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: aiam4919OpenMr. Gene Byrd Legris Incorporated 244 Paul Rd. Rochester, N.Y. 14624; Mr. Gene Byrd Legris Incorporated 244 Paul Rd. Rochester N.Y. 14624; Dear Mr. Byrd: This responds to your September 23, 1991 letter askin about the air pressure requirement specified in S7.3.8 of Standard 106, Brake Hoses. Your letter has been referred to my office for reply. Paragraph S7.3.8 states that an air brake hose assembly shall contain air pressure of 200 psi for 5 minutes without loss of more than 5 psi. You ask whether Standard 106 specifies the length of the hose for an assembly tested to S7.3.8. The answer is no, the standard does not have a generic specification for hose length. Instead, each brake hose assembly is required to meet this requirement as manufactured and sold. For purposes of compliance testing, NHTSA obtains a brake hose assembly specimen by purchasing it on the market or directly from the manufacturer. The length of the hose might vary from assembly to assembly, depending on the particular configuration of an assembly. The assembly is tested as sold to obtain performance results that indicate the assembly's real world performance. While S7.3.8 is a performance requirement for assemblies, we understand that your company (an end fitting manufacturer) seeks to ensure that an assembly made with your fitting will not fail to meet S7.3.8 due to the fitting. Since an assembly is tested to S7.3.8 in the configuration in which it is sold, you could test to the requirement using the length of hose that will be used with your fitting. Legris might be able to avoid duplicative tests by conducting 'worst case' testing, such as tests using a fitting with a hose of a length most likely to exhibit an excessive loss of air pressure. Please contact us if you have further questions. Sincerely, Paul Jackson Rice Chief Counsel; |
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ID: aiam3031OpenMr. Moe Pare, Jr., Director of Design, Cars & Concepts, Inc., 12500 E. Grand River, Brighton, MI 48116; Mr. Moe Pare Jr. Director of Design Cars & Concepts Inc. 12500 E. Grand River Brighton MI 48116; Dear Mr. Pare: This responds to your May 21, 1979, letter concerning the markin requirements for vehicle windshields having shade bands. You asked whether the 'A S1' marking symbol required by Safety Standard No. 205, *Glazing Materials*, can be placed on the tint band itself rather than on the glazing material below the band, if the tint band is a flexible sheet applied on top of the glazing.; Safety Standard No. 205 incorporates by reference the American Nationa Standard 'Safety Code for Safety Glazing Materials', ANS Z26. The ANS Z26 standard requires special additional markings for glazing that has shade bands or tinted areas:; >>>'Glazing materials, which in a single sheet of material, ar intentionally made with an area having a luminous transmittance of not less than 70 percent (Test NO. 2), adjoining an area which has less than 70-percent luminous transmittance, shall be permanently marked at the edge of the sheet to show the limits of the area which is intended to comply with Test No. 2. The markings shall be A S1 or A S2, etc., the direction of the arrow indicating the portion of the material which complies with Test No. 2 and the number indicating the item with which that portion of the sheet complies ....'<<<; You will note from the quoted portion of this specification that th special marking is only required if the tinted shade band area of the windshield has a luminous transmittance of less than 70 percent. Your letter states that the transparent windshield tint band that you intend to use allows 70 percent light transmission. Therefore, you would not be required to use the 'A S1' special marking either on the band itself or on the glazing.; For removable tint bands of this type that do not have a 70 percen light transmission, however, the agency would permit the 'A S1' marking to be on the tint band itself rather than on the underlying glazing, provided the marking is located at the lowest possible portion of the tint band.; Sincerely, Frank Berndt, Chief Counsel |
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ID: aiam3977OpenMr. V. Stuart James, Executive Vice President, X-Ten Corporation, 855 Sansome Street, San Franciso(sic), California 94111; Mr. V. Stuart James Executive Vice President X-Ten Corporation 855 Sansome Street San Franciso(sic) California 94111; Dear Mr. James: this responds to your letter to Mr. Kratzke of my staff, asking for a interpretation of the requirements of Standard No. 121, *Air Brake Systems* (49 CFR S571.121). Specifically, you asked if the timing requirements of S5.3.3 and S5.3.4 must be satisfied by trailers which are 'heavy hauler trailers' within the meaning of S4. As Mr. Kratzke told you in a telephone conversation, heavy hauler trailers are exempted from all the requirements of S5.3, including the timing requirements.; You stated that your company is manufacturing extendable containe chassis trailers. The brake lines in those vehicles are designed to extend with the vehicle frame. S4 of Standard No. 121 defines, in part, a heavy hauler trailer as a trailer whose 'brake lines are designed to adapt to separation or extension of the vehicle frame...' Thus, your trailer would be considered a heavy hauler trailer for the purpose of Standard No. 121.; Section S5.3 sets forth road test requirements, compliance with whic must be certified for all trucks, buses and trailers. Generally, all trailers are required to be certified as complying with the timing requirements of S5.3.3 and S5.3.4. This general rule is limited by the last sentence of the S5.3, which specifies, 'However, *a heavy hauler trailer* and the truck and trailer portions of an auto transporter *need not meet the requirements of S5.3*' [Emphasis added] Thus, heavy hauler trailers are expressly exempted from all the requirements of S5.3, including the timing requirements.; If you have any further questions, please let me know. Sincerely, Jeffrey R. Miller, Chief Counsel |
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ID: aiam1756OpenMr. Michael Schenker,President,Coilhose Pneumatics,415 Hope Avenue,Rosell, New Jersey 07203; Mr. Michael Schenker President Coilhose Pneumatics 415 Hope Avenue Rosell New Jersey 07203; Dear Mr. Schenker:#Please forgive the delay in responding to you letter of November 15, 1974. I have enclosed a copy of Federal Motor Vehicle Safety Standard No. 106-74, *Brake Hoses*, a copy of the most recent amendment to the standard (39 FR 39725), and an information sheet entitled 'Where to Obtain Motor Vehicle Safety Standards and Regulations'. #The system of staggered effective dates is as follows: All brake hose and brake hose end fittings manufactured after September 1, 1974, must conform to the standard. All brake hose assemblies manufactured after March 1, 1975, must conform to the standard. All vehicles manufactured after September 1, 1975, must contain only hose and assemblies which conform to the standard.#As a manufacturer of air brake hose assemblies, you must label each assembly manufacturer on or after March 1, 1975, with a band as described in S7.2 and S5.2.4. Use of the band before March 1, 1975, is not permitted. Assemblies manufactured after this date must consist of hose and end fittings which also conform to the standard. During the period from March 1, 1975 to August 31, 1975, however, S12 (added by the recent amendment) permits the construction of assemblies with hoes and end fittings which are not labeled according to the standard, as long as they meet all the performance requirements. These assemblies must nevertheless be labeled with a band.#Please note also that assemblies manufactured before March 1, 1975, (i.e.., those without bands) may not be installed in new vehicles manufactured on or after September 1, 1975. If you have any questions about these requirements, feel free to contact Mark Schwimmer of this office.#Yours truly,Richard B. Dyson,Acting Chief Counsel; |
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ID: aiam4406OpenMr. Barry Patterson, President, Patterson Incorporated, 1920 Springfield Road, Kelowna, B.C. V1Y 7R8; Mr. Barry Patterson President Patterson Incorporated 1920 Springfield Road Kelowna B.C. V1Y 7R8; Dear Mr. Patterson: This is in reply to your letter of September 21, 1987, asking for ou 'acceptance and recommendation' of a safety device endorsed' by the government of the Province of Saskatchewan. This device automatically activates parking lamps, and the lower beams of headlamps 'with the touch of the Brake Pedal'.; The National Highway Traffic Safety Administration has no authority t accept, recommend, or endorse any item of motor vehicle equipment. We can, however, discuss the relationship of your device to U.S. Federal Motor Vehicle Safety Standard No. 108, *Lamps, Reflective Devices, and Associated Equipment*, and the National Traffic and Motor Vehicle Safety Act ('the Act') under which the standard was issued. This standard applies to the manufacture and sale of new motor vehicles. A device such as yours is permissible as original vehicle equipment as long as it does not impair the effectiveness of lighting equipment required by Standard No. 108. There is no indication in your descriptive literature that the effectiveness of parking lamps, headlamps, or the stop lamps would be impaired by the installation and operation of your device.; With respect to sale in the aftermarket for vehicles in use, you device is not prohibited under the Act if its installation by a person other than the vehicle owner does not render inoperative in whole or in part any lamps installed to comply with Standard No. 108. We see no indication that this would occur. However, such an installer should be aware of the wiring requirement in Standard No. 108 that taillamps, parking lamps, side marker lamps, and the license plate lamp shall be activated when the headlamps are on.; The rules for operation of vehicles in use are established by th individual States, and several of these may have restrictions on the use of headlamps during daylight hours. For further information on this subject you should write the American Association of Motor Vehicle Administrators, 1201 Connecticut Ave., N.W., Washington, D.C. 20036.; This agency has proposed that motor vehicles be equipped with daytim running lights, in a manner similar, though not identical, to the new requirement of the Canadian Ministry of Transport. If this proposal is adopted, the Act would prohibit any State from having a different standard than the Federal one. As of the effective date of such an amendment to Standard No. 108 daytime operation of frontal lighting should be permissible in all States.; If you have any further questions we will be pleased to answer them. Sincerely, Erika Z. Jones, Chief Counsel |
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ID: aiam3021OpenMr. Robert B. Kurre, Wayne Corporation, P.O. Box 1447, Industries Road, Richmond, IN 47374; Mr. Robert B. Kurre Wayne Corporation P.O. Box 1447 Industries Road Richmond IN 47374; Dear Mr. Kurre: This responds to your May 18, 1979, letter asking to what extent th parallelepiped device required by Standard No. 217, *Bus Window Retention and Release*, must fit inside a school bus in order to provide the mandated 'unobstructed passage.'; The agency responded to a request similar to yours in 1976. A copy o that interpretation is included for your information. The essence of that interpretation is that while conducting the test in accordance with S5.4.2.1(a) of the standard, the parallelepiped device must, at a minimum, fit inside a bus so that the device's outside edge is flush with the lower outside edge of the bus body. If your bus complies with this interpretation of the standard, it would be in compliance.; Sincerely, Frank Berndt, Chief Counsel |
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ID: aiam1724OpenNancy Kolodny, Esq., Office of the General Counsel, Ford Motor Company, The American Road, Dearborn, MI 48121; Nancy Kolodny Esq. Office of the General Counsel Ford Motor Company The American Road Dearborn MI 48121; Dear Ms. Kolodny: This is in reply to your letter of June 10, 1975, asking whether Moto Vehicle Safety Standard No. 108 preempts Section 25950 of the California Vehicle Code with respect to Mercury Monarch taillamps.; Section 25950 requires in pertinent part that all lamps visible fro the rear of a vehicle be red, 'whether lighted or unlighted', except that taillamps may be white when unlighted. Standard No. 108 requires passenger car taillamps to be 'red' (Table III), and 'the taillamp indication' to be red (SAE Standard J585, *Tail Lamps*, June 1966, incorporated by reference into Standard No. 108). The taillamps on the Mercury Monarch are covered with amber lenses. Although the lamp meets the color and photometric requirements of Standard No. 108 when lighted, California is of the opinion that use of the amber lens is prohibited by Section 25950.; Section 103(d) of the National Traffic and Motor Vehicle Safety Act o 1966 prohibits a State from establishing or continuing in effect any motor vehicle safety standard applicable to the same aspect of performance of a vehicle or equipment item as a Federal standard which is not identical to it. We interpret Standard No. 108 as requiring only that the color of the taillamp 'indication' be red. The method by which this is accomplished is left to the vehicle manufacturer. The indication could be provided by a combination of a white bulb and a red lens (the conventional taillamp), a red bulb and white lens (permitted by California) or, as in your case, a red bulb and an amber lens. Although the color of the taillamp lens is not directly specified by Standard No. 108, the performance of the lamp as an assembly is covered in detail by the standard, and we consider that the color aspects of taillamps are within the scope of these requirements. If the lamp assembly complies with the Federal standard, then a State may not prohibit its use. We therefore find that in this instance 49 CFR 571.108, Federal Motor Vehicle Safety Standard No. 108, renders void the requirement of Section 25950 of the California Vehicle Code that unlighted taillamps be colored red.; Sincerely, James C. Schultz, Chief Counsel |
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ID: aiam4538OpenMr. Frank Reynolds F.E. Reynolds Associates P.O. Box 703 Marysville, OH 43040; Mr. Frank Reynolds F.E. Reynolds Associates P.O. Box 703 Marysville OH 43040; "Dear Mr. Reynolds: This is in response to your telephone conversatio with Marvin Shaw of my staff, seeking a clarification of my June 16, 1988 letter concerning school bus mirrors under Highway Safety Program Guideline No. 17. Specifically, you asked about the meaning of the phrase, 'area in front of the bus,' as used in section S9.2(b) of Standard No. 111, Rearview Mirrors (49 CFR 571.111). In your telephone conversation, you stated that a NHTSA staff person told you in a previous telephone conversation that NHTSA had defined this phrase to mean 'the area three feet in front of the bus.' NHTSA has never so interpreted this phrase in Standard No. 111. For your information, I am enclosing a June 20, 1980 letter to James Tydings that sets forth the agency's interpretation of S9.2(b) of Standard No. 111. This letter notes that the area of concern in S9.2(b) is the region in front of the bus where a driver is not able to see directly a school age child. As explained in the letter and an earlier notice (40 FR 33829, August 12, 1975), the purpose of a crossview mirror is to 'address special problems of driver visibility associated with pupil transportation,' and this type of mirror 'allows the bus driver to see the area immediately in front of a stopped bus to be sure there are no children there before moving the bus.' This letter then explains: 'The agency used the word 'view' in its ordinary, dictionary sense to mean within the range of sight. Thus, most, but not literally all, of the front bumper must be visible to the driver by use of the crossview mirror to ensure that he or she can see children standing in front of the bus.' This is still an accurate expression of the agency's interpretation of the purpose of a crossview mirror and this phrase. In your telephone conversation, you also expressed concern about the 'legal effect' of Standard No. 111. You should be aware of 108 (a)(1)(A) of the Safety Act which states that No person shall manufacturer for sale, sell, offer for sale, or introduce or deliver for introduction in interstate commerce, or import into the United States, any motor vehicle or item of motor vehicle equipment manufactured on or after the date any applicable Federal motor vehicle safety standard takes effect under this title unless it is in conformity with such standard except as provided in subsection (b) of this section. I hope this information is useful. If you have any additional questions, or need further information on this subject, please feel free to contact Mr. Shaw at this address or by telephone at (202) 366-2992. Sincerely, Erika Z. Jones Chief Counsel Enclosure"; |
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ID: aiam5293OpenMr. Maine E. Peace, Jr. Supervising Revenue Officer State of Washington Department of Revenue P.O. Box 1176 Bellingham, WA 98327; Mr. Maine E. Peace Jr. Supervising Revenue Officer State of Washington Department of Revenue P.O. Box 1176 Bellingham WA 98327; Dear Mr. Peace: This is in response to your FAX of August 3, 1993, t Robert Hellmuth, Director of the Office of Vehicle Safety Compliance, with respect to the disposition of Canadian vehicles seized in the State of Washington for violations of Washington law regarding the possession and transportation of illegal cigarettes. I apologize for the delay in our response. You have requested that we 'provide authority for the Department of Revenue to sell the vehicles locally even tho (sic) they were manufactured in Canada, providing of course the vehicles meet most if not all the standards regulated by your agency regarding vehicle safety.' Section 108(a)(1)(A) of the National Traffic and Motor Vehicle Safety Act (the Safety Act, 15 U.S.C. 1397(a)(1)(A)) provides, among other things, that no person shall import into the United States any motor vehicle that does not comply with U.S. safety standards. When a vehicle that doesn't meet the U.S. safety standards crosses the border from Canada into the United States, its driver is regarded as the importer, and, unless the driver or circumstances indicate otherwise, we view the importation as a temporary one by a non- resident for his or her personal use, and hence, permissible. However, if the State of Washington were to seize the vehicle and sell it locally, the action of the State would have the effect of converting the temporary importation of a non-conforming vehicle into a permanent one. We believe that such action would be inconsistent with the Safety Act's requirement that no person import into the United States any motor vehicle that doesn't meet U.S. safety standards. Non-conforming Canadian vehicles are admitted into the United States on the condition that they will be exported back to Canada within one year. We believe that the most appropriate way for the State of Washington to dispose of the vehicles would be to export them back to Canada. If you have any further questions, we shall be pleased to consider them. Sincerely, John Womack Acting Chief Counsel; |
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ID: aiam3577OpenMr. Arthur L. Smith, 2401 W. Southern Avenue, B-294, Tempe, AZ 85282; Mr. Arthur L. Smith 2401 W. Southern Avenue B-294 Tempe AZ 85282; Dear Mr. Smith: This is in response to your letter of March 12, 1982. We are sorry fo the delay in our response. In your letter you raised the question of whether devices which tow vehicles without the odometer registering the towed mileage violate the Federal odometer laws.; An odometer is an instrument which measures and records the actua distance a motor vehicle travels while in operation. The odometer is operated from a gear on the vehicle's transmission. Apparently the odometer does not register mileage when a vehicle is being towed with one of the devices described in your letter because these devices disconnect the transmission.; Congress determined that purchasers of motor vehicles rely heavily o the odometer reading as an index of the condition and value of the vehicle and therefore established certain safeguards to ensure that the odometer reading is an accurate reflection of the mileage traveled by the vehicle. Motor Vehicle Information and Cost Savings Act ('Act') (15 U.S.C. 1981 *et seq*.), Odometer Disclosure Requirements (49 CFR Part 580). Specifically, the Act prohibits the disconnection, resetting or alteration of a vehicle odometer with the intent to change the number of miles registered on the odometer. 15 U.S.C. 1984. The Act also prohibits the advertisement, sale, use or installation of any device which causes an odometer to register any mileage other than the true mileage driven. 15 U.S.C. 1983.; While the Act does not define 'mileage traveled by a vehicle,' nothin in the Act or the legislative history suggests that Congress intended these words to have a meaning other than their common sense meaning. The common sense usage of 'mileage traveled by a vehicle' in our opinion includes both the mileage traveled when the vehicle is operated by its own power and, (sic) when it is towed. Towing a vehicle exerts wear and tear on critical components other than the vehicle's engine. Indeed, towing so affects the condition of the vehicle, it would have been illogical for Congress to exclude this mileage from the Federal odometer requirements. Therefore for purposes of the Federal odometer laws a vehicle is traveling when it is towed and devices which cause the odometer not to register such mileage are prohibited by the Act.; Because we do not have sufficient information concerning the device which you described in your letter, and the advertisements do not supply all necessary details, we are unable to conclude at this time whether any violation of law has occurred with respect to these particular devices.; Sincerely, Frank Berndt, Chief Counsel |
Request an Interpretation
You may email your request to Interpretations.NHTSA@dot.gov or send your request in hard copy to:
The Chief Counsel
National Highway Traffic Safety Administration, W41-326
U.S. Department of Transportation
1200 New Jersey Avenue SE
Washington, DC 20590
If you want to talk to someone at NHTSA about what a request for interpretation should include, call the Office of the Chief Counsel at 202-366-2992.
Please note that NHTSA’s response will be made available in this online database, and that the incoming interpretation request may also be made publicly available.