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: aiam1869OpenMr. David A. Tenquist, Marketing Department, Novus, Inc., 5301 B Edina Industrial Blvd., Minneapolis, MN 55435; Mr. David A. Tenquist Marketing Department Novus Inc. 5301 B Edina Industrial Blvd. Minneapolis MN 55435; Dear Mr. Tenquist: This is in reply to your letter of March 12, 1975, inquiring as t whether any safety regulation of the National Highway Traffic Safety Administration applies to the Novus Windshield Repair Kit,' manufactured by your firm.; An advertising brochure for the product states that the material use in the process is a special waterproof epoxy that not only fills the fissure in the glass but also bonds the crack surfaces to prevent formation or extension of radial cracks.'; There is no safety regulation of the National Highway Traffic Safet Administration, nor any other Federal law or regulation, which prohibits the use of such a material or process in the repair of windshields which have previously been installed in vehicles and damaged in use. Using such a material or process in a new windshield which may require repair as the result of damage sustained in shipment could cause the windshield to fail to meet the performance requirement of Motor Vehicle Safety Standard No. 205 (49 CFR S 571.205) and we would therefore discourage use of the Novus kit on new windshields.; Please do not hesitate to contact us if we may be of furthe assistance.; Yours truly. Richard B. Dyson, Assistant Chief Counsel |
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ID: aiam3854OpenMr. J. Kawano, General Manager, U.S. Office, Toyota Motor Corporation, One Harmon Plaza, Secaucus, NJ 07094; Mr. J. Kawano General Manager U.S. Office Toyota Motor Corporation One Harmon Plaza Secaucus NJ 07094; Dear Mr. Kawano: This letter replies to your request for an interpretation of FMVSS No 202, *Head Restraints*. Your first question concerns the measurement of the lateral width of a head restraint with a 'Volvo-type configuration.' The drawing attached to your letter appears to depict an adjustable head restraint with a rectangular shape and a hollow center. Paragraph S4(b) of Standard No. 202 requires measurements, according to S4(b)(1) and (2), to be made when the head restraint is 'adjusted to its fully extended design position.' The lateral width of the head restraint of an individual or bucket seat may be measured either 2.5 inches below the top of the restraint or 25 inches above the seating reference point. These are the only two locations at which this measurement may be made. The lateral width may not be measured at part B on your drawing, because B is not the correct location at which to make this measurement. A copy of this drawing is enclosed for your convenience.; Your letter and drawing indicate a concern that, if the lateral widt is measured 2.5 inches below the top of the restraint, the hollow space between the two sides of the rectangular head restraint may not be included in measuring the total width. Using the information you have supplied, we believe that the lateral width of this type of head restraint, measured either 2.5 inches below the top of the restaint or 25 inches above the seating reference point, would include the hollow space, if the hollow space occurs at either location. The lateral width would also include, of course, the widths of both sides of this restraint, marked A1 and A2 in your drawing. This lateral width may or may not equal the width, B, located at the top of the restraint in your drawing.; Your second question regarding the correct demonstration procedure t test compliance with Standard No. 202 is answered by the language of paragraph S5.2 of the standard. This paragraph states that, if the head restraint conforms to S4(b), compliance is demonstrated in accordance with S5.2 with the head restraint in its fully extended design position. The dynamic testing procedure would not be required, unless your head restraint conforms to paragraph S4(a). The manufacturer has the option of designing a head restraint which meets the performance requirements of either paragraph S4(a) or paragraph S4(b).; Sincerely, Frank Berndt, Chief Counsel |
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ID: aiam2746OpenMr. James Tydings, Thomas Built Buses, 1408 Courtesy Road, P.O. Box 2450, High Point, NC 27261; Mr. James Tydings Thomas Built Buses 1408 Courtesy Road P.O. Box 2450 High Point NC 27261; Dear Mr. Tydings: This responds to your December 8, 1977, letter asking for a interpretation of the term 'passenger compartment' as used by the National Highway Traffic Safety Administration (NHTSA) in Standard No. 217, *Bus Window Retention and Release*.; Standard No. 217 requires that a school bus side emergency door b located in the rear half of the bus passenger compartment. The NHTSA interprets the term 'passenger compartment' to mean the area from the windshield to the back of the bus.; In a companion question, you ask whether it would be permissible for small portion of a side emergency door, installed pursuant to S5.2.3.1(b), to fall within the front half of a bus as long as most of the door is within the required rear half of the passenger compartment. The answer to your question is no. The emergency door must be totally located within the rear half of the passenger compartment.; Sincerely, Joseph J. Levin, Jr., Chief Counsel |
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ID: aiam5083OpenDonald G. McGuigan, Esq. Ford Motor Company Office of the General Counsel Suite 728 - Parklane Towers East One Parklane Boulevard Dearborn, MI 48126-2493; Donald G. McGuigan Esq. Ford Motor Company Office of the General Counsel Suite 728 - Parklane Towers East One Parklane Boulevard Dearborn MI 48126-2493; "Dear Mr. McGuigan: This responds to your letter of September 29, 199 concerning certain new requirements of Federal Motor Vehicle Safety Standard No. 114, Theft Protection, which became effective on September 1, 1992. Your questions relate to S4.2.1 of the standard, which states: S4.2.1 Except as provided in S4.2.2(a) and (b), the key-locking system required by S4.2 in each vehicle which has an automatic transmission with a 'park' position shall prevent removal of the key unless the transmission or transmission shift lever is locked in 'park' or becomes locked in 'park' as the direct result of removing the key. You argued that this provision should be interpreted to prevent key removal only when the transmission shift lever is in one of the available gear selector positioning detents other than 'park,' i.e., reverse, neutral, drive, first, second, and not when the lever is at various points between those detents. You stated that a compliance test involving positioning of the shift lever between gear positions would be 'inappropriate,' because you believe that it would be premised on an assumption that a substantive purpose of the amendment is to prevent shifting errors. You therefore argue that vehicles in which the key can be removed while the shift lever is between gear positions would not fail to comply with the amended standard. We cannot agree with your suggested interpretation, as it is inconsistent with the express language of S4.2.1. That section states that, with certain exceptions not at issue, the key-locking system must prevent removal of the key unless the transmission or transmission shift lever is locked in 'park' or becomes locked in 'park' as the direct result of removing the key. Stated more simply, key removal must be prevented in all circumstances save those specified in S4.2.1. Neither the transmission nor the transmission shift lever is locked in 'park' when the lever is between the gear selector positioning detents. Therefore, under section S4.2.1, key removal must be prevented in that situation, unless the transmission/ transmission shift lever becomes locked in 'park' as a direct result of removing the key. Our interpretation is consistent with the agency's intent in promulgating S4.2.1. As discussed in several rulemaking notices, NHTSA amended Standard No. 114 to prevent vehicle rollaway caused by unattended children shifting the transmission lever in automatic transmission vehicles. If a driver were able to remove the key while the transmission or transmission shift lever was not locked in park, and if the transmission or transmission shift lever did not become locked in 'park' as a result of removing the key, a child might later shift the transmission lever, thereby causing a vehicle rollaway. For this reason, we continue to believe that this amendment to Standard No. 114 meets the need for motor vehicle safety. I note that while it may be true that NHTSA would not commence a rulemaking proceeding focused solely on preventing inadvertent vehicle movement arising out of transmission shift lever mispositioning, as reflected in the agency's June 1990 denial of the Barr petition, this does not mean that Standard No. 114, as construed above, does not achieve a valid and appropriate safety benefit. You asked about Standard No. 114 in connection with the key-locking systems of 1993 Escorts and Tracers. You stated that if attempts are made to remove the ignition key with the transmission shift lever in each of the available gear selector positioning detents, the key-locking systems of these vehicles prevent removal of the key except when the transmission shift lever is locked in the 'park' detent. You also stated, however, that if attempts are made to remove the ignition key with the transmission shift lever at various points between reverse and park, the key can be removed, for at least a large proportion of these vehicles, at certain points where the selector lever is 'held short of engaging the Park positioning detent.' We recognize that you believe that the chances of a vehicle rollaway occurring with your system would be very small. While you have made a number of arguments to support your contention, we note that we cannot consider that type of argument in interpreting Standard No. 114. As you know, under the National Traffic and Motor Vehicle Safety Act, NHTSA is required to issue safety standards that provide objective criteria. In interpreting a standard, we must follow those objective requirements, notwithstanding arguments regarding the safety significance of a particular vehicle design. If you believe that those arguments have merit, you may present them to the agency in other contexts, such as in a petition for determination of inconsequential noncompliance. I hope this information is helpful. Sincerely, Paul Jackson Rice Chief Counsel"; |
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ID: aiam5129OpenMr. Nilton Mello Vitrotec - Vidros De Seguranca Ltda Rua Jacofer, 350 CEP 02712 Sao Paulo, Brazil; Mr. Nilton Mello Vitrotec - Vidros De Seguranca Ltda Rua Jacofer 350 CEP 02712 Sao Paulo Brazil; "Dear Mr. Mello: This responds to your inquiry about the exportation o your laminated motor vehicle windshields into the United States. According to your letter, you have already designated an agent in this country and have received your DOT number. You asked whether you are required to perform tests at an American laboratory before you can export your product into the United States. I am pleased to have this opportunity to respond to your inquiry. I am also enclosing a copy of a fact sheet entitled 'Information for New Manufacturers of Motor Vehicles and Motor Vehicle Equipment.' By way of background information, section 103 of the National Traffic and Motor Vehicle Safety Act ('Safety Act,' 15 U.S.C. 1392) authorizes NHTSA to issue safety standards for new motor vehicles and new items of motor vehicle equipment. NHTSA does not however approve or certify any vehicles or items of equipment. Instead, the Safety Act establishes a 'self-certification' process under which each manufacturer is responsible for certifying that its products meet all applicable safety standards. NHTSA tests vehicles and equipment sold to consumers for compliance with safety standards and investigates defects relating to motor vehicle safety. If a manufacturer or NHTSA determines that a noncompliance or safety-related defect exists, the manufacturer must notify purchasers of its product and remedy the problem free of charge. A manufacturer of noncomplying or defective products is also subject to civil penalties. In response to your question about whether you are required to perform tests at an American laboratory, the answer is no. As indicated above, manufacturers of motor vehicles and motor vehicle equipment are required to certify that their products comply with all applicable safety standards. Manufacturers must have some basis for their certification. This does not necessarily mean that a manufacturer must conduct the specific tests set forth in an applicable standard. Certifications may be based on, among other things, engineering analyses, actual testing, and computer simulations. You are not required to use the services of an American laboratory in conducting tests associated with certification. I hope that you find this information helpful. If you have any other questions, please contact Marvin Shaw of my staff at this address or by phone at (202) 366-2992. Sincerely, John Womack Acting Chief Counsel Enclosures"; |
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ID: aiam2316OpenGovernor Raymond P. Shafer, Counselor to the Vice President; Governor Raymond P. Shafer Counselor to the Vice President; SUBJECT: Letter to the Vice President from Mr. James A. Graham President, General Industrial Group, Gulf + Western Manufacturing Company; Attached is a suggested draft reply to Mr. James A. Graham's letter o April 30, 1976, to the Vice President concerning a petition for reconsideration of the Part 581 - bumper standard.; James B. Gregory, Administrator Department of Transportation, *Suggested Reply* Dear Mr. Graham: This is in response to your letter of April 30, 1976, concerning Gulf Western's petition for reconsideration of the recently issued Part 581 bumper standard.; It is the policy of the National Highway Traffic Safety Administratio (NHTSA) to 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. Several manufacturers, including Gulf + Western, have filed petitions for reconsideration of the standard in conformance with NHTSA rulemaking procedures (40 CFR 553.35). 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 in your letter.; The NHTSA will give full and thorough consideration to the comments an information submitted by Gulf + Western and the other petitioners. The agency's response to the petitions will be published in the *Federal Register*.; Sincerely, |
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ID: aiam3911OpenMr. M. Iwase, Manager, Technical Administration Dept., Koito Manufacturing Co., Ltd., Shizuoka Works, 500, Kitawaki, Shimizu- shi, Shizuoka-ken, Japan; Mr. M. Iwase Manager Technical Administration Dept. Koito Manufacturing Co. Ltd. Shizuoka Works 500 Kitawaki Shimizu- shi Shizuoka-ken Japan; Dear Mr. Iwase: This is in reply to your letter of February 1, 1985, with reference t the compliance with Motor Vehicle Safety Standard No. 108 of a proposed motorcycle headlamp design.; In the design shown in your letter a single housing would contain tw dual-filament bulbs, each with an independently aimed reflector. You have stated that the headlamp can comply with the photometric requirements of SAE J584 when either compartment is lit, and that the assembly will meet all other requirements of J584.; A dual bulb arrangement in a single housing is considered a singl headlamp, and therefore its compliance will be judged when both compartments are lit to provide either the upper or lower beam. Assuming that when both compartments are lit the combined candlepower at individual test points does not exceed the maxima imposed by J584 for those test points, your design appears to comply with Standard No. 108.; Sincerely, Jeffrey R. Miller, Chief Counsel |
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ID: aiam2603OpenMr. R. G. Wilkins, Product Safety & Reliability Analyst, Grove Manufacturing Company, Shady Grove, PA 17256; Mr. R. G. Wilkins Product Safety & Reliability Analyst Grove Manufacturing Company Shady Grove PA 17256; Dear Mr. Wilkins: This responds to your February 17, 1977, letter concerning Nationa Highway Traffic Safety Administration's (NHTSA) tire label requirements contained in Standard No. 120, *Tire Selection and Rims for Motor Vehicles Other Than Passenger Cars*. You address the situation in which it is not practicable to affix the information label to the door.; Location of vehicle certification labels and tire information labels i governed by Part 567.4(c). This section provides that the primary location of the required labels is either the hinge pillar, door-latch post, or door edge that meets the door-latch post, next to the drivers (sic) seating position, or if none of these locations is practicable, to the left side of the instrument panel. Further, if none of the above locations is practicable, you may request an alternate location from the agency. I am enclosing a copy of Part 567 explaining how to request an alternate location for the information label.; Sincerely, Joseph J. Levin, Jr., Chief Counsel |
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ID: aiam5596OpenMr. Isaias Rios Product Engineering Department Rines de Acero K-H, S.A. de C.V. Hidalgo No. 8 Esquina Plano Regulador Xocoyahualco, Tlalnepantla Estado de Mexico C.P. 54080 Mexico; Mr. Isaias Rios Product Engineering Department Rines de Acero K-H S.A. de C.V. Hidalgo No. 8 Esquina Plano Regulador Xocoyahualco Tlalnepantla Estado de Mexico C.P. 54080 Mexico; "Dear Mr. Rios: This responds to your letter of June 29, 1995, t Marvin Shaw of this office requesting information on obtaining a certification from the U.S. that the wheels you supply to automobile manufacturers in Mexico comply with Federal Motor Vehicle Safety Standard (FMVSS) Nos. 110 and 120. You explained in your letter and in telephone conversations with Walter Myers of this office that your company supplies steel and aluminum passenger car wheels to automobile manufacturers located in Mexico. You stated that Nissan Mexicana requires from you a certificate demonstrating compliance with FMVSS Nos. 110, Tire Selection and Rims, and 120, Tire Selection and Rims for Motor Vehicles Other Than Passenger Cars. Your letter asked how to obtain such a certification and for information on other responsible U.S. government agencies and approved test labs. On July 21, Mr. Myers telefaxed you copies of two interpretative letters previously issued by this office, one to Mr. Ralph Trimarchi dated February 11, 1985, and one to Mr. Jay D. Zeiler dated November 20, 1977. We explained in those letters that U.S. law requires motor vehicle and equipment manufacturers to self-certify their products and that the U.S. government does not test or certify products prior to first retail sale. Rather, this agency, the National Highway Traffic Safety Administration (NHTSA), randomly tests vehicles and equipment for compliance with the FMVSSs. Mr. Myers also telefaxed you copies of FMVSS Nos. 110 and 120 on July 24, 1995. We would like to advise you of another issue. 49 Code of Federal Regulations (CFR) Part 566 (copy enclosed) requires manufacturers of motor vehicle equipment to which an FMVSS applies (referred to in the regulation as 'covered equipment,' such as wheels) to submit its name, address, and a brief description of the items of equipment it manufactures to NHTSA. NHTSA requires that information from an equipment manufacturer even though the equipment manufacturer does not directly sell its products in the U.S. but supplies them to foreign vehicle manufacturers who sell their vehicles in the U.S. (see enclosed copy of NHTSA letter to Mr. K. Nakajima, dated January 6, 1972). Therefore, if your company has not already done so, please submit the information required by Part 566 to the Administrator of NHTSA within thirty days after receipt of this letter. No forms or prescribed format is required. A standard letter is sufficient. I hope this information is helpful to you. Should you have any further questions or need any additional information, please feel free to contact Mr. Myers at this address or by telephone (202) 366-2992 or telefax (202) 366-3820. Sincerely, John Womack Acting Chief Counsel Enclosures"; |
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ID: aiam2253OpenMr. Alvin L. Slayton, Product Reliability Department, American Bosch Electrical Products, P. O. Box 2228, Columbus, MS 39701; Mr. Alvin L. Slayton Product Reliability Department American Bosch Electrical Products P. O. Box 2228 Columbus MS 39701; Dear Mr. Slayton:#This responds to your February 23, 1976, questio whether Standard No. 104, *Windshield Wiping and Washing Systems*, still references SAE J903a as it did in 1969, and whether a future reference to SAE J903b or SAE J903c is anticipated.#The answer to your first question is yes. The answer to your second question is no. A proposed change in Standard No. 104 would be published in the *Federal Register*, and interested persons would be given an opportunity to comment.#Yours truly, Stephen P. Wood, Assistant 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.