Road Cincinnati Ohio 45242; Dear Mr. Burke: Thank you for your letter of July 3, 1985, to Mr. Burdette and Mr Brownlee concerning a new automobile safety package your company is developing. Your letter was referred to my office for reply. You described your product as a number of modifications to a vehicle to improve its security. The modifications include changes to the windows, tires, doors, and fuel tank. I hope the following discussion explains how our regulations would affect your product.; The National Traffic and Motor Vehicle Safety Act authorizes th National Highway Traffic Safety Administration (NHTSA) to issue Federal Motor Vehicle Safety Standards for new motor vehicles and items of motor vehicle equipment. Under that authority, NHTSA has issued vehicle safety standards on a wide variety of subjects, including on tires, windows, doors and fuel tanks. I am enclosing an information sheet explaining how you can obtain copies of our standards. A manufacturer of new vehicles must certify that its vehicles conform to the requirements of all applicable safety standards. Under our certification regulating, Part 567, *Certification* (49 CFR part 567), a person who modifies a vehicle prior to its first sale to the consumer is considered an 'alterer.' Part 567.7 requires vehicle alterers to certify that the vehicle, as altered, conforms to all of our safety standards. Thus, if your company is modifying vehicles with your security package prior to their first sale to the consumer, it must certify that the vehicles, as altered, conform with all applicable standards. Any person who fails to comply with our certification regulations is subject to civil penalties under the Vehicle Safety Act.; If you company is modifying used vehicles, then its action would b affected by section 108(a)(2)(A) of the Vehicle Safety Act (15 U.S.C. S1397(a)(2)(A)), which was added to the Act in 1974 to address the problem of persons tampering with safety equipment installed on a motor vehicle. Section 108(a)(2)(A) provides, in part that:; >>>No manufacturer, distributor, dealer, or motor vehicle repai business shall 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....<<<; Thus, a manufacturer, distributor, dealer, or motor vehicle repai business making the modifications you describe must ensure that those modifications do not 'render inoperative' the compliance of the vehicle with any safety standard. The Vehicle Safety Act provides for civil penalties for persons that 'render inoperative' an element of a safety standard.; 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: aiam1203OpenMr. C.W. Todd, Market Supervisor, Fluids, Emulsions and Compounds, Dow Corning Corporation, Midland, Michigan 48640; Mr. C.W. Todd Market Supervisor Fluids Emulsions and Compounds Dow Corning Corporation Midland Michigan 48640; Dear Mr. Todd: This is in reply to your letter of July 27, 1973, asking if there is conflict between S5.4.3 of Motor Vehicle Safety Standard No. 105a and S5.2.1 of Standard No. 116.; There is no conflict. S5.4.3 of Standard No. 105a requires a label t be affixed to a new motor vehicle with the warning to use brake fluid from a sealed container. S5.2.1 of Standard No. 116 requires containers to be provided with resealable closures. A container with a resealable closure is 'sealed' within the meaning of S5.4.3 if it is resealed after initial opening.; I enclose copies of both notices as they appeared in the *Federa Register*.; Yours truly, Richard B. Dyson, Assistant Chief Counsel |
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ID: aiam2585OpenMr. E. C. Elliott, Engineer, Product Safety and Environment, Sullair Corporation, 3700 East Michigan Boulevard, Michigan City, IN 46360; Mr. E. C. Elliott Engineer Product Safety and Environment Sullair Corporation 3700 East Michigan Boulevard Michigan City IN 46360; Dear Mr. Elliott: This responds to your April 1, 1977, question whether your company' wheel mounted portable air compressors qualify as motor vehicles under the National Traffic and Motor Vehicle Safety Act, as amended, (15 U.S.C. S 1381, *et. seq*.).; The answer to your question is yes. Section 102(3) of the Act define motor vehicle as:; >>>any vehicle driven or drawn by mechanical power manufacture primarily for use on the public streets, roads, and highways, except any vehicle operated exclusively on a rail or rails.<<<; Thus, a motor vehicle is a vehicle which the manufacturer expects wil use the public highways as part of its intended function. Vehicles which use the highway on a necessary and recurring basis to move between work sites are motor vehicles. Since your portable air compressors are used in this manner they qualify as motor vehicles. For purposes of regulating motor vehicles, the National Highway Traffic Safety Administration (NHTSA) established vehicle catagories (sic) within that class. Your portable air compressors meet the definition of one of those catagories (sic), trailers.; The following safety standards are applicable to the manufacture o trailers: Safety Standard No. 108, *Lamps, Reflective Devices, and Associated Equipment*, Standard No. 121, *Air Brake Systems*, and Standard No. 106-74, *Brake Hoses* (in the case of trailers equipped with air brakes), and Standard No. 120, *Tire Selection and Rims for Vehicles Other Than Passenger Cars*.; You will have to certify the compliance of your trailers to thes safety standards. Part 566, *Manufacturer Identification* (49 CFR Part 566), specifies identification information which must be submitted to the NHTSA by manufacturers of vehicles and equipment that are regulated by our safety standards. Part 567, *Certification* (49 CFR Part 567, (sic) specifies the content and location of the certification label or tag that must be attached to motor vehicles regulated by our standards.; Sincerely, Joseph J. Levin, Jr. 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.