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: aiam3781OpenMr. Jeff S. Brantner, 316 Whitebirch, Wenatches, WA 98801; Mr. Jeff S. Brantner 316 Whitebirch Wenatches WA 98801; Dear Mr. Brantner: This responds to your letter of November 9, 1983, to the Urban Mas Transit Administration, which was forwarded to this agency for reply, concerning legal requirements regulating window stickers. The following discussion addresses the Federal requirements applicable to sticker or other films applied to glazing materials in motor vehicles.; The National Highway Traffic Safety Administration has the authority t govern the manufacture of new motor vehicles and motor vehicle equipment. Pursuant to the National Traffic and Motor Vehicle Safety Act, we have promulgated Federal Motor Vehicle Safety Standard No. 205, *Glazing Materials*, which specifies performance and location requirements for glazing used in vehicles. These requirements include specifications for minimum levels of light transmittance (70 percent in areas requisite for driving visibility, which includes all windows in passenger cars) and abrasion resistance.; The agency has stated in past interpretations that films such as th type referred to in your letter are not glazing materials themselves, and would not have to comply with Standard No. 205. However, installation of such films on new motor vehicles would be prohibited if the vehicle glazing no longer complied with the light transmittance or abrasion requirements of the standard. If a vehicle manufacturer or a dealer places the film on glazing in a vehicle prior to sale of the vehicle, that manufacturer or dealer has to certify that the glazing continues to be in compliance with the requirements of Standard No. 205. Section 108(a)(1) prohibits any person from offering for sale or selling any motor vehicle or equipment that fails to comply with applicable safety standards.; After a new vehicle has been sold to the consumer, he may alter hi vehicle as he pleases, so long as he adheres to all State requirements. Under Federal law, the owner could install the film on glazing in his vehicle whether or not such installation adversely affected the light transmittance and abrasion resistance of his vehicle's glazing. It should be noted, however, that section 108(a)(2)(A) of the National Traffic and Motor Vehicle Safety Act provides that no manufacturer, distributor, dealer or motor vehicle repair business shall knowingly render inoperative any device or element of design installed on or in a motor vehicle in compliance with an applicable motor vehicle safety standard. 'Render inoperative' means to remove, disconnect or degrade the performance of a system or element of design installed pursuant to the Federal safety standards. Thus, none of those persons may knowingly install a film on a vehicle for its owner if that act would render inoperative the light transmittance or abrasion resistance of the vehicle glazing. Whether this would be the case would have to be determined by the person making the installation. Violation of this section can result in Federal civil penalties up to $1,000 for each violation.; Please contact Stephen Oesch of my staff if you have any furthe questions (202- 426-1834).; Sincerely, Frank Berndt, Chief Counsel |
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ID: aiam0007OpenMr. Louis F. Wilson Instant Traffic Lights 2580 W. Venice Boulevard Los Angeles, CA 90019; Mr. Louis F. Wilson Instant Traffic Lights 2580 W. Venice Boulevard Los Angeles CA 90019; Dear Mr. Wilson: This is in reply to your letter of February 20, 1991 with respect to the acceptability under Federal law of your product, the 'Instant Traffic Light. I regret that we do not appear to have a record of your earlier letters to the agency on this subject. The 'Instant Traffic Light' is a four-section unit intended to perform three functions, each indicated by a different color. A green light appears when the accelerator is applied, an amber light when the accelerator is released, and a red light when the brakes are applied. The lamp's shipping carton shows the unit mounted on the rear parcel shelf behind the rear window. The text on the carton says that the lamp is easy to assemble. You have asked whether the product meets Standard No. 108, whether it would be 'legal' in the U.S. 'and her territories', and whether the product could replace, or be an option to, the requirements of Standard No. 108 for the center high-mounted stop lamp. Finally, of the l6 States that have responded to your inquiry, an equal number (six) have indicated that the lamp is and is not acceptable to them, while the remaining four 'said they will follow the Federal requirement.' Standard No. 108 does not permit the center high-mounted stop lamp to be combined with any other lamp. This means that your product could not be used as original equipment on a passenger car, whether as standard equipment or as an option, or marketed and sold as replacement equipment for a center lamp on a passenger car that was originally equipped with it. However, Standard No. 108 does not apply to the 'Instant Traffic Light' if it is marketed or sold exclusively for use on passenger cars that were not originally required to be manufactured with the center stop lamp, i.e., those cars that were manufactured before September 1, l985. Under this circumstance, the question of the legality of use of the device is to be determined by the laws of the individual States. The 'territories' are 'States' for purposes of this discussion. Since there is no legal prohibition under Federal law for installation of your lamp only on older passenger cars, we presume that the four States that reserved their decision would permit it on pre - l985 vehicles registered and/or operating within their borders. We are aware that, nevertheless, there may be some owner interest in replacing original equipment center stop lamps with your product. We would like to advise that such replacement would be a violation of the National Traffic and Motor Vehicle Safety Act, if performed by a manufacturer, distributor, dealer, or motor vehicle repair business. There is no such restriction upon a vehicle owner who performs the replacement of the lamp himself. I hope that this responds to your questions. Sincerely, Paul Jackson Rice Chief Counsel; |
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ID: aiam5205OpenMr. Dave Beidleman Arizona Department of Transportation Equipment Services; Mr. Dave Beidleman Arizona Department of Transportation Equipment Services; FAX 602-258-5193 Dear Mr. Beidleman: We have received your FAX of Jul 2, 1993, to the attention of Taylor Vinson of this Office, asking for an interpretation of Motor Vehicle Safety Standard No. 108 as it pertains to the location of rear identification lamps. The rear configuration of l0 dump trucks that are being constructed for the Arizona DOT is such that you would like to raise the center lamp of the three- lamp identification lamp cluster approximately 1 1/2 inches, the two outer lamps of the array cannot be raised due to the positioning of the underbody tailgate release mechanism. Table II of Standard No. 108 requires that the identification lamps be mounted 'as close as practicable to the top of the vehicle, at the same height, and as close as practicable to the vertical centerline.' In our opinion, the lamps in an identification lamp cluster must be equally spaced laterally and mounted at the same height in order for the identification lamp system to perform its intended purpose. Therefore, I am afraid the agency cannot accept a lamp display that differs. Although the lamps could be mounted on the rear of the cab, we understand that in that position they could be obscured by the top lip of the dump body. We realize that the contractor has pre-punched holes for the lamps, which would be flush-mounted in the rear cross sill of the truck body. If a way were found to cover the holes, there are surface-mounted lamps available which could be mounted at the same height (your desired height for the center lamp) in a manner than should not affect the positioning of the underbody tailgate release mechanism. Sincerely, John Womack Acting Chief Counsel; |
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ID: aiam0457OpenMr. J. G. Abbott, Transportation Chemicals, Development & Service, Dow Chemical Europe, S.A., Todi-Strasse 68, 8810 Horgen 2, Switzerland; Mr. J. G. Abbott Transportation Chemicals Development & Service Dow Chemical Europe S.A. Todi-Strasse 68 8810 Horgen 2 Switzerland; Dear Mr. Abbott: This is in reply to your letter of September 24 to Francis Armstron regarding the effective date of the new Federal motor vehicle brake fluid standard, No. 116.; The effective date of March 1, 1972, means that any vehicl *manufactured* on or after that date for sale in the United States must be equipped with brake fluid meeting Motor Vehicle Safety Standard No. 116.; Sincerely, Lawrence R. Schneider, Chief Counsel |
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ID: aiam4947OpenGordon W. Didier, Esquire Butzel Long Suite 200 32270 Telegraph Birmingham, Michigan 48010-4996; Gordon W. Didier Esquire Butzel Long Suite 200 32270 Telegraph Birmingham Michigan 48010-4996; "Dear Mr. Didier: This responds to your request for an interpretatio of Federal Motor Vehicle Safety Standard No. 118 Power Windows (49 CFR 571.118), on behalf of your client, a manufacturer of automobile sunroofs. As you noted in your letter, the agency has published a final rule amending Standard No. 118 in the April 16, 1991 edition of the Federal Register (56 FR 15290). You requested clarification of certain requirements in that final rule. The agency has received several petitions for reconsideration of the final rule amending Standard No. 118. The agency is currently reviewing the merits of each petition. The agency will issue a notice in the Federal Register granting and/or denying the petitions. In that notice, the agency will also address the concerns raised in your request for an interpretation on Standard No. 118. Please let us know if you have any questions about the issues raised in your letter after our response to the petitions for reconsideration has been published and you have had the opportunity to review it. If you need more information on this subject, please feel free to contact Dorothy Nakama of my staff at this address, or by telephone at (202) 366-2992. Sincerely, Paul Jackson Rice Chief Counsel"; |
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ID: aiam2190OpenMr. F. A. McNiel, 611 Bouldin Avenue, Austin, TX, 78704; Mr. F. A. McNiel 611 Bouldin Avenue Austin TX 78704; Dear Mr. McNiel: This is in reply to your petition of November 7, 1975, 'for th correction of subsection S4.5.4 and S4.6(b) as set forth by existing Federal Motor Vehicle Safety Standard No. 108.'; It is your opinion that S4.5.4, which requires activation of stop lamp upon application of the service brakes, is design restrictive, and 'leaves no opportunity for innovation by the private sector for other solutions for the activation of a motor vehicle's stoplamps' (sic). You have suggested that S4.5.4 be amended to include at its end 'or by other beneficial means which will not impair the lighting system or the mechanical functioning of the vehicle'.; Any performance standard is design restrictive to some extent, it mus restrict manufacturers to designs that meet the desired performance requirements. Its validity as a performance standard depends on whether the restrictions of the standard are only as narrow as reasonably necessary to achieve the desired safety performance. In this case we have found that the requirement meets this test. A signal to other drivers that the service brakes are being applied is precisely the performance being sought in S4.5.4. A signal based on some other condition (e.g., vehicle deceleration) might not be as timely, or might fail altogether to operate at the critical moment (as where it is based on lifting the accelerator pedal). Since the requirement is limited to the desired safety performance, we find it valid, and your petition in this area is denied.; You also ask for an amendment of S4.6(b) to include 'rear lamps' amon those that may be flashed for signalling purposes, since you believe that conventional wiring circuits presently allow these lamps to be flashed when headlamps are flashed. When the headlamps are flashed by means of the on-off switch, it is true that rear lamps will flash. But that type of flashing is in no way restricted by the standard. The flashing intended to be regulated by S4.6(b) is by automatic means (see S3 definitions) and, except for rear turn signal lamps, these automatic devices would not be connected to rear lamp circuits. Thus, there appears to be no need for the amendment you suggest and your petition is accordingly denied.; We appreciate your continuing efforts on behalf of traffic safety. Sincerely, Robert L. Carter, Associate Administrator, Motor Vehicl Programs; |
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ID: aiam5655OpenMr. Kenneth W. Easterling Plan B Engineering, Inc. 26399 The Old Road 14-106 Stevenson Ranch, CA 91381; Mr. Kenneth W. Easterling Plan B Engineering Inc. 26399 The Old Road 14-106 Stevenson Ranch CA 91381; Dear Mr. Easterling: This responds to your letter of November 16, 1995 asking for our opinion of 'G-Lamps', ('proportional deceleration indicator lamps) intended as a rear end collision avoidance device. Your system would flash the stop lamps proportionally to the rate of deceleration. Over the years, the agency has received many requests for interpretations of the laws which it administers as they relate to deceleration warning systems. Our reply has been that it is impermissible to wire the stop lamp system so that it flashes, no matter what the purpose of the flashing. I enclose for your information, as a representative reply, a copy of our letter of July 30, 1993, to Wayne Ferguson of the Virginia Department of Transportation, which fully sets forth our views and interpretations. If you have questions about these matters, you may telephone Taylor Vinson of this office at 202-366-5263. Sincerely, Samuel J. Dubbin Chief Counsel Enclosure; |
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ID: aiam5340OpenMr. John Moore Ferrucci Nurseries Rd 1, Box 299 Piney Hollow Rd. Newfield, NJ 08344; Mr. John Moore Ferrucci Nurseries Rd 1 Box 299 Piney Hollow Rd. Newfield NJ 08344; "Dear Mr. Moore: This responds to your letter of February 4, 1994 requesting verification of a statement made by a National Highway Traffic Safety Administration (NHTSA) employee that you are allowed to install passenger seats in a van used for farm transportation if you comply with the safety regulations. In a phone conversation with Mary Versailles of my staff, you explained that you would like to add seats to the rear of a 14 foot cargo van which the nursery owns. You would be performing this work yourself. As explained below, Federal law does not apply to situations where vehicle owners alter their own vehicles. I am pleased to have this opportunity to explain our laws and regulations to you. NHTSA is authorized under the National Traffic and Motor Vehicle Safety Act (15 U.S.C. 1381 et seq., Safety Act) to issue motor vehicle safety standards that apply to the manufacture and sale of new motor vehicles and new items of motor vehicle equipment. Section 108(a)(1)(A) of the Safety Act (15 U.S.C. 1397(a)(1)(A)) prohibits any person from manufacturing, introducing into commerce, selling, or importing any new motor vehicle or item of motor vehicle equipment unless the vehicle or equipment item is in conformity with all applicable safety standards. NHTSA has exercised its authority to establish five safety standards which could be relevant to installation of a seat in a used vehicle: Standard No. 207, Seating Systems, Standard No. 208, Occupant Crash Protection, Standard No. 209, Seat Belt Assemblies, Standard No. 210, Seat Belt Assembly Anchorages, and Standard No. 302, Flammability of Interior Materials. Standards Nos. 207, 208, 210, and 302 apply, with certain exceptions that are not relevant to your situation, to vehicles and not directly to items of equipment. Standard No. 209, however, applies to seat belt assemblies as separate items of motor vehicle equipment, regardless of whether the belts are installed as original equipment in a motor vehicle or sold as replacements. Thus, if you install new seat belts on the seats, the manufacturer is required to certify that the seat belts comply with Standard No. 209. If a seat is installed in a used motor vehicle, the seat, as an item of equipment, does not have to comply with any Federal standards. However, 108(a)(2)(A) of the Safety Act provides, in pertinent part: No manufacturer, distributor, dealer, or motor vehicle repair business shall knowingly render inoperative, in whole or part, any device or element of design installed on or in a motor vehicle or item of motor vehicle equipment in compliance with an applicable Federal motor vehicle safety standard. . . . None of these entities could install seats in your van if it caused the vehicle to no longer comply with any of the safety standards. Please note, however, that the 'render inoperative' prohibition does not apply to modifications vehicle owners make to their own vehicles. Thus, Federal law would not apply in a situation where you, as an individual vehicle owner, installed seats in your own vehicles, even if the installation were to result in the vehicle no longer complying with the safety standards. However, you should be aware that individual States have the authority to regulate modifications that individual vehicle owners may make to their own vehicles. While Federal law would not apply to a modification you make to your own vehicle, I nonetheless urge you to exercise care in installing the seats and to install seat belts on the seats. The seats and seat belts will not provide any protection to occupants if they separate from the vehicle frame in a crash. Also, you may wish to consult a private attorney familiar with the law in the State of New Jersey regarding potential liability in tort for your business in these circumstances. I hope you find this information helpful. If you have any other questions, please contact Mary Versailles of my staff at this address or by phone at (202) 366-2992. Sincerely, John Womack Acting Chief Counsel"; |
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ID: aiam2485OpenMr. William Shapiro, Regulatory Analysis Engineer, Volvo of America Corporation, Rockleigh, NJ 07647; Mr. William Shapiro Regulatory Analysis Engineer Volvo of America Corporation Rockleigh NJ 07647; Dear Mr. Shapiro: This is in reply to your letter of January 4, 1977, asking fo confirmation of your interpretation that Motor Vehicle Safety Standard No. 108 permits the installation of white reflex reflectors on the front of a passenger car.; You are correct in your interpretation. While Standard No. 108 does no require any reflex reflector on the front of a passenger car, pursuant to S4.1.3 they may be added provided that they do not impair the effectiveness of the required lighting equipment.; Sincerely,Frank A. Berndt, Acting Chief Counsel |
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ID: aiam0142OpenMr. Jack Flynn, P.O.B. Manufacturing Company, 11100 Kenwood Road, Cincinnati, OH 45242; Mr. Jack Flynn P.O.B. Manufacturing Company 11100 Kenwood Road Cincinnati OH 45242; >>>Attention: Standards Department<<< Dear Mr. Flynn: Thank you for your letter of February 21, 1969, concerning glazin materials.; I am enclosing a copy of Federal Motor Vehicle Safety Standard No. 20 and, since you manufacture and distribute sealing compounds, a copy of Federal Motor Vehicle Safety Standard No. 212.; ASA Standard Z26.1-1966, incorporated by reference in Standard No. 205 can be obtained at a cost of $3.50 from the United States of America Standards Institute, 10 East 40th Street, New York 10016.; SAE Recommended Practice J673a, August 1967, incorporated by referenc in Standard No. 205, can be obtained from the Society of Automotive Engineers, Inc., Two Pennsylvania Plaza, New York, New York, 10001.; We are in the process of changing paragraph S.3.2 of Standard No. 205 You may want to keep up with future amendments to these and other standards, therefore, I am enclosing a copy of form HS-13, Mailing List Questionnaire and subscription information for the *Federal Register*. Either or both of these will enable you to receive information in your areas of interest in all future motor vehicle safety rulemaking actions.; Sincerely, Clue D. Ferguson, Director, Office of Standards o Crash-Injury Reduction, Motor Vehicle Safety Performance Service; |
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.