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
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ID: aiam0273OpenMr. Angelo J. Introvigne, Chief Engineer, Cole-Hersee Company, 20 Old Colony Avenue, South Boston, MA 02127; Mr. Angelo J. Introvigne Chief Engineer Cole-Hersee Company 20 Old Colony Avenue South Boston MA 02127; Re: Federal Motor Vehicle Safety Standard No. 101, Control Location Identification, and *Illumination*#Dear Mr. Introvigne:#This is in reply to your letter of September 2 asking whether a contradiction exists in paragraph S4.3 of Standard No. 101. You ask, in essence, whether the requirement in paragraph S4.3 that an illumination adjustment control be provided with an 'off' position contradicts the requirement in the same paragraph that control identification 'shall be illuminated . . . whenever the headlamps are activated.'#It is true that activation of the headlamps will not simultaneously activate control identification illumination if the illumination switch is in the 'off' position. The intent of S4.3 is that control identification shall be illuminated whenever the headlamps are activated and the illumination adjustment control is in a position other than 'off.'#Sincerely, Lawrence R. Schneider, Chief Counsel; |
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ID: aiam2521OpenMr. Jack Gromer, Vice President - Engineering, 5990 N. Washington Street, Denver, CO 80216; Mr. Jack Gromer Vice President - Engineering 5990 N. Washington Street Denver CO 80216; Dear Mr. Gromer: This responds to Timpte's January 11, 1977, question whether NHTS regulations prohibit sale and delivery of a trailer to the first purchaser equipped with two used tires in place of the eight tires that are specified for the vehicle and which would form the basis of certification under Part 567, *Certification* and the basis of compliance with Standard No. 120, *Tire Selection and Rims for Vehicles Other Than Passenger Cars*.; As you are aware, Part 567 of our regulations requires a statement b the vehicle manufacturer of the gross axle weight rating (GAWR) for each axle on any motor vehicle it manufactures (S 567.4(g)(4)). The term 'GAWR' is defined in S 571.3 of our regulations as the value specified by the manufacturer as the load-carrying capacity of the axle system, measured at the tire- ground interfaces. This clearly means that the tires and wheels on an axle must be taken into account in assigning a GAWR value for certification purposes.; Standard No. 120 specifies that 'each vehicle . . . shall be equippe with tires that meet specified requirements ' (S5.1.1) but makes provision for the installation of used tires owned by the purchaser if the maximum load ratings of the tires on an axle system are at least equal to the GAWR assigned to the axle system by the vehicle manufacturer (S5.1.3). Section S5.1.3 reflects the agency's view that existing commercial practices for the delivery of vehicles with safe used tires has not created a significant safety problem to date.; In recognition of varying commercial practices for the delivery o vehicles, the agency has interpreted S5.1.1 of Standard No. 120 to prohibit the installation of tires that do not meet certain performance requirements, but not as a requirement that tires be fitted to every axle of a vehicle prior to certification and sale. A copy of this interpretation is enclosed for your information. The interpretation makes clear that, while the agency interprets Standard No. 120 (and by implication Part 567) to permit the assignment of a GAWR on the basis of tires listed on the certification plate, the assignment of an arbitrarily high (or low) GAWR for purposes such as avoiding a Federal motor vehicle safety standard could constitute a violation of law.; With regard to the practice you describe of delivering an empty ne trailer to the purchaser on fewer tires that (sic) necessary to conform to the GAWR listed on the certification plate and the minimum requirements of S5.1.1 and S5.1.2 of Standard No. 120, the agency interprets its motor vehicle safety standard and S 567.4(g)(4) to permit such a good faith delivery practice. In the event any pattern of avoidance of Federal requirements becomes apparent, however, the agency would reconsider this interpretation.; Sincerely, Frank Berndt, Acting Chief Counsel |
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ID: aiam2171OpenMr. Robert J. Geurink, 4595 Angelo Drive N.E., Atlanta, GA 30319; Mr. Robert J. Geurink 4595 Angelo Drive N.E. Atlanta GA 30319; Dear Mr. Geurink: This is in reply to your letter of December 29, 1975, to the Departmen concerning 'general policies on recalls and any rules you may have on them.'; From September 9, 1966, when the National Traffic and Motor Vehicl Safety Act was enacted, until December 27, 1974, a manufacturer was required to notify purchasers of the existence of a safety-related defect or a non-compliance with a Federal motor vehicle safety standard, but there was no legal requirement to recall and repair the product. To implement the notification requirement, this agency adopted a regulation, 49 CFR Part 577, *Defect Notification*. It also adopted 49 CFR Part 573, *Defect Reports*, which requires a manufacturer to report to us periodically on notification campaigns.; Effective December 27, 1974, the Act was amended (Section 151 an following sections) to require mandatory notification, and remedy. We have proposed a new Part 577 to implement the new requirements. The public comments on the proposal are still being evaluated and the final rule has not been issued. I enclose copies of the Act, Part 573, Part 577, and proposed Part 577 for your information, and will be happy to answer any questions you have concerning them.; To address your specific concerns: the fact that a product fails one o our tests does not *per se* establish a failure to comply with a Federal motor vehicle safety standard. In the usual case the manufacturer is afforded an informal opportunity to present its views regarding the test failure. Errors in testing or test machines may be brought to our attention which have the effect of negating the test results. Or the manufacturer may be convinced of its noncompliance and voluntarily announce a notification/recall campaign. Or the manufacturer may be directed by this agency to furnish notification after a public hearing on the matter. The agency in the latter circumstance will issue its own press release announcing the recall. Notification must be made 'within a reasonable time' after a determination of non-compliance or safety-related defect (Sec. 153(b)). If that determination is made by the government, it may prescribe a time period that it regards as reasonable.; There is no 'recent' Goodyear Tire recall of 12,500 tires as you state though the company did recall 12,602 tires in January 1973. Without knowing the size and type of the tires you are concerned about I cannot comment further.; I am returning your stamps. Yours truly, Richard B. Dyson, Assistant Chief Counsel |
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ID: aiam3330OpenMr. Kenneth W. Rix, Vice President, Great Plains Industries, Inc., 1711 Longfellow Lane, Wichita, KS 67207; Mr. Kenneth W. Rix Vice President Great Plains Industries Inc. 1711 Longfellow Lane Wichita KS 67207; Dear Mr. Rix: This responds to your letter of July 31, 1980, concerning a evaporative cooler you are considering manufacturing for use on motor vehicles. You explained that the unit would mount just outside the upper portion of the passenger window and would block approximately the upper 3 1/2 inches and protrude to the right of the drip rail approximately 10 inches. The following discussion answers your questions and outlines your responsibilities under the National Traffic and Motor Vehicle Safety Act (The Act, 15 U.S.C. 1381 *et seq*., a copy of which is enclosed).; You first asked whether your evaporative cooler would violate an Federal safety regulations. The agency has not issued and Federal motor vehicle safety standard directly establishing requirements for evaporative coolers. However, as explained below, installation of your cooler may be affected by the agency's proposed standard on direct fields of view. That proposal would prohibit certain obstructions in the driver's field of view. I have enclosed a copy of that notice of proposed rulemaking. (The agency does not plan to take final action on this proposal until early next year.); If the field of direct view standard is adopted, then installation o an evaporative cooler in a new vehicle prior to the vehicle's sale to the first purchaser could be affected by section 108(a)(1)(C) of the Act, and the agency's certification regulation (49 CFR 567, a copy of which is enclosed). If a cooler is installed as an add-on item of motor vehicle equipment by a vehicle dealer prior to the vehicle's delivery to the first purchaser, then section 567.7 of the certification regulation would apply. That section provides that a person who alters a previously certified vehicle prior to its first purchase must certify that the vehicle, as altered, still conforms to all applicable standards. Thus, a new vehicle would have to comply with the fields of view requirements with the cooler installed.; Whether or not your cooler is covered by a Federal safety standard, a a manufacturer of motor vehicle equipment you are required to comply with the provisions of the Act pertaining to safety-related defects (sections 151-159, 15 U.S.C. 1411-1419). Thus, if your company learns of a defect relating to motor vehicle safety in its evaporative coolers, you would be required to notify this agency, as well as owners, purchasers or dealers of the equipment, concerning the defect and to remedy the defect without charge. Parts 573, 576, 577 and 579 of the agency's regulations (49 CFR 573, 576, 577 and 579) define in detail a manufacturer's responsibilities with regard to safety-related defects. I have enclosed copies of those regulations.; You also asked whether you must check each state code prior to sale o your evaporative cooler in that state, since some states may have regulations that are more restrictive than the Federal regulations. In the absence of a Federal standard directly affecting evaporative coolers, state regulations would govern the sale of your cooler. If there was a Federal standard affecting the installation of your cooler, then the Federal regulation may preempt conflicting State regulations. Section 103(d) of the Act provides that no State may have a standard 'applicable to the same aspect of performance' of a motor vehicle or item of motor vehicle equipment, unless the state standard is 'identical to the Federal standard.' The Act does authorize State (sic) to establish higher standards of performance than the applicable Federal standard for vehicles or equipment procured for its own use. A determination of whether a Federal standard on direct fields of view would preempt a state standard on the same subject can only be made on a case-by-case basis after final action is taken on the field of view proposal and after reviewing the particular State standard.; You also asked whether you could use certain statements on your coole advising people to check state regulations before installing the cooler. The validity of such statements would be regulated by state law. Finally, you asked how you could obtain copies of state vehicle codes and information about obtaining a wavier (sic) or amendment of such codes. A law library may have copies of such codes. Otherwise, you will probably have to write to each State agency regulating motor vehicles to obtain a copy of their codes. I hope this information is of help to you. Please contact Steve Oesch of my office if you have any further questions about Federal regulations affecting your product at (202-426- 2992).; Sincerely, Frank Berndt, Chief Counsel |
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ID: aiam3760OpenMr. Steve Lampeas, 117 Aldershot Lane, Manhasset, NY 11030; Mr. Steve Lampeas 117 Aldershot Lane Manhasset NY 11030; Dear Mr. Lampeas: This is in reply to your letter of October 13, 1983, concerning th legality under Federal laws of your patented device, the 'Trunk Truck.' It appears from the material you enclosed that the device extends in twin booms from the rear of the car, and that a stop lamp or taillamp is mounted at the end of each boom (you refer to it as a 'natural extension' of these lamps).; Under the National Traffic and Motor Vehicle Safety Act, no perso (except the vehicle owner) may modify a vehicle so that equipment that is on the vehicle pursuant to a Federal motor vehicle safety standard is 'rendered inoperative in whole or in part.' Therefore, you must assure yourself that all requirements of Federal Motor Vehicle Safety Standard No. 108 continue to be met with respect to rear lighting. This would include not only the lamps at the end of the booms, but those remaining on the car. In addition to stop lamps and taillamps, rear lighting includes, (sic) turn signal lamps, back up lamps, and license plate lamps. As on other load-bearing vehicles, such as boat trailers, these lamps should continue to be visible even with a load installed.; You should also ask the States whether such a device is legal. State have jurisdiction over the use of motor vehicles within their borders.; Sincerely, Frank Berndt, Chief Counsel |
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ID: aiam2872OpenMr. Charles J. Kerr, Southwest Research Institute, 6220 Culebra Road, Post Office Drawer 28510, San Antonio, TX 78284; Mr. Charles J. Kerr Southwest Research Institute 6220 Culebra Road Post Office Drawer 28510 San Antonio TX 78284; Dear Mr. Kerr: This responds to your June 27, 1978, letter concerning the requirement of Safety Standard No. 207 as they would apply to pedestal seat assemblies for use in van vehicles. You ask whether your test methodology is consistent with the requirements of the standard and whether the pedestal base is considered part of the seat assembly.; As you know, the agency does not approve a manufacturer's test methods A manufacturer must exercise due care to ascertain that his product is in compliance with all applicable motor vehicle safety standards and regulations. While your test methods appear to be reasonable, the agency will test seats in the vehicle rather than on a surrogate test frame. You must exercise due care to assure that your simulated test is a true determination whether the seats would comply with the standard when tested as provided in that standard. (The vehicle manufacturer is, of course, responsible for compliance with Standard 207.); Regarding your second question, the pedestal base would be considere part of the seat assembly for purposes of Standard 207. This means that the agency would test the entire assembly by applying a force of 20 times the combined weight of the seat and the pedestal, contrary to your simulated test procedure of using only the weight of the seat frame and adjuster, without the pedestal base attached.; Finally, the force requirements of Safety Standard No. 210, *Seat Bel Assembly Anchorages*, (5,000 pounds) are applied simultaneously with the force requirements in Standard No. 207, if the anchorages are connected to the vehicle seat, to the pedestal, or to the pedestal base.; Please contact this office if you have any further questions, an please excuse the delay in this response.; Sincerely, Joseph J. Levin, Jr., Chief Counsel |
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ID: aiam1248OpenMr. Delbert A. Russell, Jr., Auto Safety Research Center, 613 Oak Street, Columbus, OH 43216; Mr. Delbert A. Russell Jr. Auto Safety Research Center 613 Oak Street Columbus OH 43216; Dear Mr. Russell: This is in response to your letter of June 27, 1973, which request information on the requirements of Standard 206, *Door Locks and Door Retention Components*, and suggests that door locking mechanisms should prevent operation of the inside and outside handles (latch release controls) of both front and rear doors.; The standard presently requires that engagement of the front-doo locking mechanism on passenger cars, multi-purpose passenger vehicles, and trucks render the outside door handle (latch release control) inoperative. On passenger cars and multipurpose passenger vehicles, engagement of the rear- door locking mechanism must render both inside and outside handles inoperative. Your suggestion that inside door handles also be rendered inoperative was proposed in 1967 as an initial standard, but it was determined at that time that ease of escape in the event of accident made one-step operation of the door more desirable. It was concluded that the vehicle operator would have sufficient control over children in the front seat to permit such override operation.; We are still interested in the best arrangement of locking mechanism and override at the various seating positions. At the moment, available accident data does not justify further rulemaking. Your comments will be fully considered in the event we decide to take further action.; Yours truly, Richard B. Dyson, Assistant Chief Counsel |
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ID: aiam3275OpenMr. Philip J. Carpenter, Administrative Engineer, Miller Tilt-Top Trailer, Inc., 450 S. 992 Street, P.O. Box 14247, Milwaukee, Wisconsin 53214; Mr. Philip J. Carpenter Administrative Engineer Miller Tilt-Top Trailer Inc. 450 S. 992 Street P.O. Box 14247 Milwaukee Wisconsin 53214; Dear Mr. Carpenter: This is in response to your letter of April 2, 1980, in which yo request approval for the vehicle identification numbering (VIN) system Miller Tilt-Top Trailer, Inc., proposes to use to satisfy the requirements of Federal Motor Vehicle Safety Standard 115 (49 CFR 571.115).; The National Highway Traffic Safety Administration does not approve manufacturer's compliance with the safety standard, as manufacturers serve as self-certifiers under the National Traffic and Motor Vehicle Safety Act. However, my office has reviewed your proposed system. Based on our understanding of the information that you have provided, your system apparently complies with Standard No. 115. We would also recommend that when you submit information to the agency pursuant to S6 of the standard, you follow each 'series' designation (4th and 5th characters of the VIN) with the phrase 'rectangular, flat platform trailer and body.'; Sincerely, Frank Berndt, Chief Counsel |
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ID: aiam1618OpenMr. K. Nakajima, Director/General Manager, Toyota Motors Sales, U.S.A., Inc., Lyndhurst Office Park, 1099 Wall Street, West, Lyndhurst, NJ 07071; Mr. K. Nakajima Director/General Manager Toyota Motors Sales U.S.A. Inc. Lyndhurst Office Park 1099 Wall Street West Lyndhurst NJ 07071; Dear Mr. Nakajima:#This is in response to your letter of September 9 1974, requesting an interpretation of Federal Motor Vehicle Safety Standard No. 101, specifically, whether Toyota should identify controls with words as well as symbols.#Your use of symbols alone, without the words specified in Column 2 of Table 1 to identify the headlamp, hazard warning, and washer/wiper controls on the 1974 Corona model, is not in compliance with the standard. Symbols are merely an option which may be used in addition to the mandatory word identification.#I have forwarded a copy of your letter to the NHTSA Office of Standard Enforcement, for such action as it deems necessary.#Your truly, Richard B. Dyson, Acting Chief Counsel; |
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ID: aiam3625OpenConfidential; Confidential; Dear Confidential: This is in reply to your letter of October 15, 1982, asking for a interpretation of Motor Vehicle Safety Standard No. 123, *Motorcycle Controls and Displays*. You have asked whether the standard permits three-wheeled motorcycles to be equipped with a reverse gear.; Standard No. 123 applies only to motorcycles with handlebars, which ar generally those machines with two wheels. As the standard is silent with respect to reverse gears, the agency considers that a manufacturer of a three-wheeled motorcycle with handlebars may provide and locate a reverse gear change mechanism wherever he deems appropriate.; This office can offer no comments on three-wheeled motorcycle safety i general. However, I suggest that you contact NHTSA's Office of Research and Development. Several years ago it conducted a study of three-wheeled vehicles, and as I recall, a configuration with two wheels in front and one behind was found to offer greater stability than the converse.; We shall delete your name and that of your company from the publicl available copies of this letter, in accordance with your wish for confidentiality.; 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.