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: aiam0824OpenMr. Steven M. Sharp, Managing Director, Intercontinental Equipment Corp., 5383 Overland Avenue, San Diego, CA 92123; Mr. Steven M. Sharp Managing Director Intercontinental Equipment Corp. 5383 Overland Avenue San Diego CA 92123; Dear Mr. Sharp: This is in response to your letter of July 27, 1972, in which you rais several questions concerning Part 566, Manufacturer Identification, Part 567, Certification, and Part 568, Vehicles Manufactured in Two or More Stages. You state that Intercontinental Equipment Corp. (I.E.C.) is the United States importer and distributer of certain vehicles manufactured by Suzuki Motor Co., Ltd. in Japan. You also state that I.E.C. has contracted with Yachiyoda Sangyo Co., Ltd. of Tokyo to acquire vehicles from Suzuki, remove non-complying equipment, install approved devices, and affix necessary labels of conformity and arrange for shipment.; The answers to your questions are as follows 1. You ask whether the I.E.C. contract with Yachiyoda changes th status of Suzuki as manufacturer and I.E.C. as importer. It does not change the status with respect to our manufacturer identification and certification regulations.; 2. You inquire as to the classification of Suzuki and Yachiyoda unde Part 568, Vehicles Manufactured in Two or More Stages. Since Suzuki manufactures a completed vehicle, Yachiyoda is not considered a manufacturer under NHTSA regulations and is not required by the NHTSA to submit manufacturer identification or certification information.; 3. You ask whether the label of conformity (Label 2) which you propose to have affixed to the vehicles is acceptable. Th NHTSA finds it acceptable.; I enclose copies of Parts 566, 567, and 568 for your information. Sincerely, Richard B. Dyson, Assistant Counsel |
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ID: aiam1063OpenPaul K. Wilson, Staff Engineer, Truck Trailer Manufacturers Association, 2430 Pennsylvania Avenue, N.W., Washington, DC 20031; Paul K. Wilson Staff Engineer Truck Trailer Manufacturers Association 2430 Pennsylvania Avenue N.W. Washington DC 20031; Dear Mr. Wilson: This is in reply to your letter of March 19, 1973, asking whether towbar dolly must be included in determining the overall length of semitrailers for compliance with Federal Motor Vehicle Safety Standard No. 108.; The answer is no. Standard No. 108 is a manufacturing standard, an semitrailers are not manufactured with dollies attached. 49 CFR S390.7, to which you refer, is a definition of the Bureau of Motor Carrier Safety which regulates the operation of certain motor vehicles, and since trailers often use converter dollies, it is understandable that that agency would deem a trailer with a dolly a 'full trailer.'; Yours truly, Richard B. Dyson, Assistant Chief Counsel |
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ID: aiam0524OpenMr. Albert D. Ekegren, Vice President and General Manager, Cats-Eye Lamp Division, Holophane Company, Inc., Post Office Box 567, Columbus, OH, 43216; Mr. Albert D. Ekegren Vice President and General Manager Cats-Eye Lamp Division Holophane Company Inc. Post Office Box 567 Columbus OH 43216; Dear Mr. Ekegren: This is in response to your letter of December 13, 1971, in which yo made further comments on the requirements of Standard No. 108 with respect to school bus lighting. You expressed concern over the fact that a company holds a patent relating to the wiring for eight-lamp systems that are permitted (though not required) under Standard No. 108.; Although the existence of patents is one factor that may be taken int account in setting motor vehicle safety standards, it is not the primary one. This agency is charged by Congress with the responsibility of setting standards that represent the best possible resolution of the problems of safety, cost, and technological feasibility. If two alternative regulatory courses of action are found to be substantially equal in other respects, the agency might prefer the one in which the largest number of companies were free to compete at will. But the granting of patents is a long-established policy of our government, administered by the U.S. Patent Office under the direction of Federal statutes and the Constitution. We do not, therefore, agree with your suggestion that it is 'against public interest' to issue regulations that have the incidental effect of favoring or requiring the use of patented products.; Sincerely, Lawrence R. Schneider, Chief Counsel |
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ID: aiam0120OpenMr. Berkley C. Sweet, Executive Vice President, Truck Body and Equipment Association, Inc., 1012 Fourteenth Street, N.W., Washington, DC 20005; Mr. Berkley C. Sweet Executive Vice President Truck Body and Equipment Association Inc. 1012 Fourteenth Street N.W. Washington DC 20005; Dear Mr. Sweet: Thank you for your letter of September 12, 1968, to Mr. J. E. Leysat of this Bureau, requesting a clarification of the aiming requirements for school bus signal lamps as specified in Federal Motor Vehicle Safety Standard No. 108.; Paragraph S3.1.3.1 of Standard No. 108 specifies that red school bu signal lamps shall conform to SAE Standard J887, 'School Bus Red Signal Lamps,' July 1964, and that amber signal lamps shall conform to the same SAE Standard except for color and candlepower requirements. In the last paragraph of SAE Standard J887, aiming requirements are specified as follows: 'Lamps should be mounted on the school bus with their aiming plane vertical and normal to the vehicle axis. A suggested tolerance for this aim is 5 inches at 25 feet in vertical aim and 10 inches at 25 feet in horizontal aim. If lamps are aimed or inspected with a mechanical headlamp aimer (see SAE J602) the graduation settings for aim should be 2 down and 0 sideways. The limits for inspection should be from 3 up to 7 down and from 10 right to 10 left.'; In accordance with the above quoted paragraph, either visual o mechanical aiming of the signal lamps is permitted. Therefore, the graduation settings and inspection limits, as specified in the last two sentences of the paragraph, are applicable only when a mechanical headlamp aimer is used to aim the signal lamps.; Thank you for writing. Sincerely, Charles A. Baker, Office of Standards on Accident Avoidance Motor Vehicle Safety Performance Service; |
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ID: aiam3391OpenMs. Mary Donovan, 51 Earl Street, Springfield, MA 01108; Ms. Mary Donovan 51 Earl Street Springfield MA 01108; Dear Ms. Donovan: This is in response to your letter of January 28, 1981 concerning th problems you've experienced with the odometer in your car.; The Motor Vehicle Inforamtion and Cost Savings Act (15 U.S.C. S198 *et. seq*) prohibits the disconnection, resetting, or alteration of a vehicle's odometer with the intent to change the number of miles indicated therein. The law also requires that a written disclosure of the mileage registered on an odometer be provided by the seller to the purchaser at the time the ownership of a vehicle is transferred. If the odometer mileage is incorrect, the Act requires a statement to that effect to also be furnished in written form to the buyer.; This disclosure can be made on the state's certificate of title if th certificate of title contains essentially the same information found in the Federal odometer disclosure statement. *Odometer Disclosure Requirements* (49 CFR Part 580.4(f)(1). The odometer statement on the Massachusetts certificate of title is consistent with the requirements of the Federal law and can be substituted for the Federal form. All of the other provisions of the Federal odometer laws are applicable in Massachusetts.; Accordingly, if the odometer is incapable of registering the *sam mileage after its repair or replacement, a notice in writing should be attached to the left door frame of the vehicle by the owner specifying the date the odometer was repaired or replaced and the mileage at that time. However, since you did not indicate the odometer reading was *reset*, this provision does not appear to be applicable to your case.; Sincerely, Shirley Ransom, Trial Attorney |
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ID: aiam1272OpenHonorable Quentin N. Burdick, United States Senate, Washington, DC 20510; Honorable Quentin N. Burdick United States Senate Washington DC 20510; Dear Senator Burdick: This is in further reply to your letter of September 7, 1973 concerning correspondence you received from Mr. Alton R. Rau of Linton, North Dakota. Mr. Rau objects to Federal regulations which require him to purchase trucks with stronger axles and tires than those trucks which he formerly purchased.; The National Highway Traffic Safety Administration Certificatio regulations (49 CFR Parts 567 and 568) require manufacturers to establish gross vehicle and gross axle weight ratings, and to equip new vehicles with components, including tires and axles, that are of sufficient capacity to carry intended loads. The regulations do not establish the relevant ratings, which are established solely by manufacturers. We feel the justification in terms of safety for such requirements is obvious.; We believe situations such as that experienced by Mr. Rau where according to manufacturer's figures, vehicles should have been equipped with stronger axles and tires, demonstrate the need for the Certification requirements rather than showing them to be unnecessary.; The regulations apply only to new motor vehicles, and not to vehicle already in use. For Mr. Rau's information I have enclosed a copy of these requirements.; Sincerely, Robert L. Carter, Associate Administrator, Motor Vehicl Programs; |
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ID: aiam1274OpenHonorable Quentin N. Burdick, United States Senate, Washington, DC 20510; Honorable Quentin N. Burdick United States Senate Washington DC 20510; Dear Senator Burdick: This is in further reply to your letter of September 7, 1973 concerning correspondence you received from Mr. Alton R. Rau of Linton, North Dakota. Mr. Rau objects to Federal regulations which require him to purchase trucks with stronger axles and tires than those trucks which he formerly purchased.; The National Highway Traffic Safety Administration Certificatio regulations (49 CFR Parts 567 and 568) require manufacturers to establish gross vehicle and gross axle weight ratings, and to equip new vehicles with components, including tires and axles, that are of sufficient capacity to carry intended loads. The regulations do not establish the relevant ratings, which are established solely by manufacturers. We feel the justification in terms of safety for such requirements is obvious.; We believe situations such as that experienced by Mr. Rau where according to manufacturer's figures, vehicles should have been equipped with stronger axles and tires, demonstrate the need for the Certification requirements rather than showing them to be unnecessary.; The regulations apply only to new motor vehicles, and not to vehicle already in use. For Mr. Rau's information I have enclosed a copy of these requirements.; Sincerely, Robert L. Carter, Associate Administrator, Motor Vehicl Programs; |
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ID: aiam1954OpenMr. John M. Whalen, Platz & Thompson, 183 Main Street, Lewiston, Maine 04240; Mr. John M. Whalen Platz & Thompson 183 Main Street Lewiston Maine 04240; Dear Mr. Whalen: This is in response to your letter of May 13, 1975 requesting information concerning standards that relate to the installation of campers on pick-up trucks and the modification of such pick-up trucks to accommodate the camper bodies.; With regard to camper manufacture, your client must meet th requirements of Standard No. 126, *Truck-camper loading*, if he manufactures slide-in campers. In addition, since your client in engaged in the modification of a pick-up trucks, he should be aware, not only of the certification and multistage vehicle manufacturing regulations (49 CFR Parts 566, 567, and 568), but of all safety standards that are applicable to that type of vehicle (39 CFR Part 571).; If the pick-up trucks on which your client installs the campers are ne (have not yet been sold for purposes other than resale), your client would have to comply with the safety standards and the certification regulations in altering the truck-camper for sale. If the pick-up trucks are used vehicles, Section 108 of the National Traffic and Motor Vehicle Safety Act as amended(Pub. L. 93-492) prohibits the rendering inoperative of any system installed in compliance with an applicable motor vehicle safety standard. For this reason, your client should be aware of the motor vehicle safety standards that apply to pick-up trucks.; I have enclosed a sheet entitled 'Where to Obtain Motor Vehicle Safet Standards and Regulations' which will direct you to the proper source for procuring copies of the relevant standards and regulations.; Sincerely, James C. Schultz, Chief Counsel |
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ID: aiam5609OpenMr. Michael A. Knappo 380-1A Hartford Road Amherst, NY 14226; Mr. Michael A. Knappo 380-1A Hartford Road Amherst NY 14226; Dear Mr. Knappo: This is in response to your letter regarding a produc that you wish to offer for sale in the near future. You have asked for information on how this product might be affected by local and national laws. According to your letter, 'Auto Ad' is a portable advertising unit that is designed with a flexible screen that can be secured to a window with suction cups. The screen is illuminated with LEDs, controlled by a key pad mounted close to the driver. The unit will run off power from the car battery through the cigarette lighter, or 'hardwired in.' The diagram you enclosed shows 'Auto Ad' mounted in the rear side window of a car and a van. While we do not have information about State or local laws, I am enclosing copies of several letters we have issued in recent years concerning the applicability of Federal law to products which appear to be similar to yours (addressed to Mr. Shawn Shieh, dated June 8, 1993, Mr. Chris Lawrence, dated May 10 and March 21, 1991, Mr. Alan Eldahr, dated August 17, 1989, and Mr. Don Benfield, dated July 8, 1985). I hope this information is helpful. If you have any further questions, you may call Taylor Vinson of this Office (202-366-5263). Sincerely, John Womack Acting Chief Counsel Enclosures; |
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ID: aiam1648OpenMr. John C. Hansen, Sales Manager, Columbia Body & Equipment Co., 123 N. E. Oregon Street, Portland, OR 97232; Mr. John C. Hansen Sales Manager Columbia Body & Equipment Co. 123 N. E. Oregon Street Portland OR 97232; Dear Mr. Hansen: This responds to CBE's October 24, 1974, question whether a traile equipped with a telescoping drawbar that varies the distance between axles to conform to various State regulations would qualify as a 'Heavy hauler trailer' as that term is defined in Standard No. 121, *Air brake systems*:; >>>'Heavy hauler trailer' means a trailer with one or more of th following characteristics:; (1) Its brake lines are designed to adapt to separation or extension o the vehicle frame, or; (2) Its body consists only of a platform whose primary cargo-carryin surface is not more than 40 inches above the ground in an unloaded condition, except that it may include sides that are designed to be easily removable and a permanent 'front-end structure' as that term is used in S 393.106 of this title.<<<; The answer to your question is no. The extension of the drawbar is no an 'extension of the vehicle frame.' This characteristic is intended only to describe trailers whose function necessitates a highly specialized configuration that significantly interferes with brake design. In contrast the telescoping drawbar is not related to the trailer's function, but simply permits the vehicle to conform to State highway regulations.; Yours truly, Richard B. Dyson, Acting Chief Counsel |
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.