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: aiam2575OpenMr. Melvin R. Stahl, Vice President, Government Relations, Motorcycle Industry Council, Inc., 1001 Connecticut Avenue, N.W., Washington, D.C. 20036; Mr. Melvin R. Stahl Vice President Government Relations Motorcycle Industry Council Inc. 1001 Connecticut Avenue N.W. Washington D.C. 20036; Dear Mr. Stahl: This is in reply to your letter of April 7, 1977, requestin interpretations with respect to Motor Vehicle Safety Standard No. 123, *Motorcycle Controls and Displays*.; You have asked whether a speedometer may be marked to register speed i kilometers per hour only. The answer is no. Table 3 of Standard No. 123 requires that motorcycle speedometers indicate speed in miles per hour. You have also asked whether a speedometer may be marked to register speed in both miles and kilometers per hour. The answer is yes. The requirement that speedometers be marked in miles per hour is a minimum requirement only and there is no legal objection to a manufacturer adding kilometer markings to the dial.; "Your next question is whether Standard No. 123 preempts a New Yor State law, passed in 1976, that requires speedometers of all motor vehicles manufactured after September 1, 1980, to measure speeds in both miles and kilometers per hour. The answer is yes, assuming that a j motorcycle is defined as a 'motor vehicle' under New York law. As you know 15 U.S.C. 1392(d) provides that no State shall have authority to establish with respect to a motor vehicle a safety standard applicable to the same aspect of performance of such vehicles as a Federal motor vehicle safety standard. Speedometers marking is clearly the same 'aspect of performance' in both the Federal and New York requirements, and it appears that New York would be preempted from requiring a motorcycle manufacturer to mark its speedometer in kilometers, though the manufacturer would not be prohibited by Standard No. 123 from voluntarily doing so."; Your final question is whether NHTSA contemplates changing Standard No 123 'mandating only or optional km/h speedometer markings.' The answer is yes. I enclose a copy of an NPRM published on December 13, 1976, proposing a new standard on *Speedometers and Odometers*. The proposal specifically allows use of kilometer markings on motorcycle speedometers in addition to the required markings in miles per hour. Note, however, that it would not apply to 'motor driven cycles whose speed attainable in one mile is 30 mph or less' (*e.g.*, mopeds) or police motorcycles.; Sincerely, Frank A. Berndt, Acting Chief Counsel |
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ID: aiam0548OpenMr. H. Braun, Engineering Supervisor - Production, Motor Coach Industries, Inc., Pembina, ND 58271; Mr. H. Braun Engineering Supervisor - Production Motor Coach Industries Inc. Pembina ND 58271; Dear Mr. Braun: This is in reply to your letter of October 23, 1972, in which you as whether it is permissible under the Certification regulations for you to list alternative tire sizes and gross axle weight ratings on certification labels for vehicles which you sell without tires, but on which you apparently install them before delivery. You indicate that the tires are supplied by the customer, which he either owns, leases, or purchases from you.; Under the Certification regulation, you may if you wish lis alternative tire sizes, and alternative gross vehicle or gross axle weight ratings, as you described in your letter. If you install the tires, regardless of whether they are owned by the vehicle purchaser, leased, or purchased from you, the tire you install should be one of the alternative sizes listed on the certification label.; Yours truly, Richard B. Dyson, Assistant Chief Counsel |
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ID: aiam2826OpenMr. Warren L. VanderLinden, Sales Manager, Minnesota Motor Company, P.O. Box 505, Fergus Falls, MN 56537; Mr. Warren L. VanderLinden Sales Manager Minnesota Motor Company P.O. Box 505 Fergus Falls MN 56537; Dear Mr. VanderLinden: Administrator Claybrook has asked me to respond to your recent lette concerning the installation of safety belts in the cargo area of a van vehicle for the purpose of securing wheelchair patients. Apparently, your legal counsel has advised you that such installation might be prohibited by Federal law or might give rise to private litigation problems in the future.; In answer to your questions, there is nothing under Federal law or th Federal motor vehicle safety standards that would prevent the installation of safety belts in the cargo area of a van to secure wheelchairs. In fact, Administrator Claybrook and the National Highway Traffic Safety Administration encourage you to make the installation requested by the senior citizens home. The safe transportation of disabled persons is currently a serious problem and every effort should be made to ameliorate the situation.; The only instance in which you would have any responsibilities unde Federal law would be an installation of additional safety belts prior to first purchase of the van by a consumer. In that case you would be a vehicle alteror, (sic) and under our certification regulations you would be required to place an additional label on the vehicle specifying that, as altered, the vehicle is still in compliance with all applicable safety standards (49 CFR 567.7, copy enclosed). For example, you should not destroy the vehicle's compliance with our Fuel System Integrity standard by penetrating the gas tank with the safety belt anchorage bolts.; Concerning your liability in private litigation, the general provision of negligence law would be applicable, as with any maintenance, repair or alteration done by a motor vehicle repair business. I must defer to the advice of your own counsel on that matter, however.; Once again, the agency does encourage the installation of safety belt for the securement of wheelchairs, since the disabled are seriously endangered without some type of restraint to protect them in a crash. Further, I believe that your fears of liability should be minimal as long as the installation is accomplished with normal consideration and due care.; Please contact Hugh Oates of my office if you have any furthe questions (202-426- 2992).; Sincerely, Joseph J. Levin, Jr., Chief Counsel |
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ID: aiam1709OpenMr. Peter N. Lalos, Mason, Fenwick & Lawrence, 310 O F C Building, 1730 Rhode Island Avenue, N.W., Washington, DC 20036; Mr. Peter N. Lalos Mason Fenwick & Lawrence 310 O F C Building 1730 Rhode Island Avenue N.W. Washington DC 20036; Dear Mr. Lalos: This responds to your November 15, 1974, request for a discussion o the responsibilities of a vehicle manufacturer to comply with Federal motor vehicle safety standards, and in particular, Standard No. 121, *Air brake systems*.; The National Traffic and Motor Vehicle Safety Act of 1966 (15 U.S. 1391 et seq.) provides:; >>>S 108. (a) No person shall -- (1) manufacture for sale, sell, offer for sale, or introduce i 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 except as provided in subsection (b) of this section.<<<; Thus, the manufacture or sale of any vehicle which does not meet ever requirement of Standard No. 121 or any other applicable Federal motor vehicle safety standard is a violation of Federal law subject to a civil penalty of not more than $1,000 per violation (S 109). Each vehicle which does not comply with the dynamometer requirements you listed could constitute a separate violation of the act.; You suggested the standard of 'reasonable or due care' as the sol responsibility of a vehicle manufactured under the Safety Act. Section 108(b)(2) in part provides that S 108(a)(1) 'shall not apply to any person who establishes that he did not have reason to know in the exercise of due care' that a vehicle did not comply with an applicable standard. In order to comply with the Safety Act each manufacturer must design his vehicles and test program so as to exercise due care in assuring that each of his vehicles complies with the standard. Calculations based on principles of engineering could constitute an element in the exercise of 'due care'. I enclose a discussion of 'due care' which appeared in the preamble to a recent rulemaking on Standard No. 121.; Yours truly, Richard B. Dyson, Acting Chief Counsel |
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ID: aiam3734OpenMr. M. Iwase, Manager, Technical Administration Department, Koito Manufacturing Co., Ltd., Shizuoka Works, 500, Kitawaki, Shimuzu-shi, Shizuoka-ken, 424, Japan; Mr. M. Iwase Manager Technical Administration Department Koito Manufacturing Co. Ltd. Shizuoka Works 500 Kitawaki Shimuzu-shi Shizuoka-ken 424 Japan; Dear Mr. Iwase: This is in reply to your letter of June 22, 1983, to Mr. Medlin of thi agency asking for an interpretation of the recent amendment to Motor Vehicle Safety Standard No. 108 allowing use of replaceable bulb headlamp systems.; Regarding plastic lens materials, you have asked the limits o luminance transmittance loss and presence of haze after outdoor exposure test. These values are those specified by the referenced SAE standard, J576c.; You have also asked whether an accelerated weathering test i acceptable, such as ASTM E 838. Our reply is that you are free to conduct any accelerated weathering test you deem appropriate to support certification of compliance to Standard No. 108. We have not adopted any such test and will perform our compliance tests according to the 3-year test in SAE J576c.; Regarding the structural configuration of headlamps, you have aske about methods that may be acceptable to joining the lens and reflector, such as glue or welding. Standard No. 108 specifies no method for joining components, and any method is acceptable which results in an indivisible lens-reflector unit. Use of clips to supplement glue is permissible but use of clips alone would not result in an indivisible lens-reflector assembly. There is no objection to use of an additional rubber boot behind the reflector and bulb in the manner depicted in your letter. Drain holes, etc. may be provided as long as the headlamp complies with all the requirements of Standard No. 108. We shall publish in the near future a clearer indication of the headlamp terminal arrangement, as well as the dimensional specifications of the connector to the terminals of the bulb socket. We do not understand your request about the specific dimension and shape of each terminal 'blade' as the length, thickness, and width are already specified in the amendment (Figure 3-3). You have asked also whether the wattage values of 65 for the upper beam and 45 for the lower beam are maximum or nominal values. These values are maximum values.; Finally, concerning patent matters, you have asked whether certai aspects of the bulb and socket assembly are the subjects of patent claims. Ford has indicated in a letter of March 2, 1983, that, 'To facilitate compliance with the standard by all who wish to make or use replaceable bulb headlamps or their components, Ford Motor Company offers to grant royalty-free non-exclusive licenses to all manufacturers of motor vehicles, headlamps, or headlamp components that request such licenses, under U.S. patents and U.S. patent applications which claim these inventions to the extent that their use is needed to employ the proposed optional headlamp system.' If you have further questions on this issue you should write to Ford Motor Company.; I hope that this answers your questions. Sincerely, Frank Berndt, Chief Counsel |
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ID: aiam1359OpenMr. David E. Martin, Manager, General Motors Corporation, Automotive Safety Engineering, Warren, MI 48090; Mr. David E. Martin Manager General Motors Corporation Automotive Safety Engineering Warren MI 48090; Dear Mr. Martin: This is in reply to your letter of December 3, 1973, requestin clarification of paragraph S5.1(c) of Motor Vehicle Safety Standard No. 217, Bus Window Retention and Release.' Your letter, and attached photograph of a push-out window, suggest that the words window frame' in S5.1(c) refer not to the window sash', the structure immediately surrounding the glazing material, but to the side of the bus.; We do not agree. The words window frame' in S5.1(c), with respect t the push out window, refer to the component that interfaces with the glazing.; The intent of S5.1 is to require a window retention system to be stron enough to retain occupants in a crash, at least up to the strength limit of the glazing itself. Since there are no limits on the movement of the window sash' relative to the bus structure, the interpretation you suggest would allow a window system that provides no retentive properties at all, thus defeating one of the main purposes of the standard.; Sincerely, Lawrence R. schneider, Chief Counsel |
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ID: aiam3364OpenJay A. Herbst, Esq., Messrs. Cross, Wrock, Miller & Vieson, 400 Renaissance Center, Suite 1900, Detroit, MI 48243; Jay A. Herbst Esq. Messrs. Cross Wrock Miller & Vieson 400 Renaissance Center Suite 1900 Detroit MI 48243; >>>Re: Model A and Model T Motor Car Reproduction Corp., *NHTS Exemption No. 79-01*<<<, Dear Mr. Herbst, This is in reply to your letter of September 17, 1980. In it you described the plan of your client, Model A and Model T Motor Car Reproduction Corp., to offer a modification of its Model A replica passenger car, currently produced under NHTSA Exemption No. 79-01, and you asked several questions regarding this modification.; Specifically, Model A wishes to offer a modification in which the rea section of the vehicle (rumble seat) is removed and replaced by a flat bed with sides. The seating capacity of the vehicle would be reduced to two passengers and the 'modification will result in a vehicle configuration with the appearance of a Model A pickup truck.' You have asked:; >>>'1. As the modification will occur before complete manufacture o the vehicle, please confirm that the Company will not be considered as 'a person who alters certified vehicles' within the meaning of 49 CFR S568.8.'<<<; Since a vehicle cannot be said to comply until its manufacture i completed, and because certification is not legally required until the vehicle is delivered to a distributor, an alterer's statement is not required when modifications are made upon the assembly line by the certifying party itself, even if the certification label has been attached earlier in the manufacturing process.; You have also asked: >>>'2. Should the Company, for purposes of the certification require under NHTSA Exemption No. 79-01, treat the modified vehicle as a passenger car, or, in the alternative should the Company certify the vehicle as a truck, relying on the same waivers granted the Company under NHTSA Exemption No. 79-01 (and to the extent necessary, the exemption granted for Safety Standard 109 (new pneumatic tires) and and (sic) Safety Standard 110 (tire and rim combinations) for the comparable non-passenger vehicle Safety Standards 119 and 120).'<<<; The question of whether a vehicle is a 'passenger car' or 'truck' fo purposes of compliance with the Federal motor vehicle safety standards must be answered by a manufacturer on the basis of the definitions contained in 49 CFR 571.3(b). Certainly the modification could be viewed as a 'vehicle...designed for carrying 10 persons or less' (passenger car). But if it is 'designed primarily for the transportation of property or special purpose equipment' it becomes a truck. Your letter does not indicate whether the 'flat bed with sides' is intended to be load-bearing or merely decorative, or otherwise state the purpose for which its manufacturer intends it. If it is certified as a 'passenger car,' the exemptions in effect will apply to it.; We surmise, however, that the vehicle is intended as an alternative t the Model A passenger car, as a truck for carrying light loads. Certification as such would require compliance with Standards Nos. 119 and 120. Because the requirements differ from Standards Nos. 109 and 110, Exemption 79-01 would not cover the truck tire and rim standards, and Model A would either have to conform or apply for a temporary exemption.; We would however, consider the vehicle as one covered by the origina exemption if the modification results in no increase in the present gross vehicle weight rating stated on Model A's certification plate. An example of this would be if the modified vehicle's unloaded weight remains the same and its rated cargo load did not exceed 300 pounds (the equivalent of the reduction by two of the number of designated seats). This would insure that the modified vehicle's tires would bear no greater load than that of vehicles presently exempted and permit use of the exemptions currently in effect from the tire and rim standards.; I hope this answers your questions. Sincerely, Frank Berndt, Chief Counsel |
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ID: aiam5463OpenMr. John Sheppard Sales and Marketing Manager Reflexite Canada, Inc. 6790 Kitimat Road, Unit 18 Mississauga Ontario L5N 5L9 Canada; Mr. John Sheppard Sales and Marketing Manager Reflexite Canada Inc. 6790 Kitimat Road Unit 18 Mississauga Ontario L5N 5L9 Canada; "Dear Mr. Sheppard: We have received your letter of November 2, 1994 asking whether certain conspicuity material could be used on trailers required to meet S5.7 of U.S. Federal Motor Vehicle Safety Standard No. 108. You have enclosed samples of the material. The material alternates red and white stripes 'oriented at a 45 degree angle to the edge of the roll.' Rolls are either 6 or 8 inches in width and 'will not have DOT-C2 marking.' In addition, we note that the horizontal length of the red segments is 5 1/2 inches (and presume an equal length for the white segments). Specifically, you have asked whether this material could 'be applied to the lower edge of the vehicle's rear doors as a compliant substitute for the 2' 'block pattern' material currently being used?' Paragraph S5.7's specifications for conspicuity material are intended to ensure uniformity of treatment in order to enhance the ability of drivers of other vehicles to detect large objects in the roadway under conditions when headlamps are used. While S5.7 does not require that the red and white color segments be rectangular, it does establish requirements for their length and width. Under S5.7.1.3(b), each segment shall have a length of 300 mm +/- 150 mm. The color segment separation of 5 1/2 inches on your sample is approximately 140 mm, and thus below the minimum permitted by the standard. Although currently, under S5.7.1.3(d), three widths of retroreflective material are permissible: 50 mm (DOT-C2), 75 mm (DOT-C3), and 100 mm (DOT-C4) and your widths of 6 inches (150 mm) and 8 inches (200mm) do not conform to these specifications, the agency has proposed that these be minimum minimum widths for the DOT grades indicated. We expect a final rule to be issued on this proposal in the near future. Because the retroreflective material discussed above would not comply with Standard No. 108's requirements for color segment length (and currently width), it could not be used as a substitute for the DOT-C2 material that you currently manufacture. Further, geometrically and photometrically complying material would require the appropriate DOT grade identification marking for use on a trailer required to comply with Standard No. 108. Sincerely, Philip R. Recht Chief Counsel"; |
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ID: aiam5199OpenMr. K. Aubrey Hottell Smith and Robson, Inc. Suite 200 354 North Prince St. Lancaster, PA 17603; Mr. K. Aubrey Hottell Smith and Robson Inc. Suite 200 354 North Prince St. Lancaster PA 17603; "Dear Mr. Hottell: This responds to your letter of June 7, 1993 requesting information on 'air bag replacement, air bag indicator light functioning, and any requirements or recommendations for indicator lights to be functional upon resale of a vehicle.' With regard to air bag replacement, I am enclosing a letter, dated January 19, 1990, to Ms. Linda L. Conrad. As explained in this letter, Federal law does not require replacement of a deployed air bag in a used vehicle. In addition, there is no Federal law that prohibits selling a used vehicle with a supplemental restraint that is inoperable because of a previous deployment. With regard to air bag indicator lights, 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. After an air bag is deployed, this indicator would show that the air bag system is not operative. Section 108(a)(2)(A) of the National Traffic and Motor Vehicle Safety Act (15 U.S.C. 1397(a)(2)(A)) provides that: 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. As explained in the Conrad letter enclosed, this provision does not impose an affirmative duty to replace equipment damaged in a crash. Hence, there is no Federal law that prohibits selling a used vehicle with an air bag indicator that is inoperable because of damage in a crash. However, the named commercial entities are prohibited from removing, disabling, or otherwise 'rendering inoperative' a functional indicator. Any violations of this 'render inoperative' prohibition in the Safety Act would subject the violator to a potential civil penalty of up to $1,000 for each violation. As noted in the Conrad letter enclosed, our agency strongly encourages dealers and repair businesses to replace deployed air bags whenever vehicles are repaired or resold, to ensure that the vehicles will continue to provide maximum crash protection for occupants. This recommendation would also include repair or replacement of a non-functioning indicator light. I am also enclosing a copy of the information sheet referred to in the Conrad letter. 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 Enclosures"; |
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ID: aiam0661OpenMr. Edward L. Adams, Route 4, Union Hill, Carbondale, IL 62901; Mr. Edward L. Adams Route 4 Union Hill Carbondale IL 62901; Dear Mr. Adams: This is in reply to your letter of February 17, 1972, in which you as for information on safety specifications as they would apply to travel trailers.; All trailers manufactured for use on the public roads are required t meet applicable Federal Motor Vehicle Safety Standards (FMVSS) in effect on the date of manufacture. Part 567 of Title 49 of the Code of Federal Regulations requires that a certification label be attached to the left front of the trailer. A specific conformity statement is required, among other things, on the label. A copy of the regulation is enclosed.; We do not have information at this time that would add to the articl in the St. Louis Post Dispatch.; Thank you for your interest in the program of the National Highwa Traffic Safety Administration.; Sincerely, Francis Armstrong, Director, Office of Standard Enforcement, Motor 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.