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: aiam3658OpenMr. M. Iwase, Manager, Technical Administration Department, Koito Mfg. Co., Shizuoka Works, 500, Kitawaki, Shimizu-Shi, Shizuoka-Ken, Japan; Mr. M. Iwase Manager Technical Administration Department Koito Mfg. Co. Shizuoka Works 500 Kitawaki Shimizu-Shi Shizuoka-Ken Japan; Dear Mr. Iwase: This is in reply to your letter of January 27, 1983, to Mr. Elliott o this agency asking whether your 'lighting device with 1 bulb and 2 functions' is permissible under Federal Motor Vehicle Safety Standard No. 108.; The front combination lamp design (parking lamp and side marker lam functions) is permissible provided that, as you note, all color and photometric requirements for the respective functions are met.; Sincerely, Frank Berndt, Chief Counsel |
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ID: aiam1665OpenMs. Joan M. Markey, Rogers and Wells, 200 Park Avenue, New York, NY 10017; Ms. Joan M. Markey Rogers and Wells 200 Park Avenue New York NY 10017; Dear Ms. Markey: This is in response to the October 22, 1974 letter from Mr. James L Warren inquiring as to the existence of any Federal safety regulations requiring that a warning against welding be affixed to motor vehicle fuel tanks.; This agency has promulgated no regulation requiring manufacturers t affix a label to the fuel tanks of their vehicles warning against welding. A safety standard does exist which establishes performance levels of fuel systems (49 CFR 571.301). However, the standard's requirements focus on the strength and durability of the system and do not include requirements for labeling.; Yours truly, Richard B. Dyson, Acting Chief Counsel |
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ID: aiam0977OpenMr. William M. Hicks, Colson & Hicks, Law Offices, 66 West Flagler Street, Miami, Florida 33130; Mr. William M. Hicks Colson & Hicks Law Offices 66 West Flagler Street Miami Florida 33130; Dear Mr. Hicks: This is in response to your letter of January 25, 1973, which requeste information on Federal Motor Vehicle Safety Standard No. 124, *Accelerator Control Systems*.; This standard was issued by the National Highway Traffic Safet Administration on March 31, 1972. A copy of the standard, including a preamble discussing issues raised in public comments, is enclosed for your review and information.; We appreciate your interest in motor vehicle safety. If we can be o any further service, please let us know.; Sincerely, E.T. Driver, Director, Office of Operating Systems, Moto Vehicle Programs; |
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ID: aiam4467OpenMr. Dana Strahan City of Orange Water Department P. O. Box 449 Orange, CA 92666-1591; Mr. Dana Strahan City of Orange Water Department P. O. Box 449 Orange CA 92666-1591; "Dear Mr. Strahan: This is in response to your inquiry earlier thi year to Mr. Ralph Hitchcock of our Rulemaking Division, in which you asked for information about Federal regulations that apply to the labeling of a vehicle that has been modified to increase its gross vehicle weight rating (GVWR) above that on the original label. I am pleased to have this opportunity to explain our certification regulations to you. Some background information on Federal motor vehicle safety laws and regulations may be helpful. As you are aware, our agency is authorized, under the National Traffic and Motor Vehicle Safety Act (15 U.S.C. 1381 et seq., Safety Act), to issue safety standards applicable to new motor vehicles and certain items of motor vehicle equipment. NHTSA, however does not approve motor vehicles or motor vehicle equipment, nor do we endorse any commercial products. 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. For the purposes of this response, I have assumed that you were concerned about modifying vehicles that are already owned by the City of Orange Water Department. If this is incorrect, and you plan to modify new vehicles before their first sale or your department is in the business of modifying other persons' vehicles, please let me know because different requirements would apply. Neither the Safety Act nor any of our standards and regulations apply to modifications individual vehicle owners make to their own vehicles. Therefore, as a local government agency, the city of Orange, using in-house resources, can perform whatever modifications it desires to its own vehicles. Similarly, our certification regulation does not require modifiers of used vehicles to provide a separate certification label for the modified vehicle. As a word of caution, however, we suggest that any modification made to a vehicle that changes the GVWR assigned by the vehicle's original manufacturer should only be done after the modifier has made a thorough engineering analysis of the entire vehicle. We would suggest that you contact the original vehicle manufacturer for help in making such an analysis. You also indicated that you were concerned about potential liability that could arise if no additional label were affixed to show the modified vehicle's new GVWR. As explained above, a person modifying his or her own vehicle after its first purchase would not be subject to any potential liability under Federal law. If you are asking for information about potential liability under the laws of the State of California, this agency does not comment on such potential liability. I suggest that you contact the Attorney General for the State of California or a local attorney for an opinion about potential liability under California law. I hope this information proves helpful. Please contact this agency again if we can be of further assistance. Sincerely, Erika Z. Jones Chief Counsel"; |
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ID: aiam4172OpenMr. Brian Peck, President, Rearscope International (U.S.A.) Ltd., 15255 Hesperian Boulevard, San Leandro, CA 94578; Mr. Brian Peck President Rearscope International (U.S.A.) Ltd. 15255 Hesperian Boulevard San Leandro CA 94578; Dear Mr. Peck: Thank you for your letter of May 19, 1986, asking how our regulation apply to your product, which is called the 'Rearscope Wide Angle Lens.' Your letter and the brochure you enclosed describes your product as a wide angle acrylic lens which mounts on the rear window of a bus and gives the driver a wider field of view to the rear of the vehicle. I hope the following discussion answers your questions.; By way of background, the National Highway Traffic Safet Administration has the authority to issue safety standards applicable to new motor vehicles and certain items of motor vehicle equipment. NHTSA, however, does not approve motor vehicles or motor vehicle equipment, nor do we endorse any commercial products. Instead the National Traffic and Motor Vehicle Safety Act establishes a 'self-certification' process under which each manufacturer is responsible for certifying that its products meet all applicable safety standards. The agency periodically tests vehicles and equipment items for compliance with the standards, and also investigates other alleged safety-related defects.; We have issued Federal Motor Vehicle Safety Standard No. 205, *Glazin Materials*, which specifies performance and location requirements for glazing used in vehicles. These requirements include specifications for minimum levels of light transmittance (70% in areas requisite for driving visibility, which includes all windows in passenger cars) as well as other performance requirements for glazing.; Standard No. 205 does not directly apply to add-on window coverings such as tinting films, sunscreening devices, and lens. However, no manufacturer or dealer is permitted to install a device on the glazing, such as the viewing lens described in your letter, in *new* vehicles without certifying that the vehicle continues to be in compliance with the light transmittance and other requirements of the standard.; After a vehicle is first sold to a consumer, modifications to a vehicl are affected by section 108(a)(2)(A) of the Vehicle Safety Act. That section prohibits commercial businesses from tampering with safety equipment installed on a vehicle in compliance with our standards. Thus, no dealer, manufacturer, repair business or distributor can install a device for the owner of the vehicle, if the device would cause the window not to meet the requirements of Standard No. 205. Violation of the 'render inoperative' provision can result in Federal civil penalties of up to $1,000 for each violation.; Section 108(a)(2)(A) does not affect vehicle owners, who may themselve alter their vehicles as they please, so long as they adhere to all State requirements. Under Federal law, the owner may install any type of device regardless of whether the installation adversely affects the window. Individual States govern the operational use of vehicles by their owners and therefore it is within the authority of the States to regulate the use of viewing devices in vehicles.; If you need further information, please let me know. Sincerely, Erika Z. Jones, Chief Counsel |
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ID: aiam0998OpenMr. Walter S. McPhail, President, Lectron Products, Inc., 1810 Stephenson Highway, Troy, MI 48084; Mr. Walter S. McPhail President Lectron Products Inc. 1810 Stephenson Highway Troy MI 48084; Dear Mr. McPhail: This is in reply to your letter of January 29, 1973, concerning you safety belt interlock system.; Paragraph S7.4.1 of Federal Motor Vehicle Safety Standard No. 208 Occupant Crash Protection, requires that the belt system at each occupied seating position be operated after the occupant is seated in order to start the engine. It is our opinion that a system such as yours, which senses whether the safety belt is properly buckled around the occupant before allowing the engine to start would meet the above requirements and could be used under the option described in S4.1.2.3.; Yours truly, Richard B. Dyson, Assistant Chief Counsel |
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ID: aiam1370OpenMr. M. L. Higgins, Truck Trailer Manufacturers Association, 2430 Pennsylvania Avenue, N.W., Washington, DC 20037; Mr. M. L. Higgins Truck Trailer Manufacturers Association 2430 Pennsylvania Avenue N.W. Washington DC 20037; Dear Mr. Higgins: This is in reply to your letter of November 26, 1973, asking whethe motor vehicle new or used car dealers are prohibited from selling vehicles mounted on regrooved or recapped tires. You indicated in a phone conversation with Michael Peskoe of this office that your concern is with motor vehicles generally, and not passenger cars alone.; New passenger cars are required to be sold with tires meeting th requirements of Motor Vehicle Safety Standard No. 109 (49 CFR 571.110). New vehicles other than passenger cars are not presently required by NHTSA regulations to be sold with particular tires, but requirements in this regard have been proposed (36 F.R. 14273, August 3, 1971).; This agency has no requirements regarding the sale of used moto vehicles equipped with recapped or retreaded tires. However, buses subject to Bureau of Motor Carrier Safety regulations are prohibited from operating with recapped, retreaded, or regrooved tires on their front wheels (49 CFR S 393.75(d)).; Trucks and truck tractors subject to Motor Carrier Safety requirement may not be operated with regrooved tires on the front wheels which have a load carrying capacity equal to or greater than that of 8.25-20 8 ply-rating tires (49 CFR 393.75(e)). For more inforamtion regarding the applicability of these requirements you should contact, Regualtions Division Bureau of Motor carrier Safety, Federal Highway Administration, United States Department of Transportation, Washington, DC 20590.; The sale of regrooved tires is subject to regulations issued by thi agency (49 CFR Part 569). the recent opinion issued by the United States Court of Appeals (*NAMBO* v. *Brinegar*, D.C. Dir., Case No. 71-1268, July 26, 1973) appears to allow the sale of regrooved tires under these regulations in certain circumstances. We believe the opinion is unclear in this regard, and as a result we have determined to seek additional judicial review to further clarify the matter.; Yours truly, Richard B. Dyson, Assistant Chief Counsel |
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ID: aiam3382OpenMr. T. Shimada, Senior Technical Manager, MMC Services Inc., 3000 Town Center, Suite 1960, Southfield, MI 48075; Mr. T. Shimada Senior Technical Manager MMC Services Inc. 3000 Town Center Suite 1960 Southfield MI 48075; Dear Mr. Shimada: This responds to your letter of October 14, 1980, regarding the warnin devices required by Safety Standard No. 114, *Theft Protection*, and Safety Standard No. 208, Occupant Crash Protection. You ask whether the sound of a voice repeating the phrase 'please pull out the ignition key' or 'please fasten seat belt' at 2-3 second intervals could be used to satisfy the requirements of Standard No. 114 and Standard No. 208. You also ask whether a buzzer or chime that signals an unfastened seat belt or the presence of the key in the ignition could also be used to give the driver other warnings, such as turning off the headlights.; Standard No. 114 does not specify the nature of the warning that mus be given to the driver in the event that the ignition key is left in the locking system. Thus the system you describe would comply with the rule. Notre that the signal must be activated whenever the key has been left in the ignition and the driver's door is opened.; Standard No. 208 requires that the driver's seating position b equipped with a warning system that activated a continuous or intermittent audible signal for a period of not less than four (4) seconds and not more than eight (8) seconds. The signal must begin when the vehicle's ignition switch is in the 'on' or 'start' position and the driver's belt is not in use. If the system you have devised stops the warning only when the belt has been fastened, it would not comply with this rule. The signal must end within eight (8) seconds, irregardless(sic) of whether the driver's belt has been fastened. Regardless your specific question, an audible 'voice' signal would be permitted under the standard.; The buzzers or chimes that are installed in accordance with Standar No. 214 or Standard No. 208 may also be used to warn the driver of other conditions.; We hope you find this information helpful. Please contact this offic if you have any other questions.; Sincerely, Frank Berndt, Chief Counsel |
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ID: aiam4650OpenMr. David G. Gould Legislation Department Lotus Engineering Hethel, Norwich, Norfolk NR14 8EZ ENGLAND; Mr. David G. Gould Legislation Department Lotus Engineering Hethel Norwich Norfolk NR14 8EZ ENGLAND; "Dear Mr. Gould: Thank you for your letter asking whether a worl manufacturer identifier (WMI) assigned by the Society of Automotive Engineers (SAE) pursuant to a contract with this agency may be deleted from SAE's register of assigned WMIs upon request of a foreign national governmental agency, but without the consent of the holder of the WMI. Absent some extraordinary circumstances, the answer to your question is no. 49 CFR Part 565, Vehicle Identification Number - Content Requirements, sets forth format and content requirements for vehicle identification numbers (VINs). Section 565.4(a) specifies that the first three characters of the VIN shall be the manufacturer's WMI, which is 'assigned in accordance with /565.5(c) of this part.' Section 565.5(c) specifies that the SAE assigns WMIs to vehicle manufacturers under contract with the National Highway Traffic Safety Administration (NHTSA). No provision in NHTSA's regulations sets forth any procedures for deleting assigned WMIs from the SAE register upon the request of any party, even the manufacturer assigned the WMI. Similarly, no provision in the contract specifically addresses the issue of deleting assigned WMIs for any reason. In its contract with NHTSA, SAE has agreed to 'furnish the facilities, materials, personnel and services necessary to accomplish the work...' We contacted the SAE's WMI Coordinator to learn how they have handled this situation in the past. We were informed that the WMIs are assigned by the SAE for an indefinite period with no express provision for revocation of the assignment. There have been a few isolated instances in which the party to whom a WMI was assigned has contacted SAE and asked that the WMI assignment be revoked. In those instances, the SAE has granted the manufacturer's request but the revoked WMI is never reassigned to another manufacturer. To date, SAE has never been asked to delete an assigned WMI by any party other than the manufacturer to whom the WMI was assigned. If a situation arose in which the SAE was asked to delete an assigned WMI without the knowledge and consent of the manufacturer to whom the WMI was assigned, the SAE assures us that they would not act on the request without consulting this agency. If and when we are ever consulted by SAE for our opinion on how to handle such a request, we would carefully consider the circumstances of the particular case before advising SAE on how to respond to the request. As a general matter, however, NHTSA does not favor the deletion of assigned WMIs for any reason. Sincerely, Stephen P. Wood Acting Chief Counsel"; |
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ID: aiam3195OpenMr. Brian Gill, Manager, Certification Department, American Honda Motor Co., Inc., P.O. Box 50, 100 W. Alondra Boulevard, Gardena, California 90247; Mr. Brian Gill Manager Certification Department American Honda Motor Co. Inc. P.O. Box 50 100 W. Alondra Boulevard Gardena California 90247; Dear Mr. Gill: This is in response to your letter of November 18, 1979, requesting a interpretation as to whether the VIN plate samples you enclosed with your letter comply with the requirements of Standard No. 115, *Vehicle identification number*.; You enclosed two proposed VIN plates in your letter, one fo automobiles and one for motorcycles.The VIN plates themselves and the pre-printed lettering which appears on them seem to conform to the requirement of Standard No. 115. The lettering is clear and indelible, as required by S4.3, in that it cannot be removed without damage to the surface on which it is printed. Further, the plate when riveted to the vehicle would be considered to be permanently affixed in that it cannot be removed without damage (S4.3). The type face utilized for the lettering consists of capital, sans serif characters with a minimum height of 4 mm as required by S4.3.1.; The letters stamped on the automobile VIN plate 'SL5322AS000001', ca hardly be seen, and would not appear to meet the requirements of S4.3 and S4.4.; Sincerely, Frank Berndt, 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.