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: aiam1785OpenMr. Philip H. Taft, Director, Tire Retreading Institute, 1343 L Street, N.W., Washington, D.C. 20005; Mr. Philip H. Taft Director Tire Retreading Institute 1343 L Street N.W. Washington D.C. 20005; Dear Mr. Taft: This is in reply to your letter of December 20, 1974, to Edwar Wallace, asking that we republish Motor Vehicle Safety Standard No. 117 as one complete document. You point out that there have been several amendments to Standard No. 117, which makes a comprehensive reading of the standard difficult. You ask also that we incorporate directly in any republication the provisions of Standard No. 109 that are presently incorporated by reference, and you point out some errors in the text of the standard.; The complete standard should be republished as a single unit in th forthcoming edition of the *Code of Federal Regulations*, Title 49, Parts 200-999. We expect republication of this volume in the very near future. The errors you mention, i.e., that paragraphs S6.2 and S6.3.1(f) have been superseded and are therefore superfluous, are inconsequential in our view. However, we will defer any decision regarding your request until republication of the complete standard in the *Code of Federal Regulations*. If that version of the standard is not substantially correct in all respects, we will take steps to republish a corrected version.; Yours truly, Richard B. Dyson, Acting Chief Counsel |
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ID: aiam4568OpenMr. Wendell D. Kegg Tire/Wheel Consultants 12190 Hoover Avenue, OH 44685; Mr. Wendell D. Kegg Tire/Wheel Consultants 12190 Hoover Avenue OH 44685; "Dear Mr. Kegg: This responds to your letter seeking an interpretatio of Federal Motor Vehicle Safety Standard No. 110, Tire Selection and Rims. You were uncertain about section S4.3.1's requirements related to the inflation pressure for spare tires specified on vehicle placards. You asked whether a vehicle manufacturer can specify a higher inflation pressure for a spare tire than the maximum inflation pressure molded on the tire's sidewall. As you know, FMVSS 110 sets forth requirements related to vehicle placards in passenger cars. Section S4.3 requires that the placard be 'permanently affixed to the glove compartment door or an equally accessible location' and display the vehicle capacity weight, the designated seating capacity, the vehicle manufacturer's recommended cold tire inflation pressure for maximum loaded weight and, subject to the limitations of S4.3.1, for any other manufacturer-specified vehicle loading condition, and the vehicle manufacturer's recommended tire size designation. FMVSS 110 does not have any provision requiring the inclusion of information on the placard related to spare tires or air pressure related to spare tires. Accordingly, a passenger car manufacturer may, but is not required to, specify information related to spare tires on the placard. In response to your question whether a passenger car manufacturer can specify a higher inflation pressure for a spare tire than the maximum inflation pressure molded on the spare tire's sidewall, section S4.3.1 of FMVSS 110 states that the vehicle placard must not specify an 'inflation pressure other than the maximum permissible inflation pressure' required to be molded on the tire itself by section S4.3 of FMVSS 109, New Pneumatic Tires, unless the alternative inflation pressure satisfies the three conditions set forth in S4.3.1. The first condition requires that the alternative inflation pressure be less than the maximum permissible inflation pressure. The second condition requires that the vehicle loading condition be specified for the alternative reduced pressure. The third condition requires that the tire load rating be specified by an individual manufacturer for the tire size at that inflation pressure that is not less than the vehicle load on the tire for that vehicle loading condition. Accordingly, a vehicle manufacturer could not specify on its placard an inflation pressure that exceeds the maximum permissible inflation pressure. I am enclosing a December 13, 1984 letter to Mr. Alberto Negro of Fiat, which explains the agency's position concerning a manufacturer's specification on the placard of an inflation pressure that exceeds the maximum inflation pressure molded on the tire. As that letter indicates, a manufacturer would have to meet each of the conditions specified in section S4.3.1, including that the alternative inflation pressure must be less than the maximum permissible inflation pressure. Because spare tires are subject to these requirements like any other pneumatic tire, a vehicle manufacturer could not specify a higher inflation pressure for a spare tire than the maximum inflation pressure molded on that tire. If you have any further questions or need additional information on this subject, please feel free to contact Marvin Shaw of my staff at this address or by telephone at (202) 366-2992. Sincerely, Erika Z. Jones Chief Counsel Enclosure"; |
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ID: aiam1290OpenMr. Franklin J. Kivel, 1100 City National Bank Tower, Oklahoma City, OK 73102; Mr. Franklin J. Kivel 1100 City National Bank Tower Oklahoma City OK 73102; Dear Mr. Kivel: Your request for information on odometer laws was forwarded to us b the Office of Consumer Affairs.; There is at this time no Federal law that requires odometers to b sealed. The Motor Vehicle Information and Cost Savings Act, which we administer, prohibits altering, resetting, or disconnecting odometers except for lawful repair. It does not, however, require sealed odometers and automobile manufacturers do not normally seal odometer units. Some manufacturers incoporate (sic) anti-tampering features which stain the odometer drum with ink or that destroy its gears if an attempt is made to reverse its direction.; The Act does require disclosure of a vehicle's actual and recorde mileage by a seller before its transfer to a buyer. We are presently conducting a study of the Act's effectiveness.; Sincerely, Lawrence R. Schneider, Chief Counsel |
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ID: aiam0878OpenHonorable Douglas W. Toms, Administrator, National Highway Traffic Safety Administration, Department of Transportation, 400 Seventh Street, S. W., Washington, DC 20591; Honorable Douglas W. Toms Administrator National Highway Traffic Safety Administration Department of Transportation 400 Seventh Street S. W. Washington DC 20591; Dear Dr. Toms: We enclose a copy of a Resolution adopted by the 52nd annual conventio of the National Tire Dealers & Retreaders Association, Inc.; Could you inform us, please, of the consideration being given by you Administration to the NTDRA's proposal? Do you think their plan might represent a reasonable compromise between the public interest in tire safety and the obvious interest of tire dealers in lessening their burden of wholly uncompensated Federal paperwork?; With best wishes, Sincerely, Chester H. Smith, Staff Director - General Counsel, Unite States Senate, Select Committee on Small Business; |
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ID: aiam2845OpenMr. Martin P. Ronsen, President, Euro-Tire, Inc., 1275 Bloomfield Avenue, Fairfield, NJ 07006; Mr. Martin P. Ronsen President Euro-Tire Inc. 1275 Bloomfield Avenue Fairfield NJ 07006; Dear Mr. Ronsen: This responds to your June 1, 1978, letter asking whether it i acceptable for you as a tire distributor to use your own tire registration form as long as it complies with the requirements of Part 574, *Tire Identification and Recordkeeping*.; Part 574.7 of the Code of Federal Regulations (CFR) provides that dealer of tires may supply his own form on which to record information specified in paragraphs (a)(1), (a)(2) and (a)(3), as long as the form contains the required information, conforms in size and is similar in format to the 'Universal Format' form set forth in Figure 3 of that part. The form designed by Euro-Tire appears to meet the requirements of Part 574. Accordingly, it is acceptable for use in fulfilling the tire recordkeeping requirements.; Sincerely, Joseph J. Levin, Jr., Chief Counsel |
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ID: aiam3757OpenMr. Karl-Heinz Ziwicka, Manager, Safety & Emission Control Engineering, BMW of North America, Inc., Montvale, NJ 07645; Mr. Karl-Heinz Ziwicka Manager Safety & Emission Control Engineering BMW of North America Inc. Montvale NJ 07645; Dear Mr. Ziwicka: This is in reply to your letter of August 4, 1983, to Mr. Vinson o this office asking for reconsideration of our December 8, 1982, letter in which we stated that Motor Vehicle Safety Standard No. 108 prohibits the use of glass or plastic shields in front of motorcycle headlamps. You have pointed out that this appears to reverse a previous interpretation issued by this office on March 15, 1978, in which we concluded that such covers were not precluded.; As is well known, SAE Standard J580 *Sealed Beam Headlamp Assembly precludes the use of covers in front of headlamps in use. Because Standard No. 108 allows installation on motorcycles of half of a passenger car sealed beam headlighting system (principally because SAE J584 allows use of headlamps meeting SAE J579 *Sealed Beam Headlamp Units*), the 1982 interpretation applied the prohibition against covers to all sealed beam headlamps, even those used on motorcycles. With respect to unsealed lamps, the agency cited paragraph S4.1.3, the prohibition against installation of additional equipment impairing the effectiveness of required lighting equipment, and concluded that the possibility of deterioration of light output through cracked or discolored covers precluded covers over nonsealed lamps. On the other hand, the 1978 interpretation concluded that, since the cross referenced J579 did not itself reference J580, the prohibition did not apply.; We have reviewed this matter and have concluded that headlamp cover for motorcycles are not *per se* prohibited by Standard No. 108. As the 1978 interpretation implies, and as you make explicit, the only standard Table III directly incorporates for motorcycles headlamps is J584, whereas J580 is one of several standards directly incorporated for headlamps on four-wheeled vehicles. Nevertheless, we still conclude that these covers are prohibited if they impair the effectiveness of the headlamp.; If, for example, the angle of the cover is so extreme that headlam 'effectiveness' is 'impaired' because of deterioration of the beam, then the manufacturer may wish to remove the shield or redesign it. If, as another example, a plastic cover is intended and a manufacturer has knowledge that it is susceptible to accelerated hazing or cracking, that manufacturer should not use a cover manufactured of this plastic.; In summary, this letter modifies both our 1978 and 1982 opinions b concluding that headlamp covers for motorcycles are permissible if they will not impair the effectiveness of the headlamp.; The agency is reviewing this subject to determine if rulemaking i advisable to prohibit covers of any sort over motorcycle headlamps, similar to the prohibition against such covers on four-wheeled motor vehicles.; Sincerely, Frank Berndt, Chief Counsel |
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ID: aiam4092OpenMr. Carl R. Walker, Manager, Technical Sales and Service, P.T. Brake Lining Company, Inc., P.O. Box 329, Lawrence, MA 01842; Mr. Carl R. Walker Manager Technical Sales and Service P.T. Brake Lining Company Inc. P.O. Box 329 Lawrence MA 01842; Dear Mr. Walker: This responds to your letter addressed to Mr. Richard Radlinski concerning a statement by International Transquip alleging that the National Highway Traffic Safety Administration (NHTSA) and the Bureau of Motor Carrier Safety (BMCS) 'agree' that the Mini-Max brake system produced by that company complies with Federal standards. You noted that International Transquip has referenced a June 6, 1984 letter from BMCS.; NHTSA does not provide approvals of motor vehicles or motor vehicl equipment. Under the National Traffic and Motor Vehicle Safety Act, it is the responsibility of the manufacturer to ensure that its vehicles or equipment complies (sic) with applicable safety standards. I would emphasize that NHTSA has not issued any statement that could be read as 'agreement' that the Mini-Max brake complies with FMVSS No. 121.; We are enclosing a copy of a letter addressed to Navistar whic discusses NHTSA's position concerning the June 6, 1984 letter from BMCS. The letter also notes that the California Highway Patrol (CHP) has raised a number of issues relating to the compliance and overall safety of Mini-Max brakes in connection with a petition for rulemaking, and that International Transquip has submitted comments on CHP's analysis. We have enclosed for your information a notice granting the CHP petition and two related interpretation letters, to International Transquip and the New Jersey Division of Motor Vehicles. The CHP and Mini-Max submissions have been placed in the Petitions for Rulemaking (PRM) Docket for FMVSS No. 121. If you desire copies of those submissions, please contact: Docket Section, National Highway Traffic Safety Administration, Room 5109, 400 Seventh Street, S.W., Washington, DC 20590 (202-426-2768).; Sincerely, Erika Z. Jones, Chief Counsel |
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ID: aiam4138OpenMs. Cheryl Smith, B.B. Foreign Car Sales, 2983 El Camino Real, Santa Clara, CA 95051; Ms. Cheryl Smith B.B. Foreign Car Sales 2983 El Camino Real Santa Clara CA 95051; Dear Ms. Smith: Thank you for your recent telephone call requesting information on th Federal odometer law. Enclosed is a copy of Title IV of the Motor Vehicle Information and Cost Savings Act (15 U.S.C. 1981 *et seq.*), which is the pertinent statute, as well as regulations prescribing odometer disclosure requirements (49 CFR Part 580), and a fact sheet that we have prepared on this subject.; Section 580.4 of the regulations prescribes the contents of th disclosure statement which must be furnished by the buyer to the seller at the time ownership of a motor vehicle is transferred. This includes the odometer reading at the time of transfer, the date of transfer, the name, address, and signature of both the buyer and seller, and a statement indicating either that the odometer reflects actual miles driven or that the true mileage is unknown.; You asked whether it is necessary for odometer disclosure statements t be furnished when ownership of a new vehicle is transferred. Under section 580.5(b) of the regulations, the odometer reading of a new vehicle need not be disclosed prior to its first transfer for any purposes other than resale. This exemption does not apply when ownership of the vehicle is transferred to the first retail customer. It is consequently necessary for your dealership to furnish odometer disclosure statements in transactions of this nature. As provided in section 580.7 of the regulations, it must furthermore retain a copy of these statements for a period of four years at its principal place of business in a manner that permits systematic retrieval.; I hope this information has been helpful. If we can be of any furthe assistance, please feel free to contact us again.; Sincerely, David W. Allen, Assistant Chief Counsel |
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ID: aiam3307OpenMr. Roy Knoedler, Senior Industrial Designer, Cosco, 2525 State Street, Columbus, IN 47201; Mr. Roy Knoedler Senior Industrial Designer Cosco 2525 State Street Columbus IN 47201; Dear Mr. Knoedler: This responds to your letter of April 17, 1980, to Mr. Vladisla Radovich concerning Standard No. 213, *Child Restraint Systems*. Your letter was referred to my office for reply.; You asked if a child restraint has 'shoulder straps that attach to shield or barrier, and these straps in turn are connected to a crotch strap in continuous loop by way of going behind and then coming up from below the shell, would these belts then be considered an integral part of the shield and would attaching the crotch strap to the shield by means of a buckle be allowed?'; Standard No. 213, *Child Restraint Systems*, is intended to address among other things, the problem of misuse of child restraints. The principal misuse involves the failure to attach buckles and latches. To ensure that children using child restraints are afforded protection notwithstanding such misuse, the standard specifies that the belts are to be attached to restraining shield during testing only if they are an integral part of the shield. Webster's New Collegiate Dictionary (1977) defines 'integral' as meaning 'formed as a unit with another part.' Attachment of belts that are integral parts is permitted since they are intended to remain attached whether or not the restraint is in use and thus are not subject to the type of misuse described above. The crotch strap you describe is not an integral part of the movable shield. The movable shield is a complete unit by itself. The crotch strap is a separate device that must be manually connected to the shield every time the unit is used.; You also asked if belts that must be adjusted to fit a child ar prohibited by the standard. The standard does not prohibit adjustable belts. Section 5.4.2 of the standard does, however, establish requirements for any belt adjustment hardware used in the restraint.; Finally, you asked whether a surface, which is contactable by the tes dummy head, that 'is not a rigid surface but instead is a soft flexible part or sling type of surface' would have to be covered with energy absorbing foam. Section 5.2.3.1 provides that each child restraint system, other than a harness, which is recommended for use by children weighing less than 20 pounds must comply with the performance requirements of section 5.2.3.2. Section 5.2.3.2 provides that 'Each surface, except for protusions (sic) that comply with S5.2.4, which is contactable by the dummy head when the system is tested in accordance with S6.1 shall be covered with slow-recovery, energy- absorbing material' of specified characteristics. The requirement for padding applies to any surface contactable by the test dummy's head, regardless of whether the surface is rigid or flexible. If the contactable surface is made of a flexible material that would meet the thickness and performance requirements for energy-absorbing padding set in section 5.2.3.2(a) and (b), the surface would not have to have a separate layer of energy-absorbing padding placed on top of it.; If you have any additional questions, please let me know. Sincerely, Frank Berndt, Chief Counsel |
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ID: aiam5379OpenThe Honorable Mike Parker House of Representatives Washington, DC 20515-2404; The Honorable Mike Parker House of Representatives Washington DC 20515-2404; "Dear Mr. Parker: Thank you for your letter on behalf of you constituent, Mr. George Duke of the Jones County School District, concerning your constituent's desire to install television monitors in school buses to air 'drug-free videos.' You asked whether the installation would be consistent with our school bus regulations. I am pleased to explain our school bus regulations. By way of background, the National Traffic and Motor Vehicle Safety Act of 1966 (Safety Act) authorizes the National Highway Traffic Safety Administration (NHTSA) to issue Federal motor vehicle safety standards (FMVSS) for new motor vehicles, including school buses. Under the authority of the Safety Act, NHTSA issued FMVSS No. 222, 'School Bus Passenger Seating and Crash Protection.' The standard has head impact protection requirements that require the area around a school bus passenger to be free of surfaces that could injure the child in a crash. All new school buses must be certified as complying with FMVSS No. 222. Our regulations do not prohibit Jones County from installing the video equipment in their school buses. Since the FMVSS only apply to new school buses, we do not require existing school buses to continue to meet FMVSS No. 222. Further, NHTSA does not regulate in any manner how individual owners choose to modify their own vehicles. Thus, the Jones County School District may install the television monitors in its school buses without regard to whether the head impact protection requirements of FMVSS No. 222 are maintained. However, we would urge Jones County to install the television monitors safely. Standard No. 222 requires large school buses to provide passenger crash protection through a concept called 'compartmentalization.' Compartmentalization entails improving the interior of the school bus with protective seat backs, additional seat padding, and better seat spacing and performance. These interior features are intended to keep occupants in their seating area and to ensure that the seating area is free from harmful structures. To protect school bus passengers, we suggest to Jones County that any video equipment installed on a school bus should be outside of an area that a school bus passenger might impact in a crash. Further, the equipment should be installed so that it does not become unsecured, especially during a crash where any projectile can be very dangerous to the vehicle occupants. We also note that the Safety Act limits how certain commercial businesses may modify new or existing school buses. Section 108(a)(2)(A) of the Safety Act prohibits manufacturers, distributors, dealers, and motor vehicle repair businesses from knowingly rendering inoperative any safety device or element of design installed on or in a motor vehicle or item of equipment in compliance with any FMVSS. If any of these parties installed the video equipment in a manner that rendered inoperative the compliance of the school bus with FMVSS No. 222, a possible violation of 108(a)(2)(A) could result. The 'render inoperative' provision of section 108(a)(2)(A) does not apply to owners modifying their own vehicles. Thus, the Jones County School District, the owner of the school buses, could install the equipment itself in its own shops without violating this or any other provision of the Safety Act. As mentioned above, NHTSA urges the school district to ensure that the equipment does not degrade the safety of the school buses, particularly with regard to the head impact protection provided by the buses. I hope this information will be helpful to you in responding to your constituent. If you or your constituent have any further questions, please feel free to contact John Womack, Acting Chief Counsel, at this address or at (202) 366-9511. Sincerely, Christopher A. Hart Acting Administrator"; |
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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.