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: aiam0237OpenMr. Thomas J. McKnight, President, Fleet Cap'n Trailers, Inc., P. O. Box 508, New Bern, NC 28560; Mr. Thomas J. McKnight President Fleet Cap'n Trailers Inc. P. O. Box 508 New Bern NC 28560; Dear Mr. McKnight: This is in reply to your letter of April 29, 1970, to Mr. Rodolfo A Diaz, Acting Associate Director, Motor Vehicle Programs, concerning the location of rear lamps on various models of your trailers.; From a review of the sketch attached to your letter, it appears tha the tail, stop and turn signal lamps mounted on the trailer frame rearward of the fenders will meet the location requirements specified in Table IV of Federal Motor Vehicle Safety Standard No. 108. However, Standard No. 108, by reference to SAE Standard J588d, also requires that '---visibility of the front turn signal to the front and the rear signal to the rear shall not be obstructed by any part of the vehicle throughout the photometric test angles for the lamps.' The photometric test angles for turn signal lamps are specified in Table 2 of SAE Standard J575c. From your sketch it appears that the required visibility of the turn signal lamps, when mounted in the proposed location, would be partially blocked by the framework of the trailer. Mounting the lamps on the rear crossmember may therefore be necessary to provide the required unobstructed visibility.; For your information I am enclosing copies of Standard No. 108, SA Standard J588d and SAE Standard J575c.; Sincerely, Roger H. Compton, Director, Office of Operating Systems Motor Vehicle Programs; |
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ID: aiam5035OpenHerr Tilghman Spingler Robert Bosch GmbH Dept K2/ELS 11 Postfach 13 42 D-4710 Reutlingen Germany; Herr Tilghman Spingler Robert Bosch GmbH Dept K2/ELS 11 Postfach 13 42 D-4710 Reutlingen Germany; "FAX (49)7121-1792 Dear Herr Spingler: This responds to your FAX o July 9, 1992, asking for a 'quick answer' to your question regarding the aim of replaceable bulb headlamps. Specifically, you ask whether the requirement of 'a vertical aim range of +/-4 degrees and a horizontal aim range of +/- 2.5 degrees' means 'that a headlamp has to meet both ranges in addition, i.e. 2.5 degrees horizontal at a full range of 4 degrees vertical and vice-versa?' The requirements to which you refer are found in paragraphs S7.7.3 and S7.7.4 of Standard No. 108. Paragraph S7.7.3 requires in pertinent part that 'When a headlamp system is tested in a laboratory, the range of its vertical aim shall be not less than +/- 4 degrees from the nominal correct aim position for the intended vehicle application.' Paragraph S7.7.4 requires that 'When a headlamp system is tested in a laboratory, the range of its horizontal aim shall be not less than 2.5 degrees from the nominal correct aim position for the intended vehicle application.' We call your attention to paragraph S7.7.2.2. With respect to headlamps aimed by moving the reflector relative to the lens and headlamp housing, or vice versa, the paragraph requires conformance with respect to the applicable photometrics 'with the lens at any position relative to the reflector within the aim range limits of paragraph S7.7.3 and S7.7.4 or any combination.' This clearly indicates that when a replaceable bulb headlamp that is aimable as provided in S7.7.2.2 is adjusted to the extreme of its range, and at all positions in between, it must continue to meet all applicable photometrics. We interpret this requirement as also applying to headlamp systems of replaceable bulbs subject to S7.7.3 and S7.7.4, but aimable in a manner outside S7.7.2 (such as movement of the entire headlamp, rather than its lens or reflector). I hope that this answers your question. Please note that under recent amendments to Standard No. 108, paragraphs S7.7.2.2, S7.7.3, and S7.7.4 have been renumbered respectively S7.8.2.2, S7.8.3, and S7.8.4. Sincerely, Paul Jackson Rice Chief Counsel"; |
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ID: aiam5520OpenMr. Mark Warlick Four Winds International Corporation 791 C.R. 15 P.O. Box 1486 Elkhart, IN 46515-1486; Mr. Mark Warlick Four Winds International Corporation 791 C.R. 15 P.O. Box 1486 Elkhart IN 46515-1486; "Dear Mr. Warlick: This responds to your fax asking about the meanin of 'designated seating position' for purposes of the Federal motor vehicle safety standards. You noted that the RVIA Handbook, dated April 23, 1991, states that 'it is the NHTSA's position that, as a minimum, there must be as many designated seating positions as there are sleeping accommodations.' You asked whether this statement is still in effect, and, if so, where you can find it in the Code of Federal Regulations. You also asked what defined area makes up one sleeping position. This will confirm that it continues to be NHTSA's position that, as a minimum, there must be as many designated seating positions as there are sleeping accommodations. This position is based on the definition of 'designated seating position,' which is set forth at 49 CFR 571.3. Under that definition, the question of whether a position in a vehicle constitutes a designated seating position is dependent in part on whether the position 'is likely to be used as a seating position while the vehicle is in motion.' If a manufacturer designs a vehicle to sleep a particular number of persons, e.g., six persons, it is logical to assume that those six persons will ride in the vehicle to their sleeping destination. Therefore, there must be at least six designated seating positions in the vehicle. A more complete discussion of this issue is presented on p. 23234 of the enclosed Federal Register notice (Final rule amending the definition of 'designated seating position,' April 19, 1979). We do not have a definition of what area makes up one sleeping position. NHTSA would consider all available information to determine the number of sleeping positions in a vehicle. This would include the size of the sleeping accommodations, e.g., whether an area is large enough to accommodate more than one person, and advertising by the manufacturer and dealers. I hope this information is helpful. If you have further questions, please feel free to call Edward Glancy of my staff at (202) 366-2992. Sincerely, Philip R. Recht Acting Chief Counsel Enclosure"; |
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ID: aiam0722OpenMr. F. A. Stewart, Vice President Safety & Reliability, American Motors Corporation, 14250 Plymouth Road, Detroit, MI, 48232; Mr. F. A. Stewart Vice President Safety & Reliability American Motors Corporation 14250 Plymouth Road Detroit MI 48232; Dear Mr. Stewart: This is in reply to your letter of May 8, 1972, as to which component included in a list attached to your letter are subject to the requirements of Motor Vehicle Safety Standard No. 302, 'Flammability of Interior Materials.' A related list was left with Mr. Joseph Zemaitis by Mr. Jim Richardson on April 25, 1972, and our letter responds to this list as well. I would point out that, in line with a suggestion you make, consideration is presently being given to an amendment to the standard which could alter our response regarding some of these components.; Paragraph S4. of Standard No. 302 lists the motor vehicle component subject to the standard. The following components you list appear to be among those specifically enumerated in that paragraph and are accordingly subject to the standard: roof bow silencer (headlining), center arm rest cushion and back boards, tape used in seat assembly, (seat cushions, seat backs), and center pillar trim panels (trim panels).; Plastic roof bows to retain hardboard roof trim seem to be closel related to or a different description of headlining and if so, would also be subject to the standard. In addition, 'a roll bar pad assembly' and steering wheel pads would appear to fall within the phrase, '. . . padding . . . designed to absorb energy on contact by occupants in the event of a crash.' Stereo speaker grills and cones incorporated into a door or rear shelf would be considered part of a 'trim panel' and 'compartment shelf,' respectively.; The following components from your list would not be subject to th standard unless they are '. . .any other materials . . . designed to absorb energy on contact by occupants in the event of a crash': fresh-air deflector, instrument panel end cap, pinch welt, control knobs, transfer case shift lever gasket, dome lamp bezel and lens, 'A'. 'B', 'C', and 'D' post covers, instrument cluster lens, heater/air conditioning distribution ducts, defroster nozzle, defroster and air conditioner outlets, assist straps - door or instrument panel mounted, steering wheel rim material, and wood grain overlay adhered to gauge panel.; The following items that you list are not enumerated in S4.1, and a you state they are not energy absorbing, would not be subject to the standard: front face of instrument panel and glove box door, and cover for steering wheel rims. Finally, based on your description of both roof-silencer pads and dash pads, they would not be subject to the standard.; Yours truly, Richard B. Dyson, Assistant Chief Counsel |
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ID: aiam1830OpenMr. David E. Martin, General Motors Corporation, General Motors Technical Center, Warren, MI 48090; Mr. David E. Martin General Motors Corporation General Motors Technical Center Warren MI 48090; Dear Mr. Martin: This responds to General Motors' January 14, 1975, request fo confirmation that a Type II seat belt assembly demonstrated to Messrs. Carter, Detrick, Hofferberth, Burgett, Hitchcock, and Herlihy of the NHTSA on December 17, 1974, satisfies the requirements of S7.1.1 of Standard No. 208, *Occupant crash protection*, that the lap belt portion 'adjust by means of an emergency-locking or automatic-locking retractor.' You describe the seat belt assembly as of the single retractor, continuous loop type, with a B-pillar-mounted 'window shade' emergency-locking retractor, and a one-way frictional 'D ring' buckle tongue which limits return of webbing to the lap belt portion from the torso portion when the belt assembly is in use. At the December 17 demonstration you specifically asked if the 'D ring' frictional characteristics satisfy the criterion established in a September 25, 1972, letter to Renault, Inc. (copy enclosed), that 'the friction in the buckle is low enough that the normal motion of the occupant against the shoulder belt cinches up the lap belt.'; Section S7.1.1 requires adjustment of the lap belt portion 'by means o an emergency-locking or automatic-locking retractor' and adjustment in most cases of the upper torso portion 'by means of an emergency-locking retractor.' The language permits some single retractor, continuous loop systems as long as the single retractor does 'automatically adjust' the tension of the lap belt portion to prevent excessive belt slack. Because of the submarining danger of a slack lap belt, the NHTSA has restricted the acceptability of continuous loop systems under S7.1.1 in two areas.; One restriction was set out in the Renault letter and it is the basi for your question whether the GM 'D ring' has a sufficiently low level of friction to qualify the lap portion as 'automatically adjustable.'; We would like to clarify that letter by emphasizing that, to conform t the requirements, the assembly must be *designed* by the manufacturer with a sufficiently low level of friction to qualify the lap portion as 'automatically adjustable.' Thus it is the manufacturer who determines whether or not the particular belt is designed to satisfy the requirements of the standard. In your December 17 demonstration we saw no evidence of design deficiency in limited use of that continuous loop system.; The other restriction was set out in a March 9, 1973, letter to Genera Motors (copy enclosed). It limits the use of 'comfort clips' on the upper torso portion of continuous loop systems. The letter distinguishes continuous loop systems from systems that have separate lap and shoulder belt retractors. It concludes that 'a comfort clip would be acceptable under S7.1.1 of the standard, so long as the shoulder belt is otherwise capable of adjustment as required by S7.1.1.'; This restriction has since been the subject of an NHTSA proposa (Docket 74-32, Notice 1) which would restrict the use of 'a device used to limit retractive action of an emergency-locking retractor for the comfort of the occupant' to seat belt assemblies that have 'an individually adjustable lap belt.' General Motors' response to that proposal and its anticipated use of a 'window shade' device in future continuous loop systems assume that NHTSA intends to permit 'belt tension relief' devices on all continuous loop systems. I would like to point out that this issue is outstanding in Docket 74- 32.; Pursuant to your request for confidential treatment of this question o a new seat belt assembly, this letter will be made public only after the introduction of the new vehicle in question.; Sincerely, Robert L. Carter, Associate Administrator, Motor Vehicl Programs; |
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ID: aiam0688OpenMr. Lee S. Richards, Lee Equipment, Incorporated, 38 Old Route 6, Carmel, NY 10512; Mr. Lee S. Richards Lee Equipment Incorporated 38 Old Route 6 Carmel NY 10512; Dear Mr. Richards: This is in reply to your letter of April 11, 1972, to our New Yor office, that has been referred to me.; Paragraph 568.3 of Title 49 of the Code of Federal Regulations states ''Final stage' manufacturer means a person who performs such manufacturing operations on an incomplete vehicle that it becomes a completed vehicle.'; The subject is also dealt with in the Preamble to Part 568 '. . .Th definitions by which the regulation establishes the categories of 'incompete (sic) vehicle,' 'completed vehicle,' and the three categories of vehicle manufactures provide a framework within which each *may categorize himself* and his products. Of necessity, the definitions are broad and may not clearly define individual situations . . . . In the usual case, it will be possible for the affected manufacturers to *reach agreement between themselves* as to their respective obligations . . . .' (emphasis added); In the event that the matter is in dispute between yourself and th tank installer we would be inclined, based on the information in hand, to rule that the tank installer is the final stage manufacturer inasmuch as the equipment that you install would be 'readily attachable.'; Your obligations as a manufacturer would be the same whether the tan you install on the new chassis is new or used.; I trust this will answer your questions. Sincerely, Francis Armstrong, Director, Office of Standard Enforcement, Motor Vehicle Programs; |
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ID: aiam5170OpenMr. Cleo Betts Director of Engineering Coachmen Recreational Vehicle Co. P.O. Box 30 Middlebury, IN 46540; Mr. Cleo Betts Director of Engineering Coachmen Recreational Vehicle Co. P.O. Box 30 Middlebury IN 46540; "Dear Mr. Betts: This responds to your letter of February 22, 1993 concerning free standing furniture in motor vehicles. Specifically, you asked whether a dinette table and its chairs must be secured to the floor in a motor home. You also asked whether the chairs would be considered designated seating positions. I am pleased to have this opportunity to explain our laws and regulations to you. NHTSA is authorized under the National Traffic and Motor Vehicle Safety Act (15 U.S.C. 1381 et seq., Safety Act) to issue motor vehicle safety standards that apply to the manufacture and sale of new motor vehicles and new items of motor vehicle equipment. NHTSA has not established any safety standards which would apply to the dinette table. With respect to the dinette chairs, NHTSA has used this authority to establish Federal Motor Vehicle Safety Standard No. 207, Seating Systems (49 CFR 571.207), which specifies strength requirements for occupant seats. An 'occupant seat' is defined in S3 of Standard No. 207 as 'a seat that provides at least one designated seating position.' NHTSA has also exercised its authority under the Safety Act to establish Standard No. 208, Occupant Crash Protection (49 CFR 571.208), which specifies performance requirements for the protection of vehicle occupants in crashes. These requirements are also directed toward the occupants of 'designated seating positions.' The term 'designated seating position' is defined at 49 CFR 571.3 as: any plan view location capable of accommodating a person at least as large as a 5th percentile adult female, if the overall seat configuration and design is such that the position is likely to be used as a seating position while the vehicle is in motion, except for auxiliary seating accommodations such as temporary or folding jump seats. Attached dinette seats in motor homes are 'designated seating positions' under this definition and are therefore required to comply with the requirements of Standard No. 207. In addition, Standard No. 208 requires these seats to be equipped with seat belts. The type of seat belt required varies depending on the seating capacity and gross vehicle weight rating of the vehicle. Your letter raises the question of whether seats that are not attached to the vehicle would be considered 'auxiliary seating accommodations' and therefore not 'designated seating positions.' It is our opinion that attachment is not determinative. A manufacturer cannot escape the responsibilities of Standards Nos. 207 and 208 simply by not attaching the seat. We would look at all relevant factors in determining whether a particular seat is an auxiliary seating accommodation such as temporary or folding jump seat. I also note that S.4.4 of Standard No. 207 requires that seats not designated for occupancy while the vehicle is in motion shall be conspicuously labeled to that effect. I must emphasize, however, that the concept of free standing furniture in motor vehicles raises a potentially serious safety concern. Unattached items, including but not limited to furniture, could be very dangerous to vehicle occupants if these items are free to move inside the occupant compartment during sudden stops or in a crash. Manufacturers of motor vehicles are subject to the defect provisions of the Safety Act. If a vehicle manufacturer included unattached items that exposed occupants to an unreasonable risk of injury, it could constitute a safety related defect that could require the manufacturer to conduct a safety recall. I have enclosed an information sheet that identifies relevant Federal statutes and NHTSA standards and regulations affecting motor vehicle and motor vehicle equipment manufacturers, and explains how to obtain copies of these materials. 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: aiam0372OpenMr. Ray Thoman, President, 707 Tire Service, Inc., 5901 Courtesy Lane, Shreveport, LA (sic); Mr. Ray Thoman President 707 Tire Service Inc. 5901 Courtesy Lane Shreveport LA (sic); Dear Mr. Thoman: This is in reply to your letter of June 15, 1971, concerning the Tir Identification and Record Keeping Regulation (49 CFR Part 574).; As stated in the interpretation published in the *Federal Register* o May 28, 1971, under section 113(f) of the National Traffic and Motor Vehicle Safety Act, 'it is the tire manufacturer who has ultimate responsibility for maintaining the records of first purchasers'.; Under the Act and the Regulation, we have no authority to require tire manufacturer to choose someone as his designee. I have asked Goodyear's counsel for their position with regard to the possible use of tire dealers customer's lists and was forwarded a letter dated June 8, 1971, from the Goodyear Tire and Rubber Company which sets forth the company's policy with regard to the prohibition in the regulation. I enclose the letter for your information.; Sincerely, Lawrence R. Schneider, Acting Chief Counsel |
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ID: aiam4331OpenMr. Nobuyoshi Takechi, Technical Manager, MMC Services Inc., 3000 Town Center, Suite 1960, Southfield, MI 48075; Mr. Nobuyoshi Takechi Technical Manager MMC Services Inc. 3000 Town Center Suite 1960 Southfield MI 48075; Dear Mr. Takechi: This is in reply to your letter of April 24, 1987, with reference t the legality of a proposed concealed headlamp design.; As we understand the proposed design, the headlamp could be used in th 'concealed' position as a forward warning (which you believe 'is similar to the daytime running light principle' and 'is useful to avoid accidents') and in the unconcealed position as a headlamp to provide visibility of the roadway ahead. A portion of the vehicle body in front of the concealed headlamp would be clear, allowing the beam from the concealed lamp to shine through it. The steady burning forward warning signal would be given by pulling a spring-loaded switch. Releasing the switch would turn off the headlamp. Thus, the concealed headlamp would not, as a practical matter, be used for providing visibility of the roadway ahead but as an alternative to the vehicle's audible warning device, the horn. The proposed use would be a visual 'horn.' Finally, you state that the beam pattern and intensity of the lamp 'is corresponding to the headlamp's,' although you do not explain how this is possible, given the potential for interference from the vehicle's body.; Standard No.108 prohibits covers or other styling features in front o a required headlamp when it is being used for purposes such as illuminating the roadway ahead or increasing the visibility of the vehicle in conditions of reduced visibility. We do not consider this prohibition applicable when a headlamp is being used, in all likelihood momentarily, for forward signalling as described. Further, use in this manner would not appear to impair the lighting equipment required by the standard. Additionally, headlamps may be wired to flash for signalling purposes, as you have proposed, however, we are unable to advise you whether operation of this device is acceptable under the laws of the individual States. Your letter does not indicate whether the beam utilized is the upper beam or the lower beam, some jurisdictions such as the District of Columbia and Virginia prohibit use of the upper beam for signaling purposes. Others may restrict use of headlamps or a portion of them during daylight hours, we expect to learn more about this in comments to the docket on the daytime running lamp proposal. In the meantime, I would advise you to write the American Association of Motor Vehicle Administrators, 1201 connecticut Avenue, NW, Washington, DC 20036, for its views on State laws.; You have stated that this use 'is similar to the daytime running ligh principle.' However, as proposed by the Government of Canada, and by the U.S. Government in the Federal Register (52 FR 9316) such 'DRLs' would be automatically energized, and not energized at the driver's choice as is your device. Therefore, we do not view the operation of your device as similar to the daytime running light principle.; Sincerely, Erika Z. Jones, Chief Counsel |
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ID: aiam1133OpenMr. John L. Wilson, Jr., President, Help of Nebraska, Inc., 4601 South 90th Street, Suite No. 2, Omaha, NE 68127; Mr. John L. Wilson Jr. President Help of Nebraska Inc. 4601 South 90th Street Suite No. 2 Omaha NE 68127; Dear Mr. Wilson: This is in reply to your letter of April 30, 1973, in which you as whether an 'infant car hammock' which you manufacture is required to conform to Motor Vehicle Safety Standard No. 213. A picture of the hammock, which you enclosed, shows the hammock attached to both rear doors of a vehicle, and extending between them, with a child lying on it.; As pictured, the hammock is not subject to Standard No. 213. Th standard applies, at present, to devices for seating and restraining a child being transported in a motor vehicle. Effective November 1, 1973, it will apply to all devices for seating a child being transported in a motor vehicle, irrespective of whether the device is used for restraint. Because the hammock is not designed to seat a child, it is not subject to the standard. A copy of the standard is enclosed.; We are presently developing proposed amendments to the standard tha would apply to all types of infant and child restraints, including devices in which children do not sit. These proposals will be published in the *Federal Register* when completed.; We are enclosing a copy of our consumer information booklet, 'What t Buy in Child Restraint Systems'. Our recommendations for infant carriers and car beds are found at the center pages of the booklet.; We hope the information we have provided answers your questions and w appreciate your concern for child restraint safety.; Sincerely yours, Robert L. Carter, Associate Administrator, Moto Vehicle Programs; |
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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.