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: aiam2475OpenMr. R. E. Weil, Exterior Lighting Development, Chrysler Corporation, P.O. Box 1118, Detroit, MI, 48231; Mr. R. E. Weil Exterior Lighting Development Chrysler Corporation P.O. Box 1118 Detroit MI 48231; Dear Mr. Weil: This is in reply to your letter of September 16, 1976, to Mr. Brooks o this agency on photometric test requirements of multiple compartment and multiple lamp configurations. You have asked for our concurrence on two interpretations of Standard No. 108, as discussed below.; In your 'example 1', on vehicles designed with a two lamp system parking and (or taillamp) and turn signal functions are combined in each lamp of the two lamp system. You have asked whether the second lamp in this system would be treated as supplemental and need not meet the photometric requirements for required lamps.; The answer is no. As you are aware the photometric requirements o multiple lamps or multiple compartment lamps, where a tail or parking lamp is combined with the turn signal lamp, are partially determined by Note 4 to SAE Standard J588e *Turn Signal Lamps*. Note 4 establishes permissible ratios of intensity between functions *i*. *e*. that the intensity of the tail or parking lamps shall not be so great as to diminish the effectiveness of the turn signal function. Where two lamps are used and the distance between filament centers does not exceed 22 inches (as appears to be the case here) the combination of the lamps must be used to meet the photometric requirements for the corresponding number of lighted sections. (Paragraphs 3.1 of J585d, J588e). Further, the ratio of the turn signal to the tail or parking lamps must be computed with all the lamps lighted (Note 4). With reference to those vehicles designed with a two-lamp system (your example 1), your first answer is the correct one, the lamps would be photometered together to meet the two compartment requirements for the two lamp functions performed, as specified in Table 1 of Standard No. 108.; With respect to your example 2, a multiple compartment lamp with on compartment performing turn signal and parking or tail lamp functions, and the other portion the function of parking or tail lamp only, photometric requirements for the tail lamp function are determined on the basis of the output of the two compartments. The single compartment parking lamp may, however, be treated as a 'supplemental' lamp, except that the candlepower ratios (with turn signal lamp) must be met with both parking lamp compartments illuminated.; Sincerely, Frank A. Berndt, Acting Chief Counsel |
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ID: aiam0366OpenMrs. Annemarie Shelness, Physicians for Automotive Safety, 50 Union Avenue, Irvington, NJ 07111; Mrs. Annemarie Shelness Physicians for Automotive Safety 50 Union Avenue Irvington NJ 07111; Dear Mrs. Shelness: Thank you for your letter of May 24, 1971, informing us of Mr. Hurley' Safe-Trip-Seat and inquiring about enforcement of Standard No. 209 concerning a non-complying Hankscraft child harness.; Mr. Hurley sent us a letter on April 10, 1971, informing us of hi device. Our letter to him was sent out on May 10, 1971, so he had not received it when he wrote to you. I believe we have adequately informed him of his lack of compliance with Standard No. 213 and the penalties involved if he does not. A copy of our letter to him is enclosed for your information. Our compliance personnel were also alerted on the Safe-Trip-Seat.; Hankscraft was notified in a letter dated March 23, 1971, of ou position on any child harness (copy enclosed). Please note that we will enforce Standard No. 209 on harnesses advertised in any way to provide any measure of protection in a vehicle accident. We will not enforce the requirements of Standard No. 209 of harnesses which carefully state that they are not intended to protect a child from the effects of an accident.'; A copy of this letter is being forwarded to our compliance personne for appropriate action by them.; Sincerely, Clue D. Ferguson, Director, Office of Crashworthiness, Moto Vehicle Programs; |
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ID: aiam5164OpenMr. Brett J. Higgins 10257 Slater Ave. #103 Fountain Valley, CA 92708; Mr. Brett J. Higgins 10257 Slater Ave. #103 Fountain Valley CA 92708; "Dear Mr. Higgins: This responds to your letter of March 25, 1993 t former Chief Counsel Paul Jackson Rice seeking information on how the laws and regulations administered by this agency would apply to an item of equipment you wish to sell. According to your letter, the item is a special clamp that is applied to the shoulder strap of a seatbelt as an after-market item. The purpose of this clamp is to allow for slack in the shoulder harness section of a seatbelt thus allowing it to be worn more comfortably. I am pleased to have this opportunity to explain our laws and regulations to you. The National Traffic and Motor Vehicle Safety Act (15 U.S.C. 1381 et seq., the Safety Act) authorizes this agency to issue motor vehicle safety standards for new motor vehicles and new items of motor vehicle equipment. We have exercised this authority to establish Standard No. 208, Occupant Crash Protection (49 CFR 571.208). This standard requires new motor vehicles to be equipped with safety belts and requires that those belts meet specified fit and comfort requirements, as set forth in S7 of the standard. However, Standard No. 208 does not apply to aftermarket items that seek to alter belt fit and/or comfort. Hence, you are not required to certify that this device complies with Standard No. 208 before offering the device for sale. In addition, you are not required to get some sort of 'approval' from this agency before offering this device for sale. NHTSA has no authority to '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. As stated above, this device is not subject to any safety standard, so you do not have to make any certification. Although none of our safety standards directly apply to this device, there are several provisions in the Safety Act that are relevant. Manufacturers of motor vehicle equipment such as your belt positioning device are subject to the requirements in sections 151-159 of the Safety Act (15 U.S.C. 1411-1419) concerning the recall and remedy of products with defects related to motor vehicle safety. In addition, use of your product could be affected by section 108(a)(2)(A) of the Safety Act (15 U.S.C. 1397(a)(2)(A)). That section prohibits manufacturer, distributors, dealers, and repair shops from knowingly 'rendering inoperative,' in whole or in part, any device or element of design installed on or in a vehicle in compliance with an applicable safety standard. There are two elements of design in a vehicle that might be 'rendered inoperative' by the use of your belt positioning device. One is the occupant protection afforded by belts that meet the specified fit and comfort requirements. The other element of design that could be rendered inoperative by the use of your device is the burn resistance required by Standard No. 302, Flammability of Interior Materials (49 CFR 571.302). The materials used in the interior of vehicles, including the seat belts, seat backs and cushions, trim panels, and headliner must comply with the burn resistance requirements of Standard No. 302 to reduce deaths and injuries in the event of a fire in the vehicle's interior. If your device renders inoperative the belt fit and comfort requirements specified in Standard No. 208 or does not comply with burn resistance requirements, it could not be installed in a vehicle by any manufacturer, distributor, dealer, or repair shop. I note that NHTSA has received a number of inquiries about devices similar to the one you plan to sell. As we have advised others, this agency is concerned that a belted occupant could inadvertently use such products to introduce excessive slack in the upper torso belt and thereby reduce the effectiveness of that belt. We encourage you to provide instructions with the product that warn users not to introduce excessive slack and provide detailed guidance for users on what is an excessive amount of slack. I have enclosed a general information sheet for new manufacturers that gives a thumbnail sketch of NHTSA's regulations and provides information on how to obtain copies of those regulations. 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 Enclosure"; |
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ID: aiam0736OpenMr. Thomas S. Pieratt, Jr., Executive Secretary, Truck Equipment and Body Distributors Assn., 602 Main Street, Cincinnati, OH 45202; Mr. Thomas S. Pieratt Jr. Executive Secretary Truck Equipment and Body Distributors Assn. 602 Main Street Cincinnati OH 45202; Dear Mr. Pieratt: This is in reply to your letter of June 9 asking whether pole trailer must be certified.; The answer is no. According to 49 CFR S 567.2(a), only motor vehicle to which one or more Federal motor vehicle safety standards are applicable must be certified. The only Federal standard currently in effect that applies to 'trailers', Standard No. 108, specifically exempts 'pole trailers' from its applicability and therefore pole trailers need not be certified.; Your letter of February 23 regarding clearance lamps and identificatio lamps is still under consideration and we hope to provide a response in the near future.; Yours truly, Richard B. Dyson, Assistant Chief Counsel |
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ID: aiam1824OpenHonorable Harley O. Staggers, Chairman, Committee on interstate and Foreign Commerce, House of Representatives, Washington, DC 20515; Honorable Harley O. Staggers Chairman Committee on interstate and Foreign Commerce House of Representatives Washington DC 20515; Dear Mr. Chairman: Thank you for your February 19, 1975, request for our evaluation o Representative B. F. Sisk's concern that the National Highway Traffic Safety Administration (NHTSA) has incorrectly interpreted the definition of 'Motor vehicle' as it appears in S 102 of the National Traffic and Motor Vehicle Safety Act of 1966:; >>>Sec. 102. As used in this title -- (3) 'Motor vehicle' means any vehicle driven or drawn by mechanica power manufactured primarily for use on the public streets, roads, and highways, except any vehicle operated exclusively on a rail or rails.<<<; Mr. Sisk questions whether air-braked trailers which transport far commodities from the field to processing plants or warehouses qualify as motor vehicles under this definition. You also ask for the status of a request for exemption from Standard No. 121, *Air brake systems*, which concerns these vehicles.; The NHTSA has developed criteria for the interpretation of th definition of motor vehicle in the area of heavy vehicles with an off-road function. We conclude that the definition includes vehicles which use the highway on a necessary and recurring basis to move between work sites. We have cited mobile cranes, drill rigs, and towed equipments such as brush chippers and pull-type street sweepers as examples of this motor vehicle class. Following the rationale of necessary and recurring road use, we have excluded from the definition such farm vehicles as mobile feed mixers used strictly in feedlot operations. We believe, however, that the trailers in question have a primary function of highway transportation of bulk produce form the field to the plant.; The Act does not provide a specific exemption for vehicles used i agricultural pursuits. The only reference in the Act to agricultural vehicles is a provision in Title III (as it appeared in 1966) that authorized 'research, development, and testing relating to the safety of machinery used on highways or in connection with the maintenance of highways (with particular emphasis on tractor safety' (S 301). We have interpreted this provision to express Congress' intent that specialized machines which have a strictly non-transportation function (e.g., paving machines, road graders, farm combines, and farm tractors in particular) are not motor vehicles.; With regard to exemption for the trailers in question, we have on request outstanding to exempt these trailers from the parking brake requirements of the standard, because current designs in response to our requirements conflict with the use of these vehicles. We agree that a design that requires parking brake application upon disconnection of the air supply can interfere with storage and marshalling of these vehicles if brake release is not assured after long periods of disconnection. Because of this specific problem in agricultural pursuits, we have decided to undertake rulemaking to exempt these vehicles from that requirement for a year in order to permit manufacturers to modify their designs to solve the problem. We expect to issue a proposal shortly.; I hope that I have been responsive to your questions, and I welcom further opportunity to clarify our interpretations of the National Traffic and Motor Vehicle Safety Act of 1966.; Sincerely, James B. Gregory, Administrator |
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ID: aiam3819OpenMs. Margaret Moore Oba, Hino Motors (U.S.A.) Inc., 200 Park Avenue, Suite 4114-12, New York, New York 10166; Ms. Margaret Moore Oba Hino Motors (U.S.A.) Inc. 200 Park Avenue Suite 4114-12 New York New York 10166; Dear Ms. Oba: This responds to your March 12, 1984 letter regarding the applicabilit of Federal Motor Vehicle Safety Standards to motor vehicles imported into Guam.; Under Sections 102(8), 102(9), and 108(a)(1)(A) of the National Traffi and Motor Vehicle Safety Act of 1966, 15 U.S.C. 1391(8), 1391(9), and 1397(a)(1)(A), motor vehicles introduced into commerce in Guam are subject to Federal Motor Vehicle Safety Standards. In general, the standards apply to the same extent to vehicles imported into Guam as to those imported into the continental U.S. However, as you note in you letter, FMVSS 103 (windshield defrosting and defogging systems) does not apply outside the continental U.S., as specified in section 3 of that standard. See 49 CFR 571.103. Other standards, such as FMVSS 124, which do not limit their applicability to specific geographic areas, apply fully in Guam. Therefore, vehicles imported into Guam must have an accelerator control system which returns the throttle to idle over a temperature range of -40 degrees F. to +125 degrees F.; Sincerely, Frank Berndt, Chief Counsel |
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ID: aiam5534Open9; 9; "Mr. Lance Tunick Vehicle Science Corporation P.O. Box 1015 Golden, C 80402-1015 Dear Mr. Tunick: This is in reply to your letter of April 14, 1995, to Taylor Vinson of this Office asking for an interpretation of Motor Vehicle Safety Standard No. 108. Specifically, you are concerned with the meaning of the words 'outer lens surface' that appear in SAE Standard J586 Stop Lamps for use on Motor Vehicles Less Than 2032 mm in Overall Width FEB84, an SAE standard incorporated by reference in Standard No. 108. These words appear as part of the visibility specifications under the installation requirements. You point out that 'outer lens surface' as not been defined either by the SAE or by NHTSA. You believe that the phrase within the context of SAE J586 can mean 'light emitting surface' as defined in SAE J387, and ask for confirmation. According to Standard No. 108 (SAE J586), 'to be considered visible, the lamp must provide an unobstructed view of the outer lens surface of at least 12.5 square centimeters measured at 45 degrees to the longitudinal axis of the vehicle.' SAE Information Report J387 Terminology - Motor Vehicle Lighting OCT88 defines 'light emitting surface' as 'all or part of the exterior surface of the transparent or translucent lens that encloses the lighting or light signalling device and allows conformance with photometric and calorimetric requirements.' We believe that it would be appropriate to substitute the definition of 'light emitting surface' for 'outer lens surface' in SAE J586. The 'outer lens surface' of J586 appears to mean the same as 'the exterior surface of the transparent or translucent lens' of J387. Thus, stop lamp visibility conformance would require an unobstructed view of the light emitting surface of at least 12.5 square centimeters. As always, Taylor will be happy to answer any further questions you may have on this matter (202-366-5263). Sincerely, John Womack Acting Chief Counsel"; |
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ID: aiam1577OpenMr. David E. Martin, Manager, Automotive Safety Engineering, E- nvironmental Activities Staff, General Motors Technical Center, War- ren, Michigan 48090; Mr. David E. Martin Manager Automotive Safety Engineering E- nvironmental Activities Staff General Motors Technical Center War- ren Michigan 48090; Dear Mr. Martin: We confirm your interpretation of S5.3.2 of Motor Vehicle Safet Standard No. 105-75, expressed in your letter of August 2, 1974, to Dr Gregory, that the engine 'start' position may be used as a check position for indicator lamp function.; The phrase in S5.3.2 'when the ignition (start) switch is in a positio between 'on' ('run') and 'start'' is intended to include both 'on' and 'start' as well as any position between.; Application of the parking brake as an indicator check will no longe be permitted for vehicles manufactured after the effective date of Standard 105-75.; Yours truly, Richard B. Dyson, Acting Chief Counsel |
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ID: aiam4775OpenMr. Jeff Cornell Engineering The Bargman Company 129 Industrial Avenue Coldwater, MI 49036; Mr. Jeff Cornell Engineering The Bargman Company 129 Industrial Avenue Coldwater MI 49036; Dear Mr. Cornell: This is in reply to your letter of July 25, l990, t Taylor Vinson of this Office, asking for clarification of the amendments to Standard No. 108 which were published on May l5 of this year. With reference to section S5.1.1.31, requiring photometric measurement of the entire lamp (and not its individual compartments), you have asked whether this includes the maximums because the preamble to the final rule discussed the requirement only in terms of the minimums. Section S5.1.1.31 refers unqualifiedly to 'measurements' of photometrics, and thus includes maximums as well as minimums. The preamble spoke of minimums only as an example, and was not intended to exclude maximums. I am sorry if this caused some confusion. You have also pointed out that the preamble refers to a minimum luminous lens area of 12 square inches for certain lamps, while the applicable SAE standards that Standard No. 108 incorporates by reference state the minimum as 75 square centimeters, which is only 11.625 square inches. You request a clarification of this point. The appropriate value is 75 square centimeters (11.625 square inches). As a general rule of construction, the text of a standard constitutes the legal requirements which apply. When a value is clearly stated, as in the SAE materials, it takes precedence over an inconsistent value appearing outside the standard, such as in the preamble to the May l5 amendments. The earlier versions of the SAE standards (which the new SAE materials supersede for new motor vehicle equipment) spoke in terms of 12 square inches, and the agency retained this non-metric terminology for purposes of discussing in the preamble the difference between the old and new requirements. Although the SAE could have adopted a value of 77.42 square centimeters (12 square inches) in its new materials, it chose to round the value off to 75 square centimeters, thereby reducing its previously specified minimum luminous lens area by .375 square inch. With respect to another concern, you have presented the hypothetical of the use 'in a molded bumper or fiberglass cap' of three identical single compartment stop lamps per side, none of whose individual luminous lens areas meets the 75 square centimeter requirement, but which, in combination, would exceed it. You have asked whether this would comply with the new requirements. Our answer is no. On May l5, Standard No. 108 was also amended to add a definition for 'Multiple lamp arrangement.'(S3). This is 'an array of two or more separate lamps on each side of the vehicle which operate together to give a signal.' Paragraph 5.3.2 of the newly-incorporated SAE Standard J1398 MAY85 for stop lamps on wide vehicles states in pertinent part that 'The functional lighted lens area of a single lamp . . . and each lamp of a multiple lamp arrangement shall be at least 75 square centimeters.' The configuration you describe is a 'multiple lamp arrangement' and each lamp in the array is subject to the minimum specified requirement. You further ask, if 'the vendor making these lights mounts the individual lights in a molded housing', whether this would create a 'multiple compartment lamp', and if so, 'then how is it different if it is installed into a molded bumper or fiberglass cap.' The definition of 'Multiple compartment lamp' adopted on May 15 states that it is 'a device which gives its indication by two or more separately lighted areas which are joined by one or more common parts, such as a housing or lens.' Multiple lamps cannot be combined to create a 'multiple compartment lamp'. If the individual lamps are mounted in a molded housing, they remain 'an array of two or more separate lamps on the same side of the vehicle which operate together to give a signal', that is to say, a 'multiple lamp arrangement.' The 'lighted areas' of a 'multiple compartment lamp' are something less than a complete lamp, but, when joined by common parts become a single lamp. The configuration you describe is not a 'multiple compartment lamp.' If you have any further questions, we shall be pleased to answer them. Sincerely, Paul Jackson Rice Chief Counsel; |
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ID: aiam1127OpenMorris Poole Auto Sales, U.S. 90 East, Live Oak, FL; Morris Poole Auto Sales U.S. 90 East Live Oak FL; Gentlemen: This is in response to your request for a statement of your odomete disclosure obligations under the Motor Vehicle Information and Cost Savings Act, Public Law 92- 513.; Under the Act, all transferors must make a 'mileage statement' to th transferee. 'Transferor' means any person who transfers his ownership in a motor vehicle by sale, gift, or any means other than by creation of a security interest. This includes a dealer transfering (sic) a new or used vehicle. The only exceptions to the requirement are for vehicles over 16,000 pounds gross weight rating, non-self-propelled vehicles, vehicles 25 years old or older, and new vehicles sold by a dealer to another dealer for resale.; The statement must contain (1) the odometer reading, (2) date o transfer, (3) transferor's name and current address, (4) vehicle identification or serial number, make, model, year, body-type, last plate number, (5) a statement that actual mileage differs from recorded mileage if such is the case and the transferor knows it, and (6) reference to the Motor Vehicle Information and Cost Savings Act with the statement that incorrect information may result in civil liability under it. An example of an adequate statement and format is enclosed for your information.; The federal government does not print these forms but severa commercial printers have prepared Federal disclosure forms for the convenience of dealers. Alternatively, the statement may be included in the bill of sale, or other transfer document. In any case, it must be completed and signed prior to the transfer. Either the original or carbon copy may go to the transferee. It may be advisable to include a second disclosure statement in your form to provide for the odometer disclosure by the buyer on his trade-in vehicle.; Yours truly, Richard B. Dyson, 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.