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: aiam1309OpenMr. Ralph J. Kalberlon, Executive Vice President, Missouri Automobile Dealers Assoc., 205 East Capitol Avenue, Jefferson City, MO 65101; Mr. Ralph J. Kalberlon Executive Vice President Missouri Automobile Dealers Assoc. 205 East Capitol Avenue Jefferson City MO 65101; Dear Mr. Kalberlon: This is in reply to your letter of October 10, 1973, concerning th legality of disconnecting seat belt interlocks.; The interlock is a required item of safety equipment that must b operable on any new car when it is sold or offered for sale, pursuant to section 108(a)(1) of the National Traffic and Motor Vehicle Safety Act. After an interlock equipped car is sold, however, the purchaser may disconnect the interlock, without violating the Act, by virtue of section 108(b)(1), which exempts transactions after the first purchase of the vehicle.; If a dealer offers to disconnect an interlock as an inducement to th sale of the vehicle, it is our opinion that a violation of the act occurs even though the actual disconnection may take place after delivery of the vehicle. If, on the other hand, the subject of the interlock is not discussed during the sale and the buyer subsequently requests disconnection on the basis of his experience with the vehicle, the dealer would not violate the Act if he disconnected the interlock.; Although a dealer does not violate the act by suggesting that the buye go somewhere else to have the interlock disconnected, I am sure you appreciate the troublesome consequences such advice may bring for the buyer if the resulting disconnection is carelessly performed.; Yours truly, Richard B. Dyson, Assistant Chief Counsel |
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ID: aiam3334OpenMr. R. H. Snyder, Vice President, Tire Technology, Uniroyal Tire Company, 6600 East Jefferson Avenue, Detroit, MI 48232; Mr. R. H. Snyder Vice President Tire Technology Uniroyal Tire Company 6600 East Jefferson Avenue Detroit MI 48232; Dear Mr. Synder: This is in response to your letter of August 14, 1980, requestin interpretation of the Uniform Tire Quality Grading (UTQG) Standards (49 CFR S 575.104) with regard to the assignment of treadwear grades. You report that Uniroyal has encountered variations in treadwear test data derived from UTQG tests conducted by different testing organizations. You ask whether a tire manufacturer is obligated under the UTQG treadwear grading procedure to base its grades on those test results which produce the lowest treadwear grade, or may use any available test data as the basis for grade assignment.; Uniform Tire Quality Grading, as with other National Highway Traffi Safety Administration (NHTSA) regulations, involves a self-certification process in which manufacturers bear the primary responsibility for assuring that their products conform to required levels of performance, in this case the levels represented by their assigned grades. NHTSA's Office of Vehicle Safety Compliance (OVSC) conducts testing to verify that various tires actually provide levels of performance consistent with their grades. When OVSC testing produces results at variance with assigned grades, the manufacturer involved is given an opportunity to provide justification for its grade assignments.; In determining that a product achieves a particular level o performance under the UTQG procedures, a manufacturer may exercise a considerable degree of discretion as to the amount of testing necessary to assure that its conclusions regarding compliance will withstand NHTSA scrutiny. In evaluating the performance of a product, NHTSA does not require that a manufacturer base its judgment on any particular piece of test data or on all available data. In fact, a manufacturer may disregard data from a particular source entirely, if the manufacturer can establish that other data provides a reasonable basis for grading.; However, a manufacturer cannot establish compliance by arbitraril picking and choosing among available data to select results of that test which happened to produce the most favorable result. Data used to establish compliance must be reliable and consistently reproducible, and cannot have been derived through manipulative devices, e.g., abusive driving, or unexacting test procedures. It is the responsibility of the manufacturer to base its conclusions on data demonstrably developed in full conformance with the requirements of the regulation.; NHTSA will provide confidential treatment for your letter of August 14 1980, and the accompanying data.; Sincerely, Frank Berndt, Chief Counsel |
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ID: aiam2876OpenMr. Ken Yoneyama, Chief Engineer, Bridgestone Research Inc., 350 Fifth Ave., Suite 4202, New York, NY 10001; Mr. Ken Yoneyama Chief Engineer Bridgestone Research Inc. 350 Fifth Ave. Suite 4202 New York NY 10001; Dear Mr. Yoneyama: This is in response to your letter of September 22, 1978, askin whether tires listed in Table 1-A of Appendix A, Federal Motor Vehicle Safety Standard No. 109, *New Pneumatic Tires - Passenger Cars*, must comply with Part 575.104, *Uniform Tire Quality Grading Standards*, (UTQGS), if the tires are installed as original equipment on multi-purpose passenger vehicles. You also inquire as to the effective dates for the provision of UTQGS information to first purchasers of new motor vehicles under Part 575.104(d)(1)(iii).; UTQGS applies to a tire type whose predominant contemplated use is o passenger cars, even if the manufacturer knows the tire type is also used as original equipment on multi-purpose passenger vehicles. A manufacturer's determination to certify a tire as conforming to Standard No. 109, will also determine the tire's classification for purposes of UTQGS. Thus, UTQGS would apply to any tire labeled with a size designation listed in Appendix A of Standard No. 109, other than a deep tread, winter-type snow tire or space- saver or temporary use spare tire, regardless of the tire's actual use.; On October 23, 1978, NHTSA issued a *Federal Register* notice (cop enclosed) granting the petition of American Motors corporation to revise the effective dates for Part 575.104(d)(1)(iii) to September 1, 1979 for bias-ply tires and March 1, 1980 for bias-belted tires. On the basis of this change, your statement regarding effective dates is correct.; Sincerely, Joseph J. Levin, Jr., Chief Counsel |
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ID: aiam1759OpenMr. Hans von Payr, General Manager, VDO Instruments, 116 Victor Avenue, Detroit, Michigan 48203; Mr. Hans von Payr General Manager VDO Instruments 116 Victor Avenue Detroit Michigan 48203; Dear Mr. von Payr: This is in reply to your letter of December 26, 1974 asking question about Motor Vehicle Safety Standard No. 123, *Motorcycle Controls and Displays*.; Standard No. 123 applies to motorcycles, and the manufacturer of th completed vehicle is responsible for compliance with the standard. The standard does not include items manufactured for the aftermarket. Under an amendment to the National Traffic and Motor Vehicle Safety Act of 1966 that became effective late in December 1974 a dealer may not 'render inoperative', *e.g.* remove, equipment installed by the manufacturer that has been installed in compliance with a standard. There would be no objection, however, if a dealer removed an originally installed speedometer and replaced it with one that also met the Federal requirements.; The date of applicability of a standard is the date the vehicle wa manufactured, not the date it is sold. Therefore non-complying motorcycles manufactured before the effective date of Standard No. 123 - September 1, 1974 - may be sold after that date. The standard applies to those motorcycles manufactured primarily for use on the public roads, and not to mini-bikes, trail bikes, ATVs, or other non-licensed vehicles intended for off-road use.; Standard No. 123 does not require a specific size for numerals, onl that 'Major graduations and numerals appear at 10 mph intervals, minor graduations of the 5 mph intervals' (Column 3, Table 3). With respect to your paragraphs a) and b) on page 3 of your letter, elimination of any speed indication at the required 10 mph intervals would result in a noncompliance of the cycle on which the speedometer was mounted. Since your enduro and chopper speedometers are marked only at 20 mph intervals they do not meet the requirements of Standard No. 123 for original motorcycle equipment.; Yours truly, Richard B. Dyson, Acting Chief Counsel |
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ID: aiam3764OpenJohn Bertman, Esq., Bertman, Johnson and Sahli, 401 Twelfth Street (Route #54), P.O. Box 440, Hammonton, NJ 08037-0440; John Bertman Esq. Bertman Johnson and Sahli 401 Twelfth Street (Route #54) P.O. Box 440 Hammonton NJ 08037-0440; Dear Mr. Bertman: This responds to your recent letter to this office, seeking informatio on retreaded passenger car tires. You asked for the name of the retreader of a tire with the code letters 'BJE' marked on the sidewall. That retreader is Trio Tire Service, Inc. of Clementon, New Jersey. You also asked if there were any regulations applicable to the retread of radial tires. All retreaded passenger car tires (whether bias or radial) must be certified by the retreader as complying with the requirements of Federal Motor Vehicle Safety Standard No. 117 (49 CFR S 571.117). I have enclosed a copy of the standard for your information.; Should you have any further questions or need further information i this area, please contact Mr. Stephen Kratzke of my staff at this address and at (202) 426- 2992.; Sincerely, Frank Berndt, Chief Counsel |
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ID: aiam1036OpenMr. Sanford Davis, Corporate Flammability Coordinator, BASF Wyandotte Corporation, Wyandotte, MI, 48192; Mr. Sanford Davis Corporate Flammability Coordinator BASF Wyandotte Corporation Wyandotte MI 48192; Dear Mr. Davis: This is in reply to your letter of February 20, 1973, asking for a interpretation of the self-extinguishing test in the burn- rate requirement of Paragraph S4.3 of Motor Vehicle Safety Standard No. 302, 'Flammability of Interior Materials'. You ask whether both the 60- second as well as the 2-inch criterion must be satisfied in order to meet this self-extinguishing test. The answer to your question is yes. Both criteria must be met before any material shall be considered to have satisfied the burn-rate requirement.; Yours truly, Richard B. Dyson, Assistant Chief Counsel |
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ID: aiam4234OpenDennis H. Oyakawa, Esq., Graham & James, 725 South Figueroa Street, Los Angeles, CA 90017-5434; Dennis H. Oyakawa Esq. Graham & James 725 South Figueroa Street Los Angeles CA 90017-5434; Dear Mr. Oyakawa: Thank you for your letter of September 16, 1986, to Stephen Oesch of m staff concerning how the National Traffic and Motor Vehicle Safety Act and our regulations affect the proposed manufacture and sale of aftermarket safety belts by your client. As discussed below, your proposed plan would not violate either the Vehicle Safety Act or our regulations.; You explained that your client has supplied safety belts to a vehicl manufacturer for use both as an item of original equipment in a new vehicle and as item of replacement equipment for sale in the aftermarket. You said your client has recently been requested by the vehicle manufacturer to supply safety belts to be used as a replacement part for an older model vehicle which was exported to and marketed in the United States over 10 years age. You further explained that your client manufactured the original safety belts used in this older model vehicle, but is no longer equipped to readily manufacture the original safety belts.; Your client wishes to supply the vehicle manufacturer with a newe model safety belt. This newer safety belt has been designed to be installed as a replacement part in the older model vehicle and will fully comply with all of the requirements of Standard No. 209, *Seat Belt Assemblies*. In addition, the safety belt is also designed so that when it is installed in a vehicle, the vehicle will continue to comply with all of the applicable requirements of Standard Nos. 208, *Occupant Crash Protection*, and 210, *Seat Belt Assembly Anchorages*. Finally, you said that the newer model safety belt will not render inoperative any other features of the vehicle necessary to meet any other applicable safety standards.; As you are already aware, your client's proposed safety belt would b required to comply with Standard No. 209. As you are also aware, installation of your client's safety belt by a manufacturer, distributor, dealer, or motor vehicle repair shop would be affected by the render inoperative provision of section 108(a)(2)(A) of the Vehicle Safety Act. However, as stated in your letter, your client has determined that installation of the belt will not render inoperative any other safety features of the vehicle. There is another 108(a)(2)(A) related issue raised by your letter. This concerns whether an item of equipment installed in accordance with one version of a Federal motor vehicle safety standard can be replaced with an item of equipment that complies with a later version of that standard. The agency addressed this issue in a letter of July 7, 1975 to Toyo Kogyo Co., Ltd. In that letter, the agency explained that it would not be a violation of section 108 as long as the vehicle or equipment complies with the safety standards in effect at the time of its manufacture or with the standards in effect at the time a particular system is replaced or altered, even if the new standards set less stringent performance requirements.; If you have any further questions, please let me know. Sincerely, Erika Z. Jones, Chief Counsel |
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ID: aiam1466OpenMr. Earl V. Gordon, Manager of Engineering, The Adams & Westlake Company, 1025 North Michigan Street, Elkhart, IN 46514; Mr. Earl V. Gordon Manager of Engineering The Adams & Westlake Company 1025 North Michigan Street Elkhart IN 46514; Dear Mr. Gordon: This is in reply to your letter of March 13, 1974, asking whethe S5.3.2. of Motor Vehicle Safety Standard No. 217, Bus Window Retention and Release,' permits the use of more than one release mechanism on any one opening if each mechanism requires a separate motion to release.; Standard No. 217 does not prohibit the use of more than one separat release mechanism for a single opening. However, S5.3.2 does limit to two the number of total force applications, and this limits the number of separate release mechanisms to two. If two release mechanisms are used, each must be operated by only one force application, and one of these force applications must differ by 90 degrees to 180 degrees from the direction of the initial push-out motion of the emergency exit.; Of course, in using this configuration, the other requirement pertaining to emergency exits and release mechanisms in Standard No. 217 must also be met.; Yours truly, Richard B. Dyson, Assistant Chief Counsel |
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ID: aiam4664OpenMr. Stephen R. Darling Presvac Systems (Burlington) Ltd. 4131 Morris Drive Burlington, Ontario, Canada L7L 5L5; Mr. Stephen R. Darling Presvac Systems (Burlington) Ltd. 4131 Morris Drive Burlington Ontario Canada L7L 5L5; "Dear Mr. Darling: This responds to your inquiry about an amendment t 49 CFR Part 575, Consumer Information Regulations, requiring vehicle manufacturers to include information in the owner's manual (or on a one-page document if there is no owner's manual) about the National Highway Traffic Safety Administration's Auto Safety Hotline and its defect investigation and remedy and recall authority. (54 FR 48745, November 27, 1989, copy enclosed). I apologize for the delay in our response. You explained that you are involved in three types of activities: the manufacture of liquid cargo vessel trailers, the fabrication of liquid cargo tanks, and the installation of these tanks onto existing or modified truck chassis. While you acknowledged your obligation to furnish the consumer information for the trailers you manufacture, you were uncertain about your responsibilities to furnish this information for the liquid cargo tanks you fabricate and install. You asked whether you are required to supply the specified consumer information in these instances. Your questions are responded to below. Section 575.6(a)(2)(i), as amended, provides that 'At the time a motor vehicle manufactured on or after September 1, 1990 is delivered to the first purchaser for purposes other than resale, the manufacturer shall provide to the purchaser' a specified statement about this agency's activities related to motor vehicle defects. Among other things, the specified statement indicates that if an owner believes the vehicle has a defect which could cause a crash or an injury or death, the owner should inform NHTSA in addition to notifying the manufacturer. The manufacturer's name must be indicated in the statement. In responding to your questions, I note that section 575.6(a)(2)(i) applies to manufacturers of new motor vehicles. As a manufacturer of trailers, you are, of course, responsible for providing the specified consumer information to the first purchaser of such trailers (for purposes other than resale). On the other hand, in situations where you are not a vehicle manufacturer, e.g., where you may be installing tanks on used motor vehicles, the requirements would not apply. Your letter also raises the issue of how section 575.6(a)(2)(i) applies in situations where there is more than one manufacturer of a motor vehicle, i.e., where vehicles are manufactured in two or more stages. While it is not clear from your letter, it is possible that you may be a final stage manufacturer under 49 CFR Part 568. (The term 'final stage manufacturer' is defined in 49 CFR Part 568.3.) As indicated above, section 575.6(a)(2)(i) specifies that, at the time a vehicle is delivered to the first purchaser for purposes other than resale, 'the manufacturer' must provide specified consumer information to the purchaser. Since the regulation requires information to be provided at the time of first consumer sale, we construe it to require the manufacturer of the completed vehicle, i.e., the final stage manufacturer, to meet this requirement. As a general rule, the final stage manufacturer is the manufacturer that has the closest relationship to the dealer which sells the vehicle to the consumer. It is also the manufacturer that the consumer will typically contact first in the event of problems. I hope this information is helpful. If you have any further questions, 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 Enclosures"; |
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ID: aiam1935OpenMr. Ernest D. Mathews, Chief, Field Services, Department of Motor Vehicles, Sate of Vermont, Montpelier, VT 05602; Mr. Ernest D. Mathews Chief Field Services Department of Motor Vehicles Sate of Vermont Montpelier VT 05602; Dear Mr. Mathews: This is in reply to your letter of April 17, 1975, to this agenc asking questions about paragraph S4.6(b) of Motor Vehicle Safety Standard No. 108, relating to headlamp flashers. Your reference to S4.5.8(b) is out-dated by approximately three years and I am enclosing a copy of Standard No. 108 as it now exists.; You asked the reason for the section in question, which provides tha 'All other lamps shall be steady- burning, except that means may be provided to flash headlamps and side marker lamps for signaling purposes.' You also asked whether all motor vehicles, including motorcycles, are 'authorized' by this section to use flashing headlamps, and finally whether the standard prohibits States from promulgating regulations to control flashing headlamps.; S4.6(b) was not intended as a regulation of this aspect of moto vehicle performance, in the sense that it would preempt all State regulation of the sale or use of headlamp flashers. It is basically merely an exception to the requirement of Standard 108 that all lamps (other than turn signals, hazard warning signals, and school bus warning signals) be steady-burning. The section, in other words, was included to make it clear that automatic headlamp flashers are not prohibited by the Federal standard. With reference to your questions, this is the only way in which they are 'authorized' by Standard 108.; We have concluded, therefore, that State regulation of headlam flashers is not preempted by the Federal standard.; Sincerely, James C. Schultz, 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.