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: aiam3771OpenThe Honorable Robert A. Young, Member of Congress, 4150 Cypress Road, St. Ann, MO 63074; The Honorable Robert A. Young Member of Congress 4150 Cypress Road St. Ann MO 63074; Dear Mr. Young: Thank you for your letter of October 13, 1983, concerning the potentia hazards posed to law enforcement officials by the use of opaque glass in automobiles. Through the exercise of its motor vehicle safety authority, the agency has addressed a part of this potential problem. However, given the limitations on the agency's authority, additional State action is needed to eliminate this potential problem.; Pursuant to the National Traffic and Motor Vehicle Safety Act, th agency has issued Federal Motor Vehicle Safety Standard No. 205, *Glazing Materials*, which specifies performance and location requirements for glazing used in vehicles. These requirements include specifications for minimum levels of light transmittance (70 percent in areas requisite for driving visibility, which includes all windows in passenger cars) and abrasion resistances. The specification for light transmittance precludes darkly-tinted windows in new automobiles.; In past interpretation letters, the agency has said that solar film an other materials used to make windows opaque are not glazing materials themselves and would not have to comply with Standard No. 205. However, installation of such films on new motor vehicles would be prohibited if the vehicle glazing no longer complied with the light transmittance of abrasion resistance requirements of the standard. If a manufacturer or a dealer places the film on glazing in a vehicle prior to the first sale of the vehicle, that manufacturer or dealer has to certify that the glazing continues to be in compliance with the requirements of Standard No. 205.; After a new vehicle has been sold to the consumer, he may alter th vehicle as he pleases, so long as he adheres to all State requirements. Under Federal law, the owner could install the tinting or other film on glazing in his vehicle whether or not the installation adversely affected the light transmittance and abrasion resistance of the glazing. Section 108(a)(2)(A) of the Vehicle Safety Act provides that no manufacturer, distributor, dealer or motor vehicle repair business shall knowingly render inoperative any device or element of design installed on or in a motor vehicle in compliance with an applicable motor vehicle safety standard. 'Render inoperative' means to remove, disconnect or degrade the performance of a system or element of design installed to comply with a Federal safety standard. Thus, none of those persons may knowingly install a tinting or other film on a vehicle for an owner if that action would render inoperative the light transmittance or abrasion resistance performance of the vehicle's glazing. Violation of the render inoperative provision can result in Federal civil penalties of up to $1,000 for each violation.; State law, rather than Federal law, governs the operational use o vehicles by their owners. Thus, it is up to the States to preclude owners from applying tinting or other films to their vehicle windows. A number of States have already adopted such laws. The agency would be glad to provide technical assistance on glazing requirements to the appropriate Missouri highway safety officials working on this problem.; I hope this explains the agency's authority to address the potentia problems posed by tinting and other films. If you need further information, the agency will be glad to provide it.; Sincerely, Diane K. Steed |
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ID: aiam3321OpenMr. Terry Coleman, Codes and Safety Manager, Airstream, Jackson Center, OH 45334; Mr. Terry Coleman Codes and Safety Manager Airstream Jackson Center OH 45334; Dear Mr. Coleman: This responds to your June 13, 1980, letter asking whether your compan would be considered a chassis-cab manufacturer subject to the labeling requirements of Part 567, *Certification*. You indicate that you take another manufacturer's incomplete chassis with a motor and add to it a cab and body with bumpers, mirrors, and exterior trim. This vehicle is then sent to a final-stage manufacturer for final completion. We would not consider you to be a chassis-cab manufacturer subject to the certification requirements.; As you know, a chassis-cab is defined in Part 567 as 'an incomplet vehicle, with a completed occupant compartment, that requires only the addition of cargo carrying, work performing, or load bearing components to perform its intended functions.' The incomplete vehicle upon which your manufacturing operation begins is simply a chassis without the cab. As such, that vehicle is subject to the incomplete vehicle document requirements of Part 568, but it is not subject to the chassis-cab certification requirements.; Your modification adds on a bus body which then needs final work befor it can be used. Since you do not complete the occupant compartment as required by the definition of 'chassis-cab', you are not required to attach a certification label. You are simply an intermediate manufacturer. The final- stage manufacturer would attach the only label to the vehicle.; Sincerely, Frank Berndt, Chief Counsel |
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ID: aiam2926OpenMr. Paul G. Scully, Chairman, SAE Lighting Committee, State Road 7, P.O. Box 766, Madison, IN 47250; Mr. Paul G. Scully Chairman SAE Lighting Committee State Road 7 P.O. Box 766 Madison IN 47250; Dear Mr. Scully: This is in reply to your letter of December 18, 1978, asking for a interpretation of Federal Motor Vehicle Safety Standard No. 108.; The standard was recently amended to establish a ceiling of 60 inche from the roadway surface for the mounting height of rear side marker lamps. You have asked whether it is permissible to mount an additional side marker lamp at the upper rear corner of a trailer whose overall height exceeds 60 inches.; The answer is yes. Such a supplemental lamp would not appear to impai the effectiveness of lighting equipment required by Standard No. 108, within the meaning of the prohibition of S4.1.3 that you mentioned.; Sincerely, Joseph J. Levin, Jr., Chief Counsel |
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ID: aiam3634OpenMr. A. J. Burgess, Vice President (Technical), Lucas Industries Inc., 5500 New King Street, Troy, MI 48098; Mr. A. J. Burgess Vice President (Technical) Lucas Industries Inc. 5500 New King Street Troy MI 48098; Dear Mr. Burgess: This is in reply to your letter of November 1, 1982, regarding a interpretation of the 'lens area requirements of FMVSS No. 108' as applied to the high contrast lamp whose design you enclosed.; We understand that your design applies to rear lamps. The measuremen for the illuminated area of a rear lamp as specified in SAE J585e, 'Tail Lamps (Rear Position Lamps),' for example, is stated in part as follows:; >>>...'To be considered visible, the lamp must provide an unobstructe projected illuminated area of outer lens surface....'<<<; This applies to the installation requirements, i.e., the device as use on a vehicle. It is not part of the laboratory test procedure.; Further, with regard to photometric requirements of a lamp, n measurement for the illuminated area of a rear lamp is specified in SAE test procedures.; In summary, Standard No. 108 does not prohibit Lucas from manufacturin the lamp in question, but the vehicle manufacturer must be careful to insure that the lamp, when installed, conforms to the standard's requirements for visibility of lens area.; Sincerely, Frank Berndt, Chief Counsel |
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ID: aiam1609OpenMr. J. A. Shebiel, Vice President, Northland Equipment Co., Inc., 412 West State Street, Janesville, WI 53545; Mr. J. A. Shebiel Vice President Northland Equipment Co. Inc. 412 West State Street Janesville WI 53545; Dear Mr. Shebiel: This is in reply to your letter of August 19, 1974, which refers to ou letter of July 17, 1974, to the Distributors' Association regarding the use of the incomplete vehicle manufacturer's gross vehicle weight rating by a final- stage manufacturer who adds an additional axle to the vehicle. Our position in that letter was that a gross vehicle weight rating which was so unrelated to vehicle capacity that it suggests a motive such as avoidance of an applicable standard could be construed as a false and misleading certification or a potential safety related defect. You point out that this result works a hardship on persons who customarily add axles because they are unable to determine an appropriate gross vehicle weight rating to use for Certification purposes.; The NHTSA's concern, and indeed the thrust of the Certificatio requirements, is that vehicles as manufactured will conform to all applicable safety standards when carrying expected loads. However, we are not unmindful, and do not wish to give the impression of ignoring, practical problems connected with compliance with the requirements. Our hope is that the industries involved could collectively resolve their mutual problems, preferable without, but possible with, assistance from Government regulation. We would certainly consider any concrete proposals for amending the regulations applicable to incomplete and intermediate vehicle manufacturers to resolve this problem, as long as such proposals do not abrogate the primary purposes of the requirements. The use of the incomplete vehicle manufacturer's weight ratings is not satisfactory in this respect. We would welcome any future communications you or the various associations might have with respect to possible solutions to this problem, and will be happy to meet with you at your request.; Yours truly, Richard B. Dyson, Acting Chief Counsel |
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ID: aiam3264OpenMr. James E. Forrester, Manager of Engineering Services, Truck Body and Equipment Association, Inc., 5530 Wisconsin Avenue, Suite 1220, Washington, DC 20015; Mr. James E. Forrester Manager of Engineering Services Truck Body and Equipment Association Inc. 5530 Wisconsin Avenue Suite 1220 Washington DC 20015; Dear Mr. Forrester: This responds to your March 17, 1980, letter asking for a interpretation of the certification label requirements as they apply to a manufacturer who performs some manufacturing operation on a stripped chassis. You indicated in your letter that the stripped chassis is not a chassis-cab and, therefore, does not have a certification label. You further stated that the second manufacturer's modification of the stripped chassis do (sic) not convert it to a chassis-cab.; The chassis certification label requirements of Part 567 *Certification*, and Part 568, *Vehicles Manufactured in Two or More Stages*, apply only to chassis-cabs as that term is defined in Part 567. Since the incomplete vehicle to which you refer is not a chassis-cab at either of the first two stages of its manufacture, it is not required to be labeled. The second manufacturer is required to amend the incomplete vehicle document where necessary to show the effects of its changes to the incomplete vehicle.; Your second question poses a similar hypothetical, except that th second manufacturer completes the incomplete vehicle to the point where it is a chassis-cab. In this instance, the second manufacturer is required to attach the chassis-cab certification label. Also, all necessary amendments must be made in the incomplete vehicle document.; Sincerely, Frank Berndt, Chief Counsel |
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ID: aiam1259OpenMr. Arthur G. Vara, Sr., Octopus Road Safety Devices, Inc., 53 Clark Street, Hamburg, New York 14075; Mr. Arthur G. Vara Sr. Octopus Road Safety Devices Inc. 53 Clark Street Hamburg New York 14075; Dear Mr. Vara: This is in response to your September 4, 1973, petition for rule makin to amend Standard 125, *Warning devices*, to permit the triangular portion of the device to tilt to a position of 30 degrees from the vertical when subjected to winds of 40 mph from any direction for 3 minutes.; The present standard permits 10 degrees tilt under these condition Rowland Development Corporation of Kensington, Connecticut, and Safety Triangles Company of Phoenix, Arizona, have also requested modification of the tilt rule to permit 30 degrees movement. The NHTSA determined that such tilting distorted the distinctive shape of the equilateral triangle and reduced its reflective characteristics. There factors outweighed the claimed benefits of the proposed change. The NHTSA published its decision in the Federal Register on January 30, 1973 (Docket No. 4-2, Notice 6, 38 F.R. 2760).; We have considered your phone calls and your letters of July 25, 1973 August 4, 1973, and September 4, 1973, to the Office of Operating Systems. One letter enclosed a report dated July 13, 1973, which indicates that your device may tilt as much as 80 degrees, which distorts its appearance and reduces its reflective ability. The NHTSA has concluded that the rapid 'flickering' movement which you consider a desirable feature of your device does not outweigh these disadvantages. Therefore, in conformity with our response to earlier petitions for a 30 degrees tilt, your petition is denies. A copy of the previous denial is enclosed for your information.; Sincerely, Robert L. Carter, Associate Administrator, Motor Vehicl Programs; |
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ID: aiam0018OpenMr. Roddy Williams Container Enterprise 3900 Paris Road P.O. Box 1098 Chalmette, LA 70044-1098; Mr. Roddy Williams Container Enterprise 3900 Paris Road P.O. Box 1098 Chalmette LA 70044-1098; "Dear Mr. Williams: This responds to your letter that asked whethe your company is permitted to assign its own Vehicle Identification Numbers (VINs) pursuant to Federal Motor Vehicle Safety Standard No. 115, Vehicle Identification Number--Basic Requirements (49 CFR 571.115) to trailers that it 'remanufactures' from previously used trailers. The answer is that a company that performs the remanufacturing operations described in your letter may assign a new VIN to its remanufactured trailers. By doing so, however, the trailers would be treated as newly manufactured trailers for the purposes of this agency's safety standards and regulations. Among other things, this would mean that your company would be required to certify that the trailers comply with all applicable safety standards in effect as of the date of the remanufacturing operations, including the lighting, tire, and brake standards applicable to new trailers. In a telephone conversation with Dorothy Nakama of my staff, you stated that your company, Container Enterprise, works on trailers that were used to carry cargo containers. You stated that approximately 90% of the trailers that Container Enterprise works on were originally built between 1974 and 1979. Container Enterprise takes used container chassis that are 23 feet long and removes the axles and half of the crossmembers on the original frame. Container Enterprise then manufactures a 12 foot subframe and reinstalls the used axles on this subframe. The subframe is then attached to the container chassis, extending its chassis length to 27 feet. The conversion allows the chassis to slide open or closed. You stated that upon completion of this process, Container Enterprise will issue 'a new manufacturer plate with a new VIN number' and date of remanufacture. The National Traffic and Motor Vehicle Safety Act (15 U.S.C. 1381 et seq.) authorizes this agency to issue safety standards applicable to new motor vehicles and new items of motor vehicle equipment. We have exercised this authority to establish Standard No. 115, which applies to all new vehicles. S4.1 of Standard No. 115 specifies that vehicles manufactured in one stage shall have a VIN assigned by the vehicle manufacturer and S4.5 specifies that the assigned VIN shall appear clearly and indelibly on the vehicle. Thus, the only person that can assign a VIN to a vehicle is the vehicle's manufacturer. The question then is whether your company's 'remanufacturing' operations are substantial enough that the remanufactured trailers should be considered to be new vehicles and the manufacturer of those vehicles would be your company, instead of the original manufacturer of the trailer. NHTSA's regulations specifically address the question of when trailers produced by combining new components (the subframe fabricated by your company) and used components (the parts of the used container chassis) are considered to be new trailers. 49 CFR 571.7(f) states that when new and used components are used in trailer manufacture, the trailer will be considered 'newly manufactured' unless the following three conditions are met. First, the trailer running gear assembly, which includes the axle(s), wheels, braking and suspension, is not new, and was taken from an existing trailer. Second, the existing trailer's identity is continued in the reassembled vehicle with respect to the Vehicle Identification Number. Third, the existing trailer is owned or leased by the user of the reassembled vehicle. You have stated that your company would assign new VINs to the trailers it remanufactures. Upon doing so, the second condition in 571.7(f), continuing use of the original VIN, would not be met. Therefore, the trailers 'remanufactured' by your company would be considered to be newly manufactured. Your company, as the manufacturer, must certify that these trailers comply with all applicable Federal motor vehicle safety standards in effect at the time of the remanufacture. This means that, in addition to complying with the 1991 requirements of Standard No. 115, your company would be required to certify that the trailers comply with the 1991 versions of the lighting standard (Standard No. 108), the tire and rim standard (Standard No. 120), and the air brake standard (Standard No. 121), to name a few examples of applicable standards. To assist you in making any such certifications, I am enclosing a brochure that briefly describes each of the safety standards and an information sheet for new manufacturers of motor vehicles that explains how to get copies of our standards and regulations. Your letter also referred to U. S. Department of the Treasury Publication 510 on Excise Taxes. We can only tell you that your remanufactured trailers with new VINs would be considered new vehicles for the purposes of the Safety Act and the Federal motor vehicle safety standards. If you have any questions about the trailers for purposes of excise taxes, you should contact the Internal Revenue Service. Their District Office for Louisiana is located at 500 Camp Street, New Orleans, LA 70130. I hope this information is helpful. If you have any additional questions, please feel free to contact Ms. Dorothy Nakama of my staff at this address or by telephone at (202) 366-2992. Sincerely, Paul Jackson Rice Chief Counsel Enclosures"; |
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ID: aiam5236OpenMr. Richard G. Meier Deputy Assistant Office of the U.S. Trade Representative 600 17th Street, N.W. Washington, DC 20506; Mr. Richard G. Meier Deputy Assistant Office of the U.S. Trade Representative 600 17th Street N.W. Washington DC 20506; Dear Mr. Meier: This letter follows up on the July 23, 1993, meeting i which you and Ms. Suzanne Troje discussed with representatives of this agency concerns of the Mexican Government that tires produced in Mexico for sale in the U.S. must be labeled in English and tested in Texas. We would like to explain our regulations and correct an apparent misimpression of the Mexican government. Tires manufactured for sale in the United States must be labeled with safety and consumer information that is required by statute (the National Traffic and Motor Vehicle Safety Act) and by regulation. The regulations require that the information be in English. There is no available exception to the English labeling requirement for the safety information, but there is an exception to the consumer information requirement of our uniform tire quality grading standards (UTQGS, copy enclosed). The UTQGS do not apply to 'limited production tires,' as defined in that standard. This exception could provide the basis for a Mexican tire manufacturer to import a limited number of tires into this country to assess the market. However, the annual importation of that tire into the U.S. must not exceed 15,000 tires. The UTQGS do not require that manufacturers test their tires at this agency's test track at San Angelo, Texas. Manufacturers may test their tires where they choose, and may even choose not to test their products at all. However, the specification in the UTQGS regulations that testing is done at San Angelo means that NHTSA must use that track in any compliance testing of tires. In order to protect themselves against the possibility that the agency will find a noncompliance based on testing at San Angelo and initiate an enforcement action, it would be prudent for tire manufacturers to base their assigned grades on their own testing at San Angelo or on some substitute means whose results demonstrably correlate with the results of testing at San Angelo. We hope this information is helpful. For your information, I have attached a general information sheet discussing NHTSA's requirements for new manufacturers. Please let us know if we can be of further assistance. Sincerely, John Womack Acting Chief Counsel Enclosure; |
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ID: aiam3248OpenMs. Wendy Garner, Kenworth Truck Co., Box 1000, Kirkland, Washington 98033; Ms. Wendy Garner Kenworth Truck Co. Box 1000 Kirkland Washington 98033; Dear Ms. Garner: This responds to your telephone conversation with Mr. Schwartz of m office in which you asked whether net brake horsepower must be decipherable from the engine type encoded in the vehicle identification number (VIN) of heavy trucks.; The *precise* net brake horsepower of heavy trucks (or any othe vehicle class or type) need not be encoded. This was the point which the agency was making in its March 22, 1979 (44 FR 17489) statement that:; >>>(W)hile net brake horsepower is among the characteristics to b considered in establishing an engine type, there is no requirement that it be encoded in the engine type code. In some instances such as with heavy truck engines, encodement would not be practicable.<<<; However, except as provided below, the *range* of net brake horsepowe must be encoded to differentiate engine types as required by section 4.5.2 of Federal Motor Vehicle Safety Standard 115. To define the acceptable range of net brake horsepower for a single engine type, the agency made a clarifying amendment to that section (February 25, 1980, 45 FR 12257). Footnote 1 to Table I provides that otherwise identical engines having net brake horsepower ratings that vary up to plus or minus 10 percent, may be treated as being of the same engine type.; The exception to the requirement to encode the range of net brak horsepower involves manufacturers which intend to utilize more than 33 engine types whose horsepower ranges fall outside the plus or minus 10 percent parameters. These manufacturers will be unable to encode their current or anticipated engine types utilizing only a singe VIN position since there are 33 separate characters authorized to be used for each VIN position. Consequently, they need not encode net brake horsepower in any way. The agency did not intend that more than one VIN position be used to encode net brake horsepower. Using more than one position would be impracticable at this time given the amount of information that needs to be encoded in the VIN.; Please contact Mr. Schwartz should you(sic) have any further question concerning this subject.; Sincerely, Frank Berndt, 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.