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 |
|---|---|
ID: aiam3760OpenMr. Steve Lampeas, 117 Aldershot Lane, Manhasset, NY 11030; Mr. Steve Lampeas 117 Aldershot Lane Manhasset NY 11030; Dear Mr. Lampeas: This is in reply to your letter of October 13, 1983, concerning th legality under Federal laws of your patented device, the 'Trunk Truck.' It appears from the material you enclosed that the device extends in twin booms from the rear of the car, and that a stop lamp or taillamp is mounted at the end of each boom (you refer to it as a 'natural extension' of these lamps).; Under the National Traffic and Motor Vehicle Safety Act, no perso (except the vehicle owner) may modify a vehicle so that equipment that is on the vehicle pursuant to a Federal motor vehicle safety standard is 'rendered inoperative in whole or in part.' Therefore, you must assure yourself that all requirements of Federal Motor Vehicle Safety Standard No. 108 continue to be met with respect to rear lighting. This would include not only the lamps at the end of the booms, but those remaining on the car. In addition to stop lamps and taillamps, rear lighting includes, (sic) turn signal lamps, back up lamps, and license plate lamps. As on other load-bearing vehicles, such as boat trailers, these lamps should continue to be visible even with a load installed.; You should also ask the States whether such a device is legal. State have jurisdiction over the use of motor vehicles within their borders.; Sincerely, Frank Berndt, Chief Counsel |
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ID: aiam2872OpenMr. Charles J. Kerr, Southwest Research Institute, 6220 Culebra Road, Post Office Drawer 28510, San Antonio, TX 78284; Mr. Charles J. Kerr Southwest Research Institute 6220 Culebra Road Post Office Drawer 28510 San Antonio TX 78284; Dear Mr. Kerr: This responds to your June 27, 1978, letter concerning the requirement of Safety Standard No. 207 as they would apply to pedestal seat assemblies for use in van vehicles. You ask whether your test methodology is consistent with the requirements of the standard and whether the pedestal base is considered part of the seat assembly.; As you know, the agency does not approve a manufacturer's test methods A manufacturer must exercise due care to ascertain that his product is in compliance with all applicable motor vehicle safety standards and regulations. While your test methods appear to be reasonable, the agency will test seats in the vehicle rather than on a surrogate test frame. You must exercise due care to assure that your simulated test is a true determination whether the seats would comply with the standard when tested as provided in that standard. (The vehicle manufacturer is, of course, responsible for compliance with Standard 207.); Regarding your second question, the pedestal base would be considere part of the seat assembly for purposes of Standard 207. This means that the agency would test the entire assembly by applying a force of 20 times the combined weight of the seat and the pedestal, contrary to your simulated test procedure of using only the weight of the seat frame and adjuster, without the pedestal base attached.; Finally, the force requirements of Safety Standard No. 210, *Seat Bel Assembly Anchorages*, (5,000 pounds) are applied simultaneously with the force requirements in Standard No. 207, if the anchorages are connected to the vehicle seat, to the pedestal, or to the pedestal base.; Please contact this office if you have any further questions, an please excuse the delay in this response.; Sincerely, Joseph J. Levin, Jr., Chief Counsel |
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ID: aiam1248OpenMr. Delbert A. Russell, Jr., Auto Safety Research Center, 613 Oak Street, Columbus, OH 43216; Mr. Delbert A. Russell Jr. Auto Safety Research Center 613 Oak Street Columbus OH 43216; Dear Mr. Russell: This is in response to your letter of June 27, 1973, which request information on the requirements of Standard 206, *Door Locks and Door Retention Components*, and suggests that door locking mechanisms should prevent operation of the inside and outside handles (latch release controls) of both front and rear doors.; The standard presently requires that engagement of the front-doo locking mechanism on passenger cars, multi-purpose passenger vehicles, and trucks render the outside door handle (latch release control) inoperative. On passenger cars and multipurpose passenger vehicles, engagement of the rear- door locking mechanism must render both inside and outside handles inoperative. Your suggestion that inside door handles also be rendered inoperative was proposed in 1967 as an initial standard, but it was determined at that time that ease of escape in the event of accident made one-step operation of the door more desirable. It was concluded that the vehicle operator would have sufficient control over children in the front seat to permit such override operation.; We are still interested in the best arrangement of locking mechanism and override at the various seating positions. At the moment, available accident data does not justify further rulemaking. Your comments will be fully considered in the event we decide to take further action.; Yours truly, Richard B. Dyson, Assistant Chief Counsel |
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ID: aiam3275OpenMr. Philip J. Carpenter, Administrative Engineer, Miller Tilt-Top Trailer, Inc., 450 S. 992 Street, P.O. Box 14247, Milwaukee, Wisconsin 53214; Mr. Philip J. Carpenter Administrative Engineer Miller Tilt-Top Trailer Inc. 450 S. 992 Street P.O. Box 14247 Milwaukee Wisconsin 53214; Dear Mr. Carpenter: This is in response to your letter of April 2, 1980, in which yo request approval for the vehicle identification numbering (VIN) system Miller Tilt-Top Trailer, Inc., proposes to use to satisfy the requirements of Federal Motor Vehicle Safety Standard 115 (49 CFR 571.115).; The National Highway Traffic Safety Administration does not approve manufacturer's compliance with the safety standard, as manufacturers serve as self-certifiers under the National Traffic and Motor Vehicle Safety Act. However, my office has reviewed your proposed system. Based on our understanding of the information that you have provided, your system apparently complies with Standard No. 115. We would also recommend that when you submit information to the agency pursuant to S6 of the standard, you follow each 'series' designation (4th and 5th characters of the VIN) with the phrase 'rectangular, flat platform trailer and body.'; Sincerely, Frank Berndt, Chief Counsel |
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ID: aiam1618OpenMr. K. Nakajima, Director/General Manager, Toyota Motors Sales, U.S.A., Inc., Lyndhurst Office Park, 1099 Wall Street, West, Lyndhurst, NJ 07071; Mr. K. Nakajima Director/General Manager Toyota Motors Sales U.S.A. Inc. Lyndhurst Office Park 1099 Wall Street West Lyndhurst NJ 07071; Dear Mr. Nakajima:#This is in response to your letter of September 9 1974, requesting an interpretation of Federal Motor Vehicle Safety Standard No. 101, specifically, whether Toyota should identify controls with words as well as symbols.#Your use of symbols alone, without the words specified in Column 2 of Table 1 to identify the headlamp, hazard warning, and washer/wiper controls on the 1974 Corona model, is not in compliance with the standard. Symbols are merely an option which may be used in addition to the mandatory word identification.#I have forwarded a copy of your letter to the NHTSA Office of Standard Enforcement, for such action as it deems necessary.#Your truly, Richard B. Dyson, Acting Chief Counsel; |
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ID: aiam3625OpenConfidential; Confidential; Dear Confidential: This is in reply to your letter of October 15, 1982, asking for a interpretation of Motor Vehicle Safety Standard No. 123, *Motorcycle Controls and Displays*. You have asked whether the standard permits three-wheeled motorcycles to be equipped with a reverse gear.; Standard No. 123 applies only to motorcycles with handlebars, which ar generally those machines with two wheels. As the standard is silent with respect to reverse gears, the agency considers that a manufacturer of a three-wheeled motorcycle with handlebars may provide and locate a reverse gear change mechanism wherever he deems appropriate.; This office can offer no comments on three-wheeled motorcycle safety i general. However, I suggest that you contact NHTSA's Office of Research and Development. Several years ago it conducted a study of three-wheeled vehicles, and as I recall, a configuration with two wheels in front and one behind was found to offer greater stability than the converse.; We shall delete your name and that of your company from the publicl available copies of this letter, in accordance with your wish for confidentiality.; Sincerely, Frank Berndt, Chief Counsel |
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ID: aiam2937OpenMr. James R. Randolph, 765 Malley Drive, Northglenn, CO 80233; Mr. James R. Randolph 765 Malley Drive Northglenn CO 80233; Dear Mr. Randolph: This responds to your December 28, 1978, letter concerning an auxiliar fuel tank installed by the dealer on a 1978 Ford van that you purchased. You are concerned that the auxiliary tank represents a safety hazard due to the location of the tank's filler cap in the left rear wheel-well.; Federal Motor Vehicle Safety Standard No. 301-75, *Fuel Syste Integrity* specifies performance requirements for fuel systems on motor vehicles. Although the standard applies to completed vehicles rather than to fuel tanks or other fuel system components, your dealer had to assure that your van complied with the standard. A person who mounts an auxiliary fuel tank on a new motor vehicle before the vehicle's first purchase in good faith for purposes other than resale is a vehicle alterer under National Highway Traffic Safety Administration regulations. That person is required by 49 CFR 567.7 to affix a label to the vehicle stating that, as altered, the vehicle conforms to all applicable Federal motor vehicle safety standards--including Safety Standard No. 301-75. Therefore, there should be an 'alterer' label on your van in addition to the certification label placed on the vehicle by the original manufacturer.; Even if the vehicle complies with Safety Standard No. 301-75, th location and design of the auxiliary fuel tank could constitute a safety-related defect for which the manufacturer would also be responsible. I am, therefore, forwarding a copy of your letter to the agency's Office of Defects Investigation. That office will examine this situation and may be in touch with you at a later date.; Thank you for your letter and for bringing this matter to ou attention.; Sincerely, Joseph J. Levin, Jr., Chief Counsel |
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ID: aiam4949OpenMr. Woodruff Carroll Carroll, Carroll, Davidson, & Young The White Memorial Building Suite 206 100 East Washington St. Syracuse, NY 13202; Mr. Woodruff Carroll Carroll Carroll Davidson & Young The White Memorial Building Suite 206 100 East Washington St. Syracuse NY 13202; "Dear Mr. Carroll: This responds to your letter inquiring about ho NHTSA's regulations relate to snowplows. Ms. Kathleen DeMeter, the Assistant Chief Counsel for General Law, has already responded to your Freedom of Information request in a letter dated January 6, 1992. I am pleased to have this opportunity to further explain our regulations to you. By way of background information, the National Traffic and Motor Vehicle Safety Act (the Safety Act, 15 U.S.C. 1392) authorizes this agency to issue Federal motor vehicle safety standards that set performance requirements for new motor vehicles and new items of motor vehicle equipment. A snow plow that is designed and intended to be attached to a motor vehicle would be considered an item of motor vehicle equipment, within the meaning of the Safety Act. However, NHTSA has not issued any specific standards setting forth performance requirements for snow plows. While there are no safety standards directly applicable to snow plows, the following circumstances are relevant to equipping motor vehicles with snow plows. If before the first consumer purchase, the original equipment manufacturer or an alterer equips a motor vehicle with a snow plow, the manufacturer or alterer must certify that the vehicle complies with the applicable safety standards when equipped with the snow plow. This leads to the question of what conditions would be used to determine if the vehicle complies with the applicable safety standards when equipped with a snow plow. This question is answered in the definition of 'unloaded vehicle weight' set forth in 49 CFR 571.3. 'Unloaded vehicle weight,' which is used to determine a vehicle's gross vehicle weight rating for the purposes of the tire and braking standards and to specify the test conditions for NHTSA's crash testing standards, is defined as 'the weight of a vehicle with maximum capacity of all fluids necessary for operation of the vehicle, but without cargo, occupants, or accessories that are ordinarily removed from the vehicle when they are not in use.' Thus, those parts of the snow plow which are permanently attached to the vehicle and any snow plow parts that are not ordinarily removed from the vehicle would be in place and their weight would be considered in determining compliance with applicable standards. However, the snow plow blade and any other parts of the snow plow that are ordinarily removed when the snow plow is not in use would not be attached to the vehicle and the weight of these parts would not be considered in determining compliance with the applicable safety standards. Another relevant provision of Federal law with respect to equipping a vehicle with a snow plow is 108(a)(2)(A) of the Safety Act (15 U.S.C. 1397(a)(2)(A)), which specifies that, 'no manufacturer, distributor, dealer, or motor vehicle repair business shall knowingly render inoperative, in whole or in 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.' If a manufacturer, distributor, dealer, or motor vehicle repair business added a snow plow to a motor vehicle in such a way that any of the elements of design installed on the vehicle in compliance with a safety standard were 'rendered inoperative,' that entity would have violated the Safety Act. This agency also has authority to investigate allegations that motor vehicles and items of motor vehicle equipment contain defects related to motor vehicle safety, and to order the manufacturer to notify owners and to remedy without charge any vehicles or items of equipment determined to contain a defect related to motor vehicle safety, as provided in sections 151-160 of the Safety Act (15 U.S.C. 1411-1420.) If there were indications that any snow plows contained a defect related to motor vehicle safety, the agency would investigate and take appropriate action. Of course, as with any investigation of alleged safety-related defects, the outcome would depend on the facts of the specific investigation. I hope this information is helpful. If you have any further questions, please feel free to contact Marvin Shaw of my staff at this address or by telephone at (202) 366-2992. Sincerely Paul Jackson Rice Chief Counsel"; |
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ID: aiam2464OpenMr. John J. Giesguth, Director, Bureau of Pupil Transportation, Division of Field Services, Department of Education, P.O. Box 2019, Trenton, New Jersey 08625; Mr. John J. Giesguth Director Bureau of Pupil Transportation Division of Field Services Department of Education P.O. Box 2019 Trenton New Jersey 08625; Dear Mr. Giesguth: This is in reply to your letter of September 9, 1976, requestin information of the legal aspects of the change in the definition of 'school bus.'; Effective April 1, 1977, the definition of 'school bus' in Title 49 o the Code of Federal Regulation (49 CFR S571.3) will read as follows:; >>>'School bus' means a bus that is sold or introduced in interstat commerce, for purposes that include carrying students to and from school or related events, but does not include a bus designed and sold for operating as a common carrier in urban transportation.<<<; The definition of 'bus' will continue to read a follows: >>>'Bus' means a motor vehicle with motive power, except a trailer designed for carrying more than 10 persons.<<<; The new definition of school bus will include many of the van-typ vehicles that are classified as Type II school vehicles under Highway Safety Program Standard No. 17. If a Type II van is designed to carry more than 10 persons, and if it is sold for purposes that include 'carrying students to and from school or related events,' it will have to be sold with all the equipment specified for school buses by the Federal Motor Vehicle Safety Standards. It will therefore have to have school bus lights as specified by the standard on lighting (49 CFR S571.108).; Our experience with the comparative accident patterns of Type I an Type II buses does not justify the use of different lighting systems for the two types. In view of Congress's expressed desire to have the school bus standards uniformly applicable to busses of all sizes, we consider it appropriate to apply the lighting standard to all school buses.; We understand your concern with the effects that the newly applicabl requirements will have on your purchase of Type II vans. However, we are persuaded that the requirements are reasonable and that they will protect school children.; If we can be of further assistance, please let us know. Sincerely, John W. Snow, Administrator |
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ID: aiam0459OpenMr. Robin A. C. Dandy, Senior Engineer, Head of Mechanical Section, British Standards Institution, Hemel Hempstead Centre, Marylands Avenue, Hemel Hempstead, Herts, England; Mr. Robin A. C. Dandy Senior Engineer Head of Mechanical Section British Standards Institution Hemel Hempstead Centre Marylands Avenue Hemel Hempstead Herts England; Dear Mr. Dandy: Your letter of 4 October 1971 encloses drawings of several seat bel buckle installations that show the locations at which you propose to apply the buckle crush forces specified in Standard No. 209. As to each of the buckles depicted, we consider the force lines to be correctly drawn for purposes of the buckle crush test.; Please advise us if we can be of further assistance. Sincerely, Lawrence R. Schneider, 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.