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: aiam1442OpenHonorable Frank Thompson, Jr., House of Representatives, Washington, DC 20515; Honorable Frank Thompson Jr. House of Representatives Washington DC 20515; Dear Mr. Thompson: This responds to your March 19, 1974, request for information in behal of Mr. Robert J. Jones, concerning the commercial offer he received for a device that would defeat the ignition interlock device found on 1974 model passenger cars.; The National Traffic and Motor Vehicle Safety Act of 1966 authorize the issuance of motor vehicle safety standards, one of which requires occupant crash protection, one aspect of which is the ignition interlock system. Section 108(a)(1) of the Act prohibits the sale, offer for sale, introduction into interstate commerce, or the importation of any motor vehicle which does not conform to the standards. Our regulatory authority over new vehicles ends, however, with the first purchase of the vehicle in good faith for purposes other than resale. While we can prohibit arrangements between a dealer and a purchaser to disconnect the interlock, where they are part of the sales transaction, we have no remedy against arrangements to defeat the safety features made after the sales transaction.; Nevertheless, while selling devices intended to defeat safety equipmen may be legal, we consider such practices reprehensible since they increase the chances of death and injury on the highways. We are considering a variety of remedies for the situation reported by Mr. Jones.; Sincerely, Lawrence R. Schneider, Chief Counsel |
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ID: aiam5401OpenMr. R. H. Goble President, Goble Enterprises P.O. Box 423 Lake Mary, FL 32795; Mr. R. H. Goble President Goble Enterprises P.O. Box 423 Lake Mary FL 32795; "Dear Mr. Goble: This is in reply to your letter of May 16, 1994, wit respect to two motor vehicle lighting systems that you have developed, and your question about the regulations that may apply to each. As we understand the first system, when the brake pedal is applied, the front turn signal lamps and front side marker lamps are simultaneously activated to indicate to observers from the front and side that the vehicle is braking. It appears that this activation is in a steady burning state which continues unless and until the turn signal lamps are activated in either the flashing turn signal or hazard warning signal more. You have also developed a 'Wheel Well lighting system', which 'will provide light indicators all around (brake, clearance, turn signal, emergency flashers)' through amber lamps mounted in the well at the top of each front and rear wheel opening. As we understand this system, these supplementary lamps will be activated simultaneously when the four named lamp systems are activated. The regulation governing the lighting on new motor vehicles (i.e., requirements that must be met when a new vehicle is delivered to its first purchaser) is Federal Motor Vehicle Safety Standard No. 108. With respect to optional equipment such as your systems, Standard No. 108 allows each, provided that each does not impair the effectiveness of the lighting equipment required by the standard. The law governing the lighting on motor vehicles after their first sale is the National Traffic and Motor Vehicle Safety Act. In essence, it allows installation of each of your systems by a manufacturer, dealer, distributor, or motor vehicle repair business as long as the system does not 'knowingly render inoperative, in whole or part, any device or element of design installed in accordance with' Standard No. 108. We regard any supplemental lighting system with the potential of creating confusion in the eye of the beholder as one that impairs the effectiveness of other lamps on the vehicle, and one that renders inoperative, in part at least, other lamps by compromising their effectiveness. This is especially true when existing vehicle lamps are used to convey messages that are different from the purpose of those lamps. We believe it especially important to motor vehicle safety that signal lamps convey their message unmistakably and without ambiguity. We see no real problem that might be occasioned by the activation of the front turn signal lamps in a steady burning mode, although this might cause initial puzzlement in the eye of an oncoming driver unfamiliar with the system. While confusion is more likely when the turn signal is operating on one side while the other side remains steady burning, we believe that the flashing of the turn signal will continue to be interpreted as an intention to turn. Of course, when the hazard warning system is activated and completely overrides the steady burning front stop lamp, there would be no confusion as to signal message. Therefore, in our opinion, Federal law permits use of your front stop lamp system. Your second system does not operate through existing vehicle lamps but consists of additional lamps mounted in the wheel wells. These lamps would appear not to have the potential of confusion since they supplement existing lamps and operate in conjunction with them to convey the same message. Thus, Federal law, in our view, does not preclude use of your second system either. However, even if a supplementary lighting system is permissible under Federal law, it is subject to regulation by any State in which it is operated. We are not able to advise you with respect to State law, and suggest that you write for an opinion to the American Association of Motor Vehicle Administrators, 4600 Wilson Boulevard, Arlington, Va. 22203. Sincerely, John Womack Acting Chief Counsel"; |
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ID: aiam0603OpenMr. G. Utsunomiya, Liaison Engineer, Chief, Toyo Kogyo Co., Ltd., 3841 Mystic Valley Drive, Bloomfield Hills, MI, 48013; Mr. G. Utsunomiya Liaison Engineer Chief Toyo Kogyo Co. Ltd. 3841 Mystic Valley Drive Bloomfield Hills MI 48013; Dear Mr. Utsunomiya: This is in reply to your letter of January 28, 1972, in which you lis specific interior components and ask whether they are required to comply with Standard No. 302, 'Flammability of Interior Materials.' You state that these components are not designed to be energy absorbing in some vehicles.; With regard to the parcel shelf and scarf plate, as we indicated to yo in our letter of September 24, 1971, these components appear to closely resemble or to be merely different descriptions of items that are enumerated in S4.1 of Standard No. 302. If so, they must comply with the requirements. We also mentioned to you in that latter than seaming welt and seaming rubber should be considered as part of the component to which it is attached, and for which it provides a seam.; With regard to the other items you list, you should consider th language of S4.1 that reads, '. . . other interior materials . . . designed to absorb energy on contact by occupants in the event of a crash.' If in fact, as you indicate, these components are not so designed, then they need not meet the requirements of the standard. I would add that NHTSA is presently reviewing this requirement, and it may be modified in the near future.; Yours truly, Richard B. Dyson, Assistant Chief Counsel |
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ID: aiam1911OpenMr. Ivan J. Wagar, President, Safety Helmet Council of America, 9841 Airport Boulevard, Suite 1208, Los Angeles, CA 90045; Mr. Ivan J. Wagar President Safety Helmet Council of America 9841 Airport Boulevard Suite 1208 Los Angeles CA 90045; Dear Ivan: This is in response to your recent letter requesting clarification o two points concerning motorcycle helmet dealers' responsibilities under Standard 218.; You ask first about the penalties which would apply to 'dealers wh knowingly sell non DOT labeled helmets for on-road use.' Section 108 of the National Traffic and Motor Vehicle Safety Act (15 U.S.C. 1397) reads in pertinent part:; >>>'No person shall...sell, offer for sale, or introduce or deliver fo introduction into 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 subchapter unless it is in conformity with such standard ...'<<<; Section 109 of the Act (15 U.S.C. 1398) provides for civil penalties o up to $1000 for each violation, up to a maximum of $800,000 for any related series of violations. Each sale or offer for sale constitutes a separate violation of the Act.; As you know, Standard 218 applies only to helmets fitting the size headform and manufactured after February 28, 1974. Thus, dealers may continue to sell size C helmets manufactured before March 1, 1974. We have taken the position that any helmets designed to fit a range of head sizes that includes the approximate dimensions of the size C headform must meet the requirements of Standard 218. A helmet is considered not to fit a size C headform only if it is clearly intended by its manufacturer to be used only by persons whose heads are either larger or smaller than the size C headform.; With regard to racing or other off-road helmets we have taken th position that such helmets must be clearly and prominently labeled as not for use on public highways. The following label was considered acceptable:; >>>IMPORTANT: THIS HELMET IS MANUFACTURED FOR RACING AND SIMILA OFF-ROAD SPORTS ONLY, AND IS NOT REGULATED BY THE U.S. DEPARTMENT OF TRANSPORTATION. IT IS NOT FOR USE ON PUBLIC STREETS, ROADS AND HIGHWAYS.<<<; You ask further whether helmet manufacturers must keep records of firs purchasers. The answer is no. NHTSA believes that keeping such records is a sound business practice which is generally necessary in connection with a responsible warranty program, but this agency presently requires such recordkeeping only by motor vehicle and tire manufacturers, not by equipment manufacturers.; I enclose a copy of the Act which incorporates the 1974 amendments. I I can be of further assistance in your worthwhile and much needed educational program please let me know.; Yours truly, Richard B. Dyson, Assistant Chief Counsel |
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ID: aiam2794OpenCary C. Boyden, Hayward Air Plaza, Suite 220, 22693 Hesperian Boulevard, Hayward, CA 94541; Cary C. Boyden Hayward Air Plaza Suite 220 22693 Hesperian Boulevard Hayward CA 94541; Dear Mr. Boyden: This is in response to your letter of February 22, 1978, concerning th Federal odometer requirements.; The question you raised was whether the lessor can leave th transferee's name and address on the odometer disclosure statement blank in cases where the transferee is a bank who has not yet determined whether the vehicle will be leased or the subject of a secured lending arrangement.; As defined in 49 CFR S 580.3, 'Transferee' means 'any person to who the ownership in a motor vehicle is transferred by purchase, gift, or any means other than by creation of a security interest.' Therefore, if the bank is taking possession of the vehicle in order to lease it, the lessor should indicate that the bank is the transferee. If the bank is taking possession of the vehicle in order to make it the subject of a secured lending arrangement, the bank's customer, and not the bank, should appear on the disclosure statement as transferee.; You indicated that additional paper work would result if the bank wer required to be listed as the transferee in both of the above situations until it decided how to dispose of the vehicle. As a result, you suggested that it be acceptable to list as transferee the bank or its customer as their respective interest may appear. You stated that 'this alternative would allow the bank either to retain the statement on its own behalf or to forward the disclosures to the ultimate debtor at the time it is determined to consummate the transaction as a secured loan rather than a lease.'; It is our opinion that your proposed alternative is acceptable under 4 CFR Part 580, so long as the bank transmits the disclosure to the transferee. The lessor, as transferor, would be responsible for furnishing the transferee with the statement. Should the bank fail to transmit the statement, the lessor could be held responsible for the bank's negligence.; Sincerely, John Womack, Assistant Chief Counsel |
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ID: aiam5051OpenMr. Mark V. Schwartz Account Executive Entran Devices, Inc. 10 Washington Avenue Fairfield, NJ 07004; Mr. Mark V. Schwartz Account Executive Entran Devices Inc. 10 Washington Avenue Fairfield NJ 07004; "Dear Mr. Schwartz: This responds to your request for an interpretatio of 49 CFR Part 572, Anthropomorphic Test Dummies. Specifically, you were interested in the provisions for the Hybrid III test dummy set forth in Subpart E of Part 572. You noted that 572.36(g) provides that the thorax and knee impactor accelerometers 'shall have the dimensions and characteristics of Endevco Model 7231c or equivalent.' You provided a sheet setting forth dimensional and electrical response information for an accelerometer model produced by your company, the Entran EGE-72C-750. You then asked if the Entran EGE-72C-750 was 'equivalent' to the Endevco Model 7231c, within the meaning of 572.36(g). I am pleased to have this opportunity to explain our regulation for you. Part 572 sets forth specifications with which all test dummies must comply if those dummies are to be used in this agency's compliance testing. In NHTSA's compliance testing to date, we have used only the Endevco Model 7231c for the thorax and knee impactor accelerometers. This should not be misinterpreted as suggesting that this agency believes that only this particular make and model of accelerometer will perform acceptably in compliance testing. Instead, it means that the agency has found that the Endevco Model 7231c performs acceptably in the intended shock environment, in terms of frequency response characteristics, damping, linearity, transverse sensitivity, reliability, repeatability, durability, etc. The dictionary defines 'equivalent' as 'equal in value, measure, force, effect, significance, etc.' As noted above, NHTSA has used only the Endevco Model 7231c for the thorax and knee impactor accelerometers in the compliance testing to date. Thus, the agency has not made any determination of which accelerometers are equivalent to the Endevco Model 7231c. Until such time as the agency makes a determination about equivalent accelerometers, the issue of equivalency of your EGE-72C-750 model and the specified accelerometer model is a matter to be worked out between your company and prospective users of your company's accelerometers. As long as you can satisfy prospective users about the equivalence of your company's accelerometers, NHTSA will not review the use of any particular accelerometers in certification testing, unless the test results indicate a problem or problems caused by those accelerometers. I hope this information is helpful. If you have any further questions or need some additional information on this subject, please feel free to contact Steve Kratzke of my staff at this address or by telephone at (202) 366-2992. Sincerely, Paul Jackson Rice Chief Counsel"; |
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ID: aiam3886OpenMr. Rod L. Stafford, Fryford Corporation, 2nd Seat, 982 North Batavia, Unit B-12, Orange, CA 92667; Mr. Rod L. Stafford Fryford Corporation 2nd Seat 982 North Batavia Unit B-12 Orange CA 92667; Dear Mr. Stafford: This responds to your recent letter requesting information on which o the agency's regulations would apply to a new product you are considering. You described the product as a 'hammock-like seat which, unrolled and fastened into the rear bed of any pickup truck, forms a comfortable passenger seat which may be easily stowed inside the truck cab.' You stated that you plan to sell your product as an item of aftermarket equipment and asked about the application of our regulations to your product.; If your product is sold as an item of aftermarket equipment to b installed by a vehicle owner, it would not be required to comply with Standards Nos. 207, 208, 209, 210, and 302. We were pleased to learn that you have nevertheless voluntarily designed your product to conform to those standards.; As a manufacturer of an item of motor vehicle equipment, you do have responsibility under section 151 *et seq*. of the National Traffic and Motor Vehicle Safety Act to conduct a notification and remedy campaign if you or the agency determines that your product contains a safety-related defect or does not comply with an applicable standard. A copy of the Act is enclosed.; If you have any further questions, please let me know. Sincerely, Frank Berndt, Chief Counsel |
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ID: aiam0253OpenMr. Boyd W. Finkel, Vice President, Universal Tire Corporation, 4622 Southlawn Lane, Rockville, Maryland 20850; Mr. Boyd W. Finkel Vice President Universal Tire Corporation 4622 Southlawn Lane Rockville Maryland 20850; Dear Mr. Finkel: The Office of Trade Regulation Rules of the Federal Trade Commissio has forwarded your letter of July 30, 1970, concerning tires marked 'Radial' that have casing cord angles that vary as much as 15 degrees from 90 degrees.; Paragraph S3 of Motor Vehicle Safety Standard No. 109 -- New Pneumati Tires, Passenger Cars -- defines a radial ply tire as a 'pneumatic tire in which the ply cords which extend to the beads are laid at substantially 90 degrees to the centerline of the tread'.; The Bureau does not consider cords laid a 75 degrees to the centerlin of the trend as 'Radial' tires and tires marked as much(sic) would not be incompliance with the tire standard.; Persons importing tires that do not comply with the standard would b violating section 108(a)(1) of the National Traffic and Motor Vehicle Safety Act of 1966 (15 U.S.C. 1397).; For your information enclosed is a copy of the Passenger Car Tir Standard and the National Traffic and Motor Vehicle Safety Act.; Sincerely, Lawrence R. Schneider, Acting Deputy Chief Counsel |
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ID: aiam0746OpenMr. Kenneth Koehler, Harold Schlintz & Associates, 3752 E. Belmont Avenue, Fresno, CA 93702; Mr. Kenneth Koehler Harold Schlintz & Associates 3752 E. Belmont Avenue Fresno CA 93702; Dear Mr. Koehler: This is in reply to your letter of June 8, 1972, to Robert L. Carter as to whether Federal Motor Vehicle Safety Standard No. 206 is applicable to a White 'Freightliner' which was manufactured on or about December 1, 1970.; The White Freightliner, as illustrated in the picture you enclosed, i a truck tractor, and is classified as a 'truck' under the motor vehicle safety standards. Standard No. 206 became applicable to trucks on January 1, 1972, and would not therefore apply to this truck. No other standards are applicable to the doors or door latches of this vehicle.; The standards do not apply to a vehicle after its first sale to consumer (a used vehicle), and no exemption from the standards is necessary.; Yours truly, Richard B. Dyson, Assistant Chief Counsel |
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ID: aiam3869OpenMr. Herbert R. Apuzzo, Laboratory Supervisor, American Safety Equipment Corporation, Corporate Quality Assurance & Reliability, 11441 Bradley Avenue, Pacoima, CA 91331; Mr. Herbert R. Apuzzo Laboratory Supervisor American Safety Equipment Corporation Corporate Quality Assurance & Reliability 11441 Bradley Avenue Pacoima CA 91331; Dear Mr. Apuzzo: This responds to your letter of September 25, 1984, to Mr William Smit which was forwarded to this office for reply. You asked several questions concerning the requirements of section 5.2(b) of Standard No. 209, *Seat Belt Assemblies*, which are answered below.; Your first question concerns the conditioning requirements of Procedur D of ASTM D756-78, which is incorporated by reference in Standard No. 209. You pointed out that the agency's compliance test procedure (document TP-209- 01) calls for conditioning for 24 hours, while ASTM D756-78 calls for conditioning for not less than 40 hours. The conditioning requirement incorporated by reference in Standard No. 209 is the correct version and is the method which will be used by the agency. The version of the agency's compliance test procedure you cite was prepared before the June 30, 1983, amendments to Standard No. 208 which adopted ASTM D756-78. The compliance test procedure will be revised to specify not less than 40 hours of conditioning.; Your second question concerned the requirement of Procedure D that par of the testing be done in a sealed container placed over water in a 176 degrees F recirculating oven. The test calls for maintaining 'a humid atmosphere' in the sealed container. You asked what percentage of humidity should be maintained.; You are correct that Procedure D does not specify the specifi percentage of humidity. However, section 6.2, *Test conditions*, of ASTM D756-78 specifies that the tests should be conducted in the Standard Laboratory Atmosphere of 23 plus or minus 2 degrees C and 50 plus or minus 5% relative humidity 'unless otherwise specified in the test methods or in this practice.' Since Procedure D does not specify a humidity level, the agency will use the humidity of 50 plus or minus 5% relative humidity specified in section 6.2.; You also asked whether a recirculating chamber can be used to conduc the test. The test equipment specified in the standard is the equipment the agency will use in its compliance tests. Manufacturers are free to use other test equipment as long as they can make a good faith certification that their product complies with the requirements set in the standard.; Your final question concerns another difference between ASTM D756-7 and the compliance test procedure. As explained above, the version of the compliance test procedure you cite was prepared before the June 1983 amendments to the standard and will be updated to cite the requirements adopted in those amendments. You asked for a description of 'dessicator'(sic) and 'uncharged dessicator'(sic) referred to in ASTM D756-78. A dessicator (sic) is a closed container that has a drying agent to absorb moisture. An 'uncharged dessicator'(sic) is a dessicator (sic) that does not have a test specimen in it.; In addition, you asked whether you could use an environmental chambe rather than a dessicator (sic). As discussed previously, the test procedures and equipment specified in the standard are the procedures and equipment which the agency will use in its compliance tests. Manufacturers are free to use other test equipment and procedures as long as they can make a good faith certification that their product complies with the requirements set in the standard.; If you have any other questions, please let me know. Sincerely, Frank Berndt, Chief Counsel |
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Request an Interpretation
You may email your request to Interpretations.NHTSA@dot.gov or send your request in hard copy to:
The Chief Counsel
National Highway Traffic Safety Administration, W41-326
U.S. Department of Transportation
1200 New Jersey Avenue SE
Washington, DC 20590
If you want to talk to someone at NHTSA about what a request for interpretation should include, call the Office of the Chief Counsel at 202-366-2992.
Please note that NHTSA’s response will be made available in this online database, and that the incoming interpretation request may also be made publicly available.