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: aiam0012OpenMr. Stanley L. Dembecki 2303 N. 44th Street, #14-237 Phoenix, AZ 80058; Mr. Stanley L. Dembecki 2303 N. 44th Street #14-237 Phoenix AZ 80058; Dear Mr. Dembecki: This responds to your letter of April 24, 1991 commenting on my letter to you of April 8. In response to your request to review and comment on your video tape of your device, I asked our research and development office to review it. They indicated that although the device has some intuitive appeal, there is no technical basis to show that it would reduce accidents. In fact, our agency sponsored a field test of a similar system that flashed the center highmounted stop lamp. We found no significant difference in accident rates compared to a steady-burning signal. Attached is the abstract page of this study for your information. In closing, I note your comment that 'My l99l Oldsmobile was retrofitted within l5 minutes' with the module causing the center high mounted stop lamp to flash. Since you did not say that you had performed the retrofit, we assume that it 'was retrofitted' by another person. As I advised you on April 8, the center lamp must be steady-burning. Further, the National Traffic and Motor Vehicle Safety Act (specifically Title l5, United States Code, Section 1397(a)(2)(A)) forbids a 'manufacturer, distributor, dealer, or motor vehicle repair business' from rendering inoperative in whole or in part any equipment on a vehicle which has been installed pursuant to a Federal motor vehicle safety standard. We interpret this as forbidding the installation of equipment that would take a vehicle out of compliance with a Federal safety standard, i.e., that converts the steady-burning center lamp into a flashing one. However, the prohibition does not apply to individual owners of vehicles if they are not 'manufacturers, distributors, dealers, and motor vehicle repair businesses' capable of performing the modification themselves. Sincerely Paul Jackson Rice Chief Counsel Enclosure; |
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ID: aiam4728OpenMs Joan E. Fogelman Lund & Pullara, Inc. P.O. Box 10148 Riviera Beach, FL 33404; Ms Joan E. Fogelman Lund & Pullara Inc. P.O. Box 10148 Riviera Beach FL 33404; FAX 305-842-9836 Dear Ms. Fogelman: This is in reply to your FAX o April 2, l990, to Taylor Vinson of this Office, with reference to a l985 Mercedes-Benz 280SE sedan being imported from the Bahamas temporarily, for the purpose of repair. You have stated that 'U.S. Customs wants a reassurance that they will not be held accountable if for some unforseen happening, this vehicle is not properly exported.' Although the new DOT vehicle importation regulations effective January 31, l990, make no specific provision for temporary importation of a nonconforming motor vehicle for repairs, when such a vehicle is owned by a nonresident of the United States and registered in a country other than the U.S., it is acceptable to this agency for the nonresident owner to enter it under the provisions of 49 CFR 591.5(d), the declaration by an importer who provides his passport number and country of issue that he is a nonresident importing the vehicle for personal use for a period not to exceed one year and will not sell the vehicle during that time. Such an entry is not accompanied by the new DOT conformance bond, which is required only for entries pursuant to 591.5(f) and (g). I do not know what Customs means by being held 'accountable' if the vehicle is not properly exported. You have stated that it will be accompanied by a Customs bond, and I assume that if the terms of that bond are violated Customs will take whatever enforcement action against the vehicle and its owner is deemed appropriate under the bond. Sincerely, Stephen P. Wood Acting Chief Counsel; |
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ID: aiam3517OpenThe Honorable Phil Sharp, House of Representatives, Washington, DC 20515; The Honorable Phil Sharp House of Representatives Washington DC 20515; Dear Mr. Sharp: This responds to your recent letter requesting information on behalf o your constituent, Mr. Mark Lecher. Mr. Lecher is under the impression that there is some new law 'banning cars with dark-tinted windows.' He is particularly concerned that he will have to replace the windows on his Datson (sic) pickup.; The National Highway Traffic Safety Administration issues safet standards and regulations governing the manufacture of new motor vehicles and motor vehicle equipment. There is a safety standard which specifies performance and location requirements for glazing materials used on motor vehicles (Standard No. 205). However, the requirements of this standard as they relate to tinting have not changed in years. The standard currently requires the windshield and front side windows in cars and trucks (i.e., windows necessary for driving visibility) to have a luminous transmittance of at least 70 percent. Other windows may be tinted as darkly as the manufacturer wishes. If the windows in Mr. Lecher's pickup were factory-installed, they are presumably in compliance with Standard No. 205. Therefore, Mr. Lecher should not worry about having to alter his windows. There is no new Federal law or regulation, nor any proposed rule, to change the requirements of Standard No. 205 in this regard.; Mr. Lecher might be referring to a State law or regulation. W understand that some states are considering prohibitions against the use of dark tinting films which can be applied to existing vehicle windows. Such State laws would not require Mr. Lecher to alter the windows on his pickup, however, if the windows are the original glazing installed by the manufacturer in compliance with the Federal standard. This is because Section 103(d) of the National Traffic and Motor Vehicle Safety Act, as amended 1974 (15 U.S.C. 1392, *et seq*.) pre-empts any state law which is applicable to the same aspect of performance as a Federal safety standard.; Standard No. 205 would pre-empt any State law which attempted t specify the amount of tinting that a piece of new motor vehicle glazing could have. Standard No. 205 would not pre-empt a State law which prohibits the applications of films or decals on existing glazing, however, since Standard 205 does not apply to the use of glazing after it has been purchased by a consumer. I suggest that Mr. Lecher contact his State Department of Motor Vehicles to find out about any activity in this area.; I am enclosing a copy of the Vehicle Safety Act for Mr. Lecher' information.; Sincerely, Frank Berndt, Chief Counsel |
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ID: aiam4378OpenMr. David M. Romansky, President, Atract Ad, 3400 Hwy 427, Sanford, FL 32771; Mr. David M. Romansky President Atract Ad 3400 Hwy 427 Sanford FL 32771; Dear Mr. Romansky: This is in reply to your letter of August 11, 1987 asking for ou 'evaluation and comments' on your proposed product. This product is an adhesive label that is applied to the center highmounted stop lamp. When the brakes are applied the words 'buckle-up' become visible to the driver of the car behind.; Our comments relate to the acceptability of your product under th National Traffic and Motor Vehicle Safety Act and Federal Motor Vehicle Safety Standard No. 108, *Lamps, Reflective Devices, and Associated Equipment*, and its relationship to State laws. The simplicity of the decal is such that it may be readily applied by anyone with no special expertise or tools. There will be no violation of the Act if the decal is applied by the vehicle owner. However, a vehicle in use is subject to the laws of each State in which it is registered or operated. We are not familiar with State laws governing partial obscuration of the center lamp. We suggest you write the American Association of Motor Vehicle Administrators, 1201 Connecticut Ave. N.W., Washington, D.C. 20036 for further information. There is at least the theoretical possibility that it may raise a question of liability, or provide a defense, in accident suits involving rear end collisions.; Questions of compliance would be raised were the decal applied by moto vehicle manufacturers, dealers, distributors, or repair businesses, either before or after sale of the vehicle. In essence, a new vehicle must comply with all applicable Federal motor vehicle safety standards at the time of its first sale, and the persons listed above must do nothing during the life of the car to affect the compliance of a device installed in accordance with a safety standard. If the decal reduces the effective projected luminous area of a lamp to less than 4 1/2 square inches, interferes with light output at any of 13 specified photometric test points, or renders the signal not visible to the rear through a horizontal angle from 45 degrees to the left to 45 degrees to the right of the longitudinal axis of the vehicle, the lamp will not conform. A person creating a noncompliance may be subject to a civil penalty of up to $1000 for each violation.; If you have any further questions we will be pleased to answer them. Sincerely, Erika Z. Jones, Chief Counsel |
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ID: aiam1480OpenMr. Charles W. Murphy, Safety Director, City of Philadelphia, 1600 Municipal Services Bldg., Philadelphia, PA 19107; Mr. Charles W. Murphy Safety Director City of Philadelphia 1600 Municipal Services Bldg. Philadelphia PA 19107; Dear Mr. Murphy: This is in reply to your letter of March 5, 1974, inquiring whethe manufacturers of 4-door sedans to be sold to the City of Philadelphia as police vehicles may, consistently with Federal requirements, remove the window and door handles from the rear doors. You state that the vehicle manufacturers claim that Federal requirements prohibit them from modifying the vehicle in this fashion.; Federal Motor Vehicle Safety Standard No. 206 (49 CFR 571.206) require each passenger car rear door to have a locking mechanism that is operable from within the vehicle and that, when engaged, renders the outside and inside door handles inoperative. This requirement applies to the locking mechanism. We do not interpret it to require an inside door handle. There are no Federal standards which require the installation of passenger car window handles.; The fact that in this case the vehicles are intended for government us is immaterial. To clarify the phone conversation which preceded your letter, Section 103(d) of the National Traffic and Motor Vehicle Safety Act (15 U.S.C. 1392(d)) allows a State or its political Subdivision to require that motor vehicles and motor vehicle equipment procured for its own use meet a higher standard of performance than the Federal safety standard, but all vehicles must meet the Federal safety standards.; We are pleased to be of assistance. Sincerely, Lawrence R. Schneider, Chief Counsel |
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ID: aiam4682OpenLarry S. Snowhite, Esq. Mintz, Levin, Cohn, Ferris, Glovsky and Popeo, P.C. 1825 Eye Street, NW Washington, D.C. 20006; Larry S. Snowhite Esq. Mintz Levin Cohn Ferris Glovsky and Popeo P.C. 1825 Eye Street NW Washington D.C. 20006; Dear Mr. Snowhite: This replies to your letters asking for determination 'that the sale into the aftermarket as well as aftermarket installation of the Advanced Brake Light Device ('ABLD')...would not violate' any of this agency's statutes or regulations. As you have described it, the ABLD 'consists of a sensor attached to the accelerator pedal that senses the rate at which the foot releases the accelerator pedal. This signal is sent to a processor unit, which determines whether the brake lights should be turned on, and the duration of the illumination until the brake is applied. The ABLD is set so that the brake light will go off unless the brake is applied within one second of the ABLD's activation...' You believe that this avoids providing a misleading signal. You further indicate the manufacturer's willingness to alter the time interval if NHTSA's favorable opinion is required for it. You have not defined the term 'aftermarket', but we shall assume that you mean sales to vehicle owners of equipment for installation on their vehicles (as contrasted with sales to dealers for installation on new vehicles before their delivery). There is no Federal motor vehicle safety standard that applies to the system described in your letter. This means that there are no Federal restrictions upon the importation, manufacture, or sale of the ABLD. Under the National Traffic and Motor Vehicle Safety Act (specifically, 15 U.S.C. 1397(a)(2)(A)), as you surmise, modifications to vehicles by a person other than the vehicle owner are permissible as long as they do not 'render inoperative, in whole or in part, any device...installed on...a motor vehicle...in compliance with an applicable Federal motor vehicle safety standard....' The essential question then is whether the installation of the ABLD renders partially or wholly inoperative the vehicle's stop lamps. As you know, in our interpretations on lighting equipment, we have noted a close relationship between the statute's rendering inoperative prohibition for the aftermarket with the standard's impaired effectiveness prohibition for supplementary original equipment. Primarily, maintaining that relationship is done in order to avoid regulatory inconsistency with interpretations under which installation of an item of aftermarket equipment might be deemed acceptable under the National Traffic and Motor Vehicle Safety Act, while its installation as original equipment would violate Standard No. 108. There are two types of supplementary original, or aftermarket, lighting equipment, those that operate independently of the lighting equipment that Standard No. 108 requires, and those that operate in connection with that equipment. A separate red rear fog lamp would be an example of the former. The ABLD is an example of the latter, because it has a direct effect upon the operation of the stop lamp. An aftermarket device that has an effect upon the operation of required lighting equipment cannot be deemed permissible unless that effect is consistent with the operation and purpose of the required equipment. As you stated, the SAE defines a stop lamp as one whose function indicates 'the intention of the operator of a vehicle to stop or diminish speed by braking'. You have argued that 'the ABLD is consistent because it 'clearly and unambiguously indicates' an operator's intent to apply the brake. Your client, however, does not make that claim for the ABLD, it concedes that 'there will be circumstances in which the brake will not be engaged after the ABLD is activated.' The heart of our concern is that while the standard requires the stop lamp to operate in only one particular circumstance, the ABLD causes the stop lamp to operate at an earlier time when the lamp is supposed to be unlighted. Further, the ABLD's activation of the stop lamp indicates only that the operator has released the accelerator. It does not necessarily follow that the brake pedal will later be applied. Under this fact situation, the stop lamps fulfill a purpose other than for which they are installed. This can only create the potential for confusion and dilution of the effectiveness of the stop signal. For the reasons stated above, we have concluded that installation of the ABLD i the aftermarket would render the stop lamps partially inoperative. Because this conclusion does not depend upon whether the ABLD would be acceptable using the different parameters of performance to which it is apparently capable of being adjusted, there appears to be no reason to discuss this matter with you before completion of this interpretation, which would further delay our response. We would like to discuss several other points. You have stated that 'illuminations of the brake lights for one second or less occur frequently during normal driving without the ABLD', and have sought to allay our concerns with the manufacturer's willingness to reduce the stop lamp activation time from one second to something less if that is required for a favorable interpretation. You have also provided information that the ABLD comes into operation only when the foot is released from the pedal at a rate consistent with an intent to apply the brake, as in an emergency situation. While we appreciate these arguments, we do not find them persuasive. The short periods of illumination to which you refer are occasioned by application of the brake pedal, no matter how brief that application is. The offer to reduce the activation time of the ABLD if it is not followed by a brake application would reduce but not eliminate stop lamp activation for purposes other than to indicate a stop or diminished speed. As for foot-movement time, there appears to be no indication in the University of Michigan study that you submitted that the ABLD was activated in traffic emergencies. The foot-movement time measurements seem consistent with removal of the foot from the accelerator under ordinary traffic situations, and thus there should have been no instances of ABLD activation. Your most recent letter contained a copy of a report of an independent field study of the ABLD in Israel, which 'found that rear-end accidents were reduced by 75 percent.' However, the report states that the ABLD-equipped vehicles ('except a few') were also equipped with center high-mounted stop lamps. Since any reductions in rear-end accidents that were experienced by the test fleets cannot be attributed solely to the ABLD, the data must be viewed as inconclusive. The acceptability for use of the ABLD must also be determined under the laws of the individual states. We are unable to advise you on these laws, and suggest that you get in touch with the American Association of Motor Vehicle Administrators (AAMVA) for further advice. Its address is 4600 Wilson Boulevard, Arlington, VA 22203. Sincerely, Stephen P. Wood Acting Chief Counsel; |
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ID: aiam3147OpenMr. Sonny Raidt, Performance Plus Products, Ltd., P.O. Box 5636, Greenville, MS 38701; Mr. Sonny Raidt Performance Plus Products Ltd. P.O. Box 5636 Greenville MS 38701; Dear Mr. Raidt: This is in response to the questions that you raised on October 23 1979, with Ms. Debra Weiner of my office concerning the legal and technical issues arising from the manufacture of auxiliary fuel tanks for use in pickup trucks. You noted that you are going into the business of manufacturing auxiliary fuel tanks, that you will not be involved in the installation of such tanks, and that you would like any advice that we might be able to provide as to the construction standards that should be followed in manufacturing such tanks.; I have enclosed a copy of a letter which was sent to a company tha planned to manufacture auxiliary fuel tanks for passenger cars and to do some installation. The legal principles enunciated in that letter are applicable to auxiliary fuel tanks intended for use in all types of motor vehicles except motor carriers in interstate commerce. Although your company is not planning to install auxiliary tanks, I think that you might find that the discussion of the legal issues that arise with respect to installation may be helpful in determining what safety margins should be built into these types of tanks.; As Ms. Weiner noted on the phone, this agency has not issued an standards applicable to the construction of auxiliary fuel tanks. However, the Federal Highway Administration, Bureau of Motor Carrier Safety has issued standards relevant to the construction of auxiliary fuel tanks for use in motor vehicles which are engaged in interstate commerce. I have enclosed a copy of these standards in hope that they will provide you with some suggestions as to what would constitute safe construction of an auxiliary fuel tank. In addition, the Society of Automotive Engineers has published standards pertinent to some aspects of the construction of fuel tanks. I have also enclosed copies of these.; I hope that you will find the enclosed material helpful. If you hav any further questions, please feel free to contact Ms. Weiner for further information.; Sincerely, Frank Berndt, Chief Counsel |
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ID: aiam5139OpenMr. Guy Dorleans International and Regulatory Affairs Manager Valeo 34, rue Saint-Andre 93012 Bobigny Cedex France; Mr. Guy Dorleans International and Regulatory Affairs Manager Valeo 34 rue Saint-Andre 93012 Bobigny Cedex France; "Dear Mr. Dorleans: We have received your letter of January 22, 1993 asking for an interpretation of Motor Vehicle Safety Standard No. 108 as it relates to aimability of headlamps. Valeo is currently studying new principles for aiming small circular headlamps. It appears that these headlamps will require unique aiming adaptors (meaning that the Hopkins universal adaptor cannot be used with them). These adaptors will be placed in the trunk of any vehicle with which they are supplied, and relevant instructions for use will be included in the vehicle operator's manual. Valeo has asked for confirmation that each version complies with Standard No. 108. Standard No. 108 does not require that an aiming adaptor be provided with a motor vehicle, only that the vehicle's headlamps be capable of mechanical aim. Therefore there is no legal requirement that an adaptor be provided. However, without such an adaptor, an owner of a vehicle with the new headlamps may encounter difficulties at State inspection stations where the Hopkins adaptor is in use, and at repair facilities when headlamps are replaced or after body work has been performed that necessitates reaim of headlamps. Therefore we believe that provision of the adaptor and aiming information would enhance consumer acceptance of the new headlamps. Sincerely, John Womack Acting Chief Counsel "; |
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ID: aiam2306OpenHonorable Robert P. Griffin, United States Senate, Washington, DC 20510; Honorable Robert P. Griffin United States Senate Washington DC 20510; Dear Senator Griffin: This is in response to your letter of May 6, 1976, forwarding petition from Gulf + Western Manufacturing Company for reconsideration of the bumper standard recently issued as Part 581 of Title 49 Code of Federal Regulations.; A number of requests for our view on the Gulf + Western petition hav been forwarded by members of Congress who have received copies of the Gulf + Western petition accompanied by a letter from Mr. James A. Graham.; It is the National Highway Traffic Safety Administration's policy t issue a notice of action taken on petitions for reconsideration within 120 days after publication of the final rule, unless action within that time is impracticable. Since the agency is currently in the process of considering the petitions received, it would not be appropriate for us to comment at this time on the remarks made by Gulf + Western.; I assure you that Gulf + Western's comments and the informatio contained in all of the petitions for reconsideration will receive thorough consideration. The agency's response to the petitions will be published in the *Federal Register*.; Sincerely, Frank Berndt, Acting Chief Counsel |
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ID: aiam5569OpenThomas L. Wright, Acting Manager MVS Customer Services State of New Jersey Department of Law and Public Safety Division of Motor Vehicles Trenton, NJ 08666; Thomas L. Wright Acting Manager MVS Customer Services State of New Jersey Department of Law and Public Safety Division of Motor Vehicles Trenton NJ 08666; "Dear Mr. Wright: This responds to your request for information abou responsibilities of motorcycle manufacturers. As you discussed with Dorothy Nakama, the National Highway Traffic Safety Administration (NHTSA) does not 'regulate' how an enterprise becomes a 'recognized manufacturer.' Enclosed is NHTSA's information sheet for new manufacturers of motor vehicles and motor vehicle equipment, which discusses the main requirements of 49 U.S.C. section 30101 et seq. (formerly the Vehicle Safety Act). A copy of the Act is enclosed. Under section 30112(a) of the Act, a motorcycle manufacturer may not manufacture a motorcycle for sale unless the vehicle complies with all applicable Federal Motor Vehicle Safety Standards (FMVSS) and is covered by a certification issued under 49 U.S.C. section 30115. One safety standard is Standard No. 115 Vehicle Identification Number - Basic Requirements. (See 49 CFR 571.115.) In our regulations, at 49 CFR part 567 Certification, NHTSA has promulgated the requirement that a manufacturer certify compliance of its motorcycle with all applicable safety standards. Under part 566, NHTSA requires manufacturers to submit certain identifying information and a description of the items they produce. Also enclosed is a copy of a July 13, 1992 interpretation letter to Mr. Jeffrey Puentes, discussing serial numbers on motorcycle frames versus motorcycle VINs. As you may be aware, 'certificates of origin' are matters relating to vehicle titling, which the State regulates, rather than NHTSA. I hope this information is helpful. If you have any further questions, please contact Ms. Nakama at (202) 366-2992. Sincerely, John Womack Acting Chief Counsel Enclosures"; |
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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.