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: aiam2654OpenHonorable Lamar Gudger, House of Representatives, Washington, DC 20515; Honorable Lamar Gudger House of Representatives Washington DC 20515; Dear Mr. Gudger: Please excuse the delay in my response to your letter of June 15, 1977 addressed to Mr. Norman Sultan, with a copy to the National Highway Traffic Safety Administration (NHTSA) regarding the Federal requirement for registration of tires.; Mr. Sultan has reported a tire registration of 10 percent in his are of operation which is considerably less than the national figures of 30 percent for retreads and 70 percent for new tire replacements developed in our studies. Mr. Sultan is urging a change in the law to permit voluntary registration of all tires.; Mr. John Snow, my predecessor, reported to the Honorable Warren G Magnuson, Chairman of the Committee on Commerce, U.S. Senate, that consideration would be given to changing Regulation Part 574 allowing voluntary registration of retreaded tires in lieu of mandatory registration. Since taking office, I have devoted considerable attention to reviewing and analyzing the pertinent factors related to tire registration. I am convinced of the safety benefits of registering new tires and I consider the mandatory recordkeeping provision essential to the purpose of the Vehicle Safety Act. However, because retreaded tires are individually manufactured and therefore could not be recalled as are mass produced items, I am considering proposing revocation of the mandatory recordkeeping requirement for retreaded tires.; For your information I am enclosing a copy of my recent letter t Senator Magnuson in response to his questions on this subject.; You may be interested to know that a recent meeting wit representatives of the National Tire Dealers and Retreaders Association (NTDRA) provided an opportunity to discuss basic clerical problems associated with registration. As a result, an interpretation of the regulation was reached which would permit the tire purchaser personally to complete the registration form. Although dealer responsibility remains, the interpretation is considered by NTDRA to provide considerable relief to dealers in time and cost. Hopefully this action will offset much of the objections to the current tire registration process.; Sincerely, Joan Claybrook |
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ID: aiam0669OpenMr. Louis C. Lundstrom, Director, Automotive Safety Engineering, General Motors Environmental Activities Staff, General Motors Technical Center, Warren, MI, 48090; Mr. Louis C. Lundstrom Director Automotive Safety Engineering General Motors Environmental Activities Staff General Motors Technical Center Warren MI 48090; Dear Mr. Lundstrom: This is in reply to your letter of March 28, 1972, in which you as whether, for purposes of Motor Vehicle Safety Standard No. 302, 'Flammability of Interior Materials,' you may consider the 'occupant compartment' for van and panel-type trucks to be 'the front area of the vehicle extending rearward to the rearmost point on any occupant seat.'; We would consider a reasonable interpretation of the phrase 'occupan compartment,' when applied to van and panel-type trucks which have no physical barrier between the occupant and cargo compartments, to be that area forward of a vertical plane perpendicular to the longitudinal centerline of the vehicle, and tangent to the rearmost point of any occupant seat in its rearmost position. This interpretation appears to be substantially the same as that expressed in your letter.; We are pleased to be of assistance. Yours truly, Richard B. Dyson, Assistant Chief Counsel |
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ID: aiam5191OpenMr. Lanny Kness Coach Design Engineer Chance Coach, Inc. 4219 Irving, Box 12328 Wichita, KS 67277-2328; Mr. Lanny Kness Coach Design Engineer Chance Coach Inc. 4219 Irving Box 12328 Wichita KS 67277-2328; "Dear Mr. Kness: This responds to your request for an interpretation o two sections of Federal Motor Vehicle Safety Standard (FMVSS) No. 101, Controls and displays (49 CFR 571.101). You ask whether S5.1 requires a turn signal control to be hand operated. As explained below, the answer is no. You also ask whether S5.3's illumination requirements can be met by two different means: reflected light, and an overhead light. The answer is no. By way of background information, the National Highway Traffic Safety Administration (NHTSA) does not provide approvals of motor vehicles or motor vehicle equipment. Under the National Traffic and Motor Vehicle Safety Act, it is the responsibility of the manufacturer to ensure that its motor vehicles or equipment comply with applicable safety standards. The following represents our opinion based on the facts provided in your letter. Your first question asks whether S5.1 requires a turn signal control to be hand operated. S5.1 specifies location requirements for each control listed in S5.1 'that is furnished.' S5.1 does not require manufacturers to furnish any control, such as a hand-operated turn signal control, or prohibit manufacturers from providing an unlisted control, such as a foot-operated turn signal control. While FMVSS No. 108, Lamps, reflective devices, and associated equipment (49 CFR 571.108) specifies the 'turn signal operating unit' as required equipment, it does not specify that the unit be hand operated. (See S5.1.1 and Table I of FMVSS No. 108.) Your second question asks whether the following proposed method of illuminating the windshield wiper/washer control complies with S5.3.3 of Standard No. 101. You state that the wiper/washer control is located on the dashboard and at night, the 'control knob's identification' can be barely seen from indirect lighting coming from other controls and displays. The wiper washer control would become 'very discernible' by turning on an 'overhead driver's controlled light.' For the following reasons, the above described method of illuminating the wiper/washer control would not comply with Standard No. 101. S5.3.3(a) requires means to be provided to make controls visible to the driver under all driving conditions. S5.3.3(b) states that 'the means' (emphasis added) for providing the required visibility: (1) Shall be adjustable, except as provided in S5.3.3(d), to provide at least two levels of brightness, one of which is barely discernible to a driver who has adapted to dark ambient roadway conditions. S5.3.3(b) therefore requires that a single control (i.e., 'the means') be adjustable to provide at least two levels of brightness. Under your proposal, however, two different means must be used to provide two levels of brightness. The overhead driver's light would provide one level of brightness, that makes the control 'very discernible.' The other level of brightness (one barely discernible to the driver) is provided from reflected light given off by other controls and displays located on the dashboard. Since no single 'means' that you propose for illumination would be adjustable to provide at least two levels of brightness, your proposal would not comply with S5.3.3 of Standard No. 101. I hope that this information is useful. If you have any further questions, please contact Dorothy Nakama of my staff at (202) 366-2992. Sincerely, John Womack Acting Chief Counsel"; |
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ID: aiam0147OpenMr. Eugene D. Prahst, Chief Product Engineer, Dump Trailer Division, The Heil Company, 3000 W. Montana Street, Milwaukee, WI 53201; Mr. Eugene D. Prahst Chief Product Engineer Dump Trailer Division The Heil Company 3000 W. Montana Street Milwaukee WI 53201; Dear Mr. Prahst: Thank you for your letter of February 24, 1969, to the Office o Standards Preparation, concerning the proposed lighting equipment on your dump trailers.; The lamps and reflectors shown on your drawing 701B1907 dated Februar 20, 1969, appear to be in conformance with the requirements of Standard No. 108 with the following exceptions:; >>>1. The required license plate lamp is not shown. 2. The minimum mounting height for reflectors is 15 inches. 3. With respect to maximum mounting zones for lamps and reflectors, th limiting dimensions of 16, 30, and 24 inches indicated on your drawing appear to be too liberal for a trailer with essentially square corners.; 4. With reference to Notes 2 and 3 on your drawing, certai restrictions as specified in paragraph S3.3 of Standard No. 108 are applicable for combination lamps.<<<; With respect to the requirements of Standard No. 108, I must point ou that this Bureau does not issue approvals on items of lighting equipment or on vehicle designs incorporating this equipment. Therefore, the above comments are for your information only, and in no way relieve the vehicle manufacturer from his responsibility for certifying that the assembled vehicle meets the requirements of Standard No. 108.; Sincerely, Charles A. Baker, Office of Standards on Accident Avoidance Motor Vehicle Safety Performance Service; |
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ID: aiam5345OpenMr. Gary Klingaman Engineer Inter Pipe, Inc. 3807 W. Adams Phoenix, AZ 85009-4764; Mr. Gary Klingaman Engineer Inter Pipe Inc. 3807 W. Adams Phoenix AZ 85009-4764; "Dear Mr. Klingaman: This responds to your March 16, 1994, lette inquiring about the applicability of National Highway Traffic Safety Administration (NHTSA) regulations to the alteration of used motor vehicles. You stated that your company manufactures water trucks and lube/fuel service trucks by adding water tanks and various other apparatus to incomplete vehicles. Your question is whether you are required to add a certification label (as required in 49 C.F.R. 571.115) even if you use a 'pre-owned' (I assume you mean 'used') truck chassis. Some background information on Federal motor vehicle safety laws and regulations may be helpful. As you are aware, our agency is authorized under the National Traffic and Motor Vehicle Safety Act (15 U.S.C. 1381 et seq., Safety Act), to issue safety standards applicable to new motor vehicles and certain items of motor vehicle equipment. NHTSA however does not approve motor vehicles or motor vehicle equipment, nor do we endorse any commercial products. Instead, the Safety Act establishes a 'self-certification' process under which each manufacturer is responsible for certifying that its products meet all applicable safety standards. Whether Inter Pipe, Inc. would have to apply a certification label depends upon whether the vehicles your company modifies are new (that is, the vehicles have not yet been sold to the first retail purchaser) or used (vehicles that have already been sold to and used by the first retail purchaser). With respect to your company's modifications of new vehicles, your company would be a 'final stage manufacturer' for the purposes of NHTSA's laws and regulations. 49 C.F.R. 568.6 requires a final stage manufacturer of a new vehicle to affix a certification label in accordance with 49 C.F.R. 567.5. The requirements of 49 C.F.R. Parts 567-568 do not apply if you modify used vehicles. Hence, your company is not required to affix a manufacturer's label to those used vehicles you convert into water trucks or fuel/lube trucks. However, 108(a)(2)(A) of the Safety Act provides that no manufacturer, distributor, dealer, or motor vehicle repair business may knowingly 'render inoperative,' in whole or in part, any device or element of design installed on or in a motor vehicle or item of motor vehicle equipment in compliance with an applicable Federal motor vehicle safety standard. Therefore, you must be careful when adding your equipment not to degrade the truck's ability to meet the safety standards. For your information, I have enclosed a general information sheet for manufacturers that gives a thumbnail sketch of the relevant NHTSA regulations and explains how to get copies of those regulations. I hope this information is helpful. If you have any further questions or need some additional information on this subject, feel free to contact our office at (202) 366-2992. Sincerely, John Womack Acting Chief Counsel Enclosures"; |
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ID: aiam2480OpenMr. Trevor O. Jones, Chairman, Truck & Bus Safety Subcommittees, Department of Transportation, Washington, DC 20590; Mr. Trevor O. Jones Chairman Truck & Bus Safety Subcommittees Department of Transportation Washington DC 20590; Dear Mr. Jones: This responds to your September 1, 1977, request for clarification o the legal issues that face truck manufacturers who, at the request of owners, replace brake components used in satisfaction of the early performance levels of Standard No. 121, *Air Brake Systems*, with brake components that are used in satisfaction of the existing reduced performance levels of the standard. Your concern is that some manufacturers may be reluctant to undertake such replacement if it involves testing and recertification of the vehicle to Standard No. 121.; The National Traffic and Motor Vehicle Safety Act (the Act) (15 U.S.C S 1381 et seq.) prohibits the manufacture, offer for sale, sale, introduction in interstate commerce or importation of a motor vehicle that does not comply with all applicable standards in effect on the date of its manufacture (S 108(a)(1)(A)). This prohibition does not apply (except for importation) after the first purchase of the vehicle in good faith for purposes other than resale (15 U.S.C. S 108(b)(1)). Section 114 of the Act requires that the manufacturer certify compliance of a vehicle to applicable standards at the time of delivery to the distributor or dealer. There is no basis under these or any other statutory provisions for the manufacturers' belief that recertification of a used vehicle is required, however it may be modified.; The manufacturers you mention may be concerned about their liabilit under S 108(a)(2)(A) which prohibits, except in the process of repair, a manufacturer, distributor, dealer, or repair business from knowingly rendering inoperative in whole or part, any device or element of design installed in a motor vehicle in compliance with an applicable standard. As you know, it is the published opinion of the National Highway Traffic Safety Administration that a commercial facility does not 'knowingly render inoperative' a device or element of design by replacing components installed in satisfaction of a safety standard with other components that are used in newer vehicles of the same type in satisfaction of the same standard, even if the standard for the newer vehicles impose a less stringent level of performance (42 FR 26279, May 23, 1977). The manufacturers may believe that they have a statutory obligation to prove that the substituted parts, as installed in each vehicle, in fact provide performance equal to that required by the existing standard.; It is, of course, a factual matter in each case whether the modifie used vehicle does in fact provide the performance for new vehicles specified by Standard No. 121. I would like to point out, however, that (1) the Act requires certification of vehicles only upon initial delivery to the distributor or dealer, (2) the normal deterioration of brake components on vehicles-in-use would make it virtually impossible to determine as a factual matter whether the substitution of smaller, new components in fact degrade performance of the vehicle, and (3) the prohibition of S 108(a)(2)(A) requires intent to degrade the system on the part of the manufacturer before the modification would constitute a violation.; In view of these factors, I am surprised that manufacturers believ they need to conduct road testing to ensure they do not violate S 108(a)(2)(A). My understanding is that truck models do not change radically from year-to-year, and that the certification testing following Notice 7 was conducted on vehicles similar to those built in the January 1975 to March 1976 period. I would expect that the results of those tests could be used as a basis for deciding whether the modified vehicles provide the specified level of performance.; Sincerely, Joan Claybrook |
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ID: aiam0517OpenMr. John C. Latzer, Plant Manager, Mobilefreeze Co., Inc., P. O. Box 691, Parsons, KS, 67357; Mr. John C. Latzer Plant Manager Mobilefreeze Co. Inc. P. O. Box 691 Parsons KS 67357; Dear Mr. Latzer: This is in reply to your letter of September 7, 1971, to Mr. Sta Haransky, Truck Body and Equipment Association, Inc., concerning the mounting height of lamps and reflectors on your motorcycle trailers.; A copy of Federal Motor Vehicle Safety Standard No. 108, 'Lamps Reflective Devices and Associated Equipment' is enclosed for your information. The minimum mounting height for lamps and reflectors listed in Table IV of this Standard is 15 inches. We do not have the authority to exempt any motor vehicles from meeting these requirements.; Sincerely, E. T. Driver, Director, Office of Operating Systems, Moto Vehicle Programs; |
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ID: aiam4807OpenMr. Gordon Bonvallet 1686 Lighthouse Hill Road Homer, NY 13077; Mr. Gordon Bonvallet 1686 Lighthouse Hill Road Homer NY 13077; Dear Mr. Bonvallet: This is in reply to your letter of October 5, l990 with respect to a prospective headlighting system. It is contemplated that the lower beam on the system would be furnished by a gaseous discharge headlamp, an 'integral beam' headlamp under Standard No. 108. The upper beam would be furnished by a replaceable bulb headlamp using an HB3 light source. You comment that a combination system such as this is not specifically addressed by Standard No. 108, and you ask for confirmation of your opinion that the photometric requirements of Figure l5 would apply to both the upper and lower beam headlamps. At the present time, such a hybrid headlighting system is impermissible under Standard No. 108. The standard establishes separate requirements for integral beam headlighting systems (S7.4), and for replaceable bulb headlighting systems (S7.5). Though 'integral beam headlighting system' is not specifically defined by Standard No. 108, such a system would appear to be one that consists of integral beam headlamps. Standard No. 108 does define 'integral beam headlamp', and that definition specifically excludes 'a replaceable bulb headlamp' such as one containing an HB3 light source. Similarly, a 'replaceable bulb headlamp system' is one that consists solely of headlamps containing HB1, HB2, HB3, HB4, or HB5 light sources. It is true that Figure l5 is one of three lower beam photometric options that apply to an integral beam headlamp, such as one producing illumination through gaseous discharge. However, under the language of the standard, Figure l5 applies when the lamp is used in a four headlamp integral beam headlighting system (S7.4(a)(l)(i)). It is also true that the upper beam photometrics of Figure 15 apply to an HB3 replaceable bulb headlamp (S7.5(e)(3)(ii)), but only when used in a four lamp headlighting system in which each headlamp contains a single replaceable light source. As you know, the policy of this agency for the last decade has been to reduce design restrictions on headlighting systems. Removal of the implicit prohibition against hybrid headlighting systems would be a further step in this direction. If your client is seriously considering such a system, it may submit a petition for rulemaking at the appropriate time. Sincerely, Paul Jackson Rice Chief Counsel; |
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ID: aiam1756OpenMr. Michael Schenker,President,Coilhose Pneumatics,415 Hope Avenue,Rosell, New Jersey 07203; Mr. Michael Schenker President Coilhose Pneumatics 415 Hope Avenue Rosell New Jersey 07203; Dear Mr. Schenker:#Please forgive the delay in responding to you letter of November 15, 1974. I have enclosed a copy of Federal Motor Vehicle Safety Standard No. 106-74, *Brake Hoses*, a copy of the most recent amendment to the standard (39 FR 39725), and an information sheet entitled 'Where to Obtain Motor Vehicle Safety Standards and Regulations'. #The system of staggered effective dates is as follows: All brake hose and brake hose end fittings manufactured after September 1, 1974, must conform to the standard. All brake hose assemblies manufactured after March 1, 1975, must conform to the standard. All vehicles manufactured after September 1, 1975, must contain only hose and assemblies which conform to the standard.#As a manufacturer of air brake hose assemblies, you must label each assembly manufacturer on or after March 1, 1975, with a band as described in S7.2 and S5.2.4. Use of the band before March 1, 1975, is not permitted. Assemblies manufactured after this date must consist of hose and end fittings which also conform to the standard. During the period from March 1, 1975 to August 31, 1975, however, S12 (added by the recent amendment) permits the construction of assemblies with hoes and end fittings which are not labeled according to the standard, as long as they meet all the performance requirements. These assemblies must nevertheless be labeled with a band.#Please note also that assemblies manufactured before March 1, 1975, (i.e.., those without bands) may not be installed in new vehicles manufactured on or after September 1, 1975. If you have any questions about these requirements, feel free to contact Mark Schwimmer of this office.#Yours truly,Richard B. Dyson,Acting Chief Counsel; |
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ID: aiam0844OpenMr. Robert J. Webster, Executive Vice President, Denman Rubber Manufacturing Company, Warren, Ohio 44482; Mr. Robert J. Webster Executive Vice President Denman Rubber Manufacturing Company Warren Ohio 44482; Dear Mr. Webster: This is in reply to your letter of August 14, 1972, requestin information as to whether you may sell tires to a Mr. Harvey Livingston, who is in the business of repairing tires with correctable defects. You ask what assurances you should obtain that the tires are actually repaired and rebranded by Mr.Livingston before their sale by him.; The sale of passenger car tires is subject to the National Traffic an Motor Vehicle Safety Act (15 U.S.C. 1381 *et seq*.) and Motor Vehicle Safety Standard No. 109, 'New Pneumatic Tires' (49 CFR 571.109). Under these provisions tire manufacturers may sell passenger car tires only in the following circumstances: They may sell tires which conform to the performance and labeling requirements of Standard and the Tire Identification and Recordkeeping regulations (49 CFR Part 574), or, they may sell until October 1, 1972, (See our notice of August17, 1972, 37 F.R. 16604) tires which have been reclassified pursuant to paragraph S6 of Standard No. 109. This requires the removal of original labeling and the affixing of new labels which warn against the use of such tires in public highways. These restrictions apply to the sale of passenger car tires to any purchasers including persons such as Mr. Livingston, who wish to repair the tires and resell them.; If you sell *conforming* tires to Mr. Livingston, he would not b required by Federal regulations to remove Denman labeling and to affix his own. Whether or not he did this would depend upon whatever agreement you reach with him. A satisfactory assurance, should you agree with him to follow this procedure, would be a written agreement to that effect, but you should also record the serial numbers of tires which you sell to him. Denman, however, is not permitted to remove its own labeling before sale.; Even if Mr. Livingston affixes the DOT symbol and his ow identification number to the tires, the NHTSA would not necessarily find him responsible should the tire fail to conform to Standard No. 109. Mr. Livingston would be entitled to show that the reason for the nonconformity is not attributable to the work he performed. If he could demonstrate this,Denman could then be found responsible for the nonconformity.; If you sell Mr. Livingston 'reclassified tires', Mr. Livingston woul be required to label the tires as required by Standard No. 109, and to certify their conformity to the Standard before he could sell them as passenger car tires. In this situation, Mr. Livingston would be responsible if the tires failed to conform to Standard No. 109.; We have sent Mr. Livingston a copy of our response. Yours truly, Richard B. Dyson, Assistant 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.