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: aiam3584OpenMr. Bernard S. Horton, 100 Memorial Drive, Cambridge, MA 02142; Mr. Bernard S. Horton 100 Memorial Drive Cambridge MA 02142; Dear Mr. Horton: This responds to your recent letter regarding the roof crus requirements of Federal Motor Vehicle Safety Standard No. 216. You ask why convertibles are excluded from the requirements of the standard, yet the BMW 318 which has a 'targa' roof is not excluded.; Convertibles were excepted from Safety Standard No. 216 when th standard was first issued in 1971 because it was impossible for most convertibles to comply with the requirements. The legislative history of the National Traffic and Motor Vehicle Safety Act of 1966 (15 U.S.C. 1381, et seq.), which authorizes the issuance of our safety standards, clarifies that Congress did not intend for the safety standards that would be issued to effectively preclude any type of existing motor vehicle. If no exception had been provided, the requirements of Safety Standard No. 216 would have caused the production of convertibles to cease. For this reason alone, they were excepted from the requirements.; The agency has limited the convertible exception to vehicles for whic it is truly impractical to comply. While our regulations do not include a formal definition of 'convertible', the agency has stated that it considers a convertible to be a vehicle whose 'A' pillar or windshield peripheral support is not joined with the 'B' pillar (or rear roof support rearward of the 'B' pillar position) by a fixed rigid structural member. Therefore, passenger cars equipped with a 'sun roof', 'hurst hatch roof' or 'targa roof' do not qualify as convertibles because they have a fixed rigid structural member in the described location. This interpretation applies, moreover, whether the rigid structural member joining the 'A' and 'B' pillars is a hidden reinforcing component or whether the structural member is part of the exterior roof panel.; I am sorry that you are unable to obtain the BMW 318, but this i primarily due to the fact that the manufacturer has chosen not to bring this model into compliance with Safety Standard No. 216. As you probably know, there are other models with 'targa roofs' and 'hurst roofs' that are in compliance with the standard and currently in use.; You also mention the fact that many vehicle custom shops cut one o more panels from vehicles to make them into convertibles or 'targas'. You state that there seems to be no prohibition to this. There are certain prohibitions, however. Section 108(a)(2)(A) of the Vehicle Safety Act specifies that no manufacturer, distributor, dealer or motor vehicle repair business shall knowingly render inoperative in whole or part any device or element of design installed on or in a motor vehicle in compliance with a motor vehicle safety standard. This means that custom shops cannot cut panels from a used vehicle's roof if such operation would impair the vehicle's compliance with Safety Standard No. 216. Failure to observe this prohibition could result in civil penalties up to $1,000 for each violation. Please note, however, that custom shops are not precluded by this section from totally removing a vehicle roof, thereby converting the vehicle into a convertible. The prohibition does not apply to such a conversion since the vehicle would not have had to comply with Standard No. 216 if it had originally been manufactured as a convertible.; I realize that these various distinctions may be confusing. If you hav any further questions, please contact Hugh Oates of my staff at 202- 426-2992.; Sincerely, Frank Berndt, Chief Counsel |
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ID: 86-5.14OpenTYPE: INTERPRETATION-NHTSA DATE: 09/05/86 EST FROM: ERIKA Z. JONES -- CHIEF COUNSEL NHTSA TO: JOSEPH A. GIAMPAPA TITLE: NONE ATTACHMT: LETTER DATED 02/13/86, TO ERIKA Z JONES, FROM JOSEPH A GIAMPAPA, REGULATIONS, OCC-0202 TEXT: Dear Mr. Giampapa: This responds to your letter dated February 13, 1986, regarding an auto body gauge which a client intends to manufacture. The accompanying material describes this device as "a gauge for aligning opposite points within opposite surfaces of a normally symmetric body." It could be used to align a vehicle body following damage in an accident or collision. You ask what Federal requirements are applicable to an auto body gauge. I regret the delay in responding to your letter. This agency administers the National Traffic and Motor Vehicle Safety Act of 1966, as amended (15 U.S.C. 1391 et seq.). Under section 103 of the Act, NHTSA has issued Federal motor vehicle safety standards which are applicable to new motor vehicles and their equipment. The auto body gauge described in your letter would apparently be used by commercial automobile repair businesses when repairing and realigning damaged car bodies. In previous interpretations, NHTSA has said that items, such as wheel balancing machines, are "repair shop" equipment and not "motor vehicle" equipment. The reason is that, although their only use is with a motor vehicle, they are not intended to be used principally by ordinary users of motor vehicle equipment. Thus, we would not consider your client's product an item of motor vehicle equipment. I hope this information is helpful to you. Sincerely |
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ID: aiam0951OpenMr. Richard H. Trampenau, Marketing Specialist, DION FR Polyester Resins, Diamond Shamrock Chemical Company, P. O. Box 829, Redwood City, CA, 94064; Mr. Richard H. Trampenau Marketing Specialist DION FR Polyester Resins Diamond Shamrock Chemical Company P. O. Box 829 Redwood City CA 94064; Dear Mr. Trampenau: This is in reply to your letters of October 9 and December 4, 1972 concerning the application of Motor Vehicle Safety Standard No. 302, 'Flammability of Interior Materials', to motor homes and other multipurpose passenger vehicles.; You ask whether 'molded plastic exterior shells' of motor homes an other vehicles must meet the burn rate requirement of the standard, even when they are completely though variously covered in the vehicle interior. The answer to this question in both respects is no. Whether a material is subject to the requirement depends on whether it is used for producing any of the components listed under Paragraph S4.1 of the standard, either as a surface material, an underlying material, or a padding and cushioning material. Motor vehicle shells are not listed under Paragraph S4.1 and, therefore, they are not subject to the requirements of the standard.; You also ask whether 'molded plastic engine covers, separating th engine compartment from the passenger compartment,' must meet the burn rate requirement of the standard, even when they are completely though variously covered in the vehicle interior. Engine compartment covers are listed under Paragraph S4.1 of the standard, but they are subject to the requirements, as are all the listed components, only to the extent that they are part of the occupant compartment. Any material in the vehicle occupant compartment which covers that part of the engine compartment in juxtaposition with the occupant compartment would be considered an engine compartment cover. Under Paragraph S4.2 the portion of the engine compartment cover that must meet the requirements, as for any of the listed components, depends on whether the surface material is bonded, sewed, or mechanically attached to underlying material and thereby achieves an intimate joining of materials which are normally separate. The important question, then, is not so much how the covering for the molded plastic is attached, but how closely spaced are the attachment points. If the covering is not bonded, sewed, or mechanically attached to the underlying molded plastic so that an intimate joining is not achieved, then the covering would be considered the engine compartment cover and, under Paragraph S5.2.1, the thickness of the portion to be tested 'is that of the material as used in the vehicle, except that where the material's thickness exceeds 1/2 inch the specimen is cut down to that thickness.' On the other hand, if the covering and the molded plastic are attached so that an intimate joining is achieved, then the covering and the molded plastic would together be considered the engine compartment cover and, again under Paragraph S5.2.1, the thickness of the portion to be tested 'is that of the (composite) material as used in the vehicle, except that where the (composite) material's thickness exceeds 1/2 inch the specimen is cut down to that thickness.'; The manner of attachment, if any, of the molded plastic to its coverin does not affect the burn rate requirement. Where structural equipment such as shelves and bunks completely cover the molded plastic which separates the engine compartment from the passenger compartment, the engine compartment cover would not be subject to the requirements of the standard. However, should the structural equipment not completely cover the molded plastic engine cover, then it must meet the requirements.; Yours truly, Richard B. Dyson, Assistant Chief Counsel |
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ID: Harness_and_LATCHOpenMr. Terry Emerson Dear Mr. Emerson: This responds to your letter of July 12, 2001, asking "Is the Cosco Travel Vest required to be LATCH compatible by September 1, 2002?" Stated differently, you ask whether child restraint vest systems are required by Standard No. 213 to have attachments that enable the restraint to connect to a child restraint anchorage system on a vehicle (49 CFR 571.225). (1) The answer to your question is no. According to the marketing literature you enclosed with your letter, the Travel Vest is a 5-point harness restraint. Section 5.9(a) of Standard No. 213 (49 CFR 571.213) excludes harnesses from the requirement in the standard that child restraints must have components that attach to the lower anchorages of a LATCH system. We excluded harnesses out of practicability concerns. We did not know whether harnesses had a structural member that was strong enough to withstand the forces that would be imposed on it by the LATCH connectors. (See LATCH final rule, 64 FR 10786, 10808; March 5, 1999.) I hope this information is helpful. If you have any questions, please feel free to contact Deirdre Fujita at this address or at (202) 366-2992. Sincerely, John Womack ref:213
1. 1 "LATCH" is a term used by industry and retail groups referring to the child restraint anchorage system required by Standard No. 225. LATCH stands for "lower anchorages and tethers for children." For convenience, we will use the term in this letter. |
2001 |
ID: aiam5431OpenMr. Jerry Miller Director of Operations Associated Leasing Handicapable Vans 12117 Riverwood Drive Burnsville, MN 55337; Mr. Jerry Miller Director of Operations Associated Leasing Handicapable Vans 12117 Riverwood Drive Burnsville MN 55337; Dear Mr. Miller: This responds to your letter of May 31, 1994 requesting confirmation that 'there are no rules or regulations on wheelchair tie downs for vehicles other than school buses.' You are correct that Federal motor vehicle safety standard No. 222, School Bus Passenger Seating and Crash Protection, which includes requirements for wheelchair securement devices, applies only to school buses. However, while none of the safety standards apply to wheelchair securement devices for vehicles other than wheelchairs, the manufacturer of the product is subject to federal requirements concerning the recall and remedy of products with defects related to motor vehicle safety (49 U.S.C. 30118-30121). The agency does not determine the existence of defects except in the context of a defect proceeding. You should also be aware that the Department of Transportation has issued a final rule implementing the transportation provisions of the Americans with Disabilities Act. This final rule includes requirements for wheelchair securement devices installed in vehicles required to be accessible by this rule. A copy of the final rule is enclosed with this letter. If you have further questions on these regulations, please contact Mr. Irv Chor of the Federal Transit Administration. Mr. Chor's card is attached to the final rule. I hope you find this information helpful. If you have any other questions concerning NHTSA regulations, please contact Mary Versailles of my staff at this address or by phone at (202) 366-2992. Sincerely, John Womack Acting Chief Counsel Enclosure; |
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ID: nht92-5.29OpenDATE: July 7, 1992 FROM: Paul Jackson Rice -- Chief Counsel, NHTSA TO: Guy Dorleans -- International Regulatory Affairs Manager, Valeo TITLE: None ATTACHMT: Attached to letter dated 5/25/92 from Guy Dorleans to Chief Counsel, NHTSA TEXT: This responds to your letter of May 25, 1992, asking for confirmation that your interpretation of Motor Vehicle Safety Standard No. 108 is correct. As you state, "Standard No. 108 specifies different levels of photometric requirements for signal lamps, depending on the number of lighted sections which they have", whether there are one, two, or three such sections (see Figure 1b). You further state that "the use of light-emitting diodes does not permit to distinguish at a glance several distinct lighted sections." Thus, when a single diode fails, "a variation will be easy to identify." Where "light-emitting diodes . . . are used in quantities bigger than three, we consider that the provision for 'lamps with three lighted sections' applies a fortiori, because its severeness will keep the user on the safe side, even though the standard does not specifically address the problems raised by the multiple light sources." Standard No. 108 incorporates by reference two different SAE standards for turn signal lamps, J1395 APR85 for vehicles 2032mm or more in overall width, and J584 NOV84 for narrower vehicles. SAE J1395 establishes luminous intensity minima and maxima photometric requirements without reference to either compartments or lighted sections, and all that is required is for the lamp to comply at the individual test points specified. Section S5.1.1.31 clarifies that measurements of a multiple compartment turn signal lamps on vehicles to which SAE J1395 APR85 applies are to be made for the entire lamp and not for the individual compartments. However, SAE J584 NOV84 continues to specify different minimum photometric requirements for one, two, and three "lighted sections." Because the SAE does not prescribe photometric requirements for more than three lighted sections, we have concluded that any device that contains more than three lighted sections need only comply with the requirements prescribed for three lighted sections. |
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ID: aiam4168OpenMr. Robert H. Munson, Director, Automotive Safety Office, Ford Motor Company, The American Road, Dearborn, MI 48121; Mr. Robert H. Munson Director Automotive Safety Office Ford Motor Company The American Road Dearborn MI 48121; Dear Mr. Munson: This is to follow-up on a phone conversation between Mr. William Kin of Ford Motor Company's Washington Office and Stephen Oesch of my staff concerning the initial knee spacing requirements of Standard No. 208, *Occupant Crash Protection*. Mr. King referred to a memorandum in the public docket on Standard No. 208 which summarizes a meeting held between representatives of General Motors Corporation (GM) and this agency on April 16, 1986, and asked when the agency plans to reinstate the 14.5 inch requirement for the initial spacing of the driver test dummy's knee's (sic).; As discussed in the memorandum summarizing the April 16, 1986 meeting the agency misinterpreted the comments made by GM and Honda Motor Company on the initial knee spacing requirement proposed in April 1985. As a result of that misinterpretation, the agency adopted a (sic) 11 3/4 requirement for the initial spacing of the driver test dummy's knees in the March 21, 1986 final rule on the test dummy positioning procedures, rather than the proposed 14 1/2 inch requirement. The memorandum said that the agency planned to publish a correction notice on the test dummy positioning procedure to reinstate the 14 1/2 dimension for the initial spacing of the driver test dummy's knees.; Subsequent to the April 16, 1986 meeting, Ford filed a petition fo reconsideration of many of the test dummy positioning and other requirement (sic) adopted in the March 1986 final rule. The agency will make the necessary correction to the initial knee spacing requirement for the test dummy at the time it responds to Ford's petition for reconsideration.; Manufacturers can rely on this letter, which will be placed in th public docket on Standard No. 208, as assurance that they can use the 14 1/2 inch initial knee spacing requirement for the driver test dummy in conducting compliance tests for Standard No. 208.; If you have any further questions, please let me know. Sincerely, Erika Z. Jones, Chief Counsel |
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ID: nht89-2.24OpenTYPE: INTERPRETATION-NHTSA DATE: 06/29/89 FROM: DAVID W. RANEY -- ENVIRONMENTAL ACTIVITIES MANAGER SAAB SCANIA OF AMERICA INC TO: ERIKA Z. JONES -- CHIEF COUNSEL OFFICE OF THE CHIEF COUNSEL NATIONAL HIGHWAY TRAFFIC SAFETY ADMINISTRATION TITLE: NONE ATTACHMT: ATTACHED TO LETTER DATED 10/12/89 FROM STEPHEN WOOD OF NHTSA TO DAVID RANEY OF SAAB; REDBOOK A34, PART 541, 543 TEXT: Dear Ms. Jones: Saab-Scania of America and Saab-Scania AB of Sweden (hereafter collectively referred to as Saab) respectfully request an interpretation of 49 CFR Part 541 -- Federal Motor Vehicle Theft Prevention Standard and 49 CFR Part 543 -- Exemption From Vehicle Th eft Prevention Standard. Our specific questions are as follows: (1) Does Part 543 exempt a manufacturer from marking replacement parts (Part 541.6) on a carline subject to Part 541 when many of the carline replacement parts specified in Part 541.5(a) can also be used to replace parts on the same carline manufactured in earlier model years which were parts-marked in compliance with Part 541? (2) Can a manufacturer of a carline subject to Part 541 and in receipt of a Part 543 exemption for the carline resume vehicle and replacement parts marking if it chooses to discontinue equipping the carline with a Part 543 approved anti-theft device in a future model year? By way of background, the Saab 9000 carline -- introduced in 1986 -- is subject to the Federal Motor Vehicle Theft Prevention Standard. In 1987 and 1988, all Saab 9000 models and replacement parts were marked in compliance with Part 541. For model year 1989 Saab 9000 models, Saab received a Part 543 exemption and discontinued vehicle parts marking. However, Saab has continued to mark the replacement parts specified in Part 541.5 (a). After reviewing the federal regulations, Saab believes that the Part 543 exemption allows it to discontinue marking the replacement parts for the 1989 Saab 9000 carline even though the replacement parts can also be used to replace parts on Saab 9000 mode ls manufactured in previous model years which were parts-marked in compliance with Part 541. Also, Saab believes it retains the right in a future model year to discontinue equipping the Saab 9000 carline with a Part 543 approved anti-theft device for whatever reasons and resume vehicle and replacement parts marking. Saab seeks the NHTSA's concu rrence on both these points. Sincerely, |
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ID: 9503Open Mr. Derrick Barker Dear Mr. Barker: This responds to your letter concerning the buckle release requirement of Federal Motor Vehicle Safety Standard No. 213, "Child Restraint Systems." I apologize for the delay in responding. You asked for the "tensile load requirements for the buckle and tongue." There is no specific requirement in Standard 213 for the tensile force that a child restraint buckle must withstand. Instead, the buckle must maintain its integrity when the child restraint is subjected to a simulated frontal impact at 30 mph with either a six-month-old (17 pounds (lbs.)) or three-year-old (33 lbs.) sized dummy restrained in the car seat. At the conclusion of the simulated impact, the force required to depress the latch button to release the buckle is measured and must be 16 lbs. or less. You also asked for a copy of Procedure D of the American Society for Testing and Materials Standard D756-78. Section S5.4.2 of FMVSS No. 213 sets forth those requirements by making reference to section S4.3(b) of FMVSS No. 209. which, in turn, leads to the reference to Procedure D of ASTM D756-78. The material you requested is enclosed. In addition, you asked for a list of laboratories that test child safety seats and buckles. NHTSA does not endorse particular test laboratories. However, I can provide you with a list of laboratories we are aware of that conduct child restraint compliance tests. There may be other laboratories that can test child safety seats and buckles. Please contact Ms. Deirdre Fujita of my staff if you have further questions. Sincerely, John Womack Acting Chief Counsel Enclosures ref:213 d:4/8/94 |
1994 |
ID: nht75-1.34OpenDATE: 09/11/75 FROM: AUTHOR UNAVAILABLE; F. Berndt; NHTSA TO: The Bendix Corporation TITLE: FMVSS INTERPRETATION TEXT: This responds to your letter of July 14, 1975, requesting an interpretation of the labeling requirements of Federal Motor Vehicle Safety Standard No. 106-74, Brake Hoses, as applied to brake hose end fittings. S5.2.3 of the standard requires (with an exception not relevant here) that one component of a multi-piece end fitting be labeled with certain information. You have pointed out that many end fittings designed for use with nylon brake hose include components identical to those found in fittings used with copper tubing, which is not covered by the standard. Labeling of one of these common components would satisfy the standard. You have interpreted Standard No. 106-74 as permitting an end fitting manufacturer to label his full stock of such components, even though some of them would appear in copper tubing assemblies. Your interpretation is correct. Sincerely, ATTACH. Bendix Heavy Vehicle Systems Group Mark Schwimmer, Attorney -- Office of Chief Counsel, National Highway Traffic Safety Administration July 14, 1975 Subject: Docket 1-5, Notice 15, FMVSS Number 106 BRAKE HOSE IDENTIFICATION Reference: Phone conversation of J. P. Koenig, P. M. Johnston and Mark Schwimmer dated July 10, 1975. Dear Mr. Schwimmer: As per the above-referenced phone conversation, the Bendix Corporation, Heavy Vehicle Systems Group, desires a clarification on the requirements for the labeling of nylon tubing end fittings. A nylon tubing end fitting must be labeled on at least one component of the fitting. Although the components of most nylon tubing end fittings are common with the components of copper tubing end fittings, we interpret that current regulations permit the labeling of an end fitting component which is common to both types of fittings. If correctly interpreted, this practice will result in copper tubing assemblies which are not covered by FMVSS Number 106, but which may consist of an end fitting component which is labeled as an FMVSS Number 106 component. On the other hand, if our interpretation is incorrect, fitting manufacturers will be burdened with the additional inventory and distribution control of handling two end fitting components identical in every respect except labeling. We would appreciate a reply at your earliest convenience. Very truly yours, R. W. Hildebrandt -- Group Director of Engineering |
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.