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
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ID: aiam0700OpenMr. William C. McCamant, Washington Representative, Automotive Service Industry Association, 1725 K Street, N.W., Washington, DC 20006; Mr. William C. McCamant Washington Representative Automotive Service Industry Association 1725 K Street N.W. Washington DC 20006; Dear Mr. McCamant: This is in reply to your letter of April 21, 1972, in which you reques clarification as to the application of the Tire Identification and Recordkeeping regulations (49 CFR Part 574) to your members under various circumstances described therein.; Generally persons other than tire manufacturers who have obligation under the Tire I.D. regulations are motor vehicle manufacturers and tire distributors and dealers. A person adding tires to a vehicle of which he is either an incomplete vehicle manufacturer, intermediate manufacturer, or final-stage manufacturer, as those terms are defined in 49 CFR 568.3, will be a vehicle manufacturer subject to the requirements of 574.10. Those persons adding tires as part of modifications to used vehicles will be tire dealers, and subject to the requirements of 574.8.; With respect to the three situations you list, in those cases where th tires have already been installed on the vehicle when your member receives it (Case No. 1), your member would not be adding tires to the vehicle and would not be responsible for compliance with the Tire I.D. requirements. In those cases where the tires are added or changed by an independent tire dealer, if the independent dealer is actually doing business with your member rather than with the owner of the vehicle, and if your member is an incomplete, intermediate, or final-stage manufacturer, he must comply with 574.10. If he does not fall within any of these categories he will be a tire dealer subject to 574.8. If the tire dealer is dealing independently with the owner of the vehicle, your member will not be the party adding tires to the vehicle, and will not be subject to the requirements. With regard to the situation where your member puts tires on a frame or vehicle as part of a package deal (Case No. 3), if he is either an incomplete vehicle, intermediate or final-stage manufacturer he will be required to comply with the requirements of 574.10. If he does not fall within these categories, he will be a tire dealer and subject to section 574.8.; Assuming your member must record the name of the first purchaser as manufacturer or dealer, you have asked whether he may use the name of the dealer to whom he delivers the vehicle as the first purchaser, when that is the case, as he frequently does not know the name of the first purchaser for a purpose other than resale. You refer to our March 14, 1972, letter to you in which we stated that a dealer's name could be used in meeting the 'Owner's List' requirement of the Defect Reports regulations (49 CFR Part 573) when the name of the dealer was the only name which the manufacturer had. For the purposes of the Tire I.D. requirements, the manufacturer must obtain and use the name of the actual purchaser for a purpose other than resale. It is not sufficient under this requirement for the name of the dealer to be used. Section 113(f) of the National Traffic and Motor Vehicle Safety Act (15 U.S.C. 1402(f), which became effective November 18, 1970, provides that.(sic) 'Every manufacturer of motor vehicles or tires shall maintain records of the names and addresses of the first purchaser (other than a dealer or distributor) of motor vehicles or tires produced by that manufacturer.' In our view this provision requires the manufacturer of a multi-stage vehicle who adds the tires to the vehicle to obtain the names of such purchasers, even if the names must be obtained from dealers. Our letter of March 14 should not be read to absolve your members who are such manufacturers from meeting this requirement. What that letter allows is simply that in those cases where manufacturers have not, at the time they must compile an owner list, obtained the names of first purchasers, they may use the name of the dealer and not be in violation of the 'Owner's List' requirement. This may be done, however, only until they can obtain the actual first purchaser's name. We regret that this point was not made clear in our March 14 letter, and that letter is hereby modified in this regard.; Concerning your question as to the conditions under which automotiv wholesalers and warehouse distributors must keep Tire Identification records, if the automotive wholesaler or warehouse distributor is not selling tires directly to the user of the vehicle he need only ensure that the dealer or distributor to whom he sells the tires has a means of recording the required information so that it may be forwarded to the tire manufacturer (section 574.8(c)). In the event the automotive wholesaler or warehouse distributor sells tires to a user, then he must record the information specified in S 574.7(a) and forward that information to the tire manufacturer.; Sincerely, Lawrence R. Schneider, Chief Counsel |
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ID: aiam3985OpenMr. William Pesce, 8 P Origionals, 2892 Crownview Dr., Rancho Palos Verdes, CA 90274; Mr. William Pesce 8 P Origionals 2892 Crownview Dr. Rancho Palos Verdes CA 90274; Dear Mr. Pesce: Thank you for your May 18, 1985 letter inquiring about the existence o any Federal safety requirements applicable to your projected sale of colored windshield wiper blades.; Under the National Traffic and Motor Vehicle Safety Act, this agenc has issued Federal Motor Vehicle Safety Standard No. 104, *Windshield Wiping and Washing System*, applicable to new motor vehicles. While this standard does not regulate wiper color, it does among other things, require that a wiping system clear a minimum percentage of a vehicle's windshield; In addition, Standard No 107, *Reflecting Surfaces*, also applies t new motor vehicles. This standard specifies reflecting surface requirements for certain components, including windshield wiper blades, in the driver's field of view. Its purpose is to reduce the likelihood the unacceptable glare from reflecting surfaces will hinder safe and normal operation of the vehicle.; If a new vehicle equipped with your blade did not comply with Standar No. 104 or Standard No. 107 due to some aspect of that blade, the sale of that car to the public would be a violation of the prohibition in section 108(a)(1)(A) of the Act against the sale of noncomplying vehicles.; As to used vehicles, you should be aware that section 108(a)(2)(A) o the Act prohibits manufacturers, distributors, dealers and vehicle repair businesses form knowingly rendering inoperative equipment or elements of design installed on a vehicle under Federal motor vehicle safety standards. Care should be taken that the installation of your product would not have that effect. A rendering inoperative might occur if, for example, your blade were not large enough to enable the wiping system to clear a sufficient area of the windshield. We urge you therefore to ensure that the substitution of your blade for an original equipment blade provided by a vehicle manufacturer would enable the wiping system to continue to perform as required by Standard No. 104, and would not produce unacceptable glare in the driver's field of view, as required by Standard No. 107.; I hope this information is helpful. Sincerely, Jeffrey R. Miller, Chief Counsel |
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ID: aiam5152OpenMs. Jane L. Dawson Specifications Engineer Thomas Built Buses, Inc. P.O. Box 2450 1408 Courtesy Rd. High Point, NC 27261; Ms. Jane L. Dawson Specifications Engineer Thomas Built Buses Inc. P.O. Box 2450 1408 Courtesy Rd. High Point NC 27261; Dear Ms. Dawson: This responds to your letter of March 5, 1993 askin if an exterior handle is required for emergency exit windows under the recent final rule amending Standard No. 217, Bus Window Retention and Release (November 2, 1992, 57 FR 49413). As explained below, the answer is no. The final rule added a new section S5.3.3.2 to Standard No. 217 which reads: each school bus emergency exit window shall allow manual release of the exit by a single person, from inside the passenger compartment (emphasis added). Thus, unlike doors and roof exits, a release mechanism is not required on the outside of emergency exit windows. I hope you find this information helpful. If you have any other questions, please contact Mary Versailles of my staff at this address or by phone at (202) 366-2992. Sincerely, John Womack Acting Chief Counsel; |
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ID: aiam2697OpenDavid E. Martin, Director, Automotive Safety Engineering, General Motors Corporation, General Motors Technical Center, Warren, MI 48090; David E. Martin Director Automotive Safety Engineering General Motors Corporation General Motors Technical Center Warren MI 48090; Dear Mr. Martin: This is in reply to your letter of June 3, 1977, to Ms. Joan Claybrook requesting an interpretation of whether the release action of your 'c-ring' seat belt latch mechanism qualifies as a push button action as specified in paragraph S7.2(c) of Federal Motor Vehicle Safety Standard No. 208, Occupant Crash Protection.; Your efforts to improve the comfort and convenience of belt system thereby increasing the likelihood that they will be used is to be commended. I must point out, however, that the primary purpose of the requirement in paragraph S7.2(c) is to standardize the release method of all seat belts. This reduces the likelihood that occupants will become confused as to how to release a belt in a strange car or in an emergency situation.; We have reviewed the operation of your 'c-ring' and conclude that th action necessary to release the mechanism does not constitute push botton (sic) action. However, incorporation of a push button release, similar to the design being used in Saab automobiles, would bring your 'c-ring' into conformance with S7.2(c) and permit its use.; Sincerely, Robert L. Carter, Associate Administrator, Motor Vehicl Programs.; |
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ID: aiam0350OpenMr. Lawrence Petterson, Hicks Oil Company, 215 1/2 East Main Street, Pipestone, MN 56164; Mr. Lawrence Petterson Hicks Oil Company 215 1/2 East Main Street Pipestone MN 56164; Dear Mr. Petterson: This is in reply to your letter of April 28, 1971. Under Part 574, th tire identification number may be placed on the side of the top cap area or may be branded into the tire in accordance with the regulation. If the top cap area is used, the number should be as close to the sidewall as is feasible so that the number will remain legible as long as possible. See the enclosed amendment on this subject (Docket No. 70-12, Notice No. 9).; Sincerely, Lawrence R. Schneider, Acting Chief Counsel |
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ID: aiam2443OpenMr. George R. Semark, Manager, Vehicle Safety Activities, Sheller-Globe Corporation, Vehicle Planning and Development Center, 3555 St. Johns Avenue, Lima, OH 45804; Mr. George R. Semark Manager Vehicle Safety Activities Sheller-Globe Corporation Vehicle Planning and Development Center 3555 St. Johns Avenue Lima OH 45804; Dear Mr. Semark: This responds to Sheller-Globe Corporation's August 31, 1976, questio whether 5 described intersections in a bus body qualify as 'body panel joints' subject to the requirements of Standard No. 221, *School Bus Body Joint Strength*.; The windshield fence that you describe in section A of your lette connects the window glazing seal to the bus body and is considered to be a portion of the window by the NHTSA. Windows are excluded from the definition of 'body panel joint' found in S4 of the standard. Therefore, the fence would be excluded from the requirements of the standard.; The 'trim molding' described in section B of your letter constitutes body panel that encloses occupant space. The fact that the trim is decorative does not place it within the exclusion of 'spaces designed for ventilation or other functional purpose.' Since the 'trim molding' is a body panel and is connected to a body component, it creates a joint subject to the requirements of the standard. The fact that the molding, like every other part of the bus, has a function does not exclude it from the ambit of the joint requirement under the exception for 'ventilation or other functional purpose.'; In section C of your letter, you acknowledge that the joint where th skirt panel connects to the outside upper body panel falls within the ambit of the standard. You request an exception from the standard's requirements for this joint based upon a perceived lack of safety hazards resulting from failure of this joint in a crash situation.; To implement the Congressional mandate for school bus safety, the NHTS drafted Standard No. 221 to cover all joints that are potentially dangerous in a crash situation. The agency adopted this broad coverage of joints to avoid the more piecemeal approach of analyzing each joint for possible safety problems, because it is impracticable to test every joint in every possible accident configuration. Therefore, since the joint you describe falls within the parameters of the standard, it must meet the requirements specified.; The joint described in section D of your letter where the vent eve connect to the outside roof panel is a joint within the definition of the standard. The outside roof panel is a 'body panel' as defined in S4. The junction where a 'body panel' connects to a 'body component,' the vent eves, constitutes a joint regulated by the standard.; With regard to section E of your letter, the NHTSA agrees that th joint where the outside and inside lower panels connect is within the scope of the standard. Whether or not the joint itself is covered by trim molding is not relevant to its status. It is still a joint within the definition of the standard and subject to all of the requirements therein.; I trust these interpretations fully answer your questions. Sincerely, Frank A. Berndt, Acting Chief Counsel |
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ID: aiam5386OpenMr. and Mrs. Hal Sullivan 33891 Calle Borrego San Juan Capistrano, CA 92675; Mr. and Mrs. Hal Sullivan 33891 Calle Borrego San Juan Capistrano CA 92675; "Dear Mr. and Mrs. Sullivan: This responds to your letter to Davi Elias, formerly of this office, requesting an interpretation of the term 'rated cargo load' used in 49 CFR 567.5. I apologize for the delay in responding. You state in your letter that you purchased a 1992 Pace Arrow motor home from Fleetwood Motor Homes of California, Inc. You state that, if this motor home is equipped with 'the identical factory optional HWH hydraulic jacks,' it will exceed its gross vehicle weight rating (GVWR) when the available water tanks are filled to capacity. You characterize this as 'seriously inadequate carrying capacity,' and ask if this violates NHTSA's regulations. As explained below, if a vehicle exceeds its GVWR when loaded with its intended cargo, the manufacturer may be subject to civil penalties. By way of background, 114 of the National Traffic and Motor Vehicle Safety Act requires each motor vehicle manufacturer to certify the compliance of its new vehicles with all applicable Federal motor vehicle safety standards. NHTSA issued its vehicle certification regulation (49 CFR Part 567) to implement 114. Section 108(a)(1)(E) of the Safety Act prohibits any person from failing to comply with any regulation issued under 114. Under 109 of the Safety Act, violations of 108(a)(1)(E) are subject to a civil penalty of up to $1,000 for each violation. NHTSA's certification regulation specifies the content of the certification label, and requires manufacturers to assign a GVWR to its new vehicles. The term GVWR is defined in 49 CFR 571.3 as 'the value specified by the manufacturer as the loaded weight of a single vehicle.' The GVWR informs vehicle owners how heavily the vehicle may safely be loaded. It also affects the vehicle's loading and other test conditions for the performance tests to ascertain whether the vehicle complies with applicable safety standards. The only express regulatory limitation on the GVWR that manufacturers may assign to their vehicles is set forth in 49 CFR 567.4(g)(3), which provides that the assigned GVWR 'shall not be less than the sum of the unloaded vehicle weight, rated cargo load, and 150 pounds times the vehicle's designated seating capacity.' (Emphasis added.) There is no express definition for the term 'rated cargo load' in Part 567 or elsewhere in NHTSA's regulations. However, NHTSA expects the GVWR (which includes rated cargo load) to reflect a manufacturer's good-faith evaluation of the vehicle's size, weight, load-carrying capacity and intended use. NHTSA is concerned about the potentially adverse effects on safety that might result from assigning too low a GVWR to a vehicle. NHTSA recognizes that vehicle overloading may create a serious safety problem and will take appropriate action against any manufacturer whose vehicle, when operated in its intended manner, exceeds the assigned GVWR. Thank you for bringing this matter about the Pace Arrow to our attention. NHTSA's Office of Vehicle Safety Compliance will be contacting you for more information about your experience with the vehicle. Meanwhile, if you have further questions, please contact Deirdre Fujita of my staff at (202) 366-2992. Sincerely, John Womack Acting Chief Counsel"; |
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ID: aiam0184OpenMr. Erich K. Dorfner, Product Development Manager, Thompson Aircraft Tire Corporation, 160 Beacon Street, South San Francisco, California 94131; Mr. Erich K. Dorfner Product Development Manager Thompson Aircraft Tire Corporation 160 Beacon Street South San Francisco California 94131; Dear Mr. Dorfner: In response to your letter of November 6, 1969, the Department o Transportation hereby assigns number *211* to the Thompson Aircraft Tire Corporation, South San Francisco, California, as its approved code mark. The approved code mark is for use in identifying the tire manufacturer in accordance with S4.3 of the Federal Motor Vehicle Safety Standard No. 109 and the National Traffic and Motor Vehicle Act of !966 (15 USC 1421(1)).; You are cautioned that the approved code mark at the present time i for use only on new pneumatic passenger car tires.; Sincerely, Roger H. Compton, Director, Office of Standards on Acciden Avoidance, Motor Vehicle Safety Performance Service; |
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ID: aiam2013OpenMr. John H. Mueller, The Weatherhead Company, 300 East 131st Street, Cleveland, Ohio 44108; Mr. John H. Mueller The Weatherhead Company 300 East 131st Street Cleveland Ohio 44108; Dear Mr. Mueller: #Please forgive the delay in responding to you letter of March 25,1975, which suggested an inconsistency in the labeling requirements of Federal Motor Vehicle Safety Standard No. 106-74, *Brake Hoses*. #S5.1 of the standard requires each hydraulic brake hose assembly to be equipped with end fittings which are attached by means of crimping or swaging. You have correctly pointed out that S5.2.3 specifies labeling requirements for 'hydraulic' end fittings which are neither crimped nor swaged, even though at present there are no hydraulic fittings, that fit that description. This language appears as part of S5.2 because S5.2 is incorporated by reference in S7.2 and S9.1, the labeling requirements for hose, fittings, and assemblies used in air and vacuum brake systems, respectively. Although there is thus no inconsistency, the National Highway Traffic Safety Administration is considering a clarifying amendment along the lines you have suggested, which would eliminate S5.2.3 and specify the labeling requirements directly in S7.2 and S9.1. #Thank you for pointing out this potential source of confusion. #Sincerely, Frank A. Berndt, Acting Chief Counsel; |
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ID: aiam4597OpenThe Honorable Leon E. Panetta House of Representatives Washington, DC 20515; The Honorable Leon E. Panetta House of Representatives Washington DC 20515; "Dear Mr. Panetta: This letter responds to your inquiry on behalf o your constituent, Mr. Botelho. You asked whether Federal regulations require mirrors to be placed on the right side of vehicles and whether such mirrors must be convex in nature. Mr. Botelho expressed his objection to requiring convex mirrors, because he believes convex mirrors distort images and cause objects to appear further away than they actually are. I am pleased to have this opportunity to explain this requirement and its background for you. Standard No. 111, Rearview Mirrors (49 CFR /571.111, copy enclosed)) establishes performance and location requirements for the rearview mirrors installed in new vehicles. Specifically, a passenger car whose inside rearview mirror does not meet the field of view requirements of section S5.1.1 must have an outside mirror on the passenger side of either unit magnification or a convex mirror. In a September 2, 1982 final rule amending Standard No. 111, the National Highway Traffic Safety Administration (NHTSA) explained that convex mirrors offer safety benefits by providing an expanded field of view to the rear, thereby reducing the need for the driver to turn around to view the rear directly. On the other hand, some users of convex mirrors that were used to the images shown by conventional plane mirrors incorrectly perceived that the object shown in the convex mirror was further to the rear than it actually was. Additionally, some users of convex mirrors experienced double vision, eyestrain, and nausea. After considering these potential advantages and disadvantages, NHTSA amended Standard No. 111 so that it does not require any vehicle to be equipped with convex mirrors, but it permits the use of convex mirrors on the passenger side of cars and light trucks, provided that the convex mirror meets certain additional requirements. The additional requirements applicable to convex mirrors on the passenger side of cars and light trucks are: 1. A maximum radius of curvature for the convex mirror. This limits the range of convexities to which drivers will be exposed. It also ensures that the field of view will be noticeably greater than for a plane mirror. 2. A minimum radius of curvature for the convex mirror. This ensures that the image size in the convex mirror will be adequate and distortion will not be excessive. 3. A stringent maximum permissible variation in the radius of curvature over the surface of the convex mirror. This requirement, which is more stringent than the European requirement in this area, also ensures that convex mirrors will have low distortion. 4. A warning etched on the convex mirror that objects shown in the mirror are closer than they appear. This requirement ensures that the driver who may not be familiar with convex mirrors will not be misled by the image size of the convex mirror and the apparent distance to the object. Hence, we agree with Mr. Botelho that the areas he has identified are potential problems unique to convex mirrors. However, our standard includes special requirements for convex mirrors to minimize the potential problems identified by Mr. Botelho and other potential problems that were identified in research studies of convex mirrors. We are not aware of any data showing that convex mirrors that comply with those special requirements present any unacceptable problems for drivers. I hope this information is helpful. If you have any further questions or need any additional information on this subject, please let me know. Sincerely, Erika Z. Jones Chief Counsel Enclosure"; |
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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.