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: nht72-2.22OpenDATE: 02/18/72 FROM: AUTHOR UNAVAILABLE; R. B. Dyson; NHTSA TO: FMC Corporation TITLE: FMVSS INTERPRETATION TEXT: This is in reply to the questions you ask in your letter of January 7 concerning the Federal Motor Vehicle Safety Standards. In your first question you ask whether a vehicular hazard warning signal operating unit must conform to SAE Recommended Practice J910 specified in Table 1 of Standard No. 106, or to the newer SAE J910s. The answer is J910; the revision J910a cannot become a requirement of Standard No. 103 without ruleasking action by this agency. As of (Illegible Words) has issued no proposal that (Illegible Word) be adopted. You also ask whether hazard lamps at both ends of the vehicle must flash simultaneously. The operating unit is defined in (Illegible Word) as a device "which causes all turn signal lamps to flash simultaneously . . ." This means that all turn signal lamps must flash on the same cycle, and that separate cycles for froat and rear turn signal lamps are not permissible. In answer to your second question, Standard No. 108 does not yet specify requirements for side turn signal lamps, and thus does not prohibit their use on your motor home. As indicated in our "Program Plan for Motor Vehicle Safety Standards," October 1971, this agency intends to issue a notice in the near future proposing to incorporate requirements for side turn signal lamps in Standard No. 108 Finally you ask whether Standard No. 101 requires illumination (Illegible Words) handlamp switch with park ponition to operate clearance, I.D., and the marker lamps. Standard No. 101 does not require illumination of the headlamp switch, even if the switch does (Illegible Word) is the operation of other lamps whose controls, if separate, would have to be illuminated. |
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ID: 15740.ztvOpenThe Honorable Phil Gramm Dear Senator Gramm: This is in reply to your inquiry of August 3, 1997, on behalf of your constituent, Reggie Lawrence of Midland. Mr. Lawrence believes that I "hastily misinterpreted" Federal Motor Vehicle Safety Standard No. 108 in informing him by letter of May 30, 1997, that his invention would create a noncompliance with the standard. Specifically, S5.5.4 of Standard No. 108 requires that vehicle stop lamps be activated upon application of the service brakes. Mr. Lawrence's invention would result in a vehicle's stop lamps remaining activated for six seconds after the brake pedal was released. Because "there is no indication that these lamps must be deactivated when the service brakes are released," Mr. Lawrence believes that he is "well within the guidelines of the Safety Standard #108." It is quite clear to us that implicit in the requirement that stop lamps be activated upon application of the service brakes is that they be deactivated when the service brakes are not applied. Adopting Mr. Lawrence's interpretation would mean that stop lamps could remain lit indefinitely after first being activated by the application of the service brakes. This would result in a following driver having no indication at all that the vehicle ahead was braking, and detract from safety rather than adding to it. Sincerely, |
1997 |
ID: nht93-1.7OpenDATE: 01/13/93 FROM: JAMES L. VASKO TO: NHTSA TITLE: NONE ATTACHMT: ATTACHED TO LETTER DATED 2-11-93 FROM JOHN WOMACK TO JAMES L. VASKO (A40; STD. 108) TEXT: Brake lights are a very important part of the automobile. I have a Patent Pending on an invention called "FRONT BRAKE LIGHT SYSTEM". By utilizing the present turn signal lights without necessity and expense of adding new, complicated aparatus, but utilizes only the present lights and circuitry to notify the driver and or pedestrian in front of the vehicle that the vehicle is in braking mode. My 23 years experience as a Fremont Firefighter has proven over and over again, if this has been incorporated in all vehicles 30 years ago, thousands of accidents, injuries and deaths could have been prevented, not to mention, the millions of dollars Insurance Companies would have saved. I am interested in opening a dialogue with you and I will answer any questions you may have. This system will make driving safer and more predictible for every one, and we will be saving our own family and friends lives daily. The "FRONT BRAKE LIGHT SYSTEM" IS A WIN WIN SITUATION, MEANING, A WIN FOR THE CONSUMER, AUTOMAKER AND INSURANCE COMPANY. As it stands now, embodiments suggested by other patents in the field are expensive and require considerable hardware compared to my state of the art simple method. Looking forward to your response. |
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ID: 9664Open Mr. Ray Paradis Dear Mr. Paradis: We have received your letter of February 11, 1994 asking whether an intermediate side marker lamp is required on a trailer with a 24-foot bed and a 6-foot or longer tongue. S5.1.1.3 of Standard No. 108 states that intermediate side marker devices are not required "on vehicles less than 30 feet in overall length." Although the term "overall length" is not defined, we interpret it literally: the length of a vehicle as measured from one extremity to the other. For a trailer, this would include the equipment that is part of it and by which it is towed, i.e., the tongue. Therefore, intermediate lighting devices are required on the trailer configuration you describe. The fact that S5.1.1.15 refers to a trailer that is "less than 6 feet in overall length, including the trailer tongue" should not be interpreted as indicating that Standard No. 108 does not intend the tongue to be included in calculating a vehicle's "overall length" when the term appears elsewhere in the standard without reference to the tongue. Sincerely,
John Womack Acting Chief Counsel ref:108 d:3/10/94 |
1994 |
ID: nht88-4.13OpenTYPE: INTERPRETATION-NHTSA DATE: 11/23/88 FROM: ERIKA Z. JONES -- CHIEF COUNSEL, NHTSA TO: T. J. BROWN, GENERAL MANAGER, PRODUCT SERVICES, MOHAWK TIRE COMPANY TITLE: NONE ATTACHMT: LETTER DATED 10-20-87 TO ERIKA Z. JONES, NHTSA, FROM T. J. BROWN, MOHAWK TIRE COMPANY; OCC1178 TEXT: This responds to your letter requesting an opinion concerning Federal Motor Vehicle Safety Standard No. 109, New Pneumatic Tires. According to your letter, you are considering purchasing for resale a group of metric size tires from a foreign manufacture r. The maximum load and maximum pressures molded on the sidewalls of the tires are indicated in kilograms and kilopascals only, without any indication of the maximum pounds and PSI pressure. The actual stamping on the tires is as follows: Maximum Load 530kgs 165SR15 Load Range B - Maximum Pressure 230 KPA Maximum Load 600kgs 185SR14 Load Range B - Maximum Pressure 230 KPA Maximum Load 560kgs 175SR14 Load Range B - Maximum Pressure 230 KPA Maximum Load 475kgs 165SR13 Load Range B - Maximum Pressure 230 KPA Maximum Load 420kgs 155SR13 Load Range B - Maximum Pressure 220 KPA You stated that you question whether the omission of the load designation and pressure in pounds prohibits the tires from being sold in the United States and requested our opinion on the matter. As discussed below, it is our opinion that tires without t he maximum load and maximum pressures molded on the sidewalls in English units do not meet the requirements of Standard No. 109 and therefore cannot be imported into the United States for use on passenger cars. By way of background information, the National Highway Traffic Safety Administration (NHTSA) does not provide approvals of motor vehicles or motor vehicle equipment Under the National Traffic and Motor Vehicle Safety Act, it is the responsibility of the manufacturer to ensure that its motor vehicles or equipment meet applicable requirements. The following represents our opinion based on the facts provided in your letter. All tires imported into the United States for use on passenger cars must be certified as complying with Federal Motor Vehicle Safety Standard No. 109. The standard specifies performance requirements (strength, endurance, high speed, and resistance to be ad unseating), marking requirements (treadwear indicators and labeling information), and tire
and rim matching information requirements which must be satisfied by each tire sold in the United States. Section S4.2.1(b) of Standard No. 109 requires that the maximum permissible inflation pressure of each tire "shall be either 32, 36, 40 or 60 psi, or 240, 280, 300 or 340 kPa." Thus, no value other than those listed may be used for the maximum permissibl e inflation pressure of a passenger car tire. Sections S4.3(b) and (c) of the standard specify that each tire shall have permanently molded onto the sidewalls the maximum permissible inflation pressure and the maximum load rating for the tire. Section S4.2.1(b) originally listed only three permissible maximum inflation pressures, all in English units (32, 36 and 40 psi). The agency interpreted sections S4.3(b) and (c) to require that the maximum permissible inflation pressure and maximum load rating be in English units, since this is the system of measurement which will be used and understood by most consumers. The first permissible metric maximum inflation pressures, 240 and 280 kPa, were added to Standard No. 109 in 1977. 42 FR 12869, March 7, 1977. In permitting metric-series tires, the agency established a requirement that the metric unit inflation pressu re and load rating be supplemented by English system equivalents on the tire sidewall. That requirement, set forth in section S4.3.4, now reads as follows: S4.3.4 If the maximum inflation pressure of a tire is 240, 280, 300 or 340 kPa, then: (a) Each marking of that inflation pressure pursuant to S4.3(b) shall be followed in parenthesis by the equivalent inflation pressure in psi, rounded to the next whole number; and (b) Each marking of the tire's maximum load rating pursuant to S4.3(b) shall be followed in parenthesis by the equivalent load rating in pounds, rounded to the nearest whole number. Thus, each tire must have a maximum inflation pressure of either 32 psi, 36 psi, 40 psi, 60 psi, 240 kPa, 280 kPa, 300 or 340 kPa. If the maximum inflation pressure is 32 psi, 36 psi, 40 psi, or 60 psi, the maximum permissible inflation pressure and max imum load rating provided pursuant to sections S4.3(b) and (c) must be in English units. I would note that so long as the information appears in English units, there is no reason that it cannot also be expressed in equivalent metric units, if the presen tation of the additional information does not cause confusion about the required information. If the maximum permissible inflation pressure is 240 kPa, 280 kPa, 300 or 340 kPa, the maximum permissible inflation pressure in kPa provided pursuant to secti on S4.3(b) must be followed in parenthesis by the equivalent inflation pressure in psi, rounded to the next higher whole number, and the maximum load rating provided pursuant to section S4.3(c) in kilograms must be followed in parenthesis by the equivale nt load rating in pounds, rounded to the nearest whole number.
Since the tires you are considering purchasing do not have the maximum load and maximum pressures molded on the sidewalls in English units, they do not meet the requirements of Standard No. 109 and may not be imported into the United States for use on pa ssenger cars. I have also enclosed for your information a copy of a December 12, 1985, letter, addressed to Mutual Trading Corporation, which provides a general discussion of issues related to the importation and sale of tires in the United States. Enclosures |
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ID: 3237oOpen Mr. T. J. Brown Dear Mr. Brown: This responds to your letter requesting an opinion concerning Federal Motor Vehicle Safety Standard No. l09, New Pneumatic Tires. According to your letter, you are considering purchasing for resale a group of metric size tires from a foreign manufacturer. The maximum load and maximum pressures molded on the sidewalls of the tires are indicated in kilograms and kilopascals only, without any indication of the maximum pounds and PSI pressure. The actual stamping on the tires is as follows: l65SRl5 Load Range B Maximum Load 530kgs - Maximum Pressure 230 KPA l85SRl4 Load Range B Maximum Load 600kgs - Maximum Pressure 230 KPA l75SRl4 Load Range B Maximum Load 560kgs - Maximum Pressure 230 KPA l65SRl3 Load Range B Maximum Load 475kgs - Maximum Pressure 230 KPA l55SRl3 Load Range B Maximum Load 420kgs - Maximum Pressure 220 KPA You stated that you question whether the omission of the load designation and pressure in pounds prohibits the tires from being sold in the United States and requested our opinion on the matter. As discussed below, it is our opinion that tires without the maximum load and maximum pressures molded on the sidewalls in English units do not meet the requirements of Standard No. l09 and therefore cannot be imported into the United States for use on passenger cars. By way of background information, the National Highway Traffic Safety Administration (NHTSA) does not provide approvals of motor vehicles or motor vehicle equipment. Under the National Traffic and Motor Vehicle Safety Act, it is the responsibility of the manufacturer to ensure that its motor vehicles or equipment meet applicable requirements. The following represents our opinion based on the facts provided in your letter. All tires imported into the United States for use on passenger cars must be certified as complying with Federal Motor Vehicle Safety Standard No. l09. The standard specifies performance requirements (strength, endurance, high speed, and resistance to bead unseating), marking requirements (treadwear indicators and labeling information), and tire and rim matching information requirements which must be satisfied by each tire sold in the United States. Section S4.2.l(b) of Standard No. l09 requires that the maximum permissible inflation pressure of each tire "shall be either 32, 36, 40 or 60 psi, or 240, 280, 300 or 340 kPa." Thus, no value other than those listed may be used for the maximum permissible inflation pressure of a passenger car tire. Sections S4.3(b) and (c) of the standard specify that each tire shall have permanently molded onto the sidewalls the maximum permissible inflation pressure and the maximum load rating for the tire. Section S4.2.l(b) originally listed only three permissible maximum inflation pressures, all in English units (32, 36 and 40 psi). The agency interpreted sections S4.3(b) and (c) to require that the maximum permissible inflation pressure and maximum load rating be in English units, since this is the system of measurement which will be used and understood by most consumers. The first permissible metric maximum inflation pressures, 240 and 280 kPa, were added to Standard No. l09 in l977. 42 FR 12869, March 7, l977. In permitting metric-series tires, the agency established a requirement that the metric unit inflation pressure and load rating be supplemented by English system equivalents on the tire sidewall. That requirement, set forth in section S4.3.4, now reads as follows: S4.3.4 If the maximum inflation pressure of a tire is 240, 280, 300 or 340 kPa, then: (a) Each marking of that inflation pressure pursuant to S4.3(b) shall be followed in parenthesis by the equivalent inflation pressure in psi, rounded to the next whole number; and (b) Each marking of the tire's maximum load rating pursuant to S4.3(b) shall be followed in parenthesis by the equivalent load rating in pounds, rounded to the nearest whole number. Thus, each tire must have a maximum inflation pressure of either 32 psi, 36 psi, 40 psi, 60 psi, 240 kPa, 280 kPa, 300 or 340 kPa. If the maximum inflation pressure is 32 psi, 36 psi, 40 psi, or 60 psi, the maximum permissible inflation pressure and maximum load rating provided pursuant to sections S4.3(b) and (c) must be in English units. I would note that so long as the information appears in English units, there is no reason that it cannot also be expressed in equivalent metric units, if the presentation of the additional information does not cause confusion about the required information. If the maximum permissible inflation pressure is 240 kPa, 280 kPa, 300 or 340 kPa, the maximum permissible inflation pressure in kPa provided pursuant to section S4.3(b) must be followed in parenthesis by the equivalent inflation pressure in psi, rounded to the next higher whole number, and the maximum load rating provided pursuant to section S4.3(c) in kilograms must be followed in parenthesis by the equivalent load rating in pounds, rounded to the nearest whole number. Since the tires you are considering purchasing do not have the maximum load and maximum pressures molded on the sidewalls in English units, they do not meet the requirements of Standard No. l09 and may not be imported into the United States for use on passenger cars. I have also enclosed for your information a copy of a December l2, l985, letter, addressed to Mutual Trading Corporation, which provides a general discussion of issues related to the importation and sale of tires in the United Sates. Sincerely,
Erika Z. Jones Chief Counsel Enclosures /ref:109 d:ll/23/88 |
1970 |
ID: nokiantyres(4-7-05)OpenLaDonna Bowers
This is in reply to your E-mail letter of March 10, 2005, to Andrew DiMarsico of my staff requesting a clarification of the reporting of tires involved in a foreign recall. You present the following hypothetical to illustrate your concerns:
You ask whether there is a need to report a recall of these tires which have not been sent to, or purchased in, the USA, but will likely be sent to, and sold in, the USA in the future in limited quantities and from subsequent production weeks? The answer is no. The National Highway Traffic Safety Administrations (NHTSA) regulations concerning foreign defect reporting are located at 49 C.F.R. Part 579, Subpart B. Section 579.11 requires manufacturers to report to NHTSA within five days of determining to conduct a safety recall or other safety campaign in a foreign country covering a motor vehicle, item of motor vehicle equipment, or tire that is identical or substantially similar to a vehicle, item of equipment, or tire sold or offered for sale in the United States. With respect to the facts presented in your hypothetical, the tires have not been shipped to or offered for sale in the United States. Therefore, the manufacturer of the tire in your hypothetical would not have to report the recall determination to NHTSA at this time. If you have any questions, you may phone Andrew DiMarsico of my staff at (202) 366-5263. Sincerely, Jacqueline Glassman ref:579 |
2005 |
ID: nht90-2.81OpenTYPE: Interpretation-NHTSA DATE: June 11, 1990 FROM: Ron Marion -- Sales Engineer, Thomas Built Buses, Inc. TO: Paul Jackson Rice -- Chief Counsel, U.S. Dept. of Transportation TITLE: None ATTACHMT: Attached to letter dated 11-11-77 from James Tydings to Roger Tilton; Also attached to letter dated 12-21-77 from Joseph J. Levin, Jr. to James Tydings; Also attached to letter dated 3-8-91 from Paul Jackson Rice to Ron Marion (A37; VSA 102(14) Part 571.3); Also attached to letter dated 5-10-82 from Frank Berndt (Signature by Stephen P. Wood) to Martin V. Chauvin; Also attached to letter dated 5-12-81 from Frank Berndt to Doris Perlmutter TEXT: This letter is in reference to a recent telephone conversation between Mr. Morris Adams of Thomas Built Buses and Ms. Dee Fujita of your office. We at Thomas Built Buses would like to request a ruling on an issue which continues to surface in the school bus industry. With an increasing number of families in which both parents work full-time jobs, more and more children are being placed in privately owned and operated pre-primary school type facilities. As referenced in the attached letter, the NHTSA has determined that buses purchased to transport pre-primary Headstart children to and from school and related events should be "School Buses" (within the scope of the bus definition . . . designed for carr ying more than 10 persons). My question is, does this same ruling also apply to the privately owned and operated pre-primary facilities? Thank you for your assistance in this matter. |
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ID: 77-3.24OpenTYPE: INTERPRETATION-NHTSA DATE: 07/13/77 FROM: AUTHOR UNAVAILABLE; Brock Adams; NHTSA TO: Hon. R. J. Lagomarsino - H.O.R. TITLE: FMVSS INTERPRETATION TEXT: This responds to your May 16, 1977, letter enclosing correspondence from Mr. (Illegible Word) Smith concerning the safety of radial tires. The National Highway Traffic Safety Administration (NHTSA), an agency of the Department of Transportation, promulgates safety standards requiring that tires meet minimum levels of strength and endurance. Should a tire not meet the performance levels prescribed in the tire standards, its manufacturer would be in violation of the National Traffic and Motor Vehicle Safety Act (Pub. (Illegible Word) 89-563) and subject to the penalties specified thereunder. The NHTSA has not concluded that radial tires produced in the United States are less safe than those produced elsewhere. All tires, sold in the United States, both domestically and foreign-manufactured, must comply with (Illegible Word) safety standards. The problem to which your constituent refers, the so-called "phoney steel belted radial," concerns steel belted radial ply tires that use only a single steel belt in their construction. As cited above, our standards specify performance and not design requirements. Thus, tire manufacturers may use whatever materials they choose in constructing tires that meet the prescribed performance level. Within our standard No. 109, New Pneumatic Tires - Passenger Cars, we require the tire manufacturer to identify the generic name of the material used in the ply cords, and we require that the actual number of plies in the tread area be specified. Therefore, when a consumer purchases a new passenger car tire, he can identify whether the steel belted radial ply tire has one or two steel belts. Since your constituent describes a situation of misleading advertising, I believe his letter should also be reviewed by the Federal Trade Commission. I suggest that you contact that agency for an opinion on the issue. |
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ID: nht68-1.45OpenDATE: 01/18/68 FROM: AUTHOR UNAVAILABLE; Joseph R. O'Gorman; NHTSA TO: Ander-BTT Incorporated TITLE: FMVSR INTERPRETATION TEXT: We are in receipt of your letter dated November 30, 1967, forwarded to us through the Michigan Department of State Police. This letter is in answer to your inquiry as to whether your mobile home or trailer house is required to comply with the Federal Motor Vehicle Safety Standards. From the brief description of your product we would state that your vehicle would fall into the category of the multi-purpose passenger vehicle. Enclosed is a copy of the Initial Federal Motor Vehicle Safety Standards. Your attention is directed to Subpart B. This section indicates those safety standards which multi-purpose passenger vehicles are required to comply with. Also enclosed is a notice published in the Federal Register dated November 4, 1967, stating the Certification Requirement effective January 1, 1968. If we can provide additional information, please feel free to contact this office. |
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.