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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| search results table | |
ID: aiam3807OpenMr. Robert Sprafka, EF Technology, 1405 North U.S. 27, St. Johns, MI 48879-0189; Mr. Robert Sprafka EF Technology 1405 North U.S. 27 St. Johns MI 48879-0189; Dear Mr. Sprafka: This is to follow-up on your phone conversation with Stephen Oesch o my staff concerning the application of Standard No. 301, *Fuel System Integrity*, to a school bus that has a natural gas fuel system as original equipment. As discussed below, Standard No. 301 does not apply to a natural gas fuel system.; Standard No. 301 sets fuel system integrity requirements for certai vehicle types, including school buses with a gross vehicle weight rating of 10,000 pounds or more. The standard, however, only applies to those vehicles which use fuel with a boiling point above 32 degrees Fahrenheit. Since natural gas does not have a boiling point above 32 degrees Fahrenheit, the standard would not apply.; Although there are no safety standards applicable to natural gas fue systems, manufacturers are responsible for any safety-related defects in their motor vehicles or items of motor vehicle equipment. Section 151, *et seq*. of the National Traffic and Motor Vehicle Safety Act, a copy of which is enclosed, provide that manufacturers of motor vehicles and motor vehicle equipment must notify owners of vehicles and equipment with safety-related defects and remedy those defects free of charge.; I am also enclosing, for your information, an agency letter discussin the legal responsibilities of persons who converted gasoline fuel systems to use propane and other gas.; Sincerely, Frank Berndt, Chief Counsel |
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ID: aiam1093OpenMr. Huck Knight, Hyland Manufacturing, Inc. 220 First Street, P.O. Box R, Carlisle, IA 50047; Mr. Huck Knight Hyland Manufacturing Inc. 220 First Street P.O. Box R Carlisle IA 50047; Dear Mr. Knight: This is in response to your letter of March 30, 1973, in which yo asked whether the date a vehicle is completed, with reference to the date of manufacture placed on the vehicle certification label, is the date a vehicle comes off the 'main production line' or the date it comes out of the 'final finish production area'.; On this question we are willing, in light of the wide variety o possible factual situations, to let a manufacturer use his own discretion within reasonable limits. As you have described your situation, either date may be used, up to the point where the last physical operations are completed. The 'final quality control checkout', however, would appear to be an operation taking place after the manufacture as we normally understand it is completed.; Yours truly, Richard B. Dyson, Assistant Chief Counsel |
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ID: aiam4291OpenMr. Satoshi Nishibori, Engineering Representative, Nissan Motor Co., Ltd., 560 Sylvan Avenue, Englewood Cliffs, NJ 07632; Mr. Satoshi Nishibori Engineering Representative Nissan Motor Co. Ltd. 560 Sylvan Avenue Englewood Cliffs NJ 07632; Dear Mr. Nishibori: This is in reply to your letter of March 29, 1972, in which you as whether a Certification label 'which is made of some kind of hard material other than paper and affixed on the required place by using only one rivet and by gluing' will meet the requirements of section 567.4(b) of the Certification regulations.; We would consider such a label to be riveted, and consequently to mee the requirements of section 567.4(b).; Sincerely, Richard B. Dyson, Assistant Chief Counsel |
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ID: aiam1569OpenMr. James P. Coughlin, Vice President - Marketing, Bell Helmets Inc., 2850 East 29th Street, Long Beach, CA 90806; Mr. James P. Coughlin Vice President - Marketing Bell Helmets Inc. 2850 East 29th Street Long Beach CA 90806; Dear Mr. Coughlin: This is in reply to your letter of July 25, 1974, asking whether th statement 'Make no modifications' included in the labeling requirements of Standard 218, *Motorcycle Helmets*, would prohibit the after-market installation of a quick release device which may be attached to a helmet's retention strap. You included an illustration of such a device in your letter.; The answer is no. The statement does not restrict after-marke modifications by a first purchaser for purposes other than resale. It only serves to warn the consumer of the danger of making such modifications.; Yours truly, Richard B. Dyson, Acting Chief Counsel |
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ID: aiam3554OpenMr. Vernon J. Clark, Transportation Supervisor, Nebraska Department of Education, 301 Centennial Mall South, Box 94987, Lincoln, NE 68509; Mr. Vernon J. Clark Transportation Supervisor Nebraska Department of Education 301 Centennial Mall South Box 94987 Lincoln NE 68509; Dear Mr. Clark: This responds to your March 23, 1982, letter asking whether it i permissible to install side-facing seats in school buses designed to transport the handicapped. The answer to your question is yes.; Standard No. 222, *School Bus Passenger Seating and Crash Protection* specifies the requirements for school bus passenger seats and, in general, requires those seats to be forward facing. However, the definition of 'school bus passenger seat' in section S4 of the standard excludes seats installed to accommodate handicapped or convalescent passengers as evidenced by installing those seats longitudinally. Therefore, seats installed in the buses to which you refer in your letter need not comply with the school bus seat requirements if they are designed to accommodate the handicapped and are side facing.; We caution, however, that side-facing seats afford less protection tha forward facing seats. Accordingly, only those seats necessary to accommodate the handicapped should be altered in this manner.; Sincerely, Frank Berndt, Chief Counsel |
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ID: aiam1139OpenMr. Thomas S. Pieratt, Jr., Executive Secretary, Truck Equipment & Body Distributors Association, 602 Main Street, Cincinnati, OH 45222; Mr. Thomas S. Pieratt Jr. Executive Secretary Truck Equipment & Body Distributors Association 602 Main Street Cincinnati OH 45222; Dear Mr. Pieratt: In your letter of May 14, 1973, you present the fact situation of a equipment manufacturer who installs lighting equipment on a component which he supplies to distributors or dealers, for installation by them on motor vehicles. For purposes of this letter, I assume that the installation occurs before the first sale of the vehicles for purposes other than resale. You ask what the equipment manufacturer should do to advise the distributor or dealer 'that the lamps and/or reflectors which he has affixed to his product meets the published S.A.E. specs required by Standard 108.'; There is no Federal requirement that an equipment manufacturer in thi fact situation supply compliance information, although covered equipment that he sells must continue to conform. The requirements for certifying or otherwise providing information concerning conformity with Standard No. 108 apply to the manufacturer of the lighting equipment, and the manufacturer(s) (final-stage and others) of the vehicle in question. It may well be that the customers of the supplier you describe will demand assurances of conformity through commercial channels.; Yours truly, Richard B. Dyson, Assistant Chief Counsel |
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ID: aiam3104OpenMr. Phillip L. Whitehorn, Messrs. Cannady & Whitehorn, 2150 Franklin Street, Suite 571, Oakland, California 94612; Mr. Phillip L. Whitehorn Messrs. Cannady & Whitehorn 2150 Franklin Street Suite 571 Oakland California 94612; Dear Mr. Whitehorn: This is in reply to your letter of August 31, 1979, following you discussion with Mr. Vinson of this office.; Your client, ZEMCO Inc., has developed a fuel saving device for th automobile aftermarket the operation of which you have described as follows:; >>>'...if a vehicle approached a read light requiring the driver t stop ... several seconds after the accelerator was released and the automobile stopped the device would automatically shut off the engine. To restart, the driver would press the accelerator pedal and the device would automatically trigger the ignition to start the engine.'<<<; "In your opinion two Federal Motor Vehicle Safety Standards appear t conflict with the ZEMCO device, Standards Nos. 102 and 124. Paragraph S3.1.3 of 49 CFR 571.102, Motor Vehicle Safety Standard No. 102 imposes a starter interlock requirements under which 'the engine starter shall be inoperative when the transmission shift lever is in a forward or reverse drive position.' You point out that ZEMCO's device 'has been designed to automatically restart the engine with the transmission in either forward or reverse.' Paragraph S5.1 of 49 CFR 571.124, Motor Vehicle Safety Standard No. 124 requires the throttle to return to the idle position within a specified time j period 'whenever the driver removes the opposing actuating force.' The ZEMCO device shuts off the engine several seconds after the(sic) driver's foot is removed from the accelerator."; You have cited Section 108(a)(1)(A) of the National Traffic and Moto Vehicle Safety Act which prohibits the manufacture of any item of motor vehicle equipment that does not conform to Federal motor vehicle safety standards, and Section 108(a)(1)(A) which forbids manufacturers, distributors, dealers and motor vehicle repair businesses from 'knowingly rendering inoperative ... any device or element of design installed on or in a motor vehicle ... in compliance with an applicable Federal motor vehicle safety standard.; You have asked whether the ZEMCO device is in conflict with the Act. The ZEMCO device does not violate Section 108(a)(1)(A) of the Act Although it is an item of 'motor vehicle equipment' as defined by Section 102(a) of the Act, there is no Federal motor vehicle safety standard applicable to a device of this nature, so that its manufacture and sale would not be a violation of Section 108(a)(1)(A).; With respect to Section 108(a)(2)(A) we do not see that the devic conflicts with Standard No. 124 as long as the device does not prevent the accelerator from returning to idle in the standard's specified time period before the engine is shut off. The ZEMCO device appears to come into play after the accelerator has returned to idle, a period of time outside the coverage of the standard.; You are correct, however, in your concern with Standard No. 102 as th activation of the starter in forward or reverse gear is diametrically opposed to the standard's requirement. Its installation would appear to 'render inoperative' the starter interlock that is required by Standard No. 102. Although ZEMCO's manufacture of the device would not violate Section 108(a)(2)(A), its installation by a person other than the vehicle owner would appear to.; You are also correct that this agency has not issued the regulatio authorized by Section 108(a)(2)(B) under which any person may be exempted from Section 108(a)(2)(A) upon a determination that the exemption is consistent with motor vehicle safety and the purposes of the Act.; If you wish to petition the agency to issue such a regulation or t amend Standard No. 102 in an appropriate manner you have, of course, the right to do so, and I enclose a copy of our petition procedures, 49 CFR Part 552, for your information.; I return your patent materials herewith. Sincerely, Frank Berndt, Chief Counsel |
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ID: aiam4911OpenMr. Kenneth M. Bush Regulations Manager, Government Relations American Suzuki Motor Corporation 3251 E. Imperial Hwy. P.O. Box 1100 Brea, CA 92622-1100; Mr. Kenneth M. Bush Regulations Manager Government Relations American Suzuki Motor Corporation 3251 E. Imperial Hwy. P.O. Box 1100 Brea CA 92622-1100; "Dear Mr. Bush: This responds to your letter of September 6, 1991, t Mr. Vinson, asking whether a vehicle you are developing would be classified as a multipurpose passenger vehicle for the purposes of the Federal motor vehicle safety standards. I am pleased to be able to explain our law and regulations for you. At the outset, I would like to make clear that the National Traffic and Motor Vehicle Safety Act (15 U.S.C. 1381 et seq.) places the responsibility for classifying a particular vehicle in the first instance on the vehicle's manufacturer. For this reason, NHTSA does not approve or endorse any vehicle classification before the manufacturer itself has classified a particular vehicle. NHTSA may reexamine the manufacturer's classification during the course of any enforcement actions. We will, however, tentatively state how we believe we would classify this vehicle for the purposes of our safety standards. It is important that you understand that these tentative statements of classification are based entirely on our understanding of the information presented in your letter to us. These tentative statements about the vehicle's classification may change after NHTSA has had an opportunity to examine the vehicle itself or otherwise acquire additional information about the vehicle. With those caveats, we believe that the vehicle referenced in your letter could be classified as a multipurpose passenger vehicle for the purposes of our safety standards. The term 'multipurpose passenger vehicle' is defined in 49 CFR 571.3 as 'a motor vehicle with motive power, except a trailer, designed to carry 10 persons or less which is constructed either on a truck chassis or with special features for occasional off-road operation.' In your letter, you state that the vehicle's chassis should be considered a truck chassis because it 'was originally designed to provide cargo-carrying capability as well as to permit rough road and off the road vehicle operation.' Additionally, you state that the approach and departure angles and the running clearance dimensions for this vehicle are more similar to other vehicles which have been classified by their manufacturers as multipurpose passenger vehicles than vehicles that have been classified as passenger cars. Based upon this description, it appears to us that this vehicle could be classified as a multipurpose passenger vehicle. I hope you find this information helpful. The version of your letter that has been placed in the public docket has all the information for which you requested confidential treatment deleted from it. If you have further questions, please contact Mary Versailles of my staff at this address or by telephone at (202) 366-2992. Sincerely, Paul Jackson Rice Chief Counsel"; |
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ID: aiam5603OpenPaul Jackson Rice, Esquire Arent Fox 1050 Connecticut Avenue, NW Washington, DC 20036-5339; Paul Jackson Rice Esquire Arent Fox 1050 Connecticut Avenue NW Washington DC 20036-5339; Dear Mr. Rice: This responds to your letter of August 30, 1995 concerning a June 6, 1995 letter from this office to C. Rufus Pennington, III. You asked us to confirm that the agency did not take a position as to whether there are 'designated seating positions' in the rear of the 1979 911 SC Porsche. You are correct. As the letter clearly states, 'NHTSA cannot make a determination as to whether a vehicle complied with applicable safety standards outside a compliance proceeding.' I hope this information has been helpful. Sincerely, John Womack Acting Chief Counsel; |
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ID: aiam0401OpenMr. 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: Thank you for your letter of May 20, 1971, to Administrator Douglas W Toms, requesting an interpretation of paragraph S5.2(h) of Federal Motor Vehicle Safety Standard No. 209, and particularly of the sentence containing the phrase ...the retractor and webbing shall be suspended vertically...'; Of the two interpretations you submitted, your interpretation 2 i correct. The retractor-webbing combination is suspended vertically--there is no restriction on the attitude of the retractor with respect to the webbing. Thus, the retractor may be suspended in the position it will be mounted in the vehicle relative to the webbing when the webbing is in use.; Please let us know if we can be of further assistance. Sincerely, Lawrence R. Schneider, Acting 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.