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: aiam1338OpenMr. W. R. Nelson, Chief of Police, City of San Marcos, P.O. Box 725, San Marcos, TX 78666; Mr. W. R. Nelson Chief of Police City of San Marcos P.O. Box 725 San Marcos TX 78666; Dear Mr. Nelson: This is in reply to your letter of November 14, 1973, concerning th permissibility of installing trailer hitches which prevent the proper function of a vehicle's shock absorbing bumper device.; The attachment of trailer hitches to motor vehicle bumpers will no constitute a violation of any Federal motor vehicle safety standard. The testing requirements of Standard No. 215, which are here applicable, specify that trailer hitches are to be removed prior to testing for compliance. Thus, it is only necessary that the vehicle comply with the regulation when the trailer hitch is not attached. Further, the requirements of the standard do not apply after the first purchase of the vehicle for purposes other than resale, which removes the welding company and the vehicle owner from the standard's coverage once the initial sale has occurred.; Thank you for your inquiry. Yours truly, Richard B. Dyson, Assistant Chief Counsel |
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ID: aiam3305OpenMr. J. Bill Simpson, Simpson Sports, 22630 South Normandie Avenue, Torrance, CA 90502; Mr. J. Bill Simpson Simpson Sports 22630 South Normandie Avenue Torrance CA 90502; Dear Mr. Simpson: This responds to your May, 1980, letter asking whether the Departmen of Transportation preempts State approval programs designed to enforce State standards on equipment regulated by Federal safety standards. In a subsequent conversation with Roger Tilton of my staff, you indicated that several States require you to obtain advance approval from them prior to sale of your motorcycle helmets. You further stated that each of these advance approvals can be very costly.; The National Traffic and Motor Vehicle Safety Act of 1966 (the Act) (1 U.S.C. 138 *et* *seq*.) in section 1392(d) preempts States from having any safety standard applicable to the same aspect of performance as a Federal standard unless the State standard imposes a higher level of performance and applies only to vehicles or equipment purchased for the State's own use. The Act is silent with respect to the preemption of State enforcement procedures, such as approval schemes that require State permission prior to the sale of vehicles or equipment in their jurisdictions.; We note that the issue of advance approval schemes was litigated i *Truck Safety Equipment Inst. v. Kane*, 466 F.Supp. 1242 (D.C., Pa. 1979). In that case (copy enclosed) the court held that a State advance approval scheme was preempted by the Act. We suggest that you bring this case to the attention of the appropriate officials in the States in question. If either you or officials from those States have further questions, you can contact Mr. Tilton at 202-426-9511.; Sincerely, Frank Berndt, Chief Counsel |
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ID: aiam3610OpenMr. Darnley M. Howard, Director, Office of Safety and Health, United States Postal Service, 475 L'Enfant Plaza, S.W., Washington, DC 20260; Mr. Darnley M. Howard Director Office of Safety and Health United States Postal Service 475 L'Enfant Plaza S.W. Washington DC 20260; Dear Mr. Howard: This responds to your August 18 letter to Roger Fairchild of thi office, regarding the use of cross-view mirrors on certain Postal Service vehicles. These mirrors are convex and have a non-uniform radius of curvature. They would be used to assist drivers in viewing the area immediately in front of the vehicle.; Federal Motor Vehicle Safety Standard No. 111 sets forth rear vie mirror requirements for new motor vehicles. Vehicles such as Postal Service trucks are required to comply with one of three specified alternative sets of requirements for mirror systems. The first alternative requires a plane inside mirror providing a specified field of view and a plane exterior driver side mirror, also providing a specified field of view. The second alternative is the same as the first, except that it permits the interior mirror to have a more narrow field of view as long as the vehicle also uses an exterior mirror on the passenger side. The third alternative requires two plane exterior mirrors of at least 19.5 square inches surface area each, with one placed on the driver's side and the other on the passenger's side of the vehicle.; The agency has taken the position that mirrors used on a vehicle i addition to the required mirrors are not subject to any requirements of FMVSS 111. If the cross-view mirrors you wish to use would supplement mirrors which fully comply with one of the alternatives in the standard, the installation of the cross-view mirrors on new Postal Service trucks is in no way prohibited by our standard.; Further, our requirements do not apply to aftermarket modifications t the original equipment mirror system, when those modifications are performed by the vehicle owner. Modifications to the required system would be deemed unlawful only if done by vehicle manufacturers, distributors, dealers, or motor vehicle repair businesses. Thus, the use of the cross-view mirrors is permissible in any case, so long as one of these designated businesses does not perform the modification. However, we recommend that the cross-view mirror be used in addition to the original equipment mirrors, and not as a substitute for those mirrors. Based on our experience with non-uniform radius mirrors, these mirrors should not be used when the vehicle is in motion, since the mirror produces an image which can distort distances. Rather, the mirror should be used to detect people in front of the vehicle while the vehicle is stopped.; NHTSA would appreciate the opportunity to review the results of you test program once it is completed. If we can be of assistance to you in evaluating the mirrors, please feel free to contact us.; Sincerely, Frank Berndt, Chief Counsel |
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ID: aiam2902OpenMr. Walter J. Kulpa, Yankee Metal Products Corp., Norwalk, CT 06852; Mr. Walter J. Kulpa Yankee Metal Products Corp. Norwalk CT 06852; Dear Mr. Kulpa:#This is in response to your letter of September 18 1978, requesting a clarification of Federal Motor Vehicle Safety Standard No. 101-80, *Controls and Displays*. The National Highway Traffic Safety Administration concurs in your interpretation of S5.3.1 that any hand operated control which is mounted on the steering column does not have to meet the illumination requirements of Column 4 of Table 1.#Sincerely, Joseph J. Levin, Jr., Chief Counsel; |
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ID: aiam3240OpenMr. Bart Achille, National Sales Manager, American Moped Associates, 1852 Langley Avenue, Irvine, California 92714; Mr. Bart Achille National Sales Manager American Moped Associates 1852 Langley Avenue Irvine California 92714; Dear Mr. Achille: This responds to your letter of March 11, 1980, forwarding to Mr Schwartz of my office the proposed vehicle identification number (VIN) scheme for American Moped Associates, and in confirmation of your subsequent telephone conversation with Mr. Schwartz.; Your VIN scheme complies with the requirements of Federal Motor Vehicl Safety Standard No. 115, with the following exceptions. The fourth through eighth characters of the VIN are required by S4.5.2 and Table I of the Standard to encode certain descriptive characteristics of the vehicle. For motorcycles, which include mopeds, this information is (1) type of motorcycle, (2) line, (3) engine type and (4) net brake horsepower. While the information which American Moped Associates proposed to encode in the fourth through eighth characters will undoubtedly be useful to your company, it is not necessary to advise the agency of your internal coding. Further, While much of the information the Standard required to be decoded from these characters is self-evident because of your product line, it is nonetheless necessary to forward this information to the agency as specified in the Standard.; Based on your discussions with Mr. Schwartz, it appears this mayb easily accomplished utilizing essentially the same format as you currently propose. It is my understanding that you no longer intend to encode the color in the fifth position of the VIN, but rather utilize a single 'filler' character such as 'M'. Further, I understand that all your mopeds utilize the same engine and comprise two lines characterized by the number of speeds. Consequently, based on your product line, your submission to the agency might read:; Characters 1-3 LAM: WMI assigned to American Moped Associates. Character 4 (internal use) Character 5 M: Indicates moped type: gasoline, one cylinder, engin with a displacement of_______, net-brake horsepower measured at the crankshaft of __________.; Character 6 (internal use). Character 7 1 indicates one-speed Indian line. 2 indicates two-spee Indian line.; Character 8 (internal use). Character 9 Check digit. Character 10 Model year. Character 11 T: Indicates Taipei plant of manufacture. Y: Indicate Yuanlin plant of manufacture.; Characters 12-17 Sequential number. Please feel free to contact Mr. Schwartz should you have any furthe question on this matter.; Sincerely, Frank Berndt, Chief Counsel |
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ID: aiam4585OpenSamson Helfgott, Esq. Helfgott & Karas, P.C. 60th Floor Empire State Building New York, NY l0ll8-0ll0; Samson Helfgott Esq. Helfgott & Karas P.C. 60th Floor Empire State Building New York NY l0ll8-0ll0; Dear Mr. Helfgott: This is in reply to your letter of January 12, l989 asking whether Federal regulations permit the use of an amber lamp either as original or aftermarket equipment. The lamp would be placed adjacent to the center highmounted stop lamp, but in a separate housing and wholly independent of it. It would be activated when the ignition is turned on, and deactivated whenever the stop lamps are illuminated. The purpose of the amber lamp is to improve conspicuity of the vehicle in order to lessen the braking response time of drivers in vehicles following. Paragraph S4.1.3 of 49 CFR 571.108 Federal Motor Vehicle Safety Standard No. 108 Lamps, Reflective Devices and Associated Equipment allows a supplementary lighting device such as the amber lamp if it does not impair the effectiveness of lighting equipment required by Standard No. 108. The decision regarding impairment is initially that of the manufacturer of the vehicle on which the supplementary device is installed, and which the manufacturer certifies as complying with all applicable Federal safety standards. In this instance you have indicated that the wiring of the amber lamp is independent of the center lamp, and that the amber lamp is inoperative when the stop lamps are on. While your lamp does not appear to impair the effectiveness of the center lamp, you should consider whether your lamp, since it would be a steady-burning amber lamp, might confuse following drivers unused to seeing a steady burning amber lamp on the rear of a vehicle, or because of its brightness. Should the amber lamp create confusion, it may impair the effectiveness of the other rear lamps required by Standard No. 108, each of which (other than the stop lamps) would when in use operate contemporaneously with it, such as an amber turn signal lamp, or a back up lamp. As part of the vehicle manufacturer's certification to Standard No. 108, it must certify that this situation would not occur, if the lamp is to be permissible as an item of original equipment. As an aftermarket device, the amber lamp is not regulated by Standard No. 108, but is subject to the general prohibition of l5 U.S.C. 1397(a)(2)(A) against rendering inoperative, in whole or in part, equipment installed in accordance with a safety standard. The same considerations as discussed above should be taken into consideration when making this determination. In addition, the use of this lamp is subject to local laws. We are not able to advise you as to these laws, and suggest that you consult for an opinion the American Association of Motor Vehicle Administrators, 4600 Wilson Boulevard, Arlington, VA 22203. Sincerely, Erika Z. Jones Chief Counsel; |
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ID: aiam1787OpenMr. Arthur M. Elson,Acme-Hamilton Manufacturing Corporation,P.O. Box 361,Trenton, New Jersey 08603; Mr. Arthur M. Elson Acme-Hamilton Manufacturing Corporation P.O. Box 361 Trenton New Jersey 08603; Dear Mr. Elson:#Please forgive the delay in responding to your lette of october 4, 1974, requesting information on the labeling of air brake hose with you manufacture.#You have correctly interpreted Federal Motor Vehicle Safety Standard No. 106-74,*Brake Hose*, as requiring labeling identifying Acme-Hamilton as the manufacturer of the hose, and not requiring further labeling identifying your customers. You are permitted to label the hose with optional information, such as your customer's name, in addition to that required by S5.2.2 as incorporated in S7.2 of the Standard. To avoid confusion with the required information, however, the optional information must appear on the opposite side if the hose.#Yours truly,Richard B. Dyson,Acting Chief Counsel; |
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ID: aiam0895OpenMr. Edward F. Kearney, Executive Director, National Committee on Uniform Traffic Laws and Ordinances, 1776 Massachusetts Avenue, N.W., Suite 430, Washington, DC 20036; Mr. Edward F. Kearney Executive Director National Committee on Uniform Traffic Laws and Ordinances 1776 Massachusetts Avenue N.W. Suite 430 Washington DC 20036; Dear Mr. Kearney: This is in response to your letter of October 4, 1972, asking, amon other things, whether the National Traffic and Motor Vehicle Safety Act preempts the recent California law requiring motorcycles made on or after January 1, 1975, to be wired so that their headlamps are lit whenever the engines are running. In light of the answer to this question, it is not necessary to deal with the other ones.; It is the opinion of this agency that the California law in question i preempted in accordance with section 103(d) of the Act, 15 U.S.C. 1392(d), and is therefore void. Standard No. 108, 49 CFR S 571.108, establishes requirements for motorcycle headlighting, along with special wiring requirements for motorcycles and other vehicles. It is our position, therefore, that the California requirement is within the scope of the aspects of performance covered by Standard No. 108. Since it is not identical to a Federal requirement, it is rendered void by operation of the Act.; Sincerely, Douglas W. Toms, Administrator |
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ID: aiam2001OpenMr. David E. Hatch, Development Project Director, Product Development Division, Reynolds Metals Company, 5th and Cary Streets, Richmond, VA 23261; Mr. David E. Hatch Development Project Director Product Development Division Reynolds Metals Company 5th and Cary Streets Richmond VA 23261; Dear Mr. Hatch: This is in response to your letter of July 14, 1975, asking whethe recycled replacement bumpers must comply with the requirements of Standard No. 215, *Exterior Protection*, and which States have bumper requirements that exceed the level of performance mandated by the Federal standard.; Standard No. 215 is a motor vehicle safety standard that applies to th performance of bumper systems on cars manufactured after certain dates. The requirements of the standard are not imposed on the manufacturers of the bumper as an item of motor vehicle equipment. It is the manufacturer of the car who must certify the compliance of the bumper system with the provisions of Standard 215. Therefore, the sale of a bumper, as an item of replacement equipment, does not fall within the application of the standard.; Section 108 of the National Traffic and Motor Vehicle Safety Act (Pub L. 89-563), as amended (Pub. L. 93-492), prohibits any manufacturer, distributor, dealer, or motor vehicle repair business from knowingly rendering inoperative any device or element of design installed on or in a motor vehicle or item of motor vehicle equipment in compliance with a safety standard. Thus, even though a recycled bumper is not required to meet the requirements of Standard 215 when it is produced or sold, its installation on a car by one of the above-named persons would invoke the application of section 108 of the Act. As long as a vehicle complies either with the particular safety standard in effect at the time of its manufacture or with the standard in effect at the time the system in question is replaced or altered, no violation of section 108 would have occurred.; The Motor Vehicle Information and Cost Savings Act of 1972 (Pub. L 92-513) directs the National Highway Traffic Safety Administration (NHTSA) to promulgate a Federal bumper standard that will achieve the maximum feasible reduction in costs to consumers who are involved in low speed collisions. Currently, several States have bumper standards that are geared toward the same type of cost reduction. According to section 110 of the Cost Savings Act, States with cost-reduction standards (applying to non-safety-related damage) that were in effect or promulgated by the date of the Act's issuance (October 20, 1972) can retain those standards, to the extent they do not conflict with Standard No. 215, until a Federal cost-reduction bumper standard takes effect. Once the NHTSA enacts such a Federal bumper standard, those bumper standards which are not identical will be preempted.; As far as we know, the only States which currently have bumpe standards imposing requirements different from those contained in Standard 215 are California, Florida, and Georgia.; Sincerely, Frank Berndt, Acting Chief Counsel |
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ID: aiam5394OpenMr. Jerry Steffy Triumph Designs Ltd. Jacknell Road Dodwells Bridge Industrial Estate Hinckley, Leicestershire LE10 3BS England; Mr. Jerry Steffy Triumph Designs Ltd. Jacknell Road Dodwells Bridge Industrial Estate Hinckley Leicestershire LE10 3BS England; "Dear Mr. Steffy: This responds to your request to Mr. David Elias formerly of this office, for an interpretation concerning whether a motorcycle certification label may be placed in a location other than that specified in 49 CFR Part 567, Certification. As explained below, the answer is yes, the agency has permitted an alternative location in certain circumstances. 49 CFR 567.4(e) states that motorcycle certification labels 'shall be affixed to a permanent member of the vehicle as close as is practicable to the intersection of the steering post with the handle bars, in a location such that it is easily readable without moving any part of the vehicle except the steering system.' In your letter, you seem to refer to this intersection as the 'headstock area,' and ask whether the certification label can be placed elsewhere. In an interpretation letter of November 23, 1982, to Suzuki Motor Co., Ltd., (copy enclosed) NHTSA permitted the motorcycle certification label to be placed 'on the down tubes in front of the engine on either the right or left side.' The agency permitted the alternate location because some Suzuki motorcycles were equipped with fairings, obscuring labels placed in the specified location. Your inquiry seems to imply that Triumph's design would cause a certification label placed in the location specified in 567.4(e) to be obscured. If that is the case, please contact Mr. George Shifflett of NHTSA's Office of Vehicle Safety Compliance at (202) 366-5307. NHTSA would be happy to work with you on finding an alternative location for your certification label. I hope this information is helpful. If you have any further questions, please contact Ms. Dorothy Nakama of my staff at (202) 366-2992. Sincerely, John Womack Acting Chief Counsel Enclosure"; |
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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.