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: aiam0342OpenMr. Keitaro Nakajima, General Manager, Toyota Motor Company, Ltd., Factory Representative Office, Lyndhurst Office Park, 1099 Wall Street West, Lyndhurst, NJ 07071; Mr. Keitaro Nakajima General Manager Toyota Motor Company Ltd. Factory Representative Office Lyndhurst Office Park 1099 Wall Street West Lyndhurst NJ 07071; Dear Mr. Nakajima:#This is in reply to your letter of April 1 seeking clarification of paragraph S4.1.2 of Motor Vehicle Safety Standard No. 104.#We confirm your understanding that S4.1.2 excludes any part of wiped areas A, B, and C that lie outside the perimeter line. Change of your driver's seating reference point to meet the proposed requirements of Standard No. 201 does not affect the percentage of area A, assuming no change in the perimeter line.#Sincerely, Lawrence R. Schneider, Acting Chief Counsel; |
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ID: aiam5510OpenMr. Donnell W. Morrison 1005 Drinnon Drive Morristown, TN 37814; Mr. Donnell W. Morrison 1005 Drinnon Drive Morristown TN 37814; Dear Mr. Morrison: We have received your letter of March 14, 1995 an its attached copy of a letter dated February 14. I am sorry to say that your earlier letter never reached us. You asked whether the mounting height requirements for clearance and identification lamps (Table II of Motor Vehicle Safety Standard No. 108) have been amended to allow their mounting in locations other than 'as high as practicable.' The requirements have not changed since you were at DOT. The primary requirement is that identification lamps are to be mounted 'as close to the top of the vehicle as practicable', and that clearance lamps are mounted 'to indicate the overall width of the vehicle . . . as near the top thereof as practicable.' The determination of practicability is initially that of the manufacturer, to be made in its certification that the vehicle meets all applicable Federal motor vehicle safety standards. NHTSA will not question that determination unless it appears clearly erroneous. However, when the rear identification lamps are mounted at the extreme height of the vehicle, paragraph S5.3.1.4 states that the rear clearance lamps need not be located as close as practicable to the top of the vehicle. Further, if it is necessary to indicate the overall width of the vehicle, or for protection from damage during normal operation of the vehicle, clearance lamps may be mounted at a location other than on the front and rear and need not be visible at 45 degrees inboard (paragraph S5.3.1.1.1). Sincerely, Philip R. Recht Chief Counsel; |
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ID: aiam1800OpenMr. Murray Bartlett, B. F. Goodrich Tire Co., 500 South Main Street, Akron, OH 44318; Mr. Murray Bartlett B. F. Goodrich Tire Co. 500 South Main Street Akron OH 44318; Dear Mr. Bartlett: This letter reviews for conformity with statutory requirements a draf defect notification letter received by my office regarding Goodrich's impending notification campaign for tires retreaded by B. F. Goodrich using carcasses branded 'General Belted Jumbo 780.'; As you are aware, defect notifications issued on or after December 26 1974, are required to comply with the requirements in section 153 of the 1974 amendments to the National Traffic and Motor Vehicle Safety Act (Public Law 93-492, 88 Stat. 1470). We have the following changes to recommend in your draft notification.; Section 153(a)(5) requires the notification to specify 'the earlies date . . . on which such defect or failure to comply will be remedied without charge, and in the case of tires, the period during which such defect or failure to comply will be remedied without charge . . .' We believe this requirement should be met by specifying the actual earliest date by which dealers will have necessary replacement parts and instructions, and by informing owners that they have 60 days from that date (or 60 days from the day they receive the notification, whichever is later) to obtain replacement free of charge.; You must also include information that is responsive to sectio 153(a)(6). As the procedures referred to in that section have not been published, it is sufficient if you advise owners that they may write to the Administrator, National Highway Traffic Safety Administration, Washington, D.C. 20590, if they find B. F. Goodrich, its distributors, or dealers, to have failed or to have been unable to perform the replacement satisfactorily.; In other respects we find your letter to conform to the statutor requirements.; Yours truly, James C. Schultz, Acting Chief Counsel |
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ID: aiam0712OpenMr. Clyde Parrott, Design Engineer, Hamilton Cosco, Inc., State Street, Columbus, IN 47201; Mr. Clyde Parrott Design Engineer Hamilton Cosco Inc. State Street Columbus IN 47201; Dear Mr. Parrott: This is in reply to your letter of May 4, 1972, posing certai questions concerning paragraph S4.10 of Motor Vehicle Safety Standard No. 213, 'Child Seating Systems.' You ask 'what criteria are to be used to determine whether an area is a contactable area under S4.10.'; The components that would be considered contactable by the head unde S4.10.1, or by the torso under S4.10.2, are any components which a child within the weight and height range for which the seat is recommended might contact in a 30 m.p.h. barrier crash, as represented by the test procedure specified in S5.1 and S5.2.; You also ask for clarification of the meaning of 'rigid side' as tha phrase is used in S4.10.3. As we indicated to you in our letter of February 23, 1972, manufacturers should rely on generally available definitions of 'rigid' in determining whether or not components are within the term. The reference to 'side' includes components placed both to the right and left, and forward of and behind the child occupant. Consequently, both an arm rest and a head rest (either separate from the back of a child seat or part of a one piece back of a child seat) could fall within the exemption of S4.10.3. The reference to 'back or side' in the proposed amendment to S4.10 published September 23, 1972 (35 F.R. 14786), is intended purely as a clarification of the existing language, the main thrust of the proposed revision would be, as stated in its preamble, to eliminate the exemption in the head- contact area.; With reference to the status of the September 23 proposal, a final rul based on this notice is still under consideration and we cannot presently provide an indication as to when it may become effective.; Yours truly, Richard B. Dyson, Assistant Chief Counsel |
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ID: aiam4751OpenThe Honorable Lawrence J. Smith U. S. House of Representatives Washington, D.C. 20515; The Honorable Lawrence J. Smith U. S. House of Representatives Washington D.C. 20515; "Dear Mr. Smith: I am writing in response to your letter forwardin correspondence from your constituent, Mr. Joel Leitson, with respect to litigation recently brought by the United States against several firms that install plastic film, or 'tint,' on automobile windows. You have asked about the statutory authority under which these suits were brought. Pursuant to section 103 of the National Traffic and Motor Vehicle Safety Act of 1966 ('Safety Act'), 15 U.S.C. 1392, the National Highway Traffic Safety Administration ('NHTSA') has issued safety standards applicable to new motor vehicles and items of motor vehicle equipment. One of the standards that we have issued under this authority is Federal Motor Vehicle Safety Standard No. 205, Glazing Materials (49 CFR 571.205), which applies to all new vehicles and all new glazing materials for use in motor vehicles. Among the requirements set forth in Standard No. 205 are specifications for minimum levels of light transmittance (70 percent light transmittance in areas requisite for driving visibility, which includes all windows in passenger cars). Section 108(a)(i)(A) of the Safety Act, 15 U.S.C. 1397(a)(1)(A), provides that no person may manufacture or sell any vehicle unless it is in conformity with all applicable safety standards. Pursuant to section 108(b)(1) of the Safety Act, 15 U.S.C. 1397(b)(1), this paragraph does not apply after a vehicle is first sold to a consumer. However, both before and after the first sale, section 108(a)(2) of the Safety Act, 15 U.S.C. 1397(a)(2), provides that '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 . . . .' Thus, by installing tint film on automobiles that reduces the light transmittance of their glass below 70 percent, the firms in question have been rendering those vehicles 'inoperative,' in violation of the Safety Act. The same principle would apply to a service station that removed an airbag or a safety belt from a vehicle, since such an action would create a noncompliance with the occupant protection requirements of NHTSA's standards. You also asked for our comments on whether Florida's statutes are preempted by these suits. We assume that you are referring to the provision of Florida law that prohibits the operation of any vehicle in the State of Florida that has glazing with less than 35 percent light transmittance. This statute, and similar statutes adopted by other states, do not purport to legitimize conduct -- the rendering inoperative of glazing by tint installation firms -- that is illegal under the Safety Act. Thus, there is no conflict with Federal law, and Florida may continue to enforce its operating rules. I hope that this responds to your questions. If we can be of further assistance, please let me know. Sincerely, Paul Jackson Rice Chief Counsel"; |
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ID: aiam3094OpenMr. R. M. Premo, Director, Vehicle Safety Activities, Sheller-Globe Corporation, 3555 St. Johns Road, Lima, OH 45804; Mr. R. M. Premo Director Vehicle Safety Activities Sheller-Globe Corporation 3555 St. Johns Road Lima OH 45804; Dear Mr. Premo: This responds to your August 27, 1979, letter asking how the agenc tests a floor joint for compliance with Standard No. 221, *School Bus Body Joint Strength*. You enclosed a sketch and sample floor joint with your letter and asked in which direction the forces would be applied for test purposes. You suggested that the forces be applied in a perpendicular direction to the floor.; The floor joint that you manufacture is welded in three locations. On weld is located on top of the floor surface and joins the two panels together. The agency concludes that this joint should be tested by applying force in a direction that is parallel to the floor surface, not perpendicular to it. This is the procedure that is specified in section S6 of the standard for testing joints that are constructed in a manner similar to the floor joint in your vehicle.; Sincerely, Frank Berndt, Chief Counsel |
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ID: aiam1553OpenMr. John W. Lolley, Lolley's Inc., Long Hill Road, Gray, ME 04039; Mr. John W. Lolley Lolley's Inc. Long Hill Road Gray ME 04039; Dear Mr. Lolley: Thank you for your letter of July 15, 1974, concerning you responsibilities as a manufacturer.; Since you shorten frames and mount fifth wheels on new trucks, you ar either an intermediate or final stage manufacturer. I have enclosed Parts 566, 567, 568, and 573 for your information. In addition, I have enclosed a form, entitled 'Federal Motor Vehicle Safety Standards and Regulations' that will enable you to obtain these documents.; If you have any questions on the above, please write me or call Mr David Fay, of my staff, on (202) 426-2817.; Sincerely, Roger H. Compton, Director, Engineering Systems Staff, Moto Vehicle Programs; |
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ID: aiam4301OpenMr. Wil de Groot, President, Exoticars of Hunterdon, 6 Washington Street, Frenchtown, NJ 08825; Mr. Wil de Groot President Exoticars of Hunterdon 6 Washington Street Frenchtown NJ 08825; Dear Mr. de Groot: This is in reply to your letter of April 2, 1987, with respect to you further questions on Federal regulations of kit cars.; You have presented the following facts: the engine, transmission, fina drive, axles, suspension, steering, brakes, heating and defrosting equipment, windshield wiper motor and mechanisms, instruments, switches, controls, wiring harness, fuel tank, seat belts, door and ignition switch buzzer system, door handles, latches and locks, impact absorbing bumper supports, and other unnamed components, all previously used on a vehicle meeting Federal safety standards would be retained for use with a new body of your own manufacture.; Your first choice is to install these items upon a new chassis of you own manufacture, and to supply the vehicle to a purchaser fully assembled. This is what must be met under these circumstances: when a new body is mounted upon a new chassis, the resulting vehicle must comply with all Federal motor vehicle safety standards applicable upon the date of its assembly, even if the parts that you named are used. Further, the assembler must certify that the vehicle complies with the safety standards. There is no legal obligation to use new parts in order to certify compliance with the standards. The assembler is regarded as a manufacturer of motor vehicles, and must notify owner and remedy noncompliance with the safety standards or safety related defects should they occur, in accordance with Federal law and regulations.; If you supply all parts, but do not complete assembly of the vehicle we would regard you nevertheless as its manufacturer and subject to the requirements stated above. However, if you do not supply all parts, the question of whether you would be regarded as the manufacturer would necessarily depend upon the parts that the purchaser must supply in order to complete assembly.; You have also stated your second choice: that the new body would b mounted upon the original chassis, modified to accept it. In this circumstance, when a new body is mounted upon a used chases, the resulting vehicle is not subject to the Federal motor vehicle safety standards that apply to new vehicles, and there is no certification obligation. Nevertheless, its assembler is a 'manufacturer' under Federal law and responsible for notification of owners and remedy of any safety related defects that may occur in the product. Further, if the safety related defects that may occur in the product. Further, if the assembler is the person responsible for removing the old body, he must ensure that the reassembled vehicle continues to meet the standards that originally applied to the vehicle which might have been affected by removal of the old body. For example, if the body of a 1974 Jaguar XJ6 is removed, compliance with a number of standards such as those covering glazing, lighting, and windshield retention is affected and the reassembled vehicle must then meet the standards that were in effect in 1974. But, standards covering such things as accelerator control systems and brake hoses would not appear to be affected by the disassembly of the original vehicle, and the assembler is under no obligation to ensure that the reassembled vehicle continues to meet those standards.; If the used-chassis vehicle is supplied partially disassembled, but al parts are supplied, we would nevertheless regard the supplier as subject to all the obligations discussed above, assuming that he was the person responsible for removal of the old body. If all parts are not supplied, the answer remains as before: whether the supplier is a 'manufacturer' depends upon the parts that the purchaser must provide.; Finally, you have asked, 'if actual crash tests...have to be made wha is the cost and where is this done?' There is no express legal requirement that a manufacturer of new motor vehicles conduct crash tests in order to certify compliance with those standards where compliance can be demonstrated through barrier impacts. A manufacturer is required to exercise due care to ensure that his vehicle, if crashed, would meet the performance requirements of those standards incorporating barrier impact test procedures, but his certifications may be based upon computer simulations, engineering studies, mathematical calculations, etc. We cannot advice you as to the cost of such tests, and suggest you write the Motor Vehicle Manufacturers Associations (MVMA) for information on facilities that perform them. MVMA's address is 1620 I Street, N.W., Washington, D.C.; I hope that this answers you questions. Sincerely, Erika Z. Jones, Chief Counsel |
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ID: aiam1103OpenMr. Ralph H. Ullenberg, President, Milwaukee truck Center, Inc., 10521 West Layton Avenue, Milwaukee, WI 53228; Mr. Ralph H. Ullenberg President Milwaukee truck Center Inc. 10521 West Layton Avenue Milwaukee WI 53228; Dear Mr. Ullenberg: This is in reply to your letter of March 6, 1973, in which you as several questions regarding the certification of trucks with concrete mixers. You state that you supply a chassis to the Rex Chainbelt factory in Milwaukee, where a concrete mixer is installed. The combined unit is then shipped to a Rex dealer in Puerto Rico who sells the complete unit to a user. You provide weight ratings for the vehicle as follows: a gross vehicle weight rating, based on axle capacity, of 68,000 pounds, a rating, based on the tire capacity, of 56,740 pounds, and a gross weight of 66,800 pounds. Based on these figures you ask (1) Whether the truck can be completed in this fashion and shipped by you to Puerto Rico, (2) Whether the dealer in Puerto Rico can promise to install larger tires at a later date, (3) Whether Rex Chainbelt can certify the chassis at 68,000 pounds gross weight rating, if the dealer in Puerto Rico notifies Rex that he will change the tires at a later date, (4) Whether the chassis manufacturer can certify the truck chassis for a greater capacity than the lightest component if the local dealer or customer will notify him that they will bring the chassis to the higher certified level, and (5) What penalties can be imposed if a dealer or user does not make changes he has promised to make.; It appears to us from your letter that essentially the same issu underlies all your questions, that is, whether a final- stage manufacturer in completing a vehicle may place on it tires that are not sufficient to carry the vehicle at its gross vehicle weight rating, and elicit a promise from either a dealer or user that the latter will change the tires.; A truck that is equipped at the time of its manufacture with tire inadequate in terms of load rating to carry the truck at its gross vehicle weight rating would be considered by NHTSA to contain a safety related defect. The manufacturer of such a vehicle is subject to the provisions of section 113 of the National Traffic and Motor Vehicle Safety Act (15 U.S.C. 1402), which requires that notification of the defect be sent to first purchasers and dealers. A truck which was labeled with a gross vehicle weight rating below the minimum specified in 49 CFR 567(g)(3) would be in violation of the Certification regulations, and the person affixing such a label would be subject to civil penalties and other sanctions pursuant to section 108, 109, and 110 of the Safety Act (15 U.S. C. 1397, 1398, 1399). The Certification regulations (49 CFR Parts 567, 568) require weight ratings, in cases of vehicles manufactured in two or more stages, to be based on the vehicle as completed by the final-stage manufacturer. That manufacturer is not permitted to delegate his responsibility to a dealer or user.; The NHTSA has made an exception in the case of vehicles shipped withou tires, or vehicles shipped with temporary tires that are not intended to be used on the vehicle apart from the limited purpose of shipment. Your letter contains no implication that your case in within this exception.; Yours truly, Richard B. Dyson, Assistant Chief Counsel |
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ID: aiam1416OpenMr. Thomas S. Pieratt, Truck Equipment & Body Distributors, 602 Main Street, Cincinnati, OH 45202; Mr. Thomas S. Pieratt Truck Equipment & Body Distributors 602 Main Street Cincinnati OH 45202; Dear Mr. Pieratt: This is in reply to your letter of December 18, 1973, inquiring whethe a manufacturer would be an intermediate or final-stage manufacturer if he installs truck bodies or material handling devices (frequently final-stage manufacturing operations) but he expects that a later manufacturer will either extend the chassis frame or add a third axle. These additions are necessary to make the vehicle safe to operate.; In most cases, we would consider the manufacturer in question to be a intermediate manufacturer. Under the definitions of 'completed vehicle,' 'intermediate manufacturer,' and 'final-stage manufacturer' (49 CFR 568.3), the manufacturer would be a final-stage manufacturer only if, at the time he completes his manufacturing operation, the vehicle requires no further manufacturing to perform its intended function, unless the further manufacturing involves only 'readily-attachable components.'; In the case you present, the vehicle cannot perform its intende function unless further modifications are made. That it be able to perform its intended function implies that it be able to do so safely. The answer ultimately depends, therefore, on whether the additions that will be made to the vehicle involve only readily attachable components. We would not generally consider either an extension of the chassis or the addition of a third axle to involve only readily attachable components.; Of course, in those cases where no further modifications are necessar for safe operation, the crane or body installer will be the final-stage manufacturer.; Yours truly, Richard B. Dyson, Assistant 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.