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: aiam3621OpenMr. Max Peck, Superintendent, Thatcher Unified Schools, District No. 4, P.O. Box 610, Thatcher, AZ 85552; Mr. Max Peck Superintendent Thatcher Unified Schools District No. 4 P.O. Box 610 Thatcher AZ 85552; Dear Mr. Peck: This is in response to your letter of September 30, 1982, enclosing 'petition for exemption...on behalf of Capps and Lancaster Service Center'. The petition concerns a single motor vehicle consisting of the body of a 1974 Dodge school bus which has been removed from its original chassis and attached to a new 1981 International Harvester chassis.; This agency does not regulate the use of motor vehicles. That is matter for State governments. We do enforce the Federal motor vehicle safety standards and grant exemptions as appropriate consistent with our authority.; I regret that the exemption process is not available in your case. Par 555 is intended to cover the future vehicle production of bona fide motor vehicle manufacturers, and not a single conversion, performed in the past, by what appears to be a service garage. Under our regulations, the combination of an old body upon a new chassis results in a new motor vehicle required to meet the motor vehicle safety standards in effect when the chassis was manufactured. Compliance is especially important in this instance because of all the school bus safety standards that have become effective since the bus body was manufactured in 1974, and which affect its structure and that of its seats.; This means that Capps and Lancaster are technically in violation of th National Traffic and Motor Vehicle Safety Act, for which a penalty of up to $1000 may be imposed. We do not intend to pursue this, however, unless other violations come to our attention. However, our Office of Vehicle Safety Compliance will be contacting Capps and Lancaster to make them aware of their responsibilities in order to prevent further violations by that company.; Sincerely, Frank Berndt, Chief Counsel |
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ID: aiam2460OpenMr. David E. Martin, Director, Automotive Safety Engineering, Environmental Activities Staff, General Motors Corporation, General Motors Technical Center, Warren, MI 48090; Mr. David E. Martin Director Automotive Safety Engineering Environmental Activities Staff General Motors Corporation General Motors Technical Center Warren MI 48090; Dear Mr. Martin: This is in response to your November 2, 1976, letter concerning th type of statement regarding Federal Motor Vehicle Safety Standard No. 301-75, *Fuel System Integrity*, that must be included in the incomplete vehicle document supplied by General Motors Corporation along with its Cadillac commercial chassis.; You have essentially repeated the argument of your August 24, 1976 letter to me, in which you disagreed with the interpretation of 49 CFR Part 568, *Vehicles Manufactured in Two or More Stages*, that appeared in my July 20, 1976, letter to you. My letter explained that Part 568 prohibits the use by General Motors of a 'type (iii)' statement with respect to Standard No. 301-75 in the 1977 Cadillac incomplete vehicle document.; Both of your letters emphasize the significant effects that the work o the final-stage manufacturer has on the capability of the completed vehicle to conform to Standard No. 301-75. The NHTSA is mindful of the significance of these effects, and has never suggested that the final-stage manufacturer's work would *not* substantially determine the vehicle's conformity with the standard. Both of your letters erroneously conclude, however, that because the work of the final-stage manufacturer '*will* substantially determine such conformity' (your emphasis), 'the design of such an incomplete vehicle many times *will not substantially determine* conformity...' (your emphasis). This conclusion ignores the interpretation in our letter that, with regard to the vehicles in question, conformity is '*substantially determined by both* the design of the incomplete vehicle and the manner of completion by the final stage manufacturer' (emphasis added). The NHTSA stands by this position.; As you have requested, the letters discussed above have been include in Docket No. EX76-3, Notice 2.; Sincerely, Frank A. Berndt, Acting Chief Counsel |
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ID: aiam2030OpenMr. Robert L. Hunt, Zimmer Homes Corporation, 777 S.W. 12th Avenue, P.O. Box 2127, Pompano Beach, FL 33061; Mr. Robert L. Hunt Zimmer Homes Corporation 777 S.W. 12th Avenue P.O. Box 2127 Pompano Beach FL 33061; Dear Mr. Hunt: This is in response to your letter of August 15, 1975, concerning tir recordkeeping, and in confirmation of your telephone conversation with Mr. Schwartz of this office.; Section 574.10 of 49 CFR Part 574, Tire Identification an Recordkeeping, requires a motor vehicle manufacturer, or its designee, to maintain a record of the tires on each vehicle shipped to a distributor or dealer and the name and address of the first purchaser for purposes other than resale. This record must be kept for at least three years.; I have enclosed a copy of the regulation for your information. Sincerely, Frank A. Berndt, Acting Chief Counsel |
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ID: aiam4808OpenStanley S. Zinner, Esq. Greene & Zinner, P.C. 202 Mamaroneck Avenue White Plains, NY 10601; Stanley S. Zinner Esq. Greene & Zinner P.C. 202 Mamaroneck Avenue White Plains NY 10601; "Re: FMVSS No. 123 Dear Mr. Zinner: This is in reply to your FAX lette of December 4, l990, requesting an interpretation of section S5.2.4 of 49 CFR 571.123 Motor Vehicle Safety Standard No. 123 Motorcycle Controls and Displays. Specifically, you wish an opinion 'as to the meaning, purpose, and intent' of that section. Section S5.2.4 Stands states that 'A stand shall fold rearward and upward if it contacts the ground when the motorcycle is moving forward.' As Taylor Vinson of this Office explained to you, this requirement was one of the original provisions in Standard No. 123 when it became effective in l974. However, unlike many other requirements in the standard, it was both proposed and adopted without any discussion of its meaning, purpose, and intent in the preambles to both these rulemaking actions other than the bare remark that the notices contained a requirement for stands. Furthermore, in the l6 years that the requirement has been in effect, the agency does not appear to have issued a single legal opinion relating to section S5.2.4. However, the agency has issued two interpretations of section S5.2.5 which we believe are relevant to an understanding of S5.2.4. In pertinent part, S5.2.5 Footrests states that 'Each footrest for a passenger other than an operator shall fold rearward and upward when not in use.' In a letter of February 16, l982, to American Honda Motor Co., Inc., with respect to a proposed footboard design, the then Chief Counsel commented that 'We consider that the purpose of S5.2.5 is to prevent accidents caused by rigid footrests contacting the ground in a banking turn.' In a letter of October 26, l973, also to American Honda, the then Assistant Chief Counsel commented that S5.2.5 did not require automatic folding but only the direction in which the footrests shall retract 'so that if they are inadvertently left down when not in use they will fold rearward and upward should they hit an obstacle while the motorcycle is travelling forward.' I enclose a copy of each of these letters for your information. The meaning of S5.2.4 is, we believe, clear and unambiguous: if a stand is left down, it shall fold rearward and upward if it contacts the ground (which includes the roadway) while the motorcycle is moving forward. Because both sections S5.2.4 and S5.2.5 require motorcycle equipment 'to fold rearward and upward', we further believe that the purpose and intent of both sections are the same, and that S5.2.4 could be substituted for S5.2.5 in the sentences of the two letters quoted in the preceding paragraph. I hope that this is responsive to your request. Sincerely, Paul Jackson Rice Chief Counsel Enclosures"; |
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ID: aiam2525OpenMr. Sergio Campanini, Vice President and General Manager, The Berg Manufacturing Company, Iola, KS 66749; Mr. Sergio Campanini Vice President and General Manager The Berg Manufacturing Company Iola KS 66749; Dear Mr. Campanini: This responds to Berg Manufacturing Company's February 9, 1977, reques for confirmation that the emergency and parking brake requirements for trailers contained in Standard No. 121, *Air Brake Systems*, would be satisfied by use of an emergency relay valve (ERV) that, upon a single failure in the service brake system upstream from the ERV, automatically directs the application of service brake air through the antilock valve to service brake chambers in proportion to the amount of air loss being experienced. While parking brake force is supplied first by service brake air and subsequently by means of spring brakes, the spring brake force is not utilized until service brake air pressure is lost in the service brake chamber. This occurs because the spring brakes are held off directly by service reservoir air pressure without provision of an isolated reservoir, controlled by a separate valve that directs spring brake application in response to loss of air pressure in the supply line.; From your description, it does not appear that the system complies wit S5.2.1.1 of Standard No. 121. Section S5.2.1.1 specifies that a reservoir shall be provided on a trailer that is capable of releasing the vehicle's parking brakes at least once and that is 'unaffected by loss of air pressure in the service brake system.' This requirement has been interpreted to mean that a single failure of the service brake system would not result in loss of the isolated air supply. A copy of this interpretation is enclosed for your information. It appears that a single failure of the service brake reservoir in the system you describe would result in the loss of the isolated air required by S5.2.1.1.; In other respects the system you describe does not appear to violat the requirements of Standard No. 121. The use of service air pressure to actuate the parking brakes has been used in certain bus applications and is permissible as long as a source of energy to apply the parking brakes is usable at all times and is unaffected by any single failure in the service brake system.; Sincerely, Frank Berndt, Acting Chief Counsel |
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ID: aiam0518OpenMr. T. A. Branson, Ambassador Trailers, P. O. Box 2522, Muscle Shoals, Al, 35660; Mr. T. A. Branson Ambassador Trailers P. O. Box 2522 Muscle Shoals Al 35660; Dear Mr. Branson: This is in reply to your letter of November 4, 1971, to the Departmen of Transportation, concerning lighting requirements on your boat trailers.; A copy of Federal Motor Vehicle Safety Standard No. 108, 'Lamps Reflective Devices and Associated Equipment' is enclosed for your information. The location of the lamps and reflectors shown on your drawing appears to meet the requirements of Standard No. 108, providing they are mounted to meet the height requirements.; Since the width of your trailer is more than 80 inches, front and rea clearance lamps and rear identification lamps are also required as specified in Table I and located as specified in Table II. Combination front and rear clearance lamps are allowed in paragraph S4.1.1.9.; There are no other requirements for trailers specified in the Federa Motor Vehicle Safety Standards.; Sincerely, E. T. Driver, Director, Office of Operating Systems, Moto Vehicle Programs; |
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ID: aiam2175OpenMr. R. D. Coughlin, Vice President, Rol'on America, Inc., Melbourne, FL 32901; Mr. R. D. Coughlin Vice President Rol'on America Inc. Melbourne FL 32901; Dear Mr. Coughlin: This is in response to your letter of December 10, 1975, regarding th applicability of existing Federal regulations to the manufacture of 'Helmate.'; At the present time, there is no regulation pertaining directly to th type of helmet accessory your corporation produces. The general regulation concerning motorcycle helmets is 49 CFR S 571.218, Motor Vehicle Safety Standard No. 218, *Motorcycle Helmets*. This standard establishes minimum performance requirements for helmets designed for use by motorcyclists and other motor vehicle users.; If a manufacturer, distributor, dealer, or motor vehicle repai business were to install 'Helmates' on helmets, the helmets would have to remain in conformity with the requirements of Standard 218. However, persons other than manufacturers, distributors, dealers, and repair businesses may modify products, after purchase by a user, without regard to the requirements of a Federal safety regulation. Thus, if 'Helmate' is mounted on the helmet by an ordinary consumer, safety Standard 218 is inapplicable.; There is some question as to whether motorcycle helmets will still mee the performance requirements of Standard 218, after the 3/8 inch hole required to mount the 'Helmate' is drilled. If it becomes apparent that installing 'Helmate' type helmet accessories causes the performance level of helmets to drop below the requirements of Standard 218, the NHTSA might find it necessary to enact regulations to rectify the situation. Our main concern is to assure that motorcycle helmets afford riders the protection and safety needed.; If I can be of any further assistance, please feel free to write. Yours truly, Richard B. Dyson, Assistant Chief Counsel |
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ID: aiam0148OpenMr. R. Debesson, European Tire and Rim Technical Organisation, 49, Rue Barathon, 49, 03 - Montlucon, France; Mr. R. Debesson European Tire and Rim Technical Organisation 49 Rue Barathon 49 03 - Montlucon France; Dear Mr. Debesson: This is in reply to your letter of January 21, 1969 requesting the 'actual state of affairs' concerning State requiring a V-1 marking on tires. #You are correct in your understanding that the Federal tire standard (No. 109)(sic) preempts or supersedes any State regulation applicable to the same aspect of performance. The Federal tire standard does not require tires to be marked with the 'V-1' symbol. H wever(sic), it does not prohibit such marking. Our understanding is that American Tire manufacturers have continued marking their product with 'V-1' symbol although not required to do so by the Federal standard. #Sincerely, Robert M. O'Mahoney, Assistant Chief Counsel for Regulations; |
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ID: aiam1309OpenMr. Ralph J. Kalberlon, Executive Vice President, Missouri Automobile Dealers Assoc., 205 East Capitol Avenue, Jefferson City, MO 65101; Mr. Ralph J. Kalberlon Executive Vice President Missouri Automobile Dealers Assoc. 205 East Capitol Avenue Jefferson City MO 65101; Dear Mr. Kalberlon: This is in reply to your letter of October 10, 1973, concerning th legality of disconnecting seat belt interlocks.; The interlock is a required item of safety equipment that must b operable on any new car when it is sold or offered for sale, pursuant to section 108(a)(1) of the National Traffic and Motor Vehicle Safety Act. After an interlock equipped car is sold, however, the purchaser may disconnect the interlock, without violating the Act, by virtue of section 108(b)(1), which exempts transactions after the first purchase of the vehicle.; If a dealer offers to disconnect an interlock as an inducement to th sale of the vehicle, it is our opinion that a violation of the act occurs even though the actual disconnection may take place after delivery of the vehicle. If, on the other hand, the subject of the interlock is not discussed during the sale and the buyer subsequently requests disconnection on the basis of his experience with the vehicle, the dealer would not violate the Act if he disconnected the interlock.; Although a dealer does not violate the act by suggesting that the buye go somewhere else to have the interlock disconnected, I am sure you appreciate the troublesome consequences such advice may bring for the buyer if the resulting disconnection is carelessly performed.; Yours truly, Richard B. Dyson, Assistant Chief Counsel |
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ID: aiam3334OpenMr. R. H. Snyder, Vice President, Tire Technology, Uniroyal Tire Company, 6600 East Jefferson Avenue, Detroit, MI 48232; Mr. R. H. Snyder Vice President Tire Technology Uniroyal Tire Company 6600 East Jefferson Avenue Detroit MI 48232; Dear Mr. Synder: This is in response to your letter of August 14, 1980, requestin interpretation of the Uniform Tire Quality Grading (UTQG) Standards (49 CFR S 575.104) with regard to the assignment of treadwear grades. You report that Uniroyal has encountered variations in treadwear test data derived from UTQG tests conducted by different testing organizations. You ask whether a tire manufacturer is obligated under the UTQG treadwear grading procedure to base its grades on those test results which produce the lowest treadwear grade, or may use any available test data as the basis for grade assignment.; Uniform Tire Quality Grading, as with other National Highway Traffi Safety Administration (NHTSA) regulations, involves a self-certification process in which manufacturers bear the primary responsibility for assuring that their products conform to required levels of performance, in this case the levels represented by their assigned grades. NHTSA's Office of Vehicle Safety Compliance (OVSC) conducts testing to verify that various tires actually provide levels of performance consistent with their grades. When OVSC testing produces results at variance with assigned grades, the manufacturer involved is given an opportunity to provide justification for its grade assignments.; In determining that a product achieves a particular level o performance under the UTQG procedures, a manufacturer may exercise a considerable degree of discretion as to the amount of testing necessary to assure that its conclusions regarding compliance will withstand NHTSA scrutiny. In evaluating the performance of a product, NHTSA does not require that a manufacturer base its judgment on any particular piece of test data or on all available data. In fact, a manufacturer may disregard data from a particular source entirely, if the manufacturer can establish that other data provides a reasonable basis for grading.; However, a manufacturer cannot establish compliance by arbitraril picking and choosing among available data to select results of that test which happened to produce the most favorable result. Data used to establish compliance must be reliable and consistently reproducible, and cannot have been derived through manipulative devices, e.g., abusive driving, or unexacting test procedures. It is the responsibility of the manufacturer to base its conclusions on data demonstrably developed in full conformance with the requirements of the regulation.; NHTSA will provide confidential treatment for your letter of August 14 1980, and the accompanying data.; Sincerely, Frank Berndt, Chief Counsel |
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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.