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: aiam3521OpenMr. L. J. A. Mills, G. & C. Mills Plastics Inc., 9 Carrier Drive, Ontario, Canada M9V4B2; Mr. L. J. A. Mills G. & C. Mills Plastics Inc. 9 Carrier Drive Ontario Canada M9V4B2; Dear Mr. Mills: This responds to your recent letter asking whether an auxiliary win deflector which you sell must have a 'safety label.' Also, you ask whether you should send one of your products to the agency in order to obtain official approval.; The answer to your first question is yes. Section 108(a)(1) of th National Traffic and Motor Vehicle Safety Act provides that no person shall; >>>'(A) manufacture for sale, sell, offer for sale, or introduce o deliver for introduction in interstate commerce, or import into the United States, any motor vehicle or item of motor vehicle equipment manufactured on or after the date any applicable Federal motor vehicle safety standard takes effect under this title unless it is in conformity with such standard . . .; '(C) fail to issue a certificate required by section 114, or issue certification to the effect that a motor vehicle or item of motor vehicle equipment conforms to all applicable Federal motor vehicle safety standards, if such person in the exercise of due care has reason to know that such certification is false or misleading in a material respect.'<<<; Since your auxiliary wind deflector is a piece of motor vehicl equipment and is subject to Safety Standard No. 205, *Glazing Materials*, you are required by section 108 to certify that it complies with that standard. As noted on page 2 of our October 8, 1980 letter to Mr. Hingtgen (which you received), section 114 of the Vehicle Safety Act requires the manufacturer or distributor to place a label or tag on the item of equipment or on the outside container in which the equipment is delivered. This label or tag must state (i.e., certify) that the item of equipment complies with all applicable safety standards, in this case Standard No. 205. You are correct in your assumption that you print this label or tag yourself. The agency does not provide the labels.; In answer to your second question, you should not send a sample of you product to the agency for approval. The agency does not grant prior approval of any motor vehicle or piece of motor vehicle equipment. As you can see from section 108 quoted above, the Vehicle Safety Act requires self- certification by the manufacturer that its product is in compliance with all applicable Federal motor vehicle safety standards. The agency's enforcement program begins only after the manufacturer has certified its product (i.e., the agency may obtain an item of equipment or vehicle from the open market and determine whether it is in fact in compliance with all standards).; I hope this has answered all remaining questions you might have. Sincerely, Frank Berndt, Chief Counsel |
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ID: aiam0024OpenMr. John Hollyfield, Inspector, Motor Vehicle Inspection, Texas Department of Public Safety, 5205 N. Lamar Boulevard, Box 4067, North Austin Station, Austin, TX, 78751; Mr. John Hollyfield Inspector Motor Vehicle Inspection Texas Department of Public Safety 5205 N. Lamar Boulevard Box 4067 North Austin Station Austin TX 78751; Dear Mr. Hollyfield: Mr. Arnold Wise has asked that I answer your letter of April 14, 1967 concerning a clarification of several requirements of Motor Vehicle Safety Standards 207, 208, and 209.; I am enclosing copies of the *Federal Register* of August 31, 1966, an February 3, 1967, which provide all of the information which you require. You will note that Standard No. 207 is concerned with the anchorage of the seats - not seat belts. Standard No. 208 requires seat belts in all passenger cars manufactured after January 1, 1968. In a regular size, four door, sedan-type vehicle with regular undivided seats, six lap belts would be required and, in addition, upper torso restraints would be required in the front outboard seats if the windshield header is in the head impact area.; The installation of seat belts in other than passenger cars is no required by the initial standards. However, any seat belts that are manufactured after March 1, 1967, must conform to the requirements of Motor Vehicle Safety Standard No. 209.; Your interest in the traffic safety program of this Bureau i appreciated.; Sincerely, George C. Nield, Acting Director, Motor Vehicle Safet Performance Service; |
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ID: aiam2019OpenMr. Wade H. Barrineau, III, Compact Van Equipment Co., Inc., 5159 E. Shore Drive, Conyers, GA, 30207; Mr. Wade H. Barrineau III Compact Van Equipment Co. Inc. 5159 E. Shore Drive Conyers GA 30207; Dear Mr. Barrineau: This is in response to your letter of July 17, 1975, inquiring as t the regulations to which you may be subject by manufacturing and selling interior shelving, interior safety bulkheads, and roof mounted ladder carriers for Ford Econoline vans.; The National Highway Traffic Safety Administration has issue regulations covering the alteration of completed, certified motor vehicles before their sale to a purchaser for purposes other than resale. (49 CFR SS567.7 and 567.8, copy enclosed). Under these regulations, an alteration which either (1) invalidates a vehicle's existing weight ratings or (2) involves installation of other than 'readily attachable' components gives rise to a responsibility for affixing an alterer label, which identifies the alterer and contains some additional information.; From the description of your products, it appears that no specia expertise or tools are required for their installation. They would also seemingly not affect a vehicle's weight ratings. If this assessment is correct, we would accept as reasonable a manufacturer's determination that they are 'readily attachable', and that an alterer label is therefore not required when these products are installed.; The only Safety Standard that might apply to your products is Standar No. 302, *Flammability of Interior Materials* (copy enclosed).; In addition, as items of motor vehicle equipment, your products ar subject to the requirements of the National Motor Vehicle and Traffic Safety Act of 1966, as amended, and must therefore be free from safety-related defects.; If you have any further questions, feel free to write again. Sincerely, Frank A. Berndt, Acting Chief Counsel |
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ID: aiam5226OpenKenneth G. Koop, Risk Control Representative Intergovernmental Risk Management Agency One Oakbrook Terrace 22nd Street at Butterfield Road Suite 412 Oakbrook Terrace, IL 60181; Kenneth G. Koop Risk Control Representative Intergovernmental Risk Management Agency One Oakbrook Terrace 22nd Street at Butterfield Road Suite 412 Oakbrook Terrace IL 60181; "Dear Mr. Koop: This responds to your letter of June 3, 1993 requesting information on a modification for police vehicles. You seek permission to remove the passenger seat and passenger air bag from police vehicles, and to permanently mount equipment where the passenger seat had been. As explained below, this type of modification would be permitted under Federal law. By way of background information, the National Highway Traffic Safety Administration (NHTSA) is authorized under the National Traffic and Motor Vehicle Safety Act (15 U.S.C. 1381 et seq., Safety Act) to issue Federal motor vehicle safety standards that apply to the manufacture and sale of new motor vehicles and new items of motor vehicle equipment. Section 108(a)(1)(A) of the Safety Act (15 U.S.C. 1397(a)(1)(A)) prohibits any person from manufacturing, introducing into commerce, selling, or importing any new motor vehicle or item of motor vehicle equipment unless the vehicle or equipment item is in conformity with all applicable safety standards. Among the standards that NHTSA has issued are two which could be affected by the modification you propose: Standard No. 207, Seating Systems, (49 CFR 571.207), which requires each vehicle to have an occupant seat for the driver and sets strength and other performance requirements for all occupant seats in a vehicle, and Standard No. 208, Occupant Crash Protection (49 CFR 571.208), which specifies occupant protection requirements based on vehicle type and seating position within the vehicle. If your contemplated modification is made before a vehicle's first purchase for purposes other than resale, the person who modifies the vehicle would be an alterer of a previously certified motor vehicle and would be required to certify that, as altered, the vehicle continues to comply with all of the safety standards affected by the alteration (See 49 CFR Part 567.7). Once the front passenger seat is removed, Standard No. 208 would not require an air bag for that location since an occupant restraint is only required if a seating position is there. After a vehicle's first purchase for purposes other than resale, i.e., the first retail sale of the vehicle, the presence and condition of devices or elements of design installed in the vehicle under applicable safety standards is affected by section 108(a)(2)(A) of the Safety Act (15 U.S.C. 1397(a)(2)(A)). That section provides: No manufacturer, distributor, dealer, or motor vehicle repair business shall knowingly render inoperative, in whole or in part, any device or element of design installed on or in a motor vehicle ... in compliance with an applicable Federal motor vehicle safety standard. NHTSA does not consider there to be a violation of the 'render inoperative' prohibition with respect to occupant restraints if, after one of the named types of commercial entities modifies a used vehicle, the vehicle is equipped with occupant restraints at every seating position and those occupant restraints are the type that Standard No. 208 permitted when the vehicle was new. Again, if a seating position were removed from a used vehicle, the removal of the air bag as well would not violate the render inoperative provision because the presence of the air bag was originally premised on the presence of the seating position. However, the render inoperative prohibition would be violated if removal of the passenger side air bag caused the driver side air bag to malfunction or deploy. I would like to caution you to contact the vehicle manufacturer concerning the proper procedure for any air bag removal. Removing an air bag could cause it to deploy and injure the mechanic. In addition, removal of the passenger side air bag could cause the driver side air bag to malfunction or deploy. You should also note that the 'render inoperative' prohibition applies only to the named entities. Therefore, vehicle owners are permitted to make any modifications to their vehicles, even if the vehicle would no longer comply with applicable safety standards. However, we encourage vehicle owners not to tamper with the occupant protection systems installed in their vehicles. You should be aware that S4.5.2 of Standard No. 208 requires a readiness indicator for an air bag system which is clearly visible from the driver's seating position. NHTSA believes that most manufacturers install one indicator for both air bags. After the passenger side air bag is removed, this indicator would show that the air bag system is not operative. NHTSA is concerned that the driver would then be unable to tell if the driver side air bag were functional. Therefore, I urge you to contact the manufacturer to determine how the indicator could be altered to monitor the readiness of the driver side air bag only. As a final caution, I note that the purpose of the 'render inoperative' provision is to ensure, to the degree possible, current and subsequent owners and users of the vehicle are not deprived of the maximum protection afforded by the vehicle as newly manufactured. Your letter states that you will 'place permanently mounted policing equipment in the seat's place.' It is our understanding that it is common for police cars to be sold after a few years of service. Presumably any police equipment would be removed before such a sale. I urge you to either reinstall the passenger seat and occupant restraint or to make these modifications in a way that will discourage reinstallation of the passenger seat, so that future users of the vehicle are unlikely to use a seating position that does not have any occupant restraint. 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: aiam0474OpenMr. H. A. Sage, Director of Research and Engineering, Truck- Lite Company, P. O. Box 387, Jamestown, NY, 14701; Mr. H. A. Sage Director of Research and Engineering Truck- Lite Company P. O. Box 387 Jamestown NY 14701; Dear Mr. Sage: This is in reply to your letter of October 15, 1971, to Mr. Lewis Owe of this Office concerning the coating of Lexan lenses.; Plastic lenses used in the required lamps are required by Federal Moto Vehicle Safety Standard No. 108 to meet SAE J576, which specifies no loss of surface luster and no surface deterioration. This Agency does not have the authority to 'waive' any requirements of a Federal motor vehicle safety standard.; If you believe that motor vehicle safety does not demand requirement of this severity, you may submit a petition asking for an appropriate amendment of Standard No. 108.; Sincerely, E. T. Driver, Director, Office of Operating Systems, Moto Vehicle Programs; |
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ID: aiam2449OpenMr. Byron Crampton, Truck Body and Equipment Association, 5530 Wisconsin Ave., Suite 1220, Washington, DC 20015; Mr. Byron Crampton Truck Body and Equipment Association 5530 Wisconsin Ave. Suite 1220 Washington DC 20015; Dear Mr. Crampton: This responds to the Truck Body and Equipment Association's November 8 1976, question whether any provision of Standard No. 120, *Tire Selection and Rims for Motor Vehicles Other than Passenger Cars*, prohibits the certification of a vehicle following the addition of an axle system (typically known as a 'tag' or 'pusher' axle) that is not equipped with tires or rims at the time of sale and delivery to the first purchaser for purposes other than resale.; The answer to your question is no. The requirement of S5.1.1 that '. . each vehicle equipped with pneumatic tires for highway service shall be equipped with tires that meet specified requirements . . . ' prohibits the installation of tires that do not meet certain performance requirements, but it is not a requirement that tires be fitted to every axle of a vehicle prior to certification and sale.; I would like to point out that S 567.4(g)(4) of Part 567 *Certification*, requires that a gross axle weight rating be assigned to each axle system. Section S5.1.2 of Standard No. 120 specifies that the GAWR be not more than the sum of the maximum load ratings of the tires fitted to the axle in question. While the agency interprets Standard No. 120 to permit the assignment of a GAWR on the basis of tires listed on the certification plate for that GAWR, the assignment of an arbitrarily high (or low) GAWR for purposes such as avoiding a Federal motor vehicle safety standard (such as Standard No. 121, *Air Brake Systems*), would constitute a violation of S108(a)(1)(D) of the National Traffic and Motor Vehicle Safety Act:; >>>S108(a)(1) No person shall (A) . . . (c) (sic) Fail to issue a certificate required by section 114 of thi title, or issue a certificate to the effect that a motor vehicle or item of motor vehicle equipment conforms to all applicable Federal motor vehicle safety standards, if such person in the exercise of due care has reason to know that such certification is false or misleading in a material respect.<<<; Sincerely, Frank A. Berndt, Acting Chief Counsel |
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ID: aiam4964OpenHerrn. Westermann u. Schmidt Hella KG Hueck & Co. Rixbecker Stra e 75 Postfach 2840 4780 Lippstadt Germany; Herrn. Westermann u. Schmidt Hella KG Hueck & Co. Rixbecker Stra e 75 Postfach 2840 4780 Lippstadt Germany; "Gentlemen: This responds to your FAX of December 9, 1991, to Richar Van Iderstine of this agency. You ask for a definition of two and four headlamp systems, stating that formerly 'this definition was done under para. S4.1.1.36, but today there only remains figure 26, which explains the application of photometric requirements with respect to the bulb or bulb combination used.' You have enclosed sketches of three replaceable bulb headlighting systems and ask for confirmation that each is a two or four headlamp system under Standard No. 108. Standard No. 108 has never contained a specific definition of two or four lamp headlamp systems. Paragraph S4.1.1.36 impliedly defined these systems for headlamps incorporating replaceable bulbs by specifying requirements for the upper and lower beams of headlamp systems consisting of two or four lamps, each containing one or two standardized replaceable light sources. When Standard No. 108 was amended to delete S4.1.1.36, these provisions became part of new paragraph S7.5 Replaceable Bulb Headlamp System. Figure 26 Table of Photometric Requirements was added to illustrate photometric requirements for headlighting systems that use combinations of replaceable bulbs listed in S7.6 Standardized Replaceable Light Sources, and as the systems are described in S7.5. The understanding expressed in your drawings of replaceable bulb headlamp systems is correct. A 4-lamp system is one in which each lamp contains one light source, usually HB3 or HB4 light source for a total of two HB3 and HB4 light sources per system. A 2-lamp system is one in which each lamp typically contains a single dual filament light source such as HB1 or HB5, and achieves both a lower beam and an upper beam, alternatively, each lamp may contain two light sources, typically one HB3 and one HB4 light source, each with individual reflectors, but together with a common housing and lens. This lamp achieves both a lower and an upper beam. Sincerely, Paul Jackson Rice Chief Counsel"; |
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ID: aiam3608OpenMr. Jerome N. Sonosky, Mr. Mark S. McConnell, Hogan & Hartson, 815 Connecticut Avenue, Washington, DC 20006; Mr. Jerome N. Sonosky Mr. Mark S. McConnell Hogan & Hartson 815 Connecticut Avenue Washington DC 20006; Dear Messrs. Sonosky and McConnell: This is in further response to your letter concerning the applicatio of several Federal Motor Vehicle Safety Standards to mopeds. You asked whether Standard No. 108 and Standard No. 127 would preempt States statutes or regulations on the same subjects.; Your specific question on Standard No. 127 was whether section 3 of th standard, which excluded mopeds from the coverage of the standard, would preempt State laws that require all motor vehicles operated on the highways to be equipped with a speedometer. Subsequent to your letter, the agency rescinded Standard No. 127 (47 FR 7250). In rescinding the standard, the agency stated that it recognized that there is a nexus between having a speedometer and motor vehicle safety. Based on available information, however, the agency concluded that the specific requirements of the standard concerning the markings on a speedometer, such as the highlighting of the numeral '55', were not yielding and could not be expected to yield significant safety benefits. Because the marking requirements were not yielding safety benefits, the agency stated that it intended that other levels of government be preempted from establishing similar requirements. In preempting States from establishing marking requirements, the agency did not intend to preempt States from enforcing laws or regulations which only require the presence of a speedometer and do not set marking requirements for the speedometer.; Your final question concerned section 4.1.1.26 of Standard No. 108 which exempts motor-driven cycles whose speed attainable in one mile is 30 mph or less from the requirement that motor vehicles be equipped with turn signal lamps. You asked if that provision preempts State laws to the extent they require all motor vehicles to be equipped with turn signal lamps. The answer is yes.; In adopting section 4.1.1.26, the agency specifically addressed th issue of what turn signal requirements are necessary and appropriate for mopeds. The agency determined that the speed and weight characteristics of mopeds made the problems associated with hand signaling less significant than they are for larger motorcycles. The agency concluded that exempting mopeds from the turn signal requirement would ease the burden of compliance for moped manufacturers without jeopardizing safety. Since Standard No. 108 specifically addresses the issue of what turn signal requirements are applicable to mopeds, States are preempted from establishing or enforcing a safety standard on that aspect of performance that is not identical to the Federal standard.; If you have any further questions, please let me know. Sincerely, Frank Berndt, Chief Counsel |
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ID: aiam1635OpenMr. W. M. Griffith, Secretary, Canadian Truck Trailer Manufacturers Association, P.O. Box 294, Kleinburg, Ontario, Canada; Mr. W. M. Griffith Secretary Canadian Truck Trailer Manufacturers Association P.O. Box 294 Kleinburg Ontario Canada; Dear Mr. Griffith: This responds to your October 11, 1974, request for an interpretatio of the application of Standard No. 121, *Air brake systems*, to Canadian-made truck trailers manufactured in Canada following the effective date of the standard and subsequently used in inter-country commerce.; I have enclosed a copy of a letter on this subject to th representative of another Canadian manufacturer, which should answer your question. Please write again if you have further questions.; Yours truly, Richard B. Dyson, Acting Chief Counsel |
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ID: aiam0927OpenMr. Evan Hammond, Manager-Central Engineering, Trailmobile, 4453 34th Street, Cincinnati, OH 45209; Mr. Evan Hammond Manager-Central Engineering Trailmobile 4453 34th Street Cincinnati OH 45209; Dear Mr. Hammond: This is in reply to your letter of November 3, 1972, in which you as whether a Certification label, a drawing (33-1-78) of which you enclose, will meet both the requirements of the Certification regulations (49 CFR Part 567) and those of proposed Motor Vehicle Safety Standard No. 120, 'Tire and Rim Selection and Rim Performance' (36 F.R. 142730). In our conversation of November 28, 1972, you asked two additional questions--first, whether GAWR for trailers could be expressed as a single figure when the ratings for each axle are identical, and second, as followed up by your letter of November 30, what is the appropriate method for determine GVWR for a semitrailer having a 'sliding-bogie' axle.; The Certification label you have submitted would conform to th requirements of Part 567, and proposed Standard No. 120 if 'rim size' is moved from its location following GAWR and GVWR to the bottom of the label, in proximity to the 'maximum rim load rating.' The Certification regulation does not require rim size to be specified, and rim size would therefore have to appear after the information required by that regulation. The requirements of proposed Standard No. 120 are tentative only, as you must know, and manufacturers should not make permanent plans regarding them until a final rule is issued.; The NHTSA position with respect to GAWR being expressed as one figur when identical axles are involved is that such a method is not consistent with the Certification regulation. Each axle must be listed separately on the Certification label regardless of whether its rating is identical to that of other axles. We have no record of any oral statement to the contrary, and if one was made, as you seem to recall, we regret that it was in error. With respect to specifying GVWR for trailers having sliding-bogie axles, the NHTSA position is that a manufacturer is free to assume the axle to be in either position. If the manufacturer wishes to indicate at which position the rating is based, he may do so on the label, following all required information.; 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.